Cancer Chemoprevention by Carotenoids

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Takuji Tanaka

2012-03-01

Full Text Available Carotenoids are natural fat-soluble pigments that provide bright coloration to plants and animals. Dietary intake of carotenoids is inversely associated with the risk of a variety of cancers in different tissues. Preclinical studies have shown that some carotenoids have potent antitumor effects both in vitro and in vivo, suggesting potential preventive and/or therapeutic roles for the compounds. Since chemoprevention is one of the most important strategies in the control of cancer development, molecular mechanism-based cancer chemoprevention using carotenoids seems to be an attractive approach. Various carotenoids, such as β-carotene, a-carotene, lycopene, lutein, zeaxanthin, β-cryptoxanthin, fucoxanthin, canthaxanthin and astaxanthin, have been proven to have anti-carcinogenic activity in several tissues, although high doses of β-carotene failed to exhibit chemopreventive activity in clinical trials. In this review, cancer prevention using carotenoids are reviewed and the possible mechanisms of action are described.

[Coffee in Cancer Chemoprevention].

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Neuwirthová, J; Gál, B; Smilek, P; Urbánková, P

Coffee consumption is associated with a reduced risk of several diseases including cancer. Its chemopreventive effect has been studied in vitro, in animal models, and more recently in humans. Several modes of action have been proposed, namely, inhibition of oxidative stress and damage, activation of metabolizing liver enzymes involved in carcinogen detoxification processes, and anti-inflammatory effects. The antioxidant activity of coffee relies partly on its chlorogenic acid content and is increased during the roasting process. Maximum antioxidant activity is observed for medium-roasted coffee. The roasting process leads to the formation of several components, e.g., melanoidins, which have antioxidant and anti-inflammatory properties. Coffee also contains two specific diterpenes, cafestol and kahweol, which have anticarcinogenic properties. Roasted coffee is a complex mixture of various chemicals. Previous studies have reported that the chemopreventive components present in coffee induce apoptosis, inhibit growth and metastasis of tumor cells, and elicit antiangiogenic effects. A meta-analysis of epidemiological studies showed that coffee consumption is associated with a lower risk of developing various malignant tumors. This review summarizes the molecular mechanisms and the experimental and epidemiological evidence supporting the chemopreventive effect of coffee.Key words: coffee - chemoprevention - antioxidative enzyme - detoxification enzyme - anti-inflammatory effect The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 11. 9. 2016Accepted: 24. 11. 2016.

Chemoprevention of Lung Cancer

Science.gov (United States)

Szabo, Eva; Mao, Jenny T.; Lam, Stephen; Reid, Mary E.

2013-01-01

Background: Lung cancer is the most common cause of cancer death in men and women in the United States. Cigarette smoking is the main risk factor. Former smokers are at a substantially increased risk of developing lung cancer compared with lifetime never smokers. Chemoprevention refers to the use of specific agents to reverse, suppress, or prevent the process of carcinogenesis. This article reviews the major agents that have been studied for chemoprevention. Methods: Articles of primary, secondary, and tertiary prevention trials were reviewed and summarized to obtain recommendations. Results: None of the phase 3 trials with the agents β-carotene, retinol, 13-cis-retinoic acid, α-tocopherol, N-acetylcysteine, acetylsalicylic acid, or selenium has demonstrated beneficial and reproducible results. To facilitate the evaluation of promising agents and to lessen the need for a large sample size, extensive time commitment, and expense, surrogate end point biomarker trials are being conducted to assist in identifying the most promising agents for later-stage chemoprevention trials. With the understanding of important cellular signaling pathways and the expansion of potentially important targets, agents (many of which target inflammation and the arachidonic acid pathway) are being developed and tested which may prevent or reverse lung carcinogenesis. Conclusions: By integrating biologic knowledge, additional early-phase trials can be performed in a reasonable time frame. The future of lung cancer chemoprevention should entail the evaluation of single agents or combinations that target various pathways while working toward identification and validation of intermediate end points. PMID:23649449

Cancer chemopreventive property of Bidens pilosa methanolic ...

African Journals Online (AJOL)

Cancer chemopreventive property of Bidens pilosa methanolic extract on two stage in vivo skin carcinogenesis model. ... In the forestomach, kidney and lung, glutathione S-transferase and DT-diaphorase levels were significantly reduced. Chemopreventive response was calculated by the mean number of papillomas ...

Breast Cancer Profile among Patients with a History of Chemoprevention

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Freya R. Schnabel

2016-01-01

Full Text Available Purpose. This study identifies women with breast cancer who utilized chemoprevention agents prior to diagnosis and describes their patterns of disease. Methods. Our database was queried retrospectively for patients with breast cancer who reported prior use of chemoprevention. Patients were divided into primary (no history of breast cancer and secondary (previous history of breast cancer groups and compared to patients who never took chemoprevention. Results. 135 (6% of 2430 women used chemoprevention. In the primary chemoprevention group (n = 18, 1%, 39% had completed >5 years of treatment, and fully 50% were on treatment at time of diagnosis. These patients were overwhelmingly diagnosed with ER/PR positive cancers (88%/65% and were diagnosed with equal percentages (44% of IDC and DCIS. 117 (87% used secondary chemoprevention. Patients in this group were diagnosed with earlier stage disease and had lower rates of ER/PR-positivity (73%/65% than the nonchemoprevention group (84%/72%. In the secondary group, 24% were on chemoprevention at time of diagnosis; 73% had completed >5 years of treatment. Conclusions. The majority of patients who used primary chemoprevention had not completed treatment prior to diagnosis, suggesting that the timing of initiation and compliance to prevention strategies are important in defining the pattern of disease in these patients.

Antioxidant and antimicrobial activities of Canarium schweinfurthii ...

African Journals Online (AJOL)

diphenylpicrylhydrazyl (DPPH) radical scavenging assay and the -carotene bleaching test. Butylated hydroxytoluene (BHT) was employed as a positive control. The essential oil showed antioxidant and DPPH radical scavenging activities, and it displayed ...

Recovering/recycling of butyl and halogenated butyl rubber via ionizing radiation

International Nuclear Information System (INIS)

Martin, Sandra Regina Scagliusi

2013-01-01

Polymeric materials (plastics and rubbers) attain a continuous and raising proportion of urban and industrial scraps discarded in landfills; their impact on environment are more and more concerning. The implementation of new technologies in order to reduce impacts of plastic waste on the environment, at an effective cost, proved to be a great problem, due to inherent complexity for polymers re-using. Ionizing radiation is capable to modify structure and properties of polymeric material. Butyl and halobutyl rubbers have been used within a comprehensive scale, applications such as tires spare parts and diverse artifacts. The major high energy photon effect, as gamma-rays in butyl and halo butyl rubbers consists in free-radicals generation along changes in mechanical properties.This work aims to the development of controlled degradation processes (devulcanization) of butyl and halo butyl (chlorine and bromine) rubbers, in order to characterize their availability for transformation and modification of properties. Experimental results obtained showed that butyl and halobutyl rubbers,irradiated at 25 kGy and further sheared, are able to be used as an initial point for mixtures with pristine. (author)

Chemopreventive effect of tadalafil in cisplatin-induced ...

African Journals Online (AJOL)

Summary: Nephrotoxicity remains a common untoward effect of cisplatin therapy with limited effective chemopreventive options available till date. This study aims to evaluate the possible chemopreventive effect and mechanism(s) of action of 2 mgkg-1 and 5 mgkg-1 of Tadalafil in cisplatin-induced nephrotoxic rats. In this ...

Ellagitannins in Cancer Chemoprevention and Therapy

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Tariq Ismail

2016-05-01

Full Text Available It is universally accepted that diets rich in fruit and vegetables lead to reduction in the risk of common forms of cancer and are useful in cancer prevention. Indeed edible vegetables and fruits contain a wide variety of phytochemicals with proven antioxidant, anti-carcinogenic, and chemopreventive activity; moreover, some of these phytochemicals also display direct antiproliferative activity towards tumor cells, with the additional advantage of high tolerability and low toxicity. The most important dietary phytochemicals are isothiocyanates, ellagitannins (ET, polyphenols, indoles, flavonoids, retinoids, tocopherols. Among this very wide panel of compounds, ET represent an important class of phytochemicals which are being increasingly investigated for their chemopreventive and anticancer activities. This article reviews the chemistry, the dietary sources, the pharmacokinetics, the evidence on chemopreventive efficacy and the anticancer activity of ET with regard to the most sensitive tumors, as well as the mechanisms underlying their clinically-valuable properties.

Solubilization of meso-carbon microbeads by potassium- or dibutylzinc-promoted butylation and structural analysis of the butylated products; Mesocarbon microbeads no butyl ka ni yoru kayoka to erareta butyl kabutsu no kozo kaiseki

Energy Technology Data Exchange (ETDEWEB)

Murata, S.; Zhang, Y.; Kidena, K.; Nomura, M. [Osaka University, Osaka (Japan). Faculty of Engineering

1996-10-28

Tetrahydrofuran (THF) solubility and structure of the butylated products of meso-carbon microbeads (MCMB) were studied experimentally. In experiment, MCMB-A and MCMB-B obtained from two kinds of coal-tar pitch were used as specimens. MCMBs were butylated by BZ method using dibutylzinc-butyl iodide and KT method using K-butyl iodide-THF, and the butylated products were successfully obtained. The butylated products were investigated through THF solubility test, {sup 13}C-NMR measurement and gel permeation chromatography (GPC) measurement. As the experimental result, a BZ method produced the butylated products at a yield of nearly 170%, while a KT method produced them at a yield of nearly 130%. The THF solubility was estimated to be 89-97%. As the study result of molecular weight distributions by GPC measurement of solvent solubles, the molecular weight of raw material MCMB was estimated to be 590-770 in terms of polystyrene. 6 refs., 2 figs., 1 tab.

Molecular medicine and the development of cancer chemopreventive agents.

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Izzotti, Alberto

2012-07-01

Chemoprevention is effective in inhibiting the onset of cancer in experimental animal models, but the transferability of similar results to humans is questionable. Therefore, reliable intermediate molecular biomarkers are needed to evaluate the efficacy of chemopreventive agents before the onset of cancer. The use of genomic biomarkers is limited by their poor predictive value. Although post-genomic biomarkers (i.e., gene-expression analyses) are useful for evaluating the safety, efficacy, and mechanistic basis of chemopreventive agents, the biomarkers are often poorly related to the phenotype, due to posttranscriptional regulation. Proteome analyses can evaluate preclinical phenotype alterations, but only at low protein counts. MicroRNA alterations, which are essential for the development of cancer, may be modulated by chemopreventive agents. Furthermore, microRNA delivery may be used to counteract carcinogenesis. Exposure to cigarette smoke induces microRNA let-7 downregulation and cell proliferation that can be converted to cell growth arrest and apoptosis upon let-7a transfection. Therefore, microRNAs are reliable biomarkers for evaluating chemoprevention efficacy and may be used to counteract carcinogenesis. © 2012 New York Academy of Sciences.

Effect of Naphthalene, Butylated Hydroxytoluene, Dioctyl Phthalate, and Adipic Dioctyl Ester, Chemicals Found in the Nests of the Formosan Subterranean Termite (Isoptera: Rhinotermitidae) on a Saprophytic Mucor sp.

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Fungi are commonly found associated with termites and their nests. Four chemicals that have been isolated from the nests of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were evaluated to determine their effect on a common nest fungus, a saprophytic Mucor sp. Butylated hydroxyto...

Combination chemoprevention with grape antioxidants.

Science.gov (United States)

Singh, Chandra K; Siddiqui, Imtiaz A; El-Abd, Sabah; Mukhtar, Hasan; Ahmad, Nihal

2016-06-01

Antioxidant ingredients present in grape have been extensively investigated for their cancer chemopreventive effects. However, much of the work has been done on individual ingredients, especially focusing on resveratrol and quercetin. Phytochemically, whole grape represents a combination of numerous phytonutrients. Limited research has been done on the possible synergistic/additive/antagonistic interactions among the grape constituents. Among these phytochemical constituents of grapes, resveratrol, quercetin, kaempferol, catechin, epicatechin, and anthocyanins (cyanidin and malvidin) constitute more than 70% of the grape polyphenols. Therefore, these have been relatively well studied for their chemopreventive effects against a variety of cancers. While a wealth of information is available individually on cancer chemopreventive/anti-proliferative effects of resveratrol and quercetin, limited information is available regarding the other major constituents of grape. Studies have also suggested that multiple grape antioxidants, when used in combination, alone or with other agents/drugs show synergistic or additive anti-proliferative response. Based on strong rationale emanating from published studies, it seems probable that a combination of multiple grape ingredients alone or together with other agents could impart 'additive synergism' against cancer. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The thermal degradation of poly(iso-butyl methacrylate and poly(sec-butyl methacrylate

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IVANKA G. POPOVIC

2000-12-01

Full Text Available The non-oxidative thermal degradation of poly(iso-butyl methacrylate and poly(sec-butyl methacrylate was investigated by studying changes in the polymer residue. Due to the different number of b-hydrogens in their ester substituents, these two polymeric isomers behave differently when subjected to elevated temperatures. Poly(iso-butyl methacrylate degrades quantitatively by depolymerisation with zip lengths of the same order of magnitude as those of poly(methyl methacrylate. Poly(sec-butyl methacrylate degrades by a combined degradation mechanism of depolymerisation and de-esterification. De-esterification becomes a significant thermolysis route at temperatures higher than 240°C.

Targeting NRF2 signaling for cancer chemoprevention

International Nuclear Information System (INIS)

Kwak, Mi-Kyoung; Kensler, Thomas W.

2010-01-01

Modulation of the metabolism and disposition of carcinogens through induction of cytoprotective enzymes is one of several promising strategies to prevent cancer. Chemopreventive efficacies of inducers such as dithiolethiones and sulforaphane have been extensively studied in animals as well as in humans. The KEAP1-NRF2 system is a key, but not unilateral, molecular target for these chemopreventive agents. The transcription factor NRF2 (NF-E2-related factor 2) is a master regulator of the expression of a subset of genes, which produce proteins responsible for the detoxication of electrophiles and reactive oxygen species as well as the removal or repair of some of their damage products. It is believed that chemopreventive enzyme inducers affect the interaction between KEAP1 and NRF2 through either mediating conformational changes of the KEAP1 protein or activating phosphorylation cascades targeting the KEAP1-NRF2 complex. These events in turn affect NRF2 stability and trafficking. Recent advances elucidating the underlying structural biology of KEAP1-NRF2 signaling and identification of the gene clusters under the transcriptional control of NRF2 are facilitating understanding of the potential pleiotropic effects of NRF2 activators and discovery of novel classes of potent chemopreventive agents such as the triterpenoids. Although there is appropriately a concern regarding a deleterious role of the KEAP1-NRF2 system in cancer cell biology, especially as the pathway affects cell survival and drug resistance, the development and the use of NRF2 activators as chemopreventive agents still holds a great promise for protection of normal cells from a diversity of environmental stresses that contribute to the burden of cancer and other chronic, degenerative diseases.

Plant flavonoids in cancer chemoprevention: role in genome stability.

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George, Vazhappilly Cijo; Dellaire, Graham; Rupasinghe, H P Vasantha

2017-07-01

Carcinogenesis is a multistage process that involves a series of events comprising of genetic and epigenetic changes leading to the initiation, promotion and progression of cancer. Chemoprevention is referred to as the use of nontoxic natural compounds, synthetic chemicals or their combinations to intervene in multistage carcinogenesis. Chemoprevention through diet modification, i.e., increased consumption of plant-based food, has emerged as a most promising and potentially cost-effective approach to reducing the risk of cancer. Flavonoids are naturally occurring polyphenols that are ubiquitous in plant-based food such as fruits, vegetables and teas as well as in most medicinal plants. Over 10,000 flavonoids have been characterized over the last few decades. Flavonoids comprise of several subclasses including flavonols, flavan-3-ols, anthocyanins, flavanones, flavones, isoflavones and proanthocyanidins. This review describes the most efficacious plant flavonoids, including luteolin, epigallocatechin gallate, quercetin, apigenin and chrysin; their hormetic effects; and the molecular basis of how these flavonoids contribute to the chemoprevention with a focus on protection against DNA damage caused by various carcinogenic factors. The present knowledge on the role of flavonoids in chemoprevention can be used in developing effective dietary strategies and natural health products targeted for cancer chemoprevention. Copyright © 2016 Elsevier Inc. All rights reserved.

Australian clinicians and chemoprevention for women at high familial risk for breast cancer

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Keogh Louise A

2009-05-01

Full Text Available Abstract Objectives Effective chemoprevention strategies exist for women at high risk for breast cancer, yet uptake is low. Physician recommendation is an important determinant of uptake, but little is known about clinicians' attitudes to chemoprevention. Methods Focus groups were conducted with clinicians at five Family Cancer Centers in three Australian states. Discussions were recorded, transcribed and analyzed thematically. Results Twenty three clinicians, including genetic counselors, clinical geneticists, medical oncologists, breast surgeons and gynaecologic oncologists, participated in six focus groups in 2007. The identified barriers to the discussion of the use of tamoxifen and raloxifene for chemoprevention pertained to issues of evidence (evidence for efficacy not strong enough, side-effects outweigh benefits, oophorectomy superior for mutation carriers, practice (drugs not approved for chemoprevention by regulatory authorities and not government subsidized, chemoprevention not endorsed in national guidelines and not many women ask about it, and perception (clinicians not knowledgeable about chemoprevention and women thought to be opposed to hormonal treatments. Conclusion The study demonstrated limited enthusiasm for discussing breast cancer chemoprevention as a management option for women at high familial risk. Several options for increasing the likelihood of clinicians discussing chemoprevention were identified; maintaining up to date national guidelines on management of these women and education of clinicians about the drugs themselves, the legality of "off-label" prescribing, and the actual costs of chemopreventive medications.

Curcumin in chemoprevention of breast cancer

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Katarzyna Terlikowska

2014-01-01

Full Text Available Breast cancer is the most common malignant cancer among women, both in Poland and worldwide. Due to the constantly increasing number of breast cancer cases, it is vital to develop effective activities in primary and secondary prevention. One of the promising methods of best value, connecting both types of cancer prevention, appears to be chemoprevention. Chemoprevention uses natural or synthetic compounds to inhibit, delay or reverse the process of carcinogenesis. Among ingredients of natural origin, great attention is paid to curcumin – a broad-spectrum anti-cancer polyphenol derivative, extracted from the rhizome of Curcuma longa L. Curcumin has a number of chemopreventive properties such as anti-inflammatory activity, induction of apoptosis, inhibition of angiogenesis as well as tumor metastasis. Numerous in vitro and in vivo studies have demonstrated the mentioned anti-cancer effect in the epithelial breast cell line MCF-10A and in the epithelial breast cell lines MCF-7, BT-474, SK-BR-3-hr and MDA-MB-231. The main problem associated with the use of curcumin as a chemopreventive agent in humans is its low absorption from the gastrointestinal tract, poor solubility in body fluids and low bioavailability. Current studies are underway to increase the bioavailability and effectiveness of curcumin in vivo. Good results in the prevention and the treatment of breast cancer could be ensured by curcumin nanoparticles coated with albumin, known as nanocurcumin. The studies using nanocurcumin, however, are still in the preclinical stage, which is why there is a need to conduct extensive long-term randomized clinical trials to determine its effectiveness.

SVOC exposure indoors: fresh look at dermal pathways

DEFF Research Database (Denmark)

Weschler, Charles J.; Nazaroff, W. W.

2012-01-01

of SVOCs that strongly sorb to skin-surface lipids. Air-to-skin transdermal uptake is estimated to be comparable to or larger than inhalation intake for many SVOCs of current or potential interest indoors, including butylated hydroxytoluene, chlordane, chlorpyrifos, diethyl phthalate, Galaxolide, geranyl...

Surface-Tolerant Coatings for Aircraft Hangars, Flight Control Tower, and Deluge Tanks at Fort Campbell

Science.gov (United States)

2007-06-01

to chalking. Fluorinated polymers are recognized as the most durable coatings in terms of preservation of appearance. Architectural building panels...phosphate) 19.4 Percent by Weight Film-Former phenolic varnish 55.3 Percent by Weight Antioxidant butylated hydroxytoluene (BHT) 0.43 Percent

Chemopreventive properties of curcumin analogues ...

African Journals Online (AJOL)

Chemopreventive properties of curcumin analogues, ... These compounds .... using microscope with 400 × magnification. APC ... Figure 3: Microscopic images of rat colorectal tissue stained with APC rabbit polyclonal antibody with different.

Prostate cancer chemoprevention: Current status and future prospects

International Nuclear Information System (INIS)

Gupta, Sanjay

2007-01-01

Chemoprevention is a strategy that aims to reduce the incidence and burden of cancer through the development of agents to prevent, reverse or delay the carcinogenic process. Prostate cancer is a suitable target for prevention because it has a high incidence and prevalence, as well as a long latency and disease-related mortality, and furthermore it is a disease in which lifestyle and environmental factors may play critical roles. The development of chemoprevention strategies against prostate cancer will have a huge impact, both medically and economically. Large-scale clinical trials suggest that some agents such as selenium, lycopene, soy, green tea, vitamins D and E, anti-inflammatory and inhibitors of 5α-reductase are effective in preventing prostate cancer. Although each agent has the potential to affect the natural history of the disease, it is important to develop strategies to strategically proceed for the design and selection of test agents in order to demonstrate clinical benefit with the minimum of adverse effects. Appropriate selection of agent(s), disease stage, trial design and endpoints is critical in selecting the most promising regimens to accomplish these goals. This review highlights the present status of prostate cancer chemoprevention and discusses future prospects for chemopreventive strategies that are safe and clinically beneficial

A Chemopreventive Nanodiamond Platform for Oral Cancer Treatment.

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Yen, Albert; Zhang, Kangyi; Daneshgaran, Giulia; Kim, Ho-Joong; Ho, Dean

2016-02-01

Standard oral cancer therapy generally includes a combination of surgery with chemotherapy and/or radiotherapy. This treatment paradigm has not changed in some time. In this paper, we propose a chemopreventive nanodiamond platform for the delivery of celecoxib (Celebrex) to oral cancer lesions. This innovative platform allows for sustained drug release under physiological conditions, potentially enhancing chemopreventive efficacy of celecoxib without the physical and toxicological damage associated with conventional means of drug delivery.

Advanced Drug-Delivery Systems of Curcumin for Cancer Chemoprevention

Science.gov (United States)

Bansal, Shyam S.; Goel, Mehak; Aqil, Farrukh; Vadhanam, Manicka V.; Gupta, Ramesh C.

2011-01-01

From ancient times, chemopreventive agents have been used to treat/prevent several diseases, including cancer. They are found to elicit a spectrum of potent responses including anti-inflammatory, anti-oxidant, anti-proliferative, anti-carcinogenic, and anti-angiogenic activity in various cell culture and some animal studies. Research over the past four decades has shown that chemopreventives affect a number of proteins involved in various molecular pathways that regulate inflammatory and carcinogenic responses in a cell. Various enzymes, transcription factors, receptors, and adhesion proteins are also affected by chemopreventives. Although, these natural compounds have shown significant efficacy in cell-culture studies, they elicited limited efficacy in various clinical studies. Their introduction into the clinical setting is hindered largely by their poor solubility, rapid metabolism, or a combination of both, ultimately resulting in poor bioavailability upon oral administration. Therefore, to circumvent these limitations and to ease their transition to clinics, alternate strategies should be explored. Drug delivery systems such as nanoparticles, liposomes, microemulsions, and polymeric implantable devices are emerging as one of the viable alternatives that have been demonstrated to deliver therapeutic concentrations of various potent chemopreventives such as curcumin, ellagic acid, green tea polyphenols, and resveratrol into the systemic circulation. In this review article, we have attempted to provide a comprehensive outlook for these delivery approaches, using curcumin as a model agent, and discussed future strategies to enable the introduction of these highly potent chemopreventives into a physician’s armamentarium. PMID:21546540

Antioxidant Activities of á-Tocopherol, Herbalox and ...

African Journals Online (AJOL)

This study was carried out to determine possible synergism and antagonism in blends of natural and synthetic antioxidants for protection of palm olein at high temperatures. Three primary antioxidants: (±)-á-tocopherol (Vitamin E), Rosemary extract (Herbalox) and butylated hydroxytoluene (BHT) were used in a mixture ...

Effects of heat and ultraviolet radiation on the oxidative stability of pine nut oil supplemented with carnosic acid.

Science.gov (United States)

Wang, Han; Zu, Ge; Yang, Lei; Zu, Yuan-gang; Wang, Hua; Zhang, Zhong-hua; Zhang, Ying; Zhang, Lin; Wang, Hong-zheng

2011-12-28

The effects of carnosic acid (CA) of different concentrations (0.05, 0.1, and 0.2 mg/g) and two common antioxidants (butylated hydroxytoluene and α-tocopherol) on oxidative stability in pine nut oil at different accelerated conditions (heating and ultraviolet radiation) were compared. The investigation focused on the increase in peroxide and conjugated diene values, as well as free fatty acid and thiobarbituric acid-reactive substances. The changes in trans fatty acid and aldehyde compound contents were investigated by Fourier transform infrared spectroscopy, while the changes in pinolenic acid content were monitored by gas chromatography-mass spectrometry. The results show that CA was more effective in restraining pine nut oil oxidation under heating, UV-A and UV-B radiation, in which a dose-response relationship was observed. The antioxidant activity of CA was stronger than that of α-tocopherol and butylated hydroxytoluene. Pine nut oil supplemented with 0.2 mg/g CA exhibited favorable antioxidant effects and is preferable for effectively avoiding oxidation.

Molecular Mechanisms Behind the Chemopreventive Effects of Anthocyanidins

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De-Xing Hou

2004-01-01

Full Text Available Anthocyanins are polyphenolic ring-based flavonoids, and are widespread in fruits and vegetables of red-blue color. Epidemiological investigations and animal experiments have indicated that anthocyanins may contribute to cancer chemoprevention. The studies on the mechanism have been done recently at molecular level. This review summarizes current molecular bases for anthocyanidins on several key steps involved in cancer chemoprevention: (i inhibition of anthocyanidins in cell transformation through targeting mitogen-activated protein kinase (MAPK pathway and activator protein 1 (AP-1 factor; (ii suppression of anthocyanidins in inflammation and carcinogenesis through targeting nuclear factor kappa B (NF-κB pathway and cyclooxygenase 2 (COX-2 gene; (iii apoptotic induction of cancer cells by anthocyanidins through reactive oxygen species (ROS / c-Jun NH2-terminal kinase (JNK-mediated caspase activation. These data provide a first molecular view of anthocyanidins contributing to cancer chemoprevention.

Chemoprevention by WR-2721

Energy Technology Data Exchange (ETDEWEB)

Grdina, D.J. [Argonne National Lab., IL (United States)]|[Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology; Carnes, B.A. [Argonne National Lab., IL (United States)

1993-05-01

WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] is an effective chemopreventive agent. C57BL {times} BALB/c F{sub 1} female mice, were exposed to a single whole-body dose of 206 cGy from a {sup 60}Co photon source. Those groups treated with VATR-2721 (400 mg/kg) were administered the agent i.p. 30 min prior to irradiation. Over 90% of deaths were determined to be due to tumor involvement. WR-2721 afforded significant protection against life shortening due to radiation-induced tumors of connective tissue and epithelial tissue origins. Subsequent survival time in WR-2721-treated and irradiated animals as compared to matched irradiated-only controls was extended up to 59 days. A single exposure of animals to VVR-2721 did not affect the cumulative survival curves for unirradiated mice. WR-2721 possesses chemopreventive properties which can be clinically exploited to reduce the risk to therapy-induced secondary cancers in patients who otherwise would have an excellent prognosis for cure and long-term survival.

Chemoprevention by WR-2721

Energy Technology Data Exchange (ETDEWEB)

Grdina, D.J. (Argonne National Lab., IL (United States) Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology); Carnes, B.A. (Argonne National Lab., IL (United States))

1993-01-01

WR-2721 [S-2-(3-aminopropylamino)ethylphosphorothioic acid] is an effective chemopreventive agent. C57BL [times] BALB/c F[sub 1] female mice, were exposed to a single whole-body dose of 206 cGy from a [sup 60]Co photon source. Those groups treated with VATR-2721 (400 mg/kg) were administered the agent i.p. 30 min prior to irradiation. Over 90% of deaths were determined to be due to tumor involvement. WR-2721 afforded significant protection against life shortening due to radiation-induced tumors of connective tissue and epithelial tissue origins. Subsequent survival time in WR-2721-treated and irradiated animals as compared to matched irradiated-only controls was extended up to 59 days. A single exposure of animals to VVR-2721 did not affect the cumulative survival curves for unirradiated mice. WR-2721 possesses chemopreventive properties which can be clinically exploited to reduce the risk to therapy-induced secondary cancers in patients who otherwise would have an excellent prognosis for cure and long-term survival.

Effect of α-tocopherol, butylated-hydroxytoluene and hydroxy-anisole on the activation and binding of aflatoxin B1 to macromolecules

International Nuclear Information System (INIS)

Ch'ih, J.J.; Biedrzycka, D.; Devlin, T.M.

1987-01-01

The anti-oxidants, α-tocopherol(TPA), butylated-hydroxy-toluene(BHT) and hydroxyanisole(BHA) inhibit the carcinogenic and toxic effects of a variety of chemical compounds, their effect on aflatoxin B 1 (AFB 1 ) activation and binding was examined utilizing rat liver microsomes and cells. With a NADPH generating system, oxygen, microsomes, [ 3 H]-AFB 1 , 2.2 pmoles/h/mg protein was activated and bound to macromolecules. In hepatocytes, 3.4 and 1.4 pmoles of AFB 1 per 10 6 cells were taken up and bound to macromolecules, whereas the nucleic acid fraction contained 0.19 pmoles of bound AFB 1 . Moderate decreases of AFB 1 activation and binding were observed when TPA was present in both cell-free and hepatocytes systems. Only in hepatocytes, BHT inhibited the AFB 1 uptake and binding to nucleic acids. BHA, however, inhibited microsomal activation of AFB 1 by 73%; maximum inhibition was reached at 1 mM. AFB 1 uptake, and binding to nucleic acids were inhibited by 65% and 79% by BHA. GSH-transferase activity of cells treated with these agents was not altered. The effect of BHA at various concentrations on AFB activation was compared with cytochrome P-450 inhibitors; the ED 50 of SKF 525A, BHA and metyrapone was 9 uM, 80 uM and 380 uM respectively. The data suggest that TPA, BHA and BHT exert their effect by different mechanisms

The Role of Nutraceuticals in Chemoprevention and Chemotherapy and Their Clinical Outcomes

Directory of Open Access Journals (Sweden)

Sabita N. Saldanha

2012-01-01

Full Text Available The genesis of cancer is often a slow process and the risk of developing cancer increases with age. Altering a diet that includes consumption of beneficial phytochemicals can influence the balance and availability of dietary chemopreventive agents. In chemopreventive approaches, foods containing chemicals that have anticancer properties can be supplemented in diets to prevent precancerous lesions from occurring. This necessitates further understanding of how phytochemicals can potently maintain healthy cells. Fortunately there is a plethora of plant-based phytochemicals although few of them are well studied in terms of their application as cancer chemopreventive and therapeutic agents. In this analysis we will examine phytochemicals that have strong chemopreventive and therapeutic properties in vitro as well as the design and modification of these bioactive compounds for preclinical and clinical applications. The increasing potential of combinational approaches using more than one bioactive dietary compound in chemoprevention or cancer therapy will also be evaluated. Many novel approaches to cancer prevention are on the horizon, several of which are showing great promise in saving lives in a cost-effective manner.

Beneficial and adverse effects of chemopreventive agents

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Mu; Park, Kwang-Kyun

2003-03-01

The beneficial and adverse effects of some chemopreventive agents, such as Vitamins A, C, E, beta-carotene, indole-3-carbinol, capsaicin, garlic, and aloe are reviewed. Two large randomized trials with a lung cancer endpoint, the Alpha-Tocopherol, Beta-Carotene (ATBC) Prevention Study and the Beta-Carotene and Retinol Efficacy Trial (CARET), suggested that antioxidants might be harmful in smokers. However, the results of the Linxian study and of the ATBC or the CARET studies were significantly different in this respect, and therefore, the relationship between antioxidant and carcinogenesis remains open to debate. Indole-3-carbinol has cancer promoting activities in the colon, thyroid, pancreas, and liver, whereas capsaicin alters the metabolism of chemical carcinogens and may promote carcinogenesis at high doses. Organosulfur compounds and selenium from garlic have no or a little enhancing effect on cancer promotion stage. Information upon chemopreventive mechanisms that inhibit carcinogenesis is imperfect, although the causes and natures of certain human cancers are known. Therefore, definitive preventive guidelines should be carefully offered for various types of tumors, which properly consider ethnic variations, and the efficacies and the safety of chemopreventive agents.

Beneficial and adverse effects of chemopreventive agents

International Nuclear Information System (INIS)

Lee, Byung Mu; Park, Kwang-Kyun

2003-01-01

The beneficial and adverse effects of some chemopreventive agents, such as Vitamins A, C, E, beta-carotene, indole-3-carbinol, capsaicin, garlic, and aloe are reviewed. Two large randomized trials with a lung cancer endpoint, the Alpha-Tocopherol, Beta-Carotene (ATBC) Prevention Study and the Beta-Carotene and Retinol Efficacy Trial (CARET), suggested that antioxidants might be harmful in smokers. However, the results of the Linxian study and of the ATBC or the CARET studies were significantly different in this respect, and therefore, the relationship between antioxidant and carcinogenesis remains open to debate. Indole-3-carbinol has cancer promoting activities in the colon, thyroid, pancreas, and liver, whereas capsaicin alters the metabolism of chemical carcinogens and may promote carcinogenesis at high doses. Organosulfur compounds and selenium from garlic have no or a little enhancing effect on cancer promotion stage. Information upon chemopreventive mechanisms that inhibit carcinogenesis is imperfect, although the causes and natures of certain human cancers are known. Therefore, definitive preventive guidelines should be carefully offered for various types of tumors, which properly consider ethnic variations, and the efficacies and the safety of chemopreventive agents

Acceptance and adherence to chemoprevention among women at increased risk of breast cancer.

Science.gov (United States)

Roetzheim, Richard G; Lee, Ji-Hyun; Fulp, William; Matos Gomez, Elizabeth; Clayton, Elissa; Tollin, Sharon; Khakpour, Nazanin; Laronga, Christine; Lee, Marie Catherine; Kiluk, John V

2015-02-01

Chemoprevention is an option for women who are at increased risk of breast cancer (five year risk ≥1.7%). It is uncertain, however, how often women accept and complete five years of therapy and whether clinical or demographic factors predict completion. Medical records were abstracted for 219 women whose five year risk of breast cancer was ≥1.7% and who were offered chemoprevention while attending a high risk breast clinic at the Moffitt Cancer Center. We examined the likelihood of accepting chemoprevention and completing five years of therapy, and potential clinical and demographic predictors of these outcomes, using multivariable logistic regression and survival analysis models. There were 118/219 women (54.4%) who accepted a recommendation for chemoprevention and began therapy. The likelihood of accepting chemoprevention was associated with lifetime breast cancer risk and was higher for women with specific high risk conditions (lobular carcinoma in situ and atypical ductal hyperplasia). Women with osteoporosis and those that consumed alcohol were also more likely to accept medication. There were 58/118 (49.2%) women who stopped medication at least temporarily after starting therapy. Based on survival curves, an estimated 60% of women who begin chemoprevention will complete five years of therapy. A substantial percentage of women at increased risk of breast cancer will decline chemoprevention and among those that accept therapy, approximately 40% will not be able to complete five years of therapy because of side effects. Copyright © 2014 Elsevier Ltd. All rights reserved.

Compound list: butylated hydroxyanisole [Open TG-GATEs

Lifescience Database Archive (English)

Full Text Available butylated hydroxyanisole BHA 00156 ftp://ftp.biosciencedbc.jp/archive/open-tggates/...LATEST/Human/in_vitro/butylated_hydroxyanisole.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/o...pen-tggates/LATEST/Rat/in_vivo/Liver/Single/butylated_hydroxyanisole.Rat.in_vivo.Liver.Single.zip ftp://ftp....biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/butylated_hydroxyanisole.Rat.in_vivo.Liver.Repeat.zip ...

An efficient and highly selective ortho-tert-butylation of p-cresol with methyl tert-butyl ether catalyzed by sulfonated ionic liquids

Directory of Open Access Journals (Sweden)

Alamdari Reza Fareghi

2014-01-01

Full Text Available A novel series of sulfonic acid-functionalized ionic liquids (SFILs was found to act as efficient catalysts for ortho-tert-butylation of p-cresol with methyl tert-butyl ether (MTBE as the tert-butylating agent without an added solvent. The mono o-tert-butylated product was obtained in up to 80.4% isolated yield and 95.2% selectivity under such green conditions. No O-tert-butylated byproducts were formed.

Cancer chemopreventive and therapeutic effects of diosgenin, a food saponin.

Science.gov (United States)

Raju, Jayadev; Mehta, Rekha

2009-01-01

Cancer chemoprevention is a strategy taken to retard, regress, or resist the multistep process of carcinogenesis, including the blockage of its vital morphogenetic milestones viz. normal-preneoplasia-neoplasia-metastasis. For several reasons, including safety, minimal (or no) toxicity and side-effects, and better availability, alternatives such as naturally occurring phytochemicals that are found in foods are becoming increasingly popular over synthetic drugs. Food saponins have been used in complimentary and traditional medicine against a variety of diseases including several cancers. Diosgenin, a naturally occurring steroid saponin found abundantly in legumes and yams, is a well-known precursor of various synthetic steroidal drugs that are extensively used in the pharmaceutical industry. Over the past decade, a series of preclinical and mechanistic studies have been conducted to understand the role of diosgenin as a chemopreventive/therapeutic agent against several cancers. This review highlights the biological activity of diosgenin that contributes to cancer chemoprevention and control. The anticancer mode of action of diosgenin has been demonstrated via modulation of multiple cell signaling events involving critical molecular candidates associated with growth, differentiation, apoptosis, and oncogenesis. Altogether, these preclinical and mechanistic findings strongly implicate the use of diosgenin as a novel, multitarget-based chemopreventive or therapeutic agent against several cancer types. Future research in this field will help to establish not only whether diosgenin is safe and efficacious as a chemopreventive agent against several human cancers, but also to develop and evaluate standards of evidence for health claims for diosgenin-containing foods as they become increasingly popular and enter the marketplace labeled as functional foods and nutraceuticals.

Radiochemical study of isomerization of free butyl cations

International Nuclear Information System (INIS)

Sinotova, E.N.; Nefedov, V.D.; Skorokhodov, S.S.; Arkhipov, Yu.M.

1987-01-01

Ion-molecular reactions of free butyl cations, generated by nuclear chemical method, with carbon monoxide containing small quantities of ethanol vapors are studied. Carbon monoxide was used to fix instable butyl cations in the form of corresponding acyl ions. Ester of α-methyl-butyric acid appears to be the only product of free butyl cation interaction with carbon monoxide in the presence of ethanol vapors. That means, that up to the moment of butyl cation reaction with carbon monoxide, the primary butyl cations are almost completely isomerized into secondary in agreement with results of previous investigations. This allows one to study free butyl cation isomerization process according to ion-molecular reaction product isomeric composition

Chemical carcinogenesis and chemoprevention: Scientific priority ...

African Journals Online (AJOL)

Occupational cancers are now a serious concern in industrializing developing countries where exposure levels to hazardous chemicals considerably exceed regulatory limits established in industrialized countries. The association between increasing use of chemicals and associated disorders and chemoprevention or ...

Evaluation of the Antimicrobial and Antioxidant Activities of Origanum dictamnus Extracts before and after Encapsulation in Liposomes

Directory of Open Access Journals (Sweden)

John Tsaknis

2007-05-01

Full Text Available The antioxidant and antimicrobial activity of methanol or dichloromethane extracts of O. dictamnus, produced from wild and organic cultivated specimens, were determined. The Rancimat and malondialdehyde (MDA by HPLC methods were used to measure the antioxidant action, in comparison with that of the common commercial antioxidants butylated hydroxytoluene (BHT and α-tocopherol. The extracts that presented high antioxidant activity were encapsulated in liposomes and their antioxidant action was again estimated using differential scanning calorimetry (DSC. Thermaloxidative decomposition of the samples (pure liposomes and encapsulated extracts and the modification of the main transition temperature for the lipid mixture and the splitting of the calorimetric peak in the presence of the antioxidants were also studied by the DSC method. All extracts showed antioxidant and antimicrobial activities. Their action proved superior to α-tocopherol. The methanol extract of organic cultivated O. dictamnus (240 ppm showed higher activity than butylated hydroxytoluene. After encapsulation in liposomes the antioxidant as well as antimicrobial activities proved to be higher than those of the same extracts in pure form.

COX-independent mechanisms of cancer chemoprevention by anti-inflammatory drugs

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Evrim eGurpinar

2013-07-01

Full Text Available Epidemiological and clinical studies suggest that non-steroidal anti-inflammatory drugs (NSAIDs, including cyclooxygenase (COX-2 selective inhibitors, reduce the risk of developing cancer. Experimental studies in human cancer cell lines and rodent models of carcinogenesis support these observations by providing strong evidence for the antineoplastic properties of NSAIDs. The involvement of COX-2 in tumorigenesis and its overexpression in various cancer tissues suggest that inhibition of COX-2 is responsible for the chemopreventive efficacy of these agents. However, the precise mechanisms by which NSAIDs exert their antiproliferative effects are still a matter of debate. Numerous other studies have shown that NSAIDs can act through COX-independent mechanisms. This review provides a detailed description of the major COX-independent molecular targets of NSAIDs and discusses how these targets may be involved in their anticancer effects. Toxicities resulting from COX inhibition and the suppression of prostaglandin synthesis preclude the long-term use of NSAIDs for cancer chemoprevention. Furthermore, chemopreventive efficacy is incomplete and treatment often leads to the development of resistance. Identification of alternative NSAID targets and elucidation of the biochemical processes by which they inhibit tumor growth could lead to the development of safer and more efficacious drugs for cancer chemoprevention.

Natural and synthetic antioxidants: Influence on the oxidative stability of biodiesel synthesized from non-edible oil

Energy Technology Data Exchange (ETDEWEB)

Sarin, Amit [Department of Applied Sciences, Amritsar College of Engineering and Technology, Manawala, Amritsar-143001, Punjab (India); Singh, N.P. [Punjab Technical University, Jalandhar (India); Sarin, Rakesh; Malhotra, R.K. [Indian Oil Corporation Ltd., R and D Centre, Sector-13, Faridabad-121007 (India)

2010-12-15

According to the proposed National Mission on Biodiesel in India, we have undertaken studies on the oxidative stability of biodiesel synthesized from tree borne non-edible oil seeds jatropha. Neat jatropha biodiesel exhibited oxidation stability of 3.95 h and research was conducted to investigate the influence of natural and synthetic antioxidants on the oxidation stability of jatropha methyl ester. Antioxidants namely {alpha}-tocopherol, tert-butylated hydroxytoluene, tert-butylated phenol derivative, octylated butylated diphenyl amine, and tert-butylhydroxquinone were doped to improve the oxidation stability. It was found that both types of antioxidants showed beneficial effects in increasing the oxidation stability of jatropha methyl ester, but comparatively, the synthetic antioxidants were found to be more effective. (author)

Combination chemoprevention with diclofenac, calcipotriol and difluoromethylornithine inhibits development of non-melanoma skin cancer in mice

DEFF Research Database (Denmark)

Pommergaard, Hans-Christian; Burcharth, Jakob; Rosenberg, Jacob

2013-01-01

Background/Aim: With increasing incidence of non-melanoma skin cancer (NMSC), focus on chemoprevention of this disease is growing. The aim of this study was to evaluate topical combination therapies as chemoprevention of UV radiation-induced tumors in a mouse model.......Background/Aim: With increasing incidence of non-melanoma skin cancer (NMSC), focus on chemoprevention of this disease is growing. The aim of this study was to evaluate topical combination therapies as chemoprevention of UV radiation-induced tumors in a mouse model....

Butyl Rubber: Compound Development and Characterization

National Research Council Canada - National Science Library

Sloan, James

2000-01-01

...), to develop the standard butyl rubber compound. The strategy of this work was to compound- and compression-mold high-quality, uniform butyl rubber experimental sheets and to evaluate their cure properties, mechanical properties...

Chemoprevention of esophageal squamous cell carcinoma

International Nuclear Information System (INIS)

Stoner, Gary D.; Wang Lishu; Chen Tong

2007-01-01

Esophageal squamous cell carcinoma (SCC) is responsible for approximately one-sixth of all cancer-related mortality worldwide. This malignancy has a multifactorial etiology involving several environmental, dietary and genetic factors. Since esophageal cancer has often metastasized at the time of diagnosis, current treatment modalities offer poor survival and cure rates. Chemoprevention offers a viable alternative that could well be effective against the disease. Clinical investigations have shown that primary chemoprevention of this disease is feasible if potent inhibitory agents are identified. The Fischer 344 (F-344) rat model of esophageal SCC has been used extensively to investigate the biology of the disease, and to identify chemopreventive agents that could be useful in human trials. Multiple compounds that inhibit tumor initiation by esophageal carcinogens have been identified using this model. These include several isothiocyanates, diallyl sulfide and polyphenolic compounds. These compounds influence the metabolic activation of esophageal carcinogens resulting in reduced genetic (DNA) damage. Recently, a few agents have been shown to inhibit the progression of preneoplastic lesions in the rat esophagus into tumors. These agents include inhibitors of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF) and c-Jun [a component of activator protein-1 (AP-1)]. Using a food-based approach to cancer prevention, we have shown that freeze-dried berry preparations inhibit both the initiation and promotion/progression stages of esophageal SCC in F-344 rats. These observations have led to a clinical trial in China to evaluate the ability of freeze-dried strawberries to influence the progression of esophageal dysplasia to SCC

Antioxidant activity of extracts from the wood and bark of Port OrFord cedar

Science.gov (United States)

Heng Gao; Todd F. Shupe; Thomas L. Eberhardt; Chung Y. Hse

2007-01-01

Heartwood, sapwood, and inner and outer bark of Port Orford cedar were extracted with methanol, and the extracts evaluated for antioxidant activity. The total phenol content (TPC) of the extracts was determined by the Folin-Ciocalteu method and expressed as gallic acid equivalent (GAE). Butylated hydroxytoluene was used as a positive control in the free-radical-...

Arsenic and skin cancer – Case report with chemoprevention

Directory of Open Access Journals (Sweden)

Uwe Wollina

2016-04-01

Full Text Available ABSTRACT Introduction: Arsenic is a potentially hazardous metalloid that can cause skin cancer. We want to demonstrate a case of chronic arsenicosis and the potential of chemoprevention with retinoids. Case Report: This is a case report of a 72-year-old male patient who was exposed to arsenics by dust and direct skin contact over 3 years in a chemical plant in the late fourties. He developed multiple arsenic keratosis clincialll resembling actinic keratoses, Bowen’s disease and palmar minute keratoses. To prevent a transformation into invasive cancer and to lower the burden of precancerous and in situ cancer lesions, he was treated orally with acitretin 20 mg/day. During 9 months of chemopreventive retinoid therapy a partial response of pre-existent skin lesions was noted. Treatment was well tolerated. During follow-up of 5 years no invasive malignancy developed. Conclusions: Intense exposure to arsenics during a relatively short period of 3 years bears a life-long health hazard with the delayed development of multiple in situ carcinomas and precancerous lesions. Chemoprevention with retinoids can induce a partial response.

Colorectal cancer chemoprevention: the potential of a selective approach.

Science.gov (United States)

Ben-Amotz, Oded; Arber, Nadir; Kraus, Sarah

2010-10-01

Colorectal cancer (CRC) is a leading cause of cancer death, and therefore demands special attention. Novel recent approaches for the chemoprevention of CRC focus on selective targeting of key pathways. We review the study by Zhang and colleagues, evaluating a selective approach targeting APC-deficient premalignant cells using retinoid-based therapy and TNF-related apoptosis-inducing ligand (TRAIL). This study demonstrates that induction of TRAIL-mediated death signaling contributes to the chemopreventive value of all-trans-retinyl acetate (RAc) by sensitizing premalignant adenoma cells for apoptosis without affecting normal cells. We discuss these important findings, raise few points that deserve consideration, and may further contribute to the development of RAc-based combination therapies with improved efficacy. The authors clearly demonstrate a synergistic interaction between TRAIL, RAc and APC, which leads to the specific cell death of premalignant target cells. The study adds to the growing body of literature related to CRC chemoprevention, and provides solid data supporting a potentially selective approach for preventing CRC using RAc and TRAIL.

Pathobiology and Chemoprevention of Bladder Cancer

Science.gov (United States)

Tanaka, Takuji; Miyazawa, Katsuhito; Tsukamoto, Tetsuya; Kuno, Toshiya; Suzuki, Koji

2011-01-01

Our understanding of the pathogenesis of bladder cancer has improved considerably over the past decade. Translating these novel pathobiological discoveries into therapies, prevention, or strategies to manage patients who are suspected to have or who have been diagnosed with bladder cancer is the ultimate goal. In particular, the chemoprevention of bladder cancer development is important, since urothelial cancer frequently recurs, even if the primary cancer is completely removed. The numerous alterations of both oncogenes and tumor suppressor genes that have been implicated in bladder carcinogenesis represent novel targets for therapy and prevention. In addition, knowledge about these genetic alterations will help provide a better understanding of the biological significance of preneoplastic lesions of bladder cancer. Animal models for investigating bladder cancer development and prevention can also be developed based on these alterations. This paper summarizes the results of recent preclinical and clinical chemoprevention studies and discusses screening for bladder cancer. PMID:21941546

Combination Chemoprevention with Grape Antioxidants

OpenAIRE

Singh, Chandra K.; Siddiqui, Imtiaz A.; El-Abd, Sabah; Mukhtar, Hasan; Ahmad, Nihal

2016-01-01

Antioxidant ingredients present in grape have been extensively investigated for their cancer chemopreventive effects. However, much of the work has been done on individual ingredients, especially focusing on resveratrol and quercetin. Phytochemically, whole grape represents a combination of numerous phytonutrients. Limited research has been done on the possible synergistic/additive/antagonistic interactions among the grape constituents. Among these phytochemical constituents of grapes, resver...

Resveratrol: Chemoprevention with red wine

OpenAIRE

Arısan, Elif Damla; Palavan-Ünsal, Narçin

2007-01-01

According to epidemiological studies, western diet has disadvantages because of cancer prevalence more than Mediterranean or Asia people who consume more vegetables and fruits. Resveratrol (trans-3,4,5-trihydroxystilbene) which is highly found in grapes, berries has received attention for its potential chemopreventive and antitumor effects in experimental systems. Because of high resveratrol content, researchers noted that red wine has multidimensional benefits for ...

A Review of Promising Natural Chemopreventive Agents for Head and Neck Cancer.

Science.gov (United States)

Crooker, Kyle; Aliani, Rana; Ananth, Megha; Arnold, Levi; Anant, Shrikant; Thomas, Sufi Mary

2018-03-30

Head and neck squamous cell carcinoma (HNSCC) accounts for 300,000 deaths per year worldwide and overall survival rates have shown little improvement over the past three decades. Current treatment methods including surgery, chemotherapy, and radiotherapy leave patients with secondary morbidities. Thus, treatment of HNSCC may benefit from exploration of natural compounds as chemopreventive agents. With excellent safety profiles, reduced toxicities, antioxidant properties, and general acceptance for use as dietary supplements, natural compounds are viewed as a desirable area of investigation for chemoprevention. Though most of the field is early in development, numerous studies display the potential utility of natural compounds against HNSCC. These compounds face additional challenges such as low bioavailability for systemic delivery, potential toxicities when consumed in pharmacological doses, and acquired resistance. However, novel delivery vehicles and synthetic analogs have shown overcome some of these challenges. This review covers eleven promising natural compounds in the chemoprevention of HNSCC including vitamin A, curcumin, isothiocyanate, green tea, luteolin, resveratrol, genistein, lycopene, bitter melon, withaferin A, and guggulsterone. The review discusses the therapeutic potential and associated challenges of these agents in the chemopreventive efforts against HNSCC. Copyright ©2018, American Association for Cancer Research.

Cancer chemoprevention through dietary flavonoids: what's limiting?

Science.gov (United States)

Amawi, Haneen; Ashby, Charles R; Tiwari, Amit K

2017-06-19

Flavonoids are polyphenols that are found in numerous edible plant species. Data obtained from preclinical and clinical studies suggest that specific flavonoids are chemo-preventive and cytotoxic against various cancers via a multitude of mechanisms. However, the clinical use of flavonoids is limited due to challenges associated with their effective use, including (1) the isolation and purification of flavonoids from their natural resources; (2) demonstration of the effects of flavonoids in reducing the risk of certain cancer, in tandem with the cost and time needed for epidemiological studies, and (3) numerous pharmacokinetic challenges (e.g., bioavailability, drug-drug interactions, and metabolic instability). Currently, numerous approaches are being used to surmount some of these challenges, thereby increasing the likelihood of flavonoids being used as chemo-preventive drugs in the clinic. In this review, we summarize the most important challenges and efforts that are being made to surmount these challenges.

Epigenetic Regulation by Sulforaphane: Opportunities for Breast and Prostate Cancer Chemoprevention.

Science.gov (United States)

Atwell, Lauren L; Beaver, Laura M; Shannon, Jackilen; Williams, David E; Dashwood, Roderick H; Ho, Emily

2015-04-01

Sulforaphane (SFN) is a phytochemical derived from cruciferous vegetables that has multiple molecular targets and anti-cancer properties. Researchers have demonstrated several chemopreventive benefits of SFN consumption, such as reductions in tumor growth, increases in cancer cell apoptosis, and disruption of signaling within tumor microenvironments both in vitro and in vivo . Emerging evidence indicates that SFN exerts several of its chemopreventive effects by altering epigenetic mechanisms. This review summarizes evidence of the impact of SFN on epigenetic events and how they relate to the chemopreventive effects of SFN observed in preclinical and clinical studies of breast and prostate cancers. Specific areas of focus include the role of SFN in the regulation of cell cycle, apoptosis, inflammation, antioxidant defense, and cancer cell signaling and their relationships to epigenetic mechanisms. Finally, remaining challenges and research needs for translating mechanistic work with SFN into human studies and clinical intervention trials are discussed.

Chemoprevention of hormone-dependent prostate cancer in the Wistar-Unilever rat.

Science.gov (United States)

McCormick, D L; Rao, K V

1999-01-01

The high incidence and long latent period of prostate cancer make it an ideal target for chemoprevention. We have evaluated a series of agents for chemopreventive efficacy using a model in which hormone-dependent prostate cancers are induced in the Wistar-Unilever (WU) rat by sequential treatment with antiandrogen (cyproterone acetate), androgen (testosterone propionate), and direct-acting chemical carcinogen (N-methyl-N-nitrosourea), followed by chronic androgen stimulation (testosterone). This regimen reproducibly induces prostate cancers in high incidence, with no gross toxicity and a low incidence of neoplasia in the seminal vesicle and other non-target tissues. Dehydroepiandrosterone (DHEA) and 9-cis-retinoic acid (9-cis-RA) are the most active agents identified to date. DHEA inhibits prostate cancer induction both when chronic administration is begun prior to carcinogen exposure, and when administration is delayed until preneoplastic prostate lesions are present. 9-cis-RA is the most potent inhibitor of prostate carcinogenesis identified; a study to determine the efficacy of delayed administration of 9-cis-RA is in progress. Liarozole fumarate confers modest protection against prostate carcinogenesis, while N-(4-hydroxyphenyl)retinamide (fenretinide), alpha-difluoromethylornithine, oltipraz, DL-alpha-tocopherol acetate (vitamin E), and L-selenomethionine are inactive. Chemoprevention efficacy evaluations in the WU rat will support the identification of agents that merit study for prostate cancer chemoprevention in humans.

Evaluation of Antioxidant, Anti-cholinesterase, and Anti-inflammatory Effects of Culinary Mushroom Pleurotus pulmonarius.

Science.gov (United States)

Nguyen, Trung Kien; Im, Kyung Hoan; Choi, Jaehyuk; Shin, Pyung Gyun; Lee, Tae Soo

2016-12-01

Culinary mushroom Pleurotus pulmonarius has been popular in Asian countries. In this study, the anti-oxidant, cholinesterase, and inflammation inhibitory activities of methanol extract (ME) of fruiting bodies of P. pulmonarius were evaluted. The 1,1-diphenyl-2-picryl-hydrazy free radical scavenging activity of ME at 2.0 mg/mL was comparable to that of butylated hydroxytoluene, the standard reference. The ME exhibited significantly higher hydroxyl radical scavenging activity than butylated hydroxytoluene. ME showed slightly lower but moderate inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase than galantamine, a standard AChE inhibitor. It also exhibited protective effect against cytotoxicity to PC-12 cells induced by glutamate (10~100 µg/mL), inhibitory effect on nitric oxide (NO) production and inducible nitric oxide synthase protein expression in lipopolysaccharide-stimulated RAW 264.7 macrophages, and carrageenan-induced paw edema in a rat model. High-performance liquid chromatography analysis revealed the ME of P. pulmonarius contained at least 10 phenolic compounds and some of them were identified by the comparison with known standard phenolics. Taken together, our results demonstrate that fruiting bodies of P. pulmonarius possess antioxidant, anti-cholinesterase, and inflammation inhibitory activities.

Chemoprevention of prostate cancer: Natural compounds, antiandrogens, and antioxidants - In vivo evidence

Directory of Open Access Journals (Sweden)

Nur Özten-Kandas

2011-01-01

Full Text Available Prostate cancer is the leading non-skin malignancy detected in US males and the second cause of death due to male cancer, in the US. Interventions with drugs or diet supplements that slow down the growth and progression of prostate cancer are potentially very effective in reducing the burden of prostate cancer, particularly if these treatments also prevent the de novo development of new prostatic malignancies. Challenges to identify efficacious agents and develop them for chemopreventive application in men at risk for prostate cancer have included uncertainty about which preclinical models have the ability to predict efficacy in men and lack of consensus about which early phase clinical trial designs are the most appropriate and cost-effective to test promising agents. Efficacy studies in animal models have identified several agents with potential chemopreventive activity against prostate cancer, but few of these findings have been translated into clinical trials. This article identifies some of the major issues associated with prostate cancer chemoprevention research and summarizes the most significant current results from animal efficacy studies and human clinical prevention trials. This summary focuses on: (1 Naturally occurring agents and compounds derived from such agents, including green tea and its constituents, silibinin and milk thistle, and genistein and soy, (2 chemoprevention drugs including agents interfering with androgen action, and (3 antioxidants such as selenium, vitamin E, and lycopene. The general lack of activity of antioxidants is discussed, followed by considerations about translation of preclinical chemoprevention efficacy data, focusing on dose, form, bioavailability, and timing of administration of the agent, as well as discussion of study design of clinical trials and the predictive ability of preclinical models.

Linear free energy relationships in heterogeneous catalysis--13. The dehydration of aliphatic alcohols over silica-alumina. [N-butyl alcohol, sec. -butyl or isopropyl alcohol, tert. -butyl alcolol

Energy Technology Data Exchange (ETDEWEB)

Take, J; Matsumoto, T; Yoneda, Y

1978-01-01

The dehydration of n-butyl alcohol at 120/sup 0/-166/sup 0/C, sec.-butyl or isopropyl alcohol at 100/sup 0/-145/sup 0/C, and tert.-butyl alcohol at 54/sup 0/-80/sup 0/C, over silica/alumina catalyst was zero order in alcohol at 0.01-0.1 atm, and the activation energies were 35.3, 31.7, 32.0, and 29.9 kcal/mol, respectively. The zero-order rate constants were mainly affected by the activation energies since the preexponential factors varied little except for tert.-butyl alcohol. A linear relationship was found between the activation energy or the logarithm of the zero-order rate constant and the heterolytic bond dissociation energy for the carbon-oxygen bond in alcohols D(R/sup +/OH/sup -/). The activation energy increased and the rate constant decreased with increasing D(R/sup +/OH/sup -/). The results indicate that dehydration is E1 over this catalyst, but a similar correlation was observed based on published data for dehydration over alumina, which follows an E2 mechanism, indicating that heterolytic cleavage of the C-O bond is rate-determining in both mechanisms.

Targeting Chemoprevention of Colorectal Cancer to Those Who Are Likely to Respond

OpenAIRE

Stockbrugger, Reinhold W.

2010-01-01

In the past four decades, chemoprevention of colorectal cancer (CRC) has been the subject of many epidemiologic and intervention trials of naturally occurring or pharmacologic agents. Recently, the positioning of cyclooxygenase 2 inhibitors as a viable option in this context was a major breakthrough; however, it was hampered by adverse cardiovascular events. This review questions whether chemopreventive measures for CRC are ready to be used in mass or individual applications, standing alone o...

Community analysis of preservative-treated southern pine (Pinus spp.) using terminal restriction fragment length polymorphism (T-RFLP) analysis

Science.gov (United States)

Grant T. Kirker; M. Lynn Prewitt; Walter J. Diehl; Susan V. Diehl

2012-01-01

The effects of wood preservatives on the bacterial community in southern yellow pine were assessed by the molecular method ‘terminal restriction fragment length polymorphism’ (T-RFLP). Stakes, treated with 0.25 % and 0.37 % ammoniacal copper quat (ACQ-C), 0.1 % and 0.25 % chlorothalonil (CTN), 0.1 % and 0.25 % CTN with 2 % butylated hydroxytoluene (BHT), and 2 % BHT...

Use of nonsteroidal antiinflamatory drugs for chemoprevention of colon cancer

Directory of Open Access Journals (Sweden)

Milić Aleksandra

2013-01-01

Full Text Available Colorectal cancer is in the third most frequent cancer among malignant tumors of both sexes in developed countries. It is predominantly a disease of older persons and occurs mostly after the age of 60. Although the etiology of colon cancer is unknown, it is assumed to arise as a result of unclear and complex interactions between genetic and environmental factors. The main element in the etiology of colorectal cancer is the process of genetic changes in epithelial cells of colon mucosa. It is believed that specific epidemiological factors such as stress, hypoxia, reduced intake of glucose and other nutrients, a hereditary predisposition to mutagenic effects, the meat in the diet, bile acids, reduced intake of minerals and vitamins as well as changes in pH of feces lead to initiation of the process of carcinogenesis in mucosa of the colon. Cancer chemoprevention is defined as the use of chemical agents in order to block, prevent or delay the reversal development or progress of cancer. It is believed that chemoprevention is a key component of cancer control, and numerous studies indicate potential role of NSAIDs in chemoprevention of colon cancer.

Using Breast Cancer Risk Associated Polymorphisms to Identify Women for Breast Cancer Chemoprevention.

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Elad Ziv

Full Text Available Breast cancer can be prevented with selective estrogen receptor modifiers (SERMs and aromatase inhibitors (AIs. The US Preventive Services Task Force recommends that women with a 5-year breast cancer risk ≥3% consider chemoprevention for breast cancer. More than 70 single nucleotide polymorphisms (SNPs have been associated with breast cancer. We sought to determine how to best integrate risk information from SNPs with other risk factors to risk stratify women for chemoprevention.We used the risk distribution among women ages 35-69 estimated by the Breast Cancer Surveillance Consortium (BCSC risk model. We modeled the effect of adding 70 SNPs to the BCSC model and examined how this would affect how many women are reclassified above and below the threshold for chemoprevention.We found that most of the benefit of SNP testing a population is achieved by testing a modest fraction of the population. For example, if women with a 5-year BCSC risk of >2.0% are tested (~21% of all women, ~75% of the benefit of testing all women (shifting women above or below 3% 5-year risk would be derived. If women with a 5-year risk of >1.5% are tested (~36% of all women, ~90% of the benefit of testing all women would be derived.SNP testing is effective for reclassification of women for chemoprevention, but is unlikely to reclassify women with <1.5% 5-year risk. These results can be used to implement an efficient two-step testing approach to identify high risk women who may benefit from chemoprevention.

In vitro evaluation of the antioxidant potential, phenolic and flavonoid contents of the stem bark ethanol extract of Anogeissus leiocarpus.

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Olugbami, J O; Gbadegesin, M A; Odunola, O A

2014-09-01

Plant-derived antioxidants with free radical scavenging activities can be relevant as chemopreventive agents against the numerous diseases associated with free radicals and reactive oxygen species. Some phytoconstituents possess antioxidant activities in biological systems. On this basis, we evaluated the antioxidant potential, and determined the total phenolic and flavonoid contents of the e thanol e xtract of the s tem bark of A nogeissus l eiocarpus [ EESAL ]. Antioxidant assays carried out include: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, phosphomolybdate, β-carotene bleaching, ferric reducing, and hydroxyl radical scavenging activities. Results of DPPH assay showed no significant difference ( p antioxidant capacity of 190.00 ± 70.53 µg butylated hydroxytoluene equivalents [BHTE]/mg dry extract, while β-carotene bleaching assay gave percent antioxidant activities of both EESAL and BHT as 81.46±1.62 and 80.90±1.39 respectively. Ferric reducing abilities of both EESAL and ascorbic acid increased in a concentration-dependent manner with EESAL displaying a significantly ( p concentration with no significant difference at the highest concentration. Total phenolic and flavonoid contents of EESAL were obtained as 608.10 ± 2.12 µg GAE/mg and 78.96 ± 3.37 µg QE/mg respectively. Taken together, the free radical scavenging and antioxidant activity of EESAL is likely due to its high phenolic content with complementary effects of the flavonoid components.

Chemoprevention of Colorectal Cancer by Artocarpin, a Dietary Phytochemical from Artocarpus heterophyllus.

Science.gov (United States)

Sun, Guochuan; Zheng, Zongping; Lee, Mee-Hyun; Xu, Yijuan; Kang, Soouk; Dong, Zigang; Wang, Mingfu; Gu, Zhennan; Li, Haitao; Chen, Wei

2017-05-03

Artocarpus heterophyllus is an evergreen tree distributed in tropical regions, and its fruit (jackfruit) is well-known as the world's largest tree-borne fruit. Although A. heterophyllus has been widely used in folk medicines against inflammation, its potential in cancer chemoprevention remains unclear. Herein we identified artocarpin from A. heterophyllus as a promising colorectal cancer chemopreventive agent by targeting Akt kinase. Phenotypically, artocarpin exhibited selective cytotoxicity against human colon cancer cells. Artocarpin impaired the anchorage-independent growth capability, suppressed colon cancer cell growth, and induced a G1 phase cell cycle arrest which was followed by apoptotic as well as autophagic cell death. Mechanistic studies revealed that artocarpin directly targeted Akt 1 and 2 kinase activity evidenced by in vitro kinase assay, ex vivo binding assay as well as Akt downstream cellular signal transduction. Importantly, oral administration of artocarpin attenuated colitis-associated colorectal tumorigenesis in mice. Taken together, artocarpin, a bioactive component of A. heterophyllus, might merit investigation as a potential colorectal cancer chemopreventive agent.

Gamma-radiation effect on thermal ageing of butyl rubber compounds

Energy Technology Data Exchange (ETDEWEB)

Scagliusi, Sandra R.; Cardoso, Elizabeth C.L.; Lugao, Ademar B., E-mail: srscagliusi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Butyl rubber has a comprehensive use in sealing systems, especially in tires inner tubes, due to their low permeability to gases. So, it is required that butyl rubber compounds show a better performance, more and more. Butyl rubber is provided with excellent mechanical properties and oxidation resistance. Besides showing these properties, radiation exposures impart modifications in physical-chemical and morphological properties on butyl rubber materials. When exposed to gamma-radiation, rubbers suffer changes in their mechanical and physical properties, caused by material degradation. The major radiation effect in butyl rubbers is chain scission; besides, ageing promotes too the same effect with further build-up of free radicals. This work aims to the study of gamma-radiation in physical-chemical properties of butyl rubber subjected to thermal ageing. Doses used herein were: 25 kGy, 50 kGy, 100 kGy, 150 kGy and 200 KGy. Samples were evaluated before and after ageing according to traditional essays, such as: hardness, tensile strength and elongation at break. From accomplished assessments it is possible to affirm that at doses higher than 50 kGy it was observed a sharp decreasing in butyl rubber physical-chemical properties, before and after exposure to ageing. (author)

Gamma-radiation effect on thermal ageing of butyl rubber compounds

International Nuclear Information System (INIS)

Scagliusi, Sandra R.; Cardoso, Elizabeth C.L.; Lugao, Ademar B.

2015-01-01

Butyl rubber has a comprehensive use in sealing systems, especially in tires inner tubes, due to their low permeability to gases. So, it is required that butyl rubber compounds show a better performance, more and more. Butyl rubber is provided with excellent mechanical properties and oxidation resistance. Besides showing these properties, radiation exposures impart modifications in physical-chemical and morphological properties on butyl rubber materials. When exposed to gamma-radiation, rubbers suffer changes in their mechanical and physical properties, caused by material degradation. The major radiation effect in butyl rubbers is chain scission; besides, ageing promotes too the same effect with further build-up of free radicals. This work aims to the study of gamma-radiation in physical-chemical properties of butyl rubber subjected to thermal ageing. Doses used herein were: 25 kGy, 50 kGy, 100 kGy, 150 kGy and 200 KGy. Samples were evaluated before and after ageing according to traditional essays, such as: hardness, tensile strength and elongation at break. From accomplished assessments it is possible to affirm that at doses higher than 50 kGy it was observed a sharp decreasing in butyl rubber physical-chemical properties, before and after exposure to ageing. (author)

Organic Semiconductors and Conductors with tert-Butyl Substituents

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Toshiki Higashino

2012-08-01

Full Text Available Tetrathiafulvalene (TTF, pentacene, and quarterthiophene with tert-butyl substituents are synthesized, and the crystal structures and the transistor properties are investigated. The tetracyanoquinodimethane (TCNQ complex of tert-butyl TTF constructs highly one-dimensional segregated columns with tetragonal crystal symmetry.

Targeting Chemoprevention of Colorectal Cancer to Those Who Are Likely to Respond.

Science.gov (United States)

Stockbrugger, Reinhold W

2010-01-01

In the past four decades, chemoprevention of colorectal cancer (CRC) has been the subject of many epidemiologic and intervention trials of naturally occurring or pharmacologic agents. Recently, the positioning of cyclooxygenase 2 inhibitors as a viable option in this context was a major breakthrough; however, it was hampered by adverse cardiovascular events. This review questions whether chemopreventive measures for CRC are ready to be used in mass or individual applications, standing alone or in combination with other CRC-preventive measures. It also discusses steps that may be undertaken to explore this field further.

Sulforaphane (SFN: An Isothiocyanate in a Cancer Chemoprevention Paradigm

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Mohammad Fahad Ullah

2015-07-01

Full Text Available The International Agency for Research on Cancer (IARC in its latest World Cancer Report (2014 has projected the increase in the global cancer burden from 14 million (2012 to 22 million incidence annually within the next two decades. Such statistics warrant a collaborative engagement of conventional and complementary and alternative therapies to contain and manage cancer. In recent years, there has been a shift in the cancer chemoprevention paradigm with a significant focus turning towards bioactive components of human diets for their anticancer properties. Since diet is an integral part of lifestyle and given that an estimated one third of human cancers are believed to be preventable though appropriate lifestyle modification including dietary habits, the current shift in the conventional paradigm assumes significance. Several epidemiological studies have indicated that consumption of broccoli is associated with a lower risk of cancer incidence including breast, prostate, lung, stomach and colon cancer. The edible plant belonging to the family of cruciferae such as broccoli is a rich source of glucoraphanin, a precursor of isothiocyanate sulforaphane which is considered to be a potent anti-cancer agent. Plant-based dietary agents such as sulforaphane mimic chemotherapeutic drugs such as vorinostat, possessing histone deacetylase inhibition activity. Evidence from epidemiological and experimental studies have emerged, enhancing the clinical plausibility and translational value of sulforaphane in cancer chemoprevention. The present review provides the current understanding of the cancer chemopreventive pharmacology of sulforaphane towards its potential as an anticancer agent.

Preclinical renal cancer chemopreventive efficacy of geraniol by modulation of multiple molecular pathways

International Nuclear Information System (INIS)

Ahmad, Shiekh Tanveer; Arjumand, Wani; Seth, Amlesh; Nafees, Sana; Rashid, Summya; Ali, Nemat; Sultana, Sarwat

2011-01-01

Graphical abstract: Diagrammatic presentation of the hypothesis of the article in a concise manner. It reveals the chemopreventive efficacy of GOH possibly through the modulation of multiple molecular targets. GOH inhibits ROS generation, NFκB and PCNA expression thereby abrogating inflammation and proliferation of tubular cells of kidney. Whereas, GOH induces effector caspase-3 expression both through mitochondrial signalling pathway and death receptor signalling pathway. Highlights: → Geraniol modulates renal carcinogenesis in Wistar rats. → It abrogates Fe-NTA induced oxidative stress, inflammation and hyperproliferation. → Promotes apoptosis via induction of both mitochondrial and death receptor pathway. → Thus, inhibits renal carcinogenesis by modulating multiple molecular targets. -- Abstract: In the present study, we have evaluated the chemopreventive potential of geraniol (GOH), an acyclic monoterpene alcohol against ferric nitrilotriacetate (Fe-NTA) induced renal oxidative stress and carcinogenesis in Wistar rats. Chronic treatment of Fe-NTA induced oxidative stress, inflammation and cellular proliferation in Wistar rats. The chemopreventive efficacy of GOH was studied in terms of xenobiotic metabolizing enzyme activities, LPO, redox status, serum toxicity markers and the expression of putative nephrotoxicity biomarker Kim-1, tumor suppressor gene P53, inflammation, cell proliferation and apoptosis related genes in the kidney tissue. Oral administration of GOH at doses of 100 and 200 mg/kg b wt effectively suppressed renal oxidative stress and tumor incidence. Chemopreventive effects of GOH were associated with upregulation of xenobiotic metabolizing enzyme activities and down regulation of serum toxicity markers. GOH was able to down regulate expression of Kim-1, NFκB, PCNA, P53 along with induction of apoptosis. However, higher dose of GOH was more effective in modulating these multiple molecular targets both at transcriptional and protein

Effects of hydroxylated benzaldehyde derivatives on radiation-induced reactions involving various organic radicals

Science.gov (United States)

Ksendzova, G. A.; Samovich, S. N.; Sorokin, V. L.; Shadyro, O. I.

2018-05-01

In the present paper, the effects of hydroxylated benzaldehyde derivatives and gossypol - the known natural occurring compound - on formation of decomposition products resulting from radiolysis of ethanol and hexane in deaerated and oxygenated solutions were studied. The obtained data enabled the authors to make conclusions about the effects produced by the structure of the compounds under study on their reactivity towards oxygen- and carbon-centered radicals. It has been found that 2,3-dihydroxybenzaldehyde, 4,6-di-tert-butyl-2,3-dihydroxybenzaldehyde and 4,6-di-tert-butyl-3-(1,3-dioxane-2-yl)-1,2-dihydroxybenzene are not inferior in efficiency to butylated hydroxytoluene - the industrial antioxidant - as regards suppression of the radiation-induced oxidation processes occurring in hexane. The derivatives of hydroxylated benzaldehydes were shown to have a significant influence on radiation-induced reactions involving α-hydroxyalkyl radicals.

Chemopreventive and Anticancer Activities of Allium victorialis var. platyphyllum Extracts.

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Kim, Hyun-Jeong; Park, Min Jeong; Park, Hee-Juhn; Chung, Won-Yoon; Kim, Ki-Rim; Park, Kwang-Kyun

2014-09-01

Allium victorialis var. platyphyllum is an edible perennial herb and has been used as a vegetable or as a Korean traditional medicine. Allium species have received much attention owing to their diverse pharmacological properties, including antioxidative, anti-inflammatory, and anticancer activities. However, A. victorialis var. platyphyllum needs more study. The chemopreventive potential of A. victorialis var. platyphyllum methanol extracts was examined by measuring 12-O-tetra-decanoylphorbol 13-acetate (TPA)-induced superoxide anion production in the differentiated HL-60 cells, TPA-induced mouse ear edema, and Ames/Salmonella mutagenicity. The apoptosis-inducing capabilities of the extracts were evaluated by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, 4',6-diamidino-2-phenylindole staining, and the DNA fragmentation assay in human colon cancer HT-29 cells. Antimetastatic activities of the extracts were also investigated in an experimental mouse lung metastasis model. The methanol extracts of A. victorialis var. platyphyllum rhizome (AVP-R) and A. victorialis var. platyphyllum stem (AVP-S) dose-dependently inhibited the TPA-induced generation of superoxide anion in HL-60 cells and TPA-induced ear edema in mice, as well as 7,12-dimethylbenz[a]anthracene (DMBA) and tert-butyl hydroperoxide (t-BOOH) -induced bacterial mutagenesis. AVP-R and AVP-S reduced cell viability in a dose-related manner and induced apoptotic morphological changes and internucleosomal DNA fragmentation in HT-29 cells. In the experimental mouse lung metastasis model, the formation of tumor nodules in lung tissue was significantly inhibited by the treatment of the extracts. AVP-R and AVP-S possess antioxidative, anti-inflammatory, antimutagenic, proapoptotic, and antimetastatic activities. Therefore, these extracts can serve as a beneficial supplement for the prevention and treatment of cancer.

Nutraceuticals for prostate cancer chemoprevention: from molecular mechanisms to clinical application.

Science.gov (United States)

Wang, Zhijun; Fan, Jeffery; Liu, Mandy; Yeung, Steven; Chang, Andy; Chow, Moses S S; Pon, Doreen; Huang, Ying

2013-12-01

Nutraceutical is a food, or part of a food, used for the prevention and/or treatment of diseases. A number of nutraceuticals serve as candidates for development of prostate cancer chemopreventive agents because of promising epidemiological, preclinical and pilot clinical findings. Their mechanisms of action may involve an ability to target multiple molecular pathways in carcinogenesis without eliciting toxic side effects. This review provides an overview of several nutraceuticals, including green tea polyphenol, omega-3 fatty acids, vitamin D, lycopene, genistein, quercetin, resveratrol and sulforaphane, for the clinical relevance to chemoprevention of prostate cancer. Their mechanisms of action on regulating key processes of carcinogenesis are also discussed. For each of these agents, a brief summary of completed or currently ongoing clinical trials related to the chemopreventive efficacy on prostate cancer is given. Even though a few clinical trials have been conducted, review of these results indicate that further studies are required to confirm the clinical efficacy and safety, and to provide a guidance on how to use nutraceuticals for optimal effect. Future cancer prevention clinical trials for the nutraceuticals should recruit men with an increased risk of prostate cancer.

Butylated caffeic acid: An efficient novel antioxidant

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G. Shi

2017-09-01

Full Text Available A novel antioxidant, butylated caffeic acid (BCA was rationally designed by adding a tert-butyl group to caffeic acid, which was synthesized at a high yield (36.2% from 2-methoxy-4-methylphenol by a four-step reaction including Friedel-Crafts alkylation, bromine oxidation, ether bond hydrolysis and Knoevenagel condensation. Its antioxidant capacity was much stronger than common commercial antioxidant tert-butyl hydroquinone (TBHQ and its mother compound, caffeic acid, in both rancimat and deep frying tests. When investigated via the DPPH method, the antioxidant capacity of BCA was almost equal to TBHQ, but lower than caffeic acid. BCA could be a potentially strong antioxidant, especially for food processing at high temperatures such as deep frying and baking.

Butylated caffeic acid: An efficient novel antioxidant

International Nuclear Information System (INIS)

Shi, G.; Liao, X.; Olajide, T.M.; Liu, J.; Jiang, X.; Weng, X.

2017-01-01

A novel antioxidant, butylated caffeic acid (BCA) was rationally designed by adding a tert-butyl group to caffeic acid, which was synthesized at a high yield (36.2%) from 2-methoxy-4-methylphenol (1) by a four-step reaction including Friedel-Crafts alkylation, bromine oxidation, ether bond hydrolysis and Knoevenagel condensation. Its antioxidant capacity was much stronger than common commercial antioxidant tert-butyl hydroquinone (TBHQ) and its mother compound, caffeic acid, in both rancimat and deep frying tests. When investigated via the DPPH method, the antioxidant capacity of BCA was almost equal to TBHQ, but lower than caffeic acid. BCA could be a potentially strong antioxidant, especially for food processing at high temperatures such as deep frying and baking. [es

Recovering/recycling of butyl and halogenated butyl rubber via ionizing radiation; Recuperacao/reciclagem de compostos de borrachas butilica e halobutilica por meio de radiacao ionizante

Energy Technology Data Exchange (ETDEWEB)

Martin, Sandra Regina Scagliusi

2013-07-01

Polymeric materials (plastics and rubbers) attain a continuous and raising proportion of urban and industrial scraps discarded in landfills; their impact on environment are more and more concerning. The implementation of new technologies in order to reduce impacts of plastic waste on the environment, at an effective cost, proved to be a great problem, due to inherent complexity for polymers re-using. Ionizing radiation is capable to modify structure and properties of polymeric material. Butyl and halobutyl rubbers have been used within a comprehensive scale, applications such as tires spare parts and diverse artifacts. The major high energy photon effect, as gamma-rays in butyl and halo butyl rubbers consists in free-radicals generation along changes in mechanical properties.This work aims to the development of controlled degradation processes (devulcanization) of butyl and halo butyl (chlorine and bromine) rubbers, in order to characterize their availability for transformation and modification of properties. Experimental results obtained showed that butyl and halobutyl rubbers,irradiated at 25 kGy and further sheared, are able to be used as an initial point for mixtures with pristine. (author)

Recycling of Gamma Irradiated Inner Tubes in Butyl Based Rubber Compound

International Nuclear Information System (INIS)

Karaagac, B.

2006-01-01

Crosslinked elastomeric materials, such as tyres are of great challenge concerning the environmental and ecological reasons. Ionizing radiation seems to offer unique opportunities to tackle the problem of recycling of polymers and rubbers on account of its ability to cause chain scission and/or cross-linking of polymeric materials. There is only limited amount of work reported on the irradiation-induced degradation of rubbers. Unlike the majority of the elastomers with high levels of unsaturation, butyl rubber exhibits significant degradation by ionizing radiation action. In this study, recycling of gamma irradiated inner tubes made of butyl rubber in butyl based rubber compounds was studied. Used inner tubes were irradiated with gamma rays in air at 100 and 120 kGy absorbed doses. The compatibility of irradiated inner tubes with virgin butyl rubber was first investigated. Gamma irradiated inner tube wastes were replaced with butyl rubber up to 15 phr in the compound recipe. Similar recipes were also prepared by using the same quantity of commercial butyl rubber crumbs devulcanized by conventional methods. The rheological and mechanical properties and carbon black dispersion degree for both types of compounds prepared by using inner tubes scraps and commercial butyl crumbs were measured and were compared to the values of virgin butyl rubber compound. It is well known that mechanical properties are deteriorated when rubber crumb is added to the virgin compound. It was observed that the decrease in the mechanical properties was much lower for the compounds prepared from the tubes irradiated at 120 kGy than irradiated at 100 kGy. The better mechanical properties were obtained for the compounds prepared by recycling of irradiated inner tubes at 120 kGy than the compounds prepared by using commercial butyl crumbs. Almost similar carbon black distributions were observed for the all compounds studied. It has been concluded that gamma irradiated inner tubes are compatible

NMR analysis of t-butyl-catalyzed deuterium exchange at unactivated arene localities.

Science.gov (United States)

Stack, Douglas E; Eastman, Rachel

2016-10-01

Regioselective labelling of arene rings via electrophilic exchange is often dictated by the electronic environment caused by substituents present on the aromatic system. Previously, we observed the presence of a t-butyl group, either covalently bond or added as an external reagent, could impart deuterium exchange to the unactivated, C1-position of estrone. Here, we provide nuclear magnetic resonance analysis of this exchange in a solvent system composed of 50:50 trifluoroacetic acid and D 2 O with either 2-t-butylestrone or estrone in the presence of t-butyl alcohol has shed insights into the mechanism of this t-butyl-catalyzed exchange. Fast exchange of the t-butyl group concurrent with the gradual reduction of the H1 proton signal in both systems suggest a mechanism involving ipso attack of the t-butyl position by deuterium. The reversible addition/elimination of the t-butyl group activates the H1 proton towards exchange by a mechanism of t-butyl incorporation, H1 activation and exchange, followed by eventual t-butyl elimination. Density functional calculations are consistent with the observation of fast t-butyl exchange concurrent with slower H1 exchange. The σ-complex resulting from ipso attack of deuterium at the t-butyl carbon was 6.6 kcal/mol lower in energy than that of the σ-complex resulting from deuterium attack at C1. A better understanding of the t-butyl-catalyzed exchange could help in the design of labelling recipes for other phenolic metabolites. Copyright © 2016 The Authors. Journal of Labelled Compounds and Radiopharmaceuticals published by John Wiley & Sons, Ltd.

Sensory analysis of dairy products irradiated with cobalt-60 at -78 degrees C

International Nuclear Information System (INIS)

Hashisaka, A.E.; Einstein, M.A.; Rasco, B.A.; Hungate, F.P.; Dong, F.M.

1990-01-01

Sensory evaluations by healthy individuals were conducted on cobalt-60 irradiated retail dairy products which were to be incorporated into the low microbial diets of immunosuppressed patients. Irradiation (40 kGy at -78 degrees C) caused little change in product color or texture, but generally there was a decrease in overall acceptability and an increase in off-flavor and aftertaste. Modified atmosphere packaging (nitrogen, helium, or air) or antioxidant addition (ascorbyl palmitate or a combination of butylated hydroxyanisole and butylated hydroxytoluene) prior to irradiation were effective in preserving specific sensory attributes, which in some cases resulted in improved overall acceptability (helium packed peppermint ice cream; ascorbyl palmitate treated strawberry yogurt bars) when compared to untreated irradiated products

Phytochemicals: Extraction, Isolation, and Identification of Bioactive Compounds from Plant Extracts

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Ammar Altemimi

2017-09-01

Full Text Available There are concerns about using synthetic phenolic antioxidants such as butylated hydroxytoluene (BHT and butylated hydroxyanisole (BHA as food additives because of the reported negative effects on human health. Thus, a replacement of these synthetics by antioxidant extractions from various foods has been proposed. More than 8000 different phenolic compounds have been characterized; fruits and vegetables are the prime sources of natural antioxidants. In order to extract, measure, and identify bioactive compounds from a wide variety of fruits and vegetables, researchers use multiple techniques and methods. This review includes a brief description of a wide range of different assays. The antioxidant, antimicrobial, and anticancer properties of phenolic natural products from fruits and vegetables are also discussed.

Inducing PLA/starch compatibility through butyl-etherification of waxy and high amylose starch.

Science.gov (United States)

Wokadala, Obiro Cuthbert; Emmambux, Naushad Mohammad; Ray, Suprakas Sinha

2014-11-04

In this study, waxy and high amylose starches were modified through butyl-etherification to facilitate compatibility with polylactide (PLA). Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy and wettability tests showed that hydrophobic butyl-etherified waxy and high amylose starches were obtained with degree of substitution values of 2.0 and 2.1, respectively. Differential scanning calorimetry, tensile testing, and scanning electron microscopy (SEM) demonstrated improved PLA/starch compatibility for both waxy and high amylose starch after butyl-etherification. The PLA/butyl-etherified waxy and high amylose starch composite films had higher tensile strength and elongation at break compared to PLA/non-butyl-etherified composite films. The morphological study using SEM showed that PLA/butyl-etherified waxy starch composites had a more homogenous microstructure compared to PLA/butyl-etherified high amylose starch composites. Thermogravimetric analysis showed that PLA/starch composite thermal stability decreased with starch butyl-etherification for both waxy and high amylose starches. This study mainly demonstrates that PLA/starch compatibility can be improved through starch butyl-etherification. Copyright © 2014 Elsevier Ltd. All rights reserved.

Lung Cancer Chemopreventive Activity of Patulin Isolated from Penicillium vulpinum

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Aymeric Monteillier

2018-03-01

Full Text Available Lung cancer is the most lethal form of cancer in the world. Its development often involves an overactivation of the nuclear factor kappa B (NF-κB pathway, leading to increased cell proliferation, survival, mobility, and a decrease in apoptosis. Therefore, NF-κB inhibitors are actively sought after for both cancer chemoprevention and therapy, and fungi represent an interesting unexplored reservoir for such molecules. The aim of the present work was to find naturally occurring lung cancer chemopreventive compounds by investigating the metabolites of Penicillium vulpinum, a fungus that grows naturally on dung. Penicillium vulpinum was cultivated in Potato Dextrose Broth and extracted with ethyl acetate. Bioassay-guided fractionation of this extract was performed by measuring NF-κB activity using a HEK293 cell line transfected with an NF-κB-driven luciferase reporter gene. The mycotoxin patulin was identified as a nanomolar inhibitor of TNF-α-induced NF-κB activity. Immunocytochemistry and Western blot analyses revealed that its mechanism of action involved an inhibition of p65 nuclear translocation and was independent from the NF-κB inhibitor α (IκBα degradation process. Enhancing its interest in lung cancer chemoprevention, patulin also exhibited antiproliferative, proapoptotic, and antimigration effects on human lung adenocarcinoma cells through inhibition of the Wnt pathway.

Contribution to the study of uranyl salts in butyl phosphate solutions

International Nuclear Information System (INIS)

Coulon, A.

1965-06-01

A spectroscopic study in the normal infrared region and involving the following associations: tri-alkyl phosphates (tri-butyl, tri-ethyl, tri-methyl), uranyl salts (nitrate, chloride, acetate) has confirmed the existence of an interaction between the phosphoryl group and the uranium atom, as shown by a movement of absorption band for the valency P = 0 from ∼ 1270 cm -1 to ∼ 1180 cm -1 . A study of the preparation, analysis and spectroscopy of the solids obtained by the precipitation of uranyl salts by acid butyl phosphates has been carried out. By infrared spectrophotometry it has been shown that the tri-butyl and di-butyl phosphates are associated in non-polar diluents even before the uranium is introduced. The extraction of uranyl salts from acid aqueous solutions by a diluted mixture of tri-butyl and di-butyl phosphates proceeds by different mechanisms according to the nature of the ion (nitrate or chloride). (author) [fr

Oral chemoprevention with acetyl salicylic Acid, vitamin d and calcium reduces the risk of tobacco carcinogen-induced bladder tumors in mice

DEFF Research Database (Denmark)

Pommergaard, Hans-Christian; Burcharth, J; Rosenberg, J

2013-01-01

, and diet with chemoprevention (acetyl salicylic acid, 1-alpha 25(0H)2-vitamin D3 and calcium). There were significantly fewer tumors (0 (0-0) vs. 0 (0-2), p = .045) and fewer animals with tumors (0/20 vs. 5/20, p = .045) in the chemoprevention group compared with controls. Thus, chemoprevention diet...

Phyto-oestrogens and breast cancer chemoprevention

International Nuclear Information System (INIS)

Limer, Jane L; Speirs, Valerie

2004-01-01

Phytoestrogens are polyphenol compounds of plant origin that exhibit a structural similarity to the mammalian steroid hormone 17β-oestradiol. In Asian nations the staple consumption of phyto-oestrogen-rich foodstuffs correlates with a reduced incidence of breast cancer. Human dietary intervention trials have noted a direct relationship between phyto-oestrogen ingestion and a favourable hormonal profile associated with decreased breast cancer risk. However, these studies failed to ascertain the precise effect of dietary phyto-oestrogens on the proliferation of mammary tissue. Epidemiological and rodent studies crucially suggest that breast cancer chemoprevention by dietary phyto-oestrogen compounds is dependent on ingestion before puberty, when the mammary gland is relatively immature. Phyto-oestrogen supplements are commercially marketed for use by postmenopausal women as natural and safe alternatives to hormone replacement therapy. Of current concern is the effect of phyto-oestrogen compounds on the growth of pre-existing breast tumours. Data are contradictory, with cell culture studies reporting both the oestrogenic stimulation of oestrogen receptor-positive breast cancer cell lines and the antagonism of tamoxifen activity at physiological phyto-oestrogen concentrations. Conversely, phyto-oestrogen ingestion by rodents is associated with the development of less aggressive breast tumours with reduced metastatic potential. Despite the present ambiguity, current data do suggest a potential benefit from use of phyto-oestrogens in breast cancer chemoprevention and therapy. These aspects are discussed

The strategies to control prostate cancer by chemoprevention approaches

International Nuclear Information System (INIS)

Ting, Harold; Deep, Gagan; Agarwal, Chapla; Agarwal, Rajesh

2014-01-01

Prostate cancer (PCA) is the most commonly diagnosed cancer in men in the United States with growing worldwide incidence. Despite intensive investment in improving early detection, PCA often escapes timely detection and mortality remains high; this malignancy being the second highest cancer-associated mortality in American men. Collectively, health care costs of PCA results in an immense financial burden that is only expected to grow. Additionally, even in cases of successful treatment, PCA is associated with long-term and pervasive effects on patients. A proactive alternative to treat PCA is to prevent its occurrence and progression prior to symptomatic malignancy. This may serve to address the issue of burgeoning healthcare costs and increasing number of sufferers. One potential regimen in service of this alternative is PCA chemoprevention. Here, chemical compounds with cancer preventive efficacy are identified on the basis of their potential in a host of categories: their historical medicinal use, correlation with reduced risk in population studies, non-toxicity, their unique chemical properties, or their role in biological systems. PCA chemopreventive agents are drawn from multiple broad classes of chemicals, themselves further subdivided based on source or potential effect, with most derived from natural products. Many such compounds have shown efficacy, varying from inhibiting deregulated PCA cell signaling, proliferation, epithelial to mesenchymal transition (EMT), invasion, metastasis, tumor growth and angiogenesis and inducing apoptosis. Overall, these chemopreventive agents show great promise in PCA pre-clinical models, though additional work remains to be done in effectively translating these findings into clinical use

Prostate cancer chemoprevention in men of African descent: current state of the art and opportunities for future research.

Science.gov (United States)

Chornokur, Ganna; Kumar, Nagi B

2013-08-01

Prostate cancer is the most frequently diagnosed malignancy in men. However, African American/Black men are 60 % more likely to be diagnosed with and 2.4 times more likely to die from prostate cancer, compared to Non-Hispanic White men. Despite the increased burden of this malignancy, no evidence-based recommendation regarding prostate cancer screening exists for the high-risk population. Moreover, in addition to screening and detection, African American men may constitute a prime population for chemoprevention. Early detection and chemoprevention may thus represent an integral part of prostate cancer control in this population. Importantly, recent research has elucidated biological differences in the prostate tumors of African American compared to European American men. The latter may enable a more favorable response in African American men to specific chemopreventive agents that target relevant signal transduction pathways. Based on this evolving evidence, the aims of this review are threefold. First, we aim to summarize the biological differences that were reported in the prostate tumors of African American and European American men. Second, we will review the single- and multi-target chemopreventive agents placing specific emphasis on the pathways implicated in prostate carcinogenesis. And lastly, we will discuss the most promising nutraceutical chemopreventive compounds. Our review underscores the promise of chemoprevention in prostate cancer control, as well as provides justification for further investment in this filed to ultimately reduce prostate cancer morbidity and mortality in this high-risk population of African American men.

and triorganotin(IV) complexes of 2-tert-butyl-4-methyl phenol

Indian Academy of Sciences (India)

TECS

-2-Me-4) have been synthesized by the reactions of di-n-butyl and dimethyltin dichlorides and tri-n-butyltin(IV) chloride with 2-tert-butyl-4-methylphenol and triethylamine in tetrahydrofuran. The reaction of triphenyltin chloride with trimethylsilyl-2-t-butyl-4- methylphenoxide in the same solvent however, gives a complex of ...

Pomegranate-mediated chemoprevention of experimental hepatocarcinogenesis involves Nrf2-regulated antioxidant mechanisms

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Bishayee, Anupam; Bhatia, Deepak; Thoppil, Roslin J.; Darvesh, Altaf S.; Nevo, Eviatar; Lansky, Ephraim P.

2011-01-01

Hepatocellular carcinoma (HCC), one of the most prevalent and lethal cancers, has shown an alarming rise in the USA. Without effective therapy for HCC, novel chemopreventive strategies may effectively circumvent the current morbidity and mortality. Oxidative stress predisposes to hepatocarcinogenesis and is the major driving force of HCC. Pomegranate, an ancient fruit, is gaining tremendous attention due to its powerful antioxidant properties. Here, we examined mechanism-based chemopreventive potential of a pomegranate emulsion (PE) against dietary carcinogen diethylnitrosamine (DENA)-induced rat hepatocarcinogenesis that mimics human HCC. PE treatment (1 or 10 g/kg), started 4 weeks prior to the DENA challenge and continued for 18 weeks thereafter, showed striking chemopreventive activity demonstrated by reduced incidence, number, multiplicity, size and volume of hepatic nodules, precursors of HCC. Both doses of PE significantly attenuated the number and area of γ-glutamyl transpeptidase-positive hepatic foci compared with the DENA control. PE also attenuated DENA-induced hepatic lipid peroxidation and protein oxidation. Mechanistic studies revealed that PE elevated gene expression of an array of hepatic antioxidant and carcinogen detoxifying enzymes in DENA-exposed animals. PE elevated protein and messenger RNA expression of the hepatic nuclear factor E2-related factor 2 (Nrf2). Our results provide substantial evidence, for the first time, that pomegranate constituents afford chemoprevention of hepatocarcinogenesis possibly through potent antioxidant activity achieved by upregulation of several housekeeping genes under the control of Nrf2 without toxicity. The outcome of this study strongly supports the development of pomegranate-derived products in the prevention and treatment of human HCC, which remains a devastating disease. PMID:21389260

Cancer Chemopreventive Ability of Conjugated Linolenic Acids

Directory of Open Access Journals (Sweden)

Kazuo Miyashita

2011-11-01

Full Text Available Conjugated fatty acids (CFA have received increased interest because of their beneficial effects on human health, including preventing cancer development. Conjugated linoleic acids (CLA are such CFA, and have been reviewed extensively for their multiple biological activities. In contrast to other types of CFAs including CLA that are found at low concentrations (less than 1% in natural products, conjugated linolenic acids (CLN are the only CFAs that occur in higher quantities in natural products. Some plant seeds contain a considerably high concentration of CLN (30 to 70 wt% lipid. Our research group has screened CLN from different plant seed oils to determine their cancer chemopreventive ability. This review describes the physiological functions of CLN isomers that occur in certain plant seeds. CLN are able to induce apoptosis through decrease of Bcl-2 protein in certain human cancer cell lines, increase expression of peroxisome proliferator-activated receptor (PPAR-γ, and up-regulate gene expression of p53. Findings in our preclinical animal studies have indicated that feeding with CLN resulted in inhibition of colorectal tumorigenesis through modulation of apoptosis and expression of PPARγ and p53. In this review, we summarize chemopreventive efficacy of CLN against cancer development, especially colorectal cancer.

Solvent effects on the magnetic shielding of tertiary butyl alcohol

African Journals Online (AJOL)

)4 and tetramethyl ammonium cation N(CH3)4(+) have also been presented. KEY WORDS: Solvent effects, Magnetic shielding, Tertiary butyl alcohol, Tertiary butyl amine, Continuum solvation calculations, Chemical shift estimation methods

Chronic unpredictable stress deteriorates the chemopreventive efficacy of pomegranate through oxidative stress pathway.

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Hasan, Shirin; Suhail, Nida; Bilal, Nayeem; Ashraf, Ghulam Md; Zaidi, Syed Kashif; AlNohair, Sultan; Banu, Naheed

2016-05-01

Chronic unpredictable stress (CUS) can influence the risk and progression of cancer through increased oxidative stress. Pomegranate is known to protect carcinogenesis through its anti-oxidative properties. This study is carried out to examine whether CUS affects the chemopreventive potential of pomegranate through oxidative stress pathway. Role of CUS on early stages of 7, 12 dimethyl benz(a) anthracene (DMBA) induced carcinogenesis, and its pre-exposure effect on chemopreventive efficacy of pomegranate juice (PJ) was examined in terms of in vivo antioxidant and biochemical parameters in Swiss albino rats. Rats were divided in various groups and were subjected to CUS paradigm, DMBA administration (65 mg/kg body weight, single dose), and PJ treatment. Exposure to stress (alone) and DMBA (alone) led to increased oxidative stress by significantly decreasing the antioxidant enzymes activities and altering the glutathione (GSH), malondialdehyde (MDA), glutamate oxaloacetate transaminase (GOT), and glutamate pyruvate transaminase (GPT) levels. A significant increase in DNA damage demonstrated by comet assay was seen in the liver cells. Stress exposure to DMBA-treated rats further increased the oxidative stress and disturbed the biochemical parameters as compared to DMBA (alone)-treated rats. Chemoprevention with PJ in DMBA (alone)-treated rats restored the altered parameters. However, in the pre-stress DMBA-treated rats, the overall antioxidant potential of PJ was significantly diminished. Our results indicate that chronic stress not only increases the severity of carcinogenesis but also diminishes the anti-oxidative efficacy of PJ. In a broader perspective, special emphasis should be given to stress management and healthy diet during cancer chemoprevention.

Chemoprevention of skin cancer by the flavonoid fraction of Saraca asoka.

Science.gov (United States)

Cibin, T R; Devi, D Gayathri; Abraham, Annie

2010-05-01

Saraca asoka (Family - Caesalpiniaceae) has been widely used in the Ayurvedic (traditional Indian) system of medicine especially due to its wound healing property. The present study investigated the chemopreventive property of flavonoids from the flowers of Saraca asoka on 7,12 dimethyl benz(a)anthracene (DMBA) induced skin cancer in mice models. A single topical application of DMBA (100 microg/50 microL of acetone) followed after 2 weeks by three times a week treatment with croton oil (1% in acetone), for 20 weeks resulted in tumor induction. The topical application of the flavonoid fraction of S. asoka (FF S. asoka), 30 min prior to the application of croton oil thrice weekly for 20 weeks, caused a significant reduction in the number of tumors per mouse and the percentage of tumor-bearing mice. Also the latency period for the appearance of the first tumor was delayed by S. asoka pretreatment. In the flavonoid fraction (5 mg and 10 mg/kg body weight) treated animals, the levels of biochemical markers - rhodanese, myeloperoxidase, beta-D-glucuronidase, sialic acid, hexokinase and caspase 3 were significantly restored to near normal levels. These findings suggest the chemopreventive activity of flavonoids from S. asoka on two stage skin carcinogenesis. Histological data also support the chemopreventive potential of S. asoka. Copyright (c) 2009 John Wiley & Sons, Ltd.

Synthesis of Poly (Butyl Methacrylate/Butyl Acrylate) Highly Absorptive Resin Using Glow Discharge Electrolysis

International Nuclear Information System (INIS)

Li Yan; Yao Mengqi; Liao Ruirui; Yang Wu; Gao Jinzhang; Ren Jie

2014-01-01

A highly absorptive resin poly (butyl methacrylate (BMA)-co-butyl acrylate (BA)) was prepared by emulsion polymerization, which was initiated by glow discharge electrolysis plasma (GDEP). The effects of discharge voltage, discharge time, monomer ratio and the amounts of cross-linking agent were examined and discussed in detail. The chemical structure of the obtained resin was characterized by means of attenuated total reflectance Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The optimal conditions were obtained as: discharge voltage was 600 V, discharge time was 8 min, the ratios of BMA:BA being 2:1 for chloroform and 3:1 for xylene, with 2% N, N'-methylenebis. Under optimal conditions, the oil absorbency was 70 g/g for chloroform and 46 g/g for xylene. Moreover, the absorptive dynamical behavior of the resulting resin was also investigated

Reversal of aflatoxin induced liver damage by turmeric and curcumin.

Science.gov (United States)

Soni, K B; Rajan, A; Kuttan, R

1992-09-30

The effect of certain food additives on aflatoxin production by Aspergillus parasiticus has been studied in vitro. Extracts of turmeric (Curcuma longa), garlic (Allium sativum) and asafoetida (Ferula asafoetida) inhibited the aflatoxin production considerably (more than 90%) at concentrations of 5-10 mg/ml. Similar results were also seen using butylated hydroxytoluene, butylated hydroxyanisole and ellagic acid at concentration 0.1 mM. Curcumin, the antioxidant principle from Curcuma longa did not have any effect on aflatoxin production. Turmeric and curcumin were also found to reverse the aflatoxin induced liver damage produced by feeding aflatoxin B1 (AFB1) (5 micrograms/day per 14 days) to ducklings. Fatty changes, necrosis and biliary hyperplasia produced by AFB1 were considerably reversed by these food additives.

Chemical composition, antioxidant properties and antimicrobial activity of the essential oil of Murraya paniculata leaves from the mountains of Central Cuba.

Science.gov (United States)

Rodríguez, Elisa Jorge; Ramis-Ramos, Guillermo; Heyden, Yvan Vander; Simó-Alfonso, Ernesto F; Lerma-García, María Jesús; Saucedo-Hernández, Yanelis; Monteagudo, Urbano; Morales, Yeni; Holgado, Beatriz; Herrero-Martínez, José Manuel

2012-11-01

The essential oil of Murraya paniculata L leaves from the mountains of the Central Region of Cuba, obtained by hydrodistillation, was analyzed by gas chromatography-mass spectrometry. Eighteen compounds, accounting for 95.1% of the oil were identified. The major component was beta-caryophyllene (ca. 30%). The antioxidant activity of essential oil was evaluated against Cucurbita seed oil by peroxide, thiobarbituric acid and p-anisidine methods. The essential oil showed stronger antioxidant activity than that of butylated hydroxyanisole and butylated hydroxytoluene, but lower than that of propyl gallate. Moreover, this antioxidant activity was supported by the complementary antioxidant assay in the linoleic acid system and 2, 2'-diphenyl-1-picrylhydrazyl. The essential oil also showed good to moderate inhibitory effects against Klebsiellapneumoniae and Bacillus subtilis.

Evidence supporting the conceptual framework of cancer chemoprevention in canines.

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Kondratyuk, Tamara P; Adrian, Julie Ann Luiz; Wright, Brian; Park, Eun-Jung; van Breemen, Richard B; Morris, Kenneth R; Pezzuto, John M

2016-05-24

As with human beings, dogs suffer from the consequences of cancer. We investigated the potential of a formulation comprised of resveratrol, ellagic acid, genistein, curcumin and quercetin to modulate biomarkers indicative of disease prevention. Dog biscuits were evaluated for palatability and ability to deliver the chemopreventive agents. The extent of endogenous DNA damage in peripheral blood lymphocytes from dogs given the dietary supplement or placebo showed no change. However, H2O2-inducible DNA damage was significantly decreased after consumption of the supplement. The expression of 11 of 84 genes related to oxidative stress was altered. Hematological parameters remained in the reference range. The concept of chemoprevention for the explicit benefit of the canine is compelling since dogs are an important part of our culture. Our results establish a proof-of-principle and provide a framework for improving the health and well-being of "man's best friend".

Catalytic oxidation of butyl acetate over silver-loaded zeolites

International Nuclear Information System (INIS)

Wong, Cheng Teng; Abdullah, Ahmad Zuhairi; Bhatia, Subhash

2008-01-01

The performance of silver-loaded zeolite (HY and HZSM-5) catalysts in the oxidation of butyl acetate as a model volatile organic compound (VOC) was studied. The objective was to find a catalyst with superior activity, selectivity towards deep oxidation product and stability. The catalyst activity was measured under excess oxygen condition in a packed bed reactor operated at gas hourly space velocity (GHSV) = 15,000-32,000 h -1 , reaction temperature between 150 and 500 deg. C and butyl acetate inlet concentration of 1000-4000 ppm. Both AgY and AgZSM-5 catalysts exhibited high activity in the oxidation of butyl acetate. Despite lower silver content, AgY showed better activity, attributed to better metal dispersion, surface characteristics and acidity, and its pore system. Total conversion of butyl acetate was achieved at above 400 deg. C. The oxidation of butyl acetate followed a simple power law model. The reaction orders, n and m were evaluated under differential mode by varying the VOC partial pressure between 0.004 and 0.018 atm and partial pressure of oxygen between 0.05 and 0.20 atm. The reaction rate was independent of oxygen concentration and single order with respect to VOC concentration. The activation energies were 19.78 kJ/mol for AgY and 32.26 kJ/mol for AgZSM-5, respectively

Study on the interaction of chemopreventive compounds and food born carcinogens with cytochrome P450 enzymes

OpenAIRE

Brabencová, Eliška

2013-01-01

The use of food supplements containing natural chemopreventive compounds increased in recent years. Some of the most popular chemopreventive compounds are flavonoids. Due to their natural origin, flavonoids are generally accepted as safe compounds. They exert antioxidant, anti-cancer and anti-inflammatory properties. However, flavonoids should be considered as foreign compounds (xenobiotics). Flavonoids interact with many enzymes, among the most important belong cytochromes P450 (CYPs), key e...

Breast cancer chemopreventive and chemotherapeutic effects of Camellia Sinensis (green tea): an updated review.

Science.gov (United States)

Rafieian-Kopaei, Mahmoud; Movahedi, Mino

2017-02-01

Camellia sinensis belongs to the plant family of Theaceae, native to East Asia, the Indian Subcontinent and Southeast Asia, but naturalized in many parts of the world. The aim of this study was to overview its anti-breast cancer chemopreventive and chemotherapeutic effects. This review article is aimed to overview breast cancer chemopreventive and chemotherapeutic effects of Camellia sinensis (green tea). This review article was carried out by searching studies in PubMed, Medline, Web of Science, and IranMedex databases. The initial search strategy identified around 108 references. In this study, 68 studies were accepted for further screening, and met all our inclusion criteria [in English, full text, chemopreventive and chemotherapeutic effects of Camellia sinensis and dated mainly from the year 1999 to 2016. The search terms were Camellia sinensis, chemopreventive, chemotherapeutic properties, pharmacological effects. The result of this study suggested that the catechin available in Camellia sinensis has properties which can prevent and treat breast cancer. It has also been shown to inhibit proliferation of breast cancer cells and to block carcinogenesis. It was found that increased Camellia sinensis consumption may lower the risk of breast cancer. Camellia sinensis intake was shown to reduce the risk of breast cancer incidence. In addition, potential breast cancer chemopreventive effect of Camellia sinensis both in vivo and in vitro was highly confirmed. However, the evidence of low effect and no effect was observed. More clinical trial studies are needed to prove its anti-breast cancer activity decisively. Camellia sinensis is broadly utilized as a part of customary medication since antiquated time because of its cost adequacy, and fewer reaction properties. The studies demonstrated anti-breast cancer activity of Camellia sinensis and its component by adjusting cell signaling pathways such as angiogenesis, apoptosis, and transcription factor. Furthermore

Colon Cancer Chemoprevention by Sage Tea Drinking: Decreased DNA Damage and Cell Proliferation.

Science.gov (United States)

Pedro, Dalila F N; Ramos, Alice A; Lima, Cristovao F; Baltazar, Fatima; Pereira-Wilson, Cristina

2016-02-01

Salvia officinalis and some of its isolated compounds have been found to be preventive of DNA damage and increased proliferation in vitro in colon cells. In the present study, we used the azoxymethane model to test effects of S. officinalis on colon cancer prevention in vivo. The results showed that sage treatment reduced the number of ACF formed only if administered before azoxymethane injection, demonstrating that sage tea drinking has a chemopreventive effect on colorectal cancer. A decrease in the proliferation marker Ki67 and in H2 O2 -induced and azoxymethane-induced DNA damage to colonocytes and lymphocytes were found with sage treatment. This confirms in vivo the chemopreventive effects of S. officinalis. Taken together, our results show that sage treatment prevented initiation phases of colon carcinogenesis, an effect due, at least in part, to DNA protection, and reduced proliferation rates of colon epithelial cell that prevent mutations and their fixation through cell replication. These chemopreventive effects of S. officinalis on colon cancer add to the many health benefits attributed to sage and encourage its consumption. Copyright © 2015 John Wiley & Sons, Ltd.

Comet Assay in Cancer Chemoprevention.

Science.gov (United States)

Santoro, Raffaela; Ferraiuolo, Maria; Morgano, Gian Paolo; Muti, Paola; Strano, Sabrina

2016-01-01

The comet assay can be useful in monitoring DNA damage in single cells caused by exposure to genotoxic agents, such as those causing air, water, and soil pollution (e.g., pesticides, dioxins, electromagnetic fields) and chemo- and radiotherapy in cancer patients, or in the assessment of genoprotective effects of chemopreventive molecules. Therefore, it has particular importance in the fields of pharmacology and toxicology, and in both environmental and human biomonitoring. It allows the detection of single strand breaks as well as double-strand breaks and can be used in both normal and cancer cells. Here we describe the alkali method for comet assay, which allows to detect both single- and double-strand DNA breaks.

The chemopreventive properties and therapeutic modulation of green tea polyphenols in oral squamous cell carcinoma.

Science.gov (United States)

Lee, Ui-Lyong; Choi, Sung-Weon

2011-01-01

Chemoprevention is a relatively novel and promising approach for controlling cancer that uses specific natural products or synthetic agents to suppress, reverse, or prevent premalignancy before transformation into invasive cancer. Oral cavity squamous cell carcinoma (OCSCC) represents a large, worldwide health burden with approximately 274,000 cases diagnosed annually worldwide. Smoking and alcohol consumption are major inducers of OCSCC. Recently, the human papilloma virus was also shown to potentially be an etiologic factor. Due to its easily identifiable risk factors and the presence of premalignant regions, oral cancer makes a good candidate for chemoprevention. Green tea is the most widely consumed beverage in the world, and it has received considerable attention because of its abundant, scientifically proven, beneficial effects on human health. In this review, we discuss the role of green tea in oral cancer chemoprevention with regard to the multiple molecular mechanisms proposed in various in vitro, in vivo, and clinical trials.

Determination of synthetic phenolic antioxidants in soft drinks by stir-bar sorptive extraction coupled to gas chromatography-mass spectrometry.

Science.gov (United States)

Cacho, Juan Ignacio; Campillo, Natalia; Viñas, Pilar; Hernández-Córdoba, Manuel

2015-01-01

The synthetic phenolic antioxidants butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) were pre-concentrated by stir-bar sorptive extraction and thermally desorbed (SBSE-TD) before analysis by GC-MS. Several parameters affecting the derivatisation step and both SBSE extraction and thermal desorption were carefully optimised. When the analyses of BHA and TBHQ in their acetylated, silylated and underivatised forms were compared, the best results were obtained when the in-situ derivatisation procedure with acetic anhydride was employed. Quantification was carried out using carvacrol as the internal standard, providing quantification limits of between 0.11 and 0.15 ng ml(-1), depending on the compound. Recovery assays for samples spiked at two concentration levels, 1 and 5 ng ml(-1), provided recoveries in the 81-117% range. The proposed method was applied in the analysis canned soft drinks and the analytes were found in five of the 10 samples analysed.

New Enlightenment of Skin Cancer Chemoprevention through Phytochemicals: In Vitro and In Vivo Studies and the Underlying Mechanisms.

Science.gov (United States)

Singh, Madhulika; Suman, Shankar; Shukla, Yogeshwer

2014-01-01

Skin cancer is still a major cause of morbidity and mortality worldwide. Skin overexposure to ultraviolet irradiations, chemicals, and several viruses has a capability to cause severe skin-related disorders including immunosuppression and skin cancer. These factors act in sequence at various steps of skin carcinogenesis via initiation, promotion, and/or progression. These days cancer chemoprevention is recognized as the most hopeful and novel approach to prevent, inhibit, or reverse the processes of carcinogenesis by intervention with natural products. Phytochemicals have antioxidant, antimutagenic, anticarcinogenic, and carcinogen detoxification capabilities thereby considered as efficient chemopreventive agents. Considerable efforts have been done to identify the phytochemicals which may possibly act on one or several molecular targets that modulate cellular processes such as inflammation, immunity, cell cycle progression, and apoptosis. Till date several phytochemicals in the light of chemoprevention have been studied by using suitable skin carcinogenic in vitro and in vivo models and proven as beneficial for prevention of skin cancer. This revision presents a comprehensive knowledge and the main molecular mechanisms of actions of various phytochemicals in the chemoprevention of skin cancer.

New Enlightenment of Skin Cancer Chemoprevention through Phytochemicals: In Vitro and In Vivo Studies and the Underlying Mechanisms

Directory of Open Access Journals (Sweden)

Madhulika Singh

2014-01-01

Full Text Available Skin cancer is still a major cause of morbidity and mortality worldwide. Skin overexposure to ultraviolet irradiations, chemicals, and several viruses has a capability to cause severe skin-related disorders including immunosuppression and skin cancer. These factors act in sequence at various steps of skin carcinogenesis via initiation, promotion, and/or progression. These days cancer chemoprevention is recognized as the most hopeful and novel approach to prevent, inhibit, or reverse the processes of carcinogenesis by intervention with natural products. Phytochemicals have antioxidant, antimutagenic, anticarcinogenic, and carcinogen detoxification capabilities thereby considered as efficient chemopreventive agents. Considerable efforts have been done to identify the phytochemicals which may possibly act on one or several molecular targets that modulate cellular processes such as inflammation, immunity, cell cycle progression, and apoptosis. Till date several phytochemicals in the light of chemoprevention have been studied by using suitable skin carcinogenic in vitro and in vivo models and proven as beneficial for prevention of skin cancer. This revision presents a comprehensive knowledge and the main molecular mechanisms of actions of various phytochemicals in the chemoprevention of skin cancer.

Chemopreventive Activity of Honokiol against 7, 12 - Dimethylbenz[a]anthracene-Induced Mammary Cancer in Female Sprague Dawley Rats

Directory of Open Access Journals (Sweden)

Zhenyu Wang

2017-05-01

Full Text Available Breast cancer is a predominant cause of death in women across the globe. Chemoprevention by using natural, dietary or synthetic products has been appearing to be a fascinating approach to combat the growing burden of breast cancer. In the current study, we intended to explore the mechanisms of chemopreventive action of honokiol against 7, 12 - dimethylbenz[a]anthracene (DMBA-induced mammary cancer in female Sprague Dawlely (SD rats. We induced mammary cancer in SD rats by administering single dose of DMBA (80 mg/kg through intra gastric route. Chemopreventive effects of honokiol (80 mg/kg, i.p. were confirmed from its ameliorating effect on the DMBA-induced anomalies such as liver marker enzymes, Phases I and II metabolizing enzymes and oxidative stress markers. Further, honokiol reversed the DMBA-induced abnormalities in inflammatory cytokines levels and serum tumor markers. Additionally, histopathological examination of mammary tissue and protein expression analysis of NF-κB revealed that honokiol is effective against DMBA-induced mammary cancer. In summary, the results of our study support the chemopreventive feature of honokiol in mammary cancer.

Chemopreventive Potential of Flavonoids in Oral Squamous Cell Carcinoma in Human Studies

Directory of Open Access Journals (Sweden)

Elena Maria Varoni

2013-07-01

Full Text Available Evidence available from nutritional epidemiology has indicated an inverse association between regular consumption of fruits and vegetables and the risk of developing certain types of cancer. In turn, preclinical studies have attributed the health-promoting effects of plant foods to some groups of phytochemicals, by virtue of their many biological activities. In this survey, we briefly examine the chemopreventive potential of flavonoids and flavonoid-rich foods in human oral carcinogenesis. Despite the paucity of data from clinical trials and epidemiological studies, in comparison to in vitro/in vivo investigations, a high level of evidence has been reported for epigallocatechin gallate (EGCG and anthocyanins. These flavonoids, abundant in green tea and black raspberries, respectively, represent promising chemopreventive agents in human oral cancer.

Effect of different antioxidants on lipid oxidation of irradiated cooked streaky pork

International Nuclear Information System (INIS)

Guo Shuzhen; Ha Yiming; Zhang Haiwei; Wang Feng; Liu Shuliang

2008-01-01

The effects of antioxidants on lipid oxidation of vacuum packaged irradiated cooked streaky pork were studied. The cooked streaky pork were added with 0.02% TeaPolyphenols (TP), rosemary, Tertiary butylhydroquinone (TBHQ), Butylated hydroxytoluene (BHT) and vitamin E separately, then were irradiated with 6 kGy, and stored at 4 degree C. The results showed that antioxidants can reduce the value of TBA, POV value of irradiated cooked streaky pork, and the effects of TBHQ and TP were better, than other antiatidins. (authors)

Update on the chemopreventive effects of ginger and its phytochemicals.

Science.gov (United States)

Baliga, Manjeshwar Shrinath; Haniadka, Raghavendra; Pereira, Manisha Maria; D'Souza, Jason Jerome; Pallaty, Princy Louis; Bhat, Harshith P; Popuri, Sandhya

2011-07-01

The rhizomes of Zingiber officinale Roscoe (Zingiberaceae), commonly known as ginger, is one of the most widely used spice and condiment. It is also an integral part of many traditional medicines and has been extensively used in Chinese, Ayurvedic, Tibb-Unani, Srilankan, Arabic, and African traditional medicines, since antiquity, for many unrelated human ailments including common colds, fever, sore throats, vomiting, motion sickness, gastrointestinal complications, indigestion, constipation, arthritis, rheumatism, sprains, muscular aches, pains, cramps, hypertension, dementia, fever, infectious diseases, and helminthiasis. The putative active compounds are nonvolatile pungent principles, namely gingerols, shogaols, paradols, and zingerone. These compounds are some of the extensively studied phytochemicals and account for the antioxidant, anti-inflammatory, antiemetic, and gastroprotective activities. A number of preclinical investigations with a wide variety of assay systems and carcinogens have shown that ginger and its compounds possess chemopreventive and antineoplastic effects. A number of mechanisms have been observed to be involved in the chemopreventive effects of ginger. The cancer preventive activities of ginger are supposed to be mainly due to free radical scavenging, antioxidant pathways, alteration of gene expressions, and induction of apoptosis, all of which contribute towards decrease in tumor initiation, promotion, and progression. This review provides concise information from preclinical studies with both cell culture models and relevant animal studies by focusing on the mechanisms responsible for the chemopreventive action. The conclusion describes directions for future research to establish its activity and utility as a human cancer preventive and therapeutic drug. The above-mentioned mechanisms of ginger seem to be promising for cancer prevention; however, further clinical studies are warranted to assess the efficacy and safety of ginger.

Grapefruit and its biomedical, antigenotoxic and chemopreventive properties.

Science.gov (United States)

Cristóbal-Luna, José Melesio; Álvarez-González, Isela; Madrigal-Bujaidar, Eduardo; Chamorro-Cevallos, Germán

2018-02-01

Grapefruit (Citrus paradisi Mcfad) is a perenifolium tree 5-6 m high with a fruit of about 15 cm in diameter, protected by the peel we can find about 11-14 segments (carpels), each of which is surrounded by a membrane and each containing the juice sacs, as well as the seeds. The fruit is made up of numerous compounds, and is known to have nutritive value because of the presence of various vitamins and minerals, among other chemicals. The fruit is also used in the field of gastronomy. Information has been accumulated regarding the participation of the fruit structures in a variety of biomedical, antigenotoxic and chemopreventive effects, surely related with the presence of the numerous chemicals that have been determined to constitute the fruit. Such studies have been carried out in different in vitro and in vivo experimental models, and in a few human assays. The information published so far has shown interesting results, therefore, the aims of the present review are to initially examine the main characteristics of the fruit, followed by systematization of the acquired knowledge concerning the biomedical, antigenotoxic and chemopreventive effects produced by the three main structures of the fruit: peel, seed, and pulp. Copyright © 2018 Elsevier Ltd. All rights reserved.

Synthesis of 4-tert-butyl-1,1-dimethylindan and 7-tert-Butyl-3,3-dimethyl-1-indanone and a comparison of isomers

International Nuclear Information System (INIS)

Eisenbraun, E.J.; Harms, W.M.; Paraniswamy, V.A.; Chen, H.H.; Porcaro, P.J.; Wood, T.F.; Chien, M.

1982-01-01

4-tert-Butyl-1,1-dimethylindan was synthesized to help establish the identity of products (5- and 6-tert-butyl-1,1-dimethylindan as minor and major products, respectively) from the sulfuric acid catalyzed condensation of tert-butylbenzene and isoprene. NMR ( 1 H and 13 C) studies of these hydrocarbons and their corresponding indanones, obtained through chromic acid oxidation, provided structural proof. Gated decoupling experiments were crucial to complete assignment

Colon Cancer Chemoprevention by Flavonoid Silibinin | Division of Cancer Prevention

Science.gov (United States)

DESCRIPTION (provided by applicant): Cancer stem cells (CSC) are now recognized as the main cause for initiation, promotion and progression of most of the cancers, including colorectal cancer (CRC). Despite this fact, efficacy of chemopreventive agents towards CSC generation leading to cancer initiation and tumorigenesis has not yet been well- defined. |

MRI to assess chemoprevention in transgenic adenocarcinoma of mouse prostate (TRAMP)

International Nuclear Information System (INIS)

Arbab, Ali S; Shankar, Adarsh; Varma, Nadimpalli RS; Deeb, Dorrah; Gao, Xiaohua; Iskander, ASM; Janic, Branislava; Ali, Meser M; Gautam, Subhash C

2011-01-01

The current method to determine the efficacy of chemoprevention in TRAMP mouse model of carcinoma of prostate (CaP) is by extracting and weighing the prostate at different time points or by immunohistochemistry analysis. Non-invasive determination of volumes of prostate glands and seminal vesicles before, during and after treatment would be valuable in investigating the efficacy of newer chemopreventive agents in CaP. The purpose of this study was to determine whether in vivo magnetic resonance imaging (MRI) using a 3 tesla clinical MRI system can be used to follow the effect of chemoprevention in TRAMP model of mouse CaP. Mice were randomized into control and treated groups. The animals in treated group received 10 µmol/kg of CDDO, 5 days a week for 20 weeks. Animals underwent in vivo MRI of prostate gland and seminal vesicles by a clinical 3 Tesla MRI system just before (at 5 weeks), during and at the end of treatment, at 25 weeks. T1-weighted and fat saturation (FATSAT) multiecho fast spin echo T2- weighted images (T2WI) were acquired. Volume of the prostate glands and seminal vesicles was determined from MR images. T2 signal intensity changes in the seminal vesicles were determined by subtracting higher echo time (TE) from lower TE T2WI. Following treatments all animals were sacrificed, prostate and seminal vesicles collected, and the tissues prepared for histological staining. All data were expressed as mean ± 1 standard deviation. Two-way or multivariate analysis of variance followed by post-hoc test was applied to determine the significant differences. A p-value of <0.05 was considered significant. Histological analysis indicated tumor in 100% of control mice, whereas 10% of the treated mice showed tumor in prostate gland. Both MRI and measured prostate weights showed higher volume/weight in control mouse group. MRI showed significantly higher volume of seminal vesicles in control animals and T2 signal intensity changes in seminal vesicles of control mice

Colon cancer chemoprevention with ginseng and other botanicals.

OpenAIRE

Wargovich, M J

2001-01-01

Colorectal cancer is becoming increasingly common in Asian countries and still remains the second leading cause of cancer deaths in the United States. Efforts to prevent colon cancer have targeted early detection through screening and chemoprevention. For the last ten years our laboratory has utilized an in vivo screening assay for the testing of potential cancer preventives for colon cancer. We have conducted investigations on over 150 compounds including many with botanical or herbal origin...

High energy radiation effects on mechanical properties of butyl rubber compounds

International Nuclear Information System (INIS)

Pozenato, Cristina A.; Scagliusi, Sandra R.; Cardoso, Elisabeth C.L.; Lugao, Ademar B.

2013-01-01

The high energy radiation on butyl rubber compounds causes a number of chemical reactions that occur after initial ionization and excitation events. These reactions lead to changes in molecular mass of the polymer through scission and crosslinking of the molecules, being able to affect the physical and mechanical properties. Butyl rubber has excellent mechanical properties and oxidation resistance as well as low gas and water vapor permeability. Due to all these properties butyl rubber is widely used industrially and particularly in tires manufacturing. In accordance with various authors, the major effect of high energy, such as gamma rays in butyl rubber, is the yielding of free-radicals along with changes in mechanical properties. There were evaluated effects imparted from high energy radiation on mechanical properties of butyl rubber compounds, non-irradiated and irradiated with 25 kGy, 50 kGy, 150 kGy and 200 kGy. It was also observed a sharp reducing in stress rupture and elongation at break for doses higher than 50 kGy, pointing toward changes in polymeric chain along build-up of free radicals and consequent degradation. (author)

Overview of mechanisms of cancer chemopreventive agents

International Nuclear Information System (INIS)

De Flora, Silvio; Ferguson, Lynnette R.

2005-01-01

Epidemiological data provide evidence that it is possible to prevent cancer and other chronic diseases, some of which share common pathogenetic mechanisms, such as DNA damage, oxidative stress, and chronic inflammation. An obvious approach is avoidance of exposure to recognized risk factors. As complementary strategies, it is possible to render the organism more resistant to mutagens/carcinogens and/or to inhibit progression of the disease by administering chemopreventive agents. In a primary prevention setting, addressed to apparently healthy individuals, it is possible to inhibit mutation and cancer initiation by triggering protective mechanisms either in the extracellular environment or inside cells, e.g., by modifying transmembrane transport, modulating metabolism, blocking reactive species, inhibiting cell replication, maintaining DNA structure, modulating DNA metabolism and repair, and controlling gene expression. Tumor promotion can be counteracted by inhibiting genotoxic effects, favoring antioxidant and anti-inflammatory activity, inhibiting proteases and cell proliferation, inducing cell differentiation, modulating apoptosis and signal transduction pathways, and protecting intercellular communications. In a secondary prevention setting, when a premalignant lesion has been detected, it is possible to inhibit tumor progression via the same mechanisms, and in addition by affecting the hormonal status and the immune system in various ways, and by inhibiting tumor angiogenesis. Although tertiary prevention, addressed to cancer patients after therapy, is outside the classical definition of chemoprevention, it exploits similar mechanisms. It is also possible to affect cell-adhesion molecules, to activate antimetastasis genes, and to inhibit proteases involved in basement membrane degradation

Aspirin Metabolomics in Colorectal Cancer Chemoprevention | Division of Cancer Prevention

Science.gov (United States)

Substantial evidence supports the effectiveness of aspirin for cancer chemoprevention in addition to its well-established role in cardiovascular protection. In recent meta-analyses of randomized controlled trials in humans, daily aspirin use reduced incidence, metastasis and mortality from several common types of cancer, especially colorectal cancer. The mechanism(s) by which

Recruitment strategies for a lung cancer chemoprevention trial involving ex-smokers.

Science.gov (United States)

Kye, Steve H; Tashkin, Donald P; Roth, Michael D; Adams, Bradley; Nie, Wen-Xian; Mao, Jenny T

2009-09-01

The ability to recruit qualified subjects who are willing to adhere to the study protocol in clinical trials is an essential component of translational research. Such tasks can be particularly challenging for chemoprevention studies when the targeted study population is healthy, at risk individuals who do not have signs or symptoms of the disease, and the study participation involves complex scheduling and invasive procedures such as bronchoscopy. In this report, we describe the recruitment process and evaluated the effectiveness of various recruitment strategies utilized in our National Cancer Institute sponsored lung cancer chemoprevention study with celecoxib. Heavy ex-smokers were recruited into the study through various methods such as radio advertisements, print media, mass mailings, flyers, internet postings and others. The number of inquiries, on-site screenees and randomization generated by each method determined the efficacy of that recruitment strategy. We prescreened 4470 individuals, invited 323 people for on-site screening and randomized 137 subjects. Radio advertisements (ads) generated the most inquiries (71.1%), followed by internet posting (11.8%), print media (6.0%), posted and racked flyers (4.4%), mass mailings (2.7%) and other strategies such as referrals from friends or family members or health care providers (2.3%). Radio ads, although costly, yielded the most subjects for on-site screening and randomization. Moreover, among the various types of radio stations, news radio stations were by far the most successful. Our results suggest that advertising on news radio is a highly effective recruitment method for successful accrual of ex-smokers into lung cancer chemoprevention trials.

Kaiware Daikon (Raphanus sativus L.) extract: a naturally multipotent chemopreventive agent.

Science.gov (United States)

Barillari, Jessica; Iori, Renato; Papi, Alessio; Orlandi, Marina; Bartolini, Giovanna; Gabbanini, Simone; Pedulli, Gian Franco; Valgimigli, Luca

2008-09-10

Brassica vegetables are attracting major attention as healthy foods because of their content of glucosinolates (GLs) that release the corresponding isothiocyanates (ITCs) upon myrosinase hydrolysis. A number of studies have so far documented the chemopreventive properties of some ITCs. On the other hand, single nutrients detached from the food itself risk being somewhat "reductive", since plants contain several classes of compounds endowed with a polyhedral mechanism of action. Our recent finding that 4-methylthio-3-butenyl isothiocyanate (GRH-ITC) and 4-methylsulfinyl-3-butenyl isothiocyanate (GRE-ITC), released by the GLs purified from Japanese (Kaiware) Daikon (Raphanus sativus L.) seeds and sprouts, had selective cytotoxic/apoptotic activity on three human colon carcinoma cell lines prompted further research on the potential chemopreventive role of a standardized Kaiware Daikon extract (KDE), containing 10.5% w/w GRH and 3.8% w/w GRE, compared to its isolated components. KDE administered in combination with myrosinase at doses corresponding to 50 microM GRH-ITC plus 15 microM GRE-ITC (50 microM KDE-ITC) to three human cancer cell lines (LoVo, HCT-116 and HT-29) significantly reduced cell growth by 94-96% of control in six days (p oxygen consumption rate), as monitored by Clark-type microelectrode oxygen-uptake kinetics, and induced very fast quenching of DPPH. radical in methanol with t(1/2) (s) = (1.47 +/- 0.25) x 10(-2)/[KDE; (g/L)], measured by stopped-flow UV-vis kinetics at 298 K. The potential chemopreventive role of KDE is discussed.

Antioxidant activity of wild edible plants in the Black Sea Region of Turkey

Energy Technology Data Exchange (ETDEWEB)

Ozen, T.

2010-07-01

The anti oxidative activity of the 80% ethanol extract obtained from eleven commonly consumed wild edible plants was determined according to the phospho molybdenum method, reducing power, metal chelating, superoxide anion and free radical scavenging activity and compared to standard compounds such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and trolox. Total phenolic compounds, flavonoids, and anthocyanins in the extracts were also measured. Trachystemon orientalis, Vaccinium mrytillus, Rumex acetosella Polygonum amphibium, Beta vulgaris, and Similax Excelsa had the highest antioxidant capacities. Overall results showed that these plants can serve as good sources of bioactive polyphenols in the human diet and can be regarded as good candidates for nutritional supplement formulations due to their high concentrations of total phenolic compounds, flavonoids and anthocyanins as well as their strong antioxidant activity. (Author) 42 refs.

Vertical flow soil filter for the elimination of micro pollutants from storm and waste water

DEFF Research Database (Denmark)

Janzen, Niklas; Banzhaf, Stefan; Scheytt, Traugott

2009-01-01

A technical scale activated soil filter has been used to study the elimination rates of diverse environmentally relevant micro pollutants from storm and waste water. The filter was made of layers of peat, sand and gravel. The upper (organic) layer was planted with reed (phragmites australis......) to prevent clogging and was spiked with activated sludge to enhance microbial biomass and biodegradation potential. Compounds used as UV filters, antioxidants or plasticizers, namely 4-methylbenzylidene camphor (4-MBC), benzophenone-3 (BP-3), butylated hydroxytoluene (BHT), N-butylbenzenesulfonamide (NBBS...

Null activity of selenium and vitamin e as cancer chemopreventive agents in the rat prostate.

Science.gov (United States)

McCormick, David L; Rao, K V N; Johnson, William D; Bosland, Maarten C; Lubet, Ronald A; Steele, Vernon E

2010-03-01

To evaluate the potential efficacy of selenium and vitamin E as inhibitors of prostate carcinogenesis, four chemoprevention studies using a common protocol were done in a rat model of androgen-dependent prostate cancer. After stimulation of prostate epithelial cell proliferation by a sequential regimen of cyproterone acetate followed by testosterone propionate, male Wistar-Unilever rats received a single i.v. injection of N-methyl-N-nitrosourea (MNU) followed by chronic androgen stimulation via subcutaneous implantation of testosterone pellets. At 1 week post-MNU, groups of carcinogen-treated rats (39-44/group) were fed either a basal diet or a basal diet supplemented with l-selenomethionine (3 or 1.5 mg/kg diet; study 1), dl-alpha-tocopherol (vitamin E, 4,000 or 2,000 mg/kg diet; study 2), l-selenomethionine + vitamin E (3 + 2,000 mg/kg diet or 3 + 500 mg/kg diet; study 3), or selenized yeast (target selenium levels of 9 or 3 mg/kg diet; study 4). Each chemoprevention study was terminated at 13 months post-MNU, and prostate cancer incidence was determined by histopathologic evaluation. No statistically significant reductions in prostate cancer incidence were identified in any group receiving dietary supplementation with selenium and/or vitamin E. These data do not support the hypotheses that selenium and vitamin E are potent cancer chemopreventive agents in the prostate, and when considered with the recent clinical data reported in the Selenium and Vitamin E Cancer Prevention Trial (SELECT), show the predictive nature of this animal model for human prostate cancer chemoprevention.

Chemoprevention utility of silibinin and Cdk4 pathway inhibition in Apc−/+ mice

International Nuclear Information System (INIS)

Karim, Baktiar O; Rhee, Ki-Jong; Liu, Guosheng; Zheng, Dongfeng; Huso, David L

2013-01-01

Colorectal cancer (CRC) is the second leading cause of death from cancer in the United States. Colorectal cancers have a prolonged latency following initiation that may span decades providing ample time for implementing a chemoprevention strategy that could block or reverse the progression to CRC. Cdk4 pathway alterations have been linked to a number of cancers including CRC. In these experiments we focused on the Cdk4 pathway and its role in intestinal tumorigenesis as a possible target in chemoprevention strategies. We evaluated the effect of Cdk4 blockade on the prevention of intestinal tumor formation by crossing Cdk4 −/− mice to Apc −/+ mice. In addition, we tested the effect of the dietary compound silibinin on the Cdk4 pathway in Apc −/+ mice and HT-29 colon cancer cells in culture. Cdk4 −/− mice backcrossed to Apc −/+ mice reduced intestinal adenoma formation compared to Apc −/+ controls. Silibinin effectively targeted the Cdk4 pathway causing hypophosphorylation of the retinoblastoma protein, inhibited cell growth, and induced apoptosis. As a result silibinin blocked the development of intestinal adenomas by 52% in this genetic model (Apc −/+ mice) of early events in colorectal cancer formation. No toxic abnormalities were detected in mice which received silibinin. Modification of the Cdk4 pathway using a natural plant-derived compound such as silibinin may be a useful chemopreventive strategy for colorectal carcinomas

Effect of a vegan diet on biomarkers of chemoprevention in females

NARCIS (Netherlands)

Verhagen, H.; Rauma, A.L.; Törrönen, R.; Vogel, N. de; Bruijntjes-Rozier, G.C.D.M.; Dreve, M.A.; Bogaards, J.J.P.; Mykkänen, H.

1996-01-01

1. In order to study the potential beneficial effects of a vegan diet, a cross-sectional study was performed and several biomarkers of chemoprevention were measured in a population of female 'living food' eaters ('vegans'; n = 20) vs matched omnivorous controls (n = 20). 2. White blood cells

A comparison of the effect of intranasal desmopressin and intramuscular hyoscine N-butyl bromide combination with intramuscular hyoscine N-butyl bromide alone in acute renal colic

Directory of Open Access Journals (Sweden)

Abdol-Reza Kheirollahi

2010-01-01

Full Text Available Background: Patients with acute renal colic usually require immediate diagnosis and treatment. In this clinical trial analgesic effect of hyoscine N-butyl bromide and desmopressin combination in comparison with hyoscine N-butyl bromide alone in patients with acute renal colic induced by urinary stones was assessed. Methods: The study included 114 patients randomly allocated in two groups (A and B. Patients in group A received 20 mg intramuscular hyoscine N-butyl bromide at admission time and patients in group B received 20 μg of intranasal desmopressin in combination with 20 mg intramuscular hyoscine N-butyl bromide. A visual analogue scale (VAS; a 10-cm horizontal scale ranging from "zero or no pain" to "10 or unbearable pain" was hired to assess the patients′ pain severity at baseline, 30 and 60 minutes after the treatments. Results: On admission, the pain level was similar in both groups (group A: 8.95 ± 0.11 and group B: 8.95 ± 0.12. In group A, the mean of pain level showed a decrease after 30 minutes (group A: 7.26 ± 0.25 and group B: 5.95 ± 0.28 but further decreasing did not occur; however in group B, the pain consistently decreased and the mean after 60 minutes was significantly decreased (group A: 6.80 ± 0.31 and group B: 3.71 ± 0.31. No side effects were detected in this study. Conclusions: The combination of hyoscine N-butyl bromide and desmopressin is more effective than hyoscine N-butyl bromide alone in patients with renal colic. Further studies are recommended to validate these findings and compare the different doses of desmopressin.

Curcumin and metformin-mediated chemoprevention of oral cancer is associated with inhibition of cancer stem cells.

Science.gov (United States)

Siddappa, Gangotri; Kulsum, Safeena; Ravindra, Doddathimmasandra Ramanjanappa; Kumar, Vinay V; Raju, Nalini; Raghavan, Nisheena; Sudheendra, Holalugunda Vittalamurthy; Sharma, Anupam; Sunny, Sumsum P; Jacob, Tina; Kuruvilla, Binu T; Benny, Merina; Antony, Benny; Seshadri, Mukund; Lakshminarayan, Padma; Hicks, Wesley; Suresh, Amritha; Kuriakose, Moni A

2017-11-01

Effective chemoprevention is critical for improving outcomes of oral cancer. As single agents, curcumin and metformin are reported to exhibit chemopreventive properties, in vitro as well as in patients with oral cancer. In this study, the chemopreventive efficacy of this drug combination was tested in a 4-nitro quinoline-1-oxide (4NQO) induced mice oral carcinogenesis model. Molecular analysis revealed a cancer stem cell (CSC)-driven oral carcinogenic progression in this model, wherein a progressive increase in the expression of CSC-specific markers (CD44 and CD133) was observed from 8th to 25th week, at transcript (40-100-fold) and protein levels (P ≤ 0.0001). Chemopreventive treatment of the animals at 17th week with curcumin and metformin indicated that the combination regimen decreased tumor volume when compared to the control arm (0.69+0.03 vs 6.66+2.4 mm 3 ; P = 0.04) and improved overall survival of the animals (P = 0.03). Assessment of the molecular status showed an overall downregulation of CSC markers in the treatment arms as compared to the untreated control. Further, in vitro assessment of the treatment on the primary cells generated from progressive stages of 4NQO-induced mice tissue showed a concordant and consistent downregulation of the CSC markers following combination treatment (P oral squamous cell carcinoma through a CSC-associated mechanism. © 2017 Wiley Periodicals, Inc.

Impact of di-n-butyl phthalate on reproductive system development in European pikeperch (Sander lucioperca

Directory of Open Access Journals (Sweden)

Sylwia Jarmołowicz

2013-01-01

Full Text Available Phthalic acid, di-n-butyl ester known as di-n-butyl phthalate, is an organic chemical compound that belongs to the group of endocrine disruptor compounds that have a documented negative impact on mammalian endocrine systems. Di-n-butyl phthalate is used widely as a plasticizer in the manufacture of artificial materials, which is why it is found in all types of environmental samples including those from water basins. The aim of the study was to describe the impact of di-n-butyl phthalate on the development of the reproductive system of European pikeperch (Sander lucioperca during the sex differentiation period (age 61–96 days post hatch. A total of 240 fish were divided into 6 groups (40 fish per tank. Treatments consisted of a control group (0 g di-n-butyl phthalate·kg-1 feed and five trial groups with 0.125, 0.25, 0.5, 1, and 2 g di-n-butyl phthalate·kg-1 feed, respectively. Histological changes of the fish gonads, sex ratio, survival and growth of fish were evaluated. Di-n-butyl phthalate seriously disturbed sex differentiation process of pikeperch. Histopathological analyses revealed that the administration of 2 g di-n-butyl phthalate·kg-1 significantly affected the sex ratio. The feminization process (intersex gonads at concentrations of 1 g and 2 g di-n-butyl phthalate·kg-1 were observed. All analyzed concentrations delayed testicular development. Phthalate did not have a significant impact on the survival or growth rates of the pikeperch. This is the first report of disruption sex differentiation processes in fish by di-n-butyl phthalate.

Pomegranate exerts chemoprevention of experimentally induced mammary tumorigenesis by suppression of cell proliferation and induction of apoptosis.

Science.gov (United States)

Bishayee, Anupam; Mandal, Animesh; Bhattacharyya, Piyali; Bhatia, Deepak

2016-01-01

Breast cancer is the second leading cause of cancer-related death in women in the United States and discovery and development of safe chemopreventive drugs is urgently needed. The fruit pomegranate (Punica granatum) is gaining importance because of its various health benefits. This study was initiated to investigate chemopreventive potential of a pomegranate emulsion (PE) against 7,12-dimethylbenz(a)anthracene (DMBA) rat mammary carcinogenesis. The animals were orally administered with PE (0.2-5.0 g/kg), starting 2 wk before and 16 wk following DMBA treatment. PE exhibited a striking reduction of DMBA-induced mammary tumor incidence, total tumor burden, and reversed histopathological changes. PE dose-dependently suppressed cell proliferation and induced apoptosis in mammary tumors. Immunohistochemical studies showed that PE increased intratumor Bax, decreased Bcl2 and manifested a proapoptotic shift in Bax/Bcl2 ratio. In addition, our gene expression study showed PE-mediated upregulation of Bad, caspase-3, caspase-7, caspase-9, poly (ADP ribose) polymerase and cytochrome c in mammary tumors. Thus, PE exerts chemoprevention of mammary carcinogenesis by suppressing cell proliferation and inducing apoptosis mediated through upregulation of Bax and downregulation of Bcl2 in concert with caspase cascades. Pomegranate bioactive phytoconstituents could be developed as a chemopreventive drug to reduce the risk of breast cancer.

Structures of butyl ions formed by electron impact ionization of isomeric butyl halides and alkanes

International Nuclear Information System (INIS)

Shold, D.M.; Ausloos, P.

1978-01-01

Using a pulsed ion cyclotron resonance (ICR) spectrometer, it is demonstrated that at pressures of about 10 -6 Torr and at observation times ranging from 10 -3 to 0.5 s, isobutane, neopentane, 2,2-dimethylbutane, isobutyl halides, and tert-butyl halides form C 4 H 9 + ions having the tertiary structure. In n-alkanes, 2-methylbutane, 3-methylpentane, n-butyl halides, and sec-butyl halides, both sec-C 4 H 9 + and t-C 4 H 9 + ions are observed, the sec-C 4 H 9 + ions surviving without rearrangement for at least 0.1 s. However, in the case of the halides, a collision-induced isomerization of the sec-C 4 H 9 + to the t-C 4 H 9 + ions occurs. The efficiency of this process increases with the basicity of the alkyl halide. Radiolysis experiments carried out at atmospheric pressures indicate, in agreement with ICR and solution experiments, that at times as short as 10 -10 s the majority of the i-C 4 H 9 + ions from isobutyl bromide rearrange to the t-C 4 H 9 + structure. On the other hand, in the radiolysis of both n-hexane and 3-methylpentane, the abundance of t-C 4 H 9 + relative to sec-C 4 H 9 + is substantially smaller than that observed in the ICR experiments, and decreases with decreasing collision interval. It is suggested that about 90% of the i-C 4 H 9 + can rearrange to t-C 4 H 9 + by simple 1,2-hydride shift without involving secondary or protonated methylcyclopropane structures as intermediates. 4 figures, 2 tables

Chemoprevention, chemotherapy, and chemoresistance in colorectal cancer.

Science.gov (United States)

Marin, Jose J G; Sanchez de Medina, Fermin; Castaño, Beatriz; Bujanda, Luis; Romero, Marta R; Martinez-Augustin, Olga; Moral-Avila, Rosario Del; Briz, Oscar

2012-05-01

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related death in industrialized countries. Chemoprevention is a promising approach, but studies demonstrating their usefulness in large populations are still needed. Among several compounds with chemopreventive ability, cyclooxygenase inhibitors have received particular attention. However, these agents are not without side effects, which must be weighed against their beneficial actions. Early diagnosis is critical in the management of CRC patients, because, in early stages, surgery is curative in >90% of cases. If diagnosis occurs at stages II and III, which is often the case, neoadjuvant chemotherapy and radiotherapy before surgery are, in a few cases, recommended. Because of the high risk of recurrence in advanced cancers, chemotherapy is maintained after tumor resection. Chemotherapy is also indicated when the patient has metastases and in advanced cancer located in the rectum. In the last decade, the use of anticancer drugs in monotherapy or in combined regimens has markedly increased the survival of patients with CRC at stages III and IV. Although the rate of success is higher than in other gastrointestinal tumors, adverse effects and development of chemoresistance are important limitations to pharmacological therapy. Genetic profiling regarding mechanisms of chemoresistance are needed to carry out individualized prediction of the lack of effectiveness of pharmacological regimens. This would minimize side effects and prevent the selection of aggressive, cross-resistant clones, as well as avoiding undesirable delays in the use of the most efficient therapeutic approaches to treat these patients.

Phase 0 Clinical Chemoprevention Trial of the AKT Inhibitor SR13668

Science.gov (United States)

Reid, Joel M.; Walden, Chad; Qin, Rui; Allen Ziegler, Katie L.; Haslam, John L.; Rajewski, Roger A.; Warndahl, Roger; Fitting, Cindy L.; Boring, Daniel; Szabo, Eva; Crowell, James; Perloff, Marjorie; Jong, Ling; Mandrekar, Sumithra J.; Ames, Matthew M.; Limburg, Paul J.

2011-01-01

Purpose SR13668, an orally active AKT pathway inhibitor, has demonstrated cancer chemopreventive potential in preclinical studies. To accelerate the clinical development of this promising agent, we designed and conducted the first-ever phase 0 chemoprevention trial to evaluate and compare the effects of food and formulation on SR13668 bioavailability. Patients and Methods Healthy adult volunteers were randomly assigned to receive a single, 38 mg oral dose of SR13668 in one of five different formulations, with or without food. Based on existing animal data, SR13668 in a PEG400/Labrasol® oral solution was defined as the reference formulation. Blood samples were obtained pre- and post-agent administration for pharmacokinetic analyses. Area under the plasma concentration-time curve (AUC0-∞) was defined as the primary endpoint. Data were analyzed and compared using established statistical methods for phase 0 trials with a limited sample size. Results Participants (N=20) were rapidly accrued over a 5-month period. Complete pharmacokinetic data were available for 18 randomized participants. AUC0-∞ values were highest in the fed state (range = 122–439 ng/mL × hours) and were statistically significantly different across formulations (p = 0.007), with Solutol® HS15 providing the highest bioavailability. SR13668 time to peak plasma concentration (3 hours; range, 2 – 6 hours) and half-life were (11.2 ± 3.1 hours) were not formulation dependent. Conclusions Using a novel, highly efficient study design, we rapidly identified a lead formulation of SR13668 for further clinical testing. Our findings support application of the phase 0 trial paradigm to accelerate chemoprevention agent development. PMID:21372034

76 FR 77709 - Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption

Science.gov (United States)

2011-12-14

...This regulation establishes an exemption from the requirement of a tolerance for residues of 2-Propenoic acid, 2-methyl-, polymer with butyl 2-propenoate and ethenylbenzene (CAS Reg. No. 25036-16-2); also known as butyl acrylate-methacrylic acid-styrene polymer when used as an inert ingredient in a pesticide chemical formulation. Momentive Performance Materials submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), requesting an exemption from the requirement of a tolerance. This regulation eliminates the need to establish a maximum permissible level for residues of 2-Propenoic acid, 2-methyl-, polymer with butyl 2-propenoate and ethenylbenzene on food or feed commodities.

APPLICATION OF PHOTOCATALYTIC PROCESS FOR REMOVAL OF METHYL TERT-BUTYL ETHER FROM HIGHLYCONTAMINATED WATER

Directory of Open Access Journals (Sweden)

A. Mesdaghinia

2007-09-01

Full Text Available The oxygenate methyl tert-butyl ether is added to gasoline to increase the octane level and to reduce carbon monoxide and hydrocarbon emissions by vehicles. The high mobility, water solubility, and resistance to natural attenuation associated with methyl tert-butyl ether may result in contamination of ground and surface waters. In this research the degradation of aqueous methyl tert-butyl ether at relatively high concentrations was investigated by UV-vis/TiO2/H2O2 photocatalytic process. The effect of important operational parameters such as pH, amount of H2O2, catalyst loading, and irradiation time were also studied. Concentrations of methyl tert-butyl ether and intermediates such as tert-butyl formate and tert-butyl alcohol were measured over a 180 min period using a gas chromatograph equipped with flame ionization detector and combined with headspace sampler. Results showed that the time required for complete degradation increased from 30 to 180min, when the initial concentration was increased from 10 to 500mg/L. The first order rate constant for degradation of methyl tert-butyl ether from the hydroxyl radical was estimated to be 0.177 to 0.022 1/min as the concentration increased from 10 to 500mg/L. Study on the overall mineralization monitored by total organic carbon (TOC analysis showed that in the initial concentration of 100mg/L methyl tert-butyl ether, complete mineralization was obtained after 110min under UV-vis/TiO2/H2O2 photocatalytic process.

Cyclooxygenase as a target for chemoprevention in colorectal cancer: lost cause or a concept coming of age?

LENUS (Irish Health Repository)

Doherty, Glen A

2009-02-01

COX-2 is upregulated at an early stage in colorectal carcinogenesis and generates prostaglandins, which promote cancer cell proliferation, impair apoptosis and enhance angiogenesis, promoting tumour growth and metastasis. There are ample data from animal models and human studies to demonstrate enhanced tumour progression associated with COX-2 activity in cancer cells. Conversely, NSAIDs including aspirin inhibit COX-2 and, therefore, have anti-neoplastic properties. There has been sustained interest in COX-2 as a chemopreventive target in colorectal cancer (CRC) and although both aspirin and COX-2 selective NSAIDs have demonstrated efficacy, adverse effects have limited their widespread adoption. In particular, evidence of the cardiovascular effects of COX-2 selective inhibitors has led to questioning of the suitability of COX-2 as a target for chemoprevention. This review examines the basis for targeting COX-2 in CRC chemoprevention, evaluates the efficacy and safety of the approach and examines future strategies in this area.

Isothermal (vapor + liquid) equilibria and excess enthalpy data of {1-hexene + methyl butyl ether (MBE)} and {1-hexene + methyl tert-butyl ether (MTBE)} binary systems at several temperatures

International Nuclear Information System (INIS)

Hani, Rachida; Solimando, Roland; Negadi, Latifa; Jose, Jacques; Ait Kaci, Ahmed

2012-01-01

Highlights: ► Vapor pressures of (1-hexene + methyl butyl ether) or (1-hexene + methyl tert-butyl ether) are reported between (263 and 363) K. ► The two mixtures exhibit positive G E . ► Additionally, molar excess enthalpies, H E , for the two binary systems have been measured at 303.15. - Abstract: The vapor pressures of {1-hexene + methyl butyl ether (MBE)} and {1-hexene + methyl tert-butyl ether (MTBE)} binary mixtures and of the three pure components were measured by means of a static device at temperatures between (263 and 333) K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions were calculated for several constant temperatures and fitted to a third-order Redlich–Kister equation using the Barker’s method. Additionally, molar excess enthalpies, H E , for the two binary systems have been measured at 303.15 K using an isothermal flow calorimeter.

Trianthema portulacastrum Linn. exerts chemoprevention of 7,12-dimethylbenz(a)anthracene-induced mammary tumorigenesis in rats

Energy Technology Data Exchange (ETDEWEB)

Bishayee, Anupam, E-mail: abishayee@auhs.edu [Department of Pharmaceutical Sciences, School of Pharmacy, American University of Health Sciences, Signal Hill, CA 90755 (United States); Mandal, Animesh [Cancer Therapeutics and Chemoprevention Group, Department of Pharmaceutical Sciences, College of Pharmacy, Northeast Ohio Medical University, Rootstown, OH 44272 (United States)

2014-10-15

Highlights: • Dietary administration of an ethanolic extract of aerial parts of T. portulacastrum (TPE) exhibits a striking chemopreventive effect in an experimentally induced classical animal model of breast cancer. • The mammary tumor-inhibitory effect of TPE could be achieved, at least in part, though intervention of key hallmark capabilities of tumor cells, such as abnormal cell proliferation and evasion of apoptosis. • TPE is capable of diminishing activated canonical Wnt/β-catenin signaling to exhibit antiproliferative, proapoptotic and oncostatic effects during this early-stage mammary carcinoma. • These results coupled with a safety profile of T. portulacastrum may encourage further studies to understand the full potential of this dietary plant for chemoprevention of breast cancer. - Abstract: Due to limited treatment options for advanced-stage metastatic breast cancer, a high priority should be given to develop non-toxic chemopreventive drugs. The value of various natural and dietary agents to reduce the risk of developing breast cancer is well established. Trianthema portulacastrum Linn. (Aizoaceae), a dietary and medicinal plant, has been found to exert antihepatotoxic and antihepatocarcinogenic properties in rodents. This study was initiated to investigate mechanism-based chemopreventive potential of an ethanolic extract of T. portulacastrum (TPE) against 7,12-dimethylbenz(a)anthracene (DMBA)-initiated rat mammary gland carcinogenesis, an experimental tumor model that closely resembles human breast cancer. Rats had access to a basal diet supplemented with TPE to yield three dietary doses of the extract, i.e., 50, 100 and 200 mg/kg body weight. Following two weeks of TPE treatment, mammary tumorigenesis was initiated by oral administration of DMBA (50 mg/kg body weight). At the end of the study (16 weeks after DMBA exposure), TPE exhibited a striking reduction of DMBA-induced mammary tumor incidence, total tumor burden and average tumor weight

Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

Energy Technology Data Exchange (ETDEWEB)

Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)

2015-04-10

Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

Graphite nanocomposites sensor for multiplex detection of antioxidants in food.

Science.gov (United States)

Ng, Khan Loon; Tan, Guan Huat; Khor, Sook Mei

2017-12-15

Butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and tert-butylhydroquinone (TBHQ) are synthetic antioxidants used in the food industry. Herein, we describe the development of a novel graphite nanocomposite-based electrochemical sensor for the multiplex detection and measurement of BHA, BHT, and TBHQ levels in complex food samples using a linear sweep voltammetry technique. Moreover, our newly established analytical method exhibited good sensitivity, limit of detection, limit of quantitation, and selectivity. The accuracy and reliability of analytical results were challenged by method validation and comparison with the results of the liquid chromatography method, where a linear correlation of more than 0.99 was achieved. The addition of sodium dodecyl sulfate as supporting additive further enhanced the LSV response (anodic peak current, I pa ) of BHA and BHT by 2- and 20-times, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Amended final report on the safety assessment of PPG-40 butyl ether with an addendum to include PPG-2, -4, -5, -9, -12, -14, -15, -16, -17, -18, -20, -22, -24, -26, -30, -33, -52, and -53 butyl ethers.

Science.gov (United States)

Lanigan, R S

2001-01-01

The Polypropylene Glycol (PPG) Butyl Ethers function as skinand hair-conditioning agents in cosmetics. Intestinal absorption of the PPG Butyl Ethers was inversely proportional to the molecular weight. In general, the toxicity of the PPG Butyl Ethers decreased as the molecular weight increased. In acute studies, moderate intraperitoneal (IP) doses of various PPG Butyl Ethers caused convulsive seizures in mice and anesthetized dogs, and large oral doses caused decreased activity, anuria, renal tubular swelling and necrosis, and hepatic swelling and necrosis. PPG-2 Butyl Ether vapors were nontoxic by the inhalation route. PPG-2 Butyl Ether was nontoxic in short-term feeding and dermal exposure studies in rats. In animal irritation studies, PPG-2 Butyl Ether caused minor, transient erythema and desquamation; in addition, erythema, edema, ecchymosis, necrosis, and other changes were observed during an acute percutaneous study. PPG-2 Butyl Ether also caused minor to moderate conjunctival irritation and minor corneal injury. PPG-2 Butyl Ether when dermally applied was nontoxic to pregnant rats and was nonteratogenic at doses up to 1.0 ml/kg/day. PPG BE800 at concentrations of 0.001% to 0.26% in feed was noncarcinogenic to rats after 2 years of treatment. In clinical studies, PPG BE800 was nonirritating and nonsensitizing to the skin when tested using 200 subjects. PPG-40 Butyl Ether was neither an irritant nor a sensitizer in a repeat-insult patch test using 112 subjects. Although clinical testing did not indicate significant skin irritation is produced by these ingredients, the animal test data did indicate the potential that these ingredients can be irritating. Therefore, it was concluded that the PPG Butyl Ethers can be used safely in cosmetic products if they are formulated to avoid irritation. Data on the component ingredients, Propylene Glycol, PPG, and n-Butyl Alcohol, from previous cosmetic ingredient safety assessments were also considered and found to support

Curcumin and Other Polyphenolic Compounds in Head and Neck Cancer Chemoprevention

Directory of Open Access Journals (Sweden)

Philipp Baumeister

2012-01-01

Full Text Available Despite clear results of observational studies linking a diet rich in fruits and vegetables to a decreased cancer risk, large interventional trials evaluating the impact of dietary micronutrient supplementation, mostly vitamins, could not show any beneficial effects. Today it has become clear that a single micronutrient, given in supernutritional doses, cannot match cancer preventive effects of whole fruits and vegetables. In this regard polyphenols came into focus, not only because of their antioxidant potential but also because of their ability to interact with molecular targets within the cells. Because polyphenols occur in many foods and beverages in high concentration and evidence for their anticancer activity is best for tissues they can come into direct contact with, field cancerization predestines upper aerodigestive tract epithelium for cancer chemoprevention by polyphenols. In this paper, we summarize cancer chemopreventive attempts with emphasis on head and neck carcinogenesis and discuss some methodological issues. We present data regarding antimutagenic effects of curcumin and epigallocatechin-3-gallate in human oropharyngeal mucosa cultures exposed to cigarette smoke condensate.

Temporary diplopia upon hyoscine-N-butyl bromide administration: case report

Directory of Open Access Journals (Sweden)

Migliorini R

2013-05-01

Full Text Available R Migliorini, R Malagola, M Mafrici, R Spena, L ArricoDepartment of Sense Organs, University of Rome "La Sapienza", Rome, ItalyAbstract: Hyoscine-N-butyl bromide is a widely used antispasmodic belonging to the belladonna alkaloid class of semisynthetic quaternary ammonium compounds. These compounds exert a spasmolytic action on the smooth muscles of the bile-gastrointestinal tract, genitourinary tract, salivary glands (xerostomia, and also on the visual apparatus – in particular, the irido-ciliary complex. As a consequence, they provoke collateral effects such as mydriasis and accommodation disturbances. We report the case of a 23-year-old woman who complained of not only "dry mouth" but also "cloudy vision" and a "diplopia", both of temporary type, 2 hours after oral administration of hyoscine-N-butyl bromide.Keywords: hyoscine-N-butyl bromide, accommodation disorders, temporary diplopia, fusion alteration, vertical strabismus

PPARγ Ligand as a Promising Candidate for Colorectal Cancer Chemoprevention: A Pilot Study

Directory of Open Access Journals (Sweden)

Hirokazu Takahashi

2010-01-01

Full Text Available Activating synthetic ligands for peroxisome proliferator-activated receptor gamma (PPARγ, such as pioglitazone, are commonly used to treat persons with diabetes mellitus with improvement of insulin resistance. Several reports have clearly demonstrated that PPARγ ligands could inhibit colorectal cancer cell growth and induce apoptosis. Meanwhile, aberrant crypt foci (ACF have come to be established as a biomarker of the risk of CRC in azoxymethane-treated mice and rats. In humans, ACF can be detected using magnifying colonoscopy. Previously, CRC and adenoma were used as a target for chemopreventive agents, but it needs a long time to evaluate, however, ACF can be a surrogate marker of CRC even for a brief period. In this clinical study, we investigated the chemopreventive effect of pioglitazone on the development of human ACF as a surrogate marker of CRC. Twenty-nine patients were divided into two groups, 20 were in the endoscopically normal control group and 9 were in the pioglitazone (15 mg/day group, and ACF and adenoma were examined before and after 1-month treatment. The number of ACF was significantly decreased (5.8±1.1 to 3.3±2.3 after 1 month of pioglitazone treatment, however, there was no significant change in the number of crypts/ACF or in the number and size of adenomas. Pioglitazone may have a clinical application as a cancer-preventive drug. This investigation is just a pilot study, therefore, further clinical studies are needed to show that the PPARγ ligand may be a promising candidate as a chemopreventive agent for colorectal carcinogenesis.

Preparation and characterization of emulsifier-free polyphenylsilsesquioxane-poly (styrene–butyl acrylate) hybrid particles

Energy Technology Data Exchange (ETDEWEB)

Bai, Ruiqin; Qiu, Teng, E-mail: qiuteng@mail.buct.edu.cn; Han, Feng; He, Lifan; Li, Xiaoyu, E-mail: lixy@mail.buct.edu.cn

2013-10-01

The core–shell polyphenylsilsesquioxane-poly (styrene–butyl acrylate) hybrid latex paticles with polyphenylsilsesquioxane as core and poly (styrene–butyl acrylate) as shell were successfully synthesized by seeded emulsion polymerization using polyphenylsisesquioxane (PPSQ) latex particles as seeds. X-ray diffraction (XRD) indicated that the polyphenylsilsesquioxane (PPSQ) had ladder structure, and PPSQ had incorporated into the hybrid latex particles. Transmission electron microscopy (TEM) confirmed that the resultant hybrid latex particles had the core–shell structure. TEM and dynamic light scattering (DLS) analysis indicated that the polyphenylsisesquioxane latex particles and obtained core–shell hybrid latex particles were uniform and possessed narrow size distributions. X-ray photoelectron spectroscopy (XPS) analysis also indicated that the PPSQ core particles were enwrapped by the polymer shell. In addition, compared with pure poly (styrene–butyl acrylate) latex film, the polyphenylsilsesquioxane-poly (styrene–butyl acrylate) hybrid latex film exhibited lower water uptake, higher pencil hardness and better thermal stability.

Drug delivery strategies for chemoprevention of UVB-induced skin cancer: A review.

Science.gov (United States)

Bagde, Arvind; Mondal, Arindam; Singh, Mandip

2018-01-01

Annually, more skin cancer cases are diagnosed than the collective incidence of the colon, lung, breast, and prostate cancer. Persistent contact with sunlight is a primary cause for all the skin malignancies. UVB radiation induces reactive oxygen species (ROS) production in the skin which eventually leads to DNA damage and mutation. Various delivery approaches for the skin cancer treatment/prevention have been evolving and are directed toward improvements in terms of delivery modes, therapeutic agents, and site-specificity of therapeutics delivery. The effective chemoprevention activity achieved is based on the efficiency of the delivery system used and the amount of the therapeutic molecule deposited in the skin. In this article, we have discussed different studies performed specifically for the chemoprevention of UVB-induced skin cancer. Ultra-flexible nanocarriers, transethosomes nanocarriers, silica nanoparticles, silver nanoparticles, nanocapsule suspensions, microemulsion, nanoemulsion, and polymeric nanoparticles which have been used so far to deliver the desired drug molecule for preventing the UVB-induced skin cancer. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Regulatory approval of cancer risk-reducing (chemopreventive) drugs: moving what we have learned into the clinic.

Science.gov (United States)

Meyskens, Frank L; Curt, Gregory A; Brenner, Dean E; Gordon, Gary; Herberman, Ronald B; Finn, Olivera; Kelloff, Gary J; Khleif, Samir N; Sigman, Caroline C; Szabo, Eva

2011-03-01

This article endeavors to clarify the current requirements and status of regulatory approval for chemoprevention (risk reduction) drugs and discusses possible improvements to the regulatory pathway for chemoprevention. Covering a wide range of topics in as much depth as space allows, this report is written in a style to facilitate the understanding of nonscientists and to serve as a framework for informing the directions of experts engaged more deeply with this issue. Key topics we cover here are as follows: a history of definitive cancer chemoprevention trials and their influence on the evolution of regulatory assessments; a brief review of the long-standing success of pharmacologic risk reduction of cardiovascular diseases and its relevance to approval for cancer risk reduction drugs; the use and limitations of biomarkers for developing and the approval of cancer risk reduction drugs; the identification of individuals at a high(er) risk for cancer and who are appropriate candidates for risk reduction drugs; business models that should incentivize pharmaceutical industry investment in cancer risk reduction; a summary of scientific and institutional barriers to development of cancer risk reduction drugs; and a summary of major recommendations that should help facilitate the pathway to regulatory approval for pharmacologic cancer risk reduction drugs.

Final report of the addendum to the safety assessment of n-butyl alcohol as used in cosmetics.

Science.gov (United States)

McLain, Valerie C

2008-01-01

n-Butyl Alcohol is a primary aliphatic alcohol historically used as a solvent in nail care cosmetic products, but new concentration of use data indicate that it also is being used at low concentrations in eye makeup, personal hygiene, and shaving cosmetic products. n-Butyl Alcohol has been generally recognized as safe for use as a flavoring substance in food and appears on the 1982 Food and Drug Administration (FDA) list of inactive ingredients for approved prescription drug products. n-Butyl Alcohol can be absorbed through the skin, lungs, and gastrointestinal tract. n-Butyl Alcohol may be formed by hydrolysis of butyl acetate in the blood, but is rapidly oxidized. The single oral dose LD(50) of n-Butyl Alcohol for rats was 0.79 to 4.36 g/kg. The dermal LD(50) for rabbits was 4.2 g/kg. Inhalation toxicity studies in humans demonstrate sensory irritation of the upper respiratory tract, but only at levels above 3000 mg/m(3). Animal studies demonstrate intoxication, restlessness, ataxia, prostration, and narcosis. Exposures of rats to levels up to 4000 ppm failed to produce hearing defects. High concentrations of n-Butyl Alcohol vapors can be fatal. Ocular irritation was observed for n-Butyl alcohol at 0.005 ml of a 40% solution. The behavioral no-effect dose for n-Butyl Alcohol injected subcutaneously (s.c.) was 120 mg/kg. Fetotoxicity has been demonstrated, but only at maternally toxic levels (1000 mg/kg). No significant behavioral or neurochemical effects were seen in offspring following either maternal or paternal exposure to 3000 or 6000 ppm. n-Butyl Alcohol was not mutagenic in Ames tests, did not induce sister-chromatid exchange or chromosome breakage in chick embryos or Chinese hamster ovary cells, did not induce micronuclei formation in V79 Chinese hamster cells, did not have any chromosome-damaging effects in a mouse micronucleus test, and did not impair chromosome distribution in the course of mitosis. Clinical testing of n-Butyl Alcohol for

Methyl biodiesel from Dipteryx lacunifera: preparation, characterization and effect of antioxidant on the oxidation stability

International Nuclear Information System (INIS)

Araujo, Francisca Diana da Silva; Moura, Carla Veronica Rodarte de; Chaves, Mariana H.

2010-01-01

The objective of this work was to study the potentialities of Dipteryx lacunifera Ducke seeds oil for biodiesel production. The yield in oil was of 46.11 ± 0.37%. Methyl biodiesel was prepared by base catalyzed transesterification yielding 88.13% and percentage conversion of triglycerides to corresponding methyl ester of 89.1%. The addition of the tertiary butylhydroquinone (TBHQ, 50 ppm), butylated hydroxytoluene (BHT, 50 ppm) and cashew nut shell liquid (CNSL, 2000 ppm) antioxidants in the biodiesel contributed to the increase of the induction period of 2.97 h for 8.08; 6.06 and 6.02 h, respectively. (author)

Thermodynamic properties of 4-tert-butyl-diphenyl oxide

International Nuclear Information System (INIS)

Druzhinina, A.I.; Pimenova, S.M.; Tarazanov, S.V.; Nesterova, T.N.; Varushchenko, R.M.

2015-01-01

Highlights: • The sample of the 4-tert-butyl-diphenyl oxide was synthesized and purified. • Heat capacities, energy of combustion, saturation vapor pressures were measured. • The temperature, the enthalpy and the entropy of fusion were determined. • The enthalpy of sublimation at T = 298.15 K was derived. • The main thermodynamic functions and functions of formation were computed. - Abstract: The main thermodynamic functions (changes of the entropy, enthalpy, and Gibbs free energy) and functions of formation at T = 298.15 K of 4-tert-butyl-diphenyl oxide in condensed and ideal gas states were computed on the basis of experimental results obtained. The heat capacities of 4-tert-butyl-diphenyl oxide was measured by vacuum adiabatic calorimetry over the temperature range (8 to 371) K. The temperature, the enthalpy and the entropy of fusion were determined. The energy of combustion of the sample was determined by static-bomb combustion calorimetry. The saturation vapor pressures of the substance were measured by dynamic transpiration method over the temperature and pressure intervals (298 to 325) K and (0.05 to 1.2) Pa. The enthalpy of sublimation at T = 298.15 K was derived. The contribution of O-(2C b ) group (where C b is the carbon atom in a benzene ring) into the absolute entropies of diphenyl oxide derivatives was assessed

Carcinogenicity of chromium and chemoprevention: a brief update

Directory of Open Access Journals (Sweden)

Wang Y

2017-08-01

Full Text Available Yafei Wang,1,* Hong Su,1,* Yuanliang Gu,1 Xin Song,1 Jinshun Zhao1,2 1Department of Preventative Medicine, Zhejiang Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, People’s Republic of China; 2Toxicology and Molecular Biology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, USA *These authors contributed equally to this work Abstract: Chromium has two main valence states: hexavalent chromium (Cr[VI] and trivalent chromium (Cr[III]. Cr(VI, a well-established human carcinogen, can enter cells by way of a sulfate/phosphate anion-transport system, and then be reduced to lower-valence intermediates consisting of pentavalent chromium (Cr[V], tetravalent chromium (Cr[IV] or Cr(III via cellular reductants. These intermediates may directly or indirectly result in DNA damage or DNA–protein cross-links. Although Cr(III complexes cannot pass easily through cell membranes, they have the ability to accumulate around cells to induce cell-surface morphological alteration and result in cell-membrane lipid injuries via disruption of cellular functions and integrity, and finally to cause DNA damage. In recent years, more research, including in vitro, in vivo, and epidemiological studies, has been conducted to evaluate the genotoxicity/carcinogenicity induced by Cr(VI and/or Cr(III compounds. At the same time, various therapeutic agents, especially antioxidants, have been explored through in vitro and in vivo studies for preventing chromium-induced genotoxicity/carcinogenesis. This review aims to provide a brief update on the carcinogenicity of Cr(VI and Cr(III and chemoprevention with different antioxidants. Keywords: hexavalent chromium, Cr(VI, trivalent chromium, Cr(III, genotoxicity, carcinogenicity, chemoprevention, antioxidant 

Solvent free lipase catalyzed synthesis of butyl caprylate

Indian Academy of Sciences (India)

MEERA T SOSE

2017-11-10

Nov 10, 2017 ... Department of Chemical Engineering, Institute of Chemical Technology, Matunga (E), ... study for the synthesis of butyl caprylate in presence of bio-catalyst. ..... −1 with Thermomyces lanuginosus lipase.26 The relation.

Tea: age-old beverage as an effective cancer chemopreventive agent

Directory of Open Access Journals (Sweden)

Jasmine George

2011-12-01

Full Text Available Cancer is the major public health problem, causing approximately 7 million deaths every year worldwide. The existing treatment approaches and surgical techniques have not been able to cope effectively with this dreaded disease. Because of this, the concept of chemoprevention is now considered a valid approach to reduce the incidence of cancer. There is convincing epidemiological and experimental evidence to show that dietary polyphenolic plant-derived compounds have cancer preventive properties. Based on evidence from in vitro, in vivo data and epidemiological studies, tea has received considerable attention over recent years for reducing the risk of several cancers. Much of the cancer preventive effects of tea, and in particular green tea, appear to be mediated by the polyphenols they contain. In addition to inhibiting mutagenesis and proliferation, tea is relatively non-toxic, is low cost, and can be taken orally or as a part of the daily diet. Therefore it is logical that future clinical studies should focus on examining the efficacy of tea and its active constituents, such as epigallocatechin- 3-gallate (EGCG and theaflavins (TFs, in chemoprevention as an alternative to pharmacological agents. In this review, we address the use of tea and its constituents for the prevention and treatment of cancer. Further mechanistic and dose-response studies will help us to understand the effects of tea consumption on human carcinogenesis.

Salicylic acid metabolites and derivatives inhibit CDK activity: Novel insights into aspirin's chemopreventive effects against colorectal cancer

Science.gov (United States)

Dachineni, Rakesh; Kumar, D. Ramesh; Callegari, Eduardo; Kesharwani, Siddharth S.; Sankaranarayanan, Ranjini; Seefeldt, Teresa; Tummala, Hemachand; Bhat, G. Jayarama

2017-01-01

Aspirin's potential as a drug continues to be evaluated for the prevention of colorectal cancer (CRC). Although multiple targets for aspirin and its metabolite, salicylic acid, have been identified, no unifying mechanism has been proposed to clearly explain its chemopreventive effects. Our goal here was to investigate the ability of salicylic acid metabolites, known to be generated through cytochrome P450 (CYP450) enzymes, and its derivatives as cyclin dependent kinase (CDK) inhibitors to gain new insights into aspirin's chemopreventive actions. Using in vitro kinase assays, for the first time, we demonstrate that salicylic acid metabolites, 2,3-dihydroxy-benzoic acid (2,3-DHBA) and 2,5-dihydroxybenzoic acid (2,5-DHBA), as well as derivatives 2,4-dihydroxybenzoic acid (2,4-DHBA), 2,6-dihydroxybenzoic acid (2,6-DHBA), inhibited CDK1 enzyme activity. 2,3-DHBA and 2,6-DHBA did not inhibit CDK2 and 4; however, both inhibited CDK-6 activity. Interestingly, another derivative, 2,4,6-trihydroxybenzoic acid (2,4,6-THBA) was highly effective in inhibiting CDK1, 2, 4 and 6 activity. Molecular docking studies showed that these compounds potentially interact with CDK1. Immunoblotting experiments showed that aspirin acetylated CDK1, and pre-incubation with salicylic acid and its derivatives prevented aspirin-mediated CDK1 acetylation, which supported the data obtained from molecular docking studies. We suggest that intracellularly generated salicylic acid metabolites through CYP450 enzymes within the colonic epithelial cells, or the salicylic acid metabolites generated by gut microflora may significantly contribute to the preferential chemopreventive effect of aspirin against CRC through inhibition of CDKs. This novel hypothesis and mechanism of action in aspirin's chemopreventive effects opens a new area for future research. In addition, structural modification to salicylic acid derivatives may prove useful in the development of novel CDK inhibitors in cancer prevention and

Chemopreventive agents attenuate rapid inhibition of gap junctional intercellular communication induced by environmental toxicants

Czech Academy of Sciences Publication Activity Database

Babica, Pavel; Čtveráčková, Lucie; Lenčešová, Zuzana; Trosko, J. E.; Upham, B. L.

2016-01-01

Roč. 68, č. 5 (2016), s. 827-837 ISSN 0163-5581 R&D Projects: GA MŠk LH12034 Institutional support: RVO:67985939 Keywords : gap junctional intercellular communication * chemopreventive agents * environmental toxicants Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 2.447, year: 2016

Chemoprevention of Lung Cancer: Prospects and Disappointments in Human Clinical Trials

Directory of Open Access Journals (Sweden)

William N. Rom

2013-01-01

Full Text Available Decreasing the risk of lung cancer, or preventing its development in high-risk individuals, would have a huge impact on public health. The most effective means to decrease lung cancer incidence is to eliminate exposure to carcinogens. However, with recent advances in the understanding of pulmonary carcinogenesis and the identification of intermediate biomarkers, the prospects for the field of chemoprevention research have improved dramatically. Here we review the most recent research in lung cancer chemoprevention—focusing on those agents that have been investigated in human clinical trials. These agents fall into three major categories. First, oxidative stress plays an important role in pulmonary carcinogenesis; and therefore, antioxidants (including vitamins, selenium, green tea extracts, and isothiocyanates may be particularly effective in preventing the development of lung cancer. Second, inflammation is increasingly accepted as a crucial factor in carcinogenesis, and many investigators have focused on anti-inflammatory agents, such as glucocorticoids, NSAIDs, statins, and PPARγ agonists. Finally, the PI3K/AKT/mTOR pathway is recognized to play a central role in tobacco-induced carcinogenesis, and inhibitors of this pathway, including myoinositol and metformin, are promising agents for lung cancer prevention. Successful chemoprevention will likely require targeting of multiple pathways to carcinogenesis—both to minimize toxicity and maximize efficacy.

Intrinsic fluorescence biomarkers in cells treated with chemopreventive drugs

Science.gov (United States)

Kirkpatrick, Nathaniel D.; Brands, William R.; Zou, Changping; Brewer, Molly A.; Utzinger, Urs

2005-03-01

Non-invasive monitoring of cellular metabolism offers promising insights into areas ranging from biomarkers for drug activity to cancer diagnosis. Fluorescence spectroscopy can be utilized in order to exploit endogenous fluorophores, typically metabolic co-factors nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD), and estimate the redox status of the sample. Fluorescence spectroscopy was applied to follow metabolic changes in epithelial ovarian cells as well as bladder epithelial cancer cells during treatment with a chemopreventive drug that initiates cellular quiescence. Fluorescence signals consistent with NADH, FAD, and tryptophan were measured to monitor cellular activity, redox status, and protein content. Cells were treated with varying concentrations of N-4-(hydroxyphenyl) retinamide (4-HPR) and measured in a stable environment with a sensitive fluorescence spectrometer. A subset of measurements was completed on a low concentration of cells to demonstrate feasibility for medical application such as in bladder or ovary washes. Results suggest that all of the cells responded with similar dose dependence but started at different estimated redox ratio baseline levels correlating with cell cycle, growth inhibition, and apoptosis assays. NADH and tryptophan related fluorescence changed significantly while FAD related fluorescence remained unaltered. Fluorescence data collected from approximately 1000 - 2000 cells, comparable to a bladder or ovary wash, was measurable and useful for future experiments. This study suggests that future intrinsic biomarker measurements may need to be most sensitive to changes in NADH and tryptophan related fluorescence while using FAD related fluorescence to help estimate the baseline redox ratio and predict response to chemopreventive agents.

Double-Balloon-Assisted n-Butyl-2-Cyanoacrylate Embolization of Intrahepatic Arterioportal Shunt Prior to Chemoembolization of Hepatocellular Carcinoma

Energy Technology Data Exchange (ETDEWEB)

Takao, Hidemasa, E-mail: takaoh-tky@umin.ac.jp; Shibata, Eisuke; Ohtomo, Kuni [University of Tokyo, Department of Radiology, Graduate School of Medicine (Japan)

2016-10-15

A case of multiple hepatocellular carcinomas with a severe intrahepatic arterioportal shunt that was successfully embolized with n-butyl-2-cyanoacrylate with coaxial double-balloon occlusion prior to transcatheter arterial chemoembolization is presented. A proximal balloon positioned at the proper hepatic artery was used for flow control, and a coaxial microballoon, positioned in the closest of three arterial feeding branches to the arterioportal shunt, was used to control the delivery of n-butyl-2-cyanoacrylate. This coaxial double-balloon technique can prevent proximal embolization and distal migration of n-butyl-2-cyanoacrylate and enable precise control of the distribution of n-butyl-2-cyanoacrylate. It could also be applicable to n-butyl-2-cyanoacrylate embolization for other than intrahepatic arterioportal shunt.

Anaerobic degradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA).

Science.gov (United States)

Finneran, K T; Lovley, D R

2001-05-01

The potential for anaerobic degradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) was investigated in laboratory incubations of sediments from a petroleum-contaminated aquifer and in aquatic sediments. The addition of humic substances (HS) stimulated the anaerobic degradation of MTBE in aquifer sediments in which Fe(III) was available as an electron acceptor. This is attributed to the fact that HS and other extracellular quinones can stimulate the activity of Fe(III)-reducing microorganisms by acting as an electron shuttle between Fe(III)-reducing microorganisms and insoluble Fe(III) oxides. MTBE was not degraded in aquifer sediments without Fe(III) and HS. [14C]-MTBE added to aquatic sediments adapted for anaerobic MTBE degradation was converted to 14CO2 in the presence or absence of HS or the HS analog, anthraquione-2,6-disulfonate. Unamended aquatic sediments produced 14CH4 as well as 14CO2 from [14C]-MTBE. The aquatic sediments also rapidly consumed TBA under anaerobic conditions and converted [14C]-TBA to 14CH4 and 14CO2. An adaptation period of ca. 250-300 days was required prior to the most rapid anaerobic MTBE degradation in both sediment types, whereas TBA was metabolized in the aquatic sediments without a lag. These results demonstrate that, under the appropriate conditions, MTBE and TBA can be degraded in the absence of oxygen. This suggests that it may be possible to design strategies for the anaerobic remediation of MTBE in petroleum-contaminated subsurface environments.

Stereosequence distributions of poly(t-butyl methacrylate)s prepared with butyllithium

International Nuclear Information System (INIS)

Suzuki, Toshimitsu; Yamada, Osamu; Watanabe, Yoshihisa; Takegami, Yoshinobu

1982-01-01

13 C NMR spectra of poly(t-butyl methacrylate)s (PBMA) prepared with butyl-lithium (n-BuLi) were studied. Methylene carbon resonances appeared as five overlapped peaks, which were interpreted as a combination of hexad stereosequence distributions. The stereosequence distribution of PBMA prepared with n-BuLi at -78 0 C obeyed the first order Markov chain model even polymerized in tetrahydrofuran (THF). Syndiotactic PBMA was obtained with azobisisobutyronitrile (AIBN) as the initiator, and the stereosequence distribution of this polymer agreed well with Bernoullian statistics. (author)

27 CFR 21.101 - tert-Butyl alcohol.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false tert-Butyl alcohol. 21.101 Section 21.101 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21...

27 CFR 21.100 - n-Butyl alcohol.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false n-Butyl alcohol. 21.100 Section 21.100 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21...

A Chemopreventive Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress

National Research Council Canada - National Science Library

Hakim, Iman

2004-01-01

.... We are conducting a 6-month randomized, controlled, double-blinded chemopreventive trial in a group of COPD subjects who are being randomized to green or black tea preparations or a control intervention (matching placebo...

A Chemopreventive Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress

National Research Council Canada - National Science Library

Hakim, Iman A

2006-01-01

.... We are conducting a 6-month randomized, controlled, double-blinded chemopreventive trial in a group of COPD subjects who are being randomized to green or black tea preparations or a control intervention (matching placebo...

A Chemoprevention Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress

National Research Council Canada - National Science Library

Hakim, Iman A

2005-01-01

.... We are conducting a 6-month randomized, controlled, double-blinded chemopreventive trial in a group of COPD subjects who are being randomized to green or black tea preparations or a control intervention (matching placebo...

A Chemoprevention Trial to Study the Effects of High Tea Consumption on Smoking-Related Oxidative Stress

National Research Council Canada - National Science Library

Hakim, Iman A

2008-01-01

.... We are conducting a 6-month randomized controlled double-blinded chemopreventive trial in a group of COPD subjects who are being randomized to green or black tea preparations or a control intervention (matching placebo...

Polymerization behavior of butyl bis(hydroxymethyl)phosphine oxide ...

Indian Academy of Sciences (India)

lenovo

Polymerization behavior of butyl bis(hydroxymethyl)phosphine oxide: Phosphorus containing polyethers for. Li‒ion conductivities. Heeralal Vignesh Babu, Billakanti Srinivas and Krishnamurthi Muralidharan*. School of Chemistry, University of Hyderabad, Hyderabad - 500046, India. Table of Contents. TGA plots of SPE2.

Reverse screening methods to search for the protein targets of chemopreventive compounds

Science.gov (United States)

Huang, Hongbin; Zhang, Guigui; Zhou, Yuquan; Lin, Chenru; Chen, Suling; Lin, Yutong; Mai, Shangkang; Huang, Zunnan

2018-05-01

This article is a systematic review of reverse screening methods used to search for the protein targets of chemopreventive compounds or drugs. Typical chemopreventive compounds include components of traditional Chinese medicine, natural compounds and Food and Drug Administration (FDA)-approved drugs. Such compounds are somewhat selective but are predisposed to bind multiple protein targets distributed throughout diverse signaling pathways in human cells. In contrast to conventional virtual screening, which identifies the ligands of a targeted protein from a compound database, reverse screening is used to identify the potential targets or unintended targets of a given compound from a large number of receptors by examining their known ligands or crystal structures. This method, also known as in silico or computational target fishing, is highly valuable for discovering the target receptors of query molecules from terrestrial or marine natural products, exploring the molecular mechanisms of chemopreventive compounds, finding alternative indications of existing drugs by drug repositioning, and detecting adverse drug reactions and drug toxicity. Reverse screening can be divided into three major groups: shape screening, pharmacophore screening and reverse docking. Several large software packages, such as Schrödinger and Discovery Studio; typical software/network services such as ChemMapper, PharmMapper, idTarget and INVDOCK; and practical databases of known target ligands and receptor crystal structures, such as ChEMBL, BindingDB and the Protein Data Bank (PDB), are available for use in these computational methods. Different programs, online services and databases have different applications and constraints. Here, we conducted a systematic analysis and multilevel classification of the computational programs, online services and compound libraries available for shape screening, pharmacophore screening and reverse docking to enable non-specialist users to quickly learn and

Occurrence and potential crop uptake of emerging contaminants and related compounds in an agricultural irrigation network.

Science.gov (United States)

Calderón-Preciado, Diana; Matamoros, Víctor; Bayona, Josep M

2011-12-15

Emerging contaminants have received much attention in recent years due to their presence in surface waters, but little attention has been paid to their occurrence in agricultural irrigation waters. This study investigated the occurrence of these compounds in an agricultural irrigation network in northeastern Spain and, for the first time, using two plant uptake models, estimated the concentration of selected micropollutants in crops. The concentration of micropollutants in agricultural irrigation waters ranged from 10 to 5130 ng L(-1) and exhibited some attenuation over the course of the irrigation network. Bromoform, chloroform, diclofenac, caffeine, ibuprofen, naproxen, methyl dihydrojasmonate, galaxolide, butylated hydroxytoluene, and butylated hydroxyanisole were the most abundant contaminants (>200 ng L(-1), on average). The estimated concentration of micropollutants in crops ranged from contaminants detected). Further studies are needed to determine the health implications that the presence of these compounds in fruit and vegetables may have for consumers. Copyright © 2011 Elsevier B.V. All rights reserved.

[Food additives as a cause of medical symptoms: relationship shown between sulfites and asthma and anaphylaxis; results of a literature review].

Science.gov (United States)

Reus, K E; Houben, G F; Stam, M; Dubois, A E

2000-09-16

To determine if a causal connection exists between food additives and various medical complaints. Literature study. Medline over the period January 1966-January 1999 was searched for articles on the following substances not containing protein and lactose: monosodium glutamate (MSG), sulfites, azo-dyes (tartrazine, sunset yellow, azorubin, amarant, cochineal red), benzoates, sorbates, butylated hydroxyanisole/butylated hydroxytoluene (BHA/BHT), parabens, cinnamon and vanilla, in combination with key words regarding food and side effects. Of those studies purporting to demonstrate an effect, only double-blind randomized placebo-controlled studies with oral challenge were assessed further, unless the complaint was anaphylaxis. Of studies not demonstrating an effect the design was assessed. Only for sulfites as causative agents of asthma and anaphylaxis, methodologically adequate studies demonstrating a causal connection could be found. For azo-dyes, benzoates, MSG, sorbates and BHA/BHT, no link with medical symptoms was demonstrable. For parabens, cinnamon and vanilla there were insufficient or inadequate data to justify a conclusion.

Research into the functional components and antioxidant activities of North China rice wine (Ji Mo Lao Jiu).

Science.gov (United States)

He, Shuai; Mao, Xiangzhao; Liu, Pei; Lin, Hong; Du, Zuyuan; Lv, Ning; Han, Jichen; Qiu, Cuifang

2013-07-01

Over the last decade, considerable experimental evidence has supported the view that grape wine and South China rice wine are rich in diverse nutrients and have powerful antioxidant activity. However, little research has been carried out for North China rice wine, of which Ji Mo Lao Jiu (JMLJ) is the outstanding representative. In this study, the functional components and antioxidant activity of JMLJ were investigated. Twenty-eight free amino acids were found in JMLJ, much more than that previously reported in other Chinese rice wines (16-21). Functional oligosaccharides (5290.222 mg/L), total phenols (722.431 ± 10.970 mg/L), and mineral elements (9) were rich in JMLJ. When compared with synthetic antioxidants, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), JMLJ showed effective 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging and reducing capacity. The results of this study lay the foundation for promoting the utilization of JMLJ and the development of North China rice wine in the food industry.

Beyond COX-1: the effects of aspirin on platelet biology and potential mechanisms of chemoprevention.

Science.gov (United States)

Ornelas, Argentina; Zacharias-Millward, Niki; Menter, David G; Davis, Jennifer S; Lichtenberger, Lenard; Hawke, David; Hawk, Ernest; Vilar, Eduardo; Bhattacharya, Pratip; Millward, Steven

2017-06-01

After more than a century, aspirin remains one of the most commonly used drugs in western medicine. Although mainly used for its anti-thrombotic, anti-pyretic, and analgesic properties, a multitude of clinical studies have provided convincing evidence that regular, low-dose aspirin use dramatically lowers the risk of cancer. These observations coincide with recent studies showing a functional relationship between platelets and tumors, suggesting that aspirin's chemopreventive properties may result, in part, from direct modulation of platelet biology and biochemistry. Here, we present a review of the biochemistry and pharmacology of aspirin with particular emphasis on its cyclooxygenase-dependent and cyclooxygenase-independent effects in platelets. We also correlate the results of proteomic-based studies of aspirin acetylation in eukaryotic cells with recent developments in platelet proteomics to identify non-cyclooxygenase targets of aspirin-mediated acetylation in platelets that may play a role in its chemopreventive mechanism.

Subchronic toxicity studies of t-butyl alcohol in rats and mice.

Science.gov (United States)

Lindamood, C; Farnell, D R; Giles, H D; Prejean, J D; Collins, J J; Takahashi, K; Maronpot, R R

1992-07-01

The purpose of this study was to evaluate the toxicity of t-butyl alcohol, an important commodity chemical, an additive to unleaded gasoline, and a contaminant of drinking water. Ninety-day toxicity studies were conducted in B6C3F1 mice and Fischer 344 (F344) rats of both sexes using dosed water. Dose levels of t-butyl alcohol were 0, 0.25, 0.5, 1, 2, and 4% (w/v). Lethality was observed at the 4% level of both sexes and species. Weight-gain depression was present in all dose levels of male rats; 4% female rats; 1, 2, and 4% male mice; and 2 and 4% female mice. Water consumption was increased at lower dose levels in male rats and decreased in the higher dose levels of both sexes of rats and female mice. Clinical signs in rats were ataxia in both sexes and hypoactivity in males. Clinical signs in mice were ataxia, abnormal posture, and hypoactivity. In rats, urine volumes were reduced, in association with crystalluria. Gross lesions at necropsy were urinary tract calculi, renal pelvic and ureteral dilatation, and thickening of the urinary bladder mucosa. Microscopic lesions were hyperplasia of transitional epithelia and inflammation of the urinary bladder. In male rats treated with t-butyl alcohol, microscopic renal changes were suggestive of alpha-2 mu-globulin nephropathy. No-effect levels for the urinary tract lesions were 1% in male rats and mice (803.7 mg/kg/day for the male rats and 1565.8 mg/kg/day for the male mice) and 2% in female rats and mice (1451.5 mg/kg/day for the female rats and 4362.9 mg/kg/day for the female mice). The results indicate that in rodents the urinary tract is the target organ for t-butyl alcohol toxicity, and males are more sensitive to t-butyl alcohol toxicity than females.

Natural chemopreventive alternatives in oral cancer chemoprevention.

Science.gov (United States)

Scrobota, I; Bolfa, P; Filip, A G; Catoi, C; Alb, C; Pop, O; Tatomir, C; Baciut, G

2016-02-01

We studied the effect of grape seed extract Burgund Mare (BM) on oral carcinogenesis and compared it with that of curcumin (CU). Wistar rats were divided into six groups (n = 10): 4-nitro-quinoline-1-oxide (4NQO) oral carcinogenesis was induced to groups 1 - 5; groups 2 and 3 received BM and CU respectively during initiation and groups 4 and 5 BM and CU during post-initiation of carcinogenesis; group 6 represented the negative control group. Total malondialdehyde (MDA) and reduced glutathione (GSH) were assayed fluorometrically in oral tissue (gingival, jugal, palatal, lingual mucosa) and serum. Histopathological exam was performed and a dysplasia score given to each oral mucosal lesion. Ki67, cyclin D1, p63, Bcl2 and p53 were immunohistochemically evaluated. BM and CU reduced tissue MDA values elevated by 4NQO (P = 0.000). The difference between CU and BM effect was significant in the initiation (P = 0.02) but not in the post-initiation phase of carcinogenesis (P = 0.58). Tissue GSH levels decreased by 4NQO (P < 0.001) were not significantly modified by BM or CU. Serum MDA levels increased by 4NQO (P = 0.000) were significantly lowered by CU (P = 0.04) and BM (P = 0.04) during initiation and by CU during post-initiation of carcinogenesis (P = 0.01). CU was more potent than BM during post-initiation of carcinogenesis (P = 0.01). Serum GSH lowered by 4NQO (P = 0.55) was significantly decreased by BM and CU (P < 0.012), with no significant difference between groups receiving BM or CU. Moderate dysplasia was the most advanced dysplasia induced and gingival localization the most frequent. Both BM and CU lowered dysplasia scores, with BM being the most efficient during post-initiation of carcinogenesis (P = 0.001). Ki67, cyclin D1, p63, Bcl2 and p53 expression increased with dysplasia scores. BM showed chemopreventive properties during initiation and post-initiation of oral carcinogenesis, reducing local and general oxidative stress and the intensity of dysplasia

Efficacy of geraniol but not of β-ionone or their combination for the chemoprevention of rat colon carcinogenesis

Directory of Open Access Journals (Sweden)

A. Vieira

2011-06-01

Full Text Available β-ionone (βI, a cyclic isoprenoid, and geraniol (GO, an acyclic monoterpene, represent a promising class of dietary chemopreventive agents against cancer, whose combination could result in synergistic anticarcinogenic effects. The chemopreventive activities of βI and GO were evaluated individually or in combination during colon carcinogenesis induced by dimethylhydrazine in 48 3-week-old male Wistar rats (12 per group weighing 40-50 g. Animals were treated for 9 consecutive weeks with βI (16 mg/100 g body weight, GO (25 mg/100 g body weight, βI combined with GO or corn oil (control. Number of total aberrant crypt foci (ACF and of ACF ≥4 crypts in the distal colon was significantly lower in the GO group (66 ± 13 and 9 ± 2, respectively compared to control (102 ± 9 and 17 ± 3 and without differences in the βI (91 ± 11 and 14 ± 3 and βI+GO groups (96 ± 5 and 19 ± 2. Apoptosis level, identified by classical apoptosis morphological criteria, in the distal colon was significantly higher in the GO group (1.64 ± 0.06 apoptotic cells/mm² compared to control (0.91 ± 0.07 apoptotic cells/mm². The GO group presented a 0.7-fold reduction in Bcl-2 protein expression (Western blot compared to control. Colonic mucosa concentrations of βI and GO (gas chromatography/mass spectrometry were higher in the βI and GO groups, respectively, compared to the control and βI+GO groups. Therefore, GO, but not βI, represents a potential chemopreventive agent in colon carcinogenesis. Surprisingly, the combination of isoprenoids does not represent an efficient chemopreventive strategy.

Radiation crosslinking of poly(butyl acrylate) during polymerization and grafted copolymerization with Cr(III) crosslinked collagen

International Nuclear Information System (INIS)

Pietrucha, K.; Kroh, J.

1984-01-01

Enhanced crosslinking of synthetic polymer simultaneous with grafting and homopolymerization processes have been observed in irradiated leather tanned with Cr(III) and embedded with aqueous emulsions of butyl acrylate. Extent of poly(butyl acrylate) crosslinking during copolymerization was found to be approximately one order higher than in the case of radiation polymerization of butyl acrylate in emulsion. New method for isolation of grafted copolymer based on degradation of collagen has been developed. The extent of crosslinking was calculated from the swelling data. (author)

Chemoprevention of cancer: an ongoing saga.

Science.gov (United States)

Kellen, J A

1999-01-01

The trivial adage "an ounce of prevention..." is certainly appropriate in oncology; cancer has and continues to have an enormous impact on morbidity, suffering, socioeconomics and mortality. Curative therapy is elusive--cancer remains a mainly lethal disease, which makes the objective of prevention even more important and attractive. Sober estimates put the potentially avoidable or preventable cancers in the Western World at 80% (1): the effects of smoking and alcohol, being overweight, diet promiscuity and other lifestyle choices are well known, yet at the individual level, corrective measures are disappointingly ignored. Lately, this issue is being further weakened by our acceptance of inherited susceptibility--why change our habits and indulgences, if we can not escape our genetic destiny? However, there is a massive and growing amount of information on chemoprevention which needs to be carefully evaluated, in the hope that someday, we should be able to avoid or at least delay cancer by the use of natural or synthetic compounds which intervene in the early precancerous process.

EFFECTS OF STIMULATOR SUBSTANCES ON AEROBIC METHYL TERT-BUTYL ETHER BIODEGRADATION BY MICROBIAL CONSORTIUM

Directory of Open Access Journals (Sweden)

M. Farrokhi ، S. Ahmadizad

2009-04-01

Full Text Available In this study dissolved humic substances and yeast extract were tested in different concentrations for enhancing methyl tert-butyl ether mineralization by isolated microorganisms from a variety of sources. All experiments were conducted at a constant temperature of 25ºC. Vials of 50 mL and 125 mL volume sealed with Teflon-lined Mini-Nert caps was used for microcosm experiments. In all experiments 1% sodium azide were used as control. Samples of bacterial cultures that metabolize methyl tert-butyl ether have been analysed by direct GC analysis using flame ionization detector. Cultures able to metabolize have been found in activated sludge and soils. These microorganisms weregram-positive bacterium. An aerobic microbial consortium was enriched in laboratory for four months. Methyl tert-butyl ether has been shown to biodegrade under aerobic and co-metabolic conditions. A microbial consortium isolated from activated sludges was identified as Cocobacillus. The concentration of the initial attached biomass was about 0.11 g/L of dry weight. The maximum mineralization rate and beneficial effects of stimulator substances on aerobic biodegradation of methyl tert-butyl ether occurred with the culture by combined concentrations of 500 mg/L of yeast extract and 20 mg/L of peat humic growth support of microbial consortium within 216 h and in presence of high oxygen levels and well mixing conditions. It was shown that adding, peat humic and yeast extract together, had better stimulatory effect on methyl tert-butyl ether biodegradation. Results clearly showed a stimulatory effect on methyl tert-butyl ether consumption higher than 20%. Consortium was capable of degrading concentrations of ≤1000 mg/L, whereas concentrations of >1000 mg/L, were not degraded.

Comparison of the Effect of New Spice Freon Extracts Towards Ground Spices and Antioxidants for Improving the Quality of Bulgarian-Type Dry-Cured Sausage

Directory of Open Access Journals (Sweden)

Balev Dessislav Kostadinov

2017-03-01

Full Text Available Ground spices are a source of hazards for dry-fermented meat products. Since dry-cured sausages are not subjected to heat treatment, there is a high risk of microbial cross-contamination and physical impurities. The aim of this study was to determine effects of the replacement of 3 g/kg of ground black pepper (Piper nigrum L., and cumin (Cuminum cyminum with their aliquots of new freon extracts, and compare them with the effect of 0.2 g/kg antioxidant addition (taxifolin extract from Siberian larch (Larix sibirica Ledeb, rosemary (Rosmarinus officinalis L. extract, and butylated hydroxytoluene on sensory properties, color stability, proximate composition, free amino nitrogen and pH of Bulgarian-type dry-cured „Sudjuk“ sausages. The replacement of natural ground spices with aliquots of their extracts improved sensory properties and stabilized the color characteristics of the final product during 30 days of storage at 0–4°C. The addition of 0.2 g/kg rosemary extract was as effective as the addition of freon extracts on the overall assessment to the 14th day of the experiment. It was determined that the addition of antioxidants or spice extracts had no significant effect on proximate composition, pH, and free amino nitrogen accumulation of the “Sudjuk”. The addition of 0.2 g/kg, taxifolin or rosemary extracts and butylated hydroxytoluene was not so efficient in improving the sensory properties and color stabilization in comparison to the new freon spice extracts. The examined spice extracts can be successfully used to improve the quality of “Sudjuk” sausages.

Reaction of biscyclopentadienyl molybdendihalides with tert.-butyl hydroperoxide and its using for cyclohexene epoxidation

International Nuclear Information System (INIS)

Aleksandrov, Yu.A.; Fomin, V.M.; Kolmakov, A.O.

1983-01-01

As a result of reactions of biscyclopentadienyl molybden-dihalides (Cp 2 MoX 2 , X=Cl, Br or I) with tert.-butyl hydroperoxide, tert.-butylperoxides of biscyclopentadienyl molybdendichloride and-dibromide are synthesized for the first time, which are characterized by physico-chemical properties. Cyclohexene in the reaction mixture of Cp 2 MoX 2 with tert -butyl hydroperoxide is oxidated to form cyclohexene oxide, the reaction proceeding at a high rate and with a quantitative yield. Tert.-butylperoxide of biscyclopentadienyl molybdendihalide is responsible for the cyclohexene epoxidation reaction. The schemes for the mechanism of Cp 2 MoX 2 reactions with tert.-butyl hydroperoxide in the absence and presence of olefine are suggested

Atom transfer radical polymerization of n-butyl acrylate catalyzed by atom transfer radical polymerization of n-butyl acrylate catalyzed by

NARCIS (Netherlands)

Zhang, H.; Linde, van der R.

2002-01-01

The homogeneous atom transfer radical polymerization (ATRP) of n-butyl acrylate with CuBr/N-(n-hexyl)-2-pyridylmethanimine as a catalyst and ethyl 2-bromoisobutyrate as an initiator was investigated. The kinetic plots of ln([M]0/[M]) versus the reaction time for the ATRP systems in different

Third phase formation in the extraction of Th(NO_3)_4 by Tri-sec-butyl phosphate. A comparison with Tri-n-butyl phosphate

International Nuclear Information System (INIS)

Chandrasekar, Aditi; Suresh, A.; Sivaraman, N.

2017-01-01

Earlier studies carried out in our laboratory indicated that Tri-sec-butyl phosphate (TsBP) is a potential extractant for U/Th separation. Also, the third phase formation tendency of TsBP is lower compared to its isomers, Tri-n-butyl-phosphate (TBP) and Tri-iso-butyl phosphate (TiBP). In this context, the extraction and third phase formation behaviour of 1.1 M solutions of TiBP and TsBP in n-dodecane in the extraction of Th(IV) from 1 M HNO_3 at 303 K over a wide range of Th concentrations were investigated in the present study and the results are compared with the literature data on TBP system. Concentrations of Th(IV) and HNO_3 loaded in the organic phase before third phase formation (biphasic region) as well as in third phase and diluent-rich phase after third phase formation (triphasic region) were measured as a function of equilibrium aqueous phase Th(IV) concentration. The density of loaded organic phase was also measured at various Th(IV) concentrations. The extraction profiles in the biphasic region indicated that extraction of Th(IV) by TBP is higher than that of TiBP which in turn is higher than that of TsBP. Extractant concentration in the diluent-rich phase and third phase was measured for the triphasic region.

Nanoencapsulation of pomegranate bioactive compounds for breast cancer chemoprevention.

Science.gov (United States)

Shirode, Amit B; Bharali, Dhruba J; Nallanthighal, Sameera; Coon, Justin K; Mousa, Shaker A; Reliene, Ramune

2015-01-01

Pomegranate polyphenols are potent antioxidants and chemopreventive agents but have low bioavailability and a short half-life. For example, punicalagin (PU), the major polyphenol in pomegranates, is not absorbed in its intact form but is hydrolyzed to ellagic acid (EA) moieties and rapidly metabolized into short-lived metabolites of EA. We hypothesized that encapsulation of pomegranate polyphenols into biodegradable sustained release nanoparticles (NPs) may circumvent these limitations. We describe here the development, characterization, and bioactivity assessment of novel formulations of poly(D,L-lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) NPs loaded with pomegranate extract (PE) or individual polyphenols such as PU or EA. Monodispersed, spherical 150-200 nm average diameter NPs were prepared by the double emulsion-solvent evaporation method. Uptake of Alexa Fluor-488-labeled NPs was evaluated in MCF-7 breast cancer cells over a 24-hour time course. Confocal fluorescent microscopy revealed that PLGA-PEG NPs were efficiently taken up, and the uptake reached the maximum at 24 hours. In addition, we examined the antiproliferative effects of PE-, PU-, and/or EA-loaded NPs in MCF-7 and Hs578T breast cancer cells. We found that PE, PU, and EA nanoprototypes had a 2- to 12-fold enhanced effect on cell growth inhibition compared to their free counterparts, while void NPs did not affect cell growth. PU-NPs were the most potent nanoprototype of pomegranates. Thus, PU may be the polyphenol of choice for further chemoprevention studies with pomegranate nanoprototypes. These data demonstrate that nanotechnology-enabled delivery of pomegranate polyphenols enhances their anticancer effects in breast cancer cells. Thus, pomegranate polyphenols are promising agents for nanochemoprevention of breast cancer.

Radiation crosslinking of poly(butyl acrylate) during polymerization and grafted copolymerization with Cr(III) crosslinked collagen

International Nuclear Information System (INIS)

Pietrucha, K.; Kroh, J.

1986-01-01

Enhanced crosslinking of synthetic polymer simultaneously with grafting and homopolymerization processes has been observed in irradiated leather tanned with Cr(III) and embedded with aqueous emulsions of butyl acrylate. The extent of poly(butyl acrylate) crosslinking during copolymerization was found to be approximately one order higher than in the case of radiation polymerization of butyl acrylate in emulsion. A new method for isolation of grafted copolymer based on degradation of collagen has been developed. The extent of crosslinking was calculated from the swelling data. (author)

Method for determination of methyl tert-butyl ether and its degradation products in water

Science.gov (United States)

Church, C.D.; Isabelle, L.M.; Pankow, J.F.; Rose, D.L.; Tratnyek, P.G.

1997-01-01

An analytical method is described that can detect the major alkyl ether compounds that are used as gasoline oxygenates (methyl tert-butyl ether, MTBE; ethyl tert-butyl ether, ETBE; and tert-amyl methyl ether, TAME) and their most characteristic degradation products (tert-butyl alcohol, TBA; tert-butyl formate, TBF; and tert-amyl alcohol, TAA) in water at sub-ppb concentrations. The new method involves gas chromatography (GC) with direct aqueous injection (DAI) onto a polar column via a splitless injector, coupled with detection by mass spectrometry (MS). DAI-GC/MS gives excellent agreement with conventional purge-and-trap methods for MTBE over a wide range of environmentally relevant concentrations. The new method can also give simultaneous identification of polar compounds that might occur as degradation products of gasoline oxygenates, such as TBA, TBF, TAA, methyl acetate, and acetone. When the method was applied to effluent from a column microcosm prepared with core material from an urban site in New Jersey, conversion of MTBE to TBA was observed after a lag period of 35 days. However, to date, analyses of water samples from six field sites using the DAI-GC/MS method have not produced evidence for the expected products of in situ degradation of MTBE.An analytical method is described that can detect the major alkyl ether compounds that are used as gasoline oxygenates (methyl tert-butyl ether, MTBE; ethyl tert-butyl ether, ETBE; and tert-amyl methyl ether, TAME) and their most characteristic degradation products (tert-butyl alcohol, TBA; tert-butyl formate, TBF; and tert-amyl alcohol, TAA) in water at sub-ppb concentrations. The new method involves gas chromatography (GC) with direct aqueous injection (DAI) onto a polar column via a splitless injector, coupled with detection by mass spectrometry (MS). DAI-GC/MS gives excellent agreement with conventional purge-and-trap methods for MTBE over a wide range of environmentally relevant concentrations. The new method

Potential antioxidant Bauhinia Leaves and Bark kalbreyeri Harms: Contribution of your Flavonoids in this activity

International Nuclear Information System (INIS)

Ortiz, Heidy F; Sanchez, Wilmer F; Mendez A John; Murillo P, Elizabeth

2009-01-01

In this study the antioxidant and antitrosative capacity of the extracts and isolated flavonoids from the leaves and bark of Bauhinia kalbreyeri Harms (Cow Hoof. Fabaceae) was examinated. The extracts showed high antioxidant and antinitrosative functionality, while the flavonoids ability to capture metals and inhibit the NO. Significative differences were found among the extracts, and into those and the flavonoids fractions (p < 0.05). The antioxidant activity of the plant seems to be based in the whole phenolic derivatives. The results obtained indicate that the antioxidant potential of B. kalbreyeri is comparable with the Butylated Hydroxytoluene and the ascorbic acid used as antioxidants by the food and pharmaceutical industry.

Peroxidation of the dried thin film of lipid by high-energy alpha particles from a cyclotron

International Nuclear Information System (INIS)

Agarwal, S.; Chatterjee, S.N.

1984-01-01

High-energy α particles produced a dose-dependent linear increase in different lipid peroxidation products (e.g., malondialdehyde (MDA), conjugated dienes, and hydroperoxides) in the dried thin film state. An inverse dose-rate effect was observed when the dose rate was varied by changing either the α-particle fluence rate or the α-particle energy. The antioxidants α-tocopherol and butylated hydroxytoluene (BHT) suppressed the α-particle-induced lipid peroxidation in the dried thin film state, and in this respect α-tocopherol was found superior to BHT. It was found that α-tocopherol was equally efficient in inhibiting lipid peroxidations by α particles and ultraviolet light

Carcinogenesis

International Nuclear Information System (INIS)

Anon.

1976-01-01

Progress is reported on studies at the molecular, biochemical, and immunological level of carcinogenesis induced in mice by viruses, radiation, or environmental chemicals alone or in combinations. Emphasis was placed on the identification and assessments of cocarcinogens and studies on their mechanisms of action. Data are included on mechanisms of carcinogenesis in the liver, thyroid, Harderian glands, skin, and lungs. The effects of the food additive butylated hydroxytoluene (BHT), phenobarbitol, DDT, uv irradiation, the herbicide 3-amino-1,2,4-triazole(AT), the pituitary hormone prolactin, topically applied 8-methoxypsoralen (8-MOP), and benzo(a) pyrene(BaP) on tumor induction or enhancement were studied

Can transcriptomics provide insight into the underlying chemopreventive mechanisms of complex mixtures of phytochemicals in humans?

NARCIS (Netherlands)

Breda, van S.G.; Wilms, L.C.; Gaj, S.; Briedé, J.J.; Helsper, J.P.F.G.; Kleinjans, J.C.; Kok, de T.M.

2014-01-01

Blueberries contain relatively large amounts of different phytochemicals which are suggested to have chemopreventive properties, but little information is available on the underlying molecular modes of action. This study investigates whole genome gene expression changes in lymphocytes of 143 humans

Chemopreventive effect of artesunate in 1,2-dimethylhydrazine-induced rat colon carcinogenesis

Directory of Open Access Journals (Sweden)

Sazal Patyar

2017-01-01

Full Text Available Artesunate (ART is a semisynthetic derivative of artemisinin. Artemisinin and its derivatives have shown profound cytotoxicity and antitumor activity in addition to antimalarial activity in various studies. As the in vivo chemopreventive efficacy of ART in colon carcinogenesis has not been investigated so far, the aim of the current study was to study the chemopreventive effect of ART in 1,2-dimethylhydrazine (DMH-induced rat colon carcinogenesis. Animals were divided into four groups (n = 6: Group I - vehicle (1 mM ethylenediaminetetraacetic acid, Group II - DMH (20 mg/kg, Group III - DMH + 5-fluorouracil (81 mg/kg, Group IV - DMH + ART (6.7 mg/kg. After completion of 15 weeks of treatment, rats were sacrificed under ether anesthesia by cervical dislocation for assessment of lipid peroxidation (LPO, antioxidant status, average number of aberrant crypt foci (ACF, and cytokine levels. ART administration significantly decreased the average number of ACF/microscopic field. Similarly, LPO level was decreased and antioxidant activities were enhanced after ART treatment. ART decreased the levels of proinflammatory cytokines and induced apoptosis in the colons of DMH-treated rats. The results of this study suggest that ART has a beneficial effect against chemically induced colonic preneoplastic progression in rats.

Trial endpoints for drug approval in oncology: Chemoprevention.

Science.gov (United States)

Beitz, J

2001-04-01

As with other drugs, new drug applications for marketing approval of chemopreventive drugs must include data from adequate and well-controlled clinical trials that demonstrate effectiveness and safety for the intended use. This article summarizes the regulatory requirements for traditional marketing approval, as well as for approval under the accelerated approval regulations. Unlike traditional approval, accelerated approval is based on a surrogate endpoint that is reasonably likely to predict clinical benefit. Discussions with the Food and Drug Administration (FDA) regarding the validity of trial endpoints that may serve as surrogates for clinical benefit for accelerated approval should take place as early as possible in drug development. Meetings with the FDA to discuss these issues may be requested throughout the clinical development of a new drug.

Selenium Supranutrition: Are the Potential Benefits of Chemoprevention Outweighed by the Promotion of Diabetes and Insulin Resistance?

Science.gov (United States)

Rocourt, Caroline R. B.; Cheng, Wen-Hsing

2013-01-01

Selenium was considered a toxin until 1957, when this mineral was shown to be essential in the prevention of necrotic liver damage in rats. The hypothesis of selenium chemoprevention is principally formulated by the observations that cancer incidence is inversely associated with selenium status. However, recent clinical and epidemiological studies demonstrate a role for some selenoproteins in exacerbating or promoting other disease states, specifically type 2 diabetes, although other data support a role of selenium in stimulating insulin sensitivity. Therefore, it is clear that our understanding in the role of selenium in glucose metabolism and chemoprevention is inadequate and incomplete. Research exploring the role of selenium in individual healthcare is of upmost importance and possibly will help explain how selenium is a double-edged sword in the pathologies of chronic diseases. PMID:23603996

Synthesis of Highly Porous Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) Asymmetric Membranes

KAUST Repository

Xie, Yihui; Moreno Chaparro, Nicolas; Calo, Victor M.; Cheng, Hong; Hong, Pei-Ying; Sougrat, Rachid; Behzad, Ali Reza; Tayouo Djinsu, Russell; Nunes, Suzana Pereira

2016-01-01

For the first time, self-assembly and non-solvent induced phase separation was applied to polysulfone-based linear block copolymers, reaching mechanical stability much higher than other block copolymers membranes used in this method, which were mainly based on polystyrene blocks. Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) (PtBA30k-b-PSU14k-b-PtBA30k) with a low polydispersity of 1.4 was synthesized by combining step-growth condensation and RAFT polymerization. Various advanced electron microscopies revealed that PtBA30k-b-PSU14k-b-PtBA30k assembles into worm-like cylindrical micelles in DMAc and adopts a “flower-like” arrangement with the PSU central block forming the shell. Computational modeling described the mechanism of micelle formation and morphological transition. Asymmetric nanostructured membranes were obtained with a highly porous interconnected skin layer and a sublayer with finger-like macrovoids. Ultrafiltration tests confirmed a water permeance of 555 L m-2 h-1 bar-1 with molecular weight cut-off of 28 kg/mol. PtBA segments on the membrane surface were then hydrolyzed and complexed with metals, leading to cross-linking and enhancement of antibacterial capability.

Synthesis of Highly Porous Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) Asymmetric Membranes

KAUST Repository

Xie, Yihui

2016-03-24

For the first time, self-assembly and non-solvent induced phase separation was applied to polysulfone-based linear block copolymers, reaching mechanical stability much higher than other block copolymers membranes used in this method, which were mainly based on polystyrene blocks. Poly(tert-butyl acrylate)-b-polysulfone-b-poly(tert-butyl acrylate) (PtBA30k-b-PSU14k-b-PtBA30k) with a low polydispersity of 1.4 was synthesized by combining step-growth condensation and RAFT polymerization. Various advanced electron microscopies revealed that PtBA30k-b-PSU14k-b-PtBA30k assembles into worm-like cylindrical micelles in DMAc and adopts a “flower-like” arrangement with the PSU central block forming the shell. Computational modeling described the mechanism of micelle formation and morphological transition. Asymmetric nanostructured membranes were obtained with a highly porous interconnected skin layer and a sublayer with finger-like macrovoids. Ultrafiltration tests confirmed a water permeance of 555 L m-2 h-1 bar-1 with molecular weight cut-off of 28 kg/mol. PtBA segments on the membrane surface were then hydrolyzed and complexed with metals, leading to cross-linking and enhancement of antibacterial capability.

Metabolism of the fungicide Denmert (S-n-butyl S'-p-tert-butyl-benzyl N-3-pyridyldithiocarbonimidate, S-1358) and Denmert sulfoxides in liver enzyme systems

International Nuclear Information System (INIS)

Ohkawa, Hideo; Okihara, Yukiko; Miyamoto, Junshi

1976-01-01

On incubation with rat liver microsomes plus MADPH, Denmert (S-n-butyl S'-p-tert-butylbenzyl N-3-pyridyldithiocarbonimidate) underwent at least two different types of oxidation; hydroxylation and sulfoxidation. Hydroxylation of Denmert at the tert-butyl group was one of the major metabolic attacks in mammalian metabolism. Sulfoxidation of Denmert gave two isomers of Denmert sulfoxides which were intermediates in the metabolism and readily transformed into 2-(3'-pyridylimino)-4-carboxylthiazolidine (HM) in the presence of L-cysteine without enzymatic mediation. This type of conjugation with cysteine appears to be a new class of metabolic reactions in mammals. Denmert S-oxide showed increased fungicidal activity when assayed in liquid cultures, but not on plant leaves. (auth.)

Solvent-free sample preparation by headspace solid-phase microextraction applied to the tracing of n-butyl nitrite abuse.

Science.gov (United States)

Tytgat, J; Daenens, P

1996-01-01

The most common alkyl nitrites encountered in forensic toxicology are iso-butyl, n-butyl and iso-pentyl(amyl) nitrites. All have become popular as an aphrodisiac, especially among the homosexual population. Alkyl nitrites are a volatile and unstable group of compounds, which hydrolyse in aqueous matrices to the alcohol and nitrite ion. Here we describe a fast, clean and sensitive procedure for the detection of hydrolysed n-butyl nitrite in whole human blood using a new, solvent-free sampling technique, the headspace solid-phase micro-extraction (HSPME), combined with GC/FID analysis. Sample preparation was investigated using two different stationary phases (100 microns polydimethylsiloxane and 85 microns polyacrylate), coating a fused silica fibre. The effect of different sampling times at fixed temperatures was also studied. Our results demonstrate that the HSPME/GC/FID procedure allows tracing of n-butyl nitrite abuse and detects hydrolysed n-butyl nitrite, i.e., released n-butanol, in whole blood at the 1 ng/mL level.

Diisobutyl phthalate has comparable anti-androgenic effects to di-n-butyl phthalate in fetal rat testis

DEFF Research Database (Denmark)

Boberg, Julie; Petersen, Marta Axelstad; Vinggaard, Anne

2006-01-01

Phthalates are widely used as plasticizers in various consumer products and building materials. Some of the phthalates are known to interfere with male reproductive development in rats, and di-n-butyl phthalate (DBP), diethylhexyl phthalate (DEHP) and butyl benzyl phthalate (BBP) were recently...

Automated batch emulsion copolymerization of styrene and butyl acrylate

NARCIS (Netherlands)

Mballa Mballa, M.A.; Schubert, U.S.; Heuts, J.P.A.; Herk, van A.M.

2011-01-01

This article describes a method for carrying out emulsion copolymerization using an automated synthesizer. For this purpose, batch emulsion copolymerizations of styrene and butyl acrylate were investigated. The optimization of the polymerization system required tuning the liquid transfer method,

Chemoprevention of DMH-induced rat colon carcinoma initiation by combination administration of piroxicam and C-phycocyanin.

Science.gov (United States)

Saini, Manpreet Kaur; Vaiphei, Kim; Sanyal, Sankar Nath

2012-02-01

Cancer research illustrated that combinatorial studies can provide significant improvement in safety and effectiveness over the monotherapy regimens. A combination of two drugs may restrain precancerous colon polyps, opening a new possible opportunity for chemoprevention of colon cancer. In this context, chemopreventive efficacy of a combination regimen of C-phycocyanin, a biliprotein present in Spirulina platensis, a cyanobacterium, which is a selective cycloxygenase-2 (COX-2) inhibitor and piroxicam, a traditional non-steroidal anti-inflammatory drug was considered in 1,2 dimethylhyadrazine (DMH)-induced colon carcinogenesis in rats. Western blotting, immunohistochemistry, DNA fragmentation, fluorescent staining, PGE(2) enzyme immunoassay, and carrageenan-induced paw edema test were performed along with morphological and histological analysis. DMH treatment showed a rich presence of preneoplastic lesions such as multiple plaque lesions, aberrant crypt foci, and well-characterized dysplasia. These features were reduced with piroxicam and C-phycocyanin administration. The number of apoptotic cells was featured prominently in all the groups compared with DMH. DMH treatment revealed intact high molecular weight genomic DNA with no signs of laddering/DNA fragmentation while it was noticeable significantly in control and DMH + piroxicam + C-phycocyanin. DMH group showed highest COX-2 expression and PGE(2) level in comparison with other groups. Doses of piroxicam and C-phycocyanin used in the present study were established at an anti-inflammatory range. A combination regimen of piroxicam and C-phycocyanin, rather than individually has the much greater potential for reduction of DMH-induced colon cancer development and COX-2 being the prime possible target in such chemoprevention.

Molecular recognition study of ethosuximide by the supramolecular probe, p-t-butyl calix(8)arene

Energy Technology Data Exchange (ETDEWEB)

Meenakshi, C., E-mail: geethu.laxi@gmail.com [Department of Chemistry, Shri Meenakshi Government College for Women (Autonomous), Madurai 625002 (India); Sangeetha, P.; Ramakrishnan, V. [Department of Laser Studies, School of Physics, Madurai Kamaraj University, Madurai 625021 (India)

2013-06-15

The supramolecule, p-t-Butyl calix(8)arene, forms inclusion complex with the antiseizure drug molecule, ethosuximide. This feature is explained on the basis of optical absorption spectroscopy. Here p-t-Butyl calix(8)arene is the host molecule and ethosuximide is the guest molecule. The stoichiometry of the host–guest complex and the binding constant has been determined using Benesi–Hildebrand plot. Based on the result obtained the structure of the inclusion complex has been proposed. -- Highlights: ► Third generation supramolecule, t-butyl calix (8) arene, is used as a host molecule. ► Anti seizure drug molecule is used as a guest molecule. ► Inclusion complex is formed between the host and guest molecule.

In situ 1H NMR studies of high-temperature nitroxide-mediated polymerization of n-butyl acrylate

NARCIS (Netherlands)

Hlalele, L.; Klumperman, L.

2011-01-01

This paper presents results on the independence of the rate of polymerization of n-butyl acrylate (n-BA) toward initial concentration of the alkoxyamine initiator. The alkoxyamine, 2-methyl-2-[N-tert-butyl-N-(1-diethoxyphosphoryl-2,2-dimethylpropyl)aminooxy]propionic acid (MAMA-DEPN), was used to

Atomic Force Microscopy Based Thermal Lithography of Poly(tert-butyl acrylate) Block Copolymer Films for Bioconjugation

NARCIS (Netherlands)

Duvigneau, Joost; Schönherr, Holger; Vancso, Gyula J.

2008-01-01

In this paper, we report on the local thermal activation of thin polymer films for area-selective surface chemical modification on micrometer and nanometer length scales. The thermally induced activation of tert-butyl ester moieties in polystyrene-block-poly(tert-butyl acrylate) (PS-b-PtBA) block

Temperature effect on tert-butyl alcohol (TBA) biodegradation kinetics in hyporheic zone soils.

Science.gov (United States)

Greenwood, Mark H; Sims, Ronald C; McLean, Joan E; Doucette, William J

2007-09-19

Remediation of tert-butyl alcohol (TBA) in subsurface waters should be taken into consideration at reformulated gasoline contaminated sites since it is a biodegradation intermediate of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-butyl formate (TBF). The effect of temperature on TBA biodegradation has not been not been published in the literature. Biodegradation of [U 14C] TBA was determined using hyporheic zone soil microcosms. First order mineralization rate constants of TBA at 5 degrees C, 15 degrees C and 25 degrees C were 7.84 +/- 0.14 x 10-3, 9.07 +/- 0.09 x 10-3, and 15.3 +/- 0.3 x 10-3 days-1, respectively (or 2.86 +/- 0.05, 3.31 +/- 0.03, 5.60 +/- 0.14 years-1, respectively). Temperature had a statistically significant effect on the mineralization rates and was modelled using the Arrhenius equation with frequency factor (A) and activation energy (Ea) of 154 day-1 and 23,006 mol/J, respectively. Results of this study are the first to determine mineralization rates of TBA for different temperatures. The kinetic rates determined in this study can be used in groundwater fate and transport modelling of TBA at the Ronan, MT site and provide an estimate for TBA removal at other similar shallow aquifer sites and hyporheic zones as a function of seasonal change in temperature.

Higher levels of ethyl paraben and butyl paraben in rat amniotic fluid than in maternal plasma after subcutaneous administration

DEFF Research Database (Denmark)

Frederiksen, Hanne; Taxvig, Camilla; Hass, Ulla

2008-01-01

to obtain more knowledge about the distribution of ethyl paraben and butyl paraben in pregnant rats and pups after perinatal exposure, the presented study was designed. The data show response and distribution of ethyl paraben and butyl paraben in maternal rat plasma, pools of amniotic fluids, placenta......, whole-body fetuses, and in fetal liver after dosing of dams with 100, 200, and 400 mg/kg body weight (bw)/day from gestational day 7 to 21. After cesarean section of dams, the fluids and tissues were collected, deconjugated, and purified by solid-phase extraction, and ethyl paraben and butyl paraben...... were analyzed by liquid chromatography-tandem mass spectrometry. Markedly higher levels of ethyl paraben compared to butyl paraben were found in all fluids and tissues. Both ethyl paraben and butyl paraben in maternal plasma, livers, and whole-body tissues from fetus seemed to be saturated after dosing...

Oleuropein and Cancer Chemoprevention: The Link is Hot

Directory of Open Access Journals (Sweden)

Ammad Ahmad Farooqi

2017-04-01

Full Text Available Cancer comprises a collection of related diseases characterized by the existence of altered cellular pathways resulting in an abnormal tendency for uncontrolled growth. A broad spectrum, coordinated, and personalized approach focused on targeting diverse oncogenic pathways with low toxicity and economic natural compounds can provide a real benefit as a chemopreventive and/or treatment of this complex disease. Oleuropein, a bioactive phenolic compound mainly present in olive oil and other natural sources, has been reported to modulate several oncogenic signalling pathways. This review presents and critically discusses the available literature about the anticancer and onco-suppressive activity of oleuropein and the underlying molecular mechanisms implicated in the anticarcinogenic and therapeutic effects. The existence of limitations and the promising perspectives of research on this phenolic compound are also critically analyzed and discussed.

Estimation of the fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample

DEFF Research Database (Denmark)

Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye

2008-01-01

The fraction of biologically active methyl tert-butyl ether degraders in reactors is just as important for prediction of removal rates as knowledge of the kinetic parameters. The fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample, taken from a packed...... bed reactor, was determined using a batch kinetic based approach. The procedure involved modeling of methyl tert-butyl ether removal rates from batch experiments followed by parameter estimations. It was estimated to be 5-14% (w/w) of the measured volatile suspended solids concentration in the reactor....

Chemopreventive effect of Cynodon dactylon (L.) Pers. extract against DMH-induced colon carcinogenesis in experimental animals.

Science.gov (United States)

Albert-Baskar, Arul; Ignacimuthu, Savarimuthu

2010-07-01

The present study was aimed at evaluating the chemopreventive property of Cynodon dactylon. The antioxidant, antiproliferative and apoptotic potentials of the plant were investigated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, nitric oxide radical scavenging activity (NO(-)) and MTT assay on four cancer cell lines (COLO 320 DM, MCH-7, AGS, A549) and a normal cell line (VERO). In vivo chemopreventive property of the plant extract was studied in DMH-induced colon carcinogenesis. The methanolic extract of C. dactylon was found to be antiproliferative and antioxidative at lower concentrations and induced apoptotic cell death in COLO 320 DM cells. Treatment with methanolic extract of C. dactylon increased the levels of antioxidant enzymes and reduced the number of dysplastic crypts in DMH-induced colon of albino rats. The present investigation revealed the anticancer potential of methanolic extract of C. dactylon in COLO 320 DM cells and experimentally induced colon carcinogenesis in rats.

76 FR 5696 - Fluazifop-P-butyl; Pesticide Tolerances

Science.gov (United States)

2011-02-02

...: This regulation establishes tolerances for residues of fluazifop-P-butyl in or on multiple commodities... based on maternal body weight gain decrement during GD 7- 16. Incidental oral intermediate- NOAEL= 0.74....0 and 2% at 200 mg dose.) mg/kg/day based on fetal UFA = 10x weight decrement, UFH = 10x hydroureter...

Third phase formation in the extraction of Th(NO{sub 3}){sub 4} by Tri-sec-butyl phosphate. A comparison with Tri-n-butyl phosphate

Energy Technology Data Exchange (ETDEWEB)

Chandrasekar, Aditi; Suresh, A.; Sivaraman, N. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Chemistry Group

2017-06-01

Earlier studies carried out in our laboratory indicated that Tri-sec-butyl phosphate (TsBP) is a potential extractant for U/Th separation. Also, the third phase formation tendency of TsBP is lower compared to its isomers, Tri-n-butyl-phosphate (TBP) and Tri-iso-butyl phosphate (TiBP). In this context, the extraction and third phase formation behaviour of 1.1 M solutions of TiBP and TsBP in n-dodecane in the extraction of Th(IV) from 1 M HNO{sub 3} at 303 K over a wide range of Th concentrations were investigated in the present study and the results are compared with the literature data on TBP system. Concentrations of Th(IV) and HNO{sub 3} loaded in the organic phase before third phase formation (biphasic region) as well as in third phase and diluent-rich phase after third phase formation (triphasic region) were measured as a function of equilibrium aqueous phase Th(IV) concentration. The density of loaded organic phase was also measured at various Th(IV) concentrations. The extraction profiles in the biphasic region indicated that extraction of Th(IV) by TBP is higher than that of TiBP which in turn is higher than that of TsBP. Extractant concentration in the diluent-rich phase and third phase was measured for the triphasic region.

Endoscopic application of n-butyl-2-cyanoacrylate on esophagojejunal anastomotic leak: a case report

Directory of Open Access Journals (Sweden)

Angelopoulos Stamatis

2011-03-01

Full Text Available Abstract Introduction This case report describes an esophagojejunal anastomotic leak following total gastrectomy for gastric cancer. The leak was treated successfully with endoscopic application of n-butyl-2-cyanoacrylate. This is the first case report on the endoscopic application of cyanoacrylate alone for the treatment of an anastomotic leak. Case presentation This report describes a case of a 68-year-old Caucasian man who underwent surgery for gastric cancer. He underwent total gastrectomy and esophagojejunal anastomosis with Roux-en-Y anastomosis plus transverse colectomy. An anastomotic leak was treated conservatively at first for a total of three weeks. However, the leak persisted; therefore, the decision was made to apply topical endoscopic n-butyl-2-cyanoacrylate. Conclusion The endoscopic application of n-butyl-2-cyanoacrylate alone can be used successfully to treat esophagojejunal anastomotic leakage.

A green-emitting CdSe/Poly(butyl acrylate) nanocomposite

NARCIS (Netherlands)

Peres, M.; Costa, L.C.; Neves, A.; Soares, M.J.; Monteiro, T.; Carvalho Esteves, de A.C.; Barros-Timmons, A.M.M.V.; Trindade, T.; Kholkin, A.; Alves, E.

2005-01-01

CdSe/poly(butyl acrylate) nanocomposites were synthesized by in situ miniemulsion polymerization. The hybrid nanomaterial is very stable and presents a bright green photoluminescence at 2.29 eV under ultraviolet excitation. With the excitation conditions used the intensity of the emission band keeps

Effect of di-butyl phosphate on flash point of PUREX solvent

International Nuclear Information System (INIS)

Srivastav, Ravi Kant; Kumar, Shekhar; Balasubramonian, S.; Kamachi Mudali, U.; Natarajan, R.

2015-01-01

30% Tri-n-butyl phosphate (TBP) in a aliphatic diluent is used as a solvent for PUREX process. This diluent is essentially equivalent to commercial dodecane. The radiolytic and acidic degradation of TBP forms di-butyl phosphate (DBP) which is detrimental to the performance of the solvent during nuclear fuel reprocessing operations. To study the possible effect of DBP on the flashpoint of PUREX solvent, synthetic solutions were made by adding DBP and flashpoints of resultant mixtures were determined with an automatic flashpoint tester as per ASTM procedures. Experimental results indicated virtually no effect of DBP on flash point of PUREX solvent in the concentration ranges of 0-16 g/L DBP. (author)

On the viscosity of two 1-butyl-1-methylpyrrolidinium ionic liquids: effect of the temperature and pressure

DEFF Research Database (Denmark)

Gaciño, Félix M.; Comuñas, María J.P.; Regueira Muñiz, Teresa

2015-01-01

to measure viscosities as a function of temperature and pressure fortwo ionic liquids (ILs): 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphateand 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate.Besides, we have measured the flow curves at pressures up to 75 MPa and shear rates up...

Temperature influence on mixing properties of {ethyl tert-butyl ether (ETBE) + gasoline additives}

International Nuclear Information System (INIS)

Gonzalez-Olmos, R.; Iglesias, M.

2007-01-01

The densities and ultrasonic velocity of {ethyl tert-butyl ether (ETBE) + (benzene, toluene, ethylbenzene, isooctane, tert-butyl alcohol, and ethanol)} over the temperature range (288.15 to 323.15) K and atmospheric pressure, have been measured over the whole concentration range. The experimental excess volumes and deviation of isentropic compressibilities data have been analysed in terms of different theoretical models. The gathered data improve open literature related to gasoline additives, and help to understand the ETBE volumetric and acoustic trend into different chemical environment

In vitro chemopreventive properties of peptides released from quinoa (Chenopodium quinoa Willd.) protein under simulated gastrointestinal digestion.

Science.gov (United States)

Vilcacundo, Rubén; Miralles, Beatriz; Carrillo, Wilman; Hernández-Ledesma, Blanca

2018-03-01

Because of the continuous and direct interaction between the digestive tract and foods, dietary compounds represent an interesting source of chemopreventive agents for gastrointestinal health. In this study, the influence of a standardized static in vitro gastrointestinal digestion model on the release of peptides with chemopreventive potential from quinoa protein was investigated. Gastroduodenal digests and fractions collected by ultrafiltration were evaluated for their in plate oxygen radical absorbance capacity and in vitro colon cancer cell viability inhibitory activity. Highest effects were observed in the digests obtained during the intestinal phase, with fraction containing peptides 5kDa showing the greatest anti-cancer effects. Seventeen potential bioactive peptides derived from quinoa proteins have been identified. These proteins might be utilized as new ingredients in the development of functional foods or nutraceuticals with the aim of reducing oxidative stress-associated diseases, including cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative Evaluation of Different Co-Antioxidants on the Photochemical- and Functional-Stability of Epigallocatechin-3-gallate in Topical Creams Exposed to Simulated Sunlight

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Santo Scalia

2013-01-01

Full Text Available The catechin (−-epigallocatechin-3-gallate (EGCG exhibits high antioxidant activity and it has been reported to provide protection of the skin against damage induced by solar UV radiation. However, EGCG is highly unstable under sunlight. The present study aimed to compare the effectiveness of the co-antioxidant agents vitamin E, butylated hydroxytoluene, vitamin C and a-lipoic acid for their potential to protect the catechin from photochemical degradation. Model creams (oil-in-water emulsions containing EGCG (1%, w/w alone or combined with equimolar concentrations of co-antioxidant were exposed to a solar simulator at an irradiance corresponding to natural sunlight. Photodegradation was evaluated by HPLC-UV and HPLC-ESI-MS/MS. Addition of the co-antioxidants vitamin C and a-lipoic acid to the formulation significantly reduced the light-induced decomposition of EGCG from 76.9 ± 4.6% to 20.4 ± 2.7% and 12.6 ± 1.6%, respectively. Conversely, butylated hydroxytoluene had no effect (EGCG loss, 78.1 ± 4.6% and vitamin E enhanced the EGCG photolysis to 84.5 ± 3.4%. The functional stability of the catechin in the creams exposed to the solar simulator was also evaluated by measuring the in vitro antioxidant activity. Following irradiation, the reduction of the EGCG formulation antioxidant power was lower (21.8% than the extent of degradation (76.9%, suggesting the formation of photoproducts with antioxidant properties. The influence of the examined co-antioxidants on the functional stability of the catechin under simulated sunlight paralleled that measured for the EGCG photodecomposition, a-lipoic acid exerting the greatest stabilising effect (antioxidant activity decrease, 1.4%. These results demonstrated that a-lipoic acid is an effective co-antioxidant agent for the stabilization of EGCG in dermatological products for skin photoprotection.

Temperature effect on tert-butyl alcohol (TBA biodegradation kinetics in hyporheic zone soils

Directory of Open Access Journals (Sweden)

Sims Ronald C

2007-09-01

Full Text Available Abstract Background Remediation of tert-butyl alcohol (TBA in subsurface waters should be taken into consideration at reformulated gasoline contaminated sites since it is a biodegradation intermediate of methyl tert-butyl ether (MTBE, ethyl tert-butyl ether (ETBE, and tert-butyl formate (TBF. The effect of temperature on TBA biodegradation has not been not been published in the literature. Methods Biodegradation of [U 14C] TBA was determined using hyporheic zone soil microcosms. Results First order mineralization rate constants of TBA at 5°C, 15°C and 25°C were 7.84 ± 0.14 × 10-3, 9.07 ± 0.09 × 10-3, and 15.3 ± 0.3 × 10-3 days-1, respectively (or 2.86 ± 0.05, 3.31 ± 0.03, 5.60 ± 0.14 years-1, respectively. Temperature had a statistically significant effect on the mineralization rates and was modelled using the Arrhenius equation with frequency factor (A and activation energy (Ea of 154 day-1 and 23,006 mol/J, respectively. Conclusion Results of this study are the first to determine mineralization rates of TBA for different temperatures. The kinetic rates determined in this study can be used in groundwater fate and transport modelling of TBA at the Ronan, MT site and provide an estimate for TBA removal at other similar shallow aquifer sites and hyporheic zones as a function of seasonal change in temperature.

Evaluating the potential cancer chemopreventive efficacy of two different solvent extracts of Seriphidium herba-alba in vitro

Directory of Open Access Journals (Sweden)

Mahmoud Mohamed Mokhtar

2017-06-01

Full Text Available Cancer is the second leading cause of death world-wide. One of the most important medical practices of the 21st century is the chemoprevention of cancer. For a long history, it has been accepted that plants could prevent and exert suitable anti-carcinogenic effects for multiple types of cancers. Seriphidium herba-alba family Asteraceae has been used in the folk medicine by many cultures for treatment of various ailments since ancient times. In the current research we were aimed to evaluate the cancer chemopreventive activity of two crude extracts of S. herba-alba, methylene chloride extract and methanol extract on two cell lines: Human breast cancer cells (MCF-7 and human hepatocellular carcinoma cells (Hep-G2. Assessment of cytotoxicity using methyl thiazole tetrazolium (MTT assay indicated that both extracts exhibit poor cytotoxicity with half maximal inhibitory concentration (IC50 >20 µg/mL. Assessment of glutathione-S-transferases (GSTs activity (spectrophotometrically showed statistically significant enhancement of enzyme activity after treatment with three different doses of methylene chloride extract and glutathione (GSH concentrations were decreased. Analysis of cell mode of death by Ethidium bromide/Acridine orange (EB/AO staining revealed that the dominant mode of death in MCF-7 cells was apoptosis. Assessment of vascular endothelial growth factor (VEGF and platelets derived growth factor (PDGFBB using ELISA showed that VEGF and PDGFBB levels were statistically significant decreased. In Conclusion: both extracts may be cancer chemopreventive agents since they had tumor anti-initiating, and anti-promoting activity.

Acyclic retinoid in chemoprevention of hepatocellular carcinoma: Targeting phosphorylated retinoid X receptor-α for prevention of liver carcinogenesis

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Masahito Shimizu

2012-01-01

Full Text Available One of the key features of hepatocellular carcinoma (HCC is the high rate of intrahepatic recurrence that correlates with poor prognosis. Therefore, in order to improve the clinical outcome for patients with HCC, development of a chemopreventive agent that can decrease or delay the incidence of recurrence is a critical issue for urgent investigation. Acyclic retinoid (ACR, a synthetic retinoid, successfully improves HCC patient survival by preventing recurrence and the formation of secondary tumors. A malfunction of the retinoid X receptor-α (RXRα due to phosphorylation by the Ras-MAPK signaling pathway plays a critical role in liver carcinogenesis, and ACR exerts chemopreventive effects on HCC development by inhibiting RXRα phosphorylation. Here, we review the relationship between retinoid signaling abnormalities and liver disease, the mechanisms of how RXRα phosphorylation contributes to liver carcinogenesis, and the detailed effects of ACR on preventing HCC development, especially based on the results of our basic and clinical research. We also outline the concept of "clonal deletion and inhibition" therapy, which is defined as the removal and inhibition of latent malignant clones from the liver before they expand into clinically detectable HCC, because ACR prevents the development of HCC by implementing this concept. Looking toward the future, we discuss "combination chemoprevention" using ACR as a key drug since it can generate a synergistic effect, and may thus be an effective new strategy for the prevention of HCC.

Synthesis and characterization of tris[butyl-(1-methyl-3-phenyl-propyl)-dithiocarbamato]-cobalt(III) seskvitoluene

OpenAIRE

TIBOR SABO; ISMET M. HODZIC; SRECKO R. TRIFUNOVIC; VESNA M. DJINOVIC; GORAN N. KALUDJEROVIC

2002-01-01

A new bidentate ligand butyl-(1-methyl-3-phenyl-propyl)-dithiocarbamate (bmFpdtc) was prepared, as the sodium salt. In the reaction of hexaaminecobalt(III) chloride with NabmFpdtc, the corresponding tris[butyl-(1-methyl-3-phenyl-propyl)-dithiocarbamato]cobalt(III), [Co(bmFpdtc)3] complex was prepared. The complex was characterized by elemental analysis, infrared, electronic absorption, 1H and 13C-NMR spectroscopy.

Aspirin as a chemoprevention agent for colorectal cancer.

LENUS (Irish Health Repository)

Lee, Chun Seng

2012-11-01

Colorectal cancer (CRC) is one of the leading causes of mortality in the western world. It is widely accepted that neoplasms such as colonic polyps are precursors to CRC formation; with the polyp-adenoma-carcinoma sequences well described in medical literature [1, 2]. It has been shown that Aspirin and other non-steroid anti-inflammatory drugs (NSAID) have a negative effect on polyp and cancer formation. This review aims to describe some of the mechanism behind the chemoprotective properties of aspirin; COX 2 inhibition, regulation of proliferation and apoptosis and effects on the immune system and also the current evidence that supports its use as a chemoprevention agent against CRC. We will also aim to explore the side effects with the use of aspirin and the pitfalls of using aspirin routinely for primary prophylaxis against CRC.

ent-Rosane and abietane diterpenoids as cancer chemopreventive agents.

Science.gov (United States)

Núñez, Marvin J; Reyes, Carolina P; Jiménez, Ignacio A; Hayashi, Hirotaka; Tokuda, Harukuni; Bazzocchi, Isabel L

2011-04-01

Two ent-rosane- (cuzcol, 1 and 6-dehydroxycuzcol, 2) and a abietatriene- (salvadoriol, 3) type diterpenoids have been isolated from Maytenus cuzcoina and Crossopetalum uragoga, respectively, along with five known diterpene compounds (4-8). Their stereostructures have been elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques, and computational data. The absolute configuration of cuzcol was determined by application of Riguera ester procedure. This is the first instance of isolation of ent-rosane diterpenoids from species of the Celastraceae. The isolated diterpenes were found to be potent anti-tumour-promoter agents, and carnosol (7) also showed a remarkable chemopreventive effect in an in vivo two-stage carcinogenesis model. Copyright © 2011 Elsevier Ltd. All rights reserved.

Sorption of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) to synthetic resins.

Science.gov (United States)

Bi, Erping; Haderlein, Stefan B; Schmidt, Torsten C

2005-10-01

Methyl tert-butyl ether (MTBE) is a widely used gasoline oxygenate. Contamination of MTBE and its major degradation product tert-butyl alcohol (TBA) in groundwater and surface water has received great attention. However, sorption affinity and sorption mechanisms of MTBE and TBA to synthetic resins, which can be potentially used in removal of these contaminants from water, in passive sampling, or in enrichment of bacteria, have not been studied systemically. In this study, kinetic and equilibrium sorption experiments (single solute and binary mixtures) on four synthetic resins were conducted. The sorption affinity of the investigated sorbents for MTBE and TBA decreases in the order Ambersorb 563>Optipore L493>Amberlite XAD4>Amberlite XAD7, and all show higher sorption affinity for MTBE than for TBA. Binary experiments with o-xylene, a major compound of gasoline as co-contaminant, imply that all resins preferentially sorb o-xylene over MTBE or TBA, i.e., there is sorption competition. In the equilibrium aqueous concentration (Ceq) range (0.1-139.0 mg/L for MTBE, and 0.01-48.4 mg/L for TBA), experimental and modeling results as well as sorbent characteristics indicate that micropore filling and/or some other type of adsorption process (e.g., adsorption to specific sites of high sorption potential at low concentrations) rather than partitioning were the dominant sorption mechanisms. Optipore L493 has favourable sorption and desorption characteristics, and is a suitable sorbent, e.g., in bacteria enrichment or passive sampling for moderately polar compounds. However, for highly polar compounds such as TBA, Ambersorb 563 might be a better choice, especially in water treatment.

Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

Energy Technology Data Exchange (ETDEWEB)

Francois, A

2002-11-01

Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

Synthesis and characterization of tris[butyl-(1-methyl-3-phenyl-propyl-dithiocarbamato]-cobalt(III seskvitoluene

Directory of Open Access Journals (Sweden)

TIBOR SABO

2002-02-01

Full Text Available A new bidentate ligand butyl-(1-methyl-3-phenyl-propyl-dithiocarbamate (bmFpdtc was prepared, as the sodium salt. In the reaction of hexaaminecobalt(III chloride with NabmFpdtc, the corresponding tris[butyl-(1-methyl-3-phenyl-propyl-dithiocarbamato]cobalt(III, [Co(bmFpdtc3] complex was prepared. The complex was characterized by elemental analysis, infrared, electronic absorption, 1H and 13C-NMR spectroscopy.

Polyvinylpolypyrrolidone-Supported Boron Trifluoride; Highly Efficient Catalyst for the Synthesis of N-tert-Butyl Amides

Directory of Open Access Journals (Sweden)

Masoud Mokhtary

2012-01-01

Full Text Available Highly efficient method for the preparation of N-tert-butyl amides by reaction of nitriles with tert-butyl acetate is described using polyvinylpolypyrrolidone-supported boron trifluoride (PVPP-BF3 at 70°C in good to excellent yields. Selective amidation of benzonitrile in the presence of acetonitrile was also achieved. polyvinylpolypyrrolidone-boron trifluoride complex shows non-corrosive and stable solid catalyst elevated Lewis acid property.

Chemistry and in vitro antioxidant activity of volatile oil and oleoresins of black pepper (Piper nigrum).

Science.gov (United States)

Kapoor, I P S; Singh, Bandana; Singh, Gurdip; De Heluani, Carola S; De Lampasona, M P; Catalan, Cesar A N

2009-06-24

Essential oil and oleoresins (ethanol and ethyl acetate) of Piper nigrum were extracted by using Clevenger and Soxhlet apparatus, respectively. GC-MS analysis of pepper essential oil showed the presence of 54 components representing about 96.6% of the total weight. beta-Caryophylline (29.9%) was found as the major component along with limonene (13.2%), beta-pinene (7.9%), sabinene (5.9%), and several other minor components. The major component of both ethanol and ethyl acetate oleoresins was found to contain piperine (63.9 and 39.0%), with many other components in lesser amounts. The antioxidant activities of essential oil and oleoresins were evaluated against mustard oil by peroxide, p-anisidine, and thiobarbituric acid. Both the oil and oleoresins showed strong antioxidant activity in comparison with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) but lower than that of propyl gallate (PG). In addition, their inhibitory action by FTC method, scavenging capacity by DPPH (2,2'-diphenyl-1-picrylhydrazyl radical), and reducing power were also determined, proving the strong antioxidant capacity of both the essential oil and oleoresins of pepper.

Alterations in the metabolism of benzo[a]pyrene in syrian hamster embryo (SHE) cells pretreated with phenolic antioxidants

International Nuclear Information System (INIS)

Strniste, G.F.; Okinaka, R.T.; Chen, D.J.

1983-01-01

Inhibition of chemical- or radiation-induced neoplasia has been observed in animals whose diets were supplemented with antioxidants commonly used as food additives. Inhibition of the carcinogenicity of benzo[a]pyrene (BaP) or of 7,12-dimenthylbenz[a]anthracene (DMBA) - in rats has been achieved by the addition of the phenolic antioxidants butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT) to the diet. Our data suggest that in SHE cells antioxidants inhibit the overall metabolism of BaP to its various oxidized moieties including 7,8-diol- and 7,8,9,10-tetrol-BaP. A plausible explanation for our results with SHE cells is that the antioxidants interact directly with AHH, thus inhibiting AHH metabolic capacity. From analysis of nuclear material from SHE cells (+- antioxidants) incubated for 36 hours with BaP at 1 μg/ml, it is calculated that 4.6, 2.4 and 2.9 pmol BaP are bound to the DNA isolated from 10 7 nuclei of control, BHA-(20 μg/ml) and p-MP-(10 μg/ml) treated cultures, respectively

Research into the functional components and antioxidant activities of North China rice wine (Ji Mo Lao Jiu)

Science.gov (United States)

He, Shuai; Mao, Xiangzhao; Liu, Pei; Lin, Hong; Du, Zuyuan; Lv, Ning; Han, Jichen; Qiu, Cuifang

2013-01-01

Over the last decade, considerable experimental evidence has supported the view that grape wine and South China rice wine are rich in diverse nutrients and have powerful antioxidant activity. However, little research has been carried out for North China rice wine, of which Ji Mo Lao Jiu (JMLJ) is the outstanding representative. In this study, the functional components and antioxidant activity of JMLJ were investigated. Twenty-eight free amino acids were found in JMLJ, much more than that previously reported in other Chinese rice wines (16–21). Functional oligosaccharides (5290.222 mg/L), total phenols (722.431 ± 10.970 mg/L), and mineral elements (9) were rich in JMLJ. When compared with synthetic antioxidants, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), JMLJ showed effective 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging and reducing capacity. The results of this study lay the foundation for promoting the utilization of JMLJ and the development of North China rice wine in the food industry. PMID:24804035

Tri(t-butyl)phosphine-assisted selective hydrosilylation of terminal alkynes

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

A highly efficient and regio-/stereoselective method of hydrosilylating terminal alkynes was developed using Pt(DVDS)-tri(t-butyl) phosphine catalyst system at room temperature.Trans-products or alpha-products were obtained almost exclusively depending on the alkynes and silanes employed.

Atom transfer radical copolymerization of styrene and butyl acrylate

NARCIS (Netherlands)

Chambard, G.; Klumperman, B.; Matyjaszewski, K.

2000-01-01

Atom transfer radical polymerization of styrene and butyl acrylate has been investigated from a kinetic point of view. Attention is focused on the activation of the dormant species as well as on the termination that plays a role in these reactions. It has been shown that the activation of a styrene

Thermodynamic properties of 1-butyl-3-methylpyridinium tetrafluoroborate

International Nuclear Information System (INIS)

Safarov, Javid; Kul, Ismail; El-Awady, Waleed A.; Shahverdiyev, Astan; Hassel, Egon

2011-01-01

Highlights: → (p, ρ, T) data of 1-butyl-3-methylpyridinium tetrafluoroborate are estimated. → The measurements were carried out with a vibration-tube densimeter. → The thermomechanical coefficients were calculated. - Abstract: Pressure, density, temperature (p, ρ, T) data of 1-butyl-3-methylpyridinium tetrafluoroborate [C4mpyr][BF 4 ] at T = (283.15 to 393.15) K and pressures up to p = 100 MPa are reported with an estimated experimental relative combined standard uncertainty of Δρ/ρ = ±(0.01 to 0.08)% in density. The measurements were carried out with a newly constructed Anton-Paar DMA HPM vibration-tube densimeter. The system was calibrated using double-distilled water, methanol, toluene and aqueous NaCl solutions. An empirical equation of state for fitting of the (p, ρ, T) data of [C4mpyr][BF 4 ] has been developed as a function of pressure and temperature to calculate the thermal properties of the ionic liquid (IL), such as isothermal compressibility, isobaric thermal expansibility, differences in isobaric and isochoric heat capacities, thermal pressure coefficient and internal pressure. Internal pressure and the temperature coefficient of internal pressure data were used to make conclusions on the molecular characteristics of the IL.

Influence Of Initiator Types And Emulsion Polymerization Techniques To Particle Size Of Copolymerization Styrene-Butyl Acrylate-Methyl Methacrylate

Directory of Open Access Journals (Sweden)

Ariyanti Sarwono

2008-11-01

Full Text Available Influence of initiator types and emulsion polymerization techniques to particle size of copolymerization styrene-butyl acrylate-methyl methacrylate. Copoly(styrene/butyl acrylic/methyl methacrylic was prepared by emulsion polymerization method. This paper describes effect of insiator types i.e. ammonium persulfate (APS, hydrogen peroxide, ters-butyl peroxide (TBHP, initiator redox (H2O2/ascorbic acid and polymerization techniques i.e. batch and semicontinue to particle size distribution of copoly(styrene/butyl acrylic/methyl methacrylic. Initiator TBHP and H2O2 could not initiate copolymerization properly, but initiator APS and redox initiate copolymerization with batch and semi continue techniques could well perform. The higher concentration of APS, the greater particle size of the copolymer, but the copolymer is polymodal. Initiator redox (H2O2/ascorbic acid produced greater particle size than initiator redox (ascorbic acid/ H2O2.

The chemopreventive action of bromelain, from pineapple stem (Ananas comosus L.), on colon carcinogenesis is related to antiproliferative and proapoptotic effects.

Science.gov (United States)

Romano, Barbara; Fasolino, Ines; Pagano, Ester; Capasso, Raffaele; Pace, Simona; De Rosa, Giuseppe; Milic, Natasa; Orlando, Pierangelo; Izzo, Angelo A; Borrelli, Francesca

2014-03-01

Colorectal cancer is an important health problem across the world. Here, we investigated the possible antiproliferative/proapoptotic effects of bromelain (from the pineapple stem Ananas comosus L., family Bromeliaceae) in a human colorectal carcinoma cell line and its potential chemopreventive effect in a murine model of colon cancer. Proliferation and apoptosis were evaluated in human colon adenocarcinoma (Caco-2) cells by the (3) H-thymidine incorporation assay and caspase 3/7 activity measurement, respectively. Extracellular signal-related kinase (ERK) and Akt expression were evaluated by Western blot analysis, reactive oxygen species production by a fluorimetric method. In vivo, bromelain was evaluated using the azoxymethane murine model of colon carcinogenesis. Bromelain reduced cell proliferation and promoted apoptosis in Caco-2 cells. The effect of bromelain was associated to downregulation of pERK1/2/total, ERK, and pAkt/Akt expression as well as to reduction of reactive oxygen species production. In vivo, bromelain reduced the development of aberrant crypt foci, polyps, and tumors induced by azoxymethane. Bromelain exerts antiproliferative and proapoptotic effects in colorectal carcinoma cells and chemopreventive actions in colon carcinogenesis in vivo. Bromelain-containing foods and/or bromelain itself may represent good candidates for colorectal cancer chemoprevention. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Health Promoting Effects of Brassica-Derived Phytochemicals: From Chemopreventive and Anti-Inflammatory Activities to Epigenetic Regulation

Directory of Open Access Journals (Sweden)

Anika Eva Wagner

2013-01-01

Full Text Available A high intake of brassica vegetables may be associated with a decreased chronic disease risk. Health promoting effects of Brassicaceae have been partly attributed to glucosinolates and in particular to their hydrolyzation products including isothiocyanates. In vitro and in vivo studies suggest a chemopreventive activity of isothiocyanates through the redox-sensitive transcription factor Nrf2. Furthermore, studies in cultured cells, in laboratory rodents, and also in humans support an anti-inflammatory effect of brassica-derived phytochemicals. However, the underlying mechanisms of how these compounds mediate their health promoting effects are yet not fully understood. Recent findings suggest that brassica-derived compounds are regulators of epigenetic mechanisms. It has been shown that isothiocyanates may inhibit histone deacetylase transferases and DNA-methyltransferases in cultured cells. Only a few papers have dealt with the effect of brassica-derived compounds on epigenetic mechanisms in laboratory animals, whereas data in humans are currently lacking. The present review aims to summarize the current knowledge regarding the biological activities of brassica-derived phytochemicals regarding chemopreventive, anti-inflammatory, and epigenetic pathways.

Endotoxin and cancer chemo-prevention.

Science.gov (United States)

Mastrangelo, Giuseppe; Fadda, Emanuela; Cegolon, Luca

2013-10-01

Reduced rates of lung cancer have been observed in several occupational groups exposed to high levels of organic dusts contaminated by endotoxin. The underlying anti-neoplastic mechanism of endotoxin may be an increased secretion of endogenous anti-neoplastic mediators and activation of the toll-like receptors (TLR). A detoxified endotoxin derivative, Monophosphoryl Lipid A (MPL(®)) is marketed in Europe since 1999 as part of the adjuvant systems in allergy vaccines for treatment of allergic rhino-conjunctivitis and allergic asthma. Over 200,000 patients have used them to date (nearly 70% in Germany). Since detailed exposure (MPL(®) dose and timing of administration) and individual data are potentially available, an observational follow-up study could be conducted in Germany to investigate the protective effect of MPL(®) against cancer, comparing cancer incidence in two groups of patients with allergic rhinitis: those treated with allergoids plus MPL(®) and those treated with a vaccine including the same allergoids but not MPL(®). The protective effect of MPL(®) could be quantified in ever and never smokers. If this proposed observational study provides evidence of protective effects, MPL(®) could be immediately used as a chemo-preventive agent since it is already in use as adjuvant in human vaccines against cancer. Copyright © 2013 Elsevier Ltd. All rights reserved.

Chemopreventive effects of in vitro digested and fermented bread in human colon cells.

Science.gov (United States)

Schlörmann, Wiebke; Hiller, Beate; Jahns, Franziska; Zöger, Romy; Hennemeier, Isabell; Wilhelm, Anne; Lindhauer, Meinolf G; Glei, Michael

2012-10-01

Bread as a staple food product represents an important source for dietary fibre consumption. Effects of wheat bread, wholemeal wheat bread and wholemeal rye bread on mechanisms which could have impact on chemoprevention were analysed in colon cells after in vitro fermentation. Effects of fermented bread samples on gene expression, glutathione S-transferase activity and glutathione content, differentiation, growth and apoptosis were investigated using the human colon adenoma cell line LT97. Additionally, apoptosis was studied in normal and tumour colon tissue by determination of caspase activities. The expression of 76 genes (biotransformation, differentiation, apoptosis) was significantly upregulated (1.5-fold) in LT97 cells. The fermented bread samples were able to significantly increase glutathione S-transferase activity (1.8-fold) and glutathione content (1.4-fold) of the cells. Alkaline phosphatase activity as a marker of differentiation was also significantly enhanced (1.7-fold). The fermented bread samples significantly inhibited LT97 cell growth and increased the level of apoptotic cells (1.8-fold). Only marginal effects on apoptosis in tumour compared to normal tissue were observed. This is the first study which presents chemopreventive effects of different breads after in vitro fermentation. In spite of differences in composition, the results were comparable between the bread types. Nevertheless, they indicate a potential involvement of this staple food product regarding the prevention of colon cancer.

Enhanced Heterogeneous Catalytic Conversion of Furfuryl Alcohol into Butyl Levulinate

NARCIS (Netherlands)

Carà, P.D..; Ciriminna, R.; Shiju, N.R.; Rothenberg, G.; Pagliaro, M.

2014-01-01

We study the catalytic condensation of furfuryl alcohol with 1-butanol to butyl levulinate. A screening of several commercial and as-synthesized solid acid catalysts shows that propylsulfonic acid-functionalized mesoporous silica outperforms the state-of-the-art phosphotungstate acid catalysts. The

Pressure-induced phase transition of 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6

Science.gov (United States)

Takekiyo, Takahiro; Hatano, Naohiro; Imai, Yusuke; Abe, Hiroshi; Yoshimura, Yukihiro

2011-03-01

We have investigated the pressure-induced Raman spectral change of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) using Raman spectroscopy. The relative Raman intensity at 590 cm-1 of the CH2 rocking band assigned to the gauche conformer of the NCCC dihedral angle of the butyl group in the [bmim]+ cation increases when the pressure-induced liquid-crystalline phase transition occurs, while that at 610 cm-1 assigned to the trans conformer decreases. Our results show that the high-pressure phase transition of [bmim][PF6] causes the increase of the gauche conformer of the [bmim]+ cation.

Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

Energy Technology Data Exchange (ETDEWEB)

Francois, A.

2002-11-01

Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

Gas chromatographic determination of Di-n-butyl phosphate in radioactive lean organic solvent of FBTR carbide fuel reprocessing

International Nuclear Information System (INIS)

Velavendan, P.; Ganesh, S.; Pandey, N.K.; Kamachi Mudali, U.; Natarajan, R.

2011-01-01

In the present work Di-n- butyl phosphate (DBP) a degraded product of Tri-n-butyl phosphate (TBP) formed by acid hydrolysis and radiolysis in the PUREX process was analyzed. Lean organic streams of different fuel burn-up FBTR carbide fuel reprocessing solution was determined by standard Gas Chromatographic technique. The method involves the conversion of non-volatile Di-n-butyl phosphate into volatile and stable derivatives by the action of diazomethane and then determined by Gas Chromatograph (GC). A calibration graph was made for DBP concentration range of 200-2000 ppm with correlation coefficient of 0.99587 and RSD 1.2 %. (author)

Chemopreventive Activities of Sulforaphane and Its Metabolites in Human Hepatoma HepG2 Cells

Directory of Open Access Journals (Sweden)

Peng Liu

2018-05-01

Full Text Available Sulforaphane (SFN exhibits chemopreventive effects through various mechanisms. However, few studies have focused on the bioactivities of its metabolites. Here, three metabolites derived from SFN were studied, known as sulforaphane glutathione, sulforaphane cysteine and sulforaphane-N-acetylcysteine. Their effects on cell viability, DNA damage, tumorigenicity, cell migration and adhesion were measured in human hepatoma HepG2 cells, and their anti-angiogenetic effects were determined in a 3D co-culture model of human umbilical vein endothelial cells (HUVECs and pericytes. Results indicated that these metabolites at high doses decreased cancer cell viability, induced DNA damage and inhibited motility, and impaired endothelial cell migration and tube formation. Additionally, pre-treatment with low doses of SFN metabolites protected against H2O2 challenge. The activation of the nuclear factor E2-related factor 2 (Nrf2-antioxidant response element (ARE pathway and the induction of intracellular glutathione (GSH played an important role in the cytoprotective effects of SFN metabolites. In conclusion, SFN metabolites exhibited similar cytotoxic and cytoprotective effects to SFN, which proves the necessity to study the mechanisms of action of not only SFN but also of its metabolites. Based on the different tissue distribution profiles of these metabolites, the most relevant chemical forms can be selected for targeted chemoprevention.

Intrinsic mitochondrial membrane potential change and associated events mediate apoptosis in chemopreventive effect of diclofenac in colon cancer.

Science.gov (United States)

Kaur, Jasmeet; Sanyal, S N

2010-01-01

The present study explored the role of intrinsic mitochondrial membrane potential (delta psi M) in NSAID-induced apoptosis in the early stages of colon cancer. 1,2-Dimethylhydrazine dihydrochloride (DMH) was used to induce colon cancer and its chemoprevention was studied by diclofenac in a rat model. After 6 weeks of treatment with DMH (early stage), morphological analysis revealed a marked occurrence of preneoplastic features [i.e., mucosal plaque lesions (MPLs) in the colonic tissue]. Coadministration of diclofenac with DMH resulted in a significant reduction of these lesions, thereby proving the chemopreventive efficacy of diclofenac at the chosen anti-inflammatory dose. DMH treatment also led to a significant increase in delta psi M in the isolated colonocytes as assessed by JC-1 fluorescent staining, measured both by fluorescence microscopy and spectrofluorometerically. Further, there was seen a reduction in the number of cells showing low delta psi M, and hence monomer intensity of JC-1 by DMH treatment. To study the mechanism of these alterations in delta psi M in the present work, we studied the protein expression of important proapoptotic proteins, cytochrome c and Bax, by Western blot analysis and immunohistochemistry. DMH treatment reduced the mitochondrial translocation of Bax whereas cytochrome c was found to be located prominently in the mitochondria. Protein expression of antiapoptotic Bcl-2 was also studied in the colonic mucosa, which was expectedly found to be overexpressed after DMH treatment. Diclofenac treatment ameliorated the elevated delta psi M and its associated events to exert its chemopreventive action against early stages of colon cancer.

Preparation of poly(acrylonitrile-butyl acrylate) gel electrolyte for lithium-ion batteries

International Nuclear Information System (INIS)

Tian Zheng; He Xiangming; Pu Weihua; Wan Chunrong; Jiang Changyin

2006-01-01

Poly(acrylonitrile-butyl acrylate) gel polymer electrolyte was prepared for lithium ion batteries. The preparation started with synthesis of poly(acrylonitrile-butyl acrylate) by radical emulsion polymerization, followed by phase inversion to produce microporous membrane. Then, the microporous gel polymer electrolytes (MGPEs) was prepared with the microporous membrane and LiPF 6 in ethylene carbonate/diethyl carbonate. The dry microporous membrane showed a fracture strength as high as 18.98 MPa. As-prepared gel polymer electrolytes presented ionic conductivity in excess of 3.0 x 10 -3 S cm -1 at ambient temperature and a decomposition voltage over 6.6 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for Li-ion batteries

Effect of Mesoporous Diatomite Particles on the Kinetics of SR&NI ATRP of Styrene and Butyl Acrylate

Science.gov (United States)

Khezri, Khezrollah; Ghasemi, Moosa; Fazli, Yousef

2018-05-01

Mesoporous diatomite particles were employed to prepare different poly(styrene-co-butyl acrylate)/diatomite nanocomposites. Diatomite nanoplatelets were used for in situ copolymerization of styrene and butyl acrylate by SR&NI ATRP to synthesize well-defined poly(styrene-co-butyl acrylate) nanocomposites. Nitrogen adsorption/desorption isotherm is applied to examine surface area and structural characteristics of the diatomite nanoplatelets. Evaluation of pore size distribution and morphological studies were also performed by SEM and TEM. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography respectively. Addition of 3 wt% pristine mesoporous diatomite nanoplatelets leads to increase of conversion from 73 to 89%. Molecular weight of poly(styrene-co-butyl acrylate) chains increases from 17,115 to 20,343 g·mol-1 by addition of 3 wt% pristine mesoporous diatomite; however, polydispersity index values increases from 1.14 to 1.37. Increasing thermal stability of the nanocomposites is demonstrated by TGA. Differential scanning calorimetry shows an increase in glass transition temperature from 35.26 to 39.61°C by adding 3 wt% of mesoporous diatomite nanoplatelets.

Continuous synthesis of tert.-butyl peroxypivalate using a single channel micro reactor equipped with orifices as emulsification units

NARCIS (Netherlands)

Illg, T.; Hessel, V.; Löb, P.; Schouten, J.C.

2011-01-01

The two-step synthesis of tert-butyl peroxypivalate is performed in a single-channel microreactor. The first step, the deprotonation of tert-butyl hydroperoxide, is done in a simple mixer tube setup. The residence time section for the second reaction step is equipped with orifices for interfacial

Butyl 2-(5-iodo-3-methylsulfinyl-1-benzofuran-2-ylacetate

Directory of Open Access Journals (Sweden)

Uk Lee

2009-02-01

Full Text Available In the title compound, C15H17IO4S, the O atom and the methyl group of the methylsulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. The crystal structure is stabilized by weak intermolecular C—H...π interactions between a methyl H atom of the methylsulfinyl group and the benzene ring of the benzofuran system, and by an I...O halogen bond of 3.173 (3 Å and a nearly linear C—I...O angle of 171.7 (1°. In addition, the crystal structure exhibits weak intermolecular C—H...O hydrogen bonds. The O atom of the carbonyl group and the butyl chain are both disordered over two positions with site-occupancy factors from refinement of 0.55 (4 and 0.45 (4 (for the O atom, and 0.76 (2 and 0.24 (2 (for the butyl group.

Crystal structure of 1-butyl-2,3-dimethylimidazolium dicarba-7,8-nido-undecaborate

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M. J. Klemes

2015-03-01

Full Text Available In the title molecular salt, C9H17N2+·C2H12B9−, the carborane cage has a bridging B—H—B bond on the open B3C2 face. The butyl side chain of the cation adopts an extended conformation [C—C—C—C = 179.6 (1°]. In the crystal, the imidazolium ring is almost coplanar with the open face of the carborane anion. The cations stack in the [010] direction and the dihedral angle between the imidazolium rings of adjacent cations is 68.45 (6°. The butyl chains extend into the space between carborane anions.

Percutaneous N-Butyl cyanoacrylate embolization of a pancreatic pseudoaneurysm after failed attempts of transcatheter embolization

Energy Technology Data Exchange (ETDEWEB)

Kim, Ri Hyeon; Yoo, Roh Eul; Kim, Hyo Cheol [Seoul National University Medical Research Center, and Clinical Research Institute, Seoul National University Hospital, Seoul (Korea, Republic of)

2014-10-15

One common complication after major pancreatic surgery is bleeding. Herein we describe a case of pancreatic pseudoaneurysm which developed after pylorous preserving pancreaticoduodenectomy for common bile duct cancer. Three attempts of transcatheter embolization failed since feeders to the pseudoaneurysm had unfavorable anatomy. Direct percutaneous N-butyl cyanoacrylate injection was performed under fluoroscopy-guidance and the pseudoaneurysm was successfully treated. Percutaneous fluoroscopy-guided direct N-butyl cyanoacrylate injection may be a useful alternative when selective transcatheter embolization fails or is technically challenging.

Chemopreventive Effect of Aster glehni on Inflammation-Induced Colorectal Carcinogenesis in Mice

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Kyung-Sook Chung

2018-02-01

Full Text Available Although Aster glehni is a common dietary herb that has various bioactivities, including anti-diabetic, anti-adipogenic, and anti-inflammatory effects, A. glehni has not been studied in colon cancer. Therefore, we hypothesized the chemopreventive effects of an ethanol extract of A. glehni (AG on azoxymethane/dextran sulfate sodium (AOM/DSS-induced colitis-associated cancer (CAC in mice. In this study, we found that treatment with AG significantly attenuated the AOM/DSS-induced enlargement of the spleen and shortening of the colon. In addition, colonic tumor formation, colonic damage, and increased muscle thickness were significantly reduced in AOM/DSS-induced mice fed AG. Treatment with AG also reduced intestinal interleukin (IL-1β, IL-6, and tumor necrosis factor (TNF-α production and decreased inducible nitric oxide synthase (iNOS and cyclooxygenase (COX-2 protein expression in mice with AOM/DSS-induced CAC. Furthermore, AG reduced nuclear factor (NF-κB activation via phosphorylation and degradation of inhibitor of kappa Bα (IκBα, leading to inhibition of NF-κB p65 nuclear translocation. It also downregulated the expression of NF-κB-related proteins, including the B-cell lymphoma 2 (Bcl-2 family and inhibitors of apoptosis proteins (IAPs, in mice with AOM/DSS-induced CAC. Taken together, these findings suggest that the treatment with AG inhibited colitis-associated colon carcinogenesis in mice, and this chemopreventive effect was strongly mediated by suppression of the NF-κB signaling pathway, indicating that AG could be a promising protective agent against CAC.

A comparison of the efficacy of various antioxidants on the oxidative stability of irradiated polyethylene.

Science.gov (United States)

Hope, Natalie; Bellare, Anuj

2015-03-01

Ultrahigh-molecular-weight polyethylene (UHMWPE) is subjected to radiation crosslinking to form highly crosslinked polyethylene (HXLPE), which has improved wear resistance. First-generation HXLPE was subjected to thermal treatment to reduce or quench free radicals that can induce long-term oxidative degeneration. Most recently, antioxidants have been added to HXLPE to induce oxidative resistance rather than by thermal treatment. However, antioxidants can interfere with the efficiency of radiation crosslinking. We sought to identify (1) which antioxidant from among those tested (vitamin E, β-carotene, butylated hydroxytoluene, or pentaerythritol tetrakis [methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]) causes the least reduction of crosslinking; (2) which promotes the greatest oxidative stability; and (3) which had the lowest ratio of oxidation index to crosslink density. Medical-grade polyethylene (PE) resin was blended with 0.1 weight % of the following stabilizers: alpha tocopherol (vitamin E), β-carotene, butylated hydroxytoluene (BHT), and pentaerythritol tetrakis [methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (a hindered phenol antioxidant [HPAO]). These blends were compression-molded into sheets and subjected to electron beam irradiation to a dose of 100 kGy. Equilibrium swelling experiments were conducted to calculate crosslink density. Each PE was subjected to accelerated aging for a period of 2 weeks and Fourier transform infrared spectroscopy was used to measure the maximum oxidation. Statistical analysis was conducted using analysis of variance with Fisher's protected least significant difference in which a p value of tested (1.49, ES = 1.94; 95% CI, 1.32-1.66) followed by HPAO-PE (1.70, ES = 1.52; 95% CI, 1.61-1.80), vitamin E-PE (2.21, ES = 0.52; 95% CI, 2.05-2.38), and β-carotene-PE (2.69, ES = -0.43; 95% CI, 2.46-2.93) compared with control PE (2.47, 95% CI, 2.07-2.88) with β-carotene (p = 0.208) and vitamin E (p = 0

Preparation of poly(acrylonitrile-butyl acrylate) gel electrolyte for lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Tian Zheng [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); He Xiangming [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)]. E-mail: hexm@tsinghua.edu.cn; Pu Weihua [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Wan Chunrong [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Jiang Changyin [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China)

2006-10-25

Poly(acrylonitrile-butyl acrylate) gel polymer electrolyte was prepared for lithium ion batteries. The preparation started with synthesis of poly(acrylonitrile-butyl acrylate) by radical emulsion polymerization, followed by phase inversion to produce microporous membrane. Then, the microporous gel polymer electrolytes (MGPEs) was prepared with the microporous membrane and LiPF{sub 6} in ethylene carbonate/diethyl carbonate. The dry microporous membrane showed a fracture strength as high as 18.98 MPa. As-prepared gel polymer electrolytes presented ionic conductivity in excess of 3.0 x 10{sup -3} S cm{sup -1} at ambient temperature and a decomposition voltage over 6.6 V. The results showed that the as-prepared gel polymer electrolytes were promising materials for Li-ion batteries.

Thermophysical properties of 1-butyl-4-methylpyridinium tetrafluoroborate

International Nuclear Information System (INIS)

Safarov, Javid; Kul, Ismail; El-Awady, Waleed A.; Nocke, Jürgen; Shahverdiyev, Astan; Hassel, Egon

2012-01-01

Highlights: ► (p, ρ, T) data of 1-butyl-4-methylpyridinium tetrafluoroborate are estimated. ► The measurements were carried out with a vibration-tube densimeter. ► The thermomechanical coefficients were calculated. - Abstract: Thermophysical properties, {(p, ρ, T) at T = (283.15 to 393.15) K, pressures up to p = 100 MPa, and viscosity at T = (283.15 to 373.15) K and p = 0.101 MPa}, of 1-butyl-4-methylpyridinium tetrafluoroborate [b4mpy][BF 4 ] are reported. The measurements were carried out with a recently constructed Anton-Paar DMA HPM vibration-tube densimeter and a fully automated SVM 3000 Anton-Paar rotational Stabinger viscometer. The vibration-tube densimeter was calibrated using double-distilled water, methanol, toluene, and aqueous NaCl solutions. An empirical equation of state for fitting of the (p, ρ, T) data of [b4mpy][BF 4 ] has been developed as a function of pressure and temperature to calculate the thermal properties of the ionic liquid (IL), such as isothermal compressibility, isobaric thermal expansibility, differences in isobaric and isochoric heat capacities, thermal pressure coefficient, and internal pressure. Internal pressure and the temperature coefficient of internal pressure data were used to make conclusions on the molecular characteristics of the IL.

Solvent and ion-pairing effects on the chlorine kinetic isotope effect of t-butyl chloride

International Nuclear Information System (INIS)

McCord, B.R.

1986-01-01

The solvolysis of t-butyl chloride and 1-adamantyl chloride was measured in mixtures of aqueous 2,2,2-trifluoroethanols and in mixtures of aqueous ethanols. The KIEs for t-butyl chloride at 25 0 C in 94% TFE/water, and 60% ethanol/water (solvent mixtures with similar polarity) were 1.0097 and 1.0104 respectively. Further investigations showed a KIE of 1.0104 in 50% ethanol/water and 1.0105 in 100% ethanol while the isotope effect in the fluorinated ethanols rose from 1.0094 in 99% TFE/water to 1.0101 in 70% ethanol/water. The KIE in all these solvents were shown to be directly proportional to the nucleophilicity of the solvent and indicates nucleophilic attack on an ion pair. The similar KIE of t-butyl chloride in the ethanol/water solvents was found to support the contention that solvent polarity exerts a minimal effect on the chlorine KIE

High-pressure phase behavior of propyl lactate and butyl lactate in supercritical carbon dioxide

International Nuclear Information System (INIS)

Cho, Dong Woo; Shin, Jungin; Shin, Moon Sam; Bae, Won; Kim, Hwayong

2012-01-01

Highlights: ► The phase behavior of propyl lactate and butyl lactate in scCO 2 was measured. ► Experimental data were correlated by the PR-EOS. ► The critical constants were estimated by the three group contribution methods. ► Acentric factor was estimated by the Lee–Kesler method. ► The Nannoolal–Rarey and Lee–Kesler method shows the best correlation results. - Abstract: Lactate esters synthesized with lactic acid and ester are used as solvents and reactants in various industries, including agricultural chemistry, pharmaceuticals, electronics, and fine chemicals. Among lactate esters, high purity propyl lactate and butyl lactate are used to produce fine chemicals and in the synthesis of chiral intermediates for use in pesticides and drugs. However, distillation for the removal of propyl lactate and butyl lactate alters or degenerates products due the high boiling points of these two lactate esters. This problem can be solved by supercritical fluid extraction (SCFE) at lower temperatures. SCFE process requires high-pressure phase behavior data on CO 2 and lactates for its design and operation. In this study, high-pressure phase behavior of propyl lactate and butyl lactate in CO 2 was measured from (323.2 to 363.2) K using a variable-volume view cell apparatus. Experimental data were well correlated by the Peng–Robinson equation of state using the van der Waals one-fluid mixing rules. The critical constants were estimated by the Joback method, the Constantinou–Gani method, and the Nannoolal–Rarey method. Acentric factor was estimated by the Lee–Kesler method.

The beneficial effects of mixing spiro-OMeTAD with n-butyl-substituted copper phthalocyanine for perovskite solar cells

International Nuclear Information System (INIS)

Nouri, Esmaiel; Wang, Yu-Long; Chen, Qian; Xu, Jia-Ju; Dracopoulos, Vassilios; Sygellou, Lamprini; Xu, Zong-Xiang; Mohammadi, Mohammad Reza; Lianos, Panagiotis

2016-01-01

Highlights: • Soluble n-butyl substituted copper phthalocyanine. • Mixture with spiro-OMeTAD and employment in perovskite solar cells. • Impressive improvement of perovskite solar cell efficiency. • n-Butyl derivative gives better results than tert-butyl derivative - Abstract: Perovskite solar cells have been constructed under ambient conditions by using 2,2',7,7'-Tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (spiro-OMeTAD) mixed with a small quantity of soluble tetra-n-butyl substituted copper phthalocyanine as hole transporting material. The introduction of the phthalocyanine derivative resulted in an impressive increase of cell efficiency, which changed from 10.4% in the absence to 15.4% in the presence of phthalocyanine. This effect is related to the creation of deep traps in the hole transporting phase which block back-travelling electrons as well as to the improvement of the structural quality of the spiro-OMeTAD film in the presence of phthalocyanine. Both functionalities decrease shunt paths within the hole transporting phase resulting in increasing the fill factor and the open-circuit voltage of the cell.

Hydrophobic hydration and anomalous excess partial molar volume of tert-butyl alcohol-water mixture studied by quasielastic neutron scattering

International Nuclear Information System (INIS)

Nakada, Masaru; Maruyama, Kenji; Misawa, Masakatsu; Yamamuro, Osamu

2007-01-01

Quasielastic neutron scattering has been used to investigate the hydration of alcohol clusters in tert-butyl alcohol-water mixture. The measurements were made in a range of alcohol concentration, x TBA , from 0.0 to 0.17 in mole fraction at 25degC. Fraction, α, of water molecules hydrated to fractal-surface of alcohol clusters in tert-butyl alcohol-water mixture was obtained as a function of alcohol concentration. Average hydration number N WS of tert-butyl alcohol molecule was derived from the value of α as a function of alcohol concentration. The value of N WS for an isolated alcohol molecule in water was 19-21. The anomalous excess partial molar volume of tert-butyl alcohol-water mixture was interpreted successfully by applying the same model with the same values of volume parameter as used for 1-propanol-water mixture, δ 1 (=-0.36 cm 3 ·mol -1 ) and δ 2 (=0.60 cm 3 ·mol -1 ). (author)

Quercetin protects human hepatoma HepG2 against oxidative stress induced by tert-butyl hydroperoxide

International Nuclear Information System (INIS)

Alia, Mario; Ramos, Sonia; Mateos, Raquel; Granado-Serrano, Ana Belen; Bravo, Laura; Goya, Luis

2006-01-01

Flavonols such as quercetin, have been reported to exhibit a wide range of biological activities related to their antioxidant capacity. The objective of the present study was to investigate the protective effect of quercetin on cell viability and redox status of cultured HepG2 cells submitted to oxidative stress induced by tert-butyl hydroperoxide. Concentrations of reduced glutathione and malondialdehyde, generation of reactive oxygen species and activity and gene expression of antioxidant enzymes were used as markers of cellular oxidative status. Pretreatment of HepG2 with 10 μM quercetin completely prevented lactate dehydrogenase leakage from the cells. Pretreatment for 2 or 20 h with all doses of quercetin (0.1-10 μM) prevented the decrease of reduced glutathione and the increase of malondialdehyde evoked by tert-butyl hydroperoxide in HepG2 cells. Reactive oxygen species generation induced by tert-butyl hydroperoxide was significantly reduced when cells were pretreated for 2 or 20 h with 10 μM and for 20 h with 5 μM quercetin. Finally, some of the quercetin treatments prevented the significant increase of glutathione peroxidase, superoxide dismutase, glutathione reductase and catalase activities induced by tert-butyl hydroperoxide. Gene expression of antioxidant enzymes was also affected by the treatment with the polyphenol. The results of the biomarkers analyzed clearly show that treatment of HepG2 cells in culture with the natural dietary antioxidant quercetin strongly protects the cells against an oxidative insult

Isotope effects and the temperature dependences of the hyperfine coupling constants of muoniated sec-butyl radicals in condensed phases.

Science.gov (United States)

Fleming, Donald G; Bridges, Michael D; Arseneau, Donald J; Chen, Ya Kun; Wang, Yan Alexander

2011-04-07

Reported here is the first μSR study of the muon (A(μ)) and proton (A(p)) β-hyperfine coupling constants (Hfcc) of muoniated sec-butyl radicals, formed by muonium (Mu) addition to 1-butene and to cis- and trans-2-butene. The data are compared with in vacuo spin-unrestricted MP2 and hybrid DFT/B3YLP calculations reported in the previous paper (I), which played an important part in the interpretation of the data. The T-dependences of both the (reduced) muon, A(μ)′(T), and proton, A(p)(T), Hfcc are surprisingly well explained by a simple model, in which the calculated Hfcc from paper I at energy minima of 0 and near ±120° are thermally averaged, assuming an energy dependence given by a basic 2-fold torsional potential. Fitted torsional barriers to A(μ)′(T) from this model are similar (~3 kJ/mol) for all muoniated butyl radicals, suggesting that these are dominated by ZPE effects arising from the C−Mu bond, but for A(p)(T) exhibit wide variations depending on environment. For the cis- and trans-2-butyl radicals formed from 2-butene, A(μ)′(T) exhibits clear discontinuities at bulk butene melting points, evidence for molecular interactions enhancing these muon Hfcc in the environment of the solid state, similar to that found in earlier reports for muoniated tert-butyl. In contrast, for Mu−sec-butyl formed from 1-butene, there is no such discontinuity. The muon hfcc for the trans-2-butyl radical are seemingly very well predicted by B3LYP calculations in the solid phase, but for sec-butyl from 1-butene, showing the absence of further interactions, much better agreement is found with the MP2 calculations across the whole temperature range. Examples of large proton Hfcc near 0 K are also reported, due to eclipsed C−H bonds, in like manner to C−Mu, which then also exhibit clear discontinuities in A(p)(T) at bulk melting points. The data suggest that the good agreement found between theory and experiment from the B3LYP calculations for eclipsed bonds in

Solution of a gallstone with methyl-tertiary butyl ether

Energy Technology Data Exchange (ETDEWEB)

Brambs, H J; Roeren, T; Holstege, A; Raedecke, J

1987-08-01

Methyl-t-butyl ether is a new agent to dissolve gallstones. The substance proves to be very successful and acts very rapidly. A percutaneous transhepatic drainage supplies an adequate access route to dissolve calculi within the bile ducts. We report the case of a patient where before insertion of an internal stent a stone in the common bile duct was dissolved within 3 1/2 hours.

EFFICACY OF HYOSCINE BUTYL BROMIDE SUPPOSITORY FOR POSTOPERATIVE PAIN RELIEF

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Soniya C. Alphonse

2017-07-01

Full Text Available BACKGROUND Caesarean Section is on the rise all over the world. Women undergoing Caesarean section often wish to be awake post operatively and to avoid excessive medications affecting interactions with the new born infant. Multimodal pain therapy has been advocated for postoperative pain management after caesarean section. MATERIALS AND METHODS The study is a prospective randomized controlled study conducted at a tertiary care hospital to study the effect of Hyoscine Butyl Bromide Suppositories for postoperative analgesia following elective repeat caesarean section. The study included sixty patients divided into two groups- Group1 (study group were given Hyoscine Butyl Bromide Suppository (10 mg along with Injection. Tramadol 50 mg IM and Group II (control group were given Injection Tramadol IM only at the end of surgery. Pain score of the patient assessed at 1 hr, 2 hrs, 6hrs and 24 hrs post operatively. The total no of doses of injection tramadol needed in 24 hrs and the interval between 1st and 2nd dose of tramadol was also noted. The adverse effects of the drug and additional advantages of the drug if any were also assessed. RESULTS There was no statistically significant difference in pain score during the assessment intervals between the two groups. There was no difference in the number of doses of tramadol needed in the first 24 hrs. The mean interval between the 1st and 2nd dose of tramadol was found to be 7.6538 hours for group 1 patients and 6.9130 for group patients which was found to be statistically significant. There was no statistically significant side effects/ additional advantages for the drugs. CONCLUSION Concurrent administration of Hyoscine Butyl Bromide Suppository (10 mg and injection Tramadol 50 mg IM offers a longer postoperative analgesia without any increased adverse effects.

Occult progression by Apc-deficient intestinal crypts as a target for chemoprevention

Science.gov (United States)

Liskay, R.Michael

2014-01-01

Although Apc mutation is widely considered an initiating event in colorectal cancer, little is known about the earliest stages of tumorigenesis following sporadic Apc loss. Therefore, we have utilized a novel mouse model that facilitates the sporadic inactivation of Apc via frameshift reversion of Cre in single, isolated cells and subsequently tracks the fates of Apc-deficient intestinal cells. Our results suggest that consistent with Apc being a ‘gatekeeper’, loss of Apc early in life during intestinal growth leads to adenomas or increased crypt fission, manifested by fields of mutant but otherwise normal-appearing crypts. In contrast, Apc loss occurring later in life has minimal consequences, with mutant crypts being less prone to either increased crypt fission or adenoma formation. Using the stem cell-specific Lgr5-CreER mouse, we generated different sized fields of Apc-deficient crypts via independent recombination events and found that field size correlates with progression to adenoma. To evaluate this early stage prior to adenoma formation as a therapeutic target, we examined the chemopreventive effects of sulindac on Apc-deficient occult crypt fission. We found that sulindac treatment started early in life inhibits the morphologically occult spread of Apc-deficient crypts and thus reduces adenoma numbers. Taken together these results suggest that: (i) earlier Apc loss promotes increased crypt fission, (ii) a field of Apc-deficient crypts, which can form via occult crypt fission or independent neighboring events, is an important intermediate between loss of Apc and adenoma formation and (iii) normal-appearing Apc-deficient crypts are potential unappreciated targets for cancer screening and chemoprevention. PMID:23996931

Effect of Anion on Behaviour of Li-S Battery Electrolyte Solutions Based on N-Methyl-N-Butyl-Pyrrolidinium Ionic Liquids

International Nuclear Information System (INIS)

Barghamadi, Marzieh; Best, Adam S.; Bhatt, Anand I.; Hollenkamp, Anthony F.; Mahon, Peter J.; Musameh, Mustafa; Rüther, Thomas

2015-01-01

The electrochemical behaviour and electrical performance are investigated for a series of lithium-sulfur (Li-S) cells in which the electrolyte solutions are organic solvent-ionic liquid mixtures that are based on the 1-butyl-1-methylpyrrolidinium (C 4 mpyr) cation with a range of anions. In each case, performance is compared with cells that are based on a standard mixed-ether organic electrolyte. The capacity of cells assembled with electrolytes containing 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl) trifluorophosphate (C 4 mpyr-FAP), 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate (C 4 mpyr-OTf), or 1-butyl-1-methylpyrrolidinium tricyanomethanide (C 4 mpyr-TCM) decline rapidly due to low conductivity, high polysulfide solubility and side reaction of electrolyte with electrodes, respectively. Our results confirm that polysulfide solubility is strongly controlled by the anion of the ionic liquid and verify that not all ionic liquids decrease polysulfide solubility. In agreement with previous reports, 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (C 4 mpyr-TFSI) shows the best compatibility in Li-S batteries and has a higher coulombic efficiency of greater than 99% over 100 cycles. Furthermore, impedance spectroscopy confirms that electrolyte composition influences the SEI layer formed on the lithium anode and its subsequent impedance.

The chemopreventive activity of the histone deacetylase inhibitor tributyrin in colon carcinogenesis involves the induction of apoptosis and reduction of DNA damage

Energy Technology Data Exchange (ETDEWEB)

Heidor, Renato [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Furtado, Kelly Silva; Ortega, Juliana Festa [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Oliveira, Tiago Franco de [Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Tavares, Paulo Eduardo Latorre Martins; Vieira, Alessandra; Miranda, Mayara Lilian Paulino [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Purgatto, Eduardo [Laboratory of Food Chemistry and Biochemistry, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Moreno, Fernando Salvador, E-mail: rmoreno@usp.br [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil)

2014-04-15

The chemopreventive activity of the histone deacetylase inhibitor (HDACi) tributyrin (TB), a prodrug of butyric acid (BA), was evaluated in a rat model of colon carcinogenesis. The animals were treated with TB (TB group: 200 mg/100 g of body weight, b.w.) or maltodextrin (MD isocaloric control group: 300 mg/100 g b.w.) daily for 9 consecutive weeks. In the 3rd and 4th weeks of treatment, the rats in the TB and MD groups were given DMH (40 mg/kg b.w.) twice a week. After 9 weeks, the animals were euthanized, and the distal colon was examined. Compared with the control group (MD group), TB treatment reduced the total number of aberrant crypt foci (ACF; p < 0.05) as well as the ACF with ≥ 4 crypts (p < 0.05), which are considered more aggressive, but not inhibited the formation of DMH-induced O6-methyldeoxyguanosine DNA adducts. The TB group also showed a higher apoptotic index (p < 0.05) and reduced DNA damage (p < 0.05) compared with MD group. TB acted as a HDACi, as rats treated with the prodrug of BA had higher levels of histone H3K9 acetylation compared with the MD group (p < 0.05). TB administration resulted in increased colonic tissue concentrations of BA (p < 0.05) compared with the control animals. These results suggest that TB can be considered a promising chemopreventive agent for colon carcinogenesis because it reduced the number of ACF, including those that were more aggressive. Induction of apoptosis and reduction of DNA damage are cellular mechanisms that appear to be involved in the chemopreventive activity of TB. - Highlights: • Tributyrin is a chemopreventive agent for rat colon aberrant crypt foci. • Tributyrin increased apoptosis in an experimental rat colon carcinogenesis model. • Tributyrin treatment in a rat colon carcinogenesis model decreased DNA damage. • Tributyrin treatment induced H3K9 acetylation in a rat colon carcinogenesis model.

The chemopreventive activity of the histone deacetylase inhibitor tributyrin in colon carcinogenesis involves the induction of apoptosis and reduction of DNA damage

International Nuclear Information System (INIS)

Heidor, Renato; Furtado, Kelly Silva; Ortega, Juliana Festa; Oliveira, Tiago Franco de; Tavares, Paulo Eduardo Latorre Martins; Vieira, Alessandra; Miranda, Mayara Lilian Paulino; Purgatto, Eduardo; Moreno, Fernando Salvador

2014-01-01

The chemopreventive activity of the histone deacetylase inhibitor (HDACi) tributyrin (TB), a prodrug of butyric acid (BA), was evaluated in a rat model of colon carcinogenesis. The animals were treated with TB (TB group: 200 mg/100 g of body weight, b.w.) or maltodextrin (MD isocaloric control group: 300 mg/100 g b.w.) daily for 9 consecutive weeks. In the 3rd and 4th weeks of treatment, the rats in the TB and MD groups were given DMH (40 mg/kg b.w.) twice a week. After 9 weeks, the animals were euthanized, and the distal colon was examined. Compared with the control group (MD group), TB treatment reduced the total number of aberrant crypt foci (ACF; p < 0.05) as well as the ACF with ≥ 4 crypts (p < 0.05), which are considered more aggressive, but not inhibited the formation of DMH-induced O6-methyldeoxyguanosine DNA adducts. The TB group also showed a higher apoptotic index (p < 0.05) and reduced DNA damage (p < 0.05) compared with MD group. TB acted as a HDACi, as rats treated with the prodrug of BA had higher levels of histone H3K9 acetylation compared with the MD group (p < 0.05). TB administration resulted in increased colonic tissue concentrations of BA (p < 0.05) compared with the control animals. These results suggest that TB can be considered a promising chemopreventive agent for colon carcinogenesis because it reduced the number of ACF, including those that were more aggressive. Induction of apoptosis and reduction of DNA damage are cellular mechanisms that appear to be involved in the chemopreventive activity of TB. - Highlights: • Tributyrin is a chemopreventive agent for rat colon aberrant crypt foci. • Tributyrin increased apoptosis in an experimental rat colon carcinogenesis model. • Tributyrin treatment in a rat colon carcinogenesis model decreased DNA damage. • Tributyrin treatment induced H3K9 acetylation in a rat colon carcinogenesis model

In Vivo Immunomodulation and Lipid Peroxidation Activities Contributed to Chemoprevention Effects of Fermented Mung Bean against Breast Cancer

Directory of Open Access Journals (Sweden)

Swee Keong Yeap

2013-01-01

Full Text Available Mung bean has been reported to have antioxidant, cytotoxic, and immunomodulatory effects in vitro. Fermented products are reported to have enhanced immunomodulation and cancer chemopreventive effects. In this study, fermented mung bean treatments in vivo were studied by monitoring tumor development, spleen immunity, serum cytokine (interleukin 2 and interferon gamma levels, and spleen/tumor antioxidant levels after injection with low and high risk 4T1 breast cancer cells. Pretreatment with fermented mung bean was associated with delayed tumor formation in low risk mice. Furthermore, this treatment was connected with higher serum anticancer cytokine levels, spleen T cell populations, splenocyte cytotoxicity, and spleen/tumor antioxidant levels. Histopathological evaluation of fermented mung bean treated tumor revealed lower event of mitotic division. On the other hand, antioxidant and nitric oxide levels that were significantly increased in the untreated mice were inhibited in the fermented mung bean treated groups. These results suggested that fermented mung bean has potential cancer chemoprevention effects through the stimulation of immunity, lipid peroxidation, and anti-inflammation.

A Study of the Teratogenicity of Butylated Hydroxyanisole on Rabbits

DEFF Research Database (Denmark)

Hansen, Ernst; Meyer, Otto A.

1978-01-01

A teratogenicity study on butylated hydroxyanisole (BHA) was carried out in SPF New Zealand White rabbits. BHA was given by gavage from day 7–18 of the gestation period in doses of 0, 50, 200 and 400 mg/kg body wt./day. The fetuses were removed on day 28. No effect related to the treatment with BHA...

Recanalization of Splenic Artery Aneurysm After Transcatheter Arterial Embolization Using N-Butyl Cyanoacrylate

International Nuclear Information System (INIS)

Matsumoto, Keiji; Ushijima, Yasuhiro; Tajima, Tsuyoshi; Nishie, Akihiro; Hirakawa, Masakazu; Ishigami, Kousei; Yamaji, Yukiko; Honda, Hiroshi

2010-01-01

A 65-year-old woman who had been diagnosed as having microscopic polyangiitis developed sudden abdominal pain and entered a state of shock. Abdominal CT showed massive hemoperitoneum, and emergent angiography revealed a ruptured splenic artery aneurysm. After direct catheterization attempts failed due to tortuous vessels and angiospasm, transcatheter arterial embolization using an n-butyl cyanoacrylate (NBCA)-lipiodol mixture was successfully performed. Fifty days later, the patient developed sudden abdominal pain again. Repeated angiography demonstrated recanalization of the splenic artery and splenic artery aneurysm. This time, the recanalized aneurysm was embolized using metallic coils with the isolation method. Physicians should keep in mind that recanalization can occur after transcatheter arterial embolization using N-butyl cyanoacrylate, which has been used as a permanent embolic agent.

Inhibition of Akt enhances the chemopreventive effects of topical rapamycin in mouse skin

Science.gov (United States)

Dickinson, Sally E; Janda, Jaroslav; Criswell, Jane; Blohm-Mangone, Karen; Olson, Erik R.; Liu, Zhonglin; Barber, Christie; Rusche, Jadrian J.; Petricoin, Emmanuel; Calvert, Valerie; Einspahr, Janine G.; Dickinson, Jesse; Stratton, Steven P.; Curiel-Lewandrowski, Clara; Saboda, Kathylynn; Hu, Chengcheng; Bode, Ann M.; Dong, Zigang; Alberts, David S.; Bowden, G. Timothy

2016-01-01

The PI3Kinase/Akt/mTOR pathway has important roles in cancer development for multiple tumor types, including UV-induced non-melanoma skin cancer. Immunosuppressed populations are at increased risk of aggressive cutaneous squamous cell carcinoma (SCC). Individuals who are treated with rapamycin, (sirolimus, a classical mTOR inhibitor) have significantly decreased rates of developing new cutaneous SCCs compared to those that receive traditional immunosuppression. However, systemic rapamycin use can lead to significant adverse events. Here we explored the use of topical rapamycin as a chemopreventive agent in the context of solar simulated light (SSL)-induced skin carcinogenesis. In SKH-1 mice, topical rapamycin treatment decreased tumor yields when applied after completion of 15 weeks of SSL exposure compared to controls. However, applying rapamycin during SSL exposure for 15 weeks, and continuing for 10 weeks after UV treatment, increased tumor yields. We also examined whether a combinatorial approach might result in more significant tumor suppression by rapamycin. We validated that rapamycin causes increased Akt (S473) phosphorylation in the epidermis after SSL, and show for the first time that this dysregulation can be inhibited in vivo by a selective PDK1/Akt inhibitor, PHT-427. Combining rapamycin with PHT-427 on tumor prone skin additively caused a significant reduction of tumor multiplicity compared to vehicle controls. Our findings indicate that patients taking rapamycin should avoid sun exposure, and that combining topical mTOR inhibitors and Akt inhibitors may be a viable chemoprevention option for individuals at high risk for cutaneous SCC.

Ion chromatographic determination of Di-n-butyl phosphate in degraded organic solvent

International Nuclear Information System (INIS)

Velavendan, P.; Pandey, N.K.; Kamachi Mudali, U.; Natarajan, R.

2011-01-01

In the present work a method for the determination of Di-n-butyl phosphate in organic streams using Ion Chromatography technique is developed and described here. The method involves the separation of Di-n-butyl phosphate (DBP) from 30% TBP-NPH (Tri-n-butylphosphate diluted in Normal Paraffin Hydrocarbon) and uranium/nitric acid matrix by an extraction of DBP in alkaline medium and subsequent ion-exchange separation in ion chromatography column followed by suppressed conductivity detection. Direct determination of DBP in lean/loaded organic solvent will lead to in accurate determination of DBP due to organic interference. DBP is quantified to lower limit of 1 ppm with 3% RSD. The results obtained with ion chromatographic technique are compared with those obtained by standard gas chromatographic technique. The developed method is much faster and total analysis can be completed within two hours. (author)

Study of the butyl acetate synthesis - 1. Catalyst selection

Directory of Open Access Journals (Sweden)

Álvaro Orjuela Londoño

2004-01-01

Full Text Available In this work, a laboratory scale selection study over eight catalytic agents was made, in the acetic acid and butyl alcohol esterification reaction (seven lon exchange resins and a zeolytic solid. Considering some physicochemical characteristics as the activation pre-treating requirements, acidity, thermal stability, reaction performance, etc., it was found that macroporous ion exchange resins are the most efficient catalysts, especially Lewatit K-2431 resin.

Standard thermochemical characteristics of combustion and formation of 3,5-di-tert-butyl-o-benzoquinone and 3,6-di-tert-butyl-o-benzoquinone at T = 298.15 K

International Nuclear Information System (INIS)

Pashanova, Kira I.; Abakumov, Gleb A.; Markin, Alexey V.; Piskunov, Alexander V.; Smirnova, Natalia N.

2016-01-01

Highlights: • We report the results of thermochemical study for benzoquinone derivatives. • Optimal conditions for determination of combustion energy for benzoquinone were done. • The formation enthalpies for crystalline benzoquinone have been detected at T = 298.15 K. • The formation enthalpy of isomeric quinones were compared. - Abstract: Optimal conditions for investigations of thermodynamic properties have been determined experimentally by the method of combustion calorimetry for compounds of the o-benzoquinone series. In the present work, the energies of combustion in oxygen were measured at T = 298.15 K by static bomb combustion calorimetry for 3,5-di-tert-butyl-o-benzoquinone and 3,6-di-tert-butyl-o-benzoquinone. The experimental values have been used to calculate the standard (p° = 0.1 MPa) molar enthalpy of combustion Δ_cH"o_m and formation Δ_fH"o_m for the examined compounds in the crystalline phase.

Inducing PLA/starch compatibility through butyl-etherification of waxy and high amylose starch

CSIR Research Space (South Africa)

Wokadala, OC

2014-06-01

Full Text Available In this study, waxy and high amylose starches were modified through butyl-etherification to facilitatecompatibility with polylactide (PLA). Fourier transform infrared spectroscopy, proton nuclear magneticresonance spectroscopy and wettability tests...

PHYSIOLOGICALLY BASED PHARMACOKINETIC MODEL FOR HUMAN EXPOSURES TO METHYL TERTIARY-BUTYL ETHER

Science.gov (United States)

Humans can be exposed by inhalation, ingestion, or dermal absorption to methyl tertiary-butyl ether (MTBE), an oxygenated fuel additive, from contaminated water sources. The purpose of this research was to develop a physiologically based pharmacokinetic model describing in human...

IRIS Toxicological Review of Tert-Butyl Alcohol (Tert-Butanol) (External Review Draft)

Science.gov (United States)

The IRIS Toxicological Review of tert-Butyl Alcohol (tert-Butanol) was released for external peer review in June 2017. EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) will conduct a peer review of the scientific basis supporting ...

IRIS Toxicological Review of Tert-Butyl Alcohol (Tert-Butanol) (Public Comment Draft)

Science.gov (United States)

EPA is developing an Integrated Risk Information System (IRIS) assessment of tert-butyl Alcohol (tert-butanol) and has released the public comment draft assessment for public comment and external peer review. When final, the assessment will appear on the IRIS databa...

IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) (Public Comment Draft)

Science.gov (United States)

In September 2016, the U.S. Environmental Protection Agency's (USEPA) released the draft Integrated Risk Information System (IRIS) Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE). Consistent with the 2013 IRIS Enhancements, draft IRIS assessments are released prior to e...

Phenolic extracts of coconut oil cake: a potential alternative for synthetic antioxidants

Directory of Open Access Journals (Sweden)

Kapila Nalawatta SENEVIRATNE

2016-01-01

Full Text Available Abstract Limitations of natural antioxidants include relatively low antioxidant activity, narrow range of food systems where the antioxidants are effective and limited thermal stability compared to synthetic antioxidants. In the present study, the phenolic extract of coconut oil cake (COCE was tested for antioxidant activity-related food stabilization. Heat stabilities of COCE and synthetic antioxidants were determined by measuring the indubbction time of sunflower oil enriched with heat-treated antioxidants. In the β-carotene-linoleate emulsion used for testing antioxidant activity, COCE can retain 96 ± 2% of initial colour intensity while BHT can retain 89 ± 2% of initial colour intensity at 60 µg mL–1 concentration after two hours. TBARS contents (MDA equivalents / kg of meat in COCE-treated and control pork samples after 14 days was 2.80 ± 0.57 and 22.55 ± 2.30 respectively. Heat stability varies in the order butylated hydroxytoluene (BHT < (butylated hydroxyanisole (BHA < COCE < tertiary butylhydroxyquinone (TBHQ. The results of these experiments suggest that COCE is a versatile and thermally stable natural antioxidant mixture effective in stabilizing many food systems.

Occurrence and potential crop uptake of emerging contaminants and related compounds in an agricultural irrigation network

International Nuclear Information System (INIS)

Calderón-Preciado, Diana; Matamoros, Víctor; Bayona, Josep M.

2011-01-01

Emerging contaminants have received much attention in recent years due to their presence in surface waters, but little attention has been paid to their occurrence in agricultural irrigation waters. This study investigated the occurrence of these compounds in an agricultural irrigation network in northeastern Spain and, for the first time, using two plant uptake models, estimated the concentration of selected micropollutants in crops. The concentration of micropollutants in agricultural irrigation waters ranged from 10 to 5130 ng L −1 and exhibited some attenuation over the course of the irrigation network. Bromoform, chloroform, diclofenac, caffeine, ibuprofen, naproxen, methyl dihydrojasmonate, galaxolide, butylated hydroxytoluene, and butylated hydroxyanisole were the most abundant contaminants (> 200 ng L −1 , on average). The estimated concentration of micropollutants in crops ranged from −1 , with the neutral compounds being the most abundant. Moreover, the predicted data obtained by fate models generally agreed with experimental data. Finally, human exposure to micropollutants through fruit and vegetable consumption was estimated to be 9.8 μg per person and week (Σ 27 contaminants detected). Further studies are needed to determine the health implications that the presence of these compounds in fruit and vegetables may have for consumers.

Effect of antioxidants and silicates on peroxides in povidone.

Science.gov (United States)

Narang, Ajit S; Rao, Venkatramana M; Desai, Divyakant S

2012-01-01

Reactive peroxides in povidone often lead to degradation of oxidation-labile drugs. To reduce peroxide concentration in povidone, the roles of storage conditions, antioxidants, and silicates were investigated. Povidone alone and its physical mixtures with ascorbic acid, propyl gallate, sodium sulfite, butylated hydroxyanisole (BHA), or butylated hydroxytoluene (BHT) were stored at 25 °C and 40 °C, at 11%, 32%, and 50% relative humidity. In addition, povidone solution in methanol was equilibrated with silicates (silica gel and molecular sieves), followed by solvent evaporation to recover povidone powder. Peroxide concentrations in povidone were measured. The concentration of peroxides in povidone increased under very-low-humidity storage conditions. Among the antioxidants, ascorbic acid, propyl gallate, and sodium sulfite reduced the peroxide concentration in povidone, whereas BHA and BHT did not. Water solubility appeared to determine the effectiveness of antioxidants. Also, some silicates significantly reduced peroxide concentration in povidone without affecting its functionality as a tablet binder. Porosity of silicates was critical to their ability to reduce the peroxide concentration in povidone. A combination of these approaches can reduce the initial peroxide concentration in povidone and minimize peroxide growth under routine storage conditions. Copyright © 2011 Wiley-Liss, Inc.

Cancer chemoprevention and cancer preventive vaccines--a call to action: leaders of diverse stakeholder groups present strategies for overcoming multiple barriers to meet an urgent need.

Science.gov (United States)

Herberman, Ronald B; Pearce, Homer L; Lippman, Scott M; Pyenson, Bruce S; Alberts, David S

2006-12-15

The emerging field of cancer prevention through chemoprevention agents and cancer vaccines offers significant promise for reducing suffering and death from cancer. However, that promise may not be kept unless major barriers to progress are lowered or eliminated. Among the most significant barriers are the relatively small investment from government and industry in research and development of cancer preventive agents; a predominant emphasis of translational cancer research on therapeutic interventions for metastatic or advanced cancer; complexities of prevention trial design; a relatively uncharted Food and Drug Administration (FDA) approval process for preventive agents; insufficient public and patient understanding of the importance and potential for cancer preventive measures, with consequent unpredictable public and patient willingness to take preventive agents; an uncertain reimbursement from payors; and limitations in patent law, liability protection, and data package exclusivity that undermine the opportunity for recouping investment. Viewed individually or collectively, each of these barriers serves as a substantial deterrent to intellectual and financial investment by all sectors of the cancer community. In an effort to ultimately overcome these barriers, a Cancer Prevention Research Summit was assembled June 12-13, 2006 in Bethesda, Maryland, organized by C-Change with support from the AACR. The Summit brought together some 120 leaders from private, public, and not-for-profit entities, including cancer researchers and clinicians; federal health officials; regulatory agency representatives; pharmaceutical, biotech, and food industry leaders; patent attorneys; economists; public and private provider group executives; and advocates. Participants engaged in a detailed process to more carefully define the major barriers, identify potential solutions, and formulate initial priorities and recommendations for action. At the conclusion of this dialogue among

Poly (ethylene oxide)-block-poly (n-butyl acrylate)-blockpoly (acrylic acid) triblock terpolymers with highly asymmetric hydrophilic blocks: synthesis and aqueous solution properties

OpenAIRE

Petrov, P. (Petar); Yoncheva, K. (Krassimira); Mokreva, P. (Pavlina); Konstantinov, S. (Spiro); Irache, J.M. (Juan Manuel); Müller, A.H.E. (Axel H.E.)

2013-01-01

The synthesis and aggregation behaviour in aqueous media of novel amphiphilic poly(ethylene oxide)- block-poly(n-butyl acrylate)-block-poly(acrylic acid) (PEO–PnBA–PAA) triblock terpolymers were studied. Terpolymers composed of two highly asymmetric hydrophilic PEO (113 monomer units) and PAA (10–17 units) blocks, and a longer soft hydrophobic PnBA block (163 or 223 units) were synthesized by atom transfer radical polymerisation (ATRP) of n-butyl acrylate and tert-butyl acrylate ...

IRIS Toxicological Review of Ethylene Glycol Mono-Butyl ...

Science.gov (United States)

EPA released the draft report, Toxicological Review for Ethylene Glycol Mono-Butyl Ether , that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process. Comments received from other Federal agencies and White House Offices are provided below with external peer review panel comments. EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of EGBE that will appear on the Integrated Risk Information System (IRIS) database.

Critical behavior in the system cyclopentanone + water + secondary butyl alcohol

Science.gov (United States)

Krishna, U. Santhi; Unni, P. K. Madhavan

2018-05-01

We report detailed measurements of coexistence surface in the ternary system cylcopentanone + water + secondary butyl alcohol. The coexistence surface is seen to have an unusual tunnel like feature and is a potential system in which special critical points such as the Quadruple Critical Point (QCP) could be studied. Analysis of coexistence curves indicates that the system shows 3D-Ising like critical behavior.

Di-iso-Butyl Phthalate MATERNAL AND FETAL DATA FROM ...

Science.gov (United States)

this file contains the raw data on the effects of in utero administration of di-iso-butyl phthalate on maternal weight gain during dosing and the numbers of fetuses and fetal resorptions. The data have all been previously published, as described on the file metadata sheet. Raw data file from our published studies on DIBP specifically requested (6/14/2016) by NCEA scientists for analysis and inclusion in their assessment of this chemical.

IRIS Toxicological Review of Ethylene Glycol Mono Butyl Ether (Egbe) (Final Report)

Science.gov (United States)

EPA has finalized the Toxicological Review of Ethylene Glycol Mono Butyl Ether: in support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health.

A thermal lensing study of a photolysis of di- t-butyl peroxide

Science.gov (United States)

Fuke, K.; Hasegawa, A.; Ueda, M.; Itoh, M.

1981-11-01

A photolysis of di- t-butyl peroxide (BOOB) was studied by using a thermal lensing technique. This technique is found to be applicable to the determination Of the rate Constants of the decay of t-butoxy radical (BO ) and the hydrogen abstraction reaction.

2-tert-Butyl-5,6,7,8,9,10-hexahydrocyclohepta[b]indole

Directory of Open Access Journals (Sweden)

Janina Wobbe

2011-09-01

Full Text Available 2-tert-Butyl-5,6,7,8,9,10-hexahydrocyclohepta[b]indole was synthesized by reaction of cycloheptanone and (4-tert-butylphenylhydrazine hydrochloride in the presence of sodium acetate and sulfuric acid in glacial acetic acid via Fischer indole synthesis.

IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) (External Review Draft)

Science.gov (United States)

The IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) was released for external peer review in June 2017. EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) will conduct a peer review of the scientific basis supporting the ETB...

40 CFR 721.10193 - 1-Butanaminium, N-(3-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1-Butanaminium, N-(3-aminopropyl)-N...-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts. (a) Chemical substance and...-aminopropyl)-N-butyl-N-(2-carboxyethyl)-, N-coco acyl derivs., inner salts (PMN P-06-263, Chemical B; CAS No...

Catalytic Upgrading of Biomass-Derived Furfuryl Alcohol to Butyl Levulinate Biofuel over Common Metal Salts

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Lincai Peng

2016-09-01

Full Text Available Levulinate ester has been identified as a promising renewable fuel additive and platform chemical. Here, the use of a wide range of common metal salts as acid catalysts for catalytic upgrading of biomass-derived furfuryl alcohol to butyl levulinate was explored by conventional heating. Both alkali and alkaline earth metal chlorides did not lead effectively to the conversion of furfuryl alcohol, while several transition metal chlorides (CrCl3, FeCl3, and CuCl2 and AlCl3 exhibited catalytic activity for the synthesis of butyl levulinate. For their sulfates (Cr(III, Fe(III, Cu(II, and Al(III, the catalytic activity was low. The reaction performance was correlated with the Brønsted acidity of the reaction system derived from the hydrolysis/alcoholysis of cations, but was more dependent on the Lewis acidity from the metal salts. Among these investigated metal salts, CuCl2 was found to be uniquely effective, leading to the conversion of furfuryl alcohol to butyl levulinate with an optimized yield of 95%. Moreover, CuCl2 could be recovered efficiently from the resulting reaction mixture and remained with almost unchanged catalytic activity in multiple recycling runs.

Acceptability by community health workers in Senegal of combining community case management of malaria and seasonal malaria chemoprevention

DEFF Research Database (Denmark)

Tine, Roger Ck; Ndiaye, Pascal; Ndour, Cheikh T

2013-01-01

Community case management of malaria (CCMm) and seasonal malaria chemoprevention (SMC) are anti-malarial interventions that can lead to substantial reduction in malaria burden acting in synergy. However, little is known about the social acceptability of these interventions. A study was undertaken...... to assess whether combining the interventions would be an acceptable approach to malaria control for community health workers (CHWs)....

Colon cancer chemoprevention by a novel NO chimera that shows anti-inflammatory and antiproliferative activity in vitro and in vivo.

Science.gov (United States)

Hagos, Ghenet K; Carroll, Robert E; Kouznetsova, Tatiana; Li, Qian; Toader, Violeta; Fernandez, Patricia A; Swanson, Steven M; Thatcher, Gregory R J

2007-08-01

Chemopreventive agents in colorectal cancer possess either antiproliferative or anti-inflammatory actions. Nonsteroidal anti-inflammatory drugs (NSAID) and cyclooxygenase-2 inhibitors have shown promise, but are compromised by side effects. Nitric oxide donor NSAIDs are organic nitrates conjugated via a labile linker to an NSAID, originally designed for use in pain relief, that have shown efficacy in colorectal cancer chemoprevention. The NO chimera, GT-094, is a novel nitrate containing an NSAID and disulfide pharmacophores, a lead compound for the design of agents specifically for colorectal cancer. GT-094 is the first nitrate reported to reduce aberrant crypt foci (by 45%) when administered after carcinogen in the standard azoxymethane rat model of colorectal cancer. Analysis of proximal and distal colon tissue from 8- and 28-week rat/azoxymethane studies showed that GT-094 treatment reduced colon crypt proliferation by 30% to 69%, reduced inducible NO synthase (iNOS) levels by 33% to 67%, reduced poly(ADP-ribose)polymerase-1 expression and cleavage 2- to 4-fold, and elevated levels of p27 in the distal colon 3-fold. Studies in cancer cell cultures recapitulated actions of GT-094: antiproliferative activity and transient G(2)-M phase cell cycle block were measured in Caco-2 cells; apoptotic activity was examined but not observed; anti-inflammatory activity was seen in the inhibition of up-regulation of iNOS and endogenous NO production in lipopolysaccharide (LPS)-induced RAW 264.7 cells. In summary, antiproliferative, anti-inflammatory, and cytoprotective activity observed in vivo and in vitro support GT-094 as a lead compound for the design of NO chimeras for colorectal cancer chemoprevention.

Actinide-carbon bonds: insertion reactions of carbon monoxide, tert-butyl isocyanide, and tert-butyl cyanide into [(Me3Si)2N]2MCH2Si(Me)2NSiMe3

International Nuclear Information System (INIS)

Simpson, S.J.; Andersen, R.A.

1981-01-01

The thorium or uranium metallacycles [(Me 2 Si) 2 N] 2 MCH 2 Si(Me) 2 NSiMe 3 (I) react with tert-butyl cyanide to give the six-membered ring compounds [(Me 3 Si) 2 N] 2 MN = C(t-Bu)CH 2 Si(Me) 2 NSiMe 3 . The metallacycles (I) also react with the isoelectronic molecules tert-butyl isocyanide and carbon monoxide to give the unique five-membered ring compounds with exocyclic carbon-carbon double bonds, [(Me 3 Si) 2 N] 2 MXC(=CH 2 )Si(Me) 2 NSiMe 3 , where X is t-BuN or oxygen. The four-membered ring metallacycles (I) give simple coordination complexes of the type [(Me 3 Si) 2 N] 2 MCH 2 Si-(Me) 2 NSiMe 3 (N 3 SiMe 3 ) with trimethylsilyl azide

Esterification for butyl butyrate formation using Candida cylindracea lipase produced from palm oil mill effluent supplemented medium

Directory of Open Access Journals (Sweden)

Aliyu Salihu

2014-12-01

Full Text Available The ability of Candida cylindracea lipase produced using palm oil mill effluent (POME as a basal medium to catalyze the esterification reaction for butyl butyrate formation was investigated. Butyric acid and n-butanol were used as substrates at different molar ratios. Different conversion yields were observed according to the affinity of the produced lipase toward the substrates. The n-butanol to butyric acid molar ratio of 8 and lipase concentration of 75 U/mg gave the highest butyl butyrate formation of 63.33% based on the statistical optimization using face centered central composite design (FCCCD after 12 h reaction. The esterification potential of the POME based lipase when compared with the commercial lipase from the same strain using the optimum levels was found to show a similar pattern. It can be concluded therefore that the produced lipase possesses appropriate characteristics to be used as a biocatalyst in the esterification reactions for butyl butyrate formation.

Chemopreventive effects of free and bound phenolics associated to steep waters (nejayote) obtained after nixtamalization of different maize types.

Science.gov (United States)

Rojas-García, Carlos; García-Lara, Silverio; Serna-Saldivar, Sergio O; Gutiérrez-Uribe, Janet A

2012-03-01

Free and bound phenolics extracts from nejayote solids were obtained after optimally lime-cooking blue, normal white, red, normal yellow, high-carotenoid and quality protein maize types. The extraction yield ranged from 4.47 to 10.05%. Bound phenolics extracts had higher content of total phenolics, antioxidant activity and ferulic acid compared to the free phenolics extracts. In general, free phenolics extracts were less cytotoxic than the bound phenolics counterparts. Bound phenolics extracts had higher induction of quinone reductase (QR) and particularly the normal yellow nejayote exerted the highest chemopreventive index tested in Hepa1c1c7 cells. When tested for monofunctional phase 2 induction capacity in BPrc1 cells, the bound phenolics extracts of blue, normal white and quality protein nejayotes were better inducers than the normal yellow counterpart. Particularly, the free phenolics extract of the white maize nejayote induced BPrc1 cells QR and exerted a higher chemopreventive index compared to the bound phenolics extract. Therefore, the nejayote of the normal white maize was the best source of monofunctional phase 2 enzyme inducers.

Evaluation of chemopreventive potential of Strobilanthes crispus against colon cancer formation in vitro and in vivo.

Science.gov (United States)

Al-Henhena, Nawal; Khalifa, Shaden A M; Ying, Rozaida Poh Yuen; Ismail, Salmah; Hamadi, Riad; Shawter, Abdrabu N; Idris, Azila Mohd; Azizan, Ainnul; Al-Wajeeh, Nahla Saeed; Abdulla, Mahmood Ameen; El-Seedi, Hesham R

2015-11-25

With cancer being one of the major causes of death around the world, studies are ongoing to find new chemotherapeutic leads. There are common mechanisms for colorectal cancer (CRC) formation. Several are connected with oxidative stress-induced cell apoptosis and others are related to imbalanced homeostasis or intake of drugs/toxins. Plants that have been used for decades in folk and traditional medicine have been accepted as one of the commonest sources of discovered natural agents of cancer chemotherapy and chemoprevention. The aim was to study the antioxidant and chemopreventive effects of Strobilanthes crispus on colorectal cancer formation. Five groups of rats were injected subcutaneously with AOM, 15 mg/kg body weight, each once weekly for 2 weeks. The cancer group was continued on 10 % Tween-20 feeding for 8 weeks. The standard drug group was continued on 35 mg/kg 5-fluorouracil intraperitoneal injection twice a week for 8 weeks, and the experimental groups were continued on 250 and 500 mg/kg S. crispus extract oral feeding for 8 weeks, respectively. The normal group was injected subcutaneously with normal saline once a week for 2 weeks, followed by oral administration of 10 % Tween-20 for 8 weeks. All the rats were sacrificed after 10 weeks. The colons were evaluated grossly and histopathologically for aberrant crypt foci (ACF). Gene expression was performed for Bax, Bcl2, Defa24, Slc24a3, and APC genes by real-time PCR. S. crispus and its fractions were evaluated for their chemopreventive effects against human colorectal adenocarcinoma cell line HT29 and cytotoxicity for normal human colon epithelial cell line CCD 841, and the active fraction was assessed for its components. We observed significant decrease in total colonic ACF formation, malonaldehyde (MDA) and lactate dehydrogenase (LDH), increase in superoxide dismutase (SOD), up-regulation of APC, Bax and Slc24a3, and down-regulation of Defa24 and Bcl-2 in rats treated with Strobilanthes

Analysing chemical equilibrium conditions when studying butyl acetate synthesis

OpenAIRE

Álvaro Orjuela Londoño; Fernando Leiva Lenis; Luis Alejandro Boyacá Mendivelso; Gerardo Rodríguez Niño; Luis María Carballo Suárez

2010-01-01

This work studied the liquid phase of acetic acid and butyl alcohol esterification reaction (P atm = 560 mmHg),using an ion exchange resin (Lewatit K-2431) as catalyst. A set of assays were carried out for determining the effect of catalyst load, temperature and molar ratio (acid/alcohol) on chemical equilibrium constant. Components’ selective sorption on the resin matrix was noticed; its effect on equilibrium conditions was verified, by using different acid/alcohol starting ratios. A non-ide...

Antioxidants Inhibit Formation of 3-Monochloropropane-1,2-diol Esters in Model Reactions.

Science.gov (United States)

Li, Chang; Jia, Hanbing; Shen, Mingyue; Wang, Yuting; Nie, Shaoping; Chen, Yi; Zhou, Yongqiang; Wang, Yuanxing; Xie, Mingyong

2015-11-11

The capacities of six antioxidants to inhibit the formation of 3-monochloropropane-1,2 diol (3-MCPD) esters were examined in this study. Inhibitory capacities of the antioxidants were investigated both in chemical models containing the precursors (tripalmitoyl glycerol, 1,2-dipalmitoyl-sn-glycerol, monopalmitoyl glycerol, and sodium chloride) of 3-MCPD esters and in oil models (rapeseed oil and sodium chloride). Six antioxidants, butylated hydroxytoluene (BHT), butylated hydroxy anisole (BHA), tert-butyl hydroquinone (TBHQ), propyl gallate (PG), L-ascorbyl palmitate (AP), and α-tocopherol (VE), were found to exhibit inhibiting capacities on 3-MCPD ester formation both in chemical models and in oil models. TBHQ provided the highest inhibitory capacity both in chemical models and in oil models; 44% of 3-MCPD ester formation was inhibited in the presence of TBHQ (66 mg/kg of oil) after heating of rapeseed oil at 230 °C for 30 min, followed by PG and AP. BHT, BHA, and VE appeared to have weaker inhibitory abilities in both models. VE exhibited the lowest inhibition rate; 22% of 3-MCPD esters were inhibited in the presence of VE (172 mg/kg of oil) after heating of rapeseed oil at 230 °C for 30 min. In addition, the inhibition rates of PG and VE decreased dramatically with an increase in temperature or heating time. The results suggested that some antioxidants, such as TBHQ, PG, and AP, could be the potential inhibitors of 3-MCPD esters in practice.

Cloud-point extraction and reversed-phase high-performance liquid chromatography for the determination of synthetic phenolic antioxidants in edible oils.

Science.gov (United States)

Chen, Miao; Xia, Qinghai; Liu, Mousheng; Yang, Yaling

2011-01-01

A cloud-point extraction (CPE) method using Triton X-114 (TX-114) nonionic surfactant was developed for the extraction and preconcentration of propyl gallate (PG), tertiary butyl hydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) from edible oils. The optimum conditions of CPE were 2.5% (v/v) TX-114, 0.5% (w/v) NaCl and 40 min equilibration time at 50 °C. The surfactant-rich phase was then analyzed by reversed-phase high-performance liquid chromatography with ultraviolet detection at 280 nm, using a gradient mobile phase consisting of methanol and 1.5% (v/v) acetic acid. Under the studied conditions, 4 synthetic phenolic antioxidants (SPAs) were successfully separated within 24 min. The limits of detection (LOD) were 1.9 ng mL(-1) for PG, 11 ng mL(-1) for TBHQ, 2.3 ng mL(-1) for BHA, and 5.9 ng mL(-1) for BHT. Recoveries of the SPAs spiked into edible oil were in the range 81% to 88%. The CPE method was shown to be potentially useful for the preconcentration of the target analytes, with a preconcentration factor of 14. Moreover, the method is simple, has high sensitivity, consumes much less solvent than traditional methods, and is environment-friendly. Practical Application: The method established in this article uses less organic solvent to extract SPAs from edible oils; it is simple, highly sensitive and results in no pollution to the environment.

The influence of n-butyl mercaptan on acrylic compounds obtained winder γ-gamma radiation

International Nuclear Information System (INIS)

Ribeiro, Marcos S.; Parra, Duclerc F.; Lugao, Ademar B.

2013-01-01

The chain transfer agents play a key role in the production of polymers, as they allow better control of their molecular weight, among other functions. For this reason we performed this study to perform an analysis on the influence of n-butyl mercaptan in the reaction of compounds of ethyl methacrylate by varying the density and shrinkage of the samples. In the present study can be seen that n-butyl mercaptan, acts as transfer agent, which influences the reaction kinetics of composite acrylic, since it presence in the compound increased average density and contraction average. It is also possible to minimize the variability of the compound density, even if they are altered. Final products with improved properties homogeneously could be obtained. (author)

Radiogaschromatographic analysis of volatile products of the photolysis of the system bis-(tributyltin)-oxide-(butyl-l-14C)/cellulose

International Nuclear Information System (INIS)

Kloetzer, D.; Goerner, H.; Heise, K.H.

1979-01-01

Apparatus and method for separation and identification of the products of photochemical decomposition in the system bis(tributyltin)-oxide-(butyl-1- 14 C)/cellulose are described. Ultraviolet radiation causes the formation of n-butane- 14 C and n-octane- 14 C, i.e. 14 C-labelled butyl radicals splitting off from the tin organic compound are stabilized by reactions with H atoms from the photodecomposition of cellulose or by dimerization. (author)

Separation and determination of trace amounts of zinc, lead, cadmium and mercury in tap and Qaroun lake water using polyurethane foam functionalized with 4-hydroxytoluene and 4-hydroxyacetophenone

International Nuclear Information System (INIS)

Burham, N.; Abdel-Azeem, S.M.; El-Shahat, M.F.

2006-01-01

A stable chelating sorbent was synthesized by covalently linking 4-hydroxytoluene or 4-hydroxyacetophenone with the polyurethane foam (PUF) through -N=N- group. The synthesized chelating sorbents were characterized by IR and UV/vis measurements. The modified foams show excellent stability towards various solvents. Factors influencing the extraction process of Zn(II), Pb(II), Cd(II) and Hg(II) were studied and evaluated as a function of pH of metal ion solution and equilibration shaking time. The values of sorption capacity of metal ions (μg g -1 ) were determined with the two types of bonded foams. The two phenolic bonded foams were studied comparatively. The potential applications of the two newly synthesized foams for the removal and separation of the examined metal ions from two natural water samples (drinking tap water and Qaroun lake water at Fayoum City, Egypt) were investigated. Precision (assessed as a relative standard deviation, R.S.D.) was also evaluated and found to be ≤7.3% (N = 5) with a detection limit under 0.46 μg L -1

Separation and determination of trace amounts of zinc, lead, cadmium and mercury in tap and Qaroun lake water using polyurethane foam functionalized with 4-hydroxytoluene and 4-hydroxyacetophenone

Energy Technology Data Exchange (ETDEWEB)

Burham, N. [Chemistry Department, Faculty of Science, Fayoum University, Fayoum City (Egypt)]. E-mail: n_burham@yahoo.com; Abdel-Azeem, S.M. [Chemistry Department, Faculty of Science, Fayoum University, Fayoum City (Egypt); El-Shahat, M.F. [Chemistry Department, Faculty of Science, Ain-Shams University, Cairo (Egypt)

2006-10-10

A stable chelating sorbent was synthesized by covalently linking 4-hydroxytoluene or 4-hydroxyacetophenone with the polyurethane foam (PUF) through -N=N- group. The synthesized chelating sorbents were characterized by IR and UV/vis measurements. The modified foams show excellent stability towards various solvents. Factors influencing the extraction process of Zn(II), Pb(II), Cd(II) and Hg(II) were studied and evaluated as a function of pH of metal ion solution and equilibration shaking time. The values of sorption capacity of metal ions ({mu}g g{sup -1}) were determined with the two types of bonded foams. The two phenolic bonded foams were studied comparatively. The potential applications of the two newly synthesized foams for the removal and separation of the examined metal ions from two natural water samples (drinking tap water and Qaroun lake water at Fayoum City, Egypt) were investigated. Precision (assessed as a relative standard deviation, R.S.D.) was also evaluated and found to be {<=}7.3% (N = 5) with a detection limit under 0.46 {mu}g L{sup -1}.

New evidence for primordial action site of Fluazifop-P-butyl on Acanthospermum hispidum seedlings: From the effects on chlorophyll fluorescence characteristics and histological observation.

Science.gov (United States)

Shang, Yuhong; Yang, Congjun; Liu, Zhihang; Song, Jiqing; Li, Pingliang; Li, Lingxu; Zhou, Fei; Xin, Hua; Wan, Fanghao; Matsumoto, Hiroshi; Luo, Xiaoyong

2017-10-01

Acanthospermum hispidum DC, an Asteraceae weed species, was very susceptible to fluazifop-P-butyl, but tolerant to other aryloxyphenoxypropionate herbicides, such as haloxyfop-P-methyl. However, other Asteraceae weeds including Bidens pilosa were all tolerant to fluazifop-P-butyl. Membrane lipid peroxidation by increasing the levels of reactive oxygen species (ROS) was proposed as an action mechanism of fluazifop-P-butyl in A. hispidum. To further clarify the primordial action site of fluazifop-P-butyl in this species, the effects on chlorophyll fluorescence characteristics and cytohistology of apical meristems were studied. Chlorophyll fluorescence characteristics (CFC) in sensitive A. hispidum seedlings were markedly affected by 10μM fluazifop-P-butyl, with the dark fluorescence yield (Fo), maximal fluorescence yield (Fm), maximal PS II quantum yield (Fv/Fm), effective photosystem II (PS II) quantum yield [Y(II)], and quantum yield of regulated energy dissipation [Y(NPQ)] declining, quantum yield of nonregulated energy dissipation [Y(NO)] rising, but these measures were not affected in Bidens pilosa. The effects of fluazifop-P-butyl on chlorophyll fluorescence properties were observed on the growing point before the mature leaves by about 4-6h. Haloxyfop-P-methyl, a control herbicide, had no effects on CFC of either A. hispidum or B. pilosa. In addition, damage to apical meristem cells of A. hispidum was observed at 6 HAT prior to changes in chlorophyll fluorescence parameters suggesting that the primary action site of fluazifop-P-butyl in this species is in the apical meristem and the effects on CFC may be the results of secondary action. Copyright © 2017 Elsevier Inc. All rights reserved.

Black tea: Phytochemicals, cancer chemoprevention, and clinical studies.

Science.gov (United States)

Singh, Brahma N; Rawat, A K S; Bhagat, R M; Singh, B R

2017-05-03

Tea (Camellia sinensis L.) is the most popular, flavored, functional, and therapeutic non-alcoholic drink consumed by two-thirds of the world's population. Black tea leaves are reported to contain thousands of bioactive constituents such as polyphenols, amino acids, volatile compounds, and alkaloids that exhibit a range of promising pharmacological properties. Due to strong antioxidant property, black tea inhibits the development of various cancers by regulating oxidative damage of biomolecules, endogenous antioxidants, and pathways of mutagen and transcription of antioxidant gene pool. Regular drinking of phytochemicals-rich black tea is linked to regulate several molecular targets, including COX-2, 5-LOX, AP-1, JNK, STAT, EGFR, AKT, Bcl2, NF-κB, Bcl-xL, caspases, p53, FOXO1, TNFα, PARP, and MAPK, which may be the basis of how dose of black tea prevents and cures cancer. In vitro and preclinical studies support the anti-cancer activity of black tea; however, its effect in human trails is uncertain, although more clinical experiments are needed at molecular levels to understand its anti-cancer property. This review discusses the current knowledge on phytochemistry, chemopreventive activity, and clinical applications of black tea to reveal its anti-cancer effect.

IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) (External Review Draft, 2009)

Science.gov (United States)

EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of ethyl tertiary butyl ether (ETBE) that when finalized will appear on the Integrated Risk Information System (IRIS) database.

Combined prenatal and postnatal butyl paraben exposure produces autism-like symptoms in offspring: comparison with valproic acid autistic model.

Science.gov (United States)

Ali, Elham H A; Elgoly, Amany H Mahmoud

2013-10-01

The aim of this work is to evaluate the impact of butyl paraben (BP) in brain of the pups developed for mothers administered BP from early pregnancy till weaning and its effect on studying the behavior, brain neurotransmitters and brain derived neurotrophic factor BDNF via comparing the results with valproic acid (VA) autistic-rat model preparing by a single oral injection dose of VA (800 mg/kg b.wt) at the 12.5 days of gestation. Butyl paraben was orally and subcutaneously administered (200 mg/kg b.wt) to pregnant rats from gestation day 1 to lactation day 21. The offspring male rats were subjected at the last 3 days of lactation to Morris water maze and three chamber sociability test then decapitated and the brain was excised and dissected to the cortex, hippocampus, cerebellum, midbrain and pons for the determination of norepinephrine, dopamine and serotonin (NE, DA and 5-HT) and cortex amino acids and whole brain BDNF. The results showed similar social and learning and memory behavioral deficits in VA rat model and the butyl paraben offspring in comparison with the controls. Also, some similar alterations were observed in monoamine content, amino acids and BDNF factor in the autistic-like model and butyl paraben offspring in comparison with the controls. The alterations were recorded notably in hippocampus and pons NE, midbrain DA, hippocampus and midbrain 5-HT, and frontal cortex GABA and asparagine. These data suggest that prenatal exposure to butyl paraben induced neuro-developmental disorders similar to some of the neurodevelopmental disorders observed in the VA model of autism. © 2013 Elsevier Inc. All rights reserved.

Assessment, measurement and correlation of (vapour + liquid) equilibrium of (carbon dioxide + butyl, isobutyl, and amyl formate) systems

International Nuclear Information System (INIS)

Shen, Yanshu; Zheng, Danxing; Li, Xinru; Li, Yun

2013-01-01

Highlights: • Selected three formates that have relative perfect absorption performance for CO 2 . • Measured the VLE data of CO 2 + butyl, isobutyl, and amyl formates systems. • Correlated the VLE data by using PR EOS with two mixing rules and SRK EOS with one mixing rule. • Concluded amyl formate has potential research value as CO 2 physical absorbent. -- Abstract: In this work, three formates (butyl, isobutyl, and amyl formate) were considered as relative perfect CO 2 absorption performance based on the excess Gibbs function as the thermodynamics criterion. An online static-analytical method was used to measure the (vapour + liquid) equilibrium (VLE) data for the CO 2 + butyl, isobutyl, and amyl formates under the pressure of (0.2 to 6) MPa and the temperatures at a range from (283.15 to 343.15) K. Then the VLE data were correlated by Peng–Robinson (PR) equation of state (EOS) with classic mixing rule, PR EOS with Wong–Sandler (WS) mixing rule and Soave–Redlich–Kwong (SRK) EOS with classic mixing rule. It is shown that SRK EOS is comparatively appropriate for CO 2 + butyl formate binary system. Both PR EOS with classic mixing rule and SRK EOS can be used to correlate the binary systems of CO 2 + isobutyl, amyl formate. It is found that the solubility order of three formates for CO 2 from high to low is arranged as CO 2 + amyl formate > CO 2 + butyl formate > CO 2 + isobutyl formate, showing the system of CO 2 + amyl formate has the best absorption performance. By comparison, it indicates that formates have a greater solubility for CO 2 than acetates on the condition of the same temperature and pressure. In addition, the thermophysical properties, mole absorption and mass absorptive amount of several industrial absorbents were assessed and the absorption performance of amyl formate for CO 2 is better than other physical absorbents. Thus, the study concluded that amyl formate has potential research value as physical absorbent for CO 2 capture

A Rare Case of Retrogastric Abscess Occurring Six Months after N-Butyl-2-Cyanoacrylate Injection into Gastric Varices

Directory of Open Access Journals (Sweden)

Ikram Hussain

2018-01-01

Full Text Available Background. Injection with N-butyl-2-cyanoacrylate is a proven and successful therapeutic modality for treatment of patients with bleeding gastric varices. However, a variety of complications have also been associated with its use. Here, we report a rare case of retrogastric abscess which occurred almost six months after this therapy. This abscess was attributed to the hampered microbial clearance caused by the venous obliterations from N-butyl-2-cyanoacrylate. The abscess was successfully treated with 3 months of antibiotics.

IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) (Interagency Science Consultation Draft)

Science.gov (United States)

In September 2016, EPA released the draft IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) for public comment and discussion. The draft assessment was reviewed internally by EPA and by other federal agencies and White House Offices before public release. Consistent ...

Sources and historical record of tin and butyl-tin species in a Mediterranean bay (Toulon Bay, France).

Science.gov (United States)

Pougnet, Frédérique; Schäfer, Jörg; Dutruch, Lionel; Garnier, Cédric; Tessier, Erwan; Dang, Duc Huy; Lanceleur, Laurent; Mullot, Jean-Ulrich; Lenoble, Véronique; Blanc, Gérard

2014-05-01

Concentrations of inorganic tin (Sn(inorg)), tributyltin (TBT) and its degradation products dibutyltin (DBT) and monobutyltin (MBT) were measured in surface sediments and in two cores from the Toulon Bay, hosting the major French military harbour. Anticipating planned dredging, the aim of the present work is to map and evaluate for the first time the recent and historic contamination of these sediments by inorganic and organic Sn species derived from antifouling paints used for various naval domains including military, trade, tourism and leisure. Tin and butyl-Sn concentrations in the bay varied strongly (4 orders of magnitude), depending on the site, showing maximum values near the shipyards. The concentrations of total Sn (1.3-112 μg g(-1)), TBT (product Sn(inorgBT) is by far the dominant species after 10-12 half-life periods and (c) using recent data to reliably assess former TBT contamination requires the use of a modified butyl-Sn degradation index BDI(mod). Resuspension of extremely contaminated subsurface sediments by the scheduled dredging will probably result in mobilization of important amounts of butyl-Sn species.

Structure and properties of oil palm-based nanocellulose reinforced chitosan nanocomposite for efficient synthesis of butyl butyrate.

Science.gov (United States)

Elias, Nursyafiqah; Chandren, Sheela; Attan, Nursyafreena; Mahat, Naji Arafat; Razak, Fazira Ilyana Abdul; Jamalis, Joazaizulfazli; Wahab, Roswanira Abdul

2017-11-15

In this study, nanocellulose (NC) was successfully extracted from oil palm frond leaves (OPFL) using a combination of bleaching, alkaline treatment and acid hydrolysis. X-ray diffractogram revealed the extracted NC was crystalline with a crystallinity index of 70.2%. This indicates its suitability as nano-fillers for preparing the chitosan/nanocellulose (CS-NC) supports to immobilize Candida rugosa lipase (CRL) to produce the CRL/CS-NC biocatalysts. FTIR, FESEM and TGA characterizations of the CRL/CS-NC confirm the CRLs were successfully conjugated to the CS-NC supports. The air-dried CS-NC supports gave satisfactory immobilization of the CRLs (5.2mg/g) with the resultant CRL/CS-NCs catalysed conversions of ≥80% of butyl butyrate within 6h. Time course reaction profile revealed that 76.3% butyl butyrate conversion was achieved at 4h immobilization time using 3mg/mL of CRL/CS-NCs. NMR analyses on the purified butyl butyrate confirmed that the ester was successfully synthesized. Copyright © 2017 Elsevier Ltd. All rights reserved.

{2,6-Bis[(di-tert-butyl-phosphino)-methyl]-phenyl}chloridonickel(II).

Science.gov (United States)

Boro, Brian J; Dickie, Diane A; Goldberg, Karen I; Kemp, Richard A

2008-09-20

In the title compound, [Ni(C(24)H(43)P(2))Cl], the Ni atom adopts a distorted square-planar geometry, with the P atoms of the 2,6-bis-[(di-tert-butyl-phosphino)meth-yl]phenyl ligand trans to one another. The P-Ni-P plane is twisted out of the plane of the aromatic ring by 21.97 (6)°.

Enhanced diisobutene production in the presence of methyl tertiary butyl ether

Science.gov (United States)

Smith, L.A. Jr.

1983-03-01

In the liquid phase reaction of isobutene in the presence of resin cation exchange resins with itself in a C[sub 4] hydrocarbon stream to form dimers, the formation of higher polymers, oligomers, and co-dimer by-products is suppressed by the presence of 0.0001 to 1 mole per mole of isobutene of methyl tertiary butyl ether. 1 fig.

The Chemopreventive Phytochemical Moringin Isolated from Moringa oleifera Seeds Inhibits JAK/STAT Signaling.

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Carina Michl

Full Text Available Sulforaphane (SFN and moringin (GMG-ITC are edible isothiocyanates present as glucosinolate precursors in cruciferous vegetables and in the plant Moringa oleifera respectively, and recognized for their chemopreventive and medicinal properties. In contrast to the well-studied SFN, little is known about the molecular pathways targeted by GMG-ITC. We investigated the ability of GMG-ITC to inhibit essential signaling pathways that are frequently upregulated in cancer and immune disorders, such as JAK/STAT and NF-κB. We report for the first time that, similarly to SFN, GMG-ITC in the nanomolar range suppresses IL-3-induced expression of STAT5 target genes. GMG-ITC, like SFN, does not inhibit STAT5 phosphorylation, suggesting a downstream inhibitory event. Interestingly, treatment with GMG-ITC or SFN had a limited inhibitory effect on IFNα-induced STAT1 and STAT2 activity, indicating that both isothiocyanates differentially target JAK/STAT signaling pathways. Furthermore, we showed that GMG-ITC in the micromolar range is a more potent inhibitor of TNF-induced NF-κB activity than SFN. Finally, using a cellular system mimicking constitutive active STAT5-induced cell transformation, we demonstrated that SFN can reverse the survival and growth advantage mediated by oncogenic STAT5 and triggers cell death, therefore providing experimental evidence of a cancer chemopreventive activity of SFN. This work thus identified STAT5, and to a lesser extent STAT1/STAT2, as novel targets of moringin. It also contributes to a better understanding of the biological activities of the dietary isothiocyanates GMG-ITC and SFN and further supports their apparent beneficial role in the prevention of chronic illnesses such as cancer, inflammatory diseases and immune disorders.

Aspirin as a Chemopreventive Agent for Cancer: a New Hope?

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Isnatin Miladiyah

2016-01-01

Full Text Available Introduction: inflammation has been shown to play a major role in the pathogenesis of cancer. Inflammatory process activates the immune system through pro-inflammatory mediators and subsequent triggers transformation into malignant cells. Some tumors or cancers has been associated with chronic infections, such as hepatitis B and C viruses (hepatocellular carcinoma, human papilloma virus (cervical cancer, Helicobacter pylori (gastric cancer and lymphoma, and prostatitis (prostate cancer. A considerable study have investigated the benefits of aspirin for the prevention and treatment of cancer or tumors. Objectives: This paper aims to describe the relationship between inflammation and cancer incidence, so that use of aspirin as an anti-inflammatory agent is a rational choice in the treatment and prevention of cancer. Conclusion: Aspirin potential for chemoprevention of various types of cancer. Considering the high risk of side effects of aspirin, aspirin is not intended as a routine therapy to prevent the occurrence of cancer.

Oxidative DNA damage in male wistar rats exposed to di-n-butyl phthalate

DEFF Research Database (Denmark)

Wellejus, A.; Dalgaard, Majken; Loft, S.

2002-01-01

Dialkyl phthalate esters are used in the plastic industry and widely distributed in the environment, Previously, it has been shown that di-n-butyl phthalate (DBP) produces testicular atrophy and liver enlargement in rodents, and the mechanisms behind this could involve reactive oxygen species (ROS...

Morphology and film formation of poly(butyl methacrylate)-polypyrrole core-shell latex particles

NARCIS (Netherlands)

Huijs, F; Lang, J

Core-shell latex particles made of a poly(butyl methacrylate) (PBMA) core and a thin polypyrrole (PPy) shell were synthesized by two-stage polymerization. In the first stage, PBMA latex particles were synthesized in a semicontinuous process by free-radical polymerization. PBMA latex particles were

5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrapropynyloxy-2,8,14,20-tetrathiacalix[4]arene

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Xiang-Gao Meng

2009-12-01

Full Text Available The title compound [systematic name: 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrapropynyloxy-2,8,14,20-tetrathiacalix[4]arene], C52H56O4S4, is an alkylated product bearing four propyne groups at the lower rim of a 5,11,17,23-tetra-tert-butyl-tetrathiacalix[4]arene. The molecule is located on a crystallographic twofold rotation axis, running through two S atoms and perpendicular to the long axis of the molecule. The four propyne groups, located in an alternate fashion above and below the mean plane of the four S atoms, are almost parallel to the calixarene long axis. The dihedral angle between the two crystallographically independent benzene rings is 86.77 (14°. Two tert-butyl groups are disordered over two positions with site occupancies of 0.59 (2 and 0.41 (2.

Effect of tert-Butyl Functionalization on the Photoexcited Decay of a Fe(II)-N-Heterocyclic Carbene Complex

DEFF Research Database (Denmark)

Pápai, Mátyás Imre; Penfold, Thomas J.; Møller, Klaus Braagaard

2016-01-01

-vibronic quantum dynamics simulations on the Fe-N-heterocyclic carbene complex, [Fe(btbip)2]2+ (btbip = 2,6-bis(3-tert-butyl-imidazole-1-ylidene)pyridine). The results demonstrate that a relatively minor structural change compared to its parent complex, [Fe(bmip)2]2+ (bmip = 2,6-bis(3-methyl-imidazole-1-ylidene....... This occurs because the tert-butyl functionalization stabilizes the 1MC states, enabling the 1,3MLCT → 1MC population transfer to occur close to the Franck-Condon geometry, making the conversion very efficient. Subsequently, a spin cascade occurs within the MC manifold, leading to the population of triplet...

Simultaneous /sup 99m/Tc-p-butyl-IDA and 131I-rose bengal scintigraphy in neonatal jaundice

International Nuclear Information System (INIS)

Collier, B.D.; Treves, S.; Davis, M.A.; Heyman, S.; Subramanian, G.; McAfee, J.G.

1980-01-01

Eight neonates with jaundice were studied simultaneously with /sup 99m/Tc-p-butyl-IDA and 131 I-rose bengal. Due to physical decay, /sup 99m/Tc-p-butyl-IDA failed to demonstrate delayed excretion through the patent extrahepatic biliary tract in 3 of 5 patients with concomitant hepatitis; 131 I-rose bengal showed small-bowel activity in all 5. Neither agent demonstrated small-bowel activity in 3 neonates with extrahepatic biliary atresia. Based on this clinical trial, 131 I-rose bengal remains the radiopharmaceutical of choice for distinguishing between hepatitis and biliary atresia in these patients

Chemoprevention of colorectal cancer by black raspberry anthocyanins involved the modulation of gut microbiota and SFRP2 demethylation.

Science.gov (United States)

Chen, Lili; Jiang, Bowen; Zhong, Chunge; Guo, Jun; Zhang, Lihao; Mu, Teng; Zhang, Qiuhua; Bi, Xiuli

2018-03-08

Freeze-dried black raspberry (BRB) powder is considered as a potential cancer chemopreventive agent. In this study, we fed azoxymethane (AOM)/dextran sodium sulfate (DSS)-treated C57BL/6J mice with a diet containing BRB anthocyanins for 12 weeks, and this led to a reduction in colon carcinogenesis. These animals had consistently lower tumor multiplicity compared with AOM/DSS-treated mice not receiving BRB anthocyanins. In AOM/DSS-treated mice, the number of pathogenic bacteria, including Desulfovibrio sp. and Enterococcus spp., was increased significantly, whereas probiotics such as Eubacterium rectale, Faecalibacterium prausnitzii and Lactobacillus were dramatically decreased, but BRB anthocyanins supplement could reverse this imbalance in gut microbiota. BRB anthocyanins also caused the demethylation of the SFRP2 gene promoter, resulting in increased expression of SFRP2, both at the mRNA and protein levels. Furthermore, the expression levels of DNMT31 and DNMT3B, as well as of p-STAT3 were downregulated by BRB anthocyanins in these animals. Taken together, these results suggested that BRB anthocyanins could modulate the composition of gut commensal microbiota, and changes in inflammation and the methylation status of the SFRP2 gene may play a central role in the chemoprevention of CRC.

Chemopreventive Effects of Magnesium Chloride Supplementation on Hormone Independent Prostate Cancer Cells

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Elsa Quiroz

2016-01-01

Full Text Available Background: Lifestyle significantly impacts the risk factors associated with prostate cancer, out of which diet appears to be the most influential. An emerging chemopreventive approach, which involves the adequate intake of dietary constituents, has shown great potential in preventing the occurrence or progression of cancer. Magnesium is known to be an essential cofactor for more than 300 enzymatic processes, and is responsible for the regulation of various cellular reactions in the body. A plethora of studies have shown evidence that changes in the intracellular levels of magnesium could contribute to cell proliferation and apoptosis in some normal and malignant cells. The aim of the study was to investigate the effects of magnesium chloride (MgCl2 in DU-145 prostate cancer cells. Methodology: Cultured DU-145 cells were subjected to graded concentrations or doses (50-500 µM of MgCl2 for 48 hours. The cell viability was assessed using MTT and Resazurin reduction assays. NBT assay was also used to assess the treatment-induced intracellular ROS levels. Acridine Orange/Ethidium Bromide (AcrO/EtBr and Rh123/EtBr fluorescent stains were used to assess the cell death type and mitochondrial membrane potential (Δψm respectively. Results: The results revealed a dose-dependent decrease (P < 0.05 in cell viability in treated DU-145 cells after 48 hours. The NBT assay also revealed a dose dependent biphasic response (P < 0.05 in intracellular levels of ROS. There was a drop (P < 0.05 in ROS levels in all groups except at 100 µM, where ROS level was higher than the control. Apoptosis was the primary mode of cell death as observed in the fluorescence analysis. Conclusion: Our finding suggests that MgCl2 may be potentially chemopreventive for prostate cancer. This justifies further studies into its mechanism of action in DU-145 and other prostate cancer cell types.

Drugs with potential chemopreventive properties in relation to epithelial ovarian cancer--a nationwide case-control study.

Science.gov (United States)

Baandrup, Louise

2015-07-01

Ovarian cancer has a poor prognosis because the disease in the majority of patients is diagnosed at an advanced stage as a result of nonspecific symptoms and lack of efficient screening methods. Because of the poor prognosis of ovarian cancer and the challenge of early detection of the disease, identification of protective factors is important. It has been suggested that some commonly used drugs may have a protective effect against cancer, including ovarian cancer; however, the literature on chemopreventive measures for ovarian cancer is sparse and the results are inconclusive. Most previous studies have substantial methodological constraints, including limited study size and self-reporting of drug use, which introduces potential recall bias and misclassification. This PhD thesis includes a nationwide case-control study to evaluate associations between use of drugs with potential chemopreventive properties and risk of epithelial ovarian cancer. The study is nested in the entire Danish female population using data from the following nationwide registries: the Danish Cancer Registry, the Danish Civil Registration System, the Danish Prescription Registry, the Danish National Patient Register, and registries in Statistics Denmark on fertility, education, and income. Information from the included registries is linked by use of the unique personal identification number assigned to all Danish citizens. The cases were all women in Denmark with epithelial ovarian cancer diagnosed during 2000-2009 (Paper 1) and 2000-2011 (Papers 2 and 3), identified in the Cancer Registry. Age-matched female population controls were randomly selected from the Civil Registration System by risk-set sampling. We required that cases and controls have no history of cancer (except non-melanoma skin cancer) and that controls not previously have undergone bilateral oophorectomy or salpingo-oophorectomy. The total study population comprised 3741 epithelial ovarian cancer cases and 50,576 controls in

Ureteric Embolization for Lower Urinary Tract Fistulae: Use of Two Amplatzer Vascular Plugs and N-Butyl Cyanoacrylate Employing the 'Sandwich' Technique

Energy Technology Data Exchange (ETDEWEB)

Saad, Wael E. A., E-mail: ws6r@virginia.edu; Kalagher, S.; Turba, U. C.; Sabri, S. S.; Park, A.-W.; Stone, J.; Angle, J. F.; Matsumoto, A. H. [University of Virginia Health System, Department of Radiology and Medical Imaging, Division of Vascular Interventional Radiology (United States)

2013-08-01

PurposeThis study describes and evaluated the effectiveness of occluding distal ureters in the clinical setting of urinary vaginal (vesicovaginal or enterovesicovaginal) fistulae utilizing a new technique which combines Amplatzer vascular plugs and N-butyl cyanoacrylate.MaterialsThis is a retrospective study (January 2007-December 2010) of patients with urinary-vaginal fistulae undergoing distal ureter embolization utilizing an Amplatzer- N-butyl cyanoacrylate-Amplatzer sandwich technique. An 8-12-mm type-I or type-II Amplatzer vascular plug was delivered using the sheath and deployed in the ureter distal to the pelvic brim. Instillation of 0.8-1.5 cc of N-butyl cyanoacrylate into ureter proximal to the Amplatzer plug was performed. This was followed by another set of 8-12-mm type-I or type-II Amplatzer vascular plugs in a technique referred to as the 'sandwich technique.'ResultsFive ureters in three patients were occluded utilizing the above-described technique during the 4-year study period. Mean maximum size Amplatzer used per ureter was 10.8 mm (range, 8-12). One ureter required three Amplatzer plugs and the rest required two. Two patients (3 ureters) were clinically successful with complete resolution of symptoms in 36-48 h. The third patient (2 ureters) was partly successful and required a second Amplatzer- N-butyl cyanoacrylate sandwich technique embolization. The mean clinical follow-up was 11.3 months (range, 1.7-29.2).ConclusionsThe Amplatzer- N-butyl cyanoacrylate-Amplatzer sandwich technique for occluding the distal ureter is safe and effective with a quick (probably due to the N-butyl cyanoacrylate) and durable (probably due to the Amplatzer plugs) clinical response.

Characterization of Z-RAFT star polymerization of butyl acrylate by size-exclusion chromatography

NARCIS (Netherlands)

Boschmann, D.; Edam, R.; Schoenmakers, P.J.; Vana, P.

2009-01-01

Z-RAFT star polymerization of butyl acrylate using multifunctional trithiocarbonate-type RAFT agents carrying methyl propionate as the leaving group were used to form star polymers having 3, 4, and 6 arms. The polymerizations showed well controlled behavior up to high monomer conversions. By using a

Chemopreventive effects of NSAIDs as inhibitors of cyclooxygenase-2 and inducers of apoptosis in experimental lung carcinogenesis.

Science.gov (United States)

Setia, Shruti; Vaish, Vivek; Sanyal, Sankar Nath

2012-07-01

Roles of cyclooxygenase (COX) enzyme and intrinsic pathway of apoptosis have been explored for the chemopreventive effects of non-steroidal anti-inflammatory drugs (NSAIDs) on 9,10-dimethyl benz(a)anthracene (DMBA)-induced lung cancer in rat model. 16 weeks after the administration of DMBA, morphological analysis revealed the occurrences of tumours and lesions, which were regressed considerably with the co-administration of indomethacin and etoricoxib, the two NSAIDs under investigation. DMBA group was marked by hyperplasia and dysplasia as observed by histological examination, and these features were corrected to a large extent by the two NSAIDs. Elevated levels of COX-2 were seen in the DMBA group, the enzyme responsible for prostaglandin synthesis during inflammation and cancer, whilst the expression of the constitutive isoform, COX-1, was equally expressed in all the groups. Apoptosis was quantified by studying the activities of apaf-1, caspase-9, and 3 by immunofluorescence and western blots. Their activities were found to diminish in the DMBA-treated animals as compared to the other groups. Fluorescent co-staining of the isolated broncho-alveolar lavage cells showed reduced number of apoptotic cells in the DMBA group, indicating decrease in apoptosis after carcinogen administration. The present results thus suggest that the mechanism of cancer chemoprevention of NSAIDs may include the suppression of COX-2 and the induction of apoptosis.

[Photometric determination of butyl "aeroflot" flotation agent (sodium dibutyl dithiophosphate) in the air of work zone and skin washings].

Science.gov (United States)

Dorogova, V B; Kucheriavykh, E I; Sokolova, T V

1989-01-01

Photometric procedure of butyl "aeroflot" identification in the work zone air and in wash-out from workers' integument was developed, The procedure was based on the formation of yellow- and orange-dyed copper dibutyl dithiophosphate under butyl "aeroflot" interaction with copper sulphate with the subsequent photometry of dyed solutions for the wavelength of 420 nm in the 10-mm cell. Buffer solution with pH-9.2 was used as an absorbing solution for the workplace air sampling and integument wash-out.

A study of butyl acetate synthesis. 4-reaction kinetics

OpenAIRE

Álvaro Orjuela Londoño; Fernando Leiva Lenis; Luis Alejandro Boyacá Mendivelso; Gerardo Rodríguez Niño; Luis María Carballo Suárez

2006-01-01

This work was aimed at studying liquid-phase acetic acid and butyl alcohol esterification reaction (P atm =0.76 Bar),using an ion exchange resin (Lewatit K-2431) as catalyst. The effect of the absence of internal and external mass transport on catalyst particles was established in the research conditions used here. A set of assays to determine the effect of catalyst load (0.5%, 1%, 2% w/w) temperature (73°C, 80°C, 87°C) and molar ratio (1:2, 1:1, 2:1 acid/alcohol) on reaction rate was carrie...

Preclinical Cancer Chemoprevention Studies Using Animal Model of Inflammation-Associated Colorectal Carcinogenesis

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Takuji [Cytopatholgy Division, Tohkai Cytopathology Institute, Cancer Research and Prevention (TCI-CaRP), 5-1-2 Minami-uzura, Gifu 500-8285 (Japan); Department of Tumor Pathology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan)

2012-07-16

Inflammation is involved in all stages of carcinogenesis. Inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease is a longstanding inflammatory disease of intestine with increased risk for colorectal cancer (CRC). Several molecular events involved in chronic inflammatory process are reported to contribute to multi-step carcinogenesis of CRC in the inflamed colon. They include over-production of free radicals, reactive oxygen and nitrogen species, up-regulation of inflammatory enzymes in arachidonic acid biosynthesis pathway, up-regulation of certain cytokines, and intestinal immune system dysfunction. In this article, firstly I briefly introduce our experimental animal models where colorectal neoplasms rapidly develop in the inflamed colorectum. Secondary, data on preclinical cancer chemoprevention studies of inflammation-associated colon carcinogenesis by morin, bezafibrate, and valproic acid, using this novel inflammation-related colorectal carcinogenesis model is described.

Multiple cutaneous leiomyomas: Pain relief with pulsed hysocine butyl bromide

Directory of Open Access Journals (Sweden)

Kaliyadan Feroze

2009-01-01

Full Text Available A 35-year-old male patient presented to our outpatient department, complaining of multiple, raised skin lesions on the forehead and back, associated with intermittent pain, especially on exposure to cold. A diagnosis of cutaneous leiomyoma (type 2 segmental was made, which was confirmed by skin biopsy. The patient was started on a trial of pulsed Hyoscine Butyl bromide tablets, following which the patient had significant relief from pain associated with the lesions.

Chemopreventive effects of embelin and curcumin against N-nitrosodiethylamine/phenobarbital-induced hepatocarcinogenesis in Wistar rats.

Science.gov (United States)

Sreepriya, M; Bali, Geetha

2005-09-01

The effects of embelin (50 mg/kg/day), a benzoquinone derivative of Embelia ribes, and the effects of curcumin (100 mg/kg/day), the active principle of Curcuma longa, against N-nitrosodiethylamine (DENA)-initiated and phenobarbital (PB)-promoted hepatocarcinogenesis were studied in Wistar rats. They were able to prevent the induction of hepatic hyper plastic nodules, body weight loss, increase in the levels of hepatic diagnostic markers, and hypoproteinemia induced by DENA/PB treatment. Hence, results of our study suggest the possible chemopreventive effects of embelin (EMB) and curcumin (CUR) against DENA/PB-induced hepatocarcinogenesis in Wistar rats.

Application of butyl alcohol bacteria for the fermentation of nonnutritive raw materials

Energy Technology Data Exchange (ETDEWEB)

Nakhamanovich, B M; Senkevich, V V; Yarovenko, V L

1961-01-01

Materials like corncobs after hydrolysis can be economically fermented by using bacteria which support a butyl alcohol-acetone fermentation. Best results are obtained if (NH/sub 4/)/sub 2/SO/sub 4/ and superphosphate are added to the fermentation liquor. Analyses are presnted of the hydrolzates (alcohols, formic acid, 2-furaldehyde, and reducing sugars) and of the final products.

IRIS Toxicological Review of Ethylene Glycol Mono-Butyl Ether (Egbe) (Interagency Science Discussion Draft)

Science.gov (United States)

EPA released the draft report, Toxicological Review for Ethylene Glycol Mono-Butyl Ether , that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process. Comments received from ot...

DERMAL, ORAL, AND INHALATION PHARMACOKINETICS OF METHYL TERTIARY BUTYL ETHER (MTBE) IN HUMAN VOLUNTEERS

Science.gov (United States)

Methyl tertiary butyl ether (MTBE), a gasoline additive, used to increase octane and reduce carbon monoxide emissions and ozone precursors has contaminated drinking water leading to exposure by oral, inhalation, and dermal routes. To determine its dermal, oral, and inhalation ki...

Iodine catalyzed and tertiary butyl ammonium bromide promoted p reparation of b enzoxazaphosphininyl phenylboronates

Directory of Open Access Journals (Sweden)

K. R. Kishore K. Reddy,

2009-05-01

Full Text Available Benzoxazaphosphininyl Phenylboronates were prepared by O-Phosphorylation of potassium salt ofphenylboronic acid with cyclic phosphoromonochloridates in the presence of stoichiometric amount of Iodineand catalytic amount of tertiary butyl ammonium bromide at 50-60 °C in dry toluene.

Simultaneous determination of triacetin, acetic ether, butyl acetate and amorolfine hydrochloride in amorolfine liniment by HPLC.

Science.gov (United States)

Gao, Yuan; Li, Li; Zhang, Jianjun; Shu, Wenjuan; Gao, Liqiong

2012-04-01

A simple, rapid, specific and precise reversed-phase high-performance liquid chromatographic method was developed for simultaneous estimation of triacetin, acetic ether, butyl acetate and amorolfine in marketed pharmaceutical liniment. Chromatographic separation was performed on a Shimadzu VP-ODS C(18) column using the mixture of citric acid-hydrochloric acid-sodium hydrate buffer (pH 3.0), acetonitrile and methanol (32:30:38) as the mobile phase at a flow rate of 1.0 mL/min with UV-detection at 215 nm. The method separated the four components simultaneously in less than 10 min. The validation of the method was performed with respect to specificity, linearity, accuracy, and precision. The calibration curves were linear in the range of 35.1-81.9 μ/mL for triacetin, 431.1-1005.9 μ/mL for acetic ether, 167.0-389.7 μ/mL for butyl acetate and 151.0-352.3 μ/mL for amorolfine. The mean 100% spiked recovery for triacetin, acetic ether, butyl acetate and amorolfine is 99.43 ± 0.42, 101.5 ± 1.09, 101.4 ± 1.02 and 100.8 ± 0.69, respectively. The intra-day and inter-day relative standard deviation values were liniment.

Reverse isotope dilution method for determining benzene and metabolites in tissues

International Nuclear Information System (INIS)

Bechtold, W.E.; Sabourin, P.J.; Henderson, R.F.

1988-01-01

A method utilizing reverse isotope dilution for the analysis of benzene and its organic soluble metabolites in tissues of rats and mice is presented. Tissues from rats and mice that had been exposed to radiolabeled benzene were extracted with ethyl acetate containing known, excess quantities of unlabeled benzene and metabolites. Butylated hydroxytoluene was added as an antioxidant. The ethyl acetate extracts were analyzed with semipreparative reversed-phase HPLC. Isolated peaks were collected and analyzed for radioactivity (by liquid scintillation spectrometry) and for mass (by UV absorption). The total amount of each compound present was calculated from the mass dilution of the radiolabeled isotope. This method has the advantages of high sensitivity, because of the high specific activity of benzene, and relative stability of the analyses, because of the addition of large amounts of unlabeled carrier analogue

Antioxidant Efficacies of Rutin and Rutin Esters in Bulk Oil and Oil-in-Water Emulsion

DEFF Research Database (Denmark)

Lue, Bena-Marie; Sørensen, Ann-Dorit Moltke; Jacobsen, Charlotte

2017-01-01

concentrations (25 and 200 µM) was assessed in bulk oil and in an o/w emulsion system without and with iron addition. All evaluated compounds revealed antioxidant effects. However, rutin and BHT were the most efficient antioxidants in bulk oil followed by rutin palmitate, whereas rutin laurate acted as either......The use of flavonoids as antioxidants in food formulations is limited due to their solubility and thereby their localization in the food products. However, enzymatic alkylation of flavonoids with lipophilic moieties alters their lipophilicity and thereby partitioning within different phases...... in a food product. This study aimed to evaluate the antioxidative efficiency of two derivatives of rutin, namely rutin laurate (C12:0) and rutin palmitate (C16:0) compared with their parent compound rutin and with butylated hydroxytoluene (BHT). Their efficiency as antioxidants at two different...

Impact of endogenous canola phenolics on the oxidative stability of oil‐in‐water emulsions

DEFF Research Database (Denmark)

Sørensen, Ann-Dorit Moltke; Friel, James; Winkler‐Moser, Jill K.

2013-01-01

The aim of this study was to evaluate the antioxidative effect of phenolics naturally present in canola seeds and meal. Individual phenolics were extracted from ground, defatted canola seeds, and meal. Fractionated extracts rich in sinapic acid, sinapine, or canolol as well as a non......‐fractionated extract were used. These extracts (100 and 350 µM) were evaluated as antioxidants in stripped canola oil‐in‐water (o/w) emulsion. For comparison, the antioxidative effect of phenolic standards for sinapic acid and sinapine (as sinapine thiocyanate) and butylated hydroxytoluene (BTH) as a positive control....... Therefore, these canola extracts can be used for protecting canola oil emulsion or other emulsions against lipid oxidation. However, the results indicate that the antioxidant activity of the extracts rich in sinapine and canolol had a concentration‐sensitive effect. In order to get the best antioxidative...

Development and validation of RP-HPLC-UV/ Vis method for determination of phenolic compounds in several personal care products

International Nuclear Information System (INIS)

Mohammed Akkbik; Zaini Asim; Fasihuddin Ahmad

2011-01-01

A HPLC method with ultraviolet-visible spectrophotometry detection has been optimized and validated for the simultaneous determination of phenolic compounds, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as antioxidants, and octyl methyl cinnamate (OMC) as UVB-filter in several personal care products. The dynamic range was between 1 to 250 mg/ L with relative standard deviation less than 0.25 %, (n=4). Limit of detection for BHA, BHT and OMC were 0.196, 0.170 and 0.478 mg/ L, respectively. While limit of quantification for BHA, BHT and OMC were 0.593, 0.515 and 1.448 mg/ L, respectively. The recovery for BHA, BHT and OMC ranged from 92.1-105.9 %, 83.2-108.9 % and 87.3-103.7 %, respectively. The concentration ranges of BHA, BHT and OMC in 12 commercial personal care samples were 0.13-4.85, 0.16-2.30 and 0.12-65.5 mg/ g, respectively. The concentrations of phenolic compounds in these personal care samples were below than maximum allowable concentration in personal care formulation for example 0.0004 - 10 mg/ g, 0.002 - 5 mg/ g and up to 100 mg/ g for BHA, BHT and OMC, respectively. (author)

Gum cordia as carrier of antioxidants: effects on lipid oxidation of peanuts.

Science.gov (United States)

Haq, Muhammad Abdul; Azam, Mahmood; Hasnain, Abid

2015-04-01

Performance of antioxidants is improved by incorporating them into polymer matrix such as polysaccharides based edible coatings. Gum cordia, an anionic polysaccharide extracted from the fruits of Cordia.myxa could be used as carrier of antioxidants by virtue of its strong adhering and emulsifying properties. This study aimed to explore the potential of gum cordia as carrier of antioxidants when applied as edible coating on peanuts. Gum Cordia was compared with carboxymethyl cellulose (CMC) in delivering of antioxidants: butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and ascorbic acid (AA). Coated and uncoated peanuts were stored at 35 °C for 126 days and coating carrier effectiveness was measured by following lipid oxidation using chemical parameters (peroxide value and thiobarbituric acid reactive species) and sensory evaluation (oxidized flavor). Significant differences (p cordia was found better than CMC to deliver the antioxidants. Gum cordia based coating in combination with BHA/BHT exhibited highest protection (290 % higher shelf life than control) based on peroxide value (40 meq.O2 kg(-1)) followed by gum codia plus BHT (244 %), gum cordia plus BHA (232 %), CMC plus BHA/BHT (184 %), CMC plus BHA (139 %), CMC plus BHT (119 %), gum cordia plus AA (96 %) and CMC plus AA (46 %).

Chemical constituents and antioxidant activity of the essential oil from leaves of Annona vepretorum Mart. (Annonaceae).

Science.gov (United States)

Araújo, Camila de Souza; de Oliveira, Ana Paula; Lima, Rafaely Nascimento; Alves, Péricles Barreto; Diniz, Tâmara Coimbra; da Silva Almeida, Jackson Roberto Guedes

2015-01-01

Annona vepretorum (AV) is a native tree from Caatinga biome (semiarid region of Brazil) popularly known as "araticum" and "pinha da Caatinga." This study was carried out to evaluate the chemical constituents and antioxidant activity (AA) of the essential oil from the leaves from AV (EO-Av) collected in Petrolina, Pernambuco, Brazil. Fresh leaves of AV were cut into pieces, and subjected to distillation for 2 h in a clevenger-type apparatus. Gas chromatograph (GC) analyses were performed using a mass spectrometry/flame ionization detector. The identification of the constituents was assigned on the basis of comparison of their relative retention indices. The antioxidant ability of the EO was investigated through two in vitro models such as radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl method and β-carotene-linoleate-model system. The positive controls (ascorbic acid, butylated hydroxyanisole and butylated hydroxytoluene) were those using the standard solutions. Assays were carried out in triplicate. The oil showed a total of 21 components, and 17 were identified, representing 93.9% of the crude EO. Spathulenol (43.7%), limonene (20.5%), caryophyllene oxide (8.1%) and α-pinene (5.5%) were found to be the major individual constituents. Spathulenol and caryophyllene oxide could be considered chemotaxonomic markers of these genera. The EO demonstrated weak AA.

Occurrence and potential crop uptake of emerging contaminants and related compounds in an agricultural irrigation network

Energy Technology Data Exchange (ETDEWEB)

Calderon-Preciado, Diana [IDAEA-CSIC, Jordi Girona, 18, E-08034 Barcelona (Spain); Matamoros, Victor, E-mail: victor.matamoros@udg.edu [Department of Chemistry, University of Girona, Campus Montilivi, 17071 Girona (Spain); Bayona, Josep M. [IDAEA-CSIC, Jordi Girona, 18, E-08034 Barcelona (Spain)

2011-12-15

Emerging contaminants have received much attention in recent years due to their presence in surface waters, but little attention has been paid to their occurrence in agricultural irrigation waters. This study investigated the occurrence of these compounds in an agricultural irrigation network in northeastern Spain and, for the first time, using two plant uptake models, estimated the concentration of selected micropollutants in crops. The concentration of micropollutants in agricultural irrigation waters ranged from 10 to 5130 ng L{sup -1} and exhibited some attenuation over the course of the irrigation network. Bromoform, chloroform, diclofenac, caffeine, ibuprofen, naproxen, methyl dihydrojasmonate, galaxolide, butylated hydroxytoluene, and butylated hydroxyanisole were the most abundant contaminants (> 200 ng L{sup -1}, on average). The estimated concentration of micropollutants in crops ranged from < 1 to 7677 ng kg{sup -1}, with the neutral compounds being the most abundant. Moreover, the predicted data obtained by fate models generally agreed with experimental data. Finally, human exposure to micropollutants through fruit and vegetable consumption was estimated to be 9.8 {mu}g per person and week ({Sigma} 27 contaminants detected). Further studies are needed to determine the health implications that the presence of these compounds in fruit and vegetables may have for consumers.

Preparation and Properties of Triethoxyvinylsilane-Modified Styrene - Butyl Acrylate Emulsion Copolymers

OpenAIRE

NAGHASH, Hamid Javaherian; KARIMZADEH, Akram; MOMENI, Ahmad Reza; MASSAH, Ahmad Reza; ALIAN, Hamid

2014-01-01

The copolymers of triethoxyvinylsilane (TEVS) with styrene (St), butyl acrylate (BA), and methacrylic acid (MAA) were prepared by emulsion polymerization. The copolymerization was carried out by using auxiliary agents at 90 °C in the presence of potassium peroxodisulfate (KPS) as the initiator. Nonylphenol ethylene oxide -- 40 units (NP-40) and sodium lauryl sulfoacetate (SLSA) were used as nonionic and anionic emulsifiers, respectively. The resulting copolymers were characterized b...

Butylated hydroxyanisole induces distinct expression patterns of Nrf2 and detoxification enzymes in the liver and small intestine of C57BL/6 mice

Energy Technology Data Exchange (ETDEWEB)

Luo, Lin [Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Department of Pharmacology, University of Nantong, Nantong (China); Chen, Yeru; Wu, Deqi; Shou, Jiafeng [Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Wang, Shengcun [Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Ye, Jie [Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Tang, Xiuwen, E-mail: xiuwentang@zju.edu.cn [Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Wang, Xiu Jun, E-mail: xjwang@zju.edu.cn [Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058 (China)

2015-11-01

Butylated hydroxyanisole (BHA) is widely used as an antioxidant and preservative in food, food packaging and medicines. Its chemopreventive properties are attributing to its ability to activate the transcription factor NF-E2 p45-related factor 2 (Nrf2), which directs central genetic programs of detoxification and protection against oxidative stress. This study was to investigate the histological changes of Nrf2 and its regulated phase II enzymes Nqo1, AKR1B8, and Ho-1 in wild-type (WT) and Nrf2{sup −/−} mice induced by BHA. The mice were given a 200 mg/kg oral dose of BHA daily for three days. Immunohistochemistry revealed that, in the liver from WT mice, BHA increased Nqo1 staining in hepatocytes, predominately in the pericentral region. In contrast, the induction of AKR1B8 appeared mostly in hepatocytes in the periportal region. The basal and inducible Ho-1 was located almost exclusively in Kupffer cells. In the small intestine from WT mice, the inducible expression patterns of Nqo1 and AKR1B8 were nearly identical to that of Nrf2, with more intense staining in the villus than that the crypt. Conversely, Keap1 was more highly expressed in the crypt, where the proliferative cells reside. Our study demonstrates that BHA elicited differential expression patterns of phase II-detoxifying enzymes in the liver and small intestine from WT but not Nrf2{sup −/−} mice, demonstrating a cell type specific response to BHA in vivo. - Highlights: • Histological view of basal and inducible Nrf2 and its targets in vivo • Induction of detoxification enzymes by BHA is cell-type dependent. • BHA induces the expression of HO-1 in Kupffer cells.

DERMAL, ORAL AND INHALATION PHARMACOKINETICS OF METHYL TERTIARY-BUTYL ETHER (MTBE) IN HUMAN VOLUNTEERS

Science.gov (United States)

Methyl tertiary butyl ether (MTBE), a gasoline additive used to increase octane and reduce carbon monoxide emissions and ozone precursors, has contaminated drinking water and can lead to exposure by oral, inhalation, and dermal routes. To determine its dermal, oral, and inhal...

Bladder urotoxicity pathophysiology induced by the oxazaphosphorine alkylating agents and its chemoprevention 

Directory of Open Access Journals (Sweden)

Łukasz Dobrek

2012-09-01

Full Text Available The use of oxazaphosphorines (cyclophosphamide, ifosfamide in the treatment of numerous neoplastic disorders is associated with their essential adverse effect in the form of hemorrhagic cystitis, which considerably limits the safety and efficacy of their pharmacotherapy. HC is a complex inflammatory response, induced by toxic oxazaphosphorines metabolite – acrolein with subsequent immunocompetetive cells activation and release of many proinflammatory agents. However, there are some chemoprotectant agents which help reduce the HC exacerbation.The article briefly discuses the mechanism of action of oxazaphosphorines, the pathophysiology of the hemorrhagic cystitis development and currently accepted chemopreventive agents, applied to the objective of urotoxicity amelioration. Moreover, the rationale for some phytopharmaceuticals administration as novel bladder protective compounds accompanying cyclophosphamide or ifosfamide therapy was also mentioned. 

A new efficient synthesis of isothiocyanates from amines using di-tert-butyl dicarbonate

DEFF Research Database (Denmark)

Munch, Henrik; Hansen, Jon S.; Pittelkow, Michael

2008-01-01

Alkyl and aryl amines are converted smoothly to the corresponding isothiocyanates via the dithiocarbamates in good to excellent yields using di-tert-butyl dicarbonate (Boc(2)O) and 1-3 mol% of DMAP or DABCO as catalyst. As most of the byproducts are volatile, the work-up involves simple evaporation...

Glycerol tertiary butyl ethers via etherification of glycerol with isobutene

Energy Technology Data Exchange (ETDEWEB)

Behr, A. [Dortmund Univ. (Germany). Chair of Chemical Process Development/Technical Chemistry A

2007-07-01

Glycerol and isobutene can react to a mixture of glycerol tertiary butyl ethers (GTBE) which can be used as additives for gasoline, diesel or biodiesel. This reaction was investigated in lab scale yielding a proposal for a process flow diagram containing reaction, extraction, flash and rectification units. This process has the advantages that only the suitable higher ethers are formed and that both glycerol and isobutene are fully converted. The homogeneous acid catalyst is low-priced and can be completely recycled. (orig.)

n-Alkane assimilation and tert-butyl alcohol (TBA) oxidation capacity in Mycobacterium austroafricanum strains.

Science.gov (United States)

Lopes Ferreira, Nicolas; Mathis, Hugues; Labbé, Diane; Monot, Frédéric; Greer, Charles W; Fayolle-Guichard, Françoise

2007-06-01

Mycobacterium austroafricanum IFP 2012, which grows on methyl tert-butyl ether (MTBE) and on tert-butyl alcohol (TBA), the main intermediate of MTBE degradation, also grows on a broad range of n-alkanes (C2 to C16). A single alkB gene copy, encoding a non-heme alkane monooxygenase, was partially amplified from the genome of this bacterium. Its expression was induced after growth on n-propane, n-hexane, n-hexadecane and on TBA but not after growth on LB. The capacity of other fast-growing mycobacteria to grow on n-alkanes (C1 to C16) and to degrade TBA after growth on n-alkanes was compared to that of M. austroafricanum IFP 2012. We studied M. austroafricanum IFP 2012 and IFP 2015 able to grow on MTBE, M. austroafricanum IFP 2173 able to grow on isooctane, Mycobacterium sp. IFP 2009 able to grow on ethyl tert-butyl ether (ETBE), M. vaccae JOB5 (M. austroaafricanum ATCC 29678) able to degrade MTBE and TBA and M. smegmatis mc2 155 with no known degradation capacity towards fuel oxygenates. The M. austroafricanum strains grew on a broad range of n-alkanes and three were able to degrade TBA after growth on propane, hexane and hexadecane. An alkB gene was partially amplified from the genome of all mycobacteria and a sequence comparison demonstrated a close relationship among the M. austroafricanum strains. This is the first report suggesting the involvement of an alkane hydroxylase in TBA oxidation, a key step during MTBE metabolism.

(R-N-{2-tert-Butyl-2-[(R-tert-butylsulfonamido]ethylidene}-tert-butanesulfonamide

Directory of Open Access Journals (Sweden)

Cong-Bin Fan

2008-10-01

Full Text Available The title compound, C14H30N2O2S2, is the product of the monoaddition reaction of tert-butyl magnesium chloride with bis-[(R-N-tert-butanesulfinyl]ethanediimine. There are two almost identical molecules in the asymmetric unit, the molecular conformation of which is stabilized by an intramolecular N—H...N hydrogen bond.

Emulsion (Co)polymerization of styrene and butyl acrylate monitored by On-line Raman Spectroscopy

NARCIS (Netherlands)

van den Brink, H.J.T.; Pepers, M.L.H.; Herk, van A.M.; German, A.L.

2000-01-01

The homo- and copolymerizations of styrene and n-butyl acrylate were studied by on-line in-situ Raman spectroscopy.Results from the solution (homo)polymerizations proved to be very useful in the quantification of the Raman data from the emulsion homopolymerization. From the homopolymerization data

Continuous ARGET ATPR of methyl methacrylate and butyl acrylate in a stirred tank reactor

NARCIS (Netherlands)

Chan, N.; Meuldijk, J.; Cunningham, M.F.; Hutchinson, R.A.

2013-01-01

ARGET ATRP (activator regenerated by electron transfer atom transfer radical polymerization) of butyl acrylate (BA) and methyl methacrylate (MMA) was successfully adapted from a batch process to a continuous stirred tank reactor (CSTR) with 50 ppm copper. A series of batch polymerizations were first

Time-Resolved WAXD and SAXS Investigations on Butyl Branched Alkane at Elevated Pressures

NARCIS (Netherlands)

Rastogi, A.; Hobbs, J.K.; Rastogi, S.

2002-01-01

The crystallization behavior and the morphological aspect of the butyl branched alkane C96H193CH(C4H9)C94H189 have been investigated using time-resolved wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) at atmospheric and elevated pressures. The solution crystallized sample

Synthesis of 2,6-diisopropyl-phenylcarbamoylmethyl-iminodiacetic acid (DISIDA) and 4-n-p-butyl-phenylcarbamoylmethyl-iminodiacetic acid (BUTYL-IDA). Preparation of lyophilized kit to be used as 99(supm)Tc agent in hepatobiliary system

International Nuclear Information System (INIS)

Hamada, E.S.; Barbosa, M.F. de; Theodora, M.A.; Almeida, M. de; Colturato, M.T.; Muramoto, E.; Silva, C.P.G. da.

1987-08-01

The synthesis of 2,6 diisopropyl IDA (DISIDA) and 4-n-butyl IDA (BUTIL-IDA) is described. Their spectroscopic properties, radiopharmaceutical preparation and their use as 99 (sup m)Tc complex agent in hepatobiliary studies, are also reported. (Author) [pt

The Emulsion Polymerization of Each of Vinyl Acetate and Butyl Acrylate Monomers Using bis (2-ethylhexyl) Maleate for Improving the Physicomechanical Properties of Paints and Adhesive Films

International Nuclear Information System (INIS)

Shaffei, K.A.; Moustafa, A.B.; Hamed, A.I.

2009-01-01

Improving the water sensitivity of polyvinyl acetate PVAc films as well as pressure sensitivity, adhesion and washability of poly butyl acrylate were achieved by using bis (2-ethylhexyl) maleate (BEHM). The emulsion polymerization kinetics of vinyl acetate and butyl acrylate in presence of BEHM was studied. The order of the polymerization reaction with respect to the BEHM in presence of each of vinyl acetate and butyl acrylate was studied. The physicomechanical properties of the polyvinyl acetate films and vinyl acetate-butyl acrylate copolymer films were studied in presence of BEHM and the obtained results were matched with those prepared in the presence of pluronic F 108 and showed superior values. The obtained mean average molecular weights were found to be smaller in presence of BEHM assuring the presence of chain transfer reaction.

t-Butyl group-substituted triphenylamine-containing orange-red fluorescent emitters for organic light-emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Lee, Kum Hee; Kim, Chi Sik [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@hongik.ac.kr [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of)

2012-03-30

Efficient orange-red fluorescent compounds, 4-(dicyanomethylene)-2-adamantyl-6-(4-(N-(4-tert-butylphenyl) -N-(3,5-di-tert-butylphenyl)amino)benzene)vinyl-4H-pyran (DCATP) and 2,6-bis[4-(N-(4-tert-butylphenyl)-N-(3,5-di-tert-butylphenyl)amino)benzene] vinyl-4-(dicyanomethylene)-4H-pyran (BDCTP) containing the tert-butylated triphenylamine in donor moieties, were synthesized and characterized. In these red emitters, bulky groups, such as t-butyl group and adamantane were introduced to increase the steric hindrance between the red emitters. In particular, an efficient orange-red device containing the emitter DCATP as a dopant showed a luminous and power efficiency of 6.87 cd/A and 2.70 lm/W, respectively, at 20 mA/cm{sup 2} with the CIE coordinates of (0.48, 0.50) at 7.0 V. In addition, an efficient red organic light-emitting diode using BDCTP as a dopant exhibited a luminous and power efficiency of 2.30 cd/A and 1.31 lm/W, respectively, at 20 mA/cm{sup 2} and CIE coordinates of (0.61, 0.39). - Highlights: Black-Right-Pointing-Pointer Two orange-red emitters with t-butylated triphenylamine derivatives were studied. Black-Right-Pointing-Pointer We examine changes in electron D-A and electron D-A-D type in the terminal groups. Black-Right-Pointing-Pointer Electron D-A-D type material shows improved color chromaticity.

Di-tert-butyl-chlorido(N,N-dibenzyl-dithio-carbamato)tin(IV).

Science.gov (United States)

Abdul Muthalib, Amirah Faizah; Baba, Ibrahim; Mohamed Tahir, Mohamed Ibrahim; Tiekink, Edward R T

2011-02-26

The Sn(IV) atom in the title diorganotin dithio-carbamate, [Sn(C(4)H(9))(2)(C(15)H(14)NS(2))Cl], is penta-coordinated by an asymmetrically coordinating dithio-carbamate ligand, a Cl atom and two C atoms of the Sn-bound tert-butyl groups. The resulting C(2)ClS(2) donor set defines a coordination geometry inter-mediate between square pyramidal and trigonal bipyramidal with a slight tendency towards the former.

Adlay (薏苡 yì yĭ; “soft-shelled job's tears”; the seeds of Coix lachryma-jobi L. var. ma-yuen Stapf is a Potential Cancer Chemopreventive Agent toward Multistage Carcinogenesis Processes

Directory of Open Access Journals (Sweden)

Ching-Chuan Kuo, Ph.D.

2012-10-01

Full Text Available Adlay (薏苡 yì yĭ; “soft-shelled job’s tears”, the seeds of Coix lachryma-jobi L. var. ma-yuen Stapf is a grass crop that has long been used in traditional Chinese medicine (TCM and as a nourishing food in China for the treatment of warts, chapped skin, rheumatism, neuralgia, inflammatory, and neoplastic diseases. In addition, adlay also has been said to have stomachic, diuretic, antipholgistic, anodynic, and antispasmodic effects. Carcinogenesis is a multistage process that begins with exposure of viruses or chemicals that are found in the environment. Chemoprevention refers to the use of natural or synthetic, non-toxic chemical substances to reverse, repress, or prevent carcinogenesis. In this review, we summarize recent research attempting to study the chemopreventive blocking and suppressing potential of adlay and its active components in scavenging electrophiles and reactive oxygen species, antimutagenicity, enhancing Nrf2-mediated detoxification and antioxidant effect, altering carcinogen metabolism, suppressing proliferation, decreasing inflammation, and enhancing antitumor immunity. In addition, several active components with diverse chemopreventive properties have been also mentioned in this review article.

Phase equilibrium conditions of semi-calthrate hydrates of (tetra-n-butyl ammonium chloride + carbon dioxide)

International Nuclear Information System (INIS)

Sun, Zhi-Gao; Jiao, Li-Jun; Zhao, Zhi-Gui; Wang, Gong-Liang; Huang, Hai-Feng

2014-01-01

Highlights: • Carbon dioxide hydrate stability zone was enlarged with the help of TBAC. • Carbon dioxide uptake into TBAC semi-clathrate hydrates is confirmed. • Equilibrium pressure of hydrate decreased with the increase of TBAC mass concentration. • The addition of TBAC reduces the formation pressures of carbon dioxide hydrate by 2.5 MPa. - Abstract: In the present work, hydrate equilibrium conditions for (tetra-n-butyl ammonium chloride (TBAC) + carbon dioxide + water) mixtures were investigated. Tetra-n-butyl ammonium chloride was reported to form a semi-clathrate hydrate. The experiments were carried out within the TBAC mass fraction range of (0.05 to 0.3). The experimental results showed that the presence of TBAC decreased the formation pressure of carbon dioxide double hydrate within the experimental temperature range. Moreover, pressure reduction was dependent on the TBAC concentration

Nitrates and NO-NSAIDs in Cancer Chemoprevention & Therapy: In Vitro Evidence Querying the NO Donor Functionality

Science.gov (United States)

Dunlap, Tareisha; Abdul-Hay, Samer; Chandrasena, R. Esala P.; Hagos, Ghenet K; Sinha, Vaishali; Wang, Zhiqiang; Wang, Huali; Thatcher, Gregory R. J.

2008-01-01

Properties of the NO-ASA family of NO-donating NSAIDs (NO-NSAIDs), notably NCX 4016 (mNO-ASA) and NCX 4040 (pNO-ASA), reported in more than a hundred publications, have included positive preclinical data in cancer chemoprevention and therapy. Evidence is presented that the antiproliferative, the chemopreventive (antioxidant/electrophile response element (ARE) activation), and the anti-inflammatory activity of NO-ASA in cell cultures is replicated by X-ASA derivatives that are incapable of acting as NO donors. pBr-ASA and mBr-ASA are conisogenic with NO-ASA, but are not NO donors. The biological activity of pNO-ASA is replicated by pBr-ASA; and both pNO-ASA and pBr-ASA are bioactivated to the same quinone methide electrophile. The biological activity of mNO-ASA is replicated by mBr-ASA; mNO-ASA and mBr-ASA are bioactivated to different benzyl electrophiles. The observed activity is likely initiated by trapping of thiol biomolecules by the quinone and benzyl electrophiles, leading to depletion of GSH and modification of Cys-containing sensor proteins. Whereas all NO-NSAIDs containing the same structural “linker” as NCX 4040 and NCX 4016 are anticipated to possess activity resulting from bioactivation to electrophilic metabolites, this expectation does not extend to other linker structures. Nitrates require metabolic bioactivation to liberate NO bioactivity, which is often poorly replicated in vitro, and NO bioactivity provided by NO-NSAIDs in vivo provides proven therapeutic benefits in mitigation of NSAID gastrotoxicity. The in vivo properties of X-ASA drugs await discovery. PMID:18485921

Chemopreventive effect and angiogenic activity of punicalagin isolated from leaves of Lafoensia pacari A. St.-Hil

Energy Technology Data Exchange (ETDEWEB)

Costa Carneiro, Cristiene, E-mail: profacristiene@gmail.com [Instituto de Ciências Biológicas, Universidade Federal de Goiás, 74001970 Goiânia, GO (Brazil); Costa Santos, Suzana da [Instituto de Química, Universidade Federal de Goiás, 74001970 Goiânia, GO (Brazil); Souza Lino, Ruy de [Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, 74605050 Goiânia, GO (Brazil); Bara, Maria Teresa Freitas; Chaibub, Beatriz Abdallah [Faculdade de Farmácia, Universidade Federal de Goiás, 74605170 Goiânia, GO (Brazil); Melo Reis, Paulo Roberto de; Chaves, Dwight Assis [Laboratório de Estudos Experimentais e Biotecnológicos, Pontifícia Universidade Católica de Goiás, 74605010 Goiânia, GO (Brazil); Ribeiro da Silva, Antônio Jorge [Núcleo de Pesquisas de Produtos Naturais, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, 21941590 Rio de Janeiro, RJ (Brazil); Santos Silva, Luana; Melo e Silva, Daniela de; Chen-Chen, Lee [Instituto de Ciências Biológicas, Universidade Federal de Goiás, 74001970 Goiânia, GO (Brazil)

2016-11-01

Punicalagin is the major ellagitannin constituent from leaves of Lafoensia pacari, a Brazilian medicinal plant widely used for the treatment of peptic ulcer and wound healing. Genotoxic, cytotoxic, antigenotoxic, and anticytotoxic effects of punicalagin were assessed using micronucleus (MN) test and comet assay in mice. Due to the extensive use of L. pacari in the wound healing process, we also assessed the angiogenic activity of punicalagin using the chick chorioallantoic membrane (CAM) angiogenic assay. The highest dose of punicalagin (50 mg/kg) showed significant cytotoxic effect by MN test and in the co-treatment with cyclophosphamide (CPA), this cytotoxicity was enhanced. Co-treatment, pre-treatment and post-treatment of punicalagin with CPA led to a significant reduction in the number of DNA breaks and in the frequency of CPA-induced MN, indicating antigenotoxic effect. Using the CAM model, punicalagin exhibited angiogenic activity in all doses mainly at the lowest concentration (12.5 μg/μL). Therefore, these findings indicate an effective chemopreventive role of punicalagin and a high capacity to induce DNA repair. Also, the angiogenic activity presented by punicalagin in this study could contribute for the processes of tissue repairing and wound healing. - Highlights: • The ellagitannin punicalagin was isolated for the first time from L. pacari leaves. • The genotoxic and chemopreventive effects of punicalagin were evaluated in mice. • The highest dose of punicalagin showed significant cytotoxic effect. • Punicalagin exhibited antigenotoxic effects by the co-, pre- and post-treatment. • Punicalagin showed angiogenic activity and could be applied for tissue repairing.

Clinical cancer chemoprevention: From the hepatitis B virus (HBV vaccine to the human papillomavirus (HPV vaccine

Directory of Open Access Journals (Sweden)

Horng-Jyh Tsai

2015-04-01

Full Text Available Approximately 2 million new cancer cases are attributed to infectious agents each year worldwide. Vaccines for the hepatitis B virus (HBV, a risk factor of hepatocellular cancer, and human papillomavirus (HPV, a risk factor of cervical cancer, are considered major successes in clinical chemoprevention of cancer. In Taiwan, the first evidence of cancer prevention through vaccinations was provided by HBV vaccination data in infants. The Taiwanese HBV vaccination program has since become a model immunization schedule for newborns worldwide. Persistent infection with high-risk HPV is generally accepted as prerequisite for cervical cancer diagnosis; however, cervical cancer is a rare complication of HPV infections. This is due to the fact that such infections tend to be transient. The safety and efficacy of both available HPV quadrivalent vaccine and bivalent vaccine are not in doubt at the present time. Until a human cytomegalovirus (CMV vaccine becomes available, simple hygienic practices, such as hand washing, can prevent CMV infection both before and during pregnancy. Each country should establish her official guidelines regarding which vaccines should be used to treat various conditions, the target population (i.e., universal or limited to a selected population, and the immunization schedules. After a vaccine is recommended, decisions regarding reimbursement by the public health care fund are evaluated. The guidelines become part of the immunization schedule, which is updated annually and published in the official bulletin. In conclusion, both HBV and HPV vaccines are considered major successes in the chemoprevention of cancer.

The effect of reducing monosaccharides on the atom transfer radical polymerization of butyl methacrylate

NARCIS (Netherlands)

Vries, de Andrew; Klumperman, B.; Wet-Roos, de D.; Sanderson, R.D.

2001-01-01

The effect of various reducing monosaccharides on the rate of atom transfer radical polymerization (ATRP) of butyl methacrylate is reported in this study. The addition of reducing sugars affects the rate of ATRP positively with a 100% increase in the rate of polymerization in some cases. In

Crystal structure of 2-tert-butyl-1,3-thiazolo[4,5-b]pyridine

Directory of Open Access Journals (Sweden)

Gamal A. El-Hiti

2014-09-01

Full Text Available The title compound, C10H12N2S, does not contain any strong hydrogen-bond donors but two long C—H...N contacts are observed in the crystal structure, with the most linear interaction linking molecules along [010]. The ellipsoids of the tert-butyl group indicate large librational motion.

Cancer Chemoprevention by Resveratrol: The p53 Tumor Suppressor Protein as a Promising Molecular Target

Directory of Open Access Journals (Sweden)

Danielly C. Ferraz da Costa

2017-06-01

Full Text Available Increasing epidemiological and experimental evidence has demonstrated an inverse relationship between the consumption of plant foods and the incidence of chronic diseases, including cancer. Microcomponents that are naturally present in such foods, especially polyphenols, are responsible for the benefits to human health. Resveratrol is a diet-derived cancer chemopreventive agent with high therapeutic potential, as demonstrated by different authors. The aim of this review is to collect and present recent evidence from the literature regarding resveratrol and its effects on cancer prevention, molecular signaling (especially regarding the involvement of p53 protein, and therapeutic perspectives with an emphasis on clinical trial results to date.

Sutureless vascular anastomoses by N-butyl-2 cyanoacrylate adhesive: an experimental animal study.

Science.gov (United States)

Saba, D; Yilmaz, M; Yavuz, H; Noyan, S; Avci, B; Ercan, A; Ozkan, H; Cengiz, M

2007-01-01

The purpose of this animal study was to find out whether sutureless anastomoses using N-butyl-2-cyanoacrylate were effective in the suppression of neointimal hyperplasia or not. Ten male adult mongrel dogs were used in this animal study. The animals were randomly divided into a control group (n = 5) and a study group (n = 5). The study group underwent sutureless anastomoses using N-buthyl-2-cyanoacrylate adhesive. Infrarenal aortoaortic graft was interposed using polytetrafluoroethylene. In the study group, the mean intimal thickness at the proximal anastomosis was 27.4 +/- 1.94 microm and 27.4 +/- 1.51 microm at the distal anastomosis. In the control group, the mean intimal thickness was 138.4 +/- 5.02 mum at the proximal anastomosis and 67.6 +/- 6.42 microm at the distal anastomosis. Intimal thickness at the proximal and distal anastomoses in the control group was significantly (p anastomoses using with N-butyl-2-cyanoacrylate adhesive might be a good alternative to conventional suture technique. Copyright 2007 S. Karger AG, Basel.

Mono- and di-n-butyl phosphates of some metals in spent nuclear fuel reprocessing

Energy Technology Data Exchange (ETDEWEB)

Solovkin, A.S.

1982-01-01

Results of investigations which have been carried out in the Soviet Union for the last 10 years on the determination of the composition, structure, conditions of the formation and solubility of mono- and di-n-butyl phosphates of metals (U/sup 6 +/, Pu/sup 4 +/, Pu/sup 3 +/, Th, Zr, Fe/sup 3 +/, Am, Al, rare-earth elements), which are important for the processes of irradiated nuclear fuel reprocessing, are presented. A conclusion is made that zirconium mono- and di-n-butyl phosphates are the least soluble in aqueous and organic solvents of all investigated compounds. FeA/sub 3/ and AmA/sub 3/ are weakly soluble in aqueous solutions. The other compounds are sufficiently soluble in moderately acidic aqueous solutions or in DBP and TBP with dilutents. The obtained results indicate at the similarity of zirconium and plutonium (4) chemical properties; thorium, in this respect, is not an analogue of plutonium (4). Possible structural formulas of the investigated compounds are considered.

Use of experimental design for the purge-and-trap-gas chromatography-mass spectrometry determination of methyl tert.-butyl ether, tert.-butyl alcohol and BTEX in groundwater at trace level.

Science.gov (United States)

Bianchi, F; Careri, M; Marengo, E; Musci, M

2002-10-25

An efficient method for the simultaneous determination of methyl tert.-butyl ether, tert.-butyl alcohol, benzene, toluene, ethylbenzene and xylene isomers in groundwater by purge-and-trap-gas chromatography-mass spectrometry was developed and validated. Experimental design was used to investigate the effects of temperature of extraction, time of extraction and percentage of salt added to the water samples. Regression models and desirability functions were applied to find the experimental conditions providing the highest global extraction yield. Validation was carried out in terms of limits of detection (LOD), limits of quantitation (LOQ), linearity and precision. LOD values ranging from 2.6 to 23 ng l(-1) were achieved, whereas linearity was statistically verified over two orders of magnitude for each compound. Precision was evaluated testing two concentration levels. Good results were obtained both in terms of intra-day repeatability and intermediate precision: RSD% lower than 4.5% at the highest concentration and lower than 13% at the lowest one were calculated for intra-day repeatability. A groundwater sample suspected of contamination by leaking underground petroleum storage tanks was analysed and some of the analytes were detected and quantitated.

Identification of volatile butyl rubber thermal-oxidative degradation products by cryofocusing gas chromatography/mass spectrometry (cryo-GC/MS).

Energy Technology Data Exchange (ETDEWEB)

Smith, Jonell Nicole; White, Michael Irvin; Bernstein, Robert; Hochrein, James Michael

2013-02-01

Chemical structure and physical properties of materials, such as polymers, can be altered as aging progresses, which may result in a material that is ineffective for its envisioned intent. Butyl rubber formulations, starting material, and additives were aged under thermal-oxidative conditions for up to 413 total days at up to 124 ÀC. Samples included: two formulations developed at Kansas City Plant (KCP) (#6 and #10), one commercially available formulation (#21), Laxness bromobutyl 2030 starting material, and two additives (polyethylene AC-617 and Vanax MBM). The low-molecular weight volatile thermal-oxidative degradation products that collected in the headspace over the samples were preconcentrated, separated, and detected using cryofocusing gas chromatography mass spectrometry (cryo-GC/MS). The majority of identified degradation species were alkanes, alkenes, alcohols, ketones, and aldehydes. Observations for Butyl #10 aged in an oxygen-18 enriched atmosphere (18O2) were used to verify when the source of oxygen in the applicable degradation products was from the gaseous environment rather than the polymeric mixture. For comparison purposes, Butyl #10 was also aged under non-oxidative thermal conditions using an argon atmosphere.

NOSH-aspirin (NBS-1120), a novel nitric oxide- and hydrogen sulfide-releasing hybrid has enhanced chemo-preventive properties compared to aspirin, is gastrointestinal safe with all the classic therapeutic indications

Science.gov (United States)

Kodela, Ravinder; Chattopadhyay, Mitali; Velázquez-Martínez, Carlos A.; Kashfi, Khosrow

2015-01-01

Aspirin is chemopreventive; however, side effects preclude its long-term use. NOSH-aspirin (NBS-1120), a novel hybrid that releases nitric oxide and hydrogen sulfide, was designed to be a safer alternative. Here we compare the gastrointestinal safety, anti-inflammatory, analgesic, antipyretic, anti-platelet, and chemopreventive properties of aspirin and NBS-1120 administered orally to rats at equimolar doses. Gastrointestinal safety: 6h post-administration, the number and size of hemorrhagic lesions in stomachs were counted; tissue samples were frozen for PGE2, SOD, and MDA determination. Anti-inflammatory: 1h after drug administration, the volume of carrageenan-induced rat paw edemas was measured for 5h. Anti-pyretic: fever was induced by LPS (ip) an hour before administration of the test drugs, core body temperature was measured hourly for 5h. Analgesic: time-dependent analgesic effects were evaluated by carrageenan-induced hyperalgesia. Antiplatelet: anti-aggregatory effects were studied on collagen-induced platelet aggregation of human platelet-rich plasma. Chemoprevention: Nude mice were gavaged daily for 25 days with vehicle, aspirin or NBS-1120. After one week, each mouse was inoculated subcutaneously in the right flank with HT-29 human colon cancer cells. Both agents reduced PGE2 levels in stomach tissue; however, NBS-1120 did not cause any stomach ulcers, whereas aspirin caused significant bleeding. Lipid peroxidation induced by aspirin was higher than that exerted by NBS-1120. SOD activity was significantly inhibited by aspirin but increased by NBS-1120. Both agents showed similar anti-inflammatory, analgesic, anti-pyretic, and anti-platelet activities. Aspirin increased plasma TNFα more than NBS-1120-treated animals. NBS-1120 was better than aspirin as a chemopreventive agent; it dose-dependently inhibited tumor growth and tumor mass. PMID:26394025

Di-tert-butyl 2,2′-[(biphenyl-4,4′-diyldioxy]diacetate

Directory of Open Access Journals (Sweden)

Qamar Ali

2010-07-01

Full Text Available The complete molecule of the title compound, C24H30O6, is generated by a crystallographic inversion centre. In the unique part of the molecule, the four-atom –O–CH2–C(= O–O– chain between the benzene ring and the tert-butyl group assumes a zigzag conformation [O—C—C—O torsion angle = −162.3 (1°].

Critically evaluated rate coefficients for free-radical polymerization, 5. Propagation rate coefficient for butyl acrylate

NARCIS (Netherlands)

Asua, J.M.; Beuermann, S.; Buback, M.; Castignolles, P.; Charleux, B.; Gilbert, R.G.; Hutchinson, R.A.; Leiza, J.R.; Nikitin, A.N.; Vairon, J.P.; Herk, van A.M.

2004-01-01

Propagation rate coefficients, kp, for free-radical polymerization of butyl acrylate (BA) previously reported by several groups are critically evaluated. All data were determined by the combination of pulsed-laser polymerization (PLP) and subsequent polymer analysis by size exclusion (SEC)

Risicogrenzen voor MTBE (Methyl tertiair-Butyl Ether) in bodem, sediment, grondwater, oppervlaktewater en voor drinkwaterbereiding

NARCIS (Netherlands)

Swartjes FA; Baars AJ; Fleuren RHLJ; Otte PF; LER

2004-01-01

Recentelijk is politieke commotie ontstaan ten gevolge van de mogelijke schadelijke gezondheidseffecten van Methyl tertiair-Butyl Ether (MTBE). Dit was reden voor het ministerie van VROM om het RIVM te verzoeken risicogrenzen voor MTBE in bodem, sediment, grondwater, oppervlaktewater, drinkwater en

Forensic analysis of tertiary-butyl alcohol (TBA) detections in a hydrocarbon-rich groundwater basin.

Science.gov (United States)

Quast, Konrad W; Levine, Audrey D; Kester, Janet E; Fordham, Carolyn L

2016-04-01

Tertiary-butyl alcohol (TBA), a high-production volume (HPV) chemical, was sporadically detected in groundwater and coalbed methane (CBM) wells in southeastern Colorado's hydrocarbon-rich Raton Basin. TBA concentrations in shallow water wells averaged 75.1 μg/L, while detections in deeper CBM wells averaged 14.4 μg/L. The detection of TBA prompted a forensic investigation to try to identify potential sources. Historic and recent data were reviewed to determine if there was a discernable pattern of TBA occurrence. Supplemental samples from domestic water wells, monitor wells, CBM wells, surface waters, and hydraulic fracturing (HF) fluids were analyzed for TBA in conjunction with methyl tertiary-butyl ether (MTBE) and ethyl tertiary-butyl ether (ETBE), proxies for evidence of contamination from reformulated gasoline or associated oxygenates. Exploratory microbiological sampling was conducted to determine if methanotrophic organisms co-occurred with TBA in individual wells. Meaningful comparisons of historic TBA data were limited due to widely varying reporting limits. Mapping of TBA occurrence did not reveal any spatial patterns or physical associations with CBM operations or contamination plumes. Additionally, TBA was not detected in HF fluids or surface water samples. Given the widespread use of TBA in industrial and consumer products, including water well completion materials, it is likely that multiple diffuse sources exist. Exploratory data on stable isotopes, dissolved gases, and microbial profiling provide preliminary evidence that methanotrophic activity may be producing TBA from naturally occurring isobutane. Reported TBA concentrations were significantly below a conservative risk-based drinking water screening level of 8000 μg/L derived from animal toxicity data.

Moessbauer spectroscopic characterisation of catalysts obtained by interaction between tetra-n-butyl-tin and silica or silica supported rhodium

International Nuclear Information System (INIS)

Millet, J.M.M.; Toyir, J.; Didillon, B.; Candy, J.P.; Nedez, C.; Basset, J.M.

1997-01-01

Moessbauer spectroscopy at 78 K was used to study the interaction between tetra-n-butyl-tin and the surfaces of silica or silica supported rhodium. At room temperature, the tetra-n-butyl-tin was physically adsorbed on the surfaces. After reaction under hydrogen at 373 K, the formation of grafted organometallic fragments on the Rh surface was confirmed whereas with pure silica, ≡SiO-Sn(n-C 4 H 9 ) 3 moieties were observed. After treatment at 523 K, the rhodium grafted organometallic species was completely decomposed and there was formation of a defined bimetallic RhSn compound

Study on separation of methanol-butyl methylether-1-chlorobutane system

International Nuclear Information System (INIS)

Zhang Weijiang; Cao Tianhong

2006-01-01

The separation of mixture plays an important role in chemical, petrochemical, medical biochemical industries and environmental protection engineering. Liquid mixture with azeotropic phenomenon cannot be separated by conventional distillation as well as extractive distillation. But the combination of extraction and distillation can be effective for them. This paper includes many experiments with the ternary mixture of methanol butyl methyl ether and 1-chlorobytane, which shows that the system is not ternary azeotrope and can be separated by the combination of extraction and rectification using water as extractive solvent. (authors)

The gaseous enthalpy of formation of the ionic liquid 1-butyl-3-methylimidazolium dicyanamide from combustion calorimetry, vapor pressure measurements, and ab initio calculations.

Science.gov (United States)

Emel'yanenko, Vladimir N; Verevkin, Sergey P; Heintz, Andreas

2007-04-04

Ionic liquids are attracting growing interest as alternatives to conventional molecular solvents. Experimental values of vapor pressure, enthalpy of vaporization, and enthalpy of formation of ionic liquids are the key thermodynamic quantities, which are required for the validation and development of the molecular modeling and ab initio methods toward this new class of solvents. In this work, the molar enthalpy of formation of the liquid 1-butyl-3-methylimidazolium dicyanamide, 206.2 +/- 2.5 kJ.mol-1, was measured by means of combustion calorimetry. The molar enthalpy of vaporization of 1-butyl-3-methylimidazolium dicyanamide, 157.2 +/- 1.1 kJ.mol-1, was obtained from the temperature dependence of the vapor pressure measured using the transpiration method. The latter method has been checked with measurements of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, where data are available from the effusion technique. The first experimental determination of the gaseous enthalpy of formation of the ionic liquid 1-butyl-3-methylimidazolium dicyanamide, 363.4 +/- 2.7 kJ.mol-1, from thermochemical measurements (combustion and transpiration) is presented. Ab initio calculations of the enthalpy of formation in the gaseous phase have been performed for 1-butyl-3-methylimidazolium dicyanamide using the G3MP2 theory. Excellent agreement with experimental results has been observed. The method developed opens a new way to obtain thermodynamic properties of ionic liquids which have not been available so far.

MONITORED NATURAL ATTENUATION OF TERTIARY BUTYL ALCOHOL (TBA) IN GROUND WATER AT GASOLINE SPILL SITES

Science.gov (United States)

The state agencies that implement the Underground Storage Tank program rely heavily on Monitored Natural Attenuation (MNA) to clean up contaminants such as benzene and methyl tertiary butyl ether (MTBE) at gasoline spill sites. This is possible because the contaminants are biolo...

Densities and Kinematic Viscosities for the Systems Benzene + Methyl Formate, Benzene + Ethyl Formate, Benzene + Propyl Formate, and Benzene + Butyl Formate

DEFF Research Database (Denmark)

Emmerling, Uwe; Rasmussen, Peter

1998-01-01

a Redlich-Kister type of expression with temperature-independent parameters and the data for the systems benzene + ethyl formate, benzene + propyl formate, and benzene + butyl formate with temperature-dependent parameters. The viscosities have furthermore been compared to values predicted by means of the GC......Densities and kinematic viscosities have been measured for the system benzene + methyl formate at 20°C and for the systems benzene + ethyl formate, benzene + propyl formate, and benzene + butyl formate from 20°C to 50°C. The results for the system benzene + methyl formate have been correlated using...

Influence of Emulsion Polymerization Techniques to Particle Size of Copoly(styrene/butyl acrylate/methyl methacrylate

Directory of Open Access Journals (Sweden)

Tresye Utari

2008-04-01

Full Text Available In the majority of applications, particle size and particle size distribution are highly significant factors that determine the properties of a polymer dispersion, such as its flow behavior or its stability. For example, a coating material with small particle size will give smooth coating result, good adhesive strength, good water resistance and latex stability. This article describes influence of various emulsion polymerization techniques to particle size of copoly(styrene/butyl acrylate/methyl methacrylate with mix surfactant SDBS linear chain and nonyl fenol (EO10 and initiator ammonium persulphate. DSC data, solid content and IR spectrum showed that copoly(styrene/butyl acrylate/methyl methacrylate was produced. Batch emulsion polymerization technique gave the highest particle size i.e. 615 nm and also the highest % conversion of monomer i.e. 97%. The more concentration of monomer was seeded to initial charge gave greater particle size and greater poly dispersity index.

Voltammetric determination of butylated hydroxyanisol in biodiesel, mineral and synthetic oils using gold electrode

Czech Academy of Sciences Publication Activity Database

Tomášková, M.; Chýlková, J.; Jehlička, V.; Navrátil, Tomáš; Šelešovská, R.

2013-01-01

Roč. 19, č. 2013 (2013), s. 155-172 ISSN 1211-5541 R&D Projects: GA ČR(CZ) GAP208/12/1645 Grant - others:GA ČR(CZ) GP13-21409P Program:GP Institutional support: RVO:61388955 Keywords : voltammetry * butylated hydroxyanisol * gold electrode Subject RIV: CF - Physical ; Theoretical Chemistry

Coal anion structure and chemistry of coal alkylation. Fourth quarterly progress report, December 1, 1977--February 28, 1978. [Carbon atoms in butyl groups

Energy Technology Data Exchange (ETDEWEB)

Stock, L.M.

1978-01-01

Three research problems are in progress. First, work is progressing well concerning the methods appropriate for the reductive alkylation of Illinois No. 6 coal samples. We have investigated the influence of the leaving group on the conversion of the Illinois coal to a soluble material. We find that the n-butyl iodide is more effective than other n-butyl halides. Second, preliminary results have been obtained concerning the distribution of hydrogen and deuterium atoms in the reaction of Illinois No. 6 coal samples with perdeuteriotetralin at 400/sup 0/C. Third, the nuclear magnetic resonance spectra of appropriate model compounds with n-butyl groups have been tabulated for comparison with the spectroscopic results obtained from coal alkylation products. Fourth, the chromatographic procedures necessary for the separation of the coal samples are being developed.

Tri-n-butyl phosphate - the universal solvent for the nuclear fuel cycle

International Nuclear Information System (INIS)

Naylor, A.; Eccles, H.

1988-01-01

Tri-n-butyl phosphates (TBP) is now Widely used in the processes of solvent extraction, especially in those, used in nuclear fuel cycle. Problems, related with actinide separation and purification, can be solved easily by accurate sampling of diluent, concentration and purification degree of a solvent, aqueous phase acidity and temperature. Physical and chemical properties of TBP, mechanism of actinide solvent extraction, TBP hydrolysis and radiolysis are considered

Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

Directory of Open Access Journals (Sweden)

Xiao Li-guang

2016-01-01

Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

Contribution to the study of uranyl salts in butyl phosphate solutions; Contribution a l'etude des solutions de sels d'uranyle dans les phosphates butyliques

Energy Technology Data Exchange (ETDEWEB)

Coulon, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1965-06-01

A spectroscopic study in the normal infrared region and involving the following associations: tri-alkyl phosphates (tri-butyl, tri-ethyl, tri-methyl), uranyl salts (nitrate, chloride, acetate) has confirmed the existence of an interaction between the phosphoryl group and the uranium atom, as shown by a movement of absorption band for the valency P = 0 from {approx} 1270 cm{sup -1} to {approx} 1180 cm{sup -1}. A study of the preparation, analysis and spectroscopy of the solids obtained by the precipitation of uranyl salts by acid butyl phosphates has been carried out. By infrared spectrophotometry it has been shown that the tri-butyl and di-butyl phosphates are associated in non-polar diluents even before the uranium is introduced. The extraction of uranyl salts from acid aqueous solutions by a diluted mixture of tri-butyl and di-butyl phosphates proceeds by different mechanisms according to the nature of the ion (nitrate or chloride). (author) [French] Une etude spectroscopique dans l'infrarouge moyen portant sur les associations: - phosphates trialcoyliques (tributylique - triethylique - trimethylique) - sels d'uranyle (nitrate, chlorure, acetate) a confirme l'existence d'une interaction entre le groupement phosphoryle et l'atome d'uranium, se manifestant par un deplacement de la bande d'absorption de la vibration de valence P = 0 de {approx} 1270 cm{sup -1} a {approx} 1180 cm{sup -1}. Une etude preparative, analytique et spectroscopique des solides obtenus par precipitation de sels d'uranyle par les phosphates butyliques acides a ete effectuee. La spectrophotomerie infrarouge met en evidence l'association, anterieure a toute introduction d'uranium, des phosphates tributylique et dibutylique dans des diluants non polaires. L'extraction de sels d'uranyle, d'une solution aqueuse acide par un melange dilue de phosphates tributylique et dibutylique, s'effectue suivant des processus differents a la nature de l'anion (nitrate ou chlorure). (auteur)

Solid state {sup 1}H spin-lattice relaxation and isolated-molecule and cluster electronic structure calculations in organic molecular solids: The relationship between structure and methyl group and t-butyl group rotation

Energy Technology Data Exchange (ETDEWEB)

Wang, Xianlong, E-mail: WangXianlong@uestc.edu.cn, E-mail: pbeckman@brynmawr.edu [Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, 4 North Jianshe Rd., 2nd Section, Chengdu 610054 (China); Mallory, Frank B. [Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States); Mallory, Clelia W. [Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States); Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323 (United States); Odhner, Hosanna R.; Beckmann, Peter A., E-mail: WangXianlong@uestc.edu.cn, E-mail: pbeckman@brynmawr.edu [Department of Physics, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States)

2014-05-21

We report ab initio density functional theory electronic structure calculations of rotational barriers for t-butyl groups and their constituent methyl groups both in the isolated molecules and in central molecules in clusters built from the X-ray structure in four t-butyl aromatic compounds. The X-ray structures have been reported previously. We also report and interpret the temperature dependence of the solid state {sup 1}H nuclear magnetic resonance spin-lattice relaxation rate at 8.50, 22.5, and 53.0 MHz in one of the four compounds. Such experiments for the other three have been reported previously. We compare the computed barriers for methyl group and t-butyl group rotation in a central target molecule in the cluster with the activation energies determined from fitting the {sup 1}H NMR spin-lattice relaxation data. We formulate a dynamical model for the superposition of t-butyl group rotation and the rotation of the t-butyl group's constituent methyl groups. The four compounds are 2,7-di-t-butylpyrene, 1,4-di-t-butylbenzene, 2,6-di-t-butylnaphthalene, and 3-t-butylchrysene. We comment on the unusual ground state orientation of the t-butyl groups in the crystal of the pyrene and we comment on the unusually high rotational barrier of these t-butyl groups.

Carbamoylcholine analogs as nicotinic acetylcholine receptor agonists--structural modifications of 3-(dimethylamino)butyl dimethylcarbamate (DMABC)

DEFF Research Database (Denmark)

Hansen, Camilla Petrycer; Jensen, Anders Asbjørn; Balle, Thomas

2009-01-01

Compounds based on the 3-(dimethylamino)butyl dimethylcarbamate (DMABC) scaffold were synthesized and pharmacologically characterized at the alpha(4)beta(2), alpha(3)beta(4,) alpha(4)beta(4) and alpha(7) neuronal nicotinic acetylcholine receptors (nAChRs). The carbamate functionality and a small...

Energetic Materials Center Report--Small-Scale Safety and Thermal Testing Evaluation of Butyl Nitrate

Energy Technology Data Exchange (ETDEWEB)

Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center; Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center

2013-04-26

Butyl Nitrate (BN) was examined by Small-Scale Safety and Thermal (SSST) Testing techniques to determine its sensitivity to impact, friction, spark and thermal exposure simulating handling and storage conditions. Under the conditions tested, the BN exhibits thermal sensitivity above 150 °C, and does not exhibit sensitive to impact, friction or spark.

Volumetric properties of the (tetrahydrofuran + water) and (tetra-n-butyl ammonium bromide + water) systems: Experimental measurements and correlations

International Nuclear Information System (INIS)

Belandria, Veronica; Mohammadi, Amir H.; Richon, Dominique

2009-01-01

In this communication, we report experimental density data for the binary mixtures of (water + tetrahydrofuran) and (water + tetra-n-butyl ammonium bromide) at atmospheric pressure and various temperatures. The densities were measured using an Anton Paar TM digital vibrating-tube densimeter. For the (tetrahydrofuran + water) system, excess molar volumes have been calculated using the experimental densities and correlated using the Redlich-Kister equation. The Redlich-Kister equation parameters have been adjusted on experimental results. The partial molar volumes and partial excess molar volumes at infinite dilution have also been calculated for each component. A simple density equation was finally applied to correlate the measured density of the (tetra-n-butyl ammonium bromide + water) system.

Formation of poly(butyl 2-cyanoacrylate) microcapsules and the microencapsulation of aqueous solutions of [125I]-labelled proteins

International Nuclear Information System (INIS)

Wood, D.A.; Whateley, T.L.; Florence, A.T.

1981-01-01

Some featrues of the polymerization reaction of butyl 2-cyanoacrylate at different aqueous/organic solvent interfaces have been investigated. In particular, the effects of pH and the presence of protein on the formation of microcapsules by in situ interfacial polymerization of butyl 2-cyanoacrylate in w/o emulsions have been studied. [ 125 I]-labelled proteins have been used to study the procedure as a method of microencapsulating enzymes or other proteins within potentially biodegradable membranes. Preliminary in vitro degradation studies suggest that degradation of the microcapsules is inhibited by low levels of their breakdown products, thus allowing the storage of the microcapsules as aqueous suspensions for prolonged periods in sealed containers. (Auth.)

Keggin type inorganic-organic hybrid material containing Mn(II) monosubstituted phosphotungstate and S-(+)-sec-butyl amine: Synthesis and characterization

Energy Technology Data Exchange (ETDEWEB)

Patel, Ketan [Chemistry Department, Faculty of Science, M.S. University of Baroda, Vadodara 390 002 (India); Patel, Anjali, E-mail: aupatel_chem@yahoo.com [Chemistry Department, Faculty of Science, M.S. University of Baroda, Vadodara 390 002 (India)

2012-02-15

Graphical abstract: A new organic-inorganic hybrid material containing Keggin type manganese substituted phosphotungstate and S-(+)-sec-butyl amine was synthesized and systematically characterized. Highlights: Black-Right-Pointing-Pointer New hybrid material comprising Mn substituted phosphotungstate (PW{sub 11}Mn) and S-(+)-sec-butyl amine (SBA) was synthesized. Black-Right-Pointing-Pointer The spectral studies reveal the attachment of SBA to the PW{sub 11}Mn without any distortion of structure. Black-Right-Pointing-Pointer The synthesized material comprises chirality. Black-Right-Pointing-Pointer The synthesized hybrid material can be used as a heterogeneous catalyst for carrying out asymmetric synthesis. -- Abstract: A new inorganic-organic POM-based hybrid material comprising Keggin type mono manganese substituted phosphotungstate and enantiopure S-(+)-sec-butyl amine was synthesized in an aqueous media by simple ligand substitution method. The synthesized hybrid material was systematically characterized in solid as well as solution by various physicochemical techniques such as elemental analysis, TGA, UV-vis, FT-IR, ESR and multinuclear solution NMR ({sup 31}P, {sup 1}H, {sup 13}C). The presence of chirality in the synthesized material was confirmed by CD spectroscopy and polarimeter. The above study reveals the attachment of S-(+)-sec-butyl amine to Keggin type mono manganese substituted phosphotungstate through N {yields} Mn bond. It also indicates the retainment of Keggin unit and presence of chirality in the synthesized material. An attempt was made to use the synthesized material as a heterogeneous catalyst for carrying out aerobic asymmetric oxidation of styrene using molecular oxygen. The catalyst shows the potential of being used as a stable recyclable catalytic material after simple regeneration without significant loss in conversion.

Effect of pomegranate peel extract on lipid and protein oxidation in beef meatballs during refrigerated storage.

Science.gov (United States)

Turgut, Sebahattin Serhat; Soyer, Ayla; Işıkçı, Fatma

2016-06-01

Antioxidant effect of pomegranate peel extract (PE) to retard lipid and protein oxidation was investigated in meatballs during refrigerated storage at 4±1°C. Concentrated lyophilised water extract of pomegranate peel was incorporated into freshly minced beef meat at 0.5% and 1% concentrations and compared with 0.01% butylated hydroxytoluene (BHT) as a reference and control (without any antioxidant). PE showed high phenolic content and antioxidant activity. In PE added samples, thiobarbituric acid reactive substances (TBARS) value, peroxide formation, loss of sulfhydryl groups and formation of protein carbonyls were lower than control (Pmeatballs prolonged the refrigerated storage up to 8 days. Addition of both 0.5 and 1% PE in meatballs reduced lipid and protein oxidation and improved sensory scores. These results indicated that PE was effective on retarding lipid and protein oxidation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stabilization of Neem Oil Biodiesel with Corn Silk Extract during Long-term Storage.

Science.gov (United States)

Ali, Rehab Farouk M; El-Anany, Ayman M

2017-02-01

The current study aimed to evaluate the antioxidant efficiency of different extracts of corn silk. In addition, the impact of corn silk extract on oxidative stability of neem biodiesel during storage was studied. The highest phenolics, DPPH radical scavenging and reducing power activities were recorded for methanol-water extract. The longest oxidation stability (10 h) was observed for biodiesel samples blended with 1000 ppm of corn silk extract (CSE). At the end of storage period the induction time of biodiesel samples mixed with 1000 ppm of CSE or butylated hydroxytoluene (BHT) were about 6.72 and 5.63 times as high as in biodiesel samples without antioxidants. Biodiesel samples blended with 1000 ppm of CSE had the lowest acidity at the end of storage period. Peroxide value of biodiesel samples containing 1000 ppm of CSE was about 4.28 times as low as in control sample without antioxidants.

Nitrates and NO-NSAIDs in cancer chemoprevention and therapy: in vitro evidence querying the NO donor functionality.

Science.gov (United States)

Dunlap, Tareisha; Abdul-Hay, Samer O; Chandrasena, R Esala P; Hagos, Ghenet K; Sinha, Vaishali; Wang, Zhiqiang; Wang, Huali; Thatcher, Gregory R J

2008-09-01

Properties of the NO-ASA family of NO-donating NSAIDs (NO-NSAIDs), notably NCX 4016 (mNO-ASA) and NCX 4040 (pNO-ASA), reported in more than one hundred publications, have included positive preclinical data in cancer chemoprevention and therapy. Evidence is presented that the antiproliferative, the chemopreventive (antioxidant/electrophile response element (ARE) activation), and the anti-inflammatory activity of NO-ASA in cell cultures is replicated by X-ASA derivatives that are incapable of acting as NO donors. pBr-ASA and mBr-ASA are conisogenic with NO-ASA, but are not NO donors. The biological activity of pNO-ASA is replicated by pBr-ASA; and both pNO-ASA and pBr-ASA are bioactivated to the same quinone methide electrophile. The biological activity of mNO-ASA is replicated by mBr-ASA; mNO-ASA and mBr-ASA are bioactivated to different benzyl electrophiles. The observed activity is likely initiated by trapping of thiol biomolecules by the quinone and benzyl electrophiles, leading to depletion of GSH and modification of Cys-containing sensor proteins. Whereas all NO-NSAIDs containing the same structural "linker" as NCX 4040 and NCX 4016 are anticipated to possess activity resulting from bioactivation to electrophilic metabolites, this expectation does not extend to other linker structures. Nitrates require metabolic bioactivation to liberate NO bioactivity, which is often poorly replicated in vitro, and NO bioactivity provided by NO-NSAIDs in vivo provides proven therapeutic benefits in mitigation of NSAID gastrotoxicity. The in vivo properties of X-ASA drugs await discovery.

INHALATION EXPOSURE TO METHYL TERT-BUTYL ETHER (MTBE) AND DIBROMOCHLOROMETHANE (DBCM) USING CONTINUOUS BREATH ANALYSIS

Science.gov (United States)

The oxygenate methyl tert-butyl ether (MTBE) has been added to gasoline to help meet national ambient air quality standards in those parts of the U.S. that are non-compliant for carbon monoxide. Although MTBE has provided important health benefits in terms of reduced haza...

Transdermal uptake of diethyl phthalate and di(n-butyl) phthalate directly from air: Experimental verification

DEFF Research Database (Denmark)

Weschler, Charles J.; Bekö, Gabriel; Koch, Holger M.

2015-01-01

of phthalate esters. Objectives: This study investigated transdermal uptake, directly from air, of diethyl phthalate (DEP) and di(n-butyl) phthalate (DnBP) in humans. Methods: In a series of experiments, six human participants were exposed for 6 hr in a chamber containing deliberately elevated air...

Process Intensification of Enzymatic Fatty Acid Butyl Ester Synthesis Using a Continuous Centrifugal Contactor Separator

NARCIS (Netherlands)

Ilmi, Miftahul; Abduh, Muhammad Yusuf; Hommes, Arne; Winkelman, Jozef; Hidayat, C.; Heeres, Hero

2018-01-01

Fatty acid butyl esters were synthesized from sunflower oil with 1-butanol using a homogeneous Rhizomucor miehei lipase in a biphasic organic (triglyceride, 1-butanol, hexane)– water (with enzyme) system in a continuous setup consisting of a cascade of a stirred tank reactor and a continuous

Formation of Germa-ketenimine on the Ge(100) Surface by Adsorption of tert-Butyl Isocyanide.

Science.gov (United States)

Shong, Bonggeun; Yoo, Jong Suk; Sandoval, Tania E; Bent, Stacey F

2017-06-28

Reactions of the (100) surfaces of Ge and Si with organic molecules have been generally understood within the concept of "dimers" formed by the 2 × 1 surface reconstruction. In this work, the adsorption of tert-butyl isocyanide on the Ge(100)-2 × 1 surface at large exposures is investigated under ultrahigh vacuum conditions. A combination of infrared spectroscopy, X-ray photoelectron spectroscopy, and temperature-programmed desorption experiments along with dispersion-corrected density functional theory calculations is used to determine the surface products. Upon adsorption of a dense monolayer of tert-butyl isocyanide, a product whose structure resembles a germa-ketenimine (N=C=Ge) with σ donation toward and π back-donation from the Ge(100) surface appears. Formation of this structure involves divalent-type surface Ge atoms that arise from cleavage of the Ge(100)-2 × 1 surface dimers. Our results reveal an unprecedented class of reactions of organic molecules at the Ge(100) surface.

Working-up sugar-beet molasses in the acetone-butyl alcohol plants in Poland

Energy Technology Data Exchange (ETDEWEB)

Logotkin, I S; Zaritskii, I M

1959-01-01

The basic setup common to all Polish acetone and butanol plants is the addition of rye or wheat meal to the fermentation. A culture of Clostridium acetobutylicum, after spore formation, is mixed in a special apparatus with the meal, where it is kept for 18 hours at 37/sup 0/ and then treated with molasses; a culture is prepared which is used later in the fermentor. Independently a mixture of meal and molasses is mixed in an autoclave with H/sub 2/O, sterilized, and cooled. The resulting mash is mixed in the fermentor with the culture mentioned, where the fermentation liberates CO/sub 2/ and hydrogen which are recovered. The mixture is then heated, distilled, and rectified, where, in addition to slops, the desired products are obtained. The Polish plants figure that for each long ton of sugar contained in the molasses they recover butyl alcohol 178.0, acetone 83.7, and ethanol 7.3kg, and they use in addition to the molasses and bacilli cultures 58.4 tons of steam and 16 kg of NaOH long ton of the acetone-butyl alcohol mixture recovered.

Crocus sativus L. (saffron for cancer chemoprevention: A mini review

Directory of Open Access Journals (Sweden)

Prasan R. Bhandari

2015-04-01

Full Text Available Cancer is one of the most feared diseases globally and there has been a sustained rise in its incidence in both developing and developed countries. Despite the growing therapeutic options for patients with cancer, their efficacy is time-limited and non-curative. Hence to overcome these drawbacks, an incessant screening for superior and safer drugs has been ongoing for numerous decades, resulting in the detection of anti-cancer properties of several phytochemicals. Chemoprevention using readily available natural substances from vegetables, fruits, herbs and spices is one of the significantly important approaches for cancer prevention in the present era. Among the spices, Crocus sativus L. (saffron; 番紅花 fān hóng huā has generated interest because pharmacological experiments have established numerous beneficial properties including radical scavenging, anti-mutagenic and immuno-modulating effects. The more powerful components of saffron are crocin, crocetin and safranal. Studies in animal models and with cultured human malignant cell lines have demonstrated antitumor and cancer preventive activities of saffron and its main ingredients. This review provides a brief insight into the anticancer properties of saffron and its components.

Separation of Poly(styrene-block-t-butyl methacrylate) Copolymers by Various Liquid Chromatography Techniques

Science.gov (United States)

Šmigovec Ljubič, Tina; Pahovnik, David; Žigon, Majda; Žagar, Ema

2012-01-01

The separation of a mixture of three poly(styrene-block-t-butyl methacrylate) copolymers (PS-b-PtBMA), consisting of polystyrene (PS) blocks of similar length and t-butyl methacrylate (PtBMA) blocks of different lengths, was performed using various chromatographic techniques, that is, a gradient liquid chromatography on reversed-phase (C18 and C8) and normal-phase columns, a liquid chromatography under critical conditions for polystyrene as well as a fully automated two-dimensional liquid chromatography that separates block copolymers by chemical composition in the first dimension and by molar mass in the second dimension. The results show that a partial separation of the mixture of PS-b-PtBMA copolymers can be achieved only by gradient liquid chromatography on reversed-phase columns. The coelution of the two block copolymers is ascribed to a much shorter PtBMA block length, compared to the PS block, as well as a small difference in the length of the PtBMA block in two of these copolymers, which was confirmed by SEC-MALS and NMR spectroscopy. PMID:22489207

The use tri-n-butyl phosphate in plutonium extraction. Radiolysis and recycling of the solvent (1963); Le phosphate de tri-n-butyle dans l'extraction du plutonium. Radiolyse et recyclage du solvant (1963)

Energy Technology Data Exchange (ETDEWEB)

Isaac, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

The work concerns the radiolysis and recycling of tri-n-butyl phosphate used as extraction solvent for plutonium. The radiolysis is studied on an industrial solvent using a cobalt 60 source. Figures are given for the yield of the mono- and di-butyl-phosphoric acids formed from the dry and water-saturated solvents and the influence of nitric acid on the formation of dibutyl-phosphoric acid is indicated. The recycling treatment of the solvent is reconsidered with a view to lowering the residual contamination due to fission products. The tests carried out on a solvent from the plutonium extraction plant at Marcoule show the efficiency of the sodium carbonate treatment. Of all the products studied, only caustic soda led to a better decontamination than sodium carbonate; in all cases however, the elimination of ruthenium is always incomplete. (author) [French] L'etude porte sur la radiolyse et le recyclage du phosphate de tri-n-butyle utilise comme solvant d'extraction du plutonium. La radiolyse est etudiee sur un solvant industriel a l'aide d'une source de cobalt 60. On donne les rendements de formation des acides mono- et dlbutylphosphoriques a partir de solvants secs et satures d'eau, et on montre l'influence de l'acide nitrique sur la formation de l'acide dibutylphosphorique. Le traitement de recyclage du solvant est repris en vue d'abaisser la contamination residuelle en produits de fission. Les essais, effectues sur un solvant provenant de l'usine d'extraction du plutonium de Marcoule, montrent l'efficacite du traitement au carbonate de sodium. De tous les reactifs etudies, seule la soude a donne une decontamination superieure au carbonate de sodium; mais dans tous les cas, l'elimination du ruthenium est toujours incomplete. (auteur)

Chemopreventive and therapeutic activity of dietary blueberry against estrogen-mediated breast cancer.

Science.gov (United States)

Jeyabalan, Jeyaprakash; Aqil, Farrukh; Munagala, Radha; Annamalai, Lakshmanan; Vadhanam, Manicka V; Gupta, Ramesh C

2014-05-07

Berries are gaining increasing importance lately for their chemopreventive and therapeutic potential against several cancers. In earlier studies, a blueberry-supplemented diet has shown protection against 17β-estradiol (E2)-mediated mammary tumorigenesis. This study tested both preventive and therapeutic activities of diet supplemented with whole blueberry powder (50:50 blend of Tifblue and Rubel). Animals received 5% blueberry diet, either 2 weeks prior to or 12 weeks after E2 treatment in preventive and therapeutic groups, respectively. Both interventions delayed the tumor latency for palpable mammary tumors by 28 and 37 days, respectively. Tumor volume and multiplicity were also reduced significantly in both modes. The effect on mammary tumorigenesis was largely due to down-regulation of CYP 1A1 and ER-α gene expression and also favorable modulation of microRNA (miR-18a and miR-34c) levels. These data suggest that the blueberry blend tested is effective in inhibiting E2-mediated mammary tumorigenesis in both preventive and therapeutic modes.

RATE CONSTANTS FOR THE REACTIONS OF OH RADICALS AND CL ATOMS WITH DI-N-PROPYL ETHER AND DI-N-BUTYL ETHER AND THEIR DEUTERATED ANALOGS. (R825252)

Science.gov (United States)

Using relative rate methods, rate constants for the gas-phase reactions of OH radicals and Cl atoms with di-n-propyl ether, di-n-propyl ether-d14, di-n-butyl ether and di-n-butyl ether-d18 have been measured at 296 ? 2 K and atmos...

Sulfuric acid functional zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts for alkylation of phenol with tert-butyl alcohol

International Nuclear Information System (INIS)

Jiang, Tingshun; Cheng, Jinlian; Liu, Wangping; Fu, Lie; Zhou, Xuping; Zhao, Qian; Yin, Hengbo

2014-01-01

Several zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts (SO 4 2− /Zr-MCM-48 and SO 4 2− /Al-MCM-48) were prepared by the impregnation method and their physicochemical properties were characterized by means of XRD, FT-IR, TEM, NH 3 -TPD and N 2 physical adsorption. Also, the catalytic activities of these solid acid catalysts were evaluated by the alkylation of phenol with tert-butyl alcohol. The effect of weight hour space velocity (WHSV), reaction time and reaction temperature on catalytic properties was also studied. The results show that the SO 4 2− /Zr-MCM-48 and SO 4 2− /Al-MCM-48 still have good mesoporous structure and long range ordering. Compared with the Zr (or Al)–MCM-48 samples, SO 4 2− /Zr-MCM-48 and SO 4 2− /Al-MCM-48 solid acid catalysts have strong acidity and exhibit high activities in alkylation reaction of phenol with tert-butyl alcohol. The SO 4 2− /Zr-MCM-48-25 (molar ratio of Si/Zr=0.04) catalyst was found to be the most promising and gave the highest phenol conversion among all catalysts. A maximum phenol conversion of 91.6% with 4-tert-butyl phenol (4-TBP) selectivity of 81.8% was achieved when the molar ratio of tert-butyl alcohol:phenol is 2:1, reaction time is 2 h, the WHSV is 2 h −1 and the reaction temperature is 140 °C. - Highlights: • Sulfuric acid functional mesoporous solid acid catalysts were prepared via impregnation method. • The alkylation of phenol with tert-butyl alcohol was carried out over these solid acid catalysts. • The catalytic activity of SO 4 2− /Zr-MCM-48-25 catalyst is much higher than that of the others. • A maximum phenol conversion of 91.6% was achieved under optimum reaction conditions for SO 4 2− /Zr-MCM-48-25

Photostabilization of Rhodamine 6G in acetone by β-carotene and t-butyl hydroxyanisole

OpenAIRE

Aoki, Keisuke; Matsuda, Masahiro; Yamamoto, Daisuke; Abe, Yasuhiro; Akutsu, Shinya; Fujita, Koichi; Doi, Kazutaka; Kobayashi, Masami

2011-01-01

The photostability of Rhodamine 6G is of crucial importance for the organic light-emitting display of mobilephones. Photobleaching of Rhodamine 6G in acetone was not protected by β-carotene, but was efficientlyphotostabilized by t-butyl hydroxyanisole. The results indicate that photobleaching of Rhodamine 6G inacetone was not caused by singlet oxygen but some radical species.

A Case of Successful Ablation of a Gastrophrenic Fistula with n-Butyl-2-Cyanoacrylate

Directory of Open Access Journals (Sweden)

Ashish Mahajan

2008-01-01

Full Text Available A 79-year-old woman with a fistula between a subphrenic abscess and the fundus of the stomach was successfully treated with n-Butyl-2-Cyanoacrylate. Conservative management had failed. Clinical presentation, treatment progress and imaging findings by computed tomography scan, ultrasound, gastroscopy and fluoroscopy are presented, along with a brief review of the relevant literature.

Bilateral transrenal ureteral occlusion by means of n-butyl cyanoacrylate and AMPLATZER vascular plug

Directory of Open Access Journals (Sweden)

Rosario F Grasso

2014-01-01

Full Text Available AMPLATZER vascular plug is a widely used embolic agent. In the present paper, we present a case of an 86-year-old female patient who underwent bilateral ureteral occlusion by means of AMPLATZER vascular plug II coupled to n-butyl cyanoacrylate (NBCA because of recurring pyelonephritis following cystectomy with subsequent bilateral ureterosigmoidostomy (sec. Mainz type II.

Transformation mechanism of n-butyl terminated Si nanoparticles embedded into Si1-xCx nanocomposites mixed with Si nanoparticles and C atoms

International Nuclear Information System (INIS)

Shin, J.W.; Oh, D.H.; Kim, T.W.; Cho, W.J.

2009-01-01

Bright-field transmission electron microscopy (TEM) images, high-resolution TEM (HRTEM) images, and fast-Fourier transformed electron-diffraction patterns showed that n-butyl terminated Si nanoparticles were aggregated. The formation of Si 1-x C x nanocomposites was mixed with Si nanoparticles and C atoms embedded in a SiO 2 layer due to the diffusion of C atoms from n-butyl termination shells into aggregated Si nanoparticles. Atomic force microscopy (AFM) images showed that the Si 1-x C x nanocomposites mixed with Si nanoparticles and C atoms existed in almost all regions of the SiO 2 layer. The formation mechanism of Si nanoparticles and the transformation mechanism of n-butyl terminated Si nanoparticles embedded into Si 1-x C x nanocomposites mixed with Si nanoparticles and C atoms are described on the basis of the TEM, HRTEM, and AFM results. These results can help to improve the understanding of the formation mechanism of Si nanoparticles.

Two-year drinking water carcinogenicity study of methyl tertiary-butyl ether (MTBE) in Wistar rats.

Science.gov (United States)

Dodd, Darol; Willson, Gabrielle; Parkinson, Horace; Bermudez, Edilberto

2013-07-01

Methyl tertiary-butyl ether (MTBE) has been used as a gasoline additive to reduce tailpipe emissions and its use has been discontinued. There remains a concern that drinking water sources have been contaminated with MTBE. A two-year drinking water carcinogenicity study of MTBE was conducted in Wistar rats (males, 0, 0.5, 3, 7.5 mg ml(-1); and females, 0, 0.5, 3, and 15 mg ml(-1)). Body weights were unaffected and water consumption was reduced in MTBE-exposed males and females. Wet weights of male kidneys were increased at the end of two years of exposure to 7.5 mg ml(-1) MTBE. Chronic progressive nephropathy was observed in males and females, was more severe in males, and was exacerbated in the high MTBE exposure groups. Brain was the only tissue with a statistically significant finding of neoplasms. One astrocytoma (1/50) was found in a female rat (15 mg ml(-1)). The incidence of brain astrocytomas in male rats was 1/50, 1/50, 1/50 and 4/50 for the 0, 0.5, 3 and 7.5 mg ml(-1) exposure groups, respectively. This was a marginally significant statistical trend, but not statistically significant when pairwise comparisons were made or when multiple comparisons were taken into account. The incidence of astrocytoma fell within historical control ranges for Wistar rats, and the brain has not been identified as a target organ following chronic administration of MTBE, ethyl tert-butyl ether, or tertiary butyl alcohol (in drinking water) to mice and rats. We conclude that the astrocytomas observed in this study are not associated with exposure to MTBE. Copyright © 2011 John Wiley & Sons, Ltd.

A study of butyl acetate synthesis. 4-reaction kinetics

Directory of Open Access Journals (Sweden)

Álvaro Orjuela Londoño

2006-05-01

Full Text Available This work was aimed at studying liquid-phase acetic acid and butyl alcohol esterification reaction (P atm =0.76 Bar,using an ion exchange resin (Lewatit K-2431 as catalyst. The effect of the absence of internal and external mass transport on catalyst particles was established in the research conditions used here. A set of assays to determine the effect of catalyst load (0.5%, 1%, 2% w/w temperature (73°C, 80°C, 87°C and molar ratio (1:2, 1:1, 2:1 acid/alcohol on reaction rate was carried out and both LHHW and pseudo-homogeneous kinetic expressions were obtained, these being in good agreement with the experimental data.

Cancer Chemoprevention Effects of Ginger and its Active Constituents: Potential for New Drug Discovery.

Science.gov (United States)

Wang, Chong-Zhi; Qi, Lian-Wen; Yuan, Chun-Su

2015-01-01

Ginger is a commonly used spice and herbal medicine worldwide. Besides its extensive use as a condiment, ginger has been used in traditional Chinese medicine for the management of various medical conditions. In recent years, ginger has received wide attention due to its observed antiemetic and anticancer activities. This paper reviews the potential role of ginger and its active constituents in cancer chemoprevention. The phytochemistry, bioactivity, and molecular targets of ginger constituents, especially 6-shogaol, are discussed. The content of 6-shogaol is very low in fresh ginger, but significantly higher after steaming. With reported anti-cancer activities, 6-shogaol can be served as a lead compound for new drug discovery. The lead compound derivative synthesis, bioactivity evaluation, and computational docking provide a promising opportunity to identify novel anticancer compounds originating from ginger.

In vitro antioxidant activities of extract and oil from roselle (Hibiscus sabdariffa L.) seed against sunflower oil autoxidation.

Science.gov (United States)

Nyam, K L; Teh, Y N; Tan, C P; Kamariah, L

2012-08-01

In order to overcome the stability problems of oils and fats, synthetic antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) have widespread use as food additives in many countries. Recent reports reveal that these compounds may be implicated in many health risks, including cancer and carcinogenesis. Hence, there is a move towards the use of natural antioxidants of plant origin to replace these synthetic antioxidants. In this study, roselle seed oil (RSO) and extract (RSE) were mixed with sunflower oil, respectively to monitor degradation rate and investigate antioxidant activity during accelerated storage. The antioxidant activity was found to stabilise sunflower oil of various samples and in the order of RSE>RSO>tocopherol>sunflower oil. The total percentage increased after 5 days of storage period in free fatty acid (FFA), peroxide value (PV) and anisidine value (AV). Total oxidation value (TOx) of sunflower oil supplemented with 1500 ppm RSE was 33.3%, 47.7%, 14.5%, and 45.5%, respectively. While the total percentage increased under different analysis methods, sunflower oil supplemented with 5% RSO was 17.2%, 60.4%, 36.2% and 59.0% in the order of FFA, PV, AV and TOTOX. Both RSO and RSE were found to be more effective in stabilisation of sunflower oil compared to tocopherol. Total phenolic content of RSE was 46.40 +/- 1.51 mg GAE/100g of oil while RSO was 12.51 +/- 0.15 mg GAE/ 100g of oil. The data indicates that roselle seed oil and seed extract are rich in phenolics and antioxidant activities and may be a potential source of natural antioxidants.

Liquid chromatographic determination of seven antioxidants in dry food.

Science.gov (United States)

Page, B D; Charbonneau, C F

1989-01-01

The liquid chromatographic determinative step of the official method for propyl gallate, trihydroxybutyrophenone, tert-butylhydroquinone, nordihydroguaiaretic acid, butylated hydroxyanisole (BHA), 3,5-di-tert-butyl-4-hydroxymethylphenol, and butylated hydroxytoluene (BHT) in fats and oils has been applied to their determination in a number of dry foods. A representative sample (10 g) is homogenized first with hexane (25 mL), then with 5 mL added water, and finally with 75 mL added acetonitrile. The hexane and acetonitrile are decanted, filtered, and separated; the hexane and rehydrated food are reextracted with 2 additional portions of acetonitrile, and the combined acetonitrile extracts are concentrated and diluted to 10 mL. An aliquot is analyzed as described in the official method, using a 150 x 4.6 mm 5 microns C-18 column. The need for rehydration to maximize the recovery of BHA and other antioxidants from marketplace dry food samples such as potato flakes, dry coffee whiteners, and dessert topping mixes was demonstrated. Rehydration was not required for cheese snacks, breakfast cereals, cake mixes, and some other foods. The need for rehydration should be determined by analyzing other foods with and without the addition of water. Potato and corn chips, popcorn and cheese snacks, breakfast cereals, dry beverage mixes, rice, potato flakes, french fried potatoes, and cake mixes were spiked with the above antioxidants at 10-50 ppm. Overall recoveries ranged from 64.3 to 105.6% and repeatabilities ranged from 0.7 to 10.8%. A total of 109 samples of the above foods were analyzed, and 64% contained detectable (greater than 1-2 ppm) antioxidants, mainly BHA and BHT.

On the interaction of molybdenum cyanide complexes with hydroperoxide of tertiary butyl

International Nuclear Information System (INIS)

Vretsena, N.B.; Nikipanchuk, M.V.; Chernyak, B.I.

1979-01-01

Conducted is investigation of interaction of potassium dioxotetracyanomolybdate (4) K 4 [MoO 2 (CN) 4 ], potassium oxotetracyanomolybdate (2) K 4 [MoO(CN) 4 ] and potassium tetracyanomolybdate K 4 [Mo(CN) 4 ] in CCl 4 and hydroperoxide of tertiary butyl medium, (HPTB). Shown is the process complex mechanism which leads to molybdenum oxidation in complexes and also to coordination and HPTB decomposition. Calculated are parameters of complex formation process of molybdenum with HPTB cyanide complexes

Simultaneous clostridial fermentation, lipase-catalyzed esterification, and ester extraction to enrich diesel with butyl butyrate

NARCIS (Netherlands)

Berg, C. van den; Heeres, A.S.; Wielen, L.A.M. van der; Straathof, A.J.J.

2013-01-01

The recovery of 1-butanol from fermentation broth is energy-intensive since typical concentrations in fermentation broth are below 20gL -1. To prevent butanol inhibition and high downstream processing costs, we aimed at producing butyl esters instead of 1-butanol. It is shown that it is possible to

Gene mdpC plays a regulatory role in the methyl-tert-butyl ether degradation pathway of Methylibium petroleiphilum strain PM1.

Science.gov (United States)

Joshi, Geetika; Schmidt, Radomir; Scow, Kate M; Denison, Michael S; Hristova, Krassimira R

2015-04-01

Among the few bacteria known to utilize methyl tert-butyl ether (MTBE) as a sole carbon source, Methylibium petroleiphilum PM1 is a well-characterized organism with a sequenced genome; however, knowledge of the genetic regulation of its MTBE degradation pathway is limited. We investigated the role of a putative transcriptional activator gene, mdpC, in the induction of MTBE-degradation genes mdpA (encoding MTBE monooxygenase) and mdpJ (encoding tert-butyl alcohol hydroxylase) of strain PM1 in a gene-knockout mutant mdpC(-). We also utilized quantitative reverse transcriptase PCR assays targeting genes mdpA, mdpJ and mdpC to determine the effects of the mutation on transcription of these genes. Our results indicate that gene mdpC is involved in the induction of both mdpA and mdpJ in response to MTBE and tert-butyl alcohol (TBA) exposure in PM1. An additional independent mechanism may be involved in the induction of mdpJ in the presence of TBA. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Migration of strontium, cesium, and europium from poly(butyl acrylate)/phosphate/composites prepared using gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Alhassanieh, O., E-mail: cscientific@aec.org.s [Nuclear and Radiochemistry Division, Chemistry Department, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic); Ajji, Z. [Polymer Technology Division, Radiation Technology Department, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic); Alkourdi, H.; Haloum, D. [Nuclear and Radiochemistry Division, Chemistry Department, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic)

2011-02-15

Composites based on natural phosphate powder and the monomer N-butyl acrylate have been prepared by means of gamma irradiation. The conversion of polymerization was followed up with respect to the irradiation dose using thermogravimetric analyzer (TGA). A total polymerization conversion was achieved by exposure of the samples to a dose of 10 kGy. A thermomechanical analyzer (TMA) was used to locate the region of the glass transition temperatures (T{sub g}) using the mode with alternative variable force; the mode with constant force was used to determine the T{sub g} of the pure polymer and the composite prepared at the same irradiation dose. The T{sub g} of the pure poly(butyl acrylate) is -51.41 {sup o}C, and the T{sub g} of poly(butyl acrylate)/phosphate/composites is -46.54 {sup o}C. The distribution of {sup 137}Cs, {sup 152}Eu, and {sup 85}Sr in a solid-aqueous system, a composite of phosphate-polybutyl acrylate in contact with groundwater, was investigated using {gamma}-spectrometry. The effect of contact time, pH, and the concentration of concurrent elements (Na, Ca, and La) were studied. The results were compared with earlier results with phosphate alone in the solid phase. The ability of the produced composites to keep the studied radioisotopes in the solid phase is much higher than mineral phosphate. This improvement is more remarkable by strontium and cesium than europium, due to its high element ratio in the solid phase in phosphate experiments.

Dried extracts of Encholirium spectabile (Bromeliaceae) present antioxidant and photoprotective activities in vitro

Science.gov (United States)

de Oliveira, Raimundo Gonçalves; Souza, Grasielly Rocha; Guimarães, Amanda Leite; de Oliveira, Ana Paula; Silva Morais, Amanda Caroline; da Cruz Araújo, Edigênia Cavalcante; Nunes, Xirley Pereira; Almeida, Jackson Roberto Guedes da Silva

2013-01-01

The antioxidant and photoprotective activities of dried extracts from the leaves of Encholirium spectabile were investigated. It was also evaluated the total phenolic and flavonoid contents by the Folin–Ciocalteu and aluminum chloride methods, respectively. Antioxidant activities of the extracts were evaluated by using of 2,2-diphenyl-1-picrylhydrazil (DPPH) radical scavenging and β-carotene–linoleic acid bleaching and compared with ascorbic acid, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) used as reference compounds. The photoprotective effect was evaluated by the spectrophotometric method. The most significant total phenolic and flavonoid contents was of 188.50 ± 27.50 mg of gallic acid equivalent/g and 129.70 ± 4.59 mg of catechin equivalent/g, respectively, for chloroform fraction (Es-CHCl3). The Es-CHCl3 also presented the best antioxidant activity (IC50 25.35 ± 4.35 μg/ml) for DPPH scavenging. The ethanol extract (Es-EtOH), Es-CHCl3 and the fraction ethyl acetate (Es-AcOEt) showed characteristic absorption bands in regions UVB and UVA in a concentration-dependent manner. Es-CHCl3 presented the highest sun protection factor SPF (8.89 ± 2.11). It shows the possibility to use this extract as sunscreen in pharmaceutical preparations. PMID:24396251

Spectroscopic studies on the antioxidant activity of p-coumaric acid

Science.gov (United States)

Kiliç, Ismail; Yeşiloğlu, Yeşim

2013-11-01

p-coumaric acid (4-hydroxycinnamic acid), a phenolic acid, is a hydroxyl derivative of cinnamic acid. It decreases low density lipoprotein (LDL) peroxidation and reduces the risk of stomach cancer. In vitro radical scavenging and antioxidant capacity of p-coumaric acid were clarified using different analytical methodologies such as total antioxidant activity determination by ferric thiocyanate, hydrogen peroxide scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2‧-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity and superoxide anion radical scavenging, ferrous ions (Fe2+) chelating activity and ferric ions (Fe3+) reducing ability. p-Coumaric acid inhibited 71.2% lipid peroxidation of a linoleic acid emulsion at 45 μg/mL concentration. On the other hand, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and ascorbic acid displayed 66.8%, 69.8%, 64.5% and 59.7% inhibition on the peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, p-coumaric acid had an effective DPPHrad scavenging, ABTSrad + scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe3+) reducing power and ferrous ions (Fe2+) chelating activities. Also, those various antioxidant activities were compared to BHA, BHT, α-tocopherol and ascorbic acid as references antioxidant compounds. These results suggested that p-coumaric acid can be used in the pharmacological and food industry because of these properties.

Reversed-phase single drop microextraction followed by high-performance liquid chromatography with fluorescence detection for the quantification of synthetic phenolic antioxidants in edible oil samples.

Science.gov (United States)

Farajmand, Bahman; Esteki, Mahnaz; Koohpour, Elham; Salmani, Vahid

2017-04-01

The reversed-phase mode of single drop microextraction has been used as a preparation method for the extraction of some phenolic antioxidants from edible oil samples. Butylated hydroxyl anisole, tert-butylhydroquinone and butylated hydroxytoluene were employed as target compounds for this study. High-performance liquid chromatography followed by fluorescence detection was applied for final determination of target compounds. The most interesting feature of this study is the application of a disposable insulin syringe with some modification for microextraction procedure that efficiently improved the volume and stability of the solvent microdrop. Different parameters such as the type and volume of solvent, sample stirring rate, extraction temperature, and time were investigated and optimized. Analytical performances of the method were evaluated under optimized conditions. Under the optimal conditions, relative standard deviations were between 4.4 and 10.2%. Linear dynamic ranges were 20-10 000 to 2-1000 μg/g (depending on the analytes). Detection limits were 5-670 ng/g. Finally, the proposed method was successfully used for quantification of the antioxidants in some edible oil samples prepared from market. Relative recoveries were achieved from 88 to 111%. The proposed method had a simplicity of operation, low cost, and successful application for real samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synchrotron Photoionization Investigation of the Oxidation of Ethyl tert-Butyl Ether.

Science.gov (United States)

Winfough, Matthew; Yao, Rong; Ng, Martin; Catani, Katherine; Meloni, Giovanni

2017-02-23

The oxidation of ethyl tert-butyl ether (ETBE), a widely used fuel oxygenated additive, is investigated using Cl atoms as initiators in the presence of oxygen. The reaction is carried out at 293, 550, and 700 K. Reaction products are probed by a multiplexed chemical kinetics photoionization mass spectrometer coupled with the synchrotron radiation produced at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory. Products are identified on the basis of mass-to-charge ratio, ionization energies, and shape of photoionization spectra. Reaction pathways are proposed together with detected primary products.

High Solid Contents Copoly (Styrene/Butyl Acrylate-Cloisite 30B Nanocomposites

Directory of Open Access Journals (Sweden)

M. Mirzataheri

2013-03-01

Full Text Available Higher solid contents (20 % and 40 % nanocomposites of poly (styrene-co-butyl acrylate including higher content of Cloisite 30B (7 wt% and 10 wt % were prepared via miniemulsion polymerization. Stability of the final latexes proved outstanding combination of polymerization procedure and surfactants. Morphological studies revealed by TEM, SAX and XRD showed three structures of core-shell, armored and individual dispersion of clay layers within the polymer particles. The effect of Cloisite 30B content on the barrier properties presents excellent and wide use of these films for packaging and nanocoatings industries.

(N-Benzyl-N-ethyl-dithio-carbamato)di-tert-butyl-chloridotin(IV).

Science.gov (United States)

Abdul Muthalib, Amirah Faizah; Baba, Ibrahim; Mohamed Tahir, Mohamed Ibrahim; Tiekink, Edward R T

2011-02-26

The Sn(IV) atom in the title diorganotin dithio-carbamate, [Sn(C(4)H(9))(2)Cl(C(10)H(12)NS(2))], is penta-coordinated by an asymmetrically coordinating dithio-carbamate ligand, a Cl and two C atoms of the Sn-bound tert-butyl groups. The resulting C(2)ClS(2) donor set defines a coordination geometry inter-mediate between square pyramidal and trigonal bipyramidal with a slight tendency towards the former. In the crystal structure, C-H⋯π contacts link centrosymmetrically related mol-ecules into dimeric aggregates.

When does the fluazifop-P-butyl degradate, TFMP, leach through an agricultural loamy soil to groundwater?

DEFF Research Database (Denmark)

Vendelboe, Anders Lindblad; Norgaard, Trine; Olsen, Preben

2016-01-01

In intensely cultivated regions, it is crucial to have knowledge of the leaching potential related to pesticides in agricultural production. This is especially true in countries, like Denmark, that base its drinking water supply on untreated groundwater. Since fluazifop-P-butyl (FPB) is applied...

ATOM TRANSFER RADICAL POLYMERIZATION OF N-BUTYL METHACRYLATE IN AQUEOUS DISPERSED SYSTEMS: A MINIEMULSION APPROACH. (R826735)

Science.gov (United States)

Ultrasonication was applied in combination with a hydrophobe for the copper-mediated atom transfer radical polymerization of n-butyl methacrylate in an aqueous dispersed system. A controlled polymerization was successfully achieved, as demonstrated by a linear correlation between...

1-[(E-2-(5-tert-Butyl-2-hydroxyphenyldiazen-1-yl]naphthalen-2-ol

Directory of Open Access Journals (Sweden)

Hassiba Bougueria

2014-02-01

Full Text Available The non-H atoms of the title compound, C20H20N2O2, is located on a mirror plane except two methyl groups of the tert-butyl group. Intramolecular N—H...O hydrogen bonds exist between the hydroxy and diazenyl groups. In the crystal, molecules are linked by weak C—H...O hydrogen bonds into supramolecular chains running along the a-axis direction.

Fresh garlic extract inhibits Staphylococcus aureus biofilm formation under chemopreventive and chemotherapeutic conditions

Directory of Open Access Journals (Sweden)

Panan Ratthawongjirakul

2016-08-01

Full Text Available Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA are the leading aetiological pathogens of nosocomial infections worldwide. These bacteria form biofilms on both biotic and abiotic surfaces causing biofilm-associated infections. Within the biofilm, these bacteria might develop persistent and antimicrobial resistant characteristics resulting in chronic infections and treatment failures. Garlic exhibits broad pharmaceutical properties and inhibitory activities against S. aureus. We investigated the effects of aqueous fresh garlic extract on biofilm formation in S. aureus ATCC25923 and MRSA strains under chemopreventive and chemotherapeutic conditions. The viable bacteria and biofilm levels were quantified through colony count and crystal violet staining, respectively. The use of fresh garlic extract under both conditions significantly inhibited biofilm formation in S. aureus strains ATCC25923 and MRSA. Garlic could be developed as either a prophylactic or therapeutic agent to manage S. aureus biofilm-associated infections.

Studies on non dispersive solvent extraction for removal of dissolved di-butyl phosphate (DBP) from aqueous medium using hollow fiber membrane contactor

International Nuclear Information System (INIS)

Singh, Suman Kumar; Bindu, M.; Tripathi, S.C.; Gandhi, P.M.

2013-01-01

PUREX process is based on the principle of mass transfer by liquid liquid dispersion. Tri-n-butyl phosphate (TBP) is universal extractant for PUREX process which is employed for reprocessing the irradiated nuclear fuels for separation and recovery of fissile and fertile materials. The multi cycle solvent extraction processes encompass continuous extraction and stripping operations that are invariably carried out in pulsed columns. The continuous exposure of organic solvent (TBP) to high acidic and radioactive medium leads to decrease the solvent extraction efficiency as it degraded to different level producing di-butyl phosphate and mono-butyl phosphate in significant quantities. Efficiency of purex process decreases as di-butyl phosphate forms aqueous soluble complexes with uranium. Removal of such dissolved DBP from aqueous medium is of direct interest in reprocessing processes as this would enable to sustain the better efficiency of the process and also control the loss of fissile and fertile materials. The non-dispersive solvent extraction is a configuration of the conventional solvent-extraction process where a microporous membrane separates both the immiscible phases, one of which impregnates the membrane, thus bringing the liquid-liquid interface to one side of the membrane. This study is a preliminary evaluation of microporous hollow fiber membrane modules for the removal of dissolved DBP from acidic medium. The performance of the proposed system can be improved by optimizing controlling parameters of the process for quantitative transport of dissolved DBP from acidic medium in the purex process context

Pulse radiolysis study of reactions of alkyl and alkylperoxy radicals originating from methyl tert-butyl ether in the gas phase

DEFF Research Database (Denmark)

Langer, S.; Ljungström, E.; Ellermann, T.

1995-01-01

UV spectra and kinetics for the reactions of alkyl and alkylperoxy radicals from methyl tert-butyl ether (MTBE) were studied in 1 atm of SF6 by the pulse radiolysis-UV absorption technique. UV spectra for the radical mixtures were quantified from 215 to 340 nm. At 240 nm, sigma(R) = (2.6 +/- 0.4) X...... and the alkylperoxy radicals with NO and NO2 are (9.1 +/- 1.5) X 10(-13), (4.3 +/- 1.6) X 10(-12) and (1.2 +/- 0.3) X 10(-11) cm(3) molecule(-1) s(-1), respectively. The rate constants given above refer to reaction at the tert-butyl side of the molecule....

Feasibility, safety and effectiveness of combining home based malaria management and seasonal malaria chemoprevention in children less than 10 years in Senegal

DEFF Research Database (Denmark)

Tine, Roger C K; Ndour, Cheikh T; Faye, Babacar

2014-01-01

Home-based management of malaria (HMM) may improve access to diagnostic testing and treatment with artemisinin combination therapy (ACT). In the Sahel region, seasonal malaria chemoprevention (SMC) is now recommended for the prevention of malaria in children. It is likely that combinations...... of antimalarial interventions can reduce the malaria burden. This study assessed the feasibility, effectiveness and safety of combining SMC and HMM delivered by community health workers (CHWs)....

Increased chemopreventive effect by combining arctigenin, green tea polyphenol and curcumin in prostate and breast cancer cells

Science.gov (United States)

Wang, Piwen; Wang, Bin; Chung, Seyung; Wu, Yanyuan; Henning, Susanne M.; Vadgama, Jaydutt V.

2014-01-01

The low bioavailability of most flavonoids limits their application as anti-carcinogenic agents in humans. A novel approach of treatment with a mixture of bioactive compounds that share molecular anti-carcinogenic targets may enhance the effect on these targets at low concentrations of individual compound, thereby overcoming the limitations of reduced bioavailability. We therefore investigated whether a combination of three natural products arctigenin (Arc), a novel anti-inflammatory lignan from the seeds of Arctium lappa, green tea polyphenol (−)-epigallocatechin gallate (EGCG) and curcumin (Cur) increases the chemopreventive potency of individual compounds. LNCaP prostate cancer and MCF-7 breast cancer cells were treated with 2–4 mg/L (about 5–10μM) Cur, 1μM Arc and 40μM EGCG alone or in combination for 48h. In both cell lines treatment with the mixture of Cur, Arc and EGCG synergistically increased the antiproliferative effect. In LNCaP cells both Arc and EGCG increased the pro-apoptotic effect of Cur. Whereas in MCF-7 cells Arc increased the cell apoptosis of Cur while EGCG enhanced cell cycle arrest of Cur at G0/G1 phase. The strongest effects on cell cycle arrest and apoptosis were achieved by combining all three compounds in both cell lines. The combination treatment significantly increased the ratio of Bax to Bcl-2 proteins, decreased the activation of NFκB, PI3K/Akt and Stat3 pathways and cell migration compared to individual treatment. These results warrant in vivo studies to confirm the efficacy of this novel regimen by combining Arc and EGCG with Cur to enhance chemoprevention in both prostate and breast cancer. PMID:25243063

Inhibition of Pro-inflammatory and Anti-apoptotic Biomarkers during Experimental Oral Cancer Chemoprevention by Dietary Black Raspberries

Directory of Open Access Journals (Sweden)

Steve Oghumu

2017-10-01

Full Text Available Oral cancer continues to be a significant public health problem worldwide. Recently conducted clinical trials demonstrate the ability of black raspberries (BRBs to modulate biomarkers of molecular efficacy that supports a chemopreventive strategy against oral cancer. However, it is essential that a preclinical animal model of black raspberry (BRB chemoprevention which recapitulates human oral carcinogenesis be developed, so that we can validate biomarkers and evaluate potential mechanisms of action. We therefore established the ability of BRBs to inhibit oral lesion formation in a carcinogen-induced rat oral cancer model and examined potential mechanisms. F344 rats were administered 4-nitroquinoline 1-oxide (4NQO (20 µg/ml in drinking water for 14 weeks followed by regular drinking water for 6 weeks. At week 14, rats were fed a diet containing either 5 or 10% BRB, or 0.4% ellagic acid (EA, a BRB phytochemical. Dietary administration of 5 and 10% BRB reduced oral lesion incidence and multiplicity by 39.3 and 28.6%, respectively. Histopathological analyses demonstrate the ability of BRBs and, to a lesser extent EA, to inhibit the progression of oral cancer. Oral lesion inhibition by BRBs was associated with a reduction in the mRNA expression of pro-inflammatory biomarkers Cxcl1, Mif, and Nfe2l2 as well as the anti-apoptotic and cell cycle associated markers Birc5, Aurka, Ccna1, and Ccna2. Cellular proliferation (Ki-67 staining in tongue lesions was inhibited by BRBs and EA. Our study demonstrates that, in the rat 4NQO oral cancer model, dietary administration of BRBs inhibits oral carcinogenesis via inhibition of pro-inflammatory and anti-apoptotic pathways.

Solubility of carbon dioxide in secondary butyl alcohol at high pressures : experimental and modeling with CPA

NARCIS (Netherlands)

Raeissi, S.; Haghbaksh, R.; Florusse, L.J.; Peters, C.J.

2015-01-01

Mixtures of carbon dioxide and secondary butyl alcohol at high pressures are interesting for a range of industrial applications. Therefore, it is important to have trustworthy experimental data on the high-pressure phase behavior of this mixture over a wide range of temperatures. In addition, an

Effect of Polyhedral Oligomeric Silsesquioxane (POSS) Substituents on the Rheological Behavior in Butyl Methacrylate/POSS Copolymers

Science.gov (United States)

2008-10-27

was repeated twice, dissolving the product in chloroform and diethyl ether, respectively. The polymer was dried at 60 °C under vacuum overnight...the Tg of the i Bu remains the same. Table 1. Tg for Butyl Methacrylate-co- Propyl Methacryl POSS Polymers with Various POSS Substituents

Thermal and thermo-mechanical behavior of butyl based rubber exposed to silicon oil at elevated temperature

International Nuclear Information System (INIS)

Ali, S.; Ramzan, S.; Raza, R.; Ahmed, F.; Hussain, R.; Ullah, S.; Ali, S.

2013-01-01

Silica reinforced rubbers are used as chemical resistant seals at high temperature. In this study the effect of alkali and silicon oil on the thermal and thermo-mechanical properties of the silica reinforced butyl rubber exposed as an interface between two liquid media at elevated temperature is investigated. Rubber bladder containing alkaline solution was immersed in silicon oil at 195+-5 degree C for multiple cycles and loss in its thermal, thermo-mechanical and mechanical properties were studied by TGA, DMA and Tinius Olsen Testing Machine supported by FTIR and Optical microscopy. It was observed that the thermal and thermo-mechanical properties of butyl rubber were negatively affected due to leaching out of silica filler embedded in an organic matrix at elevated temperature. The thermal stability of exposed rubber was decreased around 200 degree C and the loss of storage modulus was observed up to 99.5% at -59 degree C. (author)

Dynamics of an excess hole in the 1-methyl-1-butyl-pyrrolidinium dicyanamide ionic-liquid

Science.gov (United States)

Wu, Fei; Xu, Changhui; Margulis, Claudio J.

2018-05-01

In a set of recent publications [C. J. Margulis et al., J. Am. Chem. Soc. 133, 20186 (2011); C. H. Xu et al., J. Am. Chem. Soc. 135, 17528 (2013); C. H. Xu and C. J. Margulis, J. Phys. Chem. B 119, 532 (2015); and K. B. Dhungana et al., J. Phys. Chem. B 121, 8809 (2017)], we explored for selected ionic liquids the early stages of excess charge localization and reactivity relevant both to electrochemical and radiation chemistry processes. In particular, Xu and Margulis [J. Phys. Chem. B 119, 532 (2015)] explored the dynamics of an excess electron in 1-methyl-1-butyl-pyrrolidinium dicyanamide. When electrons are produced from an ionic liquid, the more elusive hole species are also generated. Depending on the nature of cations and anions and the relative alignment of their electronic states in the condensed phase, the very early hole species can nominally be neutral radicals—if the electron is generated from anions—or doubly charged radical cations if their origin is from cations. However, in reality early excess charge localization is more complex and often involves more than one ion. The dynamics and the transient spectroscopy of the hole are the main objects of this study. We find that in the case of 1-methyl-1-butyl-pyrrolidinium dicyanamide, it is the anions that can most easily lose an electron becoming radical species, and that hole localization is mostly on anionic nitrogen. We also find that the driving force for localization of an excess hole appears to be smaller than that for an excess electron in 1-methyl-1-butyl-pyrrolidinium dicyanamide. The early transient hole species can absorb light in the visible, ultraviolet, and near infrared regions, and we are able to identify the type of states being connected by these transitions.

The synthesis of 1-11C-labelled ethyl, propyl, butyl and isobutyl iodides and examples of alkylation reactions

International Nuclear Information System (INIS)

Laangstroem, B.; Antoni, G.; Gullberg, P.; Halldin, C.; Naagren, K.; Rimland, A.; Svaerd, H.

1986-01-01

New 11 C-labelled precursors [1- 11 C]ethyl,[1- 11 C]propyl, [1- 11 C]butyl, and [1- 11 C]isobutyl iodides have been prepared by a 3-step reaction route using a one-pot system. The labelled iodides were obtained in 20-55#percent# radiochemical yields and 65-95#percent# radiochemical purities, with a total time for synthesis of the order of 10-14 min. The labelled iodides have been used in alkylation reactions with nitrogen, oxygen and carbon nucleophiles. The nitrogen alkylation reactions are exemplified by the synthesis of the analgetics N-[1- 11 C-ethyl]iodocaine and N-[1- 11 C-butyl] bupivacaine. The synthesis of 3-nitrophenyl[1- 11 C]propyl ether is also presented in this paper as an example of an oxygen alkylation. (author)

Substituted 2,2'-bipyridines by nickel-catalysis: 4,4'-di-tert-butyl-2,2'-bipyridine.

Science.gov (United States)

Buonomo, Joseph A; Everson, Daniel A; Weix, Daniel J

2013-11-01

A simple, ligand-free synthesis of the important bipyridyl ligand 4,4'-di- tert -butyl-2,2'-bipyridine is presented. 5,5'-bis(trifluoromethyl)-2,2'-bipyridine is also synthesized by the same protocol. The syntheses efficiently couple the parent 2-chlorpyridies by a nickel-catalyzed dimerization with manganese powder as the terminal reductant.

Hyoscine-N-Butyl-Bromide-Induced Hypotension and Myocardial Ischemia

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Guan-Liang Chen

2013-01-01

Full Text Available Hyoscine N-butyl bromide, also known as scopolamine, is a type of antimuscarinic agent. This drug is associated with numerous common side effects, including abdominal fullness, constipation, urinary retention, blurred vision, skin flushing, tachycardia, decreased sweating, and salivation. The most unfavorable side effect is hemodynamic instability. In the present case, hypotension and acute myocardial infarction developed after intravenous hyoscine injection as a premedication therapy for colonoscopy. It was difficult to differentiate the cause-effect relationship between myocardial infarction and hypotension. Because both conditions were present under drug effects, we considered 2 possible diagnoses. One was coronary spasm with cardiogenic shock, and the other was myocardial ischemic sequela due to shock status. The latter diagnosis was confirmed after a series of examinations.

A Review of the Potential of Phytochemicals from Prunus africana (Hook f. Kalkman Stem Bark for Chemoprevention and Chemotherapy of Prostate Cancer

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Richard Komakech

2017-01-01

Full Text Available Prostate cancer remains one of the major causes of death worldwide. In view of the limited treatment options for patients with prostate cancer, preventive and treatment approaches based on natural compounds can play an integral role in tackling this disease. Recent evidence supports the beneficial effects of plant-derived phytochemicals as chemopreventive and chemotherapeutic agents for various cancers, including prostate cancer. Prunus africana has been used for generations in African traditional medicine to treat prostate cancer. This review examined the potential roles of the phytochemicals from P. africana, an endangered, sub-Saharan Africa plant in the chemoprevention and chemotherapy of prostate cancer. In vitro and in vivo studies have provided strong pharmacological evidence for antiprostate cancer activities of P. africana-derived phytochemicals. Through synergistic interactions between different effective phytochemicals, P. africana extracts have been shown to exhibit very strong antiandrogenic and antiangiogenic activities and have the ability to kill tumor cells via apoptotic pathways, prevent the proliferation of prostate cancer cells, and alter the signaling pathways required for the maintenance of prostate cancer cells. However, further preclinical and clinical studies ought to be done to advance and eventually use these promising phytochemicals for the prevention and chemotherapy of human prostate cancer.

SIRT1 exhibits antioxidative effects in HT22 cells induced by tert-butyl alcohol.

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Ma, Junxiang; Song, Dongmei; Zhang, Yuanyuan; Chen, Li; Zhang, Shixuan; Jia, Jiaxin; Chen, Tian; Guo, Caixia; Tian, Lin; Gao, Ai; Niu, Piye

2018-02-01

Tertiary butyl alcohol (TBA) is a principal metabolite of methyl tertiary-butyl ether (MTBE), a common pollutant worldwide in the ground or underground water, which is found to produce nervous system damage. Nevertheless, few data regarding the effects of TBA has been reported. Studies indicated that oxidative stress plays a pivotal role in MTBE neurotoxic mechanism. Sirtuin 1 (SIRT1) has been reported to exert a neuroprotective effect on various neurologic diseases via resistance to oxidative stress by deacetylating its substrates. In this study, we examined levels of oxidative stress after exposure to TBA for 6 h in HT22 cells and HT22 cells with SIRT1 silencing (transfected with SIRT1 siRNA) or high expression (preconditioned with agonists SRT1720). We found that TBA activated oxidative stress by increasing generation of intracellular reactive oxygen species (ROS), malondialdehyde (MDA) and Oxidized glutathione (GSSG), and decreasing contents of superoxide dismutase (SOD) and glutathione reductase (GSH). In additional, levels of TBA-induced oxidative stress were aggravated when SIRT1 silenced but alleviated when SIRT1 enhanced. Our study indicated that SIRT1 mitigated oxidative stress induced by TBA. © 2017 Wiley Periodicals, Inc.

Biodegradation of Methyl tert-Butyl Ether by Co-Metabolism with a Pseudomonas sp. Strain

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Shanshan Li

2016-09-01

Full Text Available Co-metabolic bioremediation is supposed to be an impressive and promising approach in the elimination technology of methyl tert-butyl ether (MTBE, which was found to be a common pollutant worldwide in the ground or underground water in recent years. In this paper, bacterial strain DZ13 (which can co-metabolically degrade MTBE was isolated and named as Pseudomonas sp. DZ13 based on the result of 16S rRNA gene sequencing analysis. Strain DZ13 could grow on n-alkanes (C5-C8, accompanied with the co-metabolic degradation of MTBE. Diverse n-alkanes with different carbon number showed a significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA. When Pseudomonas sp. DZ13 co-metabolically degraded MTBE with n-pentane as the growth substrate, a higher MTBE-degrading rate (Vmax = 38.1 nmol/min/mgprotein, Ks = 6.8 mmol/L and lower TBA-accumulation was observed. In the continuous degradation experiment, the removal efficiency of MTBE by Pseudomonas sp. Strain DZ13 did not show an obvious decrease after five times of continuous addition.

Dissolution of uranium dioxide in supercritical carbon dioxide modified with tri-n-butyl phosphate-hydrogen peroxide

International Nuclear Information System (INIS)

Kanekar, A.S.; Pathak, P.N.; Mohapatra, P.K.; Manchanda, V.K.

2009-01-01

Direct dissolution of uranium dioxide in supercritical carbon dioxide modified with tri-n-butyl phosphate (TBP) has been attempted. The effects of TBP concentration and pressure on the extraction of uranium have been studied. Addition of hydrogen peroxide in the modifier enhances the dissolution/extraction of uranium. (author)

Portal Hypertension Secondary to Spontaneous Arterio-Portal Venous Fistulas: Transcatheter Arterial Embolization with n-Butyl Cyanoacrylate and Microcoils

International Nuclear Information System (INIS)

Yamagami, Takuji; Nakamura, Toshiyuki; Nishimura, Tsunehiko

2000-01-01

We report a 73-year-old man with recurrent variceal bleeding due to portal hypertension caused by multiple intrahepatic arterio-portal venous fistulas, which were successfully occluded by embolization with n-butyl cyanoacrylate and micro-coils

Ultrasonic promoted catalyst-free N-formylation of amines in neutral ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate

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Vinod T. Kamble

2017-05-01

Full Text Available A catalyst-free, simple and efficient protocol for N-formylation of alkyl, aryl, and heteroaryl amines with formic acid under ultrasonic irradiation at room temperature using 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim]BF4 as a neutral medium is described.

Hepatic Encephalopathy Secondary to Intrahepatic Portosystemic Venous Shunt: Balloon-Occluded Retrograde Transvenous Embolization with n-Butyl Cyanoacrylate and Microcoils

International Nuclear Information System (INIS)

Yamagami, Takuji; Nakamura, Toshiyuki; Iida, Shigeharu; Kato, Takeharu; Tanaka, Osamu; Matsushima, Shigenori; Ito, Hirotoshi; Okuyama, Chio; Ushijima, Yo; Shiga, Kensuke; Nishimura, Tsunehiko

2002-01-01

We report a 70-year-old woman with hepatic encephalopathy due to an intrahepatic portosystemic venous shunt that was successfully occluded by percutaneous transcatheter embolization with n-butyl cyanoacrylate and microcoils

Sulfuric acid functional zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts for alkylation of phenol with tert-butyl alcohol

Energy Technology Data Exchange (ETDEWEB)

Jiang, Tingshun, E-mail: tshjiang@mail.ujs.edu.cn; Cheng, Jinlian; Liu, Wangping; Fu, Lie; Zhou, Xuping; Zhao, Qian; Yin, Hengbo

2014-10-15

Several zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts (SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48) were prepared by the impregnation method and their physicochemical properties were characterized by means of XRD, FT-IR, TEM, NH{sub 3}-TPD and N{sub 2} physical adsorption. Also, the catalytic activities of these solid acid catalysts were evaluated by the alkylation of phenol with tert-butyl alcohol. The effect of weight hour space velocity (WHSV), reaction time and reaction temperature on catalytic properties was also studied. The results show that the SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48 still have good mesoporous structure and long range ordering. Compared with the Zr (or Al)–MCM-48 samples, SO{sub 4}{sup 2−}/Zr-MCM-48 and SO{sub 4}{sup 2−}/Al-MCM-48 solid acid catalysts have strong acidity and exhibit high activities in alkylation reaction of phenol with tert-butyl alcohol. The SO{sub 4}{sup 2−}/Zr-MCM-48-25 (molar ratio of Si/Zr=0.04) catalyst was found to be the most promising and gave the highest phenol conversion among all catalysts. A maximum phenol conversion of 91.6% with 4-tert-butyl phenol (4-TBP) selectivity of 81.8% was achieved when the molar ratio of tert-butyl alcohol:phenol is 2:1, reaction time is 2 h, the WHSV is 2 h{sup −1} and the reaction temperature is 140 °C. - Highlights: • Sulfuric acid functional mesoporous solid acid catalysts were prepared via impregnation method. • The alkylation of phenol with tert-butyl alcohol was carried out over these solid acid catalysts. • The catalytic activity of SO{sub 4}{sup 2−}/Zr-MCM-48-25 catalyst is much higher than that of the others. • A maximum phenol conversion of 91.6% was achieved under optimum reaction conditions for SO{sub 4}{sup 2−}/Zr-MCM-48-25.

Mitochondrial uncouplers with an extraordinary dynamic range.

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Lou, Phing-How; Hansen, Birgit S; Olsen, Preben H; Tullin, Søren; Murphy, Michael P; Brand, Martin D

2007-10-01

We have discovered that some weak uncouplers (typified by butylated hydroxytoluene) have a dynamic range of more than 10(6) in vitro: the concentration giving measurable uncoupling is less than one millionth of the concentration causing full uncoupling. They achieve this through a high-affinity interaction with the mitochondrial adenine nucleotide translocase that causes significant but limited uncoupling at extremely low uncoupler concentrations, together with more conventional uncoupling at much higher concentrations. Uncoupling at the translocase is not by a conventional weak acid/anion cycling mechanism since it is also caused by substituted triphenylphosphonium molecules, which are not anionic and cannot protonate. Covalent attachment of the uncoupler to a mitochondrially targeted hydrophobic cation sensitizes it to membrane potential, giving a small additional effect. The wide dynamic range of these uncouplers in isolated mitochondria and intact cells reveals a novel allosteric activation of proton transport through the adenine nucleotide translocase and provides a promising starting point for designing safer uncouplers for obesity therapy.

Trichomes and chemical composition of the volatile oil of Trichogonia cinerea (Gardner R. M. King & H. Rob. (Eupatorieae, Asteraceae

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YANNE S. FERNANDES

2016-03-01

Full Text Available Trichogonia cinerea is endemic to Brazil and occurs in areas of cerrado and campo rupestre. In this study, we characterized the glandular and non-glandular trichomes on the aerial parts of this species, determined the principal events in the development of the former, and identified the main constituents of the volatile oil produced in its aerial organs. Fully expanded leaves, internodes, florets, involucral bracts, and stem apices were used for the characterization of trichomes. Leaves, internodes, florets, and involucral bracts were examined by light microscopy and scanning electron microscopy, whereas stem apices were examined only by light microscopy. Branches in the reproductive phase were used for the extraction and determination of the composition of the volatile oil. The species has three types of glandular trichomes, biseriate vesicular, biseriate pedunculate, and multicellular uniseriate, which secrete volatile oils and phenolic compounds. The major components identified in the volatile oil were 3,5-muuroladiene (39.56% and butylated hydroxytoluene (13.07%.

Membrane lipid peroxidation by UV-A: Mechanism and implications

International Nuclear Information System (INIS)

Bose, B.; Agarwal, S.; Chatterjee, S.N.

1990-01-01

UV-A produced a dose-dependent linear increase of lipid peroxidation in liposomal membrane, as detected by the assay of (i) conjugated dienes, (ii) lipid hydroperoxides, (iii) malondialdehydes (MDA), and (iv) the fluorescent adducts formed by the reaction of MDA with glycine and also a linear dose-dependent increase of [ 14 C]glucose efflux from the liposomes. UV-A-induced MDA production could not be inhibited by any significant degree by sodium formate, dimethyl sulfoxide, EDTA, or superoxide dismutase but was very significantly inhibited by butylated hydroxytoluene, alpha-tocopherol, sodium azide, L-histidine, dimethylfuran, and beta-carotene. MDA formation increased with an increase in the D 2 O content in water, leading to a maximal amount of nearly 50% enhancement of lipid peroxidation in 100% D 2 O vis-a-vis water used as dispersion medium. The experimental findings indicate the involvement of singlet oxygen as the initiator of the UV-A-induced lipid peroxidation

INHIBITION OF HUMAN LOW-DENSITY LIPOPROTEINS OXIDATION BY Hibiscus radiatus CUV. CALYCES EXTRACT

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Hernawan Hernawan

2010-06-01

Full Text Available Hibiscus radiatus Cuv calyces extracts rich in polyphenols was screened for their potential to inhibit oxidation of human low-density lipoproteins-cholesterol (LDL-C in vitro. The inhibition of LDL-C oxidation (antioxidant activity was determined by measuring the formation of conjugated dienes and thiobarbituric acid reagent substances (TBARS. LDL-C oxidation was carried out in the presence of H. radiatus Cuv calyces extract (20 and 50 μM. CuSO4 (10 μM was used as the oxidation initiator and  butylated hydroxytoluene (BHT at 50 μM was used as standard antioxidant. The protective effect of H. radiatus Cuv. calyces extract toward human low-density lipoproteins, complex lipid system was  demonstrated by significant increase lag time (> 103 min, diminished of the propagation rate (44 %, and diminution of conjugated dienes formation 59.42 % (50 μM compared to control.   Keywords: antioxidant, conjugated dienes, Hibiscus radiatus Cuv, low-density lipoproteins-cholesterol

Antioxidant properties of a radical-scavenging peptide purified from enzymatically prepared fish skin gelatin hydrolysate.

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Mendis, Eresha; Rajapakse, Niranjan; Kim, Se-Kwon

2005-02-09

Hoki (Johnius belengerii) skin gelatin was hydrolyzed with three commercial enzymes to identify radical-scavenging potencies of derived peptides. Peptides derived from tryptic hydrolysate exhibited the highest scavenging activities on superoxide, carbon-centered 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals assessed by ESR spectroscopy. Following consecutive chromatographic separations of tryptic hydroolysate, the peptide sequence His-Gly-Pro-Leu-Gly-Pro-Leu (797 Da) acted as a strong radical scavenger under studied conditions. Further, this peptide could act as an antioxidant against linoleic acid peroxidation and the activity was closer to the highly active synthetic antioxidant butylated hydroxytoluene (BHT). In addition, antioxidative enzyme levels in cultured human hepatoma cells were increased in the presence of this peptide and it was presumed to be the peptide involved in maintaining the redox balance in the cell environment. Present data indicate that free-radical-scavenging activities of hoki skin gelatin peptides substantially contribute to their antioxidant properties measured in different oxidative systems.

Addition of anacardic acid as antioxidants in broiler chicken mortadella

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Virgínia Kelly Gonçalves ABREU

2015-09-01

Full Text Available AbstractThe effect of anacardic acid on lipid stability and coloration of chicken mortadella was investigated. Antioxidants were added to chicken mortadellas, according to the treatments: no added antioxidant, 100 ppm butylated hydroxytoluene and 50, 100, 150 and 200 ppm anacardic acid. The mortadellas were stored for 90 days at 4 °C, and the analysis of lipid oxidation and color were performed. For TBARS, there was linear reduction with increased anacardic acid. According to the means test, 200 ppm anacardic acid provided the lower TBARS values. The redness decreased during storage, and, as reported by the means test, mortadella containing 200 ppm anacardic acid had lower values. The lightness of mortadellas decreased during storage. Also in accordance with the means test, mortadellas containing antioxidants had same lightness than control. The yellowness of mortadellas increased during storage. Thus, the anacardic acid is a potential natural antioxidant that could be included in chicken mortadella formulations before cooking.

Stabilisation of phytosterols by natural and synthetic antioxidants in high temperature conditions.

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Kmiecik, Dominik; Korczak, Józef; Rudzińska, Magdalena; Gramza-Michałowska, Anna; Hęś, Marzanna; Kobus-Cisowska, Joanna

2015-04-15

The aim of the study was to assess the potential applicability of natural antioxidants in the stabilisation of phytosterols. A mixture of β-sitosterol and campesterol was incorporated into triacylglycerols (TAGs). The following antioxidants were added to the prepared matrix: green tea extract, rosemary extract, a mix of tocopherols from rapeseed oil, a mix of synthetic tocopherols, phenolic compounds extracted from rapeseed meal, sinapic acid and butylated hydroxytoluene (BHT). Samples were heated at a temperature of 180 °C for 4 h. After the completion of heating, the losses of phytosterols were analysed, as well as the contents of β-sitosterol and campesterol oxidation products. The total content of phytosterol oxidation products in samples ranged from 96.69 to 268.35 μg/g of oil. The effectiveness of antioxidants decreased in the following order: phenolic compounds from rapeseed meal>rosemary extract>mix of tocopherols from rapeseed oil>mix of synthetic tocopherols>green tea extract>sinapic acid>BHT. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preparation of organogel with tea polyphenols complex for enhancing the antioxidation properties of edible oil.

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Shi, Rong; Zhang, Qiuyue; Vriesekoop, Frank; Yuan, Qipeng; Liang, Hao

2014-08-20

Food-grade organogels are semisolid systems with immobilized liquid edible oil in a three-dimensional network of self-assembled gelators, and they are supposed to have a broad range of potential applications in food industries. In this work, an edible organogel with tea polyphenols was developed, which possesses a highly effective antioxidative function. To enhance the dispersibility of the tea polyphenols in the oil phase, a solid lipid-surfactant-tea polyphenols complex (organogel complex) was first prepared according to a novel method. Then, a food-grade organogel was prepared by mixing this organogel complex with fresh peanut oil. Compared with adding free tea polyphenols, the organogel complex could be more homogeneously distributed in the prepared organogel system, especially under heating condition. Furthermore, the organogel loading of tea polyphenols performed a 2.5-fold higher antioxidation compared with other chemically synthesized antioxidants (butylated hydroxytoluene and propyl gallate) by evaluating the peroxide value of the fresh peanut oil based organogel in accelerated oxidation conditions.

Biological and Phytopharmacological Descriptions of Litchi Chinensis.

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Kilari, Eswar Kumar; Putta, Swathi

2016-01-01

Plants remain a vital source of drugs and at present, much emphasis is given to nutraceuticals. Herbal medicines have been the basis of treatment and cure for various diseases and physiological conditions in the traditional methods practiced such as ayurveda and homeopathy. Litchi chinensis belongs to the Sapindaceae family and is well-known in the Indian traditional system for its traditional uses. The parts of the plant used are leaves, flowers, fruits, seed, pulp, and pericarp. All parts of the plant are rich sources of phytochemicals--epicatechin; procyanidin A2 and procyanidin B2; leucocyanidin; cyanidin glycoside, malvidin glycoside, and saponins; butylated hydroxytoluene; isolariciresinol; kaempferol; rutin; and stigmasterol. In the present review, we explore the lychee's description, traditional medicinal uses, and phytoconstituents, and investigate the pharmacological activities in various parts of the lychee to show its importance in ethanopharmacology. This is so that this review can serve as a ready-to-use material for further research on the plant.

Chemical composition and antioxidant activity of essential oil from leaves and rhizomes of Curcuma angustifolia Roxb.

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Jena, Sudipta; Ray, Asit; Banerjee, Anwesha; Sahoo, Ambika; Nasim, Noohi; Sahoo, Suprava; Kar, Basudeba; Patnaik, Jeetendranath; Panda, Pratap Chandra; Nayak, Sanghamitra

2017-09-01

The essential oil extracted from rhizome and leaf of Curcuma angustifolia Roxb. (Zingiberaceae) was characterised by gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis revealed the presence of 32 and 35 identified constituents, comprising 92.6% and 92% of total leaf and rhizome oil, respectively. Curzerenone (33.2%), 14-hydroxy-δ-cadinene (18.6%) and γ-eudesmol acetate (7.3%) were the main components in leaf oil. In rhizome oil, curzerenone (72.6%), camphor (3.3%) and germacrone (3.3%) were found to be the major constituents. Antioxidant capacities of oil were assessed by various methods, 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and reducing power ability (RPA). Based on the results, the leaf oil showed more antioxidant potential as compared to rhizome oil and reference standards (ascorbic acid and butylated hydroxytoluene (BHT)). Thus, the leaf essential oil of C. angustifolia can be used as an alternative source of natural antioxidant.

Composition and antioxidant capacity of the essential oil of leaves of Vitex megapotamica (Sprengel) Moldenke.

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de Brum, Thiele Faccim; Boligon, Aline Augusti; Frohlich, Janaína Kieling; Schwanz, Thiago Guilherme; Zadra, Marina; Piana, Mariana; Froeder, Amanda Luana Forbrig; Athayde, Margareth Linde

2013-04-01

This study is designed to examine the chemical composition and antioxidant activity of the essential oil of Vitex megapotamica. Gas chromatography-mass spectrometry analysis resulted in the detection of 27 components, representing 92.36% of the total oil composition. The main components in the oil were butylated hydroxytoluene (BHT) (34.17%), phytol (12.66%), α-caryophyllene (11.84%), δ-elemene (10.65%), β-caryophyllene (7.82%), γ-elemene (4.24%) and germacrene D (2.82%). The antioxidant activity of the oil was evaluated in terms of their free-radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl. The oil showed percentage inhibition of 35.62% and 75.25% at concentrations of 76 and 101.6 mg mL(-1), respectively. BHT (36.30%) was also determined by HPLC-DAD in the hexane fraction from the leaves. To the best of our knowledge, this is the first study of the composition and antioxidant activity of the essential oil of the species V. megapotamica.

Oxidation kinetics of common Kilka (Clupeonella cultiventris caspia) oil in presence of bene oils' unsaponifiable matter.

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Pazhouhanmehr, Samaneh; Farhoosh, Reza; Sharif, Ali; Esmaeilzadeh Kenari, Reza

2016-01-01

The oxidation mechanisms and kinetics of the purified common Kilka (Clupeonella cultiventris caspia) triacylglycerols (PKO) as affected by 1-1.5% (w/w) of unsaponifiable matters of bene kernel (UKO) and hull (UHO) oils were studied and compared with that of 100 mg/kg of butylated hydroxytoluene (BHT) and α-tocopherol in the Rancimat test at 50-70 °C. There were good correlations between the oxidative stability index (OSI) and time required to reach a 50%-increase in PV (t50). The frequency factor (A) and activation energy (Ea) were correlated well with the values of entropy and enthalpy, respectively. The values of free energy of activation (ΔG(++)) could describe the values of t50 or OSI well. Kinetic data indicated that the UKO with higher contents of tocopherols and tocotrienols, and terpenoid compounds was more effective than the UHO on the PKO stability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Caesalpinia decapetala Extracts as Inhibitors of Lipid Oxidation in Beef Patties

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Maria G. Gallego

2015-07-01

Full Text Available In this study we investigated the effects of Caesalpinia decapetala (CD extracts on lipid oxidation in ground beef patties. Plant extracts and butylated hydroxytoluene (BHT were individually added to patties at both 0.1% and 0.5% (w/w concentrations. We assessed the antioxidant efficacy of CD by the ferric reducing antioxidant power (FRAP assay and evaluated their potential as natural antioxidants for meat preservation by thiobarbituric acid reactive substance (TBARS values, hexanal content, fatty acid composition and color parameters. These were tested periodically during 11 days of refrigerated storage. TBARS levels were significantly lower (p ≤ 0.05 in the samples containing plant extracts or BHT than in the non-treated control. In addition, the beef patties formulated with the selected plant extracts showed significantly (p ≤ 0.05 better color stability than those without antioxidants. These results indicate that edible plant extracts are promising sources of natural antioxidants and can potentially be used as functional preservatives in meat products.

Alkaline and Organosolv Lignins from Furfural Residue: Structural Features and Antioxidant Activity

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Xue-Fei Cao

2013-12-01

Full Text Available Furfural residue (FR, composed mainly of cellulose and lignin, is an industrial waste produced during furfural manufacture. In this study, dioxane, alkali, ethanol, alkali-ethanol, and alkaline hydrogen peroxide (AHP were used to extract lignins from FR. The structural features of these lignins obtained were characterized by sugar analysis, GPC, UV, FT-IR, and HSQC spectra. As compared to dioxane lignin (DL, other lignins showed lower molecular weights (Mw owing to the partial cleavage of the linkages between lignin units. Results from HSQC spectra revealed that β-O-4' and β-5' were still the major linkages of the FR lignin. Moreover, p-coumaric and ferulic acids were released and co-precipitated in the lignin preparations extracted with alkali and AHP, whereas part of the esters in DL were preserved during the dioxane extraction. Antioxidant activity investigation indicated that the antioxidant property of the alkali and alkali-ethanol lignins was higher than that of the commercial antioxidant, butylated hydroxytoluene.

Preliminary evidence of the role of hydrogen peroxide in the degradation of benzo[a]pyrene by a non-white rot fungus Fusarium solani

International Nuclear Information System (INIS)

Veignie, Etienne; Rafin, Catherine; Woisel, Patrice; Cazier, Fabrice

2004-01-01

In order to study the enzymatic mechanisms involved in the successive steps of BaP degradation by a Deuteromycete fungus Fusarium solani, we developed an indirect approach by using inhibitors of enzymes. We used either specific inhibitors of peroxidases (i.e. salicylhydroxamic acid) and of cytochrome P-450 (i.e. piperonyl butoxyde) or inhibitors of both enzymes (i.e. potassium cyanide). Surprisingly, no expected decrease of BaP degradation was observed with most inhibitors tested. On the contrary, more BaP was degraded. Only butylated hydroxytoluene, which acts as a free radical scavenger, inhibited BaP degradation. The inhibition of these enzymes, which use H 2 O 2 as a cosubstrat, might have resulted in an increase of hydrogen peroxide availability in the fungal cultures. This enhancement could induce formation of reactive oxygen species (ROS) which might be the agents that initiate benzo[a]pyrene oxidation. This study proposed a hypothetic alternative metabolic pathway involved in PAH metabolism by Fusarium solani. - An alternative metabolic pathway was demonstrated

Free radical-scavenging capacity, antioxidant activity and phenolic content of Pouzolzia zeylanica

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PEIYUAN LI

2011-05-01

Full Text Available Pouzolzia zeylanica was extracted with different solvents (acetone, ethyl acetate and petroleum ether, using different protocols (cold-extraction and Soxhlet extraction. To evaluate the antiradical and antioxidant abilities of the extracts, four in vitro test systems were employed, i.e., DPPH, ABTS and hydroxyl radical scavenging assays and a reducing power assay. All extracts exhibited outstanding antioxidant activities that were superior to that of butylated hydroxytoluene. The ethyl acetate extracts exhibited the most significant antioxidant activities, and cold-extraction under stirring seemed to be the more efficacious method for acquiring the predominant antioxidants. Furthermore, the antioxidant activities and total phenolic (TP content of different extracts followed the same order, i.e., there is a good correlation between antioxidant activities and TP content. The results showed that these extracts, especially the ethyl acetate extracts, could be considered as natural antioxidants and may be useful for curing diseases arising from oxidative deterioration.

Trichomes and chemical composition of the volatile oil of Trichogonia cinerea (Gardner) R. M. King & H. Rob. (Eupatorieae, Asteraceae).

Science.gov (United States)

Fernandes, Yanne S; Trindade, Luma M P; Rezende, Maria Helena; Paula, José R; Gonçalves, Letícia A

2016-03-01

Trichogonia cinerea is endemic to Brazil and occurs in areas of cerrado and campo rupestre. In this study, we characterized the glandular and non-glandular trichomes on the aerial parts of this species, determined the principal events in the development of the former, and identified the main constituents of the volatile oil produced in its aerial organs. Fully expanded leaves, internodes, florets, involucral bracts, and stem apices were used for the characterization of trichomes. Leaves, internodes, florets, and involucral bracts were examined by light microscopy and scanning electron microscopy, whereas stem apices were examined only by light microscopy. Branches in the reproductive phase were used for the extraction and determination of the composition of the volatile oil. The species has three types of glandular trichomes, biseriate vesicular, biseriate pedunculate, and multicellular uniseriate, which secrete volatile oils and phenolic compounds. The major components identified in the volatile oil were 3,5-muuroladiene (39.56%) and butylated hydroxytoluene (13.07%).

Antioxidant activities of ginger extract and its constituents toward lipids.

Science.gov (United States)

Si, Wenhui; Chen, Yan Ping; Zhang, Jianhao; Chen, Zhen-Yu; Chung, Hau Yin

2018-01-15

Lipid oxidation-a major cause of food product deterioration-necessitates the use of food additives to inhibit food oxidation. Ginger extract (GE) has been reported to possess antioxidant properties. However, components isolated from ginger have been rarely reported to inhibit fat oxidation. Herein, antioxidant properties of GE and four pure components derived from it (6-gingerol, 8-gingerol, 10-gingerol, and 6-shogaol) were examined and their properties were compared to those of butylated hydroxytoluene. GE and the constituent components exhibited antioxidant properties that might be attributed to their hydroxyl groups and suitable solubilizing side chains. 6-Shogaol and 10-gingerol exhibited higher activity at 60°C than 6-gingerol and 8-gingerol. Low antioxidant activity was detected at high temperatures (120/180°C). Overall, GE displayed the strongest dose-dependent antioxidant properties, especially at high temperatures, thereby demonstrating that GE can be employed as a natural antioxidant in lipid-containing processed foods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermochemical studies on two alkyl-bulky substituted xanthene derivatives: 9,9-dimethylxanthene and 2,7-di-tert-butyl-9,9-dimethylxanthene

International Nuclear Information System (INIS)

Freitas, Vera L.S.; Gomes, José R.B.; Ribeiro da Silva, Maria D.M.C.

2017-01-01

Highlights: • Energetic characterization of two alkyl-bulky substituted xanthene derivatives. • Massic energies of combustion of xanthene derivatives. • Enthalpies of sublimation determined by vacuum drop microcalorimetry technique. • Temperature-vapour pressure dependence by mass-loss Knudsen effusion method. • Gas-phase enthalpies of formation of alkyl xanthene derivatives. - Abstract: Thermodynamic properties of 9,9-dimethylxanthene and 2,7-di-tert-butyl-9,9-dimethylxanthene for the condensed and gas states were derived from experimental and computational studies. Static-bomb combustion calorimetry, vacuum drop microcalorimetry and the Knudsen effusion techniques were used. Computational calculations of the enthalpies of hypothetical reactions in the gaseous phase, using the G3(MP2)//B3LYP composite method, were performed for the two xanthene derivatives. Natural bond orbital (NBO) calculations were also performed to ascertain the structure and reactivity of these compounds. The energetic effects caused by replacing hydrogen atoms in the xanthene moiety by methyl and tert-butyl groups yielding 9,9-dimethylxanthene and 2,7-di-tert-butyl-9,9-dimethylxanthene species were determined from direct comparison of their standard (p o = 0.1 MPa) molar enthalpies of formation in the gaseous phase, at T = 298.15 K.

Voltammetric Determination of Nitro Derivative of Synthetic Antioxidant 2,6-di-tert-butyl-4-methyl-phenol

Czech Academy of Sciences Publication Activity Database

Chýlková, J.; Machalický, O.; Tomášková, M.; Šelešovská, R.; Navrátil, Tomáš

2016-01-01

Roč. 49, č. 1 (2016), s. 92-106 ISSN 0003-2719 R&D Projects: GA ČR(CZ) GAP208/12/1645 Institutional support: RVO:61388955 Keywords : 2,6-di-tert-butyl-4-methyl-phenol * handing drop mercury electrode * nitration Subject RIV: CG - Electrochemistry Impact factor: 1.150, year: 2016

In situ NMR and modeling studies of nitroxide mediated copolymerization of styrene and n-butyl acrylate

NARCIS (Netherlands)

Hlalele, L.; Klumperman, L.

2011-01-01

The combination of in situ1H NMR and in situ31P NMR was used to study the nitroxide mediated copolymerization of styrene and n-butyl acrylate. The alkoxyamine MAMA-DEPN was employed to initiate and mediate the copolymerization. The nature of the ultimate/terminal monomer units of dormant polymer

Potential Impact of Seasonal Malaria Chemoprevention on the Acquisition of Antibodies Against Glutamate-Rich Protein and Apical Membrane Antigen 1 in Children Living in Southern Senegal

DEFF Research Database (Denmark)

Ndiaye, Magatte; Sylla, Khadime; Sow, Doudou

2015-01-01

Seasonal malaria chemoprevention (SMC) is defined as the intermittent administration of full treatment courses of an antimalarial drug to children during the peak of malaria transmission season with the aim of preventing malaria-associated mortality and morbidity. SMC using sulfadoxine-pyrimetham......Seasonal malaria chemoprevention (SMC) is defined as the intermittent administration of full treatment courses of an antimalarial drug to children during the peak of malaria transmission season with the aim of preventing malaria-associated mortality and morbidity. SMC using sulfadoxine......-pyrimethamine (SP) combined with amodiaquine (AQ) is a promising strategy to control malaria morbidity in areas of highly seasonal malaria transmission. However, a concern is whether SMC can delay the natural acquisition of immunity toward malaria parasites in areas with intense SMC delivery. To investigate this......, total IgG antibody (Ab) responses to Plasmodium falciparum antigens glutamate-rich protein R0 (GLURP-R0) and apical membrane antigen 1 (AMA-1) were measured by enzyme-linked immunosorbent assay in Senegalese children under the age of 10 years in 2010 living in Saraya and Velingara districts (with SMC...

Interaction of butylated hydroxyanisole with mitochondrial oxidative phosphorylation.

Science.gov (United States)

Fusi, F; Sgaragli, G; Murphy, M P

1992-03-17

The antioxidant, butylated hydroxyanisole (BHA), has a number of effects on mitochondrial oxidative phosphorylation. In this study we apply the novel approach developed by Brand (Brand MD, Biochim Biophys Acta 1018: 128-133, 1990) to investigate the site of action of BHA on oxidative phosphorylation in rat liver mitochondria. Using this approach we show that BHA increases the proton leak through the mitochondrial inner membrane and that it also inhibits the delta p (proton motive force across the mitochondrial inner membrane) generating system, but has no effect on the phosphorylation system. This demonstrates that compounds having pleiotypic effects on mitochondrial oxidative phosphorylation in vitro can be analysed and their many effects distinguished. This approach is of general use in analysing many other compounds of pharmacological interest which interact with mitochondria. The implications of these results for the mechanism of interaction of BHA with mitochondrial oxidative phosphorylation are discussed.

Synthesis of 1-/sup 11/C-labelled ethyl, propyl, butyl and isobutyl iodides and examples of alkylation reactions

Energy Technology Data Exchange (ETDEWEB)

Laangstroem, B.; Antoni, G.; Gullberg, P.; Halldin, C.; Naagren, K.; Rimland, A.; Svaerd, H.

1986-01-01

New /sup 11/C-labelled precursors (1-/sup 11/C)ethyl,(1-/sup 11/C)propyl, (1-/sup 11/C)butyl, and (1-/sup 11/C)isobutyl iodides have been prepared by a 3-step reaction route using a one-pot system. The labelled iodides were obtained in 20-55% radiochemical yields and 65-95% radiochemical purities, with a total time for synthesis of the order of 10-14 min. The labelled iodides have been used in alkylation reactions with nitrogen, oxygen and carbon nucleophiles. The nitrogen alkylation reactions are exemplified by the synthesis of the analgetics N-(1-/sup 11/C-ethyl)iodocaine and N-(1-/sup 11/C-butyl) bupivacaine. The synthesis of 3-nitrophenyl(1-/sup 11/C)propyl ether is also presented in this paper as an example of an oxygen alkylation.

Chemopreventive potential of β-Sitosterol in experimental colon cancer model - an In vitro and In vivo study

Directory of Open Access Journals (Sweden)

Paulraj Gabriel M

2010-06-01

Full Text Available Abstract Background Asclepias curassavica Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of β-sitosterol isolated from A. curassavica in colon cancer, using in vitro and in vivo models. Methods The active molecule was isolated, based upon bioassay guided fractionation, and identified as β-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of β-catenin and proliferating cell nuclear antigen (PCNA in human colon cancer cell lines (COLO 320 DM. The chemopreventive potential of β-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w. into male Wistar rats and supplementing this with β-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w. Results β-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 266.2 μM, induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of β-catenin and PCNA antigens in human colon cancer cells. β-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. Conclusion We found doses of 10-20 mg/kg b.w. β-sitosterol to be effective for future in vivo studies. β-sitosterol had chemopreventive potential by virtue of its radical quenching ability in vitro, with minimal toxicity to normal cells. It also attenuated β-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis.

Chemopreventive potential of β-Sitosterol in experimental colon cancer model - an In vitro and In vivo study

Science.gov (United States)

2010-01-01

Background Asclepias curassavica Linn. is a traditional medicinal plant used by tribal people in the western ghats, India, to treat piles, gonorrhoea, roundworm infestation and abdominal tumours. We have determined the protective effect of β-sitosterol isolated from A. curassavica in colon cancer, using in vitro and in vivo models. Methods The active molecule was isolated, based upon bioassay guided fractionation, and identified as β-sitosterol on spectral evidence. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of β-catenin and proliferating cell nuclear antigen (PCNA) in human colon cancer cell lines (COLO 320 DM). The chemopreventive potential of β-sitosterol in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w.) into male Wistar rats and supplementing this with β-sitosterol throughout the experimental period of 16 weeks at 5, 10, and 20 mg/kg b.w. Results β-sitosterol induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 266.2 μM), induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of β-catenin and PCNA antigens in human colon cancer cells. β-sitosterol supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. Conclusion We found doses of 10-20 mg/kg b.w. β-sitosterol to be effective for future in vivo studies. β-sitosterol had chemopreventive potential by virtue of its radical quenching ability in vitro, with minimal toxicity to normal cells. It also attenuated β-catenin and PCNA expression, making it a potential anticancer drug for colon carcinogenesis. PMID:20525330

Wet-Oxidation of Spent Organic Waste Tri-butyl Phosphate/Diluents

International Nuclear Information System (INIS)

El-Dessouky, M.I.; Abed El-Aziz, M.M.; El-Mossalamy, E.H.; Aly, H.F.

1999-01-01

Tri-Butyl Phosphate was used in reprocessing of spent nuclear fuel in the purex process. The amount of uranium retained in the organic phase depends on the type of TBP/Diluent. Destruction of spent TBP is of high interest in waste management. In the present work, oxidative degradation of TBP diluted with kerosene, carbon tetrachloride, benzene and toluene using potassium permanganate as oxidant was carried out to produce stable inorganic dry particle residue which is then immobilized in different matrices. The different factors affecting the destruction of spent waste was investigated. The up take and decontamination factor for both 152 and 154 Eu and 181 Hf and the analysis of the final product have been studied

Chemoprevention of colon carcinogenesis by polyethylene glycol: suppression of epithelial proliferation via modulation of SNAIL/beta-catenin signaling.

Science.gov (United States)

Roy, Hemant K; Kunte, Dhananjay P; Koetsier, Jennifer L; Hart, John; Kim, Young L; Liu, Yang; Bissonnette, Marc; Goldberg, Michael; Backman, Vadim; Wali, Ramesh K

2006-08-01

Polyethylene glycol (PEG) is one of the most potent chemopreventive agents against colorectal cancer; however, the mechanisms remain largely unexplored. In this study, we assessed the ability of PEG to target cyclin D1-beta-catenin-mediated hyperproliferation in the azoxymethane-treated rat model and the human colorectal cancer cell line, HT-29. Azoxymethane-treated rats were randomized to AIN-76A diet alone or supplemented with 5% PEG-8000. After 30 weeks, animals were euthanized and biopsies of aberrant crypt foci and uninvolved crypts were subjected to immunohistochemical and immunoblot analyses. PEG markedly suppressed both early and late markers of azoxymethane-induced colon carcinogenesis (fractal dimension by 80%, aberrant crypt foci by 64%, and tumors by 74%). In both azoxymethane-treated rats and HT-29 cells treated with 5% PEG-3350 for 24 hours, PEG decreased proliferation (45% and 52%, respectively) and cyclin D1 (78% and 56%, respectively). Because beta-catenin is the major regulator of cyclin D1 in colorectal cancer, we used the T-cell factor (Tcf)-TOPFLASH reporter assay to show that PEG markedly inhibited beta-catenin transcriptional activity. PEG did not alter total beta-catenin expression but rather its nuclear localization, leading us to assess E-cadherin expression (a major determinant of beta-catenin subcellular localization), which was increased by 73% and 71% in the azoxymethane-rat and HT-29 cells, respectively. We therefore investigated the effect of PEG treatment on levels of the negative regulator of E-cadherin, SNAIL, and observed a 50% and 75% decrease, respectively. In conclusion, we show, for the first time, a molecular mechanism through which PEG imparts its antiproliferative and hence profound chemopreventive effect.

Contribution to the study of uranyl salts in butyl phosphate solutions; Contribution a l'etude des solutions de sels d'uranyle dans les phosphates butyliques

Energy Technology Data Exchange (ETDEWEB)

Coulon, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1965-06-01

A spectroscopic study in the normal infrared region and involving the following associations: tri-alkyl phosphates (tri-butyl, tri-ethyl, tri-methyl), uranyl salts (nitrate, chloride, acetate) has confirmed the existence of an interaction between the phosphoryl group and the uranium atom, as shown by a movement of absorption band for the valency P = 0 from {approx} 1270 cm{sup -1} to {approx} 1180 cm{sup -1}. A study of the preparation, analysis and spectroscopy of the solids obtained by the precipitation of uranyl salts by acid butyl phosphates has been carried out. By infrared spectrophotometry it has been shown that the tri-butyl and di-butyl phosphates are associated in non-polar diluents even before the uranium is introduced. The extraction of uranyl salts from acid aqueous solutions by a diluted mixture of tri-butyl and di-butyl phosphates proceeds by different mechanisms according to the nature of the ion (nitrate or chloride). (author) [French] Une etude spectroscopique dans l'infrarouge moyen portant sur les associations: - phosphates trialcoyliques (tributylique - triethylique - trimethylique) - sels d'uranyle (nitrate, chlorure, acetate) a confirme l'existence d'une interaction entre le groupement phosphoryle et l'atome d'uranium, se manifestant par un deplacement de la bande d'absorption de la vibration de valence P = 0 de {approx} 1270 cm{sup -1} a {approx} 1180 cm{sup -1}. Une etude preparative, analytique et spectroscopique des solides obtenus par precipitation de sels d'uranyle par les phosphates butyliques acides a ete effectuee. La spectrophotomerie infrarouge met en evidence l'association, anterieure a toute introduction d'uranium, des phosphates tributylique et dibutylique dans des diluants non polaires. L'extraction de sels d'uranyle, d'une solution aqueuse acide par un melange dilue de phosphates tributylique et dibutylique, s'effectue suivant des processus differents a la

Developmental and testicular toxicity of butyl benzyl phthalate in the rat and the impact of study design

NARCIS (Netherlands)

Piersma AH; Verhoef A; Dormans JAMA; Elvers LH; Valk V de; Biesebeek JD te; Pieters MN; Slob W; LEO

1999-01-01

The developmental toxicity of butyl benzyl phthalate was investigated in the rat in an alternative study design using ten treatment groups. The effect of exposure period was studied, and a comparison of reaction to treatment in pregnant versus non-pregnant females was made. The classical data