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Sample records for alkaloids total synthesis

  1. Total Synthesis of Securinega Alkaloids

    Institute of Scientific and Technical Information of China (English)

    T. Honda

    2005-01-01

    @@ 1Introduction Naturally occurring Securinega alkaloids (1-4) (Fig. 1)[1], with their wide range of structural and stereochemical features, continue to provide challenging synthetic targets, since these alkaloids exhibit attractive biological activities. Securinine (1), isolated from Securinega suffruticosa [2], was structurally determined to contain an indolizidine skeleton with an azabicyclo[3.2.1 ]octane system together with an α, β-unsaturated γ-lactone ring. This alkaloid has been clinically used in Russia as a CNS stimulating drug[3], and has been shown to act as a stereospecific antagonist at the GABA binding site of the GABAA-receptor complex[4].Viroallosecurinine (2), a diastereoisomeric alkaloid of securinine, was also isolated from the leaves of Securinega virosa[5] as a cytotoxic alkaloid exhibiting a MIC of 0.48 μg/mL for Ps. aeruginosa and Staph.aureus[6]. This alkaloid is recognized to be bactericidal since the yields of MIC/MBC were less than 1[7].

  2. Total synthesis of the indolizidine alkaloid tashiromine

    Directory of Open Access Journals (Sweden)

    McElhinney Alison D

    2008-01-01

    Full Text Available Abstract Background Tashiromine 1 is a naturally occurring indolizidine alkaloid. It has been the subject of thirteen successful total syntheses to date. Our own approach centres on the stereoselective construction of the indolizidine core by capture of an electrophilic acyliminium species by a pendant allylsilane. The key cyclisation precursor is constructed using olefin cross-metathesis chemistry, which has the potential to facilitate both racemic and asymmetric approaches, depending upon the choice of the allylsilane metathesis partner. Results The use of the allyltrimethylsilane cross-metathesis approach enables the rapid construction of the key cyclisation precursor 3 (3 steps from commercial materials, which undergoes acid-induced cyclisation to give the desired bicyclic indolizidine skeleton as a 96:4 mixture of diastereomers. Simple functional group interconversions allowed the completion of the total synthesis of racemic tashiromine in six steps (19% overall yield. Three chiral α-alkoxyallylsilanes (12,14 and 15 were prepared in enantioenriched form and their cross-metathesis reactions studied as part of a putative asymmetric approach to tashiromine. In the event, α-hydroxysilane 12 underwent isomerisation under the reaction conditions to acylsilane 17, while silanes 14 and 15 were unreactive towards metathesis. Conclusion A concise, stereoselective total synthesis of racemic tashiromine has been developed. Attempts to translate this into an asymmetric synthesis have thus far been unsuccessful.

  3. Total Synthesis of the Zoanthamine Alkaloid

    Institute of Scientific and Technical Information of China (English)

    M. Miyashita

    2005-01-01

    @@ 1Introduction The zoanthamine alkaloids, a type of heptacyclic marine alkaloid isolated from colonial zoanthids of the genus Zoanthus sp., have attracted much attention from a wide area of science, because of their distinctive biological and pharmacological properties as well as their chemical structures with stereochemical complexity.Namely, norzoanthamine (1)[1] can suppress the loss of bone weight and strength in ovariectomized mice and has been considered a promising candidate for an antiosteoporotic drug[1], whereas zoanthamine (2)[2] has exhibited potent inhibitory activity toward phorbol myristate-induced inflammation in addition to powerful analgesic effects[2]. See Fig. 1.

  4. Total synthesis, biosynthesis and biological profiles of clavine alkaloids.

    Science.gov (United States)

    McCabe, Stephanie R; Wipf, Peter

    2016-07-01

    This review highlights noteworthy synthetic and biological aspects of the clavine subfamily of ergot alkaloids. Recent biosynthetic insights have laid the groundwork for a better understanding of the diverse biological pathways leading to these indole derivatives. Ergot alkaloids were among the first fungal-derived natural products identified, inspiring pharmaceutical applications in CNS disorders, migraine, infective diseases, and cancer. Pergolide, for example, is a semi-synthetic clavine alkaloid that has been used to treat Parkinson's disease. Synthetic activities have been particularly valuable to facilitate access to rare members of the Clavine family and empower medicinal chemistry research. Improved molecular target identification tools and a better understanding of signaling pathways can now be deployed to further extend the biological and medical utility of Clavine alkaloids. PMID:27215547

  5. Asymmetric Total Synthesis of the Indole Diterpene Alkaloid Paspaline.

    Science.gov (United States)

    Sharpe, Robert J; Johnson, Jeffrey S

    2015-10-01

    An enantioselective synthesis of the indole diterpenoid natural product paspaline is disclosed. Critical to this approach was the implementation of stereoselective desymmetrization reactions to assemble key stereocenters of the molecule. The design and execution of these tactics are described in detail, and a thorough analysis of observed outcomes is presented, ultimately providing the title compound in high stereopurity. This synthesis provides a novel template for preparing key stereocenters in this family of molecules, and the reactions developed en route to paspaline present a series of new synthetic disconnections in preparing steroidal natural products.

  6. Copper catalysed synthesis of indolylquinazolinone alkaloid bouchardatine

    Indian Academy of Sciences (India)

    Mayavan Viji; Rajagopal Nagarajan

    2014-07-01

    We describe the total synthesis of indolylquinazolinone alkaloid bouchardatine and some of the quinazolinone derivatives. The aerobic oxidation induced by copper(I) bromide, followed by Vilsmeier-Haack formylation gives the natural product bouchardatine alkaloid in good yield.

  7. First total synthesis of a guanidine alkaloid Nitensidine D using immobilized ionic liquid, microwaves and formamidinesulfinic acid

    Indian Academy of Sciences (India)

    Shallu; M L Sharma; Jasvinder Singh

    2014-11-01

    An efficient first total synthesis of a naturally occurring guanidine alkaloid, Nitensidine D isolated from ethanol extract of Pterogyne nitens has been described. Geraniol has been used as the starting material. N-alkylation of phthalimide has been achieved using immobilized ionic liquid and formamidinesulfinic acid acts as the guanylating reagent.

  8. Synthesis of the isoquinoline alkaloid, crispine C

    OpenAIRE

    Blair, A.; Stevenson, L; Sutherland, A

    2012-01-01

    The first total synthesis of the isoquinoline alkaloid, crispine C is described in seven steps using a Henry reaction and the Pictet–Gams variant of the Bischler–Napieralski reaction to effect the key transformations.

  9. A strategy for complex dimer formation when biomimicry fails: total synthesis of ten coccinellid alkaloids.

    Science.gov (United States)

    Sherwood, Trevor C; Trotta, Adam H; Snyder, Scott A

    2014-07-01

    Although dimeric natural products can often be synthesized in the laboratory by directly merging advanced monomers, these approaches sometimes fail, leading instead to non-natural architectures via incorrect unions. Such a situation arose during our studies of the coccinellid alkaloids, when attempts to directly dimerize Nature's presumed monomeric precursors in a putative biomimetic sequence afforded only a non-natural analogue through improper regiocontrol. Herein, we outline a unique strategy for dimer formation that obviates these difficulties, one which rapidly constructs the coccinellid dimers psylloborine A and isopsylloborine A through a terminating sequence of two reaction cascades that generate five bonds, five rings, and four stereocenters. In addition, a common synthetic intermediate is identified which allows for the rapid, asymmetric formal or complete total syntheses of eight monomeric members of the class. PMID:24959981

  10. Accessing the structural diversity of pyridone alkaloids: concise total synthesis of rac-citridone A.

    Science.gov (United States)

    Fotiadou, Anna D; Zografos, Alexandros L

    2011-09-01

    A unique route to the structural diversity of pyridone alkaloids is described based on the concept of a common synthetic strategy. Three different core structure analogues corresponding to akanthomycin, septoriamycin A, and citridone A have been prepared by using a highly selective and novel carbocyclization reaction.

  11. An efficient synthesis of loline alkaloids

    Science.gov (United States)

    Cakmak, Mesut; Mayer, Peter; Trauner, Dirk

    2011-07-01

    Loline (1) is a small alkaloid that, in spite of its simple-looking structure, has posed surprising challenges to synthetic chemists. It has been known for more than a century and has been the subject of extensive biological investigations, but only two total syntheses have been achieved to date. Here, we report an asymmetric total synthesis of loline that, with less then ten steps, is remarkably short. Our synthesis incorporates a Sharpless epoxidation, a Grubbs olefin metathesis and an unprecedented transannular aminobromination, which converts an eight-membered cyclic carbamate into a bromopyrrolizidine. The synthesis is marked by a high degree of chemo- and stereoselectivity and gives access to several members of the loline alkaloid family. It delivers sufficient material to support a programme aimed at studying the complex interactions between plants, fungi, insects and bacteria brokered by loline alkaloids.

  12. Synthesis of the Marine Pyrroloiminoquinone Alkaloids, Discorhabdins

    Directory of Open Access Journals (Sweden)

    Yasufumi Wada

    2010-04-01

    Full Text Available Manynatural products with biologically interesting structures have been isolated from marine animals and plants such as sponges, corals, worms, etc. Some of them are discorhabdin alkaloids. The discorhabdin alkaloids (discorhabdin A-X, isolated from marine sponges, have a unique structure with azacarbocyclic spirocyclohexanone and pyrroloiminoquinone units. Due to their prominent potent antitumor activity, discorhabdins have attracted considerable attention. Many studies have been reported toward the synthesis of discorhabdins. We have accomplished the first total synthesis of discorhabdin A (1, having the strongest activity in vitro among discorhabdins in 2003. In 2009, we have also accomplished the first total synthesis of prianosin B (2, having the 16,17-dehydropyrroloiminoquinone moiety, by a novel dehydrogenation reaction with a catalytic amount of NaN3. These synthetic studies, as well as syntheses of the discorhabdins by various chemists to-date, are reviewed here.

  13. Total synthesis of atropurpuran.

    Science.gov (United States)

    Gong, Jing; Chen, Huan; Liu, Xiao-Yu; Wang, Zhi-Xiu; Nie, Wei; Qin, Yong

    2016-01-01

    Due to their architectural intricacy and biological significance, the synthesis of polycyclic diterpenes and their biogenetically related alkaloids have been the subject of considerable interest over the last few decades, with progress including the impressive synthesis of several elusive targets. Despite tremendous efforts, conquering the unique structural types of this large natural product family remains a long-term challenge. The arcutane diterpenes and related alkaloids, bearing a congested tetracyclo[5.3.3.0(4,9).0(4,12)]tridecane unit, are included in these unsolved enigmas. Here we report a concise approach to the construction of the core structure of these molecules and the first total synthesis of (±)-atropurpuran. Pivotal features of the synthesis include an oxidative dearomatization/intramolecular Diels-Alder cycloaddition cascade, sequential aldol and ketyl-olefin cyclizations to assemble the highly caged framework, and a chemoselective and stereoselective reduction to install the requisite allylic hydroxyl group in the target molecule. PMID:27387707

  14. Total Synthesis of Millingtonine.

    Science.gov (United States)

    Brown, Patrick D; Lawrence, Andrew L

    2016-07-11

    Millingtonine is a glycosidic alkaloid that exists as a pair of pseudo-enantiomeric diastereomers. Consideration of the likely biosynthetic origins of this unusual natural product has resulted in the development of a seven-step total synthesis. Results from this synthetic work provide evidence in support of a proposed network of biosynthetic pathways that can account for the formation of several phenylethanoid natural products. PMID:27249628

  15. A stereodivergent strategy for the preparation of corynantheine and ipecac alkaloids, their epimers, and analogues: efficient total synthesis of (-)-dihydrocorynantheol, (-)-corynantheol, (-)-protoemetinol, (-)-corynantheal, (-)-protoemetine, and related natural and nonnatural compounds.

    Science.gov (United States)

    Zhang, Wei; Bah, Juho; Wohlfarth, Andreas; Franzén, Johan

    2011-12-01

    Here we present a general and common catalytic asymmetric strategy for the total and formal synthesis of a broad number of optically active natural products from the corynantheine and ipecac alkaloid families, for example, indolo[2,3-a]- and benzo[a]quinolizidines. Construction of the core alkaloid skeletons with the correct absolute and relative stereochemistry relies on an enantioselective and diastereodivergent one-pot cascade sequence followed by an additional diastereodivergent reaction step. This allows for enantio- and diastereoselective synthesis of three out of four possible epimers of the quinolizidine alkaloids that begin from common and easily accessible starting materials by using a common synthetic route. Focus has been made on excluding protecting groups and limiting isolation and purification of synthetic intermediates. This methodology is applied in the total synthesis of the natural products (-)-dihydrocorynantheol, (-)-hirsutinol, (-)-corynantheol, (-)-protometinol, (-)-dihydrocorynantheal, (-)-corynantheal, (-)-protoemetine, (-)-(15S)-hydroxydihydrocorynantheol, and an array of their nonnatural epimers. The potential of this strategy is also demonstrated in the synthesis of biologically interesting natural product analogues not accessible through synthetic elaboration of alkaloid precursors available from nature, for example, thieno[3,2-a]quinolizidine derivatives. We also report the formal synthesis of (+)-dihydrocorynantheine, (-)-emetine, (-)-cephaeline, (-)-tubulosine, and (-)-deoxytubulosine.

  16. Total Synthesis of (-)-Daphenylline.

    Science.gov (United States)

    Yamada, Ryosuke; Adachi, Yohei; Yokoshima, Satoshi; Fukuyama, Tohru

    2016-05-10

    Total synthesis of (-)-daphenylline, a hexacyclic Daphniphyllum alkaloid, was achieved. Construction of the tricyclic DEF ring system was initiated by asymmetric Negishi coupling followed by an intramolecular Friedel-Crafts reaction. Installation of a side chain onto the tricyclic core was carried out through Sonogashira coupling, stereocontrolled Claisen rearrangement by taking advantage of the characteristic conformation of the tricyclic DEF core, and the stereoselective alkylation of a lactone. After the introduction of a glycine unit, the ABC ring system was stereoselectively constructed through intramolecular cycloaddition of the cyclic azomethine ylide. PMID:27062676

  17. Total Synthesis and Biological Activity of Marine Alkaloid Eudistomins Y1–Y7 and Their Analogues

    Directory of Open Access Journals (Sweden)

    Tao Jiang

    2013-04-01

    Full Text Available Eudistomin Y class compounds are a series of β-carbolines which was originally isolated from a marine turnicate or ascidian near the South Korea Sea. These compounds contain bromo-substituted groups, which is one of the typical characters of marine natural products. We report herein the chemical synthesis and biological evaluation of seven new β-carboline-based metabolites, Eudistomins Y1–Y7, and their hydroxyl-methylated phenyl derivatives. Using bromo-substituted tryptamines and bromo-substituted phenylglyoxals as the key intermediates, Eudistomins Y1–Y7 and their derivatives were synthesized via the acid-catalyzed Pictet-Spengler reaction and fully characterized by 1H- and 13C-NMR and mass spectroscopy. Biological studies revealed that all of the compounds showed moderate growth inhibitory activity against breast carcinoma cell line MDA-231 with IC50 of 15–63 μM and the inhibitory activities of hydroxyl-methylated phenyl products were higher than that of the corresponding natural products Eudistomins Y1–Y7.

  18. Synthesis of the C(18) -norditerpenoid alkaloid neofinaconitine: a lesson in convergent synthesis planning.

    Science.gov (United States)

    Liu, Xiao-Yu; Chen, David Y-K

    2014-01-20

    Hexacyclic framework: The total synthesis of the complex C18 -norditerpenoid alkaloid neofinaconitine has been achieved by a convergent approach. This remarkable synthesis featured two Diels-Alder cycloadditions and subsequent Mannich-type N-acyliminium and radical cyclizations to establish the unique hexacyclic core structure of the target molecule.

  19. Unified Synthesis of 10-Oxygenated Lycopodium Alkaloids: Impact of C10-Stereochemistry on Reactivity.

    Science.gov (United States)

    Saha, Mrinmoy; Li, Xin; Collett, Nathan D; Carter, Rich G

    2016-07-15

    The pronounced impact of the C10 stereochemistry on the successful construction of a polycyclic Lycopodium alkaloid scaffold has been explored. A wide range of reaction conditions and functionality were investigated to control a keto sulfone Michael addition to construct the C7-C12 linkage. An unexpected, overriding impact of the C10 stereochemistry in stereoselectivity and reaction rate in the Michael addition was observed. Furthermore, divergent reactivity of a conformationally accelerated, intramolecular Mannich cyclization based on the C10 stereochemistry was discovered. The successful execution of this synthetic route resulted in the total synthesis of all three known 10-oxygenated Lycopodium alkaloids: 10-hydroxylycopodine, paniculine, and deacetylpaniculine. PMID:27353498

  20. Synthesis studies on the Melodinus alkaloid meloscine

    OpenAIRE

    Feldman, Ken S.; Antoline, Joshua F.

    2013-01-01

    The pentacyclic Melodinus alkaloid (±)-meloscine was synthesized in 19 chemical steps from 2-bromobenzaldehyde through a route featuring an allenyl azide cyclization cascade to deliver the core azabicyclo[3.3.0]octane substructure. Peripheral functionalization of this core included a Tollens-type aldol condensation to set the quaternary center at C(20) and a diastereoselective ring closing metathesis to forge the tetrahydropyridine ring.

  1. Total Synthesis of Naloxone

    Institute of Scientific and Technical Information of China (English)

    HU Wen-Xiang; WANG Jian-Ying; XU Ming

    2003-01-01

    @@ Naloxone (1) is one of the 14-hydroxyl substituted opium antagonists which are valuable medications for treat ment of opiate abuse, opiate overdose, and alcohol addiction. Here, the total synthesis of naloxone was described. We selected 2,6-dihydroxynaphalene (2) as the starting material.

  2. Total synthesis of teixobactin

    Science.gov (United States)

    Jin, Kang; Sam, Iek Hou; Po, Kathy Hiu Laam; Lin, Du'an; Ghazvini Zadeh, Ebrahim H.; Chen, Sheng; Yuan, Yu; Li, Xuechen

    2016-08-01

    To cope with the global bacterial multidrug resistance, scientific communities have devoted significant efforts to develop novel antibiotics, particularly those with new modes of actions. Teixobactin, recently isolated from uncultured bacteria, is considered as a promising first-in-class drug candidate for clinical development. Herein, we report its total synthesis by a highly convergent Ser ligation approach and this strategy allows us to prepare several analogues of the natural product.

  3. Total synthesis of teixobactin.

    Science.gov (United States)

    Jin, Kang; Sam, Iek Hou; Po, Kathy Hiu Laam; Lin, Du'an; Ghazvini Zadeh, Ebrahim H; Chen, Sheng; Yuan, Yu; Li, Xuechen

    2016-01-01

    To cope with the global bacterial multidrug resistance, scientific communities have devoted significant efforts to develop novel antibiotics, particularly those with new modes of actions. Teixobactin, recently isolated from uncultured bacteria, is considered as a promising first-in-class drug candidate for clinical development. Herein, we report its total synthesis by a highly convergent Ser ligation approach and this strategy allows us to prepare several analogues of the natural product. PMID:27484680

  4. Total synthesis of ochnaflavone

    OpenAIRE

    Monica M. Ndoile; van Heerden, Fanie R

    2013-01-01

    The first total syntheses of ochnaflavone, an asymmetric biflavone consisting of apigenin and luteolin moieties, and the permethyl ether of 2,3,2'',3''-tetrahydroochnaflavone have been achieved. The key steps in the synthesis of ochnaflavone were the formation of a diaryl ether and ring cyclization of an ether-linked dimeric chalcone to assemble the two flavone nuclei. Optimal experimental conditions for the oxidative cyclization to form ochnaflavone were established.

  5. Total synthesis of ochnaflavone

    Directory of Open Access Journals (Sweden)

    Monica M. Ndoile

    2013-07-01

    Full Text Available The first total syntheses of ochnaflavone, an asymmetric biflavone consisting of apigenin and luteolin moieties, and the permethyl ether of 2,3,2'',3''-tetrahydroochnaflavone have been achieved. The key steps in the synthesis of ochnaflavone were the formation of a diaryl ether and ring cyclization of an ether-linked dimeric chalcone to assemble the two flavone nuclei. Optimal experimental conditions for the oxidative cyclization to form ochnaflavone were established.

  6. Synthesis and Antimicrobial Characterization of Half-Calycanthaceous Alkaloid Derivatives.

    Science.gov (United States)

    Zheng, Shaojun; Zhou, Xinping; Xu, Shixun; Zhu, Rui; Bai, Hongjin; Zhang, Jiwen

    2016-01-01

    A total of 29 novel tetrahydropyrroloindol-based calycanthaceous alkaloid derivatives were synthesized from indole-3-acetonitrile in good yields. The synthesized compounds were evaluated against nine strains of bacteria and a wide range of plant pathogen fungi. Bioassay results revealed that majority of the compounds displayed similar or higher in vitro antimicrobial activities than the positive control. The biological activities also indicated that substituents at R₄ and R₅ significantly affect the activities. Notably, compound c4 was found to be most active among the tested calycanthaceous analogues and might be a novel potential leading compound for further development as an antifungal agent. The results could pave the way for further design and structural modification of calycanthaceous alkaloids as antimicrobial agents. PMID:27618003

  7. Biogenetically inspired synthesis and skeletal diversification of indole alkaloids.

    Science.gov (United States)

    Mizoguchi, Haruki; Oikawa, Hideaki; Oguri, Hiroki

    2014-01-01

    To access architecturally complex natural products, chemists usually devise a customized synthetic strategy for constructing a single target skeleton. In contrast, biosynthetic assembly lines often employ divergent intramolecular cyclizations of a polyunsaturated common intermediate to produce diverse arrays of scaffolds. With the aim of integrating such biogenetic strategies, we show the development of an artificial divergent assembly line generating unprecedented numbers of scaffold variations of terpenoid indole alkaloids. This approach not only allows practical access to multipotent intermediates, but also enables systematic diversification of skeletal, stereochemical and functional group properties without structural simplification of naturally occurring alkaloids. Three distinct modes of [4+2] cyclizations and two types of redox-mediated annulations provided divergent access to five skeletally distinct scaffolds involving iboga-, aspidosperma-, andranginine- and ngouniensine-type skeletons and a non-natural variant within six to nine steps from tryptamine. The efficiency of our approach was demonstrated by successful total syntheses of (±)-vincadifformine, (±)-andranginine and (-)-catharanthine.

  8. A convenient microwave-assisted synthesis of cinchona alkaloid-derived ligands

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An efficient synthesis of cinchona alkaloid-derived ligands based on solvent-free microwave-assisted reaction was described. The coupling of 1,4-dichlorophthalazine or 3,6-dichloropyridazine with quinine, cinchonine or cinchonidine provide bis- or mono-cinchona alkaloid-derived ligands in moderate to good yields (52-89%) within 15 rain under optimum microwave conditions.

  9. Enantioselective Total Synthesis of (-)-Alstoscholarisine A.

    Science.gov (United States)

    Liang, Xiao; Jiang, Shi-Zhi; Wei, Kun; Yang, Yu-Rong

    2016-03-01

    We report a concise and highly enantioselective total synthesis of (-)-alstoscholarisine A (1), a recently isolated monoterpenoid indole alkaloid that has significant bioactivity in promoting adult neuronal stem cells proliferation. A highly enantioselective (99% ee), intramolecular Ir-catalyzed Friedel-Crafts alkylation of indole 9 with a secondary allylic alcohol was utilized to establish the first stereogenic center upon which the other three contiguous chiral centers were readily set by a highly stereoselective tandem 1,4-addition and aldol reaction. The key tetrahydropyran was constructed through a hemiacetal reduction, and the final aminal bridge was forged by a one-pot reductive amination/cyclization. The conciseness of this approach was highlighted by building core bonds in each step with a minimalist protecting group strategy. PMID:26882407

  10. Studies on quantitative determination of total alkaloids and berberine in five origins of crude medicine "Sankezhen".

    Science.gov (United States)

    Li, Luyang; Long, Weifang; Wan, Xiangluan; Ding, Qi; Zhang, Fei; Wan, Dingrong

    2015-02-01

    The roots of Berberis plants are widely used as a traditional Chinese medicine called "Sankezhen", having the activities of antibacterial and anti-inflammatory, and the ingredients are alkaloids. This work aims to study and compare the total alkaloids and individual alkaloid (berberine) contents in roots and stems from five origins of Berberis plants (Berberis soulieana Schneid., B. henryana Schneid., B. triacanthophora Fedde, B. gagnepainii Schneid. and B. bergmanniae Schneid.) and provides some references for resource and quality evaluation of the medicine. Acid dye colorimetry and high-performance liquid chromatography were used in the determination. The results showed that the contents for the total alkaloids in root and stem samples were in the range of 1.60-4.72% and 0.76-2.70%, while those of the berberine were 0.70-2.92% and 0.23-1.07%. With higher contents of the total alkaloids and berberine, the roots of B. soulieana, B. gagnepainii and B. bergmanniae were good sources of "Sankezhen". Meanwhile, the contents were also high in stems of the three plants, indicating that the stems were likely to be alternative sources of "Sankezhen" after further research. As the results of precision, stability and recovery tests shown, the methods were simple, rapid and reliable, and provided valuable basis for quality evaluation and new resource investigation of "Sankezhen". PMID:25013028

  11. Synthesis of 1-Substituted Isoquinolines by Heterocyclization of TosMIC Derivatives: Total Synthesis of Cassiarin A.

    Science.gov (United States)

    Gutiérrez, Sara; Coppola, Anna; Sucunza, David; Burgos, Carolina; Vaquero, Juan J

    2016-07-15

    A new method for the synthesis of 1-substituted isoquinolines by a heterocyclization that involves α-benzyl TosMIC derivatives and different electrophiles has been developed. This methodology has been successfully applied to a total synthesis of cassiarin A, an alkaloid with potent antiplasmodial activity against Plasmodium falciparum. PMID:27351205

  12. Biocatalytic organic synthesis of optically pure (S)-scoulerine and berbine and benzylisoquinoline alkaloids.

    Science.gov (United States)

    Schrittwieser, Joerg H; Resch, Verena; Wallner, Silvia; Lienhart, Wolf-Dieter; Sattler, Johann H; Resch, Jasmin; Macheroux, Peter; Kroutil, Wolfgang

    2011-08-19

    A chemoenzymatic approach for the asymmetric total synthesis of the title compounds is described that employs an enantioselective oxidative C-C bond formation catalyzed by berberine bridge enzyme (BBE) in the asymmetric key step. This unique reaction yielded enantiomerically pure (R)-benzylisoquinoline derivatives and (S)-berbines such as the natural product (S)-scoulerine, a sedative and muscle relaxing agent. The racemic substrates rac-1 required for the biotransformation were prepared in 4-8 linear steps using either a Bischler-Napieralski cyclization or a C1-Cα alkylation approach. The chemoenzymatic synthesis was applied to the preparation of fourteen enantiomerically pure alkaloids, including the natural products (S)-scoulerine and (R)-reticuline, and gave overall yields of up to 20% over 5-9 linear steps.

  13. Biocatalytic Organic Synthesis of Optically Pure (S)-Scoulerine and Berbine and Benzylisoquinoline Alkaloids

    Science.gov (United States)

    2011-01-01

    A chemoenzymatic approach for the asymmetric total synthesis of the title compounds is described that employs an enantioselective oxidative C–C bond formation catalyzed by berberine bridge enzyme (BBE) in the asymmetric key step. This unique reaction yielded enantiomerically pure (R)-benzylisoquinoline derivatives and (S)-berbines such as the natural product (S)-scoulerine, a sedative and muscle relaxing agent. The racemic substrates rac-1 required for the biotransformation were prepared in 4–8 linear steps using either a Bischler–Napieralski cyclization or a C1–Cα alkylation approach. The chemoenzymatic synthesis was applied to the preparation of fourteen enantiomerically pure alkaloids, including the natural products (S)-scoulerine and (R)-reticuline, and gave overall yields of up to 20% over 5–9 linear steps. PMID:21739961

  14. Alstoscholarisines H-J, Indole Alkaloids from Alstonia scholaris: Structural Evaluation and Bioinspired Synthesis of Alstoscholarisine H.

    Science.gov (United States)

    Pan, Zhiqiang; Qin, Xu-Jie; Liu, Ya-Ping; Wu, Ting; Luo, Xiao-Dong; Xia, Chengfeng

    2016-02-19

    Alstoscholarisines H-J (1-3), new monoterpenoid indole alkaloids with an unprecedented skeleton created via the formation of a C-3/N-1 bond, were isolated from Alstonia scholaris. Their structures were established by extensive spectroscopic analyses and the assessment of single-crystal X-ray diffraction data. The total synthesis of alstoscholarisine H was achieved via the regioselective nucleophilic addition of pyridinium through a bioinspired iminium ion intermediate followed by Pictet-Spengler-like cyclization. PMID:26800290

  15. Concise total synthesis and structural revision of (+)-pestalazine B.

    Science.gov (United States)

    Pérez-Balado, Carlos; de Lera, Angel R

    2010-11-21

    A convergent synthesis of the proposed structure of (+)-pestalazine B has been achieved in 4 steps using the N-alkylation of an unprotected tryptophan diketopiperazine with a 3a-bromopyrrolidinoindoline as the key step. Although its structure was confirmed by X-ray analysis, the spectroscopic data did not match those of the natural product. The versatility of the methodology allowed the preparation of several diastereomers, and the database generated led to the proposal of an isomeric structure for the natural alkaloid where the d-leucine and d-phenylalanine residues exchanged positions, which was corroborated by total synthesis. PMID:20848034

  16. Diastereoselective Total Synthesis of (-)-Galiellalactone.

    Science.gov (United States)

    Kim, Taewoo; Han, Young Taek; An, Hongchan; Kim, Kyeojin; Lee, Jeeyeon; Suh, Young-Ger

    2015-12-18

    An enantioselective total synthesis of (-)-galiellalactone has been accomplished. The key features of the synthesis involve the highly stereoselective construction of the cis-trisubstituted cyclopentane intermediate by a Pd(0)-catalyzed cyclization, the stereospecific introduction of an angular hydroxyl group by Riley oxidation, and the efficient construction of the tricyclic system of (-)-galiellalactone via a combination of diastereoselective Hosomi-Sakurai crotylation and ring-closing metathesis (RCM). PMID:26544529

  17. Marine bromopyrrole alkaloids: synthesis and diverse medicinal applications.

    Science.gov (United States)

    Rane, Rajesh; Sahu, Niteshkumar; Shah, Chetan; Karpoormath, Rajshekhar

    2014-01-01

    Marine organisms have been found to be a very rich source of bioactive molecules. Among marine organisms, sponges have been proven to be excellent producers of secondary metabolites. More than 5,300 compounds have been isolated from sponges with around 200 new molecules reported each year. Bromopyrrole alkaloids constitute a family of exclusively marine alkaloids and represent a fascinating example of the large variety of compounds formed by marine sponges which exhibit different biological activities such as antifeedent, anti-biofilm, anticancer, antiinflammatory, antimicrobial, immunomodulatory, analgesic, antiserotonergic, antiangiogenic, antihistaminic, chitinase inhibitor and actimyosin ATPase activator. More than 140 derivatives with different structures and biological activities, have been isolated from more than 20 different sponges. Most of these alkaloids share a key building block, pyrrole-imidazole with oroidin being their underlying structural motif. In this review detailed account of isolation and medicinal application of marine bromopyrrole alkaloids and their synthetic derivatives are discussed. PMID:24359195

  18. First total synthesis of Boehmenan

    Indian Academy of Sciences (India)

    Yamu Xia; Xiaoli Dai; Haixin Liu; Chen Chai

    2014-05-01

    The first total synthesis of dilignan Boehmenan has been achieved. A biomimetic oxidative coupling of the ferulic acid methyl ester in the presence of silver oxide is the crucial step in the synthesis sequence, generating the dihydrobenzofuran skeleton. Hydroxyl group was protected with DHP and reducted with LiAlH4 to afford the intermediate diol. The diol was condensated with the derivative of ferulic acid, then removed the protecting groups, to get Boehmenan. Meanwhile, a study on the ring-opening reaction of the intermediate dihydrobenzofuran neolignan under base conditions was described.

  19. Simple Indolizidine and Quinolizidine Alkaloids.

    Science.gov (United States)

    Michael, Joseph P

    2016-01-01

    This review of simple indolizidine and quinolizidine alkaloids (i.e., those in which the parent bicyclic systems are in general not embedded in polycyclic arrays) is an update of the previous coverage in Volume 55 of this series (2001). The present survey covers the literature from mid-1999 to the end of 2013; and in addition to aspects of the isolation, characterization, and biological activity of the alkaloids, much emphasis is placed on their total synthesis. A brief introduction to the topic is followed by an overview of relevant alkaloids from fungal and microbial sources, among them slaframine, cyclizidine, Steptomyces metabolites, and the pantocins. The important iminosugar alkaloids lentiginosine, steviamine, swainsonine, castanospermine, and related hydroxyindolizidines are dealt with in the subsequent section. The fourth and fifth sections cover metabolites from terrestrial plants. Pertinent plant alkaloids bearing alkyl, functionalized alkyl or alkenyl substituents include dendroprimine, anibamine, simple alkaloids belonging to the genera Prosopis, Elaeocarpus, Lycopodium, and Poranthera, and bicyclic alkaloids of the lupin family. Plant alkaloids bearing aryl or heteroaryl substituents include ipalbidine and analogs, secophenanthroindolizidine and secophenanthroquinolizidine alkaloids (among them septicine, julandine, and analogs), ficuseptine, lasubines, and other simple quinolizidines of the Lythraceae, the simple furyl-substituted Nuphar alkaloids, and a mixed quinolizidine-quinazoline alkaloid. The penultimate section of the review deals with the sizable group of simple indolizidine and quinolizidine alkaloids isolated from, or detected in, ants, mites, and terrestrial amphibians, and includes an overview of the "dietary hypothesis" for the origin of the amphibian metabolites. The final section surveys relevant alkaloids from marine sources, and includes clathryimines and analogs, stellettamides, the clavepictines and pictamine, and bis

  20. Synthesis of bicyclic alkaloids from the iridoid antirrhinoside

    DEFF Research Database (Denmark)

    Frederiksen, Signe Maria

    The present thesis describes the isolation of the iridoid glucoside antirrhinoside from Antirrhinum majus, and the approaches made towards its transformation into analogues of biologically active compounds, with special interest in syntheses of bicyclic alkaloids.A synthetic piperidine monoterpene...... alkaloid was prepared from antirrhinoside by means of an enzymatic cleavage to afford the aglucone, followed by a double reductive amination with benzylamine hydrochloride and sodium cyanoborohydride. The resulting piperidine was modified by opening of the epoxide on the cyclopropane ring by azide...... strategy was therefore abandoned.A one-pot reaction involving ozonolysis and subsequent reduction of the 5,6-O-isopropylidene-2',3',4',6'-tetra-O-acetyl antirrhinoside yielded a diol, which was considered a potential intermediate in the preparation of enantiopure 3-azabicyclo[3.3.0]octane alkaloids...

  1. Pharmacological Evaluation of Total Alkaloids from Nux Vomica: Effect of Reducing Strychnine Contents

    Directory of Open Access Journals (Sweden)

    Jun Chen

    2014-04-01

    Full Text Available The aim of the study was to investigate the possibility of improving the therapeutic efficacy of the total alkaloid fraction (TAF extracted from processed nux vomica by reducing the strychnine contents. Most strychnine was removed from TAF to obtain the modified total alkaloid fraction (MTAF. The toxicity and pharmacokinetics of TAF and MTAF were further investigated and compared besides their antitumor, analgesic and anti-inflammatory activities. The results showed that the ratios of brucine to strychnine were 1:2.05 and 2.2:1 for TAF and MTAF, respectively, and the toxicity of TAF was about 3.17-fold higher than that of MTAF. Compared to brucine alone, the elimination of brucine was found to be inhibited by other alkaloids in TAF or MTAF except strychnine. Significantly increased pharmacological activities when administered by the oral route were obtained with MTAF in comparison to TAF and nux vomica powder (NVP. In summary, MTAF might replace NVP and TAF in the clinical application of Chinese medicine to obtain much higher efficacy.

  2. Design, synthesis and biological evaluation of Erythrina alkaloid analogues as neuronal nicotinic acetylcholine receptor antagonists

    DEFF Research Database (Denmark)

    Crestey, François; Jensen, Anders A.; Borch, Morten;

    2013-01-01

    The synthesis of a new series of Erythrina alkaloid analogues and their pharmacological characterization at various nicotine acetylcholine receptor (nAChR) subtypes are described. The compounds were designed to be simplified analogues of aromatic erythrinanes with the aim of obtaining subtype...

  3. Stereoselective Total Synthesis of Mycalamides

    Institute of Scientific and Technical Information of China (English)

    Masahiro Toyota

    2005-01-01

    @@ 1Introduction Mycalamides A (1a) and B (1b) are potent antiviral compounds from a New Zealand sponge of the genus Mycale. Apart from their antitumor property, mycalamide A (1a) exhibits immunosuppressive action by blocking T-cell activation in mice and is significantly more potent than FK-506 and cyclosporine A. Because of their intriguing biological activity, unique structures and scarce supply of these natural products, mycalamides A (1a) and B (1b) have attracted considerable attention as target molecules for total synthesis, and total, formal, or partial syntheses of this family of compounds have been reported[1,2].

  4. A Concise Total Synthesis of S-(+)-Tylophorine

    Institute of Scientific and Technical Information of China (English)

    JIN,Zhong; WANG,Qing-Min; LI,Hao; LIU,Yu-Xiu; LI,Shi-Pu; HUANG,Run-Qiu

    2004-01-01

    @@ Phenanthroindolizidine alkaloids, which exhibit extensively biological properties, are widely present at various plants of the Asclepiadaceae family.[1] The significantly biological importance of these natural products has attracted considerable synthetic efforts.[2] We herein report an efficiently asyinmetric synthesis of S-(+)-tylophorine (1), as a typically representative alkaloids.

  5. Synthesis and Biological Evaluation of Novel 3-Alkylpyridine Marine Alkaloid Analogs with Promising Anticancer Activity

    OpenAIRE

    Alessandra Mirtes Marques Neves Gonçalves; Aline Brito de Lima; Maria Cristina da Silva Barbosa; Luiz Fernando de Camargos; Júlia Teixeira Oliveira; Camila de Souza Barbosa; José Augusto Ferreira Perez Villar; André Carvalho Costa; Isabella Viana Gomes da Silva; Luciana Maria Silva; Fernando de Pilla Varotti; Fabio Vieira dos Santos; Gustavo Henrique Ribeiro Viana

    2014-01-01

    Cancer continues to be one of the most important health problems worldwide, and the identification of novel drugs and treatments to address this disease is urgent. During recent years, marine organisms have proven to be a promising source of new compounds with action against tumoral cell lines. Here, we describe the synthesis and anticancer activity of eight new 3-alkylpyridine alkaloid (3-APA) analogs in four steps and with good yields. The key step for the synthesis of these compounds is a ...

  6. Cu-Mediated Stille Reactions of Sterically Congested Fragments: Towards the Total Synthesis of Zoanthamine

    DEFF Research Database (Denmark)

    Nielsen, Thomas E.; Le Quement, Sebastian; Juhl, Martin;

    2005-01-01

    A study on the Stille reaction of alkenyl iodides and starmanes with structural resemblance to retrosynthetic fragments of a projected total synthesis of the marine alkaloid zoanthamine was carried out. A range of reaction conditions was examined, and a protocol developed by Corey utilizing exces...

  7. A concise synthesis of (R)-Bgugaine, a pyrrolidine alkaloid from Arisarum vulgare

    Digital Repository Service at National Institute of Oceanography (India)

    Majik, M.S.; Parameswaran, P.S; Tilve, S.G.

    concise synthesis of (R)-Bgugaine, a pyrrolidine alkaloid from arisarum vulgare Mahesh S. Majik a , P.S. Parameswaran b and Santosh G. Tilve a * a Department of Chemistry, Goa University, Taleigao Plateau, Goa 403 206, India b National Institute... and effective chiral catalysts. 2-4 There are a large number of studies concerning the development of new syntheses of these molecules. 5-7 (R)-Bgugaine (1) is a natural 2-alkyl pyrrolidine alkaloid, first isolated 8 in 1993 from the tubers...

  8. Sarpagine and Related Alkaloids.

    Science.gov (United States)

    Namjoshi, Ojas A; Cook, James M

    2016-01-01

    The sarpagine-related macroline and ajmaline alkaloids share a common biosynthetic origin, and bear important structural similarities, as expected. These indole alkaloids are widely dispersed in 25 plant genera, principally in the family Apocynaceae. Very diverse and interesting biological properties have been reported for this group of natural products. Isolation of new sarpagine-related alkaloids and the asymmetric synthesis of these structurally complex molecules are of paramount importance to the synthetic and medicinal chemists. A total of 115 newly isolated sarpagine-related macroline and ajmaline alkaloids, along with their physicochemical properties have been included in this chapter. A general and efficient strategy for the synthesis of these monomeric alkaloids, as well as bisindoles, has been presented, which involves application of the asymmetric Pictet-Spengler reaction (>98% ee) as a key step because of the ease of scale up of the tetracyclic template. Also included in this chapter are the syntheses of the sarpagine-related alkaloids, published since 2000. PMID:26827883

  9. The total synthesis of (-)-nitidasin.

    Science.gov (United States)

    Hog, Daniel T; Huber, Florian M E; Mayer, Peter; Trauner, Dirk

    2014-08-01

    Nitidasin is a pentacyclic sesterterpenoid with a rare 5-8-6-5 carbon skeleton that was isolated from the Peruvian folk medicine "Hercampuri". It belongs to a small class of sesterterpenoids that feature an isopropyl trans-hydrindane moiety fused to a variety of other ring systems. As a first installment of our general approach toward these natural products, we report the total synthesis of the title compound. Our stereoselective, convergent route involves the addition of a complex alkenyl lithium compound to a trans-hydrindanone, followed by chemoselective epoxidation, ring-closing olefin metathesis, and redox adjustment.

  10. Isolation, structure elucidation, and biomimetic total synthesis of versicolamide B and the isolation of antipodal (-)-stephacidin A and (+)-notoamide B from Aspergillus versicolor

    Science.gov (United States)

    A new prenylated indole alkaloid, versicolamide B, was isolated from cultures of Aspergillus versicolor NRRL 35600. The structure was assigned by 2D NMR data, and confirmed by a biomimetic total synthesis. Versicolamide B is the first member of the paraherquamide-stephacidin family of alkaloids fo...

  11. Effects of Uncaria tomentosa total alkaloid and its components on experimental amnesia in mice: elucidation using the passive avoidance test.

    Science.gov (United States)

    Mohamed, A F; Matsumoto, K; Tabata, K; Takayama, H; Kitajima, M; Watanabe, H

    2000-12-01

    The effects of Uncaria tomentosa total alkaloid and its oxindole alkaloid components, uncarine E, uncarine C, mitraphylline, rhynchophylline and isorhynchophylline, on the impairment of retention performance caused by amnesic drugs were investigated using a step-down-type passive avoidance test in mice. In this test, the retention performance of animals treated with the amnesic and test drugs before training was assessed 24 h after training. Uncaria tomentosa total alkaloid (10-20 mg kg(-1), i.p.) and the alkaloid components (10-40 mg kg(-1), i.p.), as well as the muscarinic receptor agonist oxotremorine (0.01 mg kg(-1), i.p.), significantly attenuated the deficit in retention performance induced by the muscarinic receptor antagonist scopolamine (3 mg kg(-1), i.p.). The effective doses of uncarine C and mitraphylline were larger than those of other alkaloid components. Uncarine E (20 mg kg(-1), i.p.) also blocked the impairment of passive avoidance performance caused by the nicotinic receptor antagonist mecamylamine (15 mg kg(-1), i.p.) and the N-methyl-D-aspartate (NMDA) receptor antagonist (+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP; 7.5 mg kg(-1), i.p.), but it failed to affect the deficit caused by the benzodiazepine receptor agonist diazepam (2 mg kg(-1), i.p.). Rhynchophylline significantly reduced the mecamylamine-induced deficit in passive avoidance behaviour, but it failed to attenuate the effects of CPP and diazepam. These results suggest that Uncaria tomentosa total alkaloids exert a beneficial effect on memory impairment induced by the dysfunction of cholinergic systems in the brain and that the effect of the total alkaloids is partly attributed to the oxindole alkaloids tested. Moreover, these findings raised the possibility that the glutamatergic systems are implicated in the anti-amnesic effect of uncarine E.

  12. Pyridinoacridine alkaloids of marine origin: NMR and MS spectral data, synthesis, biosynthesis and biological activity

    Directory of Open Access Journals (Sweden)

    Louis P. Sandjo

    2015-09-01

    Full Text Available This review focuses on pyridoacridine-related metabolites as one biologically interesting group of alkaloids identified from marine sources. They are produced by marine sponges, ascidians and tunicates, and they are structurally comprised of four to eight fused rings including heterocycles. Acridine, acridone, dihydroacridine, and quinolone cores are features regularly found in these alkaloid skeletons. The lack of hydrogen atoms next to quaternary carbon atoms for two or three rings makes the chemical shift assignment a difficult task. In this regard, one of the aims of this review is the compilation of previously reported, pyridoacridine 13C NMR data. Observations have been made on the delocalization of electrons and the presence of some functional groups that lead to changes in the chemical shift of some carbon resonances. The lack of mass spectra information for these alkaloids due to the compactness of their structures is further discussed. Moreover, the biosynthetic pathways of some of these metabolites have been shown since they could inspire biomimetic synthesis. The synthesis routes used to prepare members of these marine alkaloids (as well as their analogues, which are synthesized for biological purposes are also discussed. Pyridoacridines were found to have a large spectrum of bioactivity and this review highlights and compares the pharmacophores that are responsible for the observed bioactivity.

  13. Lepadiformine: a case study of the value of total synthesis in natural product structure elucidation.

    Science.gov (United States)

    Weinreb, Steven M

    2003-01-01

    Since the emergence of routine X-ray crystallography and high-field FT NMR in the mid-twentieth century, the importance of total synthesis in structure elucidation has become underappreciated by most organic chemists. However, the limitations and fallibility of spectral methodology has recently been highlighted by the mischaracterization of a number of complex natural products, the correct structures of which were all ultimately assigned by total synthesis. This account describes how total synthesis was not only instrumental in disproving the erroneously assigned structure of the marine alkaloid, lepadiformine, but also was also pivotal in establishing the correct structure and absolute configuration.

  14. A General, Concise Strategy that Enables Collective Total Syntheses of over 50 Protoberberine and Five Aporhoeadane Alkaloids within Four to Eight Steps.

    Science.gov (United States)

    Zhou, Shiqiang; Tong, Rongbiao

    2016-05-17

    A concise, catalytic, and general strategy that allowed efficient total syntheses of 22 natural 13-methylprotoberberines within four steps for each molecule is reported. This synthesis represents the most efficient and shortest route to date, featuring three catalytic processes: CuI-catalyzed redox-A(3) reaction, Pd-catalyzed reductive carbocyclization, and PtO2 -catalyzed hydrogenation. Importantly, this new strategy to the tetracyclic framework has also been applied to the collective concise syntheses of >30 natural protoberberines (without 13-methyl group) and five aporhoeadane alkaloids.

  15. Synthesis of (R-Dihydropyridones as Key Intermediates for an Efficient Access to Piperidine Alkaloids

    Directory of Open Access Journals (Sweden)

    Serkos A Haroutounian

    2007-04-01

    Full Text Available The efficient transformation of D-glucal to (2R-hydroxymethyldihydro-pyridinone 5 in seven steps and 35 % overall yield is reported. Dihydropyridone 5 constitutes a versatile chiral building block for the synthesis of various piperidine alkaloids. In this regard, 5 was converted to piperidinol 13 and piperidinone 15, that may be further elaborated for the syntheses of (+-desoxoprosophylline (1 and deoxymannojirimycin (3 or D-mannolactam (4, respectively.

  16. Double reductive cyclization: A facile synthesis of the indoloquinoline alkaloid cryptotackieine

    Digital Repository Service at National Institute of Oceanography (India)

    Parvatkar, P.T.; Parameswaran, P.S.; Tilve, S.G.

    retro- synthetic analysis of 3 indicated that it should be possi- ble to prepare 3 via a one-pot double reduction, isomerization, and double cyclization (Scheme 1). The Keywords: Indoloquinoline alkaloid; Perkin reaction; Cryptotackieine; Neocryptolepine... CH 3 1 The interesting biological activity of 1 has generated overall yield using an intramolecular aza-Wittig reaction 9 as the key step. Wang and co-workers reported the synthesis of 1 in four steps via a biradical pathway 10 with an overall yield...

  17. Synthesis of some /sup 11/C-labelled alkaloids

    Energy Technology Data Exchange (ETDEWEB)

    Laangstroem, B.; Antoni, G.; Halldin, H.; Svaerd, H.; Bergson, G. (Univ. of Uppsala (Sweden) Inst. of Chemistry)

    1982-01-01

    Using (/sup 11/C)-methyl iodide in N-alkylation reactions in dimethylformamide (DMF), the alkaloids N-(/sup 11/C-methyl)-morphine, N-(/sup 11/C-methyl)-codeine, 6-N(methyl)-9, 10-dihydroergotamine, 6-N-(/sup 11/C-methyl)-bromocriptine and N-(/sup 11/C-methyl)-nicotine have been synthesized in radiochemical yields of 50-95%, within 5-10 min of introducing (/sup 11/C)-methyl iodide into the reaction vial. (/sup 11/C)-Methyl iodide was obtained within 4-7 min from (/sup 11/C)-carbon dioxide prepared by the /sup 14/N(p,..cap alpha..)/sup 11/C reaction.

  18. Total Synthesis and the Biological Activities of (±-Norannuradhapurine

    Directory of Open Access Journals (Sweden)

    Surachai Nimgirawath

    2008-12-01

    Full Text Available The structure previously assigned to the phenolic noraporphine alkaloid, (--norannuradhapurine has been confirmed by a total synthesis of the racemic alkaloid in which the key step involved the formation of the C ring by a radical-initiated cyclization. although inactive against Staphylococcus aureus ATCC25932, Escherichia coli ATCC10536 and Candida albicans ATCC90028, (±-norannuradhapurine inhibits the production of NO, PGE2, TNF-a, IL-1b and IL-6 and the expression of iNOS and COX-2 in RAW 264.7 macrophages stimulated with LPS in vitro.

  19. Patterns of indole alkaloids synthesis in response to heat shock, 5-azacytidine and Na-butyrate treatment of cultured catharanthus roseus mesophyll protoplasts

    International Nuclear Information System (INIS)

    Alkaloids of C. roseus are in high demand for therapeutic and other reasons. Cultured Catharanthus cells can produce limited quantities of these alkaloids. The authors have found that cultured mesophyll protoplasts in the presence of 14C-Tryptamine are capable of synthesizing alkaloids. The pattern of alkaloids synthesis changes when protoplasts are subjected to a heat shock at 370C. The heat shocked protoplasts incorporated 33% more 14C-Tryptamine and produced 3 new types of alkaloids. Treatment of protoplasts with 5-azacytidine, a DNA hypomethylating agent and Na-butyrate which induces hyperacetylation of histones produced qualitative and quantitative changes in the alkaloid pattern. Four new alkaloids following the above treatments were detected by TLC and HPLC of the extracts. It is suggested that the alkaloid pattern of the cultured protoplasts can be altered by treatment with compounds known as regulators of gene expression. Work is in progress to isolate and identify these new alkaloids

  20. Patterns of indole alkaloids synthesis in response to heat shock, 5-azacytidine and Na-butyrate treatment of cultured catharanthus roseus mesophyll protoplasts

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, M.; Cutler, A.J.

    1986-04-01

    Alkaloids of C. roseus are in high demand for therapeutic and other reasons. Cultured Catharanthus cells can produce limited quantities of these alkaloids. The authors have found that cultured mesophyll protoplasts in the presence of /sup 14/C-Tryptamine are capable of synthesizing alkaloids. The pattern of alkaloids synthesis changes when protoplasts are subjected to a heat shock at 37/sup 0/C. The heat shocked protoplasts incorporated 33% more /sup 14/C-Tryptamine and produced 3 new types of alkaloids. Treatment of protoplasts with 5-azacytidine, a DNA hypomethylating agent and Na-butyrate which induces hyperacetylation of histones produced qualitative and quantitative changes in the alkaloid pattern. Four new alkaloids following the above treatments were detected by TLC and HPLC of the extracts. It is suggested that the alkaloid pattern of the cultured protoplasts can be altered by treatment with compounds known as regulators of gene expression. Work is in progress to isolate and identify these new alkaloids.

  1. "Scolicidal effect of alcoholic, aqueous and total alkaloids of Peganum Harmala L. (Syrian Rue against hydatid cysts protoscolices "

    Directory of Open Access Journals (Sweden)

    Mahdavi M

    2002-08-01

    Full Text Available Introduction: Alcoholic and aqueous extracts and total alkaloids of the seed of (Syrian rue peganum harmala L. as scolicidal compound against Hydatid cyst protoscolices were assessed in this study. Methods and Materials: This study was carried out both invitro and by inoculating inside the intact cysts in the shaking bath and dry incubator at 37°c. Different concentration of suspensions were tested in different exposure times. Mortality of protoscolices was determined by their loss of mortality, ability to take vital stains and inactivity of flame cells. Results: The results indicated that alcoholic extract had scolicidal effect against protoscolices; total alkaloids had stronger action and rapid effect on protoscolices.

  2. Horizontal acquisition of toxic alkaloid synthesis in a clade of plant associated fungi.

    Science.gov (United States)

    Marcet-Houben, Marina; Gabaldón, Toni

    2016-01-01

    Clavicipitaceae is a fungal group that comprises species that closely interact with plants as pathogens, parasites or symbionts. A key factor in these interactions is the ability of these fungi to synthesize toxic alkaloid compounds that contribute to the protection of the plant host against herbivores. Some of these compounds such as ergot alkaloids are toxic to humans and have caused important epidemics throughout history. The gene clusters encoding the proteins responsible for the synthesis of ergot alkaloids and lolines in Clavicipitaceae have been elucidated. Notably, homologs to these gene clusters can be found in distantly related species such as Aspergillus fumigatus and Penicillium expansum, which diverged from Clavicipitaceae more than 400 million years ago. We here use a phylogenetic approach to analyze the evolution of these gene clusters. We found that the gene clusters conferring the ability to synthesize ergot alkaloids and loline emerged first in Eurotiomycetes and were then likely transferred horizontally to Clavicipitaceae. Horizontal gene transfer is known to play a role in shaping the distribution of secondary metabolism clusters across distantly related fungal species. We propose that HGT events have played an important role in the capability of Clavicipitaceae to produce two key secondary metabolites that have enhanced the ability of these species to protect their plant hosts, therefore favoring their interactions. PMID:26688468

  3. Biodegradable poly(lactic acid) microspheres containing total alkaloids of Caulis sinomenii

    Indian Academy of Sciences (India)

    Wen Zhang; Xiaojie Lin; Xingxiang Zhang

    2011-12-01

    The fabrication of biodegradable poly(lactic acid) (PLA) microspheres containing total alkaloids of Caulis sinomenii was investigated. The formation, diameter, morphology and properties of the microspheres were characterized using Fourier transform infrared spectroscopy (FT–IR), laser particle size analyser and scanning electron microscopy (SEM), etc. In vitro releasing behaviour was also investigated using UV-Vis spectrometer. As a result, the drug-loaded microspheres with a narrower distributive, rounder and smoother surface were prepared. Drug-releasing behaviour from microspheres was affected by the concentration of emulsifier and the stirring rate. The results demonstrated that a medicated system, which can be potentially applied within a drug delivery system, was designed. This system acts in a systematic manner for the treatment of rheumatoid arthritis.

  4. Asymmetric total synthesis of vindoline.

    Science.gov (United States)

    Kato, Daisuke; Sasaki, Yoshikazu; Boger, Dale L

    2010-03-24

    A concise asymmetric total synthesis of (-)-vindoline (1) is detailed based on a tandem intramolecular [4+2]/[3+2] cycloaddition cascade of a 1,3,4-oxadiazole inspired by the natural product structure, in which the tether linking the initiating dienophile and oxadiazole bears a chiral substituent that controls the facial selectivity of the initiating Diels-Alder reaction and sets absolute stereochemistry of the remaining six stereocenters in the cascade cycloadduct. This key reaction introduces three rings and four C-C bonds central to the pentacyclic ring system setting all six stereocenters and introducing essentially all the functionality found in the natural product in a single step. Implementation of the approach also required the development of a unique ring expansion reaction to provide a six-membered ring suitably functionalized for introduction of the Delta (6, 7)-double bond found in the core structure of vindoline and defined our use of a protected hydroxymethyl group as the substituent used to control the stereochemical course of the cycloaddition cascade.

  5. Synthesis of Carbazole Alkaloids by Ring-Closing Metathesis and Ring Rearrangement-Aromatization.

    Science.gov (United States)

    Dhara, Kalyan; Mandal, Tirtha; Das, Joydeb; Dash, Jyotirmayee

    2015-12-21

    Aprocess for the assembly of carbazole alkaloids has been developed on the basis of ring-closing metathesis (RCM) and ringrearrangement-aromatization (RRA) as the key steps. This method is based on allyl Grignard addition to isatin derivatives to provide smooth access to 2,2-diallyl 3-oxindole derivatives through a 1,2-allyl shift. The diallyl derivatives were used as RCM precursors to afford a novel class of spirocyclopentene-3-oxindole derivatives, which underwent a novel RRA reaction to afford carbazole derivatives. The synthetic sequence to carbazoles was shortened by combining the RCM and RRA steps in an orthogonal tandem catalytic process. The utility of this methodology was further demonstrated by the straightforward synthesis of carbazole alkaloids, including amukonal derivative, girinimbilol, heptaphylline, and bis(2-hydroxy-3-methylcarbazole). PMID:26768698

  6. Stereoselective Total Synthesis of (-)-Renieramycin T.

    Science.gov (United States)

    Yokoya, Masashi; Toyoshima, Ryoko; Suzuki, Toshihiro; Le, Vy H; Williams, Robert M; Saito, Naoki

    2016-05-20

    A stereoselective total synthesis of (-)-Renieramycin T (1t) from a key tetrahydroisoquinoline intermediate previously utilized in our formal total synthesis of Ecteinascidin 743 is described. The synthesis features a concise approach for construction of the pentacyclic framework using a Pictet-Spengler cyclization of bromo-substituted carbinolamine 17, which obviates the regioselectivity problem of the Pictet-Spengler cyclization. The results of cytotoxicity studies are also presented. PMID:27019081

  7. Total synthesis of solanoeclepin A

    Science.gov (United States)

    Tanino, Keiji; Takahashi, Motomasa; Tomata, Yoshihide; Tokura, Hiroshi; Uehara, Taketo; Narabu, Takashi; Miyashita, Masaaki

    2011-06-01

    Cyst nematodes are troublesome parasites that live on, and destroy, a range of important host vegetable plants. Damage caused by the potato cyst nematode has now been reported in over 50 countries. One approach to eliminating the problem is to stimulate early hatching of the nematodes, but key hatching stimuli are not naturally available in sufficient quantities to do so. Here, we report the first chemical synthesis of solanoeclepin A, the key hatch-stimulating substance for potato cyst nematode. The crucial steps in our synthesis are an intramolecular cyclization reaction for construction of the highly strained tricyclo[5.2.1.01,6]decane skeleton (DEF ring system) and an intramolecular Diels-Alder reaction of a furan derivative for the synthesis of the ABC carbon framework. The present synthesis has the potential to contribute to addressing one of the critical food issues of the twenty-first century.

  8. New Perspectives in the Chemistry of Marine Pyridoacridine Alkaloids

    OpenAIRE

    Alois Plodek; Franz Bracher

    2016-01-01

    Secondary metabolites from marine organisms are a rich source of novel leads for drug development. Among these natural products, polycyclic aromatic alkaloids of the pyridoacridine type have attracted the highest attention as lead compounds for the development of novel anti-cancer and anti-infective drugs. Numerous sophisticated total syntheses of pyridoacridine alkaloids have been worked out, and many of them have also been extended to the synthesis of libraries of analogues of the alkaloids...

  9. A Convergent Enantioselective Total Synthesis of (-)-Perhydrohistrionicotoxin with an Intramolecular Imino Ene-type Reaction as a Key Step

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Hagberg, Lars

    1998-01-01

    A convergent enantioselective total synthesis of the neurotoxic spirocyclic alkaloid (-)-perhydrohistrionicotoxin (2) is described. A Lewis acid-mediated intramolecular imine ene-type reaction was used for the key spirocyclisation step (14 to 3, with 3 being obtained as a single diastereoisomer)....

  10. Antinociceptive and Anti-Inflammatory Effects of Total Alkaloid Extract from Fumaria capreolata

    Directory of Open Access Journals (Sweden)

    Noureddine Bribi

    2015-01-01

    Full Text Available Fumaria capreolata is used in traditional medicine in North Africa for its gastrointestinal and anti-inflammatory activities. The present study investigates the effects of total alkaloids extracted from the aerial parts of Fumaria capreolata (AFC on LPS-induced production of proinflammatory mediators (IL-6, IL-1β, iNOS, TNF-α, COX-2, and MIP-2 in RAW264.7 cells. AFC significantly reduced the inflammatory response inhibiting the production of nitric oxide (NO and IL-6 in a dose-dependent manner, without affecting the viability of cells, and downregulated mRNA expression of proinflammatory key players: IL-6, IL-1β, iNOS, TNF-α, and COX-2. AFC antinociceptive and anti-inflammatory properties were also evaluated on the acetic acid- and formalin-induced pain models in mice. AFC oral administration significantly inhibited acetic acid-induced writhes and reduced formalin-induced paw licking time. Therefore, AFC may be a potential candidate for the treatment of inflammatory diseases, such as colitis and arthritis.

  11. Study of Total Alkaloids from Rhizoma Coptis Chinensis on Experimental Gastric Ulcers

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective: To study the effects of total alkaloids (TA) extracted from Rhizoma Coptis Chinensis on experimental gastric ulcer models. Methods: Four kinds of experimental ulcer models were established respectively by water-immersion stress, intragastric ethanol, acetic acid erosion, and pylorus ligation. The anti-ulcer effects of TA were evaluated, and compared with that of berberine (Ber) and cimetidine(Cim). Results: TA showed significant inhibitory effects on ulcerative formation induced by water-immersion stress, intragastric ethanol, and pylorus l igation in dose-dependent manner, and showed therapeutic effect on acetic acid erosion-inducing ulcer, in comparison with the control group. The anti-ulcer activity of Ber was less than TA containing equal content of Ber. TA significantly reduced the free acidity, total acidity and total acid output, but didn't affect the gastric juice volume, gastric pepsin activity, adherent mucus quantity of stomach wall and free mucus dissolving in gastric juice. The suppressive activities of TA on gastric acid secretion didn't occur when it was administered into dodecadactylon at a dose of 360 mg/kg wt. Moreover,when compared with Cim, the inhibitory effect of TA on gastric acid secretion isn't proportional to the inhibitory effects on the formation of the 4 kinds of experimental ulcers. Conclusion: TA is a potent candidate in therapeutic drugs for treating gastric ulcer. Its anti-ulcer effective components and mechanism is not only related to Ber and inhibition of gastric acid, but also to other ingredients of TA and mechanism so far unknown.

  12. Asymmetric Total Synthesis of (-)-Cladospolide B

    Institute of Scientific and Technical Information of China (English)

    WANG,Wen-Kuan; ZHANG,Ji-Yong; HE,Jin-Mei; TANG,Shi-Bing; WANG,Xiao-Lei; SHE,Xue-Gong; PAN,Xin-Fu

    2008-01-01

    An enantioselective total synthesis of (-)-cladospolide B was described.The key steps in this synthesis include (a) a Sharpless asymmetric dihydroxylation to elaborate syn diol at C-4 and C-5 positions;(b) a Mitsunobu esterification to reverse the configuration at C-11 from (S) to (R);and (c) a ring-closing metathesis to access the 12-membered macrocyclic ring.

  13. A modified total synthesis of cystothiazole A

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A modified total synthesis of cystothiazole A is described. In this synthetic strategy, a one-step transformation of acylated oxazolidinone to β-ketoester has been successfully applied, thus making the synthetic route more efficient. This method may also be potentially applied in synthesis of other related β-substituted-β-methoxyl acrylates (bb-MOAs).

  14. Total Synthesis of (±)-Celaphanol A

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The first total synthesis of (±)-Celaphanol A was accomplished starting from α-cyclocitral and 3,4-dimethoxy benzyl chloride via a six-step process, in which the intramolecular cyclization of ketone 4 with BF3@Et2O afforded an all-cis isomer intermediate for synthesis of aromatic tricyclic diterpenes.

  15. Total Synthesis of (±)-Hibiscone C

    OpenAIRE

    Ungureanu, Sinziana; Meadows, Maggie; Smith, Joel; Duff, David B.; Burgess, James M.; Goess, Brian C.

    2011-01-01

    A total synthesis of (±)- hibiscone C, one member of the furanosteroid family of natural products that also includes viridin and wortmannin, is reported. Two new pathways for formation of the key diacyl furan subunit are described.

  16. The First Total Synthesis of Isoliquiritin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A first total synthesis of isoliquiritin was accomplished starting from p-hydroxy- benzaldehyde and 2,4-dihydroxyacetylphenone. The key step is condensation reaction. In synthetic process need not protect the hydroxy group of reacting substance.

  17. A divergent approach to the synthesis of the yohimbinoid alkaloids venenatine and alstovenine

    Science.gov (United States)

    Lebold, Terry P.; Wood, Jessica L.; Deitch, Josh; Lodewyk, Michael W.; Tantillo, Dean J.; Sarpong, Richmond

    2013-02-01

    The yohimbinoid alkaloids continue to receive considerable attention from the synthetic community because of their interesting chemical structures and varied biological activity. Although there are several elegant syntheses of certain members of this group of alkaloids, a truly unified approach has yet to be developed. In short, general approaches to this compound class are hampered by a lack of complete control in setting the C(3) stereocentre at a late stage. Herein, we report that a functionalized hydrindanone enables a divergent strategy that builds on existing precedent to address this long-standing challenge. Utilizing an aminonitrile intermediate, the stereochemistry at C(3) of the yohimbinoid skeleton can be controlled effectively in a Pictet-Spengler reaction. We applied this approach to the first total syntheses of the C(3) epimeric natural products venenatine and alstovenine.

  18. Quantitative analysis of total retronecine esters-type pyrrolizidine alkaloids in plant by high performance liquid chromatography

    International Nuclear Information System (INIS)

    Pyrrolizidine alkaloids (PAs) are alkaloids which typically contain a necine (7-hydroxy-1-hydroxymethyl-6,7-dihydro-5H-pyrrolizidine) base unit, and they can be found in one third of the higher plants around the world. They are hepatotoxic, mutagenic and carcinogenic and pose a threat to human health and safety. A specific, quick and sensitive method is therefore needed to detect and quantify the PAs sometimes in trace amount in herbs, tea or food products. Based on high performance liquid chromatography with prior derivatization of the alkaloids using o-chloranil and Ehrlich's reagent, we report an improved method for quantitative analysis of the total amount of retronecine esters-type pyrrolizidine alkaloids (RET-PAs) in a plant extract. The total quantitation of RET-PAs is achieved because of a common colored retronecine marker, a 7-ethoxy-1-ethoxylmethyl retronecine derivative, is produced with all the different RET-PAs during the derivatization reaction. The chemical identity of the common retronecine marker was characterized on-line by positive mode electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopy. The limit of detection using the improved method is 0.26 nmol mL-1 and the limit of quantitation is 0.79 nmol mL-1. The advantages of this method are much enhanced sensitivity in detection and quantitation, and, no restriction on the choice of RET-PA as a calibration standard. Application of the developed method to the quantitation of total RET esters-type PAs in Senecio scandens from different regions of China is also reported

  19. Antibacterial, antioxidant and cytotoxic studies of total saponin, alkaloid and sterols contents of decoction of Joshanda: identification of components through thin layer chromatography.

    Science.gov (United States)

    Khan, Haroon; Khan, Murad Ali; Abdullah

    2015-03-01

    The current study was aimed to assess antibacterial, antioxidant and cytotoxic activity of total saponin, alkaloid and sterol contents of Joshanda decoction followed by its constituent's analysis via thin layer chromatography (TLC). Saponins and alkaloids showed prominent antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Bacillus cereus and Klebsiella pneumoniae whereas sterols only against S. aureus. Saponin and alkaloid contents of 97 and 108 µg/ml, respectively, showed prominent free radical scavenging activity against 1,1-diphenyl-2-picrylhidrazyl, with mild cytotoxicity in brine shrimp cytotoxic test. Under ultraviolet light at 254 nm, TLC of total saponins showed eight different compounds, total sterols comprising three while total alkaloids two compounds of various polarities. It is concluded that the various contents of Joshanda decoction possess outstanding susceptibility against bacteria implicating primarily upper respiratory tract infections augmented by strong antioxidant activity. PMID:23235996

  20. New Perspectives in the Chemistry of Marine Pyridoacridine Alkaloids

    Science.gov (United States)

    Plodek, Alois; Bracher, Franz

    2016-01-01

    Secondary metabolites from marine organisms are a rich source of novel leads for drug development. Among these natural products, polycyclic aromatic alkaloids of the pyridoacridine type have attracted the highest attention as lead compounds for the development of novel anti-cancer and anti-infective drugs. Numerous sophisticated total syntheses of pyridoacridine alkaloids have been worked out, and many of them have also been extended to the synthesis of libraries of analogues of the alkaloids. This review summarizes the progress in the chemistry of pyridoacridine alkaloids that was made in the last one-and-a-half decades. PMID:26821033

  1. Total Synthesis of balanol, Part 2

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Kelly, Nicholas; Tedenborg, Lars;

    1997-01-01

    A convergent enantioselective total synthesis of the natural product (-)-balanol (1) is described. In addition to benzophenone fragment 8, key intermediates are chiral bicyclic aziridine 3 and the corresponding epoxide 4, both of which undergo highly regio- and stereoselective nucleophilic ring-o...

  2. Enantioselective Total Synthesis of Plectosphaeroic Acid B

    OpenAIRE

    Jabri, Salman Y.; Overman, Larry E.

    2013-01-01

    The first total synthesis of a member of the plectosphaeroic acid family of fungal natural products is reported. Key steps include the late-stage formation of the hindered N6–C9″ bond and stereoselective introduction of the two methylthio substituents.

  3. The total synthesis of (-)-cryptocaryol A.

    Science.gov (United States)

    Dias, L C; Kuroishi, P K; de Lucca, E C

    2015-03-28

    A stereoselective total synthesis of (-)-cryptocaryol A (1) is described. Key features of the 17-step route include the use of three boron-mediated aldol reaction-reduction sequences to control all stereocenters and an Ando modification of the Horner-Wadsworth-Emmons olefination that permitted the installation of the Z double bond of the α-pyrone ring. PMID:25695350

  4. The total synthesis of pantocin B.

    Science.gov (United States)

    Sutton, A E; Clardy, J

    2000-02-10

    [reaction: see text] Pantocin B, an unusual antibiotic produced by Erwinia herbicola, effectively controls E. amylovora, the pathogen causing the plant disease fire blight. A total synthesis of pantocin B from L-alanine, glycine, and L-malic acid is reported. PMID:10814312

  5. Total synthesis of insect antifeedant drimane sesquiterpenes.

    NARCIS (Netherlands)

    Jansen, B.J.M.

    1993-01-01

    The investigations described in this thesis deal with the total synthesis of sesquiterpenes of the drimane family, named for their widespread occurrence in the stem bark of South American Drimys species. These compounds contain the bicyclofarnesol nucleus 1 , which is invariably oxi

  6. Stereocontrolled total synthesis of hedyotol A.

    Science.gov (United States)

    Kawabe, Yusuke; Ishikawa, Ryo; Akao, Yusuke; Yoshida, Atsushi; Inai, Makoto; Asakawa, Tomohiro; Hamashima, Yoshitaka; Kan, Toshiyuki

    2014-04-01

    The total synthesis of hedyotol A (1), a natural product isolated from Hedyotis lawsoniae (DC.) Wight et Arn. (Rubiaceae), was accomplished in a highly stereocontrolled manner. Key steps include an L-proline-catalyzed cross-aldol reaction and the biomimetic construction of a furofuran lignan skeleton through a quinomethide intermediate. PMID:24660822

  7. Total synthesis of aeruginosin 98B.

    Science.gov (United States)

    Trost, Barry M; Kaneko, Toshiyuki; Andersen, Neil G; Tappertzhofen, Christoph; Fahr, Bruce

    2012-11-21

    The first total synthesis of aeruginosin 98B was accomplished. The key step is a highly diastereoselective Pd-catalyzed intramolecular asymmetric allylic alkylation reaction of a diastereomeric mixture of allylic carbonates that is enabled by the use of racemic phosphine ligand L1.

  8. Preparation and In vitro Evaluation of Ethosomal Total Alkaloids of Sophora alopecuroides Loaded by a Transmembrane pH-Gradient Method

    OpenAIRE

    Zhou, Yan; Wei, Yuhui; Liu, Huanxiang; Zhang, Guoqiang; Wu, Xin’an

    2010-01-01

    A novel transmembrane pH gradient active loading method to prepare alkaloids binary ethosomes was developed in this work. Using this novel method, binary ethosomes containing total alkaloids extracted from Sophora alopecuroides (TASA) were prepared successfully at the temperature below the phase transition temperature (Tc) of the phosphatidyl choline (PC). Several factors affecting this method were investigated. The qualities of the TASA binary ethosomes were characterized by the shape, parti...

  9. Content determination exploration of uncaria total alkaloid%钩藤总生物碱的含量测定研究

    Institute of Scientific and Technical Information of China (English)

    许家洁; 于江波; 徐军; 仲崇琳; 杨美林

    2015-01-01

    Objective:To establish the method for content determination of uncaria total alkaloid.Methods:The contents of uncaria total alkaloid from uncaria total alkaloid extractive were determined by ultraviolet spectrophotometry.The contents of uncaria total alkaloid from uncaria total alkaloid extractive were determined by HPLC.Results:The incoming sample amount of uncaria total alkaloid was 0.168~0.840 μg,the peak area and incoming sample amount had good linear relationship(r=0.9995),the average recovery was 98.98%,RSD=1.31(n=5).Conclusion:This method was sensitive and accurate,which could be used for the content determination of uncaria total alkaloid.%目的:建立测定钩藤总生物碱含量的方法。方法:用紫外分光光度法测定钩藤总生物碱提取物中的钩藤总生物碱含量。采用高效色谱法测定钩藤总生物碱提取物中的钩藤碱含量。结果:钩藤碱的进样量0.168~0.840μg,其峰面积与进样量具有良好的线性关系(r=0.9995),平均回收率98.98%,RSD=1.31(n=5)。结论:该方法灵敏、准确,可用于钩藤总生物碱的含量测定。

  10. First Total Synthesis of Gliomasolide C and Formal Total Synthesis of Sch-725674.

    Science.gov (United States)

    Seetharamsingh, B; Khairnar, Pankaj V; Reddy, D Srinivasa

    2016-01-01

    Syntheses of two 14-membered macrolides Sch-725674 and Gliomasolide C are described here. The first total synthesis of Gliomasolide C, the short synthesis of Sch-725674, and regioselective Wacker oxidation of internal olefin are the highlights of this disclosure. In addition, a key macrocycle with orthogonal functionalities was designed and synthesized on a gram scale for the generation of analogues. PMID:26633579

  11. Total Alkaloids of Sophora alopecuroides Inhibit Growth and Induce Apoptosis in Human Cervical Tumor HeLa Cells In vitro

    Science.gov (United States)

    Li, Jian-Guang; Yang, Xiao-Yi; Huang, Wei

    2016-01-01

    Background: Uygur females of Xinjiang have the higher incidence of cervical tumor in the country. Alkaloids are the major active ingredients in Sophora alopecuroides, and its antitumor effect was recognized by the medical profession. Xinjiang is the main site of S. alopecuroides production in China so these plants are abundant in the region. Studies on the antitumor properties of total alkaloids of S. alopecuroides (TASA) can take full use of the traditional folk medicine in antitumor unique utility. Objectives: To explore the effects of TASA on proliferation and apoptosis of human cervical tumor HeLa cells in vitro. Materials and Methods: TASA was extracted, purified, and each monomer component was analyzed by high-performance liquid chromatography. The effect of TASA at different concentrations on the survival of HeLa cells was determined after 24 h using the Cell Counting Kit-8. In addition, cells were photographed using an inverted microscope to document morphological changes. The effect of TASA on apoptotic rate of HeLa cells was assessed by flow cytometry. Results: Monomers of TASA were found to be sophoridine, matrine, and sophocarpine. On treatment with 8.75 mg/ml of TASA, more than 50% of HeLa cells died, and cell death rate increased further with longer incubation. The apoptotic rates of HeLa cells in the experimental groups were 16.0% and 33.3% at concentrations of 6.25 mg/ml and 12.50 mg/ml, respectively. Conclusion: TASA can induce apoptosis in cervical tumor HeLa cells, and it has obvious inhibitory effects on cell growth. SUMMARY Total alkaloids of Sophora alopecuroides (TASA) exhibits anti-human cervical tumor propertiesMonomer component of TASA was analyzed by high-performance liquid chromatography, and its main effect component are sophoridine, matrine, and sophocarpineTASA inhibits growth and induces apoptosis in HeLa cells. Abbreviations used: TASA: Total alkaloids of S. alopecuroides, CCK-8: Cell Counting Kit-8, FBS: Fetal bovine serum, PBS

  12. Nineteen-step total synthesis of (+)-phorbol.

    Science.gov (United States)

    Kawamura, Shuhei; Chu, Hang; Felding, Jakob; Baran, Phil S

    2016-04-01

    Phorbol, the flagship member of the tigliane diterpene family, has been known for over 80 years and has attracted attention from many chemists and biologists owing to its intriguing chemical structure and the medicinal potential of phorbol esters. Access to useful quantities of phorbol and related analogues has relied on isolation from natural sources and semisynthesis. Despite efforts spanning 40 years, chemical synthesis has been unable to compete with these strategies, owing to its complexity and unusual placement of oxygen atoms. Purely synthetic enantiopure phorbol has remained elusive, and biological synthesis has not led to even the simplest members of this terpene family. Recently, the chemical syntheses of eudesmanes, germacrenes, taxanes and ingenanes have all benefited from a strategy inspired by the logic of two-phase terpene biosynthesis in which powerful C-C bond constructions and C-H bond oxidations go hand in hand. Here we implement a two-phase terpene synthesis strategy to achieve enantiospecific total synthesis of (+)-phorbol in only 19 steps from the abundant monoterpene (+)-3-carene. The purpose of this synthesis route is not to displace isolation or semisynthesis as a means of generating the natural product per se, but rather to enable access to analogues containing unique placements of oxygen atoms that are otherwise inaccessible. PMID:27007853

  13. Total Synthesis of Natural Products Using Hypervalent Iodine Reagents

    Science.gov (United States)

    Maertens, Gaetan; L'homme, Chloe; Canesi, Sylvain

    2014-12-01

    We present a review of natural product syntheses accomplished in our laboratory during the last five years. Each synthetic route features a phenol dearomatization promoted by an environmentally benign hypervalent iodine reagent. The dearomatizations demonstrate the “aromatic ring umpolung” concept, and involve stereoselective remodeling of the inert unsaturations of a phenol into a highly functionalized key intermediate that may contain a quaternary carbon center and a prochiral dienone system. Several new oxidative strategies were employed, including transpositions (1,3-alkyl shift and Prins-pinacol), a polycyclization, an ipso rearrangement, and direct nucleophilic additions at the phenol para position. Several alkaloids, heterocyclic compounds, and a polycyclic core have been achieved, including sceletenone (a serotonin reuptake inhibitor), acetylaspidoalbidine (an antitumor agent), fortucine (antiviral and antitumor), erysotramidine (curare-like effect), platensimycin (an antibiotic), and the main core of a kaurane diterpene (immunosuppressive agent and stimulator of apoptosis). These concise and in some cases enantioselective syntheses effectively demonstrate the importance of hypervalent iodine reagents in the total synthesis of bioactive natural products.

  14. Total Synthesis of Natural Products Using Hypervalent Iodine Reagents

    Directory of Open Access Journals (Sweden)

    Gaetan eMaertens

    2015-01-01

    Full Text Available We present a review of natural product syntheses accomplished in our laboratory during the last five years. Each synthetic route features a phenol dearomatization promoted by an environmentally benign hypervalent iodine reagent. The dearomatizations demonstrate the aromatic ring umpolung concept, and involve stereoselective remodeling of the inert unsaturations of a phenol into a highly functionalized key intermediate that may contain a quaternary carbon center and a prochiral dienone system. Several new oxidative strategies were employed, including transpositions (1,3-alkyl shift and Prins-pinacol, a polycyclization, an ipso rearrangement, and direct nucleophilic additions at the phenol para position. Several alkaloids, heterocyclic compounds, and a polycyclic core have been achieved, including sceletenone (a serotonin reuptake inhibitor, acetylaspidoalbidine (an antitumor agent, fortucine (antiviral and antitumor, erysotramidine (curare-like effect, platensimycin (an antibiotic, and the main core of a kaurane diterpene (immunosuppressive agent and stimulator of apoptosis. These concise and in some cases enantioselective syntheses effectively demonstrate the importance of hypervalent iodine reagents in the total synthesis of bioactive natural products.

  15. Synthesis and Biological Evaluation of Novel 3-Alkylpyridine Marine Alkaloid Analogs with Promising Anticancer Activity

    Directory of Open Access Journals (Sweden)

    Alessandra Mirtes Marques Neves Gonçalves

    2014-07-01

    Full Text Available Cancer continues to be one of the most important health problems worldwide, and the identification of novel drugs and treatments to address this disease is urgent. During recent years, marine organisms have proven to be a promising source of new compounds with action against tumoral cell lines. Here, we describe the synthesis and anticancer activity of eight new 3-alkylpyridine alkaloid (3-APA analogs in four steps and with good yields. The key step for the synthesis of these compounds is a Williamson etherification under phase-transfer conditions. We investigated the influence of the length of the alkyl chain attached to position 3 of the pyridine ring on the cytotoxicity of these compounds. Biological assays demonstrated that compounds with an alkyl chain of ten carbon atoms (4c and 5c were the most active against two tumoral cell lines: RKO-AS-45-1 and HeLa. Micronucleus and TUNEL assays showed that both compounds are mutagenic and induce apoptosis. In addition, Compound 5c altered the cellular actin cytoskeleton in RKO-AS-45-1 cells. The results suggest that Compounds 4c and 5c may be novel prototype anticancer agents.

  16. Total Synthesis of (±)-Integrifolin.

    Science.gov (United States)

    Shimomaki, Katsuya; Kusama, Hiroyuki; Iwasawa, Nobuharu

    2016-07-11

    The total synthesis of (±)-integrifolin has been achieved for the first time through the stereoselective preparation of the bicyclo[5.3.0]decane skeleton based on the tungsten-catalyzed cyclization of acyclic trienynes under photoirradiation conditions. Further key transformations of the cyclized product are the Tamao oxidation through cyclic silyl ether, the introduction of two oxygen functionalities by the oxidation of the diene and the construction of three exo-methylene moieties. PMID:27147582

  17. Bacterial Alkaloids Prevent Amoebal Predation.

    Science.gov (United States)

    Klapper, Martin; Götze, Sebastian; Barnett, Robert; Willing, Karsten; Stallforth, Pierre

    2016-07-25

    Bacterial defense mechanisms have evolved to protect bacteria against predation by nematodes, predatory bacteria, or amoebae. We identified novel bacterial alkaloids (pyreudiones A-D) that protect the producer, Pseudomonas fluorescens HKI0770, against amoebal predation. Isolation, structure elucidation, total synthesis, and a proposed biosynthetic pathway for these structures are presented. The generation of P. fluorescens gene-deletion mutants unable to produce pyreudiones rendered the bacterium edible to a variety of soil-dwelling amoebae. PMID:27294402

  18. Total synthesis of (+)-gelsemine via an organocatalytic Diels-Alder approach.

    Science.gov (United States)

    Chen, Xiaoming; Duan, Shengguo; Tao, Cheng; Zhai, Hongbin; Qiu, Fayang G

    2015-01-01

    The structurally complex alkaloid gelsemine was previously thought to have no significant biological activities, but a recent study has shown that it has potent and specific antinociception in chronic pain. While this molecule has attracted significant interests from the synthetic community, an efficient synthetic strategy is still the goal of many synthetic chemists. Here we report the asymmetric total synthesis of (+)-gelsemine, including a highly diastereoselective and enantioselective organocatalytic Diels-Alder reaction, an efficient intramolecular trans-annular aldol condensation furnishing the prolidine ring and establishing the configuration of the C20 quaternary carbon stereochemical centre. The entire gelsemine skeleton was constructed through a late-stage intramolecular SN2 substitution. The enantiomeric excess of this total synthesis is over 99%, and the overall yield is around 5%. PMID:25995149

  19. Total synthesis and biological investigation of (-)-promysalin.

    Science.gov (United States)

    Steele, Andrew D; Knouse, Kyle W; Keohane, Colleen E; Wuest, William M

    2015-06-17

    Compounds that specifically target pathogenic bacteria are greatly needed, and identifying the method by which they act would provide new avenues of treatment. Herein we report the concise, high-yielding total synthesis (eight steps, 35% yield) of promysalin, a natural product that displays antivirulence phenotypes against pathogenic bacteria. Guided by bioinformatics, four diastereomers were synthesized, and the relative and absolute stereochemistries were confirmed by spectral and biological analysis. Finally, we show for the first time that promysalin displays two antivirulence phenotypes: the dispersion of mature biofilms and the inhibition of pyoverdine production, hinting at a unique pathogenic-specific mechanism of action.

  20. Total synthesis of insect antifeedant drimane sesquiterpenes.

    OpenAIRE

    Jansen, B.J.M.

    1993-01-01

    The investigations described in this thesis deal with the total synthesis of sesquiterpenes of the drimane family, named for their widespread occurrence in the stem bark of South American Drimys species. These compounds contain the bicyclofarnesol nucleus 1 , which is invariably oxidized at C-11 and/or C-12 and often at other sites as well (see figure 8.1).A few rearranged drimanes, e.g., (+)-colorata-4(13),8-dienolide 6 , and (-)-muzigadial 7 , are also isolated from natural products. The re...

  1. Studies on the Synthesis of Morphinan Alkaloid: Preparation of the Key Allylic Silyl Ether Precursor

    Institute of Scientific and Technical Information of China (English)

    Zhen Lei SONG; Yong Qiang TU; Shuan Hu GAO; Yi Jun JIANG; Shu Yu ZHANG

    2005-01-01

    A convergent strategy to the key allylic silyl ether precursor 4 in our synthetic efforts toward morphinan alkaloid is presented. The vital step is the selective 1,2-addition of the organocerium agent of 6 to ketene 5.

  2. Total synthesis of diterpenoid steenkrotin A.

    Science.gov (United States)

    Pan, Saiyong; Xuan, Jun; Gao, Beiling; Zhu, An; Ding, Hanfeng

    2015-06-01

    A concise and diastereoselective total synthesis of the diterpenoid (±)-steenkrotin A is described for the first time. The strategy mainly features three key ring formations: 1) a rhodium-catalyzed O-H bond insertion followed by an intramolecular carbonyl-ene reaction to build up the tetrahydrofuran subunit; 2) sequential SmI2 -mediated Ueno-Stork and ketyl-olefin cyclizations to construct the [5,7] spirobicyclic skeleton; and 3) an intramolecular aldol condensation/vinylogous retro-aldol/aldol sequence to form the final six-membered ring with inversion of the relative configuration at the C7 position. PMID:25891977

  3. The Total Synthesis of Inostamycin A.

    Science.gov (United States)

    Yu, Guangri; Jung, Byunghyuck; Lee, Hee-Seung; Kang, Sung Ho

    2016-02-12

    The first total synthesis of inostamycin A is described. With efficient and stereoselective synthetic routes to aldehyde 3 and ketone 4 developed through asymmetric aldol reactions, addition reactions and reduction, and with chiral building blocks, the two large fragments were coupled with remarkable anti stereoselectivity and efficiency by aldol condensation. The coupling reaction provided the complete carbon skeleton with all the requisite functional groups and stereogenic centers for inostamycin A. The two quaternary carbons at C20 and C16 of ketone 4 were elaborated in a highly stereocontrolled manner by addition reactions of the transmetallated 5 to ethyl ketone 6 and the transmetallated 7 to methyl ketone 8, respectively, in which the use of LaCl3 for transmetallation was critical for high coupling efficiency. PMID:26800259

  4. Design and synthesis of de novo cytotoxic alkaloids by mimicking the bioactive conformation of paclitaxel

    OpenAIRE

    Sun, Liang; Veith, Jean M.; Pera, Paula; Bernacki, Ralph J.; Ojima, Iwao

    2010-01-01

    Novel paclitaxel-mimicking alkaloids were designed and synthesized based on a bioactive conformation of paclitaxel, i.e., REDOR-Taxol. The alkaloid 2 bearing a 5-7-6 tricyclic scaffold mimics REDOR-Taxol best among the compounds designed and was found to be the most potent compound against several drug-sensitive and drug-resistant human cancer cell lines. MD simulation study on the paclitaxel mimics 1 and 2 as well as REDOR-Taxol bound to the 1JFF tubulin structure was quite informative to ev...

  5. Total Synthesis of a Diacetonide Derivative of Thuggacin A.

    Science.gov (United States)

    Yadav, Jhillu S; Dutta, Palash

    2016-03-01

    A highly stereoselective total synthesis of the diacetonide derivative of the antibiotic thuggacin A has been described. The synthesis features the stereoselective Stille cross-coupling reaction to set up the whole carbon framework, aldol condensation to construct the highly substituted conjugated diene, non-Evans syn aldol, CBS reduction, Hantzsch's thiazole synthesis, Horner-Wadsworth-Emmons reaction, and Shiina's macrolactonization. PMID:26856208

  6. Total Synthesis of the Cyanolide A Aglycon

    OpenAIRE

    Gesinski, Michael R.; Rychnovsky, Scott D.

    2011-01-01

    The synthesis of the potent molluscicide, cyanolide A, has been achieved in 10 steps without the use of protecting groups. The synthesis features a key Sakurai macrocyclization/dimerization reaction that simultaneously forms both tetrahydropyran rings and the macrocycle of the natural product.

  7. The total synthesis of cannabisin G

    Directory of Open Access Journals (Sweden)

    YAMU XIA

    2010-12-01

    Full Text Available A convenient method for the synthesis of lignanamide cannabisin G, starting from vanillin, was developed. The convergent synthesis was based on the Stobbe reaction as C–C bond-forming steps to give the skeleton of lignan, which was condensed with a derivative of tyramine to obtain synthetic cannabisin G for the first time.

  8. Efficient synthesis of the C/D rings of atisine-type C20-diterpenoid alkaloids

    Institute of Scientific and Technical Information of China (English)

    De Lin Chen; Feng Peng Wang

    2012-01-01

    A bicyclo[2.2.2]octane C/D ring system,with a lactonic ring at C-8 and C-9,of the atisine-type C20-diterpenoid alkaloids,was successfully synthesized,using an oxidative dearomatization/intramolecular Diels-Alder reaction.

  9. Synthesis of marine-derived 3-alkylpyridinium alkaloids with potent antiprotozoal activity

    NARCIS (Netherlands)

    B. Rodenko; M.I. Al-Salabi; I.A. Teka; W. Ho; N. El-Sabbagh; J.A.M. Ali; H.M.S. Ibrahim; M.J. Wanner; G.J. Koomen; H.P. de Koning

    2011-01-01

    Given the pressing need for new antiprotozoal drugs without cross-resistance with current (failing) chemotherapy, we have explored 3-tridecylpyridinium alkaloids (3TPAs), derivatives of viscosamine, as antiparasitic agents. We have developed a simple synthetic route toward viscosamine and related cy

  10. Total synthesis of (±)-divanillyltetrahydrofuran ferulate

    Indian Academy of Sciences (India)

    Ya-Mu Xia; Jia You; Qi Wang

    2010-05-01

    A convenient method for the synthesis of sesquilignan threo- and erythro-(±)-divanillyltetrahydrofuran ferulate is described. The synthesis was based on a unified synthetic strategy involving two Stobbe condensations to give the skeleton of lignan, and then reduction reaction to form meso- and threo-(±)-secoisolanciresinol. meso- and threo-(±)-secoisolanciresinol were separated by flash column chromatography, followed by intramolecular reaction with TsCl to afford the key intermediate meso- or threo-(±)-shonanin, then condensation with ferulaic acid to obtain sesquilignan threo- or its analogue erythro-(±)-divanillyltetrahydrofuran ferulate.

  11. Design, Synthesis and Evaluation of New Marine Alkaloid-Derived Pentacyclic Structures with Anti-Tumoral Potency

    Directory of Open Access Journals (Sweden)

    Sebastien Boucle

    2015-01-01

    Full Text Available This work describes the synthesis and biological evaluation of a new heterocyclic hybrid derived from the ellipticine and the marine alkaloid makaluvamine A. Pyridoquinoxalinedione 12 was obtained in seven steps with 6.5% overall yield. 12 and its intermediates 1–11 were evaluated for their in vitro cytotoxic activity against different cancer cell lines and tested for their inhibitory activity against the human DNA topoisomerase II. The analysis by electrophoresis shows that the pentacycle 12 inhibits the topoisomerase II like doxorubicine at 100 µM. Compound 9 was found to have an interesting profile, having a cytotoxicity of 15, 15, 15 and 10 μM against Caco-2, HCT-116, Pc-3 and NCI cell lines respectively, without any noticeable toxicity against human fibroblast.

  12. Ultrasound Bath-assisted Enzymatic Hydrolysis Procedures as Extraction Technology of the Total Alkaloid from Portulaca%超声辅助酶解法提取马齿苋总生物碱

    Institute of Scientific and Technical Information of China (English)

    谢彦

    2011-01-01

    利用超声波辅助纤维素酶解法对马齿苋中的总生物碱进行了提取,并用溴甲酚绿比色法与正交试验结合的方法确定了最佳提取条件.%Total alkaloid was extracted from portulaca by ultrasound bath-assisted enzymatic hydrol- ysis procedures, through bromine cresol green colorimetric determinating alkaloid content. Combined with the orthogonal experiment research, best condition of total portulaca alkaloid by ultrasound bath-as- sisted enzymatic hydrolysis procedures is determined.

  13. Total Synthesis of the Antitumor Antibiotic Basidalin.

    Science.gov (United States)

    Acosta, Jaime A M; Muddala, Ramesh; Barbosa, Luiz C A; Boukouvalas, John

    2016-08-01

    The first synthesis of the tetronamide antibiotic basidalin was accomplished in five steps and 39% overall yield from readily available 4-bromo-2-triisopropylsilyloxyfuran and 2-formyl-1,3-dithiane. Highlights include: (i) regio- and stereocontrolled assemblage of a pivotal (Z)-γ-ylidene-β-bromobutenolide intermediate by stereodirected vinylogous aldol condensation (SVAC), (ii) installation of the amino group via aza-Michael addition/elimination, and crucially (iii) facile access to basidalin by late-stage dithiane removal. PMID:27347696

  14. The Total Synthesis of 14-Deoxycrassin and Pseudoplexaurol: A Convergent Synthesis of Cyclization Precursor

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The synthesis of epoxy aldehyde 4, a cyclization precursor for the total synthesis of 14-deoxycrassin and pseudoplexaurol, starting from geraniol in a convergent and stereoselective manner, is described.

  15. Total Synthesis of Mycalolides A and B through Olefin Metathesis.

    Science.gov (United States)

    Kita, Masaki; Oka, Hirotaka; Usui, Akihiro; Ishitsuka, Tomoya; Mogi, Yuzo; Watanabe, Hidekazu; Tsunoda, Masaki; Kigoshi, Hideo

    2015-11-16

    An asymmetric total synthesis of the trisoxazole marine macrolides mycalolides A and B is described. This synthesis involves the convergent assembly of highly functionalized C1-C19 trisoxazole and C20-C35 side-chain segments through the use of olefin metathesis and esterification as well as Julia-Kocienski olefination and enamide formation as key steps. PMID:26450520

  16. First total synthesis of (+/-)-3-hydroxy-11-norcytisine

    DEFF Research Database (Denmark)

    Yohannes, Daniel; Hansen, Camilla Petrycer; Akireddy, Srinivasa Rao;

    2008-01-01

    The first total synthesis of the natural product 3-hydroxy-11-norcytisine ( 1), structurally related to cytisine ( 2), a benchmark ligand at neuronal nicotinic acetylcholine receptors (NNRs), has been achieved. The synthesis permits the unambiguous confirmation of the structure originally proposed...

  17. Total Synthesis of Mycalolides A and B through Olefin Metathesis.

    Science.gov (United States)

    Kita, Masaki; Oka, Hirotaka; Usui, Akihiro; Ishitsuka, Tomoya; Mogi, Yuzo; Watanabe, Hidekazu; Tsunoda, Masaki; Kigoshi, Hideo

    2015-11-16

    An asymmetric total synthesis of the trisoxazole marine macrolides mycalolides A and B is described. This synthesis involves the convergent assembly of highly functionalized C1-C19 trisoxazole and C20-C35 side-chain segments through the use of olefin metathesis and esterification as well as Julia-Kocienski olefination and enamide formation as key steps.

  18. Total synthesis of the potent microtubule-stabilizing agent (+)-discodermolide.

    Science.gov (United States)

    Harried, Scott S; Lee, Christopher P; Yang, Ge; Lee, Tony I H; Myles, David C

    2003-08-22

    The total synthesis of the potent microtubule-stabilizing, antimitotic agent (+)-discodermolide is described. The convergent synthetic strategy takes advantage of the diastereoselective alkylation of a ketone enolate to establish the key C15-C16 bond. The synthesis is amenable to preparation of gram-scale quantities of (+)-discodermolide and analogues.

  19. 小花棘豆总生物碱抑菌作用的研究%Study on Bacteriostasis Efficiency of Total Alkaloids in Oxytropis glabra DC

    Institute of Scientific and Technical Information of China (English)

    王帅; 李怀志; 马明; 张玲; 马春晖

    2012-01-01

    [目的]研究小花棘豆总生物碱的抑菌作用.[方法]通过体外抑菌试验研究小花棘豆总生物碱的抑菌活性、最小抑菌浓度(MIC)、最小杀菌浓度(MBC)和影响小花棘豆总生物碱抑菌效果的因素.[结果]小花棘豆总生物碱对金黄色葡萄球菌、乳房链球菌、化脓链球菌和枯草芽孢杆菌有抑菌作用;其对乳房链球菌和化脓链球菌的MIC为6.3 mg/mL,对金黄色葡萄球菌的MIC为1.6 mg/mL,对枯草芽孢杆菌的MIC为0.8 mg/mL.生物碱在不同pH值下的抑菌活性发生变化;高温使其抑菌活性消失;紫外照射对其稳定性没有影响.[结论]小花棘豆总生物碱对部分革兰氏阳性菌有较好的抑菌作用.%[ Objective ] The purpose of this project aim to study the antimicrobial activities of total alkaloids for Oxytropis glabra DC. [Method] Through bacteriostasis experiments in vitro, antimicrobial activities of total alkaloids for Oxytropis glabra DC on bacteriostasis efficiency, minimal inhibitory concentration, minimal bactericidal concentration, and environmental effect were studied . [Result]The result showed that alkaloid of Oxytropis glabra DC had fairly bacteriostasis for Staphylococcus aureus, Streptococcus uberis, Streptococcus pyogene, Bacillus subtilis; the MIC for Streptococcus uberis and Streptococcus pyogene was 6. 3 mg/Ml, the MIC for Staphylococcus aureus was 1. 6 mg/Ml, the MIC for Bacillus subtilis was 0. 8 mg/ Ml. The diversity of bacteriostasis efficiency of alkaloid happened in different power of hydrogen; the bacteriostasis material has bad heat stability; ultraviolet ray treatment does not affect its stability. [Conclusion] Total alkaloids of Oxytropis glabra DC had obvious bacteriostasis effect for Gram - positive bacteria.

  20. SP825树脂分离纯化益母草总黄酮和总生物碱的研究%Separation and Purification of Total Flavonoid and Total Alkaloid from Leonurus japonicus with SP825 Macroporous Resin

    Institute of Scientific and Technical Information of China (English)

    李雪丽; 李静雅; 刘晓芳; 朱丹

    2012-01-01

    Objective: To study an effective separation and purification method of total flavonoids and total alkaloids from Leonurus japonicus.Method: 70% ethanol was used to extract fully,and then the concentrated extract was loaded on the top of SP825 Macroporous Resin column.First,the column was eluting with distilled water from which we got the total alkaloids;then eluting with 60% ethanol eluted,the 60% ethanol-eluted fractions were collected and from which got the total flavonoids.Al(NO3)3 complexometric colorimetry and Reinecke colorimetry were adopted respectively to determine the the content of total flavonoids and total alkaloids.Result: The content of total flavonoids was 21.35%,the yield was 64.17%;the content of total alkaloids was 25.65%,the yield was 65.98%.Conclusion: SP825 Macroporous Resin could enrich the total flavonoids from Herba Leonuri effectively,moreover,the content and yield of total alkaloids which were separating from the distilled water-eluted fractions are relatively high.The method is simple and cost-effective,in addition,the utilization of Leonurus japonicus are improved.%本文旨在寻找一种能够同时有效分离纯化益母草总黄酮和总生物碱有效部位的方法.即,采用SP825大孔吸附树脂富集益母草总黄酮,收集水洗脱液,分离纯化得到总生物碱;60%乙醇洗脱得到总黄酮,分别采用比色法于可见分光光度计测定样品总黄酮和总生物碱含量.结果发现:总黄酮含量为21.35%,收率为64.17%;总生物碱含量为25.65%,收率为65.98%.从而证实:SP825大孔吸附树脂能够有效富集益母草总黄酮,同时,从水洗脱液分离纯化得到的总生物碱有效部位含量和收率均较高.该方法经济节省,操作简便,并且提高了药材的使用率.

  1. Preparation and in vitro evaluation of ethosomal total alkaloids of Sophora alopecuroides loaded by a transmembrane pH-gradient method.

    Science.gov (United States)

    Zhou, Yan; Wei, Yuhui; Liu, Huanxiang; Zhang, Guoqiang; Wu, Xin'an

    2010-09-01

    A novel transmembrane pH gradient active loading method to prepare alkaloids binary ethosomes was developed in this work. Using this novel method, binary ethosomes containing total alkaloids extracted from Sophora alopecuroides (TASA) were prepared successfully at the temperature below the phase transition temperature (Tc) of the phosphatidyl choline (PC). Several factors affecting this method were investigated. The qualities of the TASA binary ethosomes were characterized by the shape, particle size, and encapsulation efficiency (EE). The percutaneous absorption study of TASA binary ethosomes was performed using confocal laser scanning microscopy and Franz diffusion cells. The results showed that more than 90% sophoridine, 47% matrine, 35% sophocarpine, and 32% lemannine in TASA were entrapped within 1 h at 40°C, with an efficiency improvement of 8.87, 8.10, 7.63, and 7.78-fold than those observed in passive loading method. Transdermal experiments showed that the penetration depth and fluorescence intensity of Rhodamine B from binary ethosome prepared by pH gradient active loading method were much greater than that from binary ethosome prepared by passive loading method or hydroalcoholic solution. These results suggested transmembrane pH gradient active loading method may be an effective method to prepare alkaloids ethosomal systems at the temperatures below the Tc of PC.

  2. Hypolipidemic Effects of Alkaloids from Rhizoma Coptidis in Diet-Induced Hyperlipidemic Hamsters.

    Science.gov (United States)

    He, Kai; Kou, Shuming; Zou, Zongyao; Hu, Yinran; Feng, Min; Han, Bing; Li, Xuegang; Ye, Xiaoli

    2016-05-01

    This study was conducted to evaluate the antihyperlipidemic activity of five major alkaloids in Rhizoma Coptidis using high-fat- and high-cholesterol-induced hyperlipidemic hamsters. Hyperlipidemic hamsters were treated with coptisine, berberine, jatrorrhizine, palmatine, epiberberine, and total Rhizoma Coptidis alkaloids with a dose of 46.7 mg/kg × day for 140 days. Serum total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total bile acids were examined after alkaloid treatment. The results showed that all therapy agents prevented body weight gain, reduced the serum total cholesterol, and increased the high-density lipoprotein cholesterol of hamsters. Berberine, jatrorrhizine, and total Rhizoma Coptidis alkaloids decreased the triglyceride level in hyperlipidemic hamsters, while coptisine, jatrorrhizine, palmatine, and total Rhizoma Coptidis alkaloids significantly suppressed the elevation of the low-density lipoprotein cholesterol level. The fecal excretion of bile acids was significantly elevated by berberine, coptisine, jatrorrhizine, palmatine, total Rhizoma Coptidis alkaloids, and orlistat. Notably, total Rhizoma Coptidis alkaloids possess a much stronger lipid-lowering effect than the pure Rhizoma Coptidis alkaloids. Quantitative reverse transcription-polymerase chain reaction analyses revealed that Rhizoma Coptidis alkaloids could retard the synthesis of cholesterol by downregulating the mRNA expression of 3-hydroxy-3-methyl glutaryl coenzyme A reductase and accelerate the clearance of lipids by upregulating the low-density lipoprotein receptor, cholesterol 7α-hydroxylase, and uncoupling protein-2 expression. These findings highlight the critical role of Rhizoma Coptidis alkaloids in hyperlipidemia treatment. Thus, they need to be considered in future therapeutic approaches. PMID:26848702

  3. The synthesis of 3H-putrescine and subsequent biosynthesis of 3H-jacobine, a pyrrolizidine alkaloid from Senecio jacobaea

    International Nuclear Information System (INIS)

    A new method was developed for the preparation of tritiated putrescine dihydrochloride ([2,3-3H]-1,4-diaminobutane dihydro-chloride) from succinonitrile (1,4-butanedinitrile) and 3H2O, with a radiochemical yield of 16%. Tritiated jacobine and other pyrrolizidine alkaloids were then biosynthesized in Senecio jacobaea using 3H-putrescine-2HCl as the precursor with a radiochemical yield of 0.9% into total pyrrolizidine alkaloids. Jacobine accounted for 36% of the total. This synthetic method provides a relatively inexpensive source for the preparation of these labelled compounds. (author)

  4. Study Toward the Total Synthesis of Pyrenophorin

    Directory of Open Access Journals (Sweden)

    Everaldo F. Santos Filho

    2012-06-01

    Full Text Available Macrodiolides are macrocyclic compounds containing two ester groups in a cyclic chain. Of this class of compounds, Pyrenophorin (1 shows antifungal activity, and is produced from the pathogenic fungus Pyrenophora avenae. As this substance, derived from nature, is isolated in small quantities, an asymmetric synthesis using a simple and efficient methodology would be of great interest. The proposed synthetic route starts with the protection of propargyl alcohol 3 using DHP and feldspar as catalyst. Compound 5 obtained in this reaction was then subjected to acid-base reaction between the acetylenic proton and 1 eq. n-BuLi, leading to formation of the acetylide 5A. The 1,2- addition reaction between 5A and g-valerolactone (6 leads to the formation of alkinone 7 in 67% yield. Subsequently, compound 7 was subjected to a ketalization reaction using the same feldspar catalyst. Ketal 8 was formed under concomitant removal of the THP group. The product of this reaction (8 was then submitted to a reduction reaction of the triple bond to form olefin 9 with E configuration. Currently, the conditions for obtaining 10 by oxidation using Jones reagent, are being optimized. Compound 10,    obtained as described, is being subjected to a macrolactonization reaction. Various conditions including the use of enzymes are being studied. In addition, a study involving the enantioselective synthesis of (R,R-(--pyrenophorin, using enzymatic kinetic resolution of the racemic mixture of compound 8, is in progress in the group

  5. Purification of total alkaloids from Croton tiglium L.%巴豆总生物碱的纯化工艺研究

    Institute of Scientific and Technical Information of China (English)

    肖祖平; 曾宝; 李生梅; 唐君苹; 林吉; 赖小平

    2012-01-01

    Objective To determine the technology for purification of total alkaloids from Croton tiglium L. by macroporous resin. Methods Acidic dye colorimetry was used to determine the total alkaloids. The adsorption and desorption performances of HPD400, AB-8, NKA-9, ADS-17 and D101 macroporous resins were compared and purification conditions optimized . Results D101 resin was selected because it was separated most effectively. The concentration of sample solution was 1.5 g o mL-1. The adsorption flow rate was 1.5 BV · h -1. Crude medicinal material to resin was 9:2, then 4 BV water and 4 BV 30% ethanol were used as the eluting solvent to wash the resin, collecting 30% ethanol elution. Conclusion This method is simple and feasible, which can be used to separate and purify total alkaloids from Croton tiglium L..%目的 研究大孔树脂分离纯化巴豆总生物碱的工艺.方法 采用分光光度法测定总生物碱,筛选HPD400、AB-8、NKA-9、ADS-17、D101树脂对巴豆总生物碱的吸附和解吸附能力,并优化分离纯化条件.结果 优选出D101树脂,上样液浓度为生药1.5 g ·mL-1,吸附流速1.5 BV·h-1,药材量∶树脂量=9∶2,4 BV水除杂后用4 BV 30%乙醇冲洗收集目标滤液.结论 该方法简便易行,适合于巴豆总生物碱的分离纯化.

  6. Total synthesis: Towards artificial terpene cyclases

    Science.gov (United States)

    Willot, Matthieu; Christmann, Mathias

    2010-07-01

    The plant-derived sesquiterpene englerin A is a potent inhibitor of several renal cancer cell lines. Two recent total syntheses have utilized cationic gold(I)-complexes to coax readily available open-chain precursors into englerin's challenging oxotricyclic core with enzyme-like precision.

  7. 宽筋藤总生物碱含量测定方法研究%Study on the determination method of total alkaloids in Tinospora sinensis caulis

    Institute of Scientific and Technical Information of China (English)

    迟森森; 韩丹; 刘斌

    2015-01-01

    Objective To establish a method for the determination of total alkaloids in Tinospora sinensis caulis .Method The content of total alkaloids was determined ,and hydrochloric jatrorrhizine was selected as a reference substance .Results Hydrochloric jatrorrhizine had a good linear relationship with the absorbance in the range of 0 .001 1‐0 .006 5 mg · mL-1 and the regression equation was Y=14 .747 X-0 .010 7 (r=0 .999 5) .The average recovery for hydrochloric jatrorrhizine was 100 .4% ,RSD=2 .0% (n=6) .Conclusion The contents determination of the total alkaloids for sixteen batches of medicinal materials showed that the method was easy to operate and accurate ,which could be used for the determination of the total alkaloids in Tinospora sinensis caulis .%目的:建立宽筋藤药材中总生物碱的含量测定方法。方法以盐酸药根碱为对照品,采用紫外‐可见分光光度法测定宽筋藤总生物碱的含量,测定波长为430 nm。结果盐酸药根碱在0.0011~0.0065 mg · mL -1范围内与吸光度呈良好线性关系,回归方程:Y=14.747X-0.0107(r=0.9995)。盐酸药根碱平均回收率为100.4%,RSD=2.0%(n=6)。结论16批宽筋藤药材总生物碱含量测定结果表明,所建立的方法简便、准确,可用于宽筋藤药材总生物碱的含量测定。

  8. Study on the determination method of total alkaloids in Tinospora sinensis caulis%宽筋藤总生物碱含量测定方法研究

    Institute of Scientific and Technical Information of China (English)

    迟森森; 韩丹; 刘斌

    2015-01-01

    Objective To establish a method for the determination of total alkaloids in Tinospora sinensis caulis .Method The content of total alkaloids was determined ,and hydrochloric jatrorrhizine was selected as a reference substance .Results Hydrochloric jatrorrhizine had a good linear relationship with the absorbance in the range of 0 .001 1‐0 .006 5 mg · mL-1 and the regression equation was Y=14 .747 X-0 .010 7 (r=0 .999 5) .The average recovery for hydrochloric jatrorrhizine was 100 .4% ,RSD=2 .0% (n=6) .Conclusion The contents determination of the total alkaloids for sixteen batches of medicinal materials showed that the method was easy to operate and accurate ,which could be used for the determination of the total alkaloids in Tinospora sinensis caulis .%目的:建立宽筋藤药材中总生物碱的含量测定方法。方法以盐酸药根碱为对照品,采用紫外‐可见分光光度法测定宽筋藤总生物碱的含量,测定波长为430 nm。结果盐酸药根碱在0.0011~0.0065 mg · mL -1范围内与吸光度呈良好线性关系,回归方程:Y=14.747X-0.0107(r=0.9995)。盐酸药根碱平均回收率为100.4%,RSD=2.0%(n=6)。结论16批宽筋藤药材总生物碱含量测定结果表明,所建立的方法简便、准确,可用于宽筋藤药材总生物碱的含量测定。

  9. Structural investigation of heteroyohimbine alkaloid synthesis reveals active site elements that control stereoselectivity.

    Science.gov (United States)

    Stavrinides, Anna; Tatsis, Evangelos C; Caputi, Lorenzo; Foureau, Emilien; Stevenson, Clare E M; Lawson, David M; Courdavault, Vincent; O'Connor, Sarah E

    2016-01-01

    Plants produce an enormous array of biologically active metabolites, often with stereochemical variations on the same molecular scaffold. These changes in stereochemistry dramatically impact biological activity. Notably, the stereoisomers of the heteroyohimbine alkaloids show diverse pharmacological activities. We reported a medium chain dehydrogenase/reductase (MDR) from Catharanthus roseus that catalyses formation of a heteroyohimbine isomer. Here we report the discovery of additional heteroyohimbine synthases (HYSs), one of which produces a mixture of diastereomers. The crystal structures for three HYSs have been solved, providing insight into the mechanism of reactivity and stereoselectivity, with mutation of one loop transforming product specificity. Localization and gene silencing experiments provide a basis for understanding the function of these enzymes in vivo. This work sets the stage to explore how MDRs evolved to generate structural and biological diversity in specialized plant metabolism and opens the possibility for metabolic engineering of new compounds based on this scaffold. PMID:27418042

  10. First total synthesis of (±)-abyssinoflavanone V

    Institute of Scientific and Technical Information of China (English)

    Jin Hui Yang; Yan Min Zhao; Cong Bin Ji

    2008-01-01

    The total synthesis of (±)-abyssinoflavanone V was first achieved through C-prenylation, selective protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap 4-hydroxybenzaldehyde and 2,4,6-trihydroxyacetophenone, with total yield 24%. All structures of new compounds were confirmed by IR, 1H NMR and MS.

  11. First total synthesis of (±)-sepicanin A

    Institute of Scientific and Technical Information of China (English)

    Jin Hui Yang; Wen Qian Huang; Jun Shan Luo; Dong Dong Guo; Yu Heng Zhang; Hong Jun Li

    2012-01-01

    A facile approach for the first total synthesis of naturally occurring geranylated flavanoids sepicanin A has been obtained with total yield 16% starting from 2,4,6-trihydroxyacetophenone after four steps.The key step was the protic acids (HCl or p-TsOH)-catalyzed benzopyrone formation in a protic polar solvent by deprotection and cyclization of chalcone in one step.

  12. Total synthesis and stereochemical revision of (+)-aeruginosin 298-A.

    Science.gov (United States)

    Wipf, P; Methot, J L

    2000-12-28

    [structure:see text] Novel routes toward both enantiomers of the bicyclic proline surrogate 2-carboxy-6-hydroxyoctahydroindole, i.e., Choi, were developed on the basis of the oxidative cyclization of L-tyrosine. Synthesis of the proposed sequence of (+)-aeruginosin 298-A did not provide the natural product. Incorporation of a D-leucine residue, in contrast, led to the total synthesis of this thrombin inhibitor. PMID:11150202

  13. Total Synthesis and Absolute Configuration of the Marine Norditerpenoid Xestenone

    Directory of Open Access Journals (Sweden)

    Hiroaki Miyaoka

    2009-11-01

    Full Text Available Xestenone is a marine norditerpenoid found in the northeastern Pacific sponge Xestospongia vanilla. The relative configuration of C-3 and C-7 in xestenone was determined by NOESY spectral analysis. However the relative configuration of C-12 and the absolute configuration of this compound were not determined. The authors have now achieved the total synthesis of xestenone using their developed one-pot synthesis of cyclopentane derivatives employing allyl phenyl sulfone and an epoxy iodide as a key step. The relative and absolute configurations of xestenone were thus successfully determined by this synthesis.

  14. Optimization of Supercritical Fluid Extraction of Total Alkaloids, Peimisine, Peimine and Peiminine from the Bulb of Fritillaria thunbergii Miq, and Evaluation of Antioxidant Activities of the Extracts

    Directory of Open Access Journals (Sweden)

    Xiao Ruan

    2016-06-01

    Full Text Available Supercritical fluid extraction (SFE was used to extract total alkaloids, peimisine, peimine and peiminine from the bulb of Fritillaria thunbergii Miq. The antioxidant capacity of the extracts was evaluated by DPPH radical scavenging activity (DPPH-RSA, ABTS radical scavenging activity (ABTS-RSA and ferric reducing capacity (FRAP assay. A central composite design (CCD with four variables and five levels was employed for optimization of process parameters, and response surface plots were constructed in accordance with a second order polynomial model. Under optimal conditions of 3.0 h, 60.4 °C, 26.5 MPa and 89.3% ethanol, the highest yields were predicted to be 3.8 mg/g for total alkaloids, 0.5 mg/g for peimisine, 1.3 mg/g for peimine and 1.3 mg/g for peiminine, and the antioxidant capacity of extracts displayed EC50, DPPH value of 5.5 mg/mL, EC50, ABTS value of 0.3 mg/mL and FRAP value of 118.2 mg ascorbic acid equivalent (AAE/100 g.

  15. Study On Extraction Processes Of Total Alkaloids From Ramulus Uncariae Cum Uncis%钩藤总生物碱提取工艺研究

    Institute of Scientific and Technical Information of China (English)

    窦月; 周洪雷; 蔡梅超; 查慧敏

    2011-01-01

    目的:优选钩藤总生物碱的提取工艺.方法:以钩藤总碱含量和提取液千膏率为综合评价指标,对乙醇用量、浓度、提取时间及次数四因素进行正交考察.结果:钩藤总碱的最佳提取工艺为10倍量75%乙醇提取3次,提取时间2h.结论:提取工艺可稳定可行.%Objective: Investigate the best extract artwork of expressed total alkaloids from Ramulus Uncariae Cum Uncis. Methods: The orthogonal design was adopted with extractive yield and the content of total alkaloids as indices. Four factors were studied in this experiment, including the alcohol consumption, alcohol concentration, time of extraction, and times of extraction. Results:The best extract process is extract 3 times with 10 times 75% alcohol,each time for 2h. Conclusion:This extract process is stable and feasible.

  16. Mechanism of Lipid-Lowering Effect of Paniculata Total Alkaloids%布渣叶总生物碱降血脂作用机制研究

    Institute of Scientific and Technical Information of China (English)

    冯亮

    2015-01-01

    目的 探讨布渣叶总生物碱降血脂作用机制研究. 方法 采用高脂饲料构建高脂血症的大鼠动物模型, 采用灌胃的形式给予不同浓度的布渣叶总生物碱, 通过检测大鼠载脂蛋白、 相关酶类及活性物质, 初步探讨布渣叶总生物碱的降脂作用机制. 结果 布渣叶总生物碱可升高载脂蛋白AI ( ApoAI) , ApoAI/载脂蛋白B ( ApoB) 的比值, 与模型组相比差异具有统计学意义 (P<0. 05); 提高超氧化物歧化酶 (SOD) 的活性, 降低丙二醛 (MDA) 的含量, 与模型组相比差异具有统计学意义 (P<0. 05); 提高卵磷脂胆固醇酰基转移酶 (LCAT) 的活性, 提高一氧化氮 (NO) 的水平, 降低C反应蛋白 (CRP), 且组间相比具有统计学差异 (P<0. 05). 结论 布渣叶总生物碱通过升高高密度脂蛋白胆固醇升高ApoAI, 激活LCAT, 从而促进胆固醇的逆转运, 提高SOD活性, 增强机体康脂质过氧化能力, 促进NO生成, 改善血管内皮功能,具有从多方位调节血脂的作用.%Objective To investigate the mechanism of lipid-lowering effect of paniculata total alkaloids. Methods Animal models of hyperlipidemia rats were constructed by using the high-fat diet. Different concentrations of paniculata total alkaloids were ad-ministered in the form of gavage. Lipid-lowering effect of paniculata total alkaloids was studied by detecting rat apolipoprotein, associ-ated enzymes and active substances. Results The paniculata total alkaloids increased apolipoprotein AI ( ApoAI) , ApoAI / ratio of apolipoprotein B (ApoB). There was statistically significant difference compared with that of the model group (P<0. 05), it also in-creased superoxide dismutase ( SOD) activity and decreased malondialdehyde ( MDA) content. They were significantly different com-pared with those of the model group (P<0. 05), it improved lecithin cholesterol acyltransferase (LCAT) activity, increased Nitric ox-ide (NO) levels and reduced C-reactive protein

  17. A comparative study on analytical method of total alkaloids from cortex Phellodendri amurens by reversed phase high performance liquid chromatography (RP-HPLC and pressurized capillary electrochromatography (pCEC

    Directory of Open Access Journals (Sweden)

    Bo Yang

    2011-02-01

    Full Text Available A pressurized capillary electrochromatography (pCEC method with post-column detection cell has been developed for the analysis of total alkaloids of cortex Phellodendron amurense Rupr., Rutaceae. The separation of total alkaloids (berberine, palmatine, oatrorrhizine, magnoflorine, phellodendrine, candicine, menisperine was optimized by compositions of the mobile phase, ionic strength of buffers, pH value, and applied voltage. Separation of total alkaloids was achieved within 11 min by using a mobile phase of Na2HPO4-citric acid solution-acetonitrile (pH 4.00; 3 mM (60:40, v/v and applying a voltage of -10 kV. This method showed satisfactory retention times and peak shapes. Meanwhile, a reversed phase high performance liquid chromatography (RP-HPLC has also been established for the separation of total alkaloids extracted from cortex Phellodendri amurens. Baseline separation of total alkaloids was achieved within 25 min by using a mobile phase of acetonitrile-0.1% phosphoric acid with 0.1 g sodium dodecanesulphonate per 100 mL (35:65, v/v. Compared to conventional RP-HPLC, pCEC led to higher column efficiency, less consumption of reagent, and shorter analysis time.

  18. Crystal structure of norcoclaurine-6-O-methyltransferase, a key rate-limiting step in the synthesis of benzylisoquinoline alkaloids.

    Science.gov (United States)

    Robin, Adeline Y; Giustini, Cécile; Graindorge, Matthieu; Matringe, Michel; Dumas, Renaud

    2016-09-01

    Growing pharmaceutical interest in benzylisoquinoline alkaloids (BIA) coupled with their chemical complexity make metabolic engineering of microbes to create alternative platforms of production an increasingly attractive proposition. However, precise knowledge of rate-limiting enzymes and negative feedback inhibition by end-products of BIA metabolism is of paramount importance for this emerging field of synthetic biology. In this work we report the structural characterization of (S)-norcoclaurine-6-O-methyltransferase (6OMT), a key rate-limiting step enzyme involved in the synthesis of reticuline, the final intermediate to be shared between the different end-products of BIA metabolism, such as morphine, papaverine, berberine and sanguinarine. Four different crystal structures of the enzyme from Thalictrum flavum (Tf 6OMT) were solved: the apoenzyme, the complex with S-adenosyl-l-homocysteine (SAH), the complexe with SAH and the substrate and the complex with SAH and a feedback inhibitor, sanguinarine. The Tf 6OMT structural study provides a molecular understanding of its substrate specificity, active site structure and reaction mechanism. This study also clarifies the inhibition of Tf 6OMT by previously suggested feedback inhibitors. It reveals its high and time-dependent sensitivity toward sanguinarine.

  19. Total Synthesis of Three New Dihydrostilbenes from Bulbophllum odoratissimum

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A total synthesis of three new dihydrostilbenes, 1, 2 and 3, which were isolated from Bulbophyllum odoratissimum Lindl. with significant cytotoxicity toward human cancer cell lines,was developed via Horner reaction etc. The natural products 1, 2 and 3 were obtained in 5.8%,6.6% and 5.9%, respectively.

  20. The First Total Synthesis of Triprenylquinone and Hydroquinones

    Institute of Scientific and Technical Information of China (English)

    Chun Hong LI; Xue Song CHEN; Guang Lian ZHOU; Zhi Xiang XIE; Ying LI

    2005-01-01

    First total synthesis of triprenylquinone and hydroquinones, three naturally occurring compound 1, 2 and (±) 3, have been achieved from readily available 2-bromo-5-methyl-1,4-dimethoxybenzene 4 and geranyl bromide. The triprenylquinone and hydroquinones precursor were readily prepared with use of a Julia reaction.

  1. Expedient total synthesis of pyrrothine natural products and analogs

    DEFF Research Database (Denmark)

    Hjelmgaard, Thomas; Givskov, Michael Christian; Nielsen, John

    2007-01-01

    This paper describes an expedient and straightforward total synthesis of the two pyrrothine natural products holomycin (7 steps, 11% overall) and xenorhabdin I (7 steps, 11% overall) and analogs thereof via a common late-stage intermediate. The pathway proceeds via the pyrrothine hydrochloride...

  2. Enantioselective Total Synthesis of the (+) Antipode of Zeylenone

    Institute of Scientific and Technical Information of China (English)

    An LIU; Zhan Zhu LIU; Zhong Mei ZOU; Shi Zhi CHEN; Li Zhen XU; Shi Lin YANG

    2004-01-01

    Starting from shikimic acid, the total synthesis of zeylenone was studied. The product was proved to be the (+)antipode of zeylenone through analysis and comparison of their respective spectra (including NMR, MS, IR and CD) and optical data. The absolute configuration of the natural product was thus determined to be (1 S,2S,3R).

  3. The total synthesis of 3b-hydroxynagilactone F

    NARCIS (Netherlands)

    Reuvers, J.T.A.

    1985-01-01

    The investigations described in this thesis deal with the total synthesis of physiologically active nor- and bisnorditerpenoid dilactones (fig.1).The goal was to design a synthetic route for this class of natural products and its derivatives. From a retrosynthe

  4. Study on quality control of total alkaloids in Ramulus Uncariae Cum Uncis%钩藤总生物碱有效部位质量控制研究

    Institute of Scientific and Technical Information of China (English)

    蒋海强; 窦月; 周洪雷

    2012-01-01

    Objective:To establish the method for quality control of total alkaloids in Ramulus Uncariae Cum Uncis. Methods;The contents of total alkaloids were determined by acid dye colorimetry,HPLC was used to measure the contents of rhynchophylline and fingerprint of total alkaloids in Ramulus Uncariae Cum Uncis. Results:The contents of total alkaloids were higher than 50%,the linear range of rhynchopHylline was 5.75-92 μg/mL,the average recovery was 98.82%. The chemical composition of different batches total alkaloids in Ramulus Uncariae Cum Uncis was difference by fingerprint similarity evaluation. Conclution:The method can be used for quality control of total alkaloids in Ramulus Uncariae Cum Uncis.%目的:建立钩藤总生物碱有效部位质量控制方法.方法:采用酸性染料染色法测定钩藤总生物碱的含量,采用高效液相色谱法测定有效部位中钩藤碱的含量,采用高效液相色谱法建立钩藤总生物碱有效部位的指纹图谱.结果:钩藤总生物碱的含量均在50%以上,钩藤碱在5.75~ 92 μg/mL之间线性关系良好,平均回收率为98.82%,通过指纹图谱相似度评价,不同批次的钩藤总生物碱有效部位的化学成分存在差异.结论:本研究建立的质量控制方法可有效控制钩藤总生物碱有效部位的质量.

  5. Extraction of Total Alkaloids from Corydalis saxicola Bunting by Enzymatic Method%酶法提取岩黄连总生物碱的研究

    Institute of Scientific and Technical Information of China (English)

    李倩霞; 赵青; 蒋林; 杨得坡; 陈建萍; 王冬梅

    2009-01-01

    目的 研究植物提取酶在提取岩黄连总生物碱中的应用.方法 岩黄连药材经酶处理后用乙醇回流提取总生物碱,通过正交实验优化酶处理工艺参数.结果 酶解反应的最佳工艺条件为:温度45℃、酶反应时间16 h、pH 5.0、酶用量0.9%.结论 药材经酶处理后再用乙醇回流提取,对总生物碱的提取率比传统的直接乙醇回流提取法的提取率提高约24%,适用于岩黄连总生物碱的辅助提取.%Objection To study the extraction of total alkaloids from Corydalis saxicola Bunting by enzymatic method. Methods C. saxicola was treated by enzyme before refluxed with 60% ethanol aqueous solution, and the parameters of enzymatic hydrolysis was optimized by an orthogonai experiment. Results The optimum enzymatic hydrolysis conditions were determined as follows: temperature was 45℃ , reaction time was 16 h, pH value of the buffer solution was 5.0 and 0.9% of enzyme amount. Conclusion The yield of total alkaloids extracted from C. saxicola with pretreatment by enzymatic hydrolysis increased about 24% than that of without enzymatic hydrolysis pretreatment. Enzymatic hydrolysis could be applied as an assistant for the extraction of total alkoids from C. saxicola.

  6. Asymmetric Total Synthesis of a Diastereisomer A of Tuxpanolide

    Institute of Scientific and Technical Information of China (English)

    WANG,Jin-Xin; ZHANG,Chao-Xin; LI,Ying

    2004-01-01

    @@ α-Alkylidene-β-hydroxy butyrolactones have been attractive and challenging targets for organic synthesis in various laboratories because that not only they are rich in skeletal diversity and stereochemistry complexity but also many of them possess quite intriguing and wide biological activities.[1] A novel class of the phytane-type diterpenoid named Tuxpanolide, bearing α-alkylidene-β-hydroxy-γ-butyrolactone skeleton, was isolated from Perymenium hintonii in Central Mexico by Maldonado and co-wokers in 1998.[2] Now we firstly report the efficient strategy of the stereocontrolled total synthesis of a diastereisomer A of Tuxpanolide.

  7. Total Synthesis of Putative 11-epi-Lyngbouilloside Aglycon.

    Science.gov (United States)

    Kolleth, Amandine; Gebauer, Julian; ElMarrouni, Abdelatif; Lebeuf, Raphael; Prévost, Céline; Brohan, Eric; Arseniyadis, Stellios; Cossy, Janine

    2016-01-01

    We report here the total synthesis of 11-epi-lyngbouilloside aglycon. Our strategy features a Boeckman-type esterification followed by a RCM to form the 14-membered ring macrolactone and a late-stage side chain introduction via a Wittig olefination. Overall, the final product was obtained in 20 steps and 2% overall yield starting from commercially available 3-methyl-but-3-enol. Most importantly, the strategy employed is versatile enough to eventually allow us to complete the synthesis of the natural product and irrevocably confirm its structure. PMID:27556024

  8. Catalytic Asymmetric Total Synthesis of Hedyosumins A, B, and C.

    Science.gov (United States)

    Sun, Wang-Bin; Wang, Xuan; Sun, Bing-Feng; Zou, Jian-Ping; Lin, Guo-Qiang

    2016-03-18

    The first and asymmetric total synthesis of hedyosumins A, B, and C was accomplished in 13-14 steps from simple starting materials. The essential tools that allow us to access the tetracyclic skeleton include an organocatalytic [4 + 3] cycloaddition reaction, an intramolecular aldol condensation, and an intramolecular carboxymercuration/demercuration enabled lactonization. A CBS-catalyzed asymmetric reduction was employed to boost the ee of the synthetic natural products to an excellent level. This synthesis established the absolute configurations of hedyosumins A, B, and C. PMID:26925758

  9. Total Synthesis of Putative 11-epi-Lyngbouilloside Aglycon

    Science.gov (United States)

    Kolleth, Amandine; Gebauer, Julian; ElMarrouni, Abdelatif; Lebeuf, Raphael; Prévost, Céline; Brohan, Eric; Arseniyadis, Stellios; Cossy, Janine

    2016-01-01

    We report here the total synthesis of 11-epi-lyngbouilloside aglycon. Our strategy features a Boeckman-type esterification followed by a RCM to form the 14-membered ring macrolactone and a late-stage side chain introduction via a Wittig olefination. Overall, the final product was obtained in 20 steps and 2% overall yield starting from commercially available 3-methyl-but-3-enol. Most importantly, the strategy employed is versatile enough to eventually allow us to complete the synthesis of the natural product and irrevocably confirm its structure. PMID:27556024

  10. Vinca Alkaloids

    Directory of Open Access Journals (Sweden)

    Maryam Moudi

    2013-01-01

    Full Text Available Vinca alkaloids are a subset of drugs obtained from the Madagascar periwinkle plant. They are naturally extracted from the pink periwinkle plant, Catharanthus roseus G. Don and have a hypoglycemic as well as cytotoxic effects. They have been used to treat diabetes, high blood pressure and have been used as disinfectants. The vinca alkaloids are also important for being cancer fighters. There are four major vinca alkaloids in clinical use: Vinblastine (VBL, vinorelbine (VRL, vincristine (VCR and vindesine (VDS. VCR, VBL and VRL have been approved for use in the United States. Vinflunine is also a new synthetic vinca alkaloid, which has been approved in Europe for the treatment of second-line transitional cell carcinoma of the urothelium is being developed for other malignancies. Vinca alkaloids are the second-most-used class of cancer drugs and will stay among the original cancer therapies. Different researches and studies for new vinca alkaloid applications will be carried out in this regard.

  11. Total Synthesis of Six 3,4-Unsubstituted Coumarins

    Directory of Open Access Journals (Sweden)

    Wenqing Gao

    2013-12-01

    Full Text Available In this article we describe a new methodology for the total synthesis of 3,4-unsubstituted coumarins from commercially available starting materials. Six examples were prepared, including five naturally occurring coumarins—7-hydroxy-6,8-dimethoxy-coumarin (isofraxidin, 7-hydroxy-6-methoxycoumarin (scopoletin, 6,7,8-trimethoxy-coumarin, 6,7-dimethoxycoumarin (scoparone, and 7,8-dihydroxycoumarin (daphnetin and one synthetic coumarin, 7-hydroxy-6-ethoxycoumarin. Moreover, five important o-hydroxybenzaldehyde intermediates were also obtained, namely 2,4-dihydroxy-3,5-dimethoxybenzaldehyde, 2,4-dihydroxy-5-methoxybenzaldehyde, 5-ethoxy-2,4-dihydroxy-benzaldehyde, 2-hydroxy-3,4,5-trimethoxybenzaldehyde, and 2-hydroxy-4,5-dimethoxy-benzaldehyde. The method developed herein involves just three or four steps and allows for the rapid synthesis of these important molecules in excellent yields. This is the first synthesis of 6,7,8-trimethoxycoumarin and 7-hydroxy-6-ethoxycoumarin.

  12. Short, Enantioselective Total Synthesis of Highly Oxidized Taxanes.

    Science.gov (United States)

    Yuan, Changxia; Jin, Yehua; Wilde, Nathan C; Baran, Phil S

    2016-07-11

    In the realm of natural product chemistry, few isolates have risen to the level of fame justifiably accorded to Taxol (1) and its chemical siblings. This report describes the most concise route to date for accessing the highly oxidized members of this family. As representative members of taxanes containing five oxygen atoms, decinnamoyltaxinine E (2) and taxabaccatin III (3), have succumbed to enantioselective total synthesis for the first time in only 18 steps from a simple olefin starting material. The strategy holistically mimics nature's approach (two-phase synthesis) and features a carefully choreographed sequence of stereoselective oxidations and a remarkable redox-isomerization to set the key trans-diol present in 2 and 3. This work lays the critical groundwork necessary to access even higher oxidized taxanes such as 1 in a more practical fashion, thus empowering a medicinal chemistry campaign that is not wedded to semi-synthesis. PMID:27240325

  13. Investigation of free amino acid, total phenolics, antioxidant activity and purine alkaloids to assess the health properties of non-Camellia tea

    Directory of Open Access Journals (Sweden)

    Wu Bi

    2016-03-01

    Full Text Available To find novel functional beverages from folk teas, 33 species of frequently used non-Camellia tea (plants other than Camellia were collected and compared with Camellia tea (green tea, pu-erh tea and black tea for the first time. Data are reported here on the quantities of 20 free amino acids (FAAs and three purine alkaloids (measured by UHPLC, total polyphenols (measured by Folin-Ciocalteu assay, and antioxidant activity (DPPH. The total amounts of FAAs in non-Camellia tea (0.62–18.99 mg/g are generally less than that of Camellia tea (16.55–24.99 mg/g. However, for certain FAAs, the quantities were much higher in some non-Camellia teas, such as γ-aminobutyric acid in teas from Ampelopsis grossedentata, Isodon serra and Hibiscus sabdariffa. Interestingly, theanine was detected in tea from Potentilla fruticosa (1.16±0.81 mg/g. Furthermore, the content of polyphenols in teas from A. grossedentata, Acer tataricum subsp. ginnala are significantly higher than those from Camellia tea; teas from I. serra, Pistacia chinensis and A. tataricum subsp. ginnala have remarkable antioxidant activities similar to the activities from green tea (44.23 μg/mL. Purine alkaloids (caffeine, theobromine and theophylline were not detected in non-Camellia teas. The investigation suggest some non-Camellia teas may be great functional natural products with potential for prevention of chronic diseases and aging, by providing with abundant polyphenols, antioxidants and specific FAAs.

  14. Investigation of free amino acid, total phenolics, antioxidant activity and purine alkaloids to assess the health properties of non-Camellia tea.

    Science.gov (United States)

    Bi, Wu; He, Chunnian; Ma, Yunyun; Shen, Jie; Zhang, Linghua Harris; Peng, Yong; Xiao, Peigen

    2016-03-01

    To find novel functional beverages from folk teas, 33 species of frequently used non-Camellia tea (plants other than Camellia) were collected and compared with Camellia tea (green tea, pu-erh tea and black tea) for the first time. Data are reported here on the quantities of 20 free amino acids (FAAs) and three purine alkaloids (measured by UHPLC), total polyphenols (measured by Folin-Ciocalteu assay), and antioxidant activity (DPPH). The total amounts of FAAs in non-Camellia tea (0.62-18.99 mg/g) are generally less than that of Camellia tea (16.55-24.99 mg/g). However, for certain FAAs, the quantities were much higher in some non-Camellia teas, such as γ-aminobutyric acid in teas from Ampelopsis grossedentata, Isodon serra and Hibiscus sabdariffa. Interestingly, theanine was detected in tea from Potentilla fruticosa (1.16±0.81 mg/g). Furthermore, the content of polyphenols in teas from A. grossedentata, Acer tataricum subsp. ginnala are significantly higher than those from Camellia tea; teas from I. serra, Pistacia chinensis and A. tataricum subsp. ginnala have remarkable antioxidant activities similar to the activities from green tea (44.23 μg/mL). Purine alkaloids (caffeine, theobromine and theophylline) were not detected in non-Camellia teas. The investigation suggest some non-Camellia teas may be great functional natural products with potential for prevention of chronic diseases and aging, by providing with abundant polyphenols, antioxidants and specific FAAs. PMID:27006902

  15. Enantioselective synthesis of 1,2,4-triazolines catalyzed by a cinchona alkaloid-derived organocatalyst.

    Science.gov (United States)

    Shao, Qian; Chen, Jiean; Tu, Meihua; Piotrowski, David W; Huang, Yong

    2013-12-01

    An enantioselective organocatalytic process for the one-step synthesis of poly-substituted 1,2,4-triazolines is reported. The heterocycle formation is believed to go through a step-wise mechanism of nucleophilic addition of an azlactone to an azodicarboxylate in the presence of an organic base catalyst, followed by a TMSCHN2 mediated heterocyclization. Both theoretical calculations and experimental evidence suggest the pre-organization of the transition state for the chirality determining step via a unique 7-membered intramolecular hydrogen bonding. PMID:24145477

  16. Xenicane Natural Products: Biological Activity and Total Synthesis.

    Science.gov (United States)

    Betschart, Leo; Altmann, Karl-Heinz

    2015-01-01

    The xenicanes are a large class of mostly bicyclic marine diterpenoids featuring a cyclononane ring as a common structural denominator. After a brief introduction into the characteristic structural features of xenicanes and some biogenetic considerations, the major focus of this review will be on the various biological activities that have been reported for xenicanes and on efforts towards the total synthesis of these structures. Several xenicanes have been shown to be potent antiproliferative agents in vitro, but activities have also been reported in relation to inflammatory processes. However, so far, data on the possible in vivo activity of xenicanes are lacking. The major challenge in the total synthesis of xenicanes is the construction of the nine-membered ring. Different strategies have been pursued to establish this crucial substructure, including Grob fragmentation, ring-closing olefin metathesis, or Suzuki cross coupling as the enabling transformations. PMID:26429717

  17. Total synthesis of an oxepine natural product, (±)-janoxepin.

    Science.gov (United States)

    Doveston, Richard G; Steendam, René; Jones, Stuart; Taylor, Richard J K

    2012-02-17

    The total synthesis of (±)-janoxepin, a novel antiplasmodial d-leucine derived oxepine-pyrimidinone-ketopiperazine isolated from the fungus Aspergillus janus, is described. The cornerstones of the synthetic route are pyrimidinone preparation, ring-closing metathesis, aldol introduction of the enamide, and dihydro-oxepine elaboration. This synthetic route proved very efficient for the formation of a number of janoxepin analogues, including dihydro-janoxepin and tetrahydro-janoxepin. PMID:22288766

  18. Total synthesis and development of bioactive natural products

    OpenAIRE

    TATSUTA, Kuniaki

    2008-01-01

    The first total synthesis and development of a variety of bioactive natural products have been accomplished by using carbohydrates as a chiral source. In addition, practically useful intermediates have been created, analogs of natural products have been prepared, their structure-activity relationships studied, and the large-scale preparations of medicinally useful compounds established. The key target molecules have been the “Big Four” antibiotics (macrolides, aminoglycosides, β-lactams and t...

  19. First total synthesis of two nematicidal prenylated flavanones

    Institute of Scientific and Technical Information of China (English)

    Jin Hui Yang; Shi Zhi Jiang; Yan Min Zhao; Yun Feng Li; Cong Bin Ji; Wan Yi Liu

    2009-01-01

    The total synthesis of(±)-8-(3-methylbut-2-enyl)-2-phenyl-2,3-dihydrochromen-4-one and(±)-2-(4-hydroxyphenyl)-8-(3-methylbut-2-enyl)-2,3-dihydrochromen-4-one was first achieved through C-prenylation,protection of phenolic hydroxyl group,aldol condensation,cyclization and deprotection starting from cheap benzaldehyde,4-hydroxybenzaldehyde and 2-hydroxyacetophenone,with total yield of 20 and 16.3%.All structures of new compounds were confirmed by IR,1H NMR and MS.

  20. The alkaloid profiles of Lupinus sulphureus.

    Science.gov (United States)

    Cook, Daniel; Lee, Stephen T; Gardner, Dale R; Pfister, James A; Welch, Kevin D; Green, Benedict T; Davis, T Zane; Panter, Kip E

    2009-02-25

    Lupines are common plants on the rangelands in the western United States. Lupines contain alkaloids that can be toxic and teratogenic causing congenital birth defects (crooked calf disease). One such lupine, Lupinus sulphureus, occurs in parts of Oregon, Washington, and British Columbia. Specimens of L. sulphureus from field collections and herbaria were evaluated taxonomically and by chemical means. A total of seven distinct alkaloid profiles and the individual alkaloids associated with each profile were identified. Each alkaloid profile was unique in its geographical distribution and its potential risk to livestock. In conclusion, taxonomic classification is not sufficient to determine risk, as chemical characterization of the alkaloids must also be performed.

  1. Synthesis of derivatives of tetronic acid and pulvinic acid. Total synthesis of norbadione A

    International Nuclear Information System (INIS)

    When vegetables like mushrooms are contaminated by radioactive caesium 137, this radioactive caesium is associated to norbadione A, a natural pigment present in two mushroom species and which can be used as a caesium decorporation agent or maybe as protection agent against ionizing radiations. Within this perspective, this research report describes the biosynthesis and the structure and properties of the norbadione A and of pulvinic acids (physicochemical properties, anti-oxidizing properties). Then, it presents the various tetronic acids (3-acyl-, 3-alkyl-, 3-alkoxy-, 3-aryl-tetronic acids and non 3-substituted tetronic acids), their synthesis path as they are described in the literature, and presents a new synthesis approach using a tandem reaction (with different esters or hydroxy esters) and the synthesis of tetronic acids. The author also proposes a new synthesis way for methyl pulvinates, and finally reports the work on the development of a total synthesis of the norbadione A

  2. A bio-inspired total synthesis of tetrahydrofuran lignans.

    Science.gov (United States)

    Albertson, Anna K F; Lumb, Jean-Philip

    2015-02-01

    Lignan natural products comprise a broad spectrum of biologically active secondary metabolites. Their structural diversity belies a common biosynthesis, which involves regio- and chemoselective oxidative coupling of propenyl phenols. Attempts to replicate this oxidative coupling have revealed significant challenges for controlling selectivity, and these challenges have thus far prevented the development of a unified biomimetic route to compounds of the lignan family. A practical solution is presented that hinges on oxidative ring opening of a diarylcyclobutane to intercept a putative biosynthetic intermediate. The effectiveness of this approach is demonstrated by the first total synthesis of tanegool in 4 steps starting from ferulic acid, as well as a concise synthesis of the prototypical furanolignan pinoresinol.

  3. Total Synthesis of (-)-Spinosyn A via Carbonylative Macrolactonization.

    Science.gov (United States)

    Bai, Yu; Shen, Xingyu; Li, Yong; Dai, Mingji

    2016-08-31

    Spinosyn A (1), a complex natural product featuring a unique 5,6,5,12-fused tetracyclic core structure, is the major component of spinosad, an organic insecticide and an FDA-approved agent used worldwide. Herein, we report an efficient total synthesis of (-)-spinosyn A with 15 steps in the longest linear sequence and 23 steps total from readily available compounds 14 and 23. The synthetic approach features several important catalytic transformations including a chiral amine-catalyzed intramolecular Diels-Alder reaction to afford 22 in excellent diastereoselectivity, a one-step gold-catalyzed propargylic acetate rearrangement to convert 28 to α-iodoenone 31, an unprecedented palladium-catalyzed carbonylative Heck macrolactonization to form the 5,12-fused macrolactone in one step, and a gold-catalyzed Yu glycosylation to install the challenging β-forosamine. This total synthesis is highly convergent and modular, thus offering opportunities to synthesize spinosyn analogues in order to address the emerging cross-resistance problems. PMID:27510806

  4. First total synthesis of four natural prenylated flavonoids

    Institute of Scientific and Technical Information of China (English)

    Jin Hui Yang; Wu Biao Zuo; Dong Dong Guo; Jun Shan Luo; Wen Qian Huang

    2012-01-01

    A facile approach for the first total synthesis of prenylated flavonoids,(±)-abyssinone-Ⅵ-4-O-methyl ether 1,(±)-abyssinone-Ⅳ-4'-O-methyl ether 2,(±)-abyssinone-Ⅴ-4'-O-methyl ether 3 and (±)-sigmoidin E 4 has been described.The key intermediate 4-hydroxy-3,5-di-(3-methylbut-2-enyl)benzaldehyde 6 was also first synthesized that features regioselective prenylation of 4-hydroxybenzaldehyde and crystallizing with petroleum ether from the reaction mixture by freeze-out effect.

  5. Total Synthesis and Biological Assessment of Mandelalide A.

    Science.gov (United States)

    Brütsch, Tobias Michael; Bucher, Pascal; Altmann, Karl-Heinz

    2016-01-22

    A new convergent total synthesis of the marine macrolide mandelalide A (1) has been developed that is based on macrocyclic ring closure by a Shiina-type macrolactonization and the construction of the requisite precursor seco acid by a highly efficient Sonogashira cross-coupling reaction between two fragments of comparable complexity. Key steps in the elaboration of the acid building block were the enantioselective, catalytic addition of a protected acetylene to crotonaldehyde and the construction of the tetrahydropyran unit that is embedded in the macrocycle by means of an acid-catalyzed Prins reaction. The synthesis of the alcohol fragment features the formation of the trisubstituted tetrahydrofuran ring through an acetal cleavage/epoxide opening cascade reaction and a rarely used radical alkynylation of a primary alkyl iodide. Intriguingly, the dihydroxylation of a terminal double bond as part of the synthesis of this building block gave the same major product for both the α- and β-AD-mix reagents, albeit with moderate or low selectivity. Synthetic mandelalide A (1) was a potent proliferation inhibitor of A549, HT460, and H1299 human lung cancer cells in vitro, but not of SK-N-SH neuroblastoma cells. However, in no case did we observe complete cell kill even at the highest compound concentration tested (5 μm). PMID:26639765

  6. Cobalt-catalyzed diastereoselective synthesis of C-furanosides. Total synthesis of (-)-isoaltholactone.

    Science.gov (United States)

    Nicolas, Lionel; Izquierdo, Eva; Angibaud, Patrick; Stansfield, Ian; Meerpoel, Lieven; Reymond, Sébastien; Cossy, Janine

    2013-12-01

    An array of C-aryl and C-vinyl furanosides were prepared in good yields and diastereoselectivities from C-halogeno furanosides either with aryl Grignard or with vinyl Grignard using the convenient Co(acac)3/TMEDA catalytic system. This method is illustrated by the total synthesis of the (-)-isoaltholactone. PMID:24127819

  7. A Short Synthetic Route to the Calystegine Alkaloids

    DEFF Research Database (Denmark)

    Skaanderup, Philip Robert; Madsen, Robert

    2003-01-01

    An efficient strategy is described for the synthesis of enantiopure calystegine alkaloids. The key step employs a zinc-mediated fragmentation of benzyl-protected methyl 6-iodo-glycosides followed by in situ formation of the benzyl imine and Barbier-type allylation with zinc, magnesium, or indium ...... to afford the desired calystegines. Hereby, calystegine B2, B3, and B4 are prepared from D-glucose, D-galactose, and D-mannose, respectively. This route constitutes the shortest synthesis of calystegine B2 and gives rise to the first total syntheses of calystegine B3 and B4....

  8. 半夏与钩藤生物总碱联合抗惊厥作用及毒性反应的定量评价%Quantitative evaluation of the anticonvulsant effects and toxicity of pinellia total alkaloid and uncaria total alkaloid in combination in mice

    Institute of Scientific and Technical Information of China (English)

    张密; 李禄金; 吕映华; 郑青山

    2010-01-01

    目的:利用已发表的半夏生物总碱(pinellia total alkaloid,PTA)与钩藤生物总碱(uncaria total alkaloid,UTA)联合抗惊厥和毒性作用数据,全面定量评价其相互作用和组方合理性.方法:采用等效图法(isobologram)和计算机模拟技术,定量评价不同强度(0%~99%)有效剂量(ED)和致死剂量(LD)的相互作用,并综合计算其获益指数(BI)和治疗指数(TI).结果:3个配比(PTA:UTA=1:4,1:1,4:1)有协同作用趋势.由于最高剂量的有效率均低于70%,给参数计算和研究结论带来不确定性.PTA和UTA按4:1联用的毒性呈现拮抗作用,其它2个配比毒性拮抗作用不明确.基于ED和LD参数的综合分析,3个配比的BI均大于1,其中4:1配比的减毒增效作用明确,TI增大.结论:PTA和UTA按4:1给药后安全性和有效性提高,呈现配伍优势.从方法学角度,本研究可对同类实验的设计和分析提供参考.

  9. 离子交换树脂对钩藤总生物碱的纯化工艺%Purification Technology of Total Alkaloids from Uncaria rhynchophylla by Ion-Exchange Resin

    Institute of Scientific and Technical Information of China (English)

    窦月; 周洪雷; 齐冬梅; 李运伦; 陈凯

    2012-01-01

    Objective: To establish purification technology of total alkaloids from Uncaria rhynchophylla with cation-exchange resin. Method: Total alkaloids from U. Rhynchophylla was selected as indicator, and investigated separation technology conditions of total alkaloids from U. Rhynchophylla by ion-exchange resin. Result:Seven hundred and thirty-two cation-exchange resin was chosen,flow rate of sample was 1 mL·min-1 of flow rate,then eluted with 10 BV water and 6 BV 80% ethanol,finally eluted with 1% aqueous ammonia 80% ethanol, the content of total alkaloids from U. Rhynchophylla was up to 50% . Conclusion: This technology was simply, the content of total alkali was high, suitable for industrial production.%目的:建立阳离子交换树脂纯化钩藤总生物碱的工艺.方法:以钩藤总生物碱为研究指标,考察离子交换树脂分离钩藤总生物碱的工艺条件.结果:选择732型阳离子交换树脂,以1 mL· min -1的流速上样,分别用10 BV水,6 BV 80%乙醇洗脱除杂,最后选用1%氨性80%乙醇洗脱得到钩藤总生物碱,含量达到50%.结论:该方法工艺较简单,总碱含量较高,适合工业化生产.

  10. Indole alkaloids and terpenoids from Tabernaemontana markgrafiana

    DEFF Research Database (Denmark)

    Nielsen, H.B.; Hazell, A.; Hazell, R.;

    1994-01-01

    The bark of Tabernaemontana markgrafiana yielded five acetylated pentacyclic triterpenes and 24 monoterpene indole alkaloids. The major triterpene was baurenyl acetate, which constituted ca 6% of the crude petrol extract. An X-ray study of iso-ursenyl acetate was carried out for the first time....... The indole alkaloids were primarily of the iboga-type and constituted ca 3% of the dried bark and 20% of the total extracts. The major alkaloids were coronaridine, (19S)-heyneanine, voacangine and ibogamine. Among the minor components, four new alkaloids were identified: 5,6-dehydro-coronaridine, 3R...

  11. Direct Synthesis of Protoberberine Alkaloids by Rh-Catalyzed C-H Bond Activation as the Key Step.

    Science.gov (United States)

    Jayakumar, Jayachandran; Cheng, Chien-Hong

    2016-01-26

    A one-pot reaction of substituted benzaldehydes with alkyne-amines by a Rh-catalyzed C-H activation and annulation to afford various natural and unnatural protoberberine alkaloids is reported. This reaction provides a convenient route for the generation of a compound library of protoberberine salts, which recently have attracted great attention because of their diverse biological activities. In addition, pyridinium salt derivatives can also be formed in good yields from α,β-unsaturated aldehydes and amino-alkynes. This reaction proceeds with excellent regioselectivity and good functional group compatibility under mild reaction conditions by using O2 as the oxidant. PMID:26689172

  12. Alkaloids from Delphinium pentagynum.

    Science.gov (United States)

    Díaz, Jesús G; Ruiz, Juan García; Herz, Werner

    2004-07-01

    Aerial parts of a collection of Delphinium pentagynum Lam. from Niebla, Southern Spain, furnished one diterpene alkaloid, 2-dehydrodeacetylheterophylloidine, two norditerpene alkaloids, 14-demethyl-14-isobutyrylanhweidelphinine and 14-demethyl-14-acetylanhweidelphinine, the known alkaloids 14-deacetylnudicauline, methyllycaconitine, 14-deacetyl-14-isobutyrylnudicauline, 14-acetylbrowniine, browniine, delcosine, lycoctonine, 18-methoxygadesine, neoline, karakoline and the aporphine alkaloid magnoflorine. Structures of the alkaloids were established by MS, 1D and 2-D NMR techniques.

  13. 荷叶总生物碱降脂减肥作用的体内外试验%Effect of total alkaloids from lotus leaves on body mass and lipid regulation in vivo and in vitro .

    Institute of Scientific and Technical Information of China (English)

    范婷婷; 法鲁克; 方芳; 蒋益虹

    2013-01-01

    Summary Obesity and disorder of lipid metabolism , also called dyslipidemia , have been one of the most important diseases threating people health worldwide , and is closely connected with hypertension , high serum glucose and other cardiac‐cerebral vascular diseases . The high fat diet is the main pathogenic cause of obesity and dyslipidemia , how to regulate blood lipid and control body mass effectively has been hotspots on nutriology research nowadays . Agents from natural products that inhibit fat digestion and absorption are of theoretical benefit in the treatment of obesity and dyslipidemia . Among them , lotus ( Nelumbo nuci f era) leaf is a kind of natural plant material used both in food and medicine , which contains multiple useful components . In modern research , scientists found that alkaloids were one of the main bioactive ingredients in them , helping lowing the serum lipid level and controlling body mass . Thus , this study aims to investigate the effect of lotus leaf total alkaloids on the body mass and lipid regulation in in vivo and in vitro experiments , and to find a new potential food additive to prevent effectively obesity from abnormal fat accumulation . Lipid‐lowering efficacy in vivo of lotus leaf total alkaloids was determined by animal experiment . After adapting to the feeding environment for 10 days , 30 experimental rats were randomly divided into six experimental groups according to their serum‐lipid level and body mass , including general diet group ( blank group) , high fat diet with lotus leaf total alkaloid ( high , moderate , low doses) groups , positive drug control group and high fat diet group ( model group) . Except for the general diet group feeding normal diet , the other five groups were fed high fat diet for 40 d to set up the model of hyperlipidemia rats . Then , the contents of TC ( total cholesterol) , TG ( triglyceride) , LDL‐C ( low density lipoprotein‐cholesterol) , HDL‐C ( high density lipoprotein

  14. Total synthesis of discodermolide: optimization of the effective synthetic route.

    Science.gov (United States)

    de Lemos, Elsa; Porée, François-Hugues; Bourin, Arnaud; Barbion, Julien; Agouridas, Evangelos; Lannou, Marie-Isabelle; Commerçon, Alain; Betzer, Jean-François; Pancrazi, Ange; Ardisson, Janick

    2008-01-01

    An efficient and modulable total synthesis of discodermolide (DDM), a unique marine anticancer polyketide is described including related alternative synthetic approaches. Particularly notable is the repeated application of a crotyltitanation reaction to yield homoallylic (Z)-O-ene-carbamate alcohols with excellent selectivity. Advantage was taken of this reaction not only for the stereocontrolled building of the syn-anti methyl-hydroxy-methyl triads of DDM, but also for the direct construction of the terminal (Z)-diene. Of particular interest is also the installation of the C13=C14 (Z)-double bond through a highly selective dyotropic rearrangement. The preparation of the middle C8-C14 fragment in two sequential stages and its coupling to the C1-C7 moiety was a real challenge and required careful optimization. Several synthetic routes were explored to allow high and reliable yields. Due to the flexibility and robust character of this approach, it might enable a systematic structural variation of DDM and, therefore, the elaboration and exploration of novel discodermolide structural analogues.

  15. First total synthesis and stereochemical revision of laxaphycin B and its extension to lyngbyacyclamide A.

    Science.gov (United States)

    Boyaud, France; Mahiout, Zahia; Lenoir, Christine; Tang, Shoubin; Wdzieczak-Bakala, Joanna; Witczak, Anne; Bonnard, Isabelle; Banaigs, Bernard; Ye, Tao; Inguimbert, Nicolas

    2013-08-01

    The first total synthesis of laxaphycin B was accomplished through stepwise automated Solid Phase Peptide Synthesis (SPPS), leading to the structural revision of its stereochemistry especially with regard to the configuration of one of the two 3-hydroxyleucines of this cyclic dodecapeptide of marine origin. The analogous Lyngbyacyclamide A was obtained by an extension of this synthesis.

  16. A Submarine Journey: The Pyrrole-Imidazole Alkaloids

    Directory of Open Access Journals (Sweden)

    Alessandra Scolaro

    2009-11-01

    Full Text Available In his most celebrated tale “The Picture of Dorian Gray”, Oscar Wilde stated that “those who go beneath the surface do so at their peril”. This sentence could be a prophetical warning for the practitioner who voluntarily challenges himself with trying to synthesize marine sponge-deriving pyrrole-imidazole alkaloids. This now nearly triple-digit membered community has been growing exponentially in the last 20 years, both in terms of new representatives and topological complexity − from simple, achiral oroidin to the breathtaking 12-ring stylissadines A and B, each possessing 16 stereocenters. While the biosynthesis and the role in the sponge economy of most of these alkaloids still lies in the realm of speculations, significant biological activities for some of them have clearly emerged. This review will account for the progress in achieving the total synthesis of the more biologically enticing members of this class of natural products.

  17. A submarine journey: the pyrrole-imidazole alkaloids.

    Science.gov (United States)

    Forte, Barbara; Malgesini, Beatrice; Piutti, Claudia; Quartieri, Francesca; Scolaro, Alessandra; Papeo, Gianluca

    2009-11-27

    In his most celebrated tale "The Picture of Dorian Gray", Oscar Wilde stated that "those who go beneath the surface do so at their peril". This sentence could be a prophetical warning for the practitioner who voluntarily challenges himself with trying to synthesize marine sponge-deriving pyrrole-imidazole alkaloids. This now nearly triple-digit membered community has been growing exponentially in the last 20 years, both in terms of new representatives and topological complexity--from simple, achiral oroidin to the breathtaking 12-ring stylissadines A and B, each possessing 16 stereocenters. While the biosynthesis and the role in the sponge economy of most of these alkaloids still lies in the realm of speculations, significant biological activities for some of them have clearly emerged. This review will account for the progress in achieving the total synthesis of the more biologically enticing members of this class of natural products.

  18. A Submarine Journey: The Pyrrole-Imidazole Alkaloids

    Science.gov (United States)

    Forte, Barbara; Malgesini, Beatrice; Piutti, Claudia; Quartieri, Francesca; Scolaro, Alessandra; Papeo, Gianluca

    2009-01-01

    In his most celebrated tale “The Picture of Dorian Gray”, Oscar Wilde stated that “those who go beneath the surface do so at their peril”. This sentence could be a prophetical warning for the practitioner who voluntarily challenges himself with trying to synthesize marine sponge-deriving pyrrole-imidazole alkaloids. This now nearly triple-digit membered community has been growing exponentially in the last 20 years, both in terms of new representatives and topological complexity – from simple, achiral oroidin to the breathtaking 12-ring stylissadines A and B, each possessing 16 stereocenters. While the biosynthesis and the role in the sponge economy of most of these alkaloids still lies in the realm of speculations, significant biological activities for some of them have clearly emerged. This review will account for the progress in achieving the total synthesis of the more biologically enticing members of this class of natural products. PMID:20098608

  19. Alkaloid diversity in Galanthus elwesii and Galanthus nivalis.

    Science.gov (United States)

    Berkov, Strahil; Bastida, Jaume; Sidjimova, Borjana; Viladomat, Francesc; Codina, Carles

    2011-01-01

    Seventy alkaloids of galanthamine, lycorine, homolycorine, tazettine, haemanthamine, narciclasine, and tyramine types were detected by GC/MS in 25 Galanthus elwesii and seven Galanthus nivalis populations, collected from different locations in Bulgaria. Intraspecies diversity in the alkaloid profiles regarding the main alkaloid types (chemotypes) was observed. Tyramine-type protoalkaloids (namely, hordenine and its derivatives) were dominant in 19 populations of G. elwesii. In other populations of G. elwesii, the plants accumulated mainly homolycorine-, lycorine-, and galanthamine-type alkaloids. The alkaloid profiles of G. nivalis were dominated by narciclasine-, galanthamine-, lycorine-, haemanthamine-, or tazettine-type compounds. Geographical distribution of chemotypes indicated a relationship between populations, since adjacent populations often displayed similar alkaloid profiles. The results from year-to-year sampling and transplantation experiments imply genetic determination of alkaloid synthesis in the two studied species of Galanthus.

  20. Substrate-Controlled Asymmetric Total Synthesis and Structure Revision of (-)-Bisezakyne A.

    Science.gov (United States)

    Shin, Iljin; Lee, Dongjoo; Kim, Hyoungsu

    2016-09-01

    The first asymmetric total synthesis and subsequent structure revision of (-)-bisezakyne A, a Laurencia C15 acetogenin from Alpysia oculifera, has been accomplished. Our substrate-controlled synthesis of this oxolane natural product features a highly stereoselective "protecting-group-dependent" intramolecular amide enolate alkylation strategy for the synthesis of the key 9,10-trans-9,12-cis-10-hydroxytetrahydrofuran intermediate through "nonchelate" control. In addition, our synthesis determined the absolute configuration of the halogenated marine natural product. PMID:27551943

  1. Enantiospecific Total Synthesis of the Important Biogenetic Intermediates Along the Ajmaline Pathway, (+)-Polyneuridine and (+)-Polyneuridine Aldehyde, as well as 16-Epi-Vellosimine and Macusine A

    Science.gov (United States)

    Yin, Wenyuan; Kabir, M. Shahjahan; Wang, Zhijian; Rallapalli, Sundari K.; Ma, Jun; Cook, James M.

    2011-01-01

    The first stereospecific synthesis of polyneuridine aldehyde (6), 16-epi-vellosimine (7), (+)-polyneuridine (8), and (+)-macusine A (9) has been accomplished from commercially available D-(+)-tryptophan methyl ester. D-(+)-Tryptophan has served here both as the chiral auxiliary and the starting material for the synthesis of the common intermediate, (+)-vellosimine (13). This alkaloid was available in enantiospecific fashion in seven reaction vessels in 27% overall yield from D-(+)-trytophan methyl ester (14) via a combination of the asymmetric Pictet-Spengler reaction, Dieckmann cyclization, and a stereocontrolled intramolecular enolate-driven palladium-mediated cross-coupling reaction. A new process for this stereocontrolled intramolecular cross-coupling has been developed via a copper-mediated process. The initial results of this investigation indicated that an enolate driven palladium-mediated cross-coupling reaction can be accomplished by a copper-mediated process which is less expensive and much easier to work-up. An enantiospecific total synthesis of (+)-polyneuridine aldehyde (6), which has been proposed as an important biogenetic intermediate in the biosynthesis of quebrachidine (2), was then accomplished in an overall yield of 14.1% in 13 reaction vessels from D-(+)-tryptophan methyl ester (14). Aldehyde 13 was protected as the Na-Boc aldehyde 32 and then converted into the prochiral C (16)-quaternary diol 12 via the practical Tollens’ reaction and deprotection. The DDQ-mediated oxidative cyclization and TFA/Et3SiH reductive cleavage served as protection/deprotection steps to provide a versatile entry into the three alkaloids, polyneuridine aldehyde (6), polyneuridine (8) and macusine A (9) from the quarternary diol 12. The oxidation of the 16-hydroxymethyl group present in the axial position was achieved with the Corey-Kim reagent to provide the desired β-axial aldehydes, polyneuridine aldehyde (6) and 16-epi-vellosimine (7) with 100

  2. Enantiospecific total synthesis of the important biogenetic intermediates along the ajmaline pathway, (+)-polyneuridine and (+)-polyneuridine aldehyde, as well as 16-epivellosimine and macusine A.

    Science.gov (United States)

    Yin, Wenyuan; Kabir, M Shahjahan; Wang, Zhijian; Rallapalli, Sundari K; Ma, Jun; Cook, James M

    2010-05-21

    The first stereospecific synthesis of polyneuridine aldehyde (6), 16-epivellosimine (7), (+)-polyneuridine (8), and (+)-macusine A (9) has been accomplished from commercially available d-(+)-tryptophan methyl ester. d-(+)-Tryptophan has served here both as the chiral auxiliary and the starting material for the synthesis of the common intermediate, (+)-vellosimine (13). This alkaloid was available in enantiospecific fashion in seven reaction vessels in 27% overall yield from d-(+)-trytophan methyl ester (14) via a combination of the asymmetric Pictet-Spengler reaction, Dieckmann cyclization, and a stereocontrolled intramolecular enolate-driven palladium-mediated cross-coupling reaction. A new process for this stereocontrolled intramolecular cross-coupling has been developed via a copper-mediated process. The initial results of this investigation indicated that an enolate-driven palladium-mediated cross-coupling reaction can be accomplished by a copper-mediated process which is less expensive and much easier to work up. An enantiospecific total synthesis of (+)-polyneuridine aldehyde (6), which has been proposed as an important biogenetic intermediate in the biosynthesis of quebrachidine (2), was then accomplished in an overall yield of 14.1% in 13 reaction vessels from d-(+)-tryptophan methyl ester (14). Aldehyde 13 was protected as the N(a)-Boc aldehyde 32 and then converted into the prochiral C(16)-quaternary diol 12 via the practical Tollens' reaction and deprotection. The DDQ-mediated oxidative cyclization and TFA/Et(3)SiH reductive cleavage served as protection/deprotection steps to provide a versatile entry into the three alkaloids polyneuridine aldehyde (6), polyneuridine (8), and macusine A (9) from the quarternary diol 12. The oxidation of the 16-hydroxymethyl group present in the axial position was achieved with the Corey-Kim reagent to provide the desired beta-axial aldehydes, polyneuridine aldehyde (6), and 16-epivellosimine (7) with 100

  3. Alkaloids in the pharmaceutical industry: Structure, isolation and application

    Directory of Open Access Journals (Sweden)

    Nikolić Milan

    2003-01-01

    Full Text Available By the end of the 18th and the beginning of the 19th century a new era began in medicine, pharmaceutics and chemistry that was strongly connected with alkaloids and alkaloid drugs. Even before that it was known that certain drugs administered in limited doses were medicines, and toxic if taken in larger doses (opium, coke leaves, belladonna roots, monkshood tubers crocus or hemlock seeds. However, the identification, isolation and structural characterization of the active ingredients of the alkaloid drugs was only possible in the mid 20th century by the use of modern extraction equipment and instrumental methods (NMR, X-ray diffraction and others.In spite of continuing use over a long time, there is still great interest in investigating new drugs, potential raw materials for the pharmaceutical industry, as well as the more detailed investigation and definition of bio-active components and the indication of their activity range, and the partial synthesis of new alkaloid molecules based on natural alkaloids. The scope of these investigations, especially in the field of semi-synthesis is to make better use of the bio-active ingredients of alkaloid drugs, i.e. to improve the pharmacological effect (stronger and prolonged effect of the medicine, decreased toxicity and side effects, or to extend or change the applications. A combined classification of alkaloids was used, based on the chemical structure and origin, i.e. the source of their isolation to study alkaloid structure. For practical reasons, the following classification of alkaloids was used: ergot alkaloids, poppy alkaloids, tropanic alkaloids purine derivative alkaloids, carbon-cyclic alkaloids, and other alkaloids. The second part of this report presents a table of general procedures for alkaloid isolation from plant drugs (extraction by water non-miscible solvents, extraction by water-miscible solvents and extraction by diluted acid solutions. Also, methods for obtaining chelidonine and

  4. The CP molecule labyrinth: a paradigm of how endeavors in total synthesis lead to discoveries and inventions in organic synthesis.

    Science.gov (United States)

    Nicolaou, K C; Baran, Phil S

    2002-08-01

    Imagine an artist carving a sculpture from a marble slab and finding gold nuggets in the process. This thought is not a far-fetched description of the work of a synthetic chemist pursuing the total synthesis of a natural product. At the end of the day, he or she will be judged by the artistry of the final work and the weight of the gold discovered in the process. However, as colorful as this description of total synthesis may be, it does not entirely capture the essence of the endeavor, for there is much more to be told, especially with regard to the contrast of frustrating failures and exhilarating moments of discovery. To fully appreciate the often Herculean nature of the task and the rewards that accompany it, one must sense the details of the enterprise behind the scenes. A more vivid description of total synthesis as a struggle against a tough opponent is perhaps appropriate to dramatize these elements of the experience. In this article we describe one such endeavor of total synthesis which, in addition to reaching the target molecule, resulted in a wealth of new synthetic strategies and technologies for chemical synthesis. The total synthesis of the CP molecules is compared to Theseus' most celebrated athlos (Greek for exploit, accomplishment): the conquest of the dreaded Minotaur, which he accomplished through brilliance, skill, and bravery having traversed the famous labyrinth with the help of Ariadne. This story from Greek mythology comes alive in modern synthetic expeditions toward natural products as exemplified by the total synthesis of the CP molecules which serve as a paradigm for modern total synthesis endeavors, where the objectives are discovery and invention in the broader sense of organic synthesis. PMID:12203464

  5. Total synthesis and evaluation of [18F]MHMZ

    DEFF Research Database (Denmark)

    Herth, Matthias M; Debus, Fabian; Piel, Markus;

    2008-01-01

    Radiochemical labeling of MDL 105725 using the secondary labeling precursor 2-[(18)F]fluoroethyltosylate ([(18)F]FETos) was carried out in yields of approximately 90% synthesizing [(18)F]MHMZ in a specific activity of approximately 50MBq/nmol with a starting activity of approximately 3GBq. Overall...... radiochemical yield including [(18)F]FETos synthon synthesis, [(18)F]fluoroalkylation and preparing the injectable [(18)F]MHMZ solution was 42% within a synthesis time of approximately 100 min. The novel compound showed excellent specific binding to the 5-HT(2A) receptor (K(i)=9.0 nM) in vitro and promising in...

  6. 荷叶总生物碱脂质体的制备及质量评价%Preparing the Liposomes of Total Alkaloids of Lotus Leaf and Carrying on the Quality Appraisal

    Institute of Scientific and Technical Information of China (English)

    赵骏; 陈弼谦

    2009-01-01

    Objective :To prepare the Liposomes of tots], alkaloids of lotus leaf, and carry on the quality appraisal. Meth-ods:Reverse phase evaporation was adopted to prepare the Leptosomes of total alkaloids of lotus leaf, the Lipesomes was separated by the cation exchange resin,and the absorbance was measured at 164nm,and the encapsulation efficiency was calculated, the impact of oil - water radio, Lecithin and the addition of drug towards encapsulation efficiency was inspec-ted. Results :The experiment indicats ,while the oil-water radio is 4:1 ,the quantity of soybean lecithin is 250mg, Liposomes is roughly spherical or elliptic, and the encapsulation efficiency is 84. 9%. Conclusion:The encapsulation efficiency of Pre-paring the Liposomes of total alkaloids of lotus leaf by this method is higher.%目的:制备荷叶总生物碱脂质体,并进行质量评价.方法:采用逆相蒸发法制备荷叶总生物碱,以阳离子交换树脂法分离脂质体,于164nm处测定吸光度,计算包封率;考察油水比、卵磷脂及药物的加入量对包封率的影响.结果:实验表明,油水比为4:1,卵磷脂量为250mg时,所得脂质体呈球型或椭圆型,包封率为84.9%.结论:本法制备荷叶总生物碱脂质体包封率较高.

  7. The Catalytic Enantioselective Total Synthesis of (+)‐Liphagal

    DEFF Research Database (Denmark)

    Day, Joshua J.; McFadden, Ryan M.; Virgil, Scott C.;

    2011-01-01

    catalysis, and an intramolecular aryne capture cyclization reaction. Pivotal to the successful completion of the synthesis was a sequence involving ring expansion from a [6-5-4] tricycle to a [6-7] bicyclic core followed by stereoselective hydrogenation of a sterically occluded tri-substituted olefin...

  8. The total chemical synthesis of polymer/graphene nanocomposite films.

    Science.gov (United States)

    Salvatierra, Rodrigo V; Cava, Carlos E; Roman, Lucimara S; Oliveira, Marcela M; Zarbin, Aldo J G

    2016-01-28

    A versatile and room temperature synthesis of thin films of polymer/graphene is reported. Drastically differing from other methods, not only the polymer but also the graphene are completely built from their simplest monomers (thiophene and benzene) in a one-pot polymerization reaction at a liquid-liquid interface. The materials were characterized and electronic properties are presented. PMID:26658554

  9. 荷叶总生物碱降脂减肥作用的体内外试验%Effect of total alkaloids from lotus leaves on body mass and lipid regulation in vivo and in vitro .

    Institute of Scientific and Technical Information of China (English)

    范婷婷; 法鲁克; 方芳; 蒋益虹

    2013-01-01

    components . In modern research , scientists found that alkaloids were one of the main bioactive ingredients in them , helping lowing the serum lipid level and controlling body mass . Thus , this study aims to investigate the effect of lotus leaf total alkaloids on the body mass and lipid regulation in in vivo and in vitro experiments , and to find a new potential food additive to prevent effectively obesity from abnormal fat accumulation . Lipid‐lowering efficacy in vivo of lotus leaf total alkaloids was determined by animal experiment . After adapting to the feeding environment for 10 days , 30 experimental rats were randomly divided into six experimental groups according to their serum‐lipid level and body mass , including general diet group ( blank group) , high fat diet with lotus leaf total alkaloid ( high , moderate , low doses) groups , positive drug control group and high fat diet group ( model group) . Except for the general diet group feeding normal diet , the other five groups were fed high fat diet for 40 d to set up the model of hyperlipidemia rats . Then , the contents of TC ( total cholesterol) , TG ( triglyceride) , LDL‐C ( low density lipoprotein‐cholesterol) , HDL‐C ( high density lipoprotein‐cholesterol) , the levels of AST ( aspartate aminotransferase) and ALT ( alanine aminotransferase) in serum were assayed in hyperlipidemia rats which had been fed lotus leaf total alkaloids of 20 , 40 , 80 mg/( kg·d) and positive drug of 10 mg/( kg·d) simvastatin for another 40 days , respectively . In addition , the body mass and liver mass , body length , tail length were measured . Lipid‐lowering efficacy in vitro of lotus leaf total alkaloids was determined by measuring the inhibitory activity against pancrelipase by monitoring the hydrolysis of pNP‐b , which released the yellow chromogen p‐nitrophenol , and the buffer solution was adjusted to the condition of 37 ℃ , pH=7 .4 . The results showed that , compared with high fat diet group

  10. Progress Toward the Total Synthesis of Vinigrol and Hibarimicin B

    OpenAIRE

    Milgram, Benjamin Charles

    2013-01-01

    Vinigrol is a structurally unique diterpenoid natural product featuring a tricyclo[4.4.4.0.4a,8a]tetradecene carbon skeleton containing eight contiguous stereocenters and a challenging oxygenation pattern. Vinigrol has been demonstrated to possess a wide array of biological activities including tumor necrosis factor (TNF) antagonism, antihypertensive activity, and platelet aggregation inhibitory activity. Our first-generation plan for the synthesis of vinigrol utilized a cascade reaction sequ...

  11. Total Synthesis of Nominal Cyclocinamide B and Investigation into the Identity of the Cyclocinamides

    OpenAIRE

    Curzon, Stephanie S.; Garcia, Jessica M.; Konopelski, Joseph P.

    2014-01-01

    The total synthesis of nominal cyclocinamide B, a cyclic peptide marine natural product, is reported together with an isomer of nominal cyclocinamide A. Initial attempts at the synthesis of the title compounds by inclusion of a turn inducer failed. However, direct synthesis succeeded in formation of the 14-membered cyclic peptide structure. Comparison of the data from all synthetic cyclocinamide A and B compounds with those of the natural products leads to the conclusion that the two natural ...

  12. Enantioselective total synthesis of (+)-Lingzhiol via tandem semipinacol rearrangement/Friedel-Crafts type cyclization.

    Science.gov (United States)

    Chen, Dong; Xu, Wen-Dan; Liu, Hao-Miao; Li, Ming-Ming; Yan, Yong-Min; Li, Xiao-Nian; Li, Yan; Cheng, Yong-Xian; Qin, Hong-Bo

    2016-06-30

    Enantioselective total synthesis of (+)-Lingzhiol has been achieved. It is the first example of in tandem semipinacol rearrangement reactions, the migrated aryl group further reacting with the carbonyl oxonium electrophile to furnish a polycyclic skeleton. Our synthesis involves 13 steps and proceeds in 6% overall yield. PMID:27321202

  13. Total synthesis and allelopathic activity of cytosporones A-C

    Energy Technology Data Exchange (ETDEWEB)

    Zamberlam, Charles E.M.; Meza, Alisson; Lima, Denis P. de; Beatriz, Adilson [Centro de Ciencias Exatas e Tecnologia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS (Brazil); Leite, Carla Braga; Marques, Maria Rita [Centro de Ciencias Biologicas e da Saude, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS (Brazil)

    2012-07-01

    The search for efficient, environmentally friendly herbicides has been the focus of numerous studies on the organic synthesis of compounds isolated from natural sources. Cytosporones, which are phenolic lipids isolated from fungi, exhibit noteworthy biological properties. This paper reports the preparation of cytosporones A-C from the same starting material through a short synthetic route, with good yields. All compounds were tested for allelopathic activity on lettuce (Lactuca sativa L) seeds. Cytosporone A and its methylated precursor showed remarkable allelopathic activity, inhibiting seed germination and plantule growth. (author)

  14. One-pot multiple reactions: asymmetric synthesis of 2,6-cis-disubstituted piperidine alkaloids from chiral aziridine.

    Science.gov (United States)

    Yadav, Nagendra Nath; Choi, Jihye; Ha, Hyun-Joon

    2016-07-01

    A divergent, new, and highly stereoselective synthesis of cis-2,6-disubstituted piperidine natural products including isosolenopsins, deoxocassine, and spectaline was achieved from chiral aziridine decorated with appropriate alkyl chains for isosolenopsins or alkynyl groups for deoxocassine and spectaline at C2. The characteristic feature of this synthesis is one-pot sequential reactions under atmospheric hydrogen including the reduction of alkyne (for deoxocassine and spectaline), reductive ring-opening of aziridine, debenzylation, and intramolecular reductive amination in high yields. The prerequisite aziridines were elaborated from commercially available (2S)-hydroxymethylaziridine through oxidation, Wittig olefination, and the Grignard reaction for isosolenopsins or substrate-controlled lithium alkynylate addition for deoxocassine and spectaline. PMID:27189444

  15. Remarkable Stereoelectronic Effect of the Methylenedioxy Phenyl System in the Total Synthesis of Cephalotaxine

    Institute of Scientific and Technical Information of China (English)

    Hua YANG; Yong Qiang WANG; Wei DongZ. LI

    2005-01-01

    Methylenedioxyphenyl unit displays a significant stereoelectronic effect in some key transformations in the total synthesis of cephalotaxine. The ring-strain of methylenedioxy ring may account for some important facile ring-skeleton rearrangements.

  16. Harnessing Quinone Methides: Total Synthesis of (±)‐Vaticanol A

    DEFF Research Database (Denmark)

    Jepsen, Tue Heesgaard; Thomas, Stephen; Yunqing, lin;

    2014-01-01

    Although quinone methides are often postulated as intermediates in the biosynthesis of many polyphenolic natural products, deploying their power in a laboratory setting to achieve similar bond constructions has sometimes proven challenging. Herein, a total synthesis of the resveratrol trimer...

  17. A carbohydrate approach for the formal total synthesis of (−-aspergillide C

    Directory of Open Access Journals (Sweden)

    Pabbaraja Srihari

    2014-12-01

    Full Text Available An enantioselective formal total synthesis of aspergillide C is accomplished using commercially available tri-O-acetyl-D-galactal employing a Ferrier-type C-glycosylation, utilizing a Trost hydrosilylation and protodesilylation as key reactions.

  18. Total Synthesis of Sporolide B and 9-epi-Sporolide B

    OpenAIRE

    Nicolaou, K. C.; Wang, Jianhua; Tang, Yefeng; Botta, Lorenzo

    2010-01-01

    The total synthesis of the structurally unique secondary metabolite sporolide B (1b, Figure 1) is described. The total synthesis of 1b was developed on the basis of preliminary studies that revealed the reactivity of an appropriate o-quinone as a diene system toward a number of indene derivatives as dienophiles, first in intermolecular and thence intramolecular settings. Thus, substrates were devised (37, Scheme 5; 75, Scheme 11) that underwent exquisite intramolecular [4+2] cycloaddition rea...

  19. Solid substrate mediated changes in ergot alkaloid spectra in solid state fermentation system

    OpenAIRE

    Trejo Hernandez, M.R.; Lonsane, B.K.; Raimbault, Maurice; Roussos, Sevastianos

    1993-01-01

    Use of different solid substrates resulted in minor alterations in total alkaloid production by #Claviceps purpurea$ 1029c in solid state fermentation system but the changes in the spectra of ergot alkaloids were of significantly higher magnitudes. Ergonovine accounted for 93% of the total alkaloid production in wheat grain medium while lysergic acid derivatives and ergonovine comprised of 66% and 32% of total alkaloids in rye grain medium. In contrast, ergonovine, ergotamine, and lysergic ac...

  20. Determination of total alkaloids in Croton tiglium by acid dye colorimetry%酸性染料比色法测定巴豆中总生物碱的含量

    Institute of Scientific and Technical Information of China (English)

    曾宝; 李生梅; 古俊辉; 唐君苹; 林吉; 赖小平

    2012-01-01

    目的 建立巴豆中总生物碱含量的测定方法,对不同产地的巴豆总生物碱质量分数进行比较研究.方法 以木兰花碱作为对照品,采用酸性染料比色法测定巴豆中总生物碱质量分数.结果酸性染料法的显色条件为加pH 6.0缓冲液至8 mL,加溴麝香草酚蓝3.5 mL,振摇3min,静置40 min,三氯甲烷8mL萃取,测定波长为420 nm,在0.024 6~0.147 3 mg范围内线性关系良好(r=0.999 5),平均回收率99.0%,RSD为2.75%.结论 本含量测定方法操作简单,灵敏度高,准确性、重复性好,可用于巴豆中总生物碱的含量测定.%Objective To establish a method for the assay of the total alkaloids in Croton tiglium, and investigate the contents from different origins. Methods Acidic dye colorimetry was used for the determination of total alkaloids in Croton tiglium with magnoflorine as reference substance. Results Acid dye colorimetric conditions were as follows; pH6.0 buffer to 8.0 mL, adding 3. 5 mL bromothymol blue, extracting with 8 mL chloroform, shaking out for 3 minutes, stewing for at least 40 min, then determining at the wavelength of 420 nm. The concentration of magnoflorine showed good linearity within the range of 0. 024 6-0. 147 3 mg, r = 0. 999 5, and the average recovery ratio was 99. 0% with RSD of 2. 75%. Conclusion This method is simple, highly sensitive, accurate and reproducible, which can be used for determination of the total alkaloids in Croton tiglium.

  1. Alkaloids in Marine Algae

    OpenAIRE

    Ekrem Sezik; Aline Percot; Kasım Cemal Güven

    2010-01-01

    This paper presents the alkaloids found in green, brown and red marine algae. Algal chemistry has interested many researchers in order to develop new drugs, as algae include compounds with functional groups which are characteristic from this particular source. Among these compounds, alkaloids present special interest because of their pharmacological activities. Alkaloid chemistry has been widely studied in terrestrial plants, but the number of studies in algae is insignificant. In this review...

  2. Total synthesis of amiclenomycin, an inhibitor of biotin biosynthesis.

    Science.gov (United States)

    Mann, Stéphane; Carillon, Sophie; Breyne, Olivier; Marquet, Andrée

    2002-01-18

    We describe the first synthesis of amiclenomycin, a natural product that has been found to inhibit biotin biosynthesis and, as a consequence, to exhibit antibiotic properties. Structure 1, with a trans relationship between the ring substituents. had previously been proposed for amiclenomycin on the basis of its 1H NMR spectrum. We have prepared the trans and cis isomers 1 and 2 by unequivocal routes and we conclude that the natural product is in fact the cis isomer 2. The properly substituted cyclohexadienyl rings were constructed first. A cycloaddition reaction between 1,2-di(phenylsulfonyl)ethylene and the N-allyloxycarbonyl diene 13, followed by reductive elimination of the phenylsulfinyl groups, gave the cis isomer 15. To obtain the trans isomer, the O-trimethylsilyl diene was used to give the cis hydroxylated Diels-Alder adduct 33, which was transformed into the corresponding trans amino derivative by means of a Mitsunobu reaction. The L-alpha-amino acid functionality was introduced by means of a Strecker reaction on the aldehydes 16 and 42, followed by enzymatic hydrolysis with immobilised pronase. PMID:11843156

  3. Visual identification of alkaloids in some medicinal plants: common alkaloid reagents versus bromocresol green

    Directory of Open Access Journals (Sweden)

    Shamsa F, Esfahani HR, Gamooshi RA

    2008-07-01

    Full Text Available "n Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Background: Alkaloids are a group of nitrogenous compounds with potential effects on the physiological behavior of human and animals. Some of these compounds are considered important drugs in modern medicine, such as atropine and morphine. Plants are considered the most important source of alkaloids. Therefore, investigating the presence of alkaloids in different plants is very important. Usually, alkaloids in plants are identified by methods such as those of Dragendorf, Wagner and Meyer, among others, which require milligrams of alkaloids for identification. In the present study, a fast and sensitive procedure for detecting of alkaloids in plants is presented.   "n"nMethods: Twelve dried plants samples were investigated for the presence alkaloids. After extracting the total alkaloid into methanol using a Soxhlet extractor, a few milligrams of the extract was transferred to a separatory funnel, buffered to pH 4.7, the bromocresol green (BCG solution (10-4 M was added, mixed and extracted with CHCl3 until a yellow color was observed in the CHCl3 layer, indicating the presence of the alkaloid. The crude extracts were also investigated by the standard methods of Dragendorf, Wagner and Meyer for the presence of alkaloids.   "n"nResults: Investigation of the 12 plant samples for the presence of alkaloids by the standard reagents of Dragendorf, Wagner, and Meyer showed that only Camelia sinensis (flowers, Echium amoenum Fisch & Mey (flowers, and Stachys (aerial parts are devoid

  4. The Total Synthesis Problem of linear multivariable control. II - Unity feedback and the design morphism

    Science.gov (United States)

    Sain, M. K.; Antsaklis, P. J.; Gejji, R. R.; Wyman, B. F.; Peczkowski, J. L.

    1981-01-01

    Zames (1981) has observed that there is, in general, no 'separation principle' to guarantee optimality of a division between control law design and filtering of plant uncertainty. Peczkowski and Sain (1978) have solved a model matching problem using transfer functions. Taking into consideration this investigation, Peczkowski et al. (1979) proposed the Total Synthesis Problem (TSP), wherein both the command/output-response and command/control-response are to be synthesized, subject to the plant constraint. The TSP concept can be subdivided into a Nominal Design Problem (NDP), which is not dependent upon specific controller structures, and a Feedback Synthesis Problem (FSP), which is. Gejji (1980) found that NDP was characterized in terms of the plant structural matrices and a single, 'good' transfer function matrix. Sain et al. (1981) have extended this NDP work. The present investigation is concerned with a study of FSP for the unity feedback case. NDP, together with feedback synthesis, is understood as a Total Synthesis Problem.

  5. Total synthesis of microcin B17 via a fragment condensation approach.

    Science.gov (United States)

    Thompson, Robert E; Jolliffe, Katrina A; Payne, Richard J

    2011-02-18

    The total synthesis of the 43 amino acid antibacterial peptide Microcin B17 (MccB17) is described. The natural product was synthesized via a convergent approach from a heterocycle-derived peptide and peptide thioester fragments prepared via Fmoc-strategy solid phase peptide synthesis (SPPS). Final assembly was achieved in an efficient manner using two Ag(I)-assisted peptide ligation reactions to afford MccB17 in excellent overall yield.

  6. Total synthesis of furospongolide and related furanolipid analogues as potential anti-tumour agents

    OpenAIRE

    Harrold, Donal Patrick

    2014-01-01

    This thesis details the design, development and execution of innovative methodology in the total synthesis of the terpene-derived marine natural product, furospongolide. It also outlines the synthetic routes used to prepare a novel range of furanolipids derivatives and subsequent evaluation of their potential as antitumour agents. The first chapter is a review of the literature describing efforts undertaken towards the synthesis of biologically active furanosesterterpenoid marine natural prod...

  7. Total synthesis of (3S, 5R, 3'S, 5'R)-capsorubin

    Energy Technology Data Exchange (ETDEWEB)

    Frederico, Daniel; Constantino, Mauricio G.; Donate, Paulo M. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Quimica

    2009-07-01

    The total synthesis of enantiomerically enriched (3S, 5R, 3'S, 5'R)-capsorubin (1) by aldol condensation of (1R, 4S)-1-(4-hydroxy-1,2,2-trimethyl-cyclopentyl)ethanone (2a) and crocetindial (3) is described. An alternative, short eight-step synthesis of the optically active compound 2a (ee 89%) is also reported. (author)

  8. Stereoselective total synthesis of the potent anti-asthmatic compound CMI-977 (LDP-977)

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Luiz Carlos; Farina, Lui Strambi; Ferreira, Marco Antonio Barbosa, E-mail: ldias@iqm.unicamp.br [Universidade de Campinas (UNICAMP), SP (Brazil). Instituto de Quimica

    2013-02-15

    A short and efficient stereoselective total synthesis of CMI-977 (LDP-977), a potent and orally active anti-asthmatic compound, was developed. The key steps involve a highly diastereoselective Mukaiyama oxidative cyclization, which provides the trans-THF (tetrahydrofuran) unit and a Seyferth-Gilbert homologation to construct the triple bond in the target molecule. The synthesis of the key chiral building block was performed using Jacobsen hydrolytic kinetic resolution. (author)

  9. Total Synthesis of Ionic Liquid Systems for Dissolution of Lunar Simulant

    Science.gov (United States)

    Sharpe, Robert J.; Karr, Laurel J.; Paley, Mark S.

    2010-01-01

    For purposes of Space Resource Utilization, work in the total synthesis of a new ionic liquid system for the extraction of oxygen and metals from lunar soil is studied and described. Reactions were carried out according to procedures found in the chemical literature, analyzed via Thin-Layer Chromatography and 1H Nuclear Magnetic Resonance Spectroscopy and purified via vacuum distillation and rotary evaporation. Upon final analysis via 1H NMR, it was found that while the intermediates of the synthesis had been achieved, unexpected side products were also present. The mechanisms and constraints of the synthesis are described as well as the final results of the project and recommendations for continued study

  10. Total Synthesis of (+)-Cytosporolide A via a Biomimetic Hetero-Diels-Alder Reaction.

    Science.gov (United States)

    Takao, Ken-Ichi; Noguchi, Shuji; Sakamoto, Shu; Kimura, Mizuki; Yoshida, Keisuke; Tadano, Kin-Ichi

    2015-12-23

    The first total synthesis of (+)-cytosporolide A was achieved by a biomimetic hetero-Diels-Alder reaction of (-)-fuscoatrol A with o-quinone methide generated from (+)-CJ-12,373. The dienophile, highly oxygenated caryophyllene sesquiterpenoid (-)-fuscoatrol A, was synthesized from the synthetic intermediate in our previous total synthesis of (+)-pestalotiopsin A. The o-quinone methide precursor, isochroman carboxylic acid (+)-CJ-12,373, was synthesized through a Kolbe-Schmitt reaction and an oxa-Pictet-Spengler reaction. The hetero-Diels-Alder reaction of these two compounds proceeded with complete chemo-, regio-, and stereoselectivity to produce the complicated pentacyclic ring system of the cytosporolide skeleton. This total synthesis unambiguously demonstrates that natural cytosporolide A has the structure previously suggested. PMID:26633257

  11. Streamlined Total Synthesis of Uncialamycin and Its Application to the Synthesis of Designed Analogues for Biological Investigations.

    Science.gov (United States)

    Nicolaou, K C; Wang, Yanping; Lu, Min; Mandal, Debashis; Pattanayak, Manas R; Yu, Ruocheng; Shah, Akshay A; Chen, Jason S; Zhang, Hongjun; Crawford, James J; Pasunoori, Laxman; Poudel, Yam B; Chowdari, Naidu S; Pan, Chin; Nazeer, Ayesha; Gangwar, Sanjeev; Vite, Gregory; Pitsinos, Emmanuel N

    2016-07-01

    From the enediyne class of antitumor antibiotics, uncialamycin is among the rarest and most potent, yet one of the structurally simpler, making it attractive for chemical synthesis and potential applications in biology and medicine. In this article we describe a streamlined and practical enantioselective total synthesis of uncialamycin that is amenable to the synthesis of novel analogues and renders the natural product readily available for biological and drug development studies. Starting from hydroxy- or methoxyisatin, the synthesis features a Noyori enantioselective reduction, a Yamaguchi acetylide-pyridinium coupling, a stereoselective acetylide-aldehyde cyclization, and a newly developed annulation reaction that allows efficient coupling of a cyanophthalide and a p-methoxy semiquinone aminal to forge the anthraquinone moiety of the molecule. Overall, the developed streamlined synthesis proceeds in 22 linear steps (14 chromatographic separations) and 11% overall yield. The developed synthetic strategies and technologies were applied to the synthesis of a series of designed uncialamycin analogues equipped with suitable functional groups for conjugation to antibodies and other delivery systems. Biological evaluation of a select number of these analogues led to the identification of compounds with low picomolar potencies against certain cancer cell lines. These compounds and others like them may serve as powerful payloads for the development of antibody drug conjugates (ADCs) intended for personalized targeted cancer therapy. PMID:27266267

  12. [Alkaloids of Annonaceae. XXIX. Alkaloids of Annona muricata].

    Science.gov (United States)

    Leboeuf, M; Legueut, C; Cavé, A; Desconclois, J F; Forgacs, P; Jacquemin, H

    1981-05-01

    From leaves, root - and stem - barks of Annona muricata L., seven isoquinoline alkaloids have been isolated: reticuline (main alkaloid), coclaurine, coreximine, atherosperminine, stepharine. Anomurine and anomuricine, two minor alkaloids, are new tetrahydrobenzylisoquinolines, with 5, 6, 7 substituted ring A. The phytochemical significance of these alkaloids is discussed.

  13. Enantioselective Total Synthesis of (+)-Steenkrotin A and Determination of Its Absolute Configuration.

    Science.gov (United States)

    Pan, Saiyong; Gao, Beiling; Hu, Jialei; Xuan, Jun; Xie, Hujun; Ding, Hanfeng

    2016-01-18

    The first enantioselective total synthesis of (+)-steenkrotin A has been achieved in 18 steps and 4.2 % overall yield. The key features of the strategy entail a Rh-catalyzed O-H bond insertion followed by an intramolecular carbonyl-ene reaction, two sequential SmI2 -mediated Ueno-Stork and ketyl-olefin cyclizations, and a cascade intramolecular aldol condensation/vinylogous retro-aldol/aldol process with inversion of the relative configuration at the C7 position. The absolute configuration of (+)-steenkrotin A was determined based on the stepwise construction of the stereocenters during the total synthesis. PMID:26660855

  14. Chemistry of Renieramycins. Part 14: Total Synthesis of Renieramycin I and Practical Synthesis of Cribrostatin 4 (Renieramycin H

    Directory of Open Access Journals (Sweden)

    Masashi Yokoya

    2015-08-01

    Full Text Available The first total synthesis of (±-renieramycin I, which was isolated from the Indian bright blue sponge Haliclona cribricutis, is described. The key step is the selenium oxide oxidation of pentacyclic bis-p-quinone derivative (3 stereo- and regioselectively. We also report a large-scale synthesis of cribrostatin 4 (renieramycin H via the C3-C4 double bond formation in an early stage based on the Avendaño’s protocol, from readily available 1-acetyl-3-(3-methyl-2,4,5-trimethylphenylmethyl-piperazine-2,5-dione (8 in 18 steps (8.3% overall yield. The synthesis provides unambiguous evidence supporting the original structure of renieramycin I.

  15. Cinchona alkaloid squaramide catalyzed enantioselective hydrazination/cyclization cascade reaction of α-isocyanoacetates and azodicarboxylates: synthesis of optically active 1,2,4-triazolines.

    Science.gov (United States)

    Zhao, Mei-Xin; Bi, Hong-Lei; Zhou, Hao; Yang, Hui; Shi, Min

    2013-09-20

    An efficient enantioselective hydrazination/cyclization cascade reaction of α-substituted isocyanoacetates to azodicarboxylates catalyzed by Cinchona alkaloid derived squaramide catalysts has been investigated, affording the optically active 1,2,4-triazolines in excellent yields (up to 99%) and good to excellent enantioselectivities (up to 97% ee) under mild conditions. PMID:23984761

  16. Formal Total Synthesis of Diazonamide A by Indole Oxidative Rearrangement.

    Science.gov (United States)

    David, Nadège; Pasceri, Raffaele; Kitson, Russell R A; Pradal, Alexandre; Moody, Christopher J

    2016-07-25

    A short formal total synthesis of the marine natural product diazonamide A is described. The route is based on indole oxidative rearrangement, and a number of options were investigated involving migration of tyrosine or oxazole fragments upon oxidation of open chain or macrocyclic precursors. The final route proceeds from 7-bromoindole by sequential palladium-catalysed couplings of an oxazole fragment at C-2, followed by a tyrosine fragment at C-3. With the key 2,3-disubstituted indole readily in hand, formation of a macrocyclic lactam set the stage for the crucial oxidative rearrangement to a 3,3-disubstituted oxindole. Notwithstanding the concomitant formation of the unwanted indoxyl isomer, the synthesis successfully delivered, after deprotection, the key oxindole intermediate, thereby completing a formal total synthesis of diazonamide A. PMID:27346186

  17. Steroidal glyco alkaloids and molluscicidal activity of Solanum asperum Rich. fruits

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Tania M.S. [Instituto Multidisciplinar em Saude, Vitoria da Conquista, BA (Brazil). Campus Avancado Anisio Teixeira]. E-mail: sarmento@pesquisador.cnpq.br; Camara, Celso A. [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Dept. de Quimica; Freire, Kristerson R.L.; Silva, Thiago G. da; Agra, Maria de F.; Bhattacharyya, Jnanabrata [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Lab. de Tecnologia Farmaceutica

    2008-07-01

    Bioassay-guided fractionation of the alkaloidal extract of the green fruits of Solanum asperum afforded a new compound, solanandaine along with solasonine and solamargine. The total crude alkaloids as well as the isolated pure alkaloids exhibited significant molluscicidal activity. (author)

  18. Genotoxic effect of alkaloids

    Directory of Open Access Journals (Sweden)

    J. A. P. Henriques

    1991-01-01

    Full Text Available Because of the increase use of alkaloids in general medical practice in recent years, it is of interest to determine genotoxic, mutagenic and recombinogenic response to different groups of alkaloids in prokaryotic and eucaryotic organisms. Reserpine, boldine and chelerythrine did not show genotoxicity response in the SOS-Chromotest whereas skimmianine showed genotixicity in the presence of a metabolic activation mixture. Voacristine isolated fromthe leaves of Ervatamia coronaria shows in vivo cytostatic and mutagenic effects in Saccharomyces cerevisiae hapioids cells. The Rauwolfia alkaloid (reserpine was not able to induce reverse mutation and recombinational mitotic events (crossing-over and gene conversion in yeast diploid strain XS2316.

  19. Asymmetric total synthesis of (-)-jorunnamycins A and C and (-)-jorumycin from L-tyrosine.

    Science.gov (United States)

    Chen, Ruijiao; Liu, Hao; Chen, Xiaochuan

    2013-09-27

    Three renieramycin-type antitumor alkaloids, (-)-jorunnamycins A (1) and C (2) and (-)-jorumycin (3), have been synthesized by a new convergent approach, which features a highly regio- and stereoselective Pictet-Spengler cyclization to couple the isoquinoline and the trisubstituted phenylalaninol partners. This synthetic strategy opens an economical access to these important antitumor alkaloids with high yields: (-)-jorunnamycin A, as a common precursor to other renieramycin-type alkaloids and their analogues, is obtained with 18.1% overall yield from l-tyrosine. PMID:24070054

  20. Antidepressant effects of total tertiary alkaloid fraction of Cissampelos sympodialis Eichler in rodents Efeitos antidepressivos da fração de alcalóides terciários totais de Cissampelos sympodialis Eichler em roedores

    Directory of Open Access Journals (Sweden)

    Sueli Mendonça-Netto

    2008-06-01

    Full Text Available The purpose of the present study was to evaluate the effects of total tertiary alkaloid fraction (TTAF of Cissampelos sympodialis Eichler (Menispermaceae on two animal models of depression: a forced swim test and b reserpine test. Treatment of mice with TTAF (12.5 mg/kg reduced the total immobility time. It also reversed the reserpine-induced hypothermia, demonstrating an antidepressant effect in both models. Additionally, TTAF treatment did not modify the ambulation and rearing evaluated in open field test in order to investigate if the immobility time reduction found in the forced swimming test was caused by locomotive activity stimulation. Since warifteine is one of the main alkaloids present in the TTAF of C. sympodialis, and it has inhibitory activity of the phosphodiesterase enzyme, it may be responsible by the antidepressant effect found in the fraction studied.A proposta deste trabalho foi de avaliar os efeitos da fração de alcalóides terciários totais (TTAF de Cissampelos sympodialis Eichler (Menispermaceae em dois modelos animais de depressão: a teste do nado forçado e b teste da reserpina. O tratamento de camundongos com TTAF (12,5 mg/kg reduziu o tempo total de imobilidade dos animais. Também reverteu a hipotermia induzida por reserpina, demonstrando um efeito antidepressivo nos dois modelos. Adicionalmente, o tratamento com TTAF não modificou a ambulação e o comportamento de levantar das patas dianteiras dos animais avaliados no teste do campo aberto, realizado no intuito de investigar se a redução no tempo de imobilidade apresentada no teste do nado forçado foi causada por estimulação na atividade locomotora. Como a warifteína é um dos principais alcalóides presente na TTAF da C. sympodialis, e tem atividade inibidora da enzima fosfodiesterase, ela pode ser responsável pelo efeito antidepressivo observado na fração estudada.

  1. Catalytic Macrocyclization Strategies Using Continuous Flow: Formal Total Synthesis of Ivorenolide A.

    Science.gov (United States)

    de Léséleuc, Mylène; Godin, Éric; Parisien-Collette, Shawn; Lévesque, Alexandre; Collins, Shawn K

    2016-08-01

    A formal total synthesis of ivorenolide A has been accomplished employing a Z-selective olefin cross metathesis and a macrocyclic Glaser-Hay coupling as key steps. The macrocyclization protocol employed a phase separation/continuous flow manifold whose advantages include catalysis, fast reaction times, high concentrations, and facile scale-up. PMID:27404899

  2. The first total synthesis of the novel triquinane natural products pleurotellol and pleurotellic acid

    OpenAIRE

    Mehta, Goverdhan; Murthy, Sai Krishna A

    2003-01-01

    The first total synthesis of the triquinane based sesquiterpenoid antibiotics (±)-pleurotellol and (±)-pleurotellic acid isolated from the fermentation broth of Pleurotellus hypnophilus have been accomplished. The triquinane based bis-enone system obtained via photo-thermal metathesis in a caged pentacyclic dione has been elaborated to the natural products through carefully crafted functional group transformations.

  3. First total synthesis of yanuthones: novel farnesylated epoxycyclohexenoid marine natural products

    OpenAIRE

    Mehta, Goverdhan; Pan, Subhas Chandra

    2005-01-01

    The total synthesis of the recently isolated marine natural products of mixed biosynthetic origin, yanuthones A, 13 C and 22-deacylyanuthone A,has been accomplished following a short regio- and stereocontrolled approach involving the key intermediacy of 2-farnesyl-p-benzoquinone.

  4. Selective bromochlorination of a homoallylic alcohol for the total synthesis of (−)-anverene

    Science.gov (United States)

    Seidl, Frederick J

    2016-01-01

    Summary The scope of a recently reported method for the catalytic enantioselective bromochlorination of allylic alcohols is expanded to include a specific homoallylic alcohol. Critical factors for optimization of this reaction are highlighted. The utility of the product bromochloride is demonstrated by the first total synthesis of an antibacterial polyhalogenated monoterpene, (−)-anverene. PMID:27559385

  5. First Total Synthesis of an Analogue of (±)—Hypargenin B

    Institute of Scientific and Technical Information of China (English)

    AnPaiLI; HuiWANG; 等

    2002-01-01

    First total synthesis of (±)-hypargenin B methyl ether 2 was accomplished via a strategy of AC→ABC,in which CrO3/H2O/NaOAc/HOAc system was utilized for introducing 7-keto group in order to aviod dehydration of benzyl tertiary alcohol.

  6. Total Synthesis and Complete Stereostructure of a Marine Macrolide Glycoside, (-)-Lyngbyaloside B.

    Science.gov (United States)

    Fuwa, Haruhiko; Yamagata, Naoya; Okuaki, Yuta; Ogata, Yuya; Saito, Asami; Sasaki, Makoto

    2016-05-10

    We have described in detail the total synthesis of both the proposed and correct structures of (-)-lyngbyaloside B, which facilitated the elucidation of the complete stereostructure of this natural product. Our study began with the total synthesis of 13-demethyllyngbyaloside B, in which an esterification/ring-closing metathesis (RCM) strategy was successfully used for the efficient construction of the macrocycle. We also established reliable methods for the introduction of the conjugated diene side chain and the l-rhamnose residue onto the macrocyclic framework. However, the esterification/RCM strategy proved ineffective for the parent natural product because of the difficulties in acylating the sterically encumbered C-13 tertiary alcohol; macrolactionization of a seco-acid was also extensively investigated under various conditions without success. We finally completed the total synthesis of the proposed structure of (-)-lyngbyaloside B by means of a macrolactonization that involves an acyl ketene as the reactive species. However, the NMR spectroscopic data of our synthetic material did not match those of the authentic material, which indicated that the proposed structure must be re-examined. Inspection of the NMR spectroscopic data of the natural product and molecular mechanics calculations led us to postulate that the configuration of the C-10, C-11, and C-13 stereogenic centers had been incorrectly assigned in the proposed structure. Finally, our revised structure of (-)-lyngbyaloside B was unambiguously verified through total synthesis. PMID:27112323

  7. Buchner and Beyond: Arene Cyclopropanation as Applied to Natural Product Total Synthesis

    OpenAIRE

    Reisman, Sarah E.; Nani, Roger R.; Levin, Sergiy

    2011-01-01

    Buchner and Curtius first reported the cyclopropanation of arenes in 1885. Since the initial discovery, the Buchner reaction has been the subject of significant research by both physical and synthetic organic chemists. Described herein is a brief overview of the Buchner reaction and related arene cyclopropanation processes, with an emphasis on their application to natural product total synthesis.

  8. First Total Synthesis of an Analogue of (±)-Hypargenin B

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    First total synthesis of (±)-hypargenin B methyl ether 2 was accomplished via a  strategy of AC→ABC, in which CrO3/H2O/NaOAc/HOAc system was utilized for introducing  7-keto group in order to avoid dehydration of benzyl tertiary alcohol.

  9. First Total Synthesis of (±)-Abieta-8, 11, 13-trien-7β-ol

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The first total synthesis of (±)-abieta-8, 11, 13-trien-7β-ol (7) was accomplished via a strategy of AC→ABC, in which the reduction of the ketone 6 with LiAlH4 gave exclusively the title compound.

  10. Total synthesis of exiguamines A and B inspired by catecholamine chemistry.

    Science.gov (United States)

    Sofiyev, Vladimir; Lumb, Jean-Philip; Volgraf, Matthew; Trauner, Dirk

    2012-04-16

    The evolution of a total synthesis of the exiguamines, two structurally unusual natural products that are highly active inhibitors of indolamine-2,3-dioxygenase (IDO), is described. The ultimately successful strategy involves advanced cross-coupling methodology and features a potentially biosynthetic tautomerization/electrocyclization cascade reaction that forms two heterocycles and installs a quaternary ammonium ion in a single synthetic operation.

  11. A Biomimetic Strategy to Access the Silybins: Total Synthesis of (−)-Isosilybin A

    OpenAIRE

    McDonald, Benjamin R.; Nibbs, Antoinette E.; Scheidt, Karl A.

    2014-01-01

    We report the first asymmetric, total synthesis of (−)-isosilybin A. A late-stage catalytic biomimetic cyclization of a highly functionalized chalcone is employed to form the characteristic benzopyranone ring. A robust and flexible approach to this chalcone provides an entry to the preparation of the entire isomeric family of silybin natural products.

  12. Crotylsilane reagents in the synthesis of complex polyketide natural products: total synthesis of (+)-discodermolide.

    Science.gov (United States)

    Arefolov, Alexander; Panek, James S

    2005-04-20

    An efficient, highly convergent stereocontrolled synthesis of (+)-discodermolide has been achieved with 2.1% overall yield (27 steps longest linear sequence). The absolute stereochemistry of the C1-C6 (12), C7-C14 (13), and C15-C24 (11) subunits was introduced using asymmetric crotylation methodology. Key elements of the synthesis include the use of hydrozirconation-cross-coupling methodology for the construction of C13-C14 (Z)-olefin, acetate aldol reaction to construct the C6-C7 bond and install the C7 stereocenter with high levels of 1,5-anti stereoinduction, and the use of palladium-mediated sp(2)-sp(3) cross-coupling reaction to join the advanced fragments, which assembled the carbon framework of discodermolide.

  13. 苦地丁总生物碱对小鼠Ⅱ型胶原关节炎的影响%Effect of total alkaloids from Cory dalis bengeana Turcz .on collagen-induced ar-thritis in mice

    Institute of Scientific and Technical Information of China (English)

    张利; 吴凯; 葛亮; 张家明

    2014-01-01

    目的:探讨苦地丁对小鼠Ⅱ型胶原关节炎的影响。方法小鼠尾根部皮内注射Ⅱ型胶原乳剂建立小鼠关节炎模型(CIA ),苦地丁总生物碱(50,100,200 mg · kg -1组灌胃给药,每日1次;模型组和空白组灌胃给予等量蒸馏水;实验结束时考察各组临床积分、发病时间、血清中抗-CⅡ抗体含量、胶原所致耳廓DTH ;ELISA法检测PGE2、TNF-α、IL-1的水平。结果苦地丁剂量依赖性延迟CIA小鼠的发病时间,减少关节的肿胀和红斑,缓解CIA小鼠体质量减轻,降低小鼠血清中抗-CⅡ抗体水平,抑制CⅡ诱导的小鼠耳廓迟发型超敏反应;明显抑制巨噬细胞释放肿瘤坏死因子(TNF-α)、白介素1(IL-1),但对前列腺素(PGE2)的产生无明显影响。结论苦地丁对小鼠CIA有明显的抑制作用。%Objective To investigate the therapeutic effects of Corydalis bengeana Turcz .on collagen Ⅱ-induced arthritis(CIA) in mice .Methods The CIA model was established by intradermal injection of type Ⅱ collagen emulsion into mice tail .The total al-kaloids from C .bengeana (50 ,100 ,200 mg · kg -1 ) were orally administrated daily .Model group and control group mice were ad-ministrated with saline .At the end of the experiment groups ,clinical integral ,onset time ,anti-C Ⅱ antibodies in the serum , DTH ,macrophage proliferation and activities of tumor necrosis factor-alpha(TNF-α) ,interleukin-1(IL-1) ,prostaglandin E2 (PGE2 ) were respectively determined .Results The results showed that the total alkaloids dose-dependently delayed the onset time of CIA ,diminished the swelling and erythema on the joints ,relieved the loss of body weight ,decreased the titer of anti-CⅡantibody in serum ,suppressed the delayed type hypersensitivity(DTH) against CⅡ in ears .The total alkaloids also inhibited the release of TNF-α,IL-1 from macrophages ,but did not affect the production of PGE2 .Conclusion C .bengeana has

  14. 3,4-桥环吲哚类生物碱的合成研究进展%Progress in Synthesis of 3,4-Fused Indole Alkaloids

    Institute of Scientific and Technical Information of China (English)

    单冬; 贾彦兴

    2013-01-01

    取代的吲哚类天然产物是自然界中普遍存在的一类杂环化合物,由于其具有广泛的生理活性,以及相当一部分作为重要的临床使用药物,100多年以来,吲哚的合成及官能团化一直是有机合成化学家关注的一个重要领域.在众多吲哚类生物碱中,含有3,4-桥环吲哚骨架的天然产物占据了相当一部分,由于其独特的结构和良好的生物活性,这些分子引起了有机合成化学家的广泛兴趣.重点概述了构建3,4-桥环骨架的主要合成方法和策略,并对一些方法在天然产物全合成中的应用作简要介绍.%The indole nucleus is one of the most important heterocycles for its presence in a vast number of bioactive natural products,pharmaceuticals,and agrochemicals.Due to their widest spectrum of biological activity and some of them have been used in clinical trials,construction and functionalization of indoles have attracted considerable interests from synthetic and medicinal chemists for over a hundred years.Among the naturally occurring indole alkaloids,those containing 3,4-fused indole skeleton possess a major part and have been especially considered attractive synthetic targets because of their unique structure and biological activities.This review emphasized on the methodologies and strategies of construction of 3,4-fused indole skeleton,and their application in total synthesis of natural products.

  15. Novel Euglenoid Derived Alkaloid

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Disclosed herein is a purified toxin isolated from Euglena sanguinea. More specifically the toxin, termed euglenophycin, is an alkaloid having herbicidal and...

  16. Occurrence of halogenated alkaloids.

    Science.gov (United States)

    Gribble, Gordon W

    2012-01-01

    Once considered to be isolation artifacts or chemical "mistakes" of nature, the number of naturally occurring organohalogen compounds has grown from a dozen in 1954 to >5000 today. Of these, at least 25% are halogenated alkaloids. This is not surprising since nitrogen-containing pyrroles, indoles, carbolines, tryptamines, tyrosines, and tyramines are excellent platforms for biohalogenation, particularly in the marine environment where both chloride and bromide are plentiful for biooxidation and subsequent incorporation into these electron-rich substrates. This review presents the occurrence of all halogenated alkaloids, with the exception of marine bromotyrosines where coverage begins where it left off in volume 61 of The Alkaloids. Whereas the biological activity of these extraordinary compounds is briefly cited for some examples, a future volume of The Alkaloids will present full coverage of this topic and will also include selected syntheses of halogenated alkaloids. Natural organohalogens of all types, especially marine and terrestrial halogenated alkaloids, comprise a rapidly expanding class of natural products, in many cases expressing powerful biological activity. This enormous proliferation has several origins: (1) a revitalization of natural product research in a search for new drugs, (2) improved compound characterization methods (multidimensional NMR, high-resolution mass spectrometry), (3) specific enzyme-based and other biological assays, (4) sophisticated collection methods (SCUBA and remote submersibles for deep ocean marine collections), (5) new separation and purification techniques (HPLC and countercurrent separation), (6) a greater appreciation of traditional folk medicine and ethobotany, and (7) marine bacteria and fungi as novel sources of natural products. Halogenated alkaloids are truly omnipresent in the environment. Indeed, one compound, Q1 (234), is ubiquitous in the marine food web and is found in the Inuit from their diet of whale

  17. Contemporary Strategies for the Synthesis of Tetrahydropyran Derivatives: Application to Total Synthesis of Neopeltolide, a Marine Macrolide Natural Product

    Science.gov (United States)

    Fuwa, Haruhiko

    2016-01-01

    Tetrahydropyrans are structural motifs that are abundantly present in a range of biologically important marine natural products. As such, significant efforts have been paid to the development of efficient and versatile methods for the synthesis of tetrahydropyran derivatives. Neopeltolide, a potent antiproliferative marine natural product, has been an attractive target compound for synthetic chemists because of its complex structure comprised of a 14-membered macrolactone embedded with a tetrahydropyran ring, and twenty total and formal syntheses of this natural product have been reported so far. This review summarizes the total and formal syntheses of neopeltolide and its analogues, highlighting the synthetic strategies exploited for constructing the tetrahydropyran ring. PMID:27023567

  18. Marine Indole Alkaloids

    Directory of Open Access Journals (Sweden)

    Natalie Netz

    2015-08-01

    Full Text Available Marine indole alkaloids comprise a large and steadily growing group of secondary metabolites. Their diverse biological activities make many compounds of this class attractive starting points for pharmaceutical development. Several marine-derived indoles were found to possess cytotoxic, antineoplastic, antibacterial and antimicrobial activities, in addition to the action on human enzymes and receptors. The newly isolated indole alkaloids of marine origin since the last comprehensive review in 2003 are reported, and biological aspects will be discussed.

  19. A Pot-Economical Approach to the Total Synthesis of Sch-725674.

    Science.gov (United States)

    Bodugam, Mahipal; Javed, Salim; Ganguly, Arghya; Torres, Jessica; Hanson, Paul R

    2016-02-01

    A pot-economical total synthesis of antifungal Sch-725674, 1, is reported. The approach takes advantage of a number of one-pot, sequential transformations, including a phosphate tether-mediated one-pot, sequential RCM/CM/chemoselective hydrogenation protocol, a one-pot tosylation/acrylation sequence, and a one-pot, sequential Finkelstein reaction/Boord olefination/acetonide deprotection procedure to streamline the synthesis route by reducing isolation and purification procedures, thus saving time. Overall, an asymmetric route has been developed that is efficiently accomplished in seven pots from phosphate (S,S)-triene and with minimal purification. PMID:26760683

  20. The Total Synthesis of Insect Antifeedant (-)-Dihydroclerodin Starting from R-(-)-Carvone

    OpenAIRE

    Meulemans, T.M.

    2000-01-01

    The first total synthesis of the natural enantiomer of the insect-antifeedant dihydroclerodin ( 1 ) and lupulin C ( 268 ) has been achieved in 18 and 17 steps respectively starting from R-(-)-carvone ( 2 ). A new strategy was developed in which the hexahydrofuro[2,3- b ]furan fragment was introduced in the beginning of the synthesis, via a remarkably diastereoselective Mukaiyama reaction of silyl enol ether 135 with 2-methoxy-hexahydrofuro[2,3- b ]furan ( 156 ), which gave only two of the pos...

  1. The background of the total synthesis of yeast alanine transfer RNA

    Institute of Scientific and Technical Information of China (English)

    QI GuoRong

    2010-01-01

    @@ The research findings concerning the total synthesis of yeast alanine transfer RNA (yeast alanine tRNA) were successively published in Chinese Science Bulletin (1982) and Science in China (1983) [1].The research work started in 1968 and was finished in November 1981.It was the first artificial synthesis of a nucleic acid molecule, which followed the first artificial synthesis of protein, crystalline bovine insulin, in China in 1965, both scientific milestones occurring in China.The composition, sequence and biological functions of the synthesized nucleic acid were identical to those of the natural yeast alanine tRNA.The research lasted for 13 years.From 1982 to 1984, one of the investigators in charge of the research Prof.

  2. Stereoselective first total synthesis, confirmation of the absolute configuration and bioevaluation of botryolide-E.

    Science.gov (United States)

    Reddy, D Kumar; Shekhar, V; Prabhakar, P; Babu, D Chanti; Ramesh, D; Siddhardha, B; Murthy, U S N; Venkateswarlu, Y

    2011-02-01

    A simple, first stereoselective total synthesis of botryolide-E has been described. The synthesis started from propylene oxide employing Jacobsen's hydrolytic kinetic resolution (HKR), selective epoxide opening, sharpless asymmetric dihydroxylation, one pot acetonide deprotection and lactonization as key steps. Further, the synthesis confirms the absolute configuration of the natural product botryolide-E and we evaluated the biological behavior of natural product botryolide-E against a panel of bacteria and fungi. Botryolide-E exhibits significant potent activity against Staphylococcus aureus (MTCC 96) (6.25 μg/ml), good against Escherichia coli (MTCC 443) (12.5 μg/ml), Bacillus subtilis (MTCC 441) (25 μg/ml) and compound 1 exhibited good to moderate antifungal activity. PMID:21211971

  3. Total Synthesis of Chiral Biaryl Natural Products by Asymmetric Biaryl Coupling ‡

    OpenAIRE

    Kozlowski, Marisa C.; Morgan, Barbara J.; Linton, Elizabeth C.

    2009-01-01

    This tutorial review highlights the use of catalytic asymmetric 2-naphthol couplings in total synthesis. The types of chirality, chiral biaryl natural products, prior approaches to chiral biaryl natural products, and other catalytic asymmetric biaryl couplings are outlined. The three main categories of chiral catalysts for 2-naphthol coupling (Cu, V, Fe) are described with discussion of their limitations and advantages. Applications of the copper catalyzed couplings in biomimetic syntheses ar...

  4. Studies towards the total synthesis of eleutherobin and other marine natural products

    OpenAIRE

    Mowat, Jeffrey Stuart

    2012-01-01

    The primary focus of the research described in this document relates to the development and application of new synthetic methodologies relevant for the concise construction of four natural products. In Chapter 2, a discussion of our investigation of the total synthesis of eleutherobin (1) is disclosed. Eleutherobin (1), first isolated in 1997 from the rare soft coral Eleutherobia sp., is a member of a class of microtubule stabilising natural products. Although it displays potent cytotoxicity,...

  5. Recent Advances in the Total Synthesis of Tetramic Acid-Containing Natural Products

    OpenAIRE

    Wen-Ju Bai; Chen Lu; Xiqing Wang

    2016-01-01

    With incredible bioactivities and fascinating structural complexities, tetramic acid- (TA-) containing natural products have attracted favorable attention among the organic chemistry community. Although the construction of the TA core is usually straightforward, the intricate C3-side chain sometimes asks for some deliberative strategy so as to fulfill an elegant total synthesis. This review mainly covers some exceptional synthetic examples for each type of natural product in recent years, sho...

  6. Total synthesis of the endogenous inflammation resolving lipid resolvin D2 using a common lynchpin

    OpenAIRE

    John Li; May May Leong; Alastair Stewart; Mark A. Rizzacasa

    2013-01-01

    The total synthesis of the endogenous inflammation resolving eicosanoid resolvin D2 (1) is described. The key steps involved a Wittig reaction between aldehyde 5 and the ylide derived from phosphonium salt 6 to give enyne 17 and condensation of the same ylide with aldehyde 7 to afford enyne 11. Desilylation of 11 followed by hydrozirconation and iodination gave the vinyl iodide 4 and Sonogashira coupling between this compound and enyne 3 provided alkyne 18. Acetonide deprotection, partial red...

  7. Total synthesis of (+)-discodermolide: a highly convergent fourth-generation approach.

    Science.gov (United States)

    Smith, Amos B; Freeze, B Scott; Xian, Ming; Hirose, Tomoyasu

    2005-04-28

    [structure: see text] A highly convergent, fourth-generation total synthesis of (+)-discodermolide (1), with a longest linear sequence of 17 steps and an overall yield of 9.0%, has been achieved. Highlighting the strategy is the efficient construction and sequential, bidirectional union of a linchpin comprising the C(9)-C(14) Wittig salt-vinyl iodide (-)-18. Importantly, Wittig salt generation proceeded in excellent yield under ambient pressure.

  8. Design, total synthesis, and evaluation of C13-C14 cyclopropane analogues of (+)-discodermolide.

    Science.gov (United States)

    Smith, Amos B; Xian, Ming; Liu, Fenghua

    2005-10-13

    [structure: see text] The design, total synthesis, and biological evaluation of two C13-C14-cyclopropyl analogues [(+)-1 and (+)-2] of (+)-discodermolide have been achieved. Key features of the syntheses include highly stereoselective, hydroxyl-directed cyclopropanations of vinyl iodides and higher order cuprate-mediated cross-coupling reactions between cyclopropyl iodides and alkyl iodides. Biological evaluation revealed that neither orientation of the cyclopropyl methylene completely substitutes for the C14 methyl found in (+)-discodermolide (3).

  9. First total synthesis of the marine natural products clavulolactones II and III.

    Science.gov (United States)

    Miller, Charlotte M; Benneche, Tore; Tius, Marcus A

    2015-04-01

    The first total synthesis of the marine prostanoids clavulolactones II and III is presented from an easily accessible chiral, non-racemic cyclopentenone intermediate. Key steps involve selective TBDMS deprotection, selective reduction of the β-side chain and aldol condensation. Clavulolactones II and III were successfully prepared from (S)-4-((tert-butyldimethylsilyl)oxy) cyclopent-2-en-1-one over nine steps, in overall yields of 21 and 7% respectively. PMID:25733336

  10. Total Synthesis of (±)-Paroxetine by Diastereoconvergent Cobalt-Catalysed Arylation

    OpenAIRE

    Despiau, Carole F; Dominey, Andrew P; Harrowven, David C.; Linclau, Bruno

    2014-01-01

    A total synthesis of paroxetine is reported, with a diastereoselective and diastereoconvergent cobalt-catalysed sp3–sp2 coupling reaction involving a 3-substituted 4-bromo-N-Boc-piperidine (Boc = tert-butoxycarbonyl) substrate as a key step. A 9:1 diastereoselectivity was obtained, while a control experiment involving a conformationally locked 3-substituted 4-bromo-tert-butyl cyclohexane ring proceeded with essentially complete stereoselectivity.

  11. CRINUM; AN ENDLESS SOURCE OF BIOACTIVE PRINCIPLES: A REVIEW. PART 1- CRINUM ALKALOIDS: LYCORINE-TYPE ALKALOIDS

    Directory of Open Access Journals (Sweden)

    John Refaat*, Mohamed S. Kamel , Mahmoud A. Ramadan and Ahmed A. Ali

    2012-07-01

    Full Text Available Crinum is an important Amaryllidaceous plant thanks to the valuable biological and therapeutic activities of its chemical constituents, especially alkaloids. Many Crinum species have been commonly used in traditional medicines worldwide. Long ago, they have been subjected to extensive chemical, cytological and pharmacological investigations. Accordingly, this work comprehensively comprises both the alkaloidal and non-alkaloidal principles of Crinums isolated from 1950 and up to now, together with various biological and toxicological studies conducted on both the total extracts and individual compounds. As being a major common class of Crinum alkaloids, the current part of this review work highlights the lycorine-type alkaloids isolated so far from this plant in addition to their distribution in different Crinum species.

  12. Polymer-Supported Cinchona Alkaloid-Derived Ammonium Salts as Recoverable Phase-Transfer Catalysts for the Asymmetric Synthesis of α-Amino Acids

    Directory of Open Access Journals (Sweden)

    Carmen Nájera

    2004-04-01

    Full Text Available Alkaloids such as cinchonidine, quinine and N-methylephedrine have been N-alkylated using polymeric benzyl halides or co-polymerized and then N-alkylated, thus affording a series of polymer-supported chiral ammonium salts which have been employed as phase-transfer catalysts in the asymmetric benzylation of an N-(diphenylmethyleneglycine ester. These new polymeric catalysts can be easily recovered by simple filtration after the reaction and reused. The best ee’s were achieved when Merrifield resin-anchored cinchonidinium ammonium salts were employed.

  13. Analysis of Ergot Alkaloids

    Directory of Open Access Journals (Sweden)

    Colin Crews

    2015-06-01

    Full Text Available The principles and application of established and newer methods for the quantitative and semi-quantitative determination of ergot alkaloids in food, feed, plant materials and animal tissues are reviewed. The techniques of sampling, extraction, clean-up, detection, quantification and validation are described. The major procedures for ergot alkaloid analysis comprise liquid chromatography with tandem mass spectrometry (LC-MS/MS and liquid chromatography with fluorescence detection (LC-FLD. Other methods based on immunoassays are under development and variations of these and minor techniques are available for specific purposes.

  14. Natural Product Total Synthesis in the Organic Laboratory: Total Synthesis of Caffeic Acid Phenethyl Ester (CAPE), a Potent 5-Lipoxygenase Inhibitor from Honeybee Hives

    Science.gov (United States)

    Touaibia, Mohamed; Guay, Michel

    2011-01-01

    Natural products play a critical role in modern organic synthesis and learning synthetic techniques is an important component of the organic laboratory experience. In addition to traditional one-step organic synthesis laboratories, a multistep natural product synthesis is an interesting experiment to challenge students. The proposed three-step…

  15. Total Synthesis, Structure Revision, and Absolute Configuration of (−)-Brevenal

    Science.gov (United States)

    Fuwa, Haruhiko; Ebine, Makoto; Bourdelais, Andrea J.; Baden, Daniel G.; Sasaki, Makoto

    2008-01-01

    Total synthesis of structure 1 originally proposed for brevenal, a nontoxic polycyclic ether natural product isolated from the Florida red tide dinoflagellate, Karenia brevis, was accomplished. The key features of the synthesis involved (i) convergent assembly of the pentacyclic polyether skeleton based on our developed Suzuki–Miyaura coupling chemistry and (ii) stereoselective construction of the multi-substituted (E,E)-dienal side chain by using copper(I) thiophen-2-carboxylate (CuTC)-promoted modified Stille coupling. The disparity of NMR spectra between the synthetic material and the natural product required a revision of the proposed structure. Detailed spectroscopic comparison of synthetic 1 with natural brevenal, coupled with the postulated biosynthetic pathway for marine polyether natural products, suggested that the natural product was most likely represented by 2, the C26 epimer of the proposed structure 1. The revised structure was finally validated by completing the first total synthesis of (−)-2, which also unambiguously established the absolute configuration of the natural product. PMID:17177450

  16. Toward the Enantioselective Total Synthesis of Lyngbyatoxin A: On the Stereocontrolled Introduction of the Quaternary Stereogenic Centre

    DEFF Research Database (Denmark)

    Tønder, Janne Ejrnæs; Tanner, David Ackland

    2003-01-01

    This paper deals with an approach to the enantioselective total synthesis of Lyngbyatoxin A, with focus on the stereocontrolled introduction of the quaternary stereogenic centre. The key step in the synthesis involves an enantiospecific Lewis-acid mediated rearrangement of chiral vinyl epoxides c...

  17. Main Alkaloids of Peganum harmala L. and Their Different Effects on Dicot and Monocot Crops

    OpenAIRE

    Chi Zhang; Yuanming Zhang; Hua Shao; Xiaoli Huang

    2013-01-01

    Alkaloids with allelopathic activity are not as well-known as other allelochemicals. Our study revealed that total alkaloids from seeds of the medicinal plant Peganum harmala L. possessed significant growth inhibitory effect on four treated plants, with dicot plants (lettuce and amaranth) being more sensitive than the tested monocot plants (wheat and ryegrass). Further investigation led to the isolation of harmaline and harmine as the main active ingredients in the total alkaloids of P. harma...

  18. Recent Advances in the Total Synthesis of Tetramic Acid-Containing Natural Products

    Directory of Open Access Journals (Sweden)

    Wen-Ju Bai

    2016-01-01

    Full Text Available With incredible bioactivities and fascinating structural complexities, tetramic acid- (TA- containing natural products have attracted favorable attention among the organic chemistry community. Although the construction of the TA core is usually straightforward, the intricate C3-side chain sometimes asks for some deliberative strategy so as to fulfill an elegant total synthesis. This review mainly covers some exceptional synthetic examples for each type of natural product in recent years, showcasing the great achievements as well as unsettled obstacles in this area, in the hope of accelerating the synthetic and biological investigations for this unique type of natural product.

  19. Total synthesis of leopolic acid A, a natural 2,3-pyrrolidinedione with antimicrobial activity

    Science.gov (United States)

    Dhavan, Atul A; Kaduskar, Rahul D; Musso, Loana; Scaglioni, Leonardo; Martino, Piera Anna

    2016-01-01

    Summary The first total synthesis of leopolic acid A, a fungal metabolite with a rare 2,3-pyrrolidinedione nucleus linked to an ureido dipeptide, was designed and carried out. Crucial steps for the strategy include a Dieckmann cyclization to obtain the 2,3-pyrrolidinedione ring and a Wittig olefination to install the polymethylene chain. An oxazolidinone-containing leopolic acid A analogue was also synthesized. The antibacterial activity showed by both compounds suggests that they could be considered as promising candidates for future developments. PMID:27559415

  20. Total Synthesis of Fellutamide B and Deoxy-Fellutamides B, C, and D

    Directory of Open Access Journals (Sweden)

    Richard J. Payne

    2013-07-01

    Full Text Available The total syntheses of the marine-derived lipopeptide natural product fellutamide B and deoxy-fellutamides B, C, and D are reported. These compounds were accessed through a novel solid-phase synthetic strategy using Weinreb amide-derived resin. As part of the synthesis, a new enantioselective route to (3R-hydroxy lauric acid was developed utilizing a Brown allylation reaction followed by an oxidative cleavage-oxidation sequence as the key steps. The activity of these natural products, and natural product analogues was also assessed against Mycobacterium tuberculosis in vitro.

  1. An approach to seco-prezizaane sesquiterpenoids: enantioselective total synthesis of (+)-1S-minwanenone.

    Science.gov (United States)

    Mehta, Goverdhan; Shinde, Harish M

    2012-09-21

    A strategy of general applicability toward seco-prezizaane sesquiterpenes, from a chiral, tricyclic synthon, readily available via an enzymatic resolution step from the Diels-Alder adduct of cyclopentadiene and p-benzoquinone, has been devised. Our approach enables harnessing of the stereochemical proclivities of the norbornyl system to install the desired stereochemistry at the key stereogenic centers. Recourse to an interesting stratagem to realign a stereochemical divergence into stereoreconvergence forms the cornerstone of our successful approach. The first total synthesis of (+)-1S-minwanenone, a prototypical member of seco-prezizaane subclass, has been accomplished. PMID:22897237

  2. Total synthesis of the endogenous inflammation resolving lipid resolvin D2 using a common lynchpin

    Directory of Open Access Journals (Sweden)

    John Li

    2013-12-01

    Full Text Available The total synthesis of the endogenous inflammation resolving eicosanoid resolvin D2 (1 is described. The key steps involved a Wittig reaction between aldehyde 5 and the ylide derived from phosphonium salt 6 to give enyne 17 and condensation of the same ylide with aldehyde 7 to afford enyne 11. Desilylation of 11 followed by hydrozirconation and iodination gave the vinyl iodide 4 and Sonogashira coupling between this compound and enyne 3 provided alkyne 18. Acetonide deprotection, partial reduction and ester hydrolysis then gave resolvin D2 (1.

  3. Total synthesis of leopolic acid A, a natural 2,3-pyrrolidinedione with antimicrobial activity

    Science.gov (United States)

    Dhavan, Atul A; Kaduskar, Rahul D; Musso, Loana; Scaglioni, Leonardo; Martino, Piera Anna

    2016-01-01

    Summary The first total synthesis of leopolic acid A, a fungal metabolite with a rare 2,3-pyrrolidinedione nucleus linked to an ureido dipeptide, was designed and carried out. Crucial steps for the strategy include a Dieckmann cyclization to obtain the 2,3-pyrrolidinedione ring and a Wittig olefination to install the polymethylene chain. An oxazolidinone-containing leopolic acid A analogue was also synthesized. The antibacterial activity showed by both compounds suggests that they could be considered as promising candidates for future developments.

  4. First total synthesis of 10α-hydroxy-4-muurolen-3-one and its C10-isomer

    Institute of Scientific and Technical Information of China (English)

    Fu Qiang Bi; Li Jing Fang; Chen Xi Zhang; Yu Lin Li

    2008-01-01

    An efficient synthetic route to muurolane type sesquiterpenes starting from (R)-carvone,employing allylic diazene rearrange-ment and the ring closing methesis (RCM) reaction as key steps,is described.The first asymmetric total synthesis of (-)-10α-hydroxy-4-muurolen-3-one B and (-)-10β-hydroxy-4-muurolen-3-one C was accomplished.Through the total synthesis,the absolute configurations of the natural products A,B and C were established.

  5. Synthetic and Receptor Signaling Explorations of the Mitragyna Alkaloids: Mitragynine as an Atypical Molecular Framework for Opioid Receptor Modulators.

    Science.gov (United States)

    Kruegel, Andrew C; Gassaway, Madalee M; Kapoor, Abhijeet; Váradi, András; Majumdar, Susruta; Filizola, Marta; Javitch, Jonathan A; Sames, Dalibor

    2016-06-01

    Mu-opioid receptor agonists represent mainstays of pain management. However, the therapeutic use of these agents is associated with serious side effects, including potentially lethal respiratory depression. Accordingly, there is a longstanding interest in the development of new opioid analgesics with improved therapeutic profiles. The alkaloids of the Southeast Asian plant Mitragyna speciosa, represented by the prototypical member mitragynine, are an unusual class of opioid receptor modulators with distinct pharmacological properties. Here we describe the first receptor-level functional characterization of mitragynine and related natural alkaloids at the human mu-, kappa-, and delta-opioid receptors. These results show that mitragynine and the oxidized analogue 7-hydroxymitragynine, are partial agonists of the human mu-opioid receptor and competitive antagonists at the kappa- and delta-opioid receptors. We also show that mitragynine and 7-hydroxymitragynine are G-protein-biased agonists of the mu-opioid receptor, which do not recruit β-arrestin following receptor activation. Therefore, the Mitragyna alkaloid scaffold represents a novel framework for the development of functionally biased opioid modulators, which may exhibit improved therapeutic profiles. Also presented is an enantioselective total synthesis of both (-)-mitragynine and its unnatural enantiomer, (+)-mitragynine, employing a proline-catalyzed Mannich-Michael reaction sequence as the key transformation. Pharmacological evaluation of (+)-mitragynine revealed its much weaker opioid activity. Likewise, the intermediates and chemical transformations developed in the total synthesis allowed the elucidation of previously unexplored structure-activity relationships (SAR) within the Mitragyna scaffold. Molecular docking studies, in combination with the observed chemical SAR, suggest that Mitragyna alkaloids adopt a binding pose at the mu-opioid receptor that is distinct from that of classical opioids. PMID

  6. Aporphine alkaloid contents increase with moderate nitrogen supply in Annona diversifolia Saff. (Annonaceae) seedlings during diurnal periods.

    Science.gov (United States)

    Orozco-Castillo, José Agustín; Cruz-Ortega, Rocío; Martinez-Vázquez, Mariano; González-Esquinca, Alma Rosa

    2016-10-01

    Aporphine alkaloids are secondary metabolites that are obtained in low levels from species of the Annonaceae family. Nitrogen addition may increase the alkaloid content in plants. However, previous studies published did not consider that nitrogen could change the alkaloid content throughout the day. We conducted this short-term study to determine the effects of nitrogen applied throughout the diurnal period on the aporphine alkaloids via measurements conducted on the roots, stems and leaves of Annona diversifolia seedlings. The 60-day-old seedlings were cultured with the addition of three levels of nitrogen (0, 30 and 60 mM), and alkaloid extracts were analysed using high-performance liquid chromatography. The highest total alkaloid content was measured in the treatment with moderate nitrogen supply. Further, the levels of aporphine alkaloids changed significantly in the first few hours of the diurnal period. We conclude that aporphine alkaloid content increased with moderate nitrogen supply and exhibited diurnal variation.

  7. Relativity among starch quantity, polysaccharides content and total alkaloid content of Dendrobium loddigesii%美花石斛茎的淀粉粒数量、多糖含量与生物碱含量的相关性研究

    Institute of Scientific and Technical Information of China (English)

    朱华; 滕建北; 蔡毅; 梁洁; 朱意麟; 韦韬

    2011-01-01

    目的:研究美花石斛茎的淀粉粒数量、多糖含量、生物碱含量之间的相关性.方法:显微计数法统计茎的淀粉粒数量,硫酸-蒽酮比色法测定多糖含量,溴甲酚绿比色法测定生物碱含量;Pearson积差相关分析、Kendall's等级相关分析、Spearman’s和谐系数分析研究三者的相关性.结果与结论:美花石斛茎的淀粉粒数量与其多糖含量有极显著的正相关性,而淀粉粒数量及多糖含量均与生物碱含量呈显著的负相关性.%Objective; To find out the relativity among starch quantity, polysaccharides content and total alkaloid content of Dendrobium loddigesii. Method: Microscopy-counting process was applied to starch quantity statistics, sulfuric acid-anthrone colorime-try was used to assay polysaccharides content and bromocresol green colorimetry was used to assay alkaloid content Pearson product moment correlation analysis, Kendall's rank correlation analysis and Spearman's concordance coefficient analysis were applied to study their relativity. Result and Conclusion: Extremely significant positive correlation was found between starch quantity and polysaccharides content, and significant negative correlation between alkaloid content and starch quantity was discovered, as well was between alkaloid content and polysaccharides content

  8. Synthesis of derivatives of tetronic acid and pulvinic acid. Total synthesis of norbadione A; Synthese de derives de l'acide tetronique et de l'acide pulvinique. Synthese totale de la norbadione A

    Energy Technology Data Exchange (ETDEWEB)

    Mallinger, A

    2008-11-15

    When vegetables like mushrooms are contaminated by radioactive caesium 137, this radioactive caesium is associated to norbadione A, a natural pigment present in two mushroom species and which can be used as a caesium decorporation agent or maybe as protection agent against ionizing radiations. Within this perspective, this research report describes the biosynthesis and the structure and properties of the norbadione A and of pulvinic acids (physicochemical properties, anti-oxidizing properties). Then, it presents the various tetronic acids (3-acyl-, 3-alkyl-, 3-alkoxy-, 3-aryl-tetronic acids and non 3-substituted tetronic acids), their synthesis path as they are described in the literature, and presents a new synthesis approach using a tandem reaction (with different esters or hydroxy esters) and the synthesis of tetronic acids. The author also proposes a new synthesis way for methyl pulvinates, and finally reports the work on the development of a total synthesis of the norbadione A.

  9. An analysis of Sorghum halepense’s behavior in presence of tropane alkaloids from Datura stramonium extracts

    OpenAIRE

    Butnariu Monica

    2012-01-01

    Abstract Background This study aimed to quantify the allelopathic potential of Datura stramonium (Jimson weed). Sorghum halepense (Johnsongrass) tolerance was assessed by germinating, seed and growing seedlings, dosing of photo-synthesis pigments, followed by treatment with D. stramonium extract tropane alkaloids. Results Preliminary chemical analysis of the extracts showed the presence of alkaloids. The presence of alkaloids was confirmed through HPLC–UV system analysis. Various concentratio...

  10. Decision-making regarding total knee replacement surgery: A qualitative meta-synthesis

    Directory of Open Access Journals (Sweden)

    Ong Bie

    2007-04-01

    Full Text Available Abstract Background Knee osteoarthritis is a highly prevalent condition that can result in disability and reduced quality of life. The evidence suggests that total knee replacement surgery (TKR is an effective intervention for patients with severe knee problems, but there is also an unmet need for this treatment in the UK. To help understand the reason for this unmet need, the aim of this study was to explore the factors that influence the decision-making process of TKR surgery by synthesising the available evidence from qualitative research on this topic. Methods A meta-synthesis was undertaken. This involved sevens steps: getting started, deciding what is relevant to the initial interest, reading the studies, determining how the studies are related, translating the studies into one another, synthesising translations, and finally, expressing the synthesis. Second-order and third-order interpretations regarding decision-making in TKR surgery were drawn from the literature. Results Ten qualitative studies were found and are included in the synthesis. The evidence suggests that social and cultural categories of aging have shaped the expectation of knee osteoarthritis, and this in turn shapes patients' expectations of treatment options. The role of the health care professional was the strongest theme to emerge across all ten studies. Coping strategies and life context determine short and longer-term outcomes of TKR. Conclusion The decision-making process regarding TKR surgery is extremely complex, as patients have weigh up numerous considerations before they can make a decision about surgery. By synthesising ten qualitative studies, we have illuminated the importance of the health care professional during this process.

  11. Total Synthesis of Flocoumafen via Knoevenagel Condensation and Intramolecular Ring Cyclization: General Access to Natural Products

    Directory of Open Access Journals (Sweden)

    Mankil Jung

    2012-02-01

    Full Text Available The total synthesis and structure determination of cis- and trans-flocoumafen was described. The key synthetic steps involve Knoevenagel condensation with p-methoxybenzaldehyde, in situ decarboxylation and intramolecular ring cyclization to construct the tetralone skeleton. Stereospecific reduction of the O-alkylated ketone 13 afforded good yield of precusor alcohol 5. Final coupling of alcohol 5 with 4-hydroxy-coumarin yielded flocoumafen (1. Separation and structure determination of cis- and trans-flocoumafen through 2D NMR analyses-assisted computer simulation techniques for the evaluation of anticoagulant activities are reported for the first time. This method is useful for generating the core tetralone skeleton of 4-hydroxycoumarin derivatives and provides a generalized access to various warfarin type anticoagulants.

  12. Total Synthesis and Antifungal Activity of Palmarumycin CP17 and Its Methoxy Analogues.

    Science.gov (United States)

    Wang, Ruina; Liu, Guoyue; Yang, Mingyan; Wang, Mingan; Zhou, Ligang

    2016-01-01

    Total synthesis of naturally occurring spirobisnaphthalene palmarumycin CP17 and its methoxy analogues was first achieved through Friedel-Crafts acylation, Wolff-Kishner reduction, intramolecular cyclization, ketalization, benzylic oxidation, and demethylation using the inexpensive and readily available methoxybenzene, 1,2-dimethoxybenzene and 1,4-dimethoxybenzene and 1,8-dihydroxynaphthalene as raw materials. Demethylation with (CH₃)₃SiI at ambient temperature resulted in ring A aromatization and acetal cleavage to give rise to binaphthyl ethers. The antifungal activities of these spirobisnaphthalene derivatives were evaluated, and the results revealed that 5 and 9b exhibit EC50 values of 9.34 µg/mL and 12.35 µg/mL, respectively, against P. piricola. PMID:27164077

  13. Total Synthesis and Antifungal Activity of Palmarumycin CP17 and Its Methoxy Analogues

    Directory of Open Access Journals (Sweden)

    Ruina Wang

    2016-05-01

    Full Text Available Total synthesis of naturally occurring spirobisnaphthalene palmarumycin CP17 and its methoxy analogues was first achieved through Friedel-Crafts acylation, Wolff-Kishner reduction, intramolecular cyclization, ketalization, benzylic oxidation, and demethylation using the inexpensive and readily available methoxybenzene, 1,2-dimethoxybenzene and 1,4-dimethoxybenzene and 1,8-dihydroxynaphthalene as raw materials. Demethylation with (CH33SiI at ambient temperature resulted in ring A aromatization and acetal cleavage to give rise to binaphthyl ethers. The antifungal activities of these spirobisnaphthalene derivatives were evaluated, and the results revealed that 5 and 9b exhibit EC50 values of 9.34 µg/mL and 12.35 µg/mL, respectively, against P. piricola.

  14. Total Synthesis and Anti-Viral Activities of an Extract of Radix isatidis

    Directory of Open Access Journals (Sweden)

    Li-Wei He

    2014-12-01

    Full Text Available Radix isatidis (Banlangen, a famous traditional Chinese medicine, has been used for thousands of years in China due to its anti-viral activity. Through our research, we inferred that the anti-viral activity of Radix isatidis depended on the water-soluble part. Among the components of this extract, the isoquinoline derivative 1 was isolated for the first time and has shown better anti-viral activity than other constituents. In this study, to solve the problem of sourcing sufficient quantities of compound 1, a total synthesis route is described, and several analogues are also evaluated for their anti-viral activities. Among them, compound 8 shown potent anti-viral activity with an IC50 value of 15.3 µg/mL. The results suggested that isoquinoline derivatives possessed potent anti-viral activity and are worthy further development.

  15. INHIBITORY EFFECTS OF THE ALKALOIDS FROM Radix Caulophylli ON THE PROLIFERATION OF HUMAN VASCULAR ENDOTHELIAL CELL

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective To find an angiogenetic inhibitor from Radix Caulophylli (RC). Methods The extract of Radix Caulophylli was obtained by using 95% alcohol in water as solvent. Then, the total alkaloids of Radix Caulophylli was isolated from the extract by using a positive ion exchange resin column. An active part was found by a screening model of cell membrane chromatography (CMC) and further tested by the MTT method with emodin as a control. Results The total alkaloids of Radix Caulophylli was the active part by CMC and could significantly inhibit proliferation of ECV304 cells in MTT test. The inhibitory rate was 56.06% while the concentration of the total alkaloids of Radix Caulophylli was 19.63μg/mL. Conclusion The total alkaloids from Radix Caulophylli may be a new angiogenetic inhibitor, and mechanism of the total alkaloids on inhibitory angiogenesis still need to be further investigated.

  16. Stereoselective Total Synthesis of Atractylodemayne A, a Conjugated 2(E),8(Z),10(E)-Triene-4,6-diyne.

    Science.gov (United States)

    Schmidt, Bernd; Audörsch, Stephan

    2016-03-01

    The first total synthesis of the polyacetylene natural product atractylodemayne A is reported. Stereoselective construction of the conjugated 8(Z),10(E)-diene moiety was achieved through a tethered ring-closing metathesis approach, comprising a Ru-catalyzed RCM followed by a base-induced elimination. A Pd-catalyzed Cadiot-Chodkiewicz coupling was used for the synthesis of the diyne. Overall, atractylodemayne A was synthesized in nine steps for the longest linear sequence. PMID:26886865

  17. Peloruside B, a Potent Antitumor Macrolide from the New Zealand Marine Sponge Mycale hentscheli: Isolation, Structure, Total Synthesis and Bioactivity

    OpenAIRE

    Singh, A. Jonathan; Xu, Chun-Xiao; Xu, Xiaoming; West, Lyndon M.; Wilmes, Anja; Chan, Ariane; Hamel, Ernest; John H Miller; Peter T. Northcote; Ghosh, Arun K.

    2010-01-01

    Peloruside B (2), a natural congener of peloruside A (1), was isolated in sub-milligram quantities from the New Zealand marine sponge Mycale hentscheli. Peloruside B promotes microtubule polymerization and arrests cells in the G2M phase of mitosis similar to paclitaxel, and its bioactivity was comparable to that of peloruside A. NMR-directed isolation, structure elucidation, structure confirmation by total synthesis and bioactivity of peloruside B are described in this article. The synthesis ...

  18. Total synthesis and structural revision of vannusals A and B: synthesis of the originally assigned structure of vannusal B.

    Science.gov (United States)

    Nicolaou, K C; Ortiz, Adrian; Zhang, Hongjun; Dagneau, Philippe; Lanver, Andreas; Jennings, Michael P; Arseniyadis, Stellios; Faraoni, Raffaella; Lizos, Dimitrios E

    2010-05-26

    The total synthesis of the originally assigned structure of vannusal B (2) and its diastereomer (d-2) are described. Initial forays into these structures with model systems revealed the viability of a metathesis-based approach and a SmI(2)-mediated strategy for the key cyclization to forge the central region of the molecule, ring C. The former approach was abandoned in favor of the latter when more functionalized substrates failed to enter the cyclization process. The successful, devised convergent strategy based on the SmI(2)-mediated ring closure utilized vinyl iodide (-)-26 and aldehyde fragment (+/-)-86 as key building blocks, whose lithium-mediated coupling led to isomeric coupling products (+)-87 and (-)-88 (as shown in Scheme 17 in the article). Intermediate (-)-88 was converted, via (-)-89 and (-)-90/(+)-91, to vannusal B structure 2 (as shown in Scheme 18 in the article), whose spectroscopic data did not match those reported for the natural product. Similarly, intermediate (+)-25, obtained through coupling of vinyl iodide (-)-26 and aldehyde (+/-)-27 (as shown in Scheme 13 in the article) was transformed via intermediates (-)-97 and (+)-98 (as shown in Scheme 19 in the article) to diastereomeric vannusal B structure (+)-d-2 (as shown in Scheme 19 in the article) which was also proven spectroscopically to be non-identical to the naturally occurring substance. These investigations led to the discovery and development of a number of new synthetic technologies that set the stage for the solution of the vannusal structural conundrum. PMID:20443561

  19. Solid-phase extraction and LC-MS analysis of pyrrolizidine alkaloids in honeys.

    Science.gov (United States)

    Beales, Kerrie A; Betteridge, Keith; Colegate, Steven M; Edgar, John A

    2004-10-20

    Strong-cation-exchange, solid-phase extraction of pyrrolizidine alkaloids and their N-oxides from honey samples was followed by reduction of the N-oxides and subsequent analysis of total pyrrolizidine alkaloids using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. A limited survey of 63 preprocessing samples of honey, purposefully biased toward honeys attributed to floral sources known to produce pyrrolizidine alkaloids, demonstrated levels of pyrrolizidine alkaloids up to approximately 2000 parts per billion (ppb) in a sample attributed to Echium plantagineum. Up to 800 ppb pyrrolizidine alkaloids was detected in some honeys not attributed by the collector to any pyrrolizidine alkaloid-producing floral source. No pyrrolizidine alkaloids were detected in approximately 30% of the samples in this limited study, while some honeys showed the copresence of pyrrolizidine alkaloids from multiple floral sources such as E. plantagineum and Heliotropium europaeum. In addition, retail samples of blended honeys (with no labeling to suggest that pyrrolizidine alkaloid-producing floral sources were used in the blends) have been shown to contain up to approximately 250 ppb pyrrolizidine alkaloids. PMID:15479038

  20. Optimization of processing parameters for extraction of total alkaloids of Rhizoma corydalis in Rhizoma corydalis Dispensing Granules by using Box-Behnken experimental design%Box-Behnken响应面法优化延胡索配方颗粒的提取工艺

    Institute of Scientific and Technical Information of China (English)

    白璐; 贺文娟; 崔春利; 王梅; 郭东艳; 宋忠兴; 唐志书

    2013-01-01

    Objective To optimize the processing parameters and apply for the extraction of the total alkaloids of Rhizoma corydalis in Rhizoma corydalis Dispensing Granules. Method Based on the results of single-factor-a-time-technique, a response surface methodology was employed, with the extraction duration,the ratio of water to sample,the extraction times as the independent variables. The response variable was the extraction rate of total alkaloids of Rhizoma corydalis. Result According to regression equation to determine,the best extraction conditions for the extraction duration were as follows:100 min,thc ratio of water to sample 12. 5: 1 (mL · g-1 ) , extraction three times. Conclusion Under the process conditions, the total alkaloids extraction rate of Rhizoma corydalis is 1. 94% , which was in consistency with the theoretic value and had some practical value.%目的 优选延胡索配方颗粒中延胡索总生物碱提取的工艺条件.方法 采用单因素实验结合Box-Behnken响应面法,以延胡索总生物碱提取率为评价指标进行实验,考察提取时间、水料比和提取次数3个因素对提取工艺的影响.结果 根据回归方程确定的最佳提取工艺条件为:提取时间100 min;水料比12.5∶1 (mL·g-1);提取次数3次.结论 采用该工艺条件,延胡索总生物碱的提取率为1.94%,与理论值预测值接近,具有一定的实用价值.

  1. Alkaloids from Galanthus nivalis.

    Science.gov (United States)

    Berkov, Strahil; Codina, Carles; Viladomat, Francesc; Bastida, Jaume

    2007-07-01

    Phytochemical studies on Galanthus nivalis of Bulgarian origin resulted in the isolation of five compounds: 11-O-(3'-hydroxybutanoyl)hamayne, 3,11-O-(3',3''-dihydroxybutanoyl)hamayne, 3-O-(2''-butenoyl)-11-O-(3'-hydroxybutanoyl)hamayne, 3,11,3''-O-(3',3'',3'''-trihydroxybutanoyl)hamayne, and 2-O-(3'-acetoxybutanoyl)lycorine, together with five known alkaloids: ungeremine, lycorine, tazettine, hamayne, and ismine. Their structures were determined by (1)H and (13)C NMR spectroscopy and two-dimensional (1)H-(1)H and (1)H-(13)C chemical shift correlation experiments.

  2. Combining the [2,3] Sigmatropic Rearrangement and Ring-Closing Metathesis Strategies for the Synthesis of Spirocyclic Alkaloids. A Short and Efficient Route to (+/-)-Perhydrohistrionicotoxin

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Hagberg, Lars; Poulsen, Anders

    1999-01-01

    This paper describes the use of selenium-based [2,3] sigmatropic rearrangement in combination with ruthenium-catalyzed ring-closing metathesis (RCM) for the synthesis of azaspiro ring systems, as exemplified by the reactions of model substrates 5 and 6. The methodology has been applied to a short...

  3. Total synthesis, structural, and biological evaluation of stylissatin A and related analogs.

    Science.gov (United States)

    Shaheen, Farzana; Jabeen, Almas; Ashraf, Samreen; Nadeem-Ul-Haque, Muhammad; Shah, Zafar Ali; Ziaee, Muhammad Asad; Dastagir, Nida; Ganesan, A

    2016-09-01

    The natural product cyclic peptide stylissatin A (1a) was reported to inhibit nitric oxide production in LPS-stimulated murine macrophage RAW 264.7 cells. In the current study, solid-phase total synthesis of stylissatin A was performed by using a safety-catch linker and yielded the peptide with a trans-Phe(7) -Pro(6) linkage, whereas the natural product is the cis rotamer at this position as evidenced by a marked difference in NMR chemical shifts. In order to preclude the possibility of 1b being an epimer of the natural product, we repeated the synthesis using d-allo-Ile in place of l-Ile and a different site for macrocyclization. The resulting product (d-allo-Ile(2) )-stylissatin A (1c) was also found to have the trans-Phe(7) -Pro(6) peptide conformations like rotamer 1b. Applying the second route to the synthesis of stylissatin A itself, we obtained stylissatin A natural rotamer 1a accompanied by rotamer 1b as the major product. Rotamers 1a, 1b, and the epimer 1c were separable by HPLC, and 1a was found to match the natural product in structure and biological activity. Six related analogs 2-7 of stylissatin A were synthesized on Wang resin and characterized by spectral analysis. The natural product (1a), the rotamer (1b), and (d-allo-Ile(2) )-stylissatin A (1c) exhibited significant inhibition of NO(.) . Further investigations were focused on 1b, which also inhibited proliferation of T-cells and inflammatory cytokine IL-2 production. The analogs 2-7 weakly inhibited NO(.) production, but strongly inhibited IL-2 cytokine production compared with synthetic peptide 1b. All analogs inhibited the proliferation of T-cells, with analog 7 having the strongest effect. In the analogs, the Pro(6) residue was replaced by Glu/Ala, and the SAR indicates that the nature of this residue plays a role in the biological function of these peptides. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27526945

  4. Effects of total alkaloid of sophora alopecuroids on bladder detrusor muscle activity in diabetic cystopathy rats%苦豆子总碱对糖尿病性膀胱病大鼠逼尿肌活动的影响

    Institute of Scientific and Technical Information of China (English)

    李妍; 孙安; 牛彩琴

    2016-01-01

    Objective To observe the influence of the total alkaloid of sophora alopecuroids L (TASa) on bladder detru-sor muscle activity in diabetic cystopathy(DCP) rats. Methods (1)The diabetic rat model was established by adopting strepto-zotocin(STZ);(2)the urodynamic indicators were detected for establishing the DCP model;(3)the constant temperature perfusion bath tank was adopted to divide the isolated bladder detrusor muscle strips into the control group (normal muscle strip,12 samples) and DCP model group(DCP muscle strip,72 samples),then,the DCP group was subdivided into the TASa group,TASa combined verapamil group,TASa combined phentolamine group,TASa combined indometacin group and TASa combined with atropine group,12 samples in each group. The influence of TASa on the spontaneous contraction of DCP detrusor muscle was investigated. Results TASa could increase the contraction amplitude of bladder detrusor musclen with dose-effect dependence(r=0.89,t=3.39, P0.05). Verapamil could significantly inhibit the TASa action for contracting bladder detrusor mus-cle,but atropine,phetolamine,benzhydramine and indomethacin had no influence. Conclusion TASa may activate calcium ion channel to increase contraction of bladder detrusor muscle.%目的:观察苦豆子总碱(TASa)对糖尿病性膀胱病(DCP)大鼠膀胱逼尿肌活动的影响。方法(1)采用链脲佐菌素法建造糖尿病模型;(2)测定尿流动力学指标确立DCP模型;(3)采用恒温灌流浴槽,将大鼠膀胱逼尿肌离体肌条标本分为对照组(正常肌条,12份)和DCP模型组(DCP肌条,72份),再将DCP模型组分为TASa组、TASa联合异搏定(维拉帕米)组、TASa联合酚妥拉明组、TASa联合苯海拉明组、TASa联合消炎痛(吲哚美辛)组和TASa联合阿托品组,各12份。探讨TASa对DCP逼尿肌自发收缩的影响。结果 TASa能增强DCP膀胱逼尿肌自发收缩的振幅,并具有量效依赖性(r=0.89,t=3.39

  5. Prescription and technology of nux vomica total alkaloids sustained-release tablets%马钱子总生物碱缓释片处方和工艺的研究

    Institute of Scientific and Technical Information of China (English)

    管庆霞; 封文静; 李永吉; 王录娜; 李伟男

    2013-01-01

    Hydroxypropyl methyl cellulose ( HPMC ) as skeleton material was prepared for nux vomica alkaloids sustained-release tablets. This paper established HPLC method for detecting nux vomica alkaloids sustained release tablets and investigated its release rate in vitro. The factors affected release rate also was explored. The results showed that specification and amount of HPMC had significant effect on the release rate, and nux vomica alkaloids sustained release tablets conformed to Higuchi equation. Compared with ordinary tablets, the new tablets had significantly sustained release effect. This method had advantages in preparation, expense appearance of tablets.%以羟丙基甲基纤维素(HPMC)为骨架材料,制备马钱子生物碱缓释片,建立马钱子生物碱缓释片释放度的HPLC测定方法,并考察其体外释放度.采用HPLC测定马钱子生物碱缓释片的体外释放度,并对影响释药的因素进行了单因素考察.羟丙甲纤维素(HPMC)的规格和用量对释药速率有显著影响,马钱子生物碱缓释片的体外释放曲线基本符合Higuchi方程.本法制备的缓释片比普通片具有明显的缓释作用.该制备工艺简单易行,生产成本低,片剂外观及可压性良好.

  6. Concise synthetic approaches to naturally occurring β-hydroxyphenylarsonic: first total synthesis of papanerine, its derivative, and praecansone B

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xue; Lee, Yong Rok [Yeungnam Univ., Gyeongsan (Korea, Republic of); Kim, Sung Hong [Korea Basic Science Institute, Daegu (Korea, Republic of)

    2012-04-15

    The total synthesis of biologically interesting β-hydroxyphenylarsonic, papanerine (1), its derivative 2, praecansone B (3), and pongapinone A (4) has been accomplished starting from commercially available 2,4-dihydroxyacetophenone or 6-methoxy-2,4-dihydroxyacetophenone in 3 steps by a convergent strategy through ben zopyran formations, O-methylation, and coupling reactions.

  7. Total synthesis and structural confirmation of the marine natural product Dysinosin A: a novel inhibitor of thrombin and Factor VIIa.

    Science.gov (United States)

    Hanessian, Stephen; Margarita, Roberto; Hall, Adrian; Johnstone, Shawn; Tremblay, Martin; Parlanti, Luca

    2002-11-13

    The structure and absolute configuration of the marine antithrombotic product dysinosin A was confirmed by total synthesis. The strategy involved disconnections to three subunits, of which two were synthesized from the readily available l-glutamic acid, d-leucine, and d-mannitol. The Grubbs olefin metathesis carbocyclization reaction was utilized to prepare two intermediates. PMID:12418860

  8. A new isochroman-4-one derivative from the peel of Musa sapientum L. and its total synthesis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new isochroman-4-one, 7,8-dihydroxy-3-methylisochroman-4-one was isolated from water soluble fraction of Musa sapientum L. Its structure was determined by spectroscopic evidences and its total synthesis has also been reported. The compound showed potent antihypertensive activity.

  9. Biosynthesis of tylophora alkaloids

    International Nuclear Information System (INIS)

    Using labelled precursors, biosynthesis of the tylophora alkaloids, tylophorine, tylophorinidine and tylophorinide has been investigated in Tylophora asthmatica plants. The radioactive precursors, phenylalanine-2-14C, benzoic acid-1-14C, benzoic acid-ring 14C, acetate-2-14C, ornithine-5-14C, acetate-2-14C, ornithine-5-14C and cinnamic acid-2-14C were administered to the plants individually by wick technique. Tylophorine was isolated in each case and assayed for its radioactivity to find out the incorporation of the label into it. The results indicate that: (1) phenylalanine via cinnamic acid is an important precursor in the biosynthesis of tylophorine (2) orinithine participates in tylophorine biosynthesis via pyrroline and (3) tylophorinidine may be a direct precursor of tylophorine. (M.G.B.)

  10. Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

    OpenAIRE

    Thilo Focken; Stephen Hanessian

    2014-01-01

    A review of the synthesis of natural products and bioactive compounds adopting phosphonamide anion technology is presented highlighting the utility of phosphonamide reagents in stereocontrolled bond-forming reactions. Methodologies utilizing phosphonamide anions in asymmetric alkylations, Michael additions, olefinations, and cyclopropanations will be summarized, as well as an overview of the synthesis of the employed phosphonamide reagents.

  11. Toxicity of Total Alkaloid from Tripterygium wilfordii Hook against Mythimna separata (Walker)and Its Effects of on AChE and Ach%雷公藤总生物碱对粘虫幼虫的毒力及对乙酰胆碱酯酶和乙酰胆碱的影响

    Institute of Scientific and Technical Information of China (English)

    周琳

    2011-01-01

    雷公藤生物碱是雷公藤Tripterygium wilfordii Hook中的主要杀虫活性物质.为进一步阐明雷公藤总生物碱的杀虫活性及杀虫作用机理提供线索和依据,研究采用载毒叶片法测定了雷公藤总生物碱对粘虫(Mythimna separata (Walker))三龄幼虫的胃毒毒力,观察了粘虫五龄幼虫的中毒症状,并测定了其对不同中毒阶段粘虫五龄幼虫头部乙酰胆碱酯酶(AChE)活性和乙酰胆碱(ACh)含量的影响.结果表明,雷公藤总生物碱对粘虫三龄幼虫48,72,96,120 h的胃毒LC50分别为306.39,216.12,157.18,129.92 mg/L;试虫中毒后行动迟缓,停止取食,继而软瘫麻痹(即麻醉),后复苏(或死亡),复苏试虫可再次取食、麻醉、复苏(或死亡),如此反复,直止死亡;雷公藤总生物碱对各中毒期试虫AChE无明显的抑制或激活作用;麻醉期试虫体内ACh的相对含量与同期对照无显著差异,复苏期有所下降.%Alkaloid is the main insecticidal composition in Tripterygium wilfordii Hook,a famous insecticidal plant. In order to study its insecticidal activites and mechanism ,the stomach toxicity of the total alkaloid against larvae of Mythimna separata Walker was tested, their toxicity symptoms were observed, and its effects on the activities of AChE and the content of ACh of larval heads in different toxicity stages were assayed. The results showed the stomach toxicity LD50 values of the total alkaloid against the 3rd instar larvae of M. separata in 24,48,96 and 120 h post treatment were 306.39,216.12,157.18 and 129. 92 mg/L. In vivo toxicity symptoms were characterized by a definite sequence of events, starting with moving slowly,stopping feeding, flaccid paralysis and recovering or death. Anabiotic insects started feeding ,were paralyzed, recovered or died again and up to death. It was presumed the total alkaloid from T. wilfordii influenced the nerve system of insects. AChE was not strongly inhibited or activated by the total alkaloid

  12. Concise Asymmetric Construction of C2 -symmetric 1,9-Diarylnonanoids Using a Hypervalent Silicon Complex: Total Synthesis of (-)-Ericanone.

    Science.gov (United States)

    Kotani, Shunsuke; Kai, Kosuke; Shimoda, Yasushi; Hu, Hao; Gao, Shen; Sugiura, Masaharu; Ogasawara, Masamichi; Nakajima, Makoto

    2016-02-01

    By using a phosphine oxide-catalyzed enantioselective double aldol reaction, we achieved the concise construction of C2 -symmetric 1,9-diarylnonanoids, enabling the synthesis of (-)-ericanone from p-hydroxybenzaldehyde in 6 steps with 65 % overall yield. The enantioselective double aldol reaction is useful for establishing C2 -symmetric 1,9-diaryl-3,7-dihydroxy-5-nonanones with a single operation. Furthermore, the use of o-nosyl-protected p-hydroxybenzaldehyde and a 4,4'-disubstituted BINAP dioxide catalyst dramatically improved the reactivity and selectivity in the double aldol reaction, enabling the total synthesis of (-)-ericanone with high yield and with excellent enantiopurity.

  13. Total synthesis of the α-subunit of human glycoprotein hormones: toward fully synthetic homogeneous human follicle-stimulating hormone.

    Science.gov (United States)

    Aussedat, Baptiste; Fasching, Bernhard; Johnston, Eric; Sane, Neeraj; Nagorny, Pavel; Danishefsky, Samuel J

    2012-02-22

    Described herein is the first total chemical synthesis of the unique α-subunit of the human glycoprotein hormone (α-hGPH). Unlike the biologically derived glycoprotein hormones, which are isolated as highly complex mixtures of glycoforms, α-hGPH obtained by chemical synthesis contains discrete homogeneous glycoforms. Two such systems have been prepared. One contains the disaccharide chitobiose at the natural N-glycosylation sites. The other contains dodecamer oligosaccharides at these same sites. The dodecamer sugar is a consensus sequence incorporating the key features associated with human glycoproteins.

  14. An Improved Method of Total Synthesis of 2-Methoxypodocarpane-8,11,13-triene

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    12-Methoxypodocarpane-8,11,13-triene 1, the key intermediate in the synthesis of some important diterpenes, was synthesized in an efficient way, which has the characteristics of short route, simple operation and high yield.

  15. Total Synthesis of Clavosolide A via Tandem Allylic Oxidation/Oxa-Conjugate Addition Reaction

    Science.gov (United States)

    Baker, Joseph B.; Kim, Hyoungsu; Hong, Jiyong

    2015-01-01

    The tandem allylic oxidation/oxa-conjugate addition reaction promoted by the gem-disubstituent effect in conjunction with the NHC-mediated oxidative esterification was explored for the facile synthesis of clavosolide A. PMID:26236051

  16. Structural Basis for β-Carboline Alkaloid Production by the Microbial Homodimeric Enzyme McbB.

    Science.gov (United States)

    Mori, Takahiro; Hoshino, Shotaro; Sahashi, Shusaku; Wakimoto, Toshiyuki; Matsui, Takashi; Morita, Hiroyuki; Abe, Ikuro

    2015-07-23

    The β-carboline (βC) alkaloids occur throughout nature and exhibit diverse biological activities. In contrast to βC alkaloid synthesis in plants, the biosynthesis in microorganisms remains poorly understood. The recently reported McbB from Marinactinospora thermotolerans is a novel enzyme proposed to catalyze the Pictet-Spengler (PS) reaction of L-tryptophan and oxaloacetaldehyde to produce the βC scaffold of marinacarbolines. In this study, we solved the crystal structure of McbB complexed with L-tryptophan at 2.48 Å resolution, which revealed the novel protein folding of McbB and the totally different structure from those of other PS condensation catalyzing enzymes, such as strictosidine synthase and norcoclaurine synthase from plants. Structural analysis and site-directed mutagenesis confirmed that the previously proposed catalytic Glu97 at the active-site center functions as an acid and base catalyst. Remarkably, the structure-based mutants R72A and H87A, with expanded active-site cavities, newly accepted bulky phenylglyoxal as the aldehyde substrate, to produce 1-benzoyl-3-carboxy-β-carboline. PMID:26120001

  17. Total Synthesis of ( - )-Kaerophyllin, ( - )-Hinokinin and (±)-Iso-hinokinin

    Institute of Scientific and Technical Information of China (English)

    夏亚穆; 梁其任; 王小龙; 曹小平; 潘鑫复

    2003-01-01

    A convenient and rapid approach for the syntheses of (-)-kaerophyllin (1), (-)-hinokinin (2) and (±)-isohinokinin (3) was described. The key steps were involved in condensation of aromatic aldehyde and alkylation of the resulting ester to give the complete skeleton of dibenzylbutyrolactone-lignan. Hydrolysis, followed by resolution with quinine, reduction and when appropriate, oxidation gave the title compound. The asynunetric total synthesis of the kaerophyllin (1) was reported for the first tlme.

  18. 1,6-asymmetric induction in boron-mediated aldol reactions: application to a practical total synthesis of (+)-discodermolide.

    Science.gov (United States)

    Paterson, Ian; Delgado, Oscar; Florence, Gordon J; Lyothier, Isabelle; Scott, Jeremy P; Sereinig, Natascha

    2003-01-01

    By relying solely on substrate-based stereocontrol, a practical total synthesis of the microtubule-stabilizing anticancer agent (+)-discodermolide has been realized. This exploits a novel aldol bond construction with 1,6-stereoinduction from the boron enolate of (Z)-enone 3 in addition to aldehyde 2. The 1,3-diol 7 is employed as a common building block for the C(1)-C(5), C(9)-C(16), and C(17)-C(24) subunits. [reaction--see text

  19. Total Chemical Synthesis,Assembly of Human Torque Teno Virus Genome

    Institute of Scientific and Technical Information of China (English)

    Zheng Hou; Gengfu Xiao

    2011-01-01

    Torque teno virus(TTV)is a nonenveloped virus containing a single-stranded,circular DNA genome of approximately 3.8kb.We completely synthesized the 3808 nucleotides of the TTV(SANBAN isolate)genome,which contains a hairpin structure and a GC-rich region.More than 100 overlapping oligonucleotides were chemically synthesized and assembled by polymerise chain assembly reaction(PCA),and the synthesis was completed with splicing by overlap extension(SOEing).This study establishes the methodological basis of the chemical synthesis of a viral genome for use as a live attenuated vaccine or gene therapy vector.

  20. Survey of Iranian Plants For Saponins Alkaloids Flavonoids And Tannins. IV

    OpenAIRE

    M.H. Salehi Surmaghi; Y. Aynehchi GH. Amin; Z. Mahmoodi

    1992-01-01

    A total of 149 plant extracts representing 49 different families has been screened for saponins, flavonoids, tannins and alkalodids. positive tests obtained were 145 (97) for saponins 74 (50%) for alkaloids 16 (51%) for fiavonoisds and 60 (40%) for tannins.

  1. Effect of Total Alkaloids from Solanum lyratum on Regulating Apoptosis and Cell Cycle of A549 Cells Through VEGF-related Pathway%白英总碱通过VEGF相关信号通路调控A549细胞的凋亡与周期

    Institute of Scientific and Technical Information of China (English)

    韩林; 孙彩霞; 王建农

    2016-01-01

    目的:基于血管内皮生长因子(VEGF)相关信号通路探讨白英总碱对A549细胞的凋亡与周期的影响。方法设立对照组和白英总碱低、中、高剂量组(50,100,200 mg·L-1),通过流式细胞术检测细胞凋亡及周期分布情况, Western blot法检测PI3K、 Akt、 Ras、 MAP2、 VEGF蛋白的表达。结果流式细胞术检测白英总碱将该细胞周期阻滞于G2期,呈现剂量依赖性的诱导A549细胞的凋亡,尤其是早期凋亡细胞。 Western blot结果显示,白英总碱均可下调PI3K、 Akt、 Ras、 MAP2、 VEGF蛋白的表达,中、高剂量组各蛋白的相对表达量与对照组比较,差异均有统计学意义(P<0.01)。结论白英总碱可通过调控VEGF相关信号通路诱导A549细胞的凋亡,阻滞细胞周期于G2期。%ObjectiveTo investigate the effect of total alkaloids fromSolanumlyratumon the apoptosis and cell cycle of A549 cells based on vascular endothelial growth factor(VEGF)-related signal pathway.MethodsControl group and three experimental groups were set up,cell cycle and apoptosis were tested by flow cytometry,and protein levels of PI3K,Akt,Ras,MAP2,and VEGF were examined by Western blot method.ResultsThe results of flow cytometry showed that total alkaloids fromSolanumlyratumarrested the cell cycle at G2 phase,and induced A549 cells apoptosis in a dose-dependent manner,especially for the early apoptotic cells. The results of Western blotting showed that total alkaloids fromSolanumlyratumdown-regulated the protein levels of PI3K,Akt,Ras,MAP2,and VEGF,and the relative protein expression quantity in middle- and high-dose groups obviously differed from that of the control group (P<0.01).ConclusionTotal alkaloids fromSolanumlyratumcould induce A549 cells apoptosis and arrest cell cycle at G2/M phase through VEGF-related signal pathway.

  2. Antimicrobial activity of benzylisoquinoline alkaloids.

    Science.gov (United States)

    Villar, A; Mares, M; Rios, J L; Canton, E; Gobernado, M

    1987-04-01

    The antimicrobial in vitro activity of 14 benzylisoquinoline alkaloids was investigated by agar diffusion and agar dilution methods against several genera of microorganisms that included Streptococcus, Staphylococcus, Bacillus, Lysteria, Escherichia, Salmonella, Klebsiella, Pseudomonas, Enterobacter, Serratia, Shigella, Mycobacterium and Candida. Anolobine was the most active compound against grampositive bacteria with MIC90 between 12 and 50 mg/l; less active were anonaine, lysicamine and liriodenine. All the alkaloids of the noraporphine and oxoaporphine groups, with the exception of isopiline, showed activity against Mycobacterium phlei (MIC 6-25 mg/l). Candida albicans ATCC26555 was inhibited by anonaine, nornantenine and xylopine (MIC 3-12 mg/l). None of the alkaloids tested had a significant activity against gramnegative rods. The action against susceptible microorganisms was bactericidal. PMID:3615557

  3. Alkaloids from Stems of Ervatamia yunnanensis (Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    Shuang LIANG; Xin Gen LUO; Hai Sheng CHEN; Xiao Dong ZHANG; Mao HUANG; Wen Yong LIU

    2006-01-01

    Six indole alkaloids were isolated from the stems of Ervatamia yunnanensis. Among them, 10-hydroxy-19, 20-dihydroisositsirikine (Ⅰ) is new. The other five are known alkaloids,namely: matrine (Ⅱ), 19, 20-dihydroisositsuikine (Ⅲ), 19-s-voacangarine (Ⅳ), 11'-methoxyl- 19s-heyneanine (Ⅴ), conodurine (Ⅵ). The structural elucidation of the alkaloids was based on spectral means.

  4. Alkaloids from stems of Ervatamia yunnanensis

    Institute of Scientific and Technical Information of China (English)

    Xin Gen Luo; Hai Sheng Chen; Shuang Liang; Mao Huang; Wei Dong Xuan; Li Jin

    2007-01-01

    Six indole alkaloids were isolated from the stems of Ervatamia yunnanensis.Among them, yunnanensine (Ⅰ) is new.The other five are known alkaloids, namely: 19,20-E-vallesamine (Ⅱ), 19s-heyneanine (Ⅲ), ibogaine (Ⅳ), ibogamine (Ⅴ), coronaridine (Ⅵ).The structural elucidation of the alkaloids was based on spectral means.

  5. FIVE NEW NORDITERPENOID ALKALOIDS FROM ACONITUM SINOMONTANUM

    Institute of Scientific and Technical Information of China (English)

    FENG-PENG WANG; CHONG-SHENG PENG; XI-XIAN JIAN; DONG-LIN CHEN

    2001-01-01

    From the roots of A conitum sinomontanum, five new norditerpenoid alkaloids, sinomontanitines A (1) and B (2), sinomontanines A (3), B (4) and C (5), were isolated together with the known alkaloids lappaconitine (6) and ranaconitine (7), The structures of the new alkaloids were determined by spectral analysis.

  6. Total Synthesis and Structure-Activity Relationship of Glycoglycerolipids from Marine Organisms

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2014-06-01

    Full Text Available Glycoglycerolipids occur widely in natural products, especially in the marine species. Glycoglycerolipids have been shown to possess a variety of bioactivities. This paper will review the different methodologies and strategies for the synthesis of biological glycoglycerolipids and their analogs for bioactivity assay. In addition, the bioactivities and structure-activity relationship of the glycoglycerolipids are also briefly outlined.

  7. Total synthesis of desoxycyclomarin C and the cyclomarazines A and B.

    Science.gov (United States)

    Barbie, Philipp; Kazmaier, Uli

    2016-07-01

    Removing the β-hydroxy group from the prenylated tryptophan moiety of cyclomarins simplifies the synthesis of these interesting natural products significantly, without having a noteworthy effect on the anti-tuberculosis activity of the cyclomarins. In contrast, cyclomarazines did not show biological activity. PMID:27241664

  8. Biosynthesis and Total Synthesis Studies on The Jadomycin Family of Natural Products

    OpenAIRE

    Sharif, Ehesan U.; O’Doherty, George A.

    2012-01-01

    Jadomycins are unique angucycline polyketides, which are produced by soil bacteria Streptomyces venezuelae under specific nutrient and environmental conditions. Their unique structural complexity and biological activities have engendered extensive study of the jadomycin class of natural compounds in terms of biological activity, biosynthesis, and synthesis.

  9. Total Synthesis of the Antimicrotubule Agent (+)-Discodermolide Using Boron-Mediated Aldol Reactions of Chiral Ketones.

    Science.gov (United States)

    Paterson; Florence; Gerlach; Scott

    2000-01-01

    With a similar mechanism of action to taxol, the title compound 1 is a particularly promising candidate for development in cancer chemotherapy. This efficient synthesis, based on stereocontrolled aldol reactions, should help to overcome the scarce natural supply of 1 from the rare sponge source.

  10. I. Cyclopeptide alkaloids; II. Phycocyanobilipeptides

    Energy Technology Data Exchange (ETDEWEB)

    Lagarias, J.C.

    1979-09-01

    Several examples of the 14-membered, para-bridged ring system of the cyclopeptide alkaloids have been synthesized via an active ester cyclization. The yield of monomeric cyclopeptide varied from 1 to 33% and was affected by the amino acid substitution pattern and amide conformation of the linear peptide precursors. Both the synthetic models and a naturally cyclopeptide alkaloid, ceanothine B, bind monovalent (Li/sup +/) and divalent (Ca/sup + +/, Mg/sup + +/) cations. Seven cyclopeptide alkaloids, phencyclopeptines 1-7, have been found distributed among three forms of the shrub Ceanothus integerrimus. Chemical degradation, mass spectroscopy, and /sup 1/H NMR spectroscopy have established structures for these seven compounds, three of which have been previously reported. The utility of cyclopeptide alkaloid structure and the distribution for chemotaxonomic assignments is discussed. Field desorption mass spectroscopy has identified five phencyclopeptines in the crude alkaloidal extracts of Ceanothus sanguineus. A new paired-ion HPLC system for the separation of these alkaloids is discussed. Amino acid analysis, electron impact mass spectroscopy, and /sup 1/H NMR spectroscopy have established the structures of six phencyclopeptines including two isomeric compounds 5 and 6. The structure of 2 has not been previously reported. The smallest cyanogen bromide fragment derived from the ..beta..-subunit of Synechococcus sp 6301 C-phycocyanin, the blue heptapeptide 2, has been investigated by 360 MHz /sup 1/H NMR spectroscopy. The peptide portion, heptapeptide 3, was synthesized independently and used in comparative spectroscopic analysis.These studies have led to complete assignment of the structure of the peptide-linked phycocyanobilin and elucidation of the nature of the thioether chromophore-peptide linkage.

  11. The distribution of inole alkaloids in different organs of Catharanthus roseus G. Don. (Vinca rosea L

    Directory of Open Access Journals (Sweden)

    Hassan Ebrahimzadeh

    1996-08-01

    Full Text Available The study of alkaloid extract of the leaf of Vinca rosea by TLC showed the existence of 13 bands, 7 bands of them were: Serpentine, Vincristine, Vinblastine, Ajmaline, Catharantine, Vindoline and Ajmalicine. The existence of these 7 alkaloids was confirmed in the young leaves, old leaves and the roots of the plant by HPLC. Furthermore, two alkaloids with the short retention times and one alkaloid with the medium retention time in the young leaf, three alkaloids with the short retention time and one alkaloid with long retention time in the old leaf, and one alkaioid with the short retention time and two other alkaloids with the long retention times in the root, were observed."nThe study of absorption spectrum of alkaloid extract and its comparison with absorption spectrum of ajmalicine showed that the latter can be used for drawing a standard curve and detecting the amount of total alkaloids. The total alkaloids in fresh root, old leaf and young leaf were 2.1 mg , 1.3 mg and 0.9 mg/g respectively, Vindoline and Catharantine were major alkaloids in all of them. However, their amount were more in the root (1.2 mg/ g of fresh material, 0.85 in the old leaf and 0.38 in the young leaf. Vinblastine existed in all three samples but its amount was more in the root {0.22 mg per gramme of the fresh material in the root, 0.26 in the young leaf and 0.003 in the old leaf."nAjmalicine was detected only in the leaf and its amount was more in young leaf than the old leaf (0.141 mg/g of the fresh material in the young leaf and 0.013 in the old leaf. Serpentine was seen in all of the studied organs but its amount was more in the young leaf than other organs (0.192 mg/ g of the fresh material in the young leaf, 0.11 in the root and 0.07 in the old leaf. Ajmaline existed in all of the organs in minute amount but in the old leaf was more (0 .07 mg/g of the fresh material in the old !eaf,0.044 in the young leaf and 0.04 in the root . The percentage of unknown

  12. ISOLATION AND PURIFICATION OF ALKALOIDS FROM PLUMULA NELUMBINIS BY DOUBLE-COLUMN ADSORPTION CHROMOTOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jixiang; GUO Jinsheng; OU Lailiang

    2007-01-01

    The performance of adsorption and separation for liensinine, isoliensinine and neferine was studied by double-column adsorption chromatography using macroporous adsorption and cation exchange resins. The alkaloid extract with 49.2% total contents by mass representing 10.6% liensinine, 10.6% isoliensinine and 28.0% neferine respectively was prepared by D72 cation exchange resins, in which most of the impurities were water-soluble alkaloids. Furthermore, the alkaloid extract with 82.6% total contents by mass containing 33.1%, 15.0% and 34.5% of the three adsorbates respectively was prepared by double-column adsorption chromatography using AKS-W macroporous adsorption and D72 cation exchange resins. As a result, the content of single and total alkaloids has been greatly increased by the double-column adsorption chromatography.

  13. ISOLATION AND PURIFICATION OF ALKALOIDS FROM PLUMULA NELUMBINIS BY DOUBLE-COLUMN ADSORPTION CHROMOTOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The performance of adsorption and separation for liensinine, isoliensinine and neferine was studied by double-column adsorption chromatography using macroporous adsorption and cation exchange resins. The alkaloid extract with 49.2% total contents by mass representing 10.6% liensinine, 10.6% isoliensinine and 28.0% neferine respectively was prepared by D72 cation exchange resins, in which most of the impurities were water-soluble alkaloids. Furthermore,the alkaloid extract with 82.6% total contents by mass containing 33.1%, 15.0% and 34.5% of the three adsorbates respectively was prepared by double-column adsorption chromatography using AKS-W macroporous adsorption and D72 cation exchange resins. As a result, the content of single and total alkaloids has been greatly increased by the double-column adsorption chromatography.

  14. Total Synthesis of Two 4, 5-Dioxo-seco-eudesmane Sesquiterpenes

    Institute of Scientific and Technical Information of China (English)

    Li Jing FANG; Chen Xi ZHANG; Jin Chun CHEN; Guo Jun ZHENG; Yu Lin LI

    2005-01-01

    A facile synthetic route to two seco-eudesmane, 4, 5-dioxo-10-epi-4, 5-seco-γeudesmane (1) and 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmol (2) from (+)-dihydrocarvone has been described. Avoiding expensive reagents, this highly economic method especially suits for the synthesis of 4, 5-seco-eudesman-type and ophianon-type sesquiterpenes with a double bond at position 11 and 12.

  15. The Efficient and Enantiospecific Total Synthesis of Cyclopenta[b]phenanthrenes Structurally-related to Neurosteroids

    OpenAIRE

    Qian, Mingxing; Covey, Douglas F.

    2010-01-01

    We report an efficient synthesis of cyclopenta[b]phenanthrenes functionalized at C-3 and C-8 from an optically pure Hajos-Parrish ketone. The key step is a neutral alumina catalyzed Michael addition of a Hajos-Parrish ketone derivative (4) to 1,7-octadien-3-one (2) in 98% yield. This Michael addition product went through Krapcho decarbomethoxylation, aldol condensation, lithium liquid ammonia reduction, Wacker oxidation and acid catalyzed cyclization to form cyclopenta[b]phenanthrene (1a) in ...

  16. Total synthesis of the aristolochic acids, their major metabolites, and related compounds.

    Science.gov (United States)

    Attaluri, Sivaprasad; Iden, Charles R; Bonala, Radha R; Johnson, Francis

    2014-07-21

    Plants from the Aristolochia genus have been recommended for the treatment of a variety of human ailments since the time of Hippocrates. However, many species produce the highly toxic aristolochic acids (AAs), which are both nephrotoxic and carcinogenic. For the purposes of extensive biological studies, a versatile approach to the synthesis of the AAs and their major metabolites was devised based primarily on a Suzuki-Miyaura coupling reaction. The key to success lies in the preparation of a common ring-A precursor, namely, the tetrahydropyranyl ether of 2-nitromethyl-3-iodo-4,5-methylendioxybenzyl alcohol (27), which was generated in excellent yield by oxidation of the aldoxime precursor 26. Suzuki-Miyaura coupling of 27 with a variety of benzaldehyde 2-boronates was accompanied by an aldol condensation/elimination reaction to give the desired phenanthrene intermediate directly. Deprotection of the benzyl alcohol followed by two sequential oxidation steps gave the desired phenanthrene nitrocarboxylic acids. This approach was used to synthesize AAs I-IV and several other related compounds, including AA I and AA II bearing an aminopropyloxy group at position-6, which were required for further conversion to fluorescent biological probes. Further successful application of the Suzuki-Miyaura coupling reaction to the synthesis of the N-hydroxyaristolactams of AA I and AA II then allowed the synthesis of the putative, but until now elusive, N-acetoxy- and N-sulfonyloxy-aristolactam metabolites. PMID:24877584

  17. Lycopodium alkaloids from Palhinhaea cernua

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Fu-Wei [Graduate University of Chinese Academy of Sciences, Beijing (China); Luo, Ji-Feng; Wang, Yue-Hu, E-mail: wangyuehu@mail.kib.ac.cn [Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences (China); Sun, Qian-Yun; Yang, Fu-Mei [Key Laboratory of Chemistry for Natural Products, Guizhou Province and Chinese Academy of Sciences (China); Liu, Fang [College of Landscape and Horticulture, Yunnan Agricultural University (China); Long, Chun-Lin, E-mail: long@mail.kib.ac.cn [College of Life and Environmental Sciences, Minzu University of China, Beijing, (China)

    2012-07-01

    Two new Lycopodium alkaloids, acetyllycoposerramine M and palcernine A were isolated from whole plant extracts of Palhinhaea cernua L. together with ten previously identified compounds. The structures of the new compounds were elucidated by spectroscopic methods and single-crystal X-ray diffraction analyses using the Flack parameter. (author)

  18. Quaternary alkaloids of tinospora species.

    Science.gov (United States)

    Bisset, N G; Nwaiwu, J

    1983-08-01

    The occurrence of quaternary alkaloids in TINOSPORA (and PARABAENA) species (Menispermaceae) has been studied. The main components were generally the protoberberine bases berberine and palmatine, with jatrorrhizine an occasional minor constituent, and the aporphine base magnoflorine. Choline was also often present. Only magnoflorine was detected in the PARABAENA material examined. PMID:17404996

  19. Influence of the Total Gas Flow at Different Reaction Times for CVD-Graphene Synthesis on Polycrystalline Nickel

    Directory of Open Access Journals (Sweden)

    M. P. Lavin-Lopez

    2016-01-01

    Full Text Available Optimization of the total gas flow (CH4+H2 during the reaction step for different reaction times for CVD-graphene synthesis on polycrystalline nickel foil using an atmospheric pressure set-up is reported. A thickness value related to number of graphene layers in each of the synthesized samples was determined using an Excel-VBA application. This method assigned a thickness value between 1 and 1000 and provided information on the percentage of each type of graphene (monolayer, bilayer, and multilayer deposited onto the polycrystalline nickel sheet. The influence of the total gas flow during the reaction step and the reaction time was studied in detail. Optical microscopy showed that samples were covered with different types of graphene, such as multilayer, few-layer, bilayer, and monolayer graphene. The synthesis variables were optimized according to the thickness value and the results were verified by Raman spectroscopy. The best conditions were obtained with a reaction temperature of 980°C, a CH4/H2 flow rate ratio of 0.07 v/v, a reaction time of 1 minute, and a total gas flow of 80 NmL/min. In the sample obtained under the optimized conditions, 80% of the area was covered with monolayer graphene and less than 1% with multilayer graphene.

  20. GC-MS investigation of Amaryllidaceae alkaloids in Galanthus xvalentinei nothosubsp. subplicatus.

    Science.gov (United States)

    Sarikaya, Buket Bozkurt; Berkov, Strahil; Bastida, Jaume; Kaya, Gulen Irem; Onur, Mustafa Ali; Somer, Nehir Unver

    2013-03-01

    A GC-MS analysis of alkaloids in the aerial parts and bulbs of Galanthus xvalentinei nothosubsp. subplicatus was performed for the first time. Totally, twenty-six alkaloids were identified, of which tazettine and galanthindole were the major ones. Acetylcholinesterase inhibitory activity of the alkaloidal extracts was determined using modified in vitro Ellman's method. Significant anticholinesterase activity was observed in the tested samples (bulbs: IC50 = 21.3 microg/mL, aerial parts: IC50 = 16.3 microg/mL).

  1. Influence of Some Heavy Metals on Growth, Alkaloid Content and Composition in Catharanthus roseus L.

    Science.gov (United States)

    Srivastava, N. K.; Srivastava, A. K.

    2010-01-01

    Shoot biomass production, alkaloid content and composition as influence by cadmium, manganese, nickel and lead at uniform dose of 5 mM were investigated in Catharanthus roseus plants grown in sand culture. Treatment with Mn, Ni, and Pb significantly enhanced total root alkaloid accumulation. Cd and Ni treatment resulted in two-fold where as Pb treatment resulted in three fold increase in serpentine content of roots. The non-significant affect on biomass suggests that plants can withstand metal stress at the level tested with positive affect on root alkaloid content. PMID:21969751

  2. An analysis of Sorghum halepense’s behavior in presence of tropane alkaloids from Datura stramonium extracts

    Directory of Open Access Journals (Sweden)

    Butnariu Monica

    2012-07-01

    Full Text Available Abstract Background This study aimed to quantify the allelopathic potential of Datura stramonium (Jimson weed. Sorghum halepense (Johnsongrass tolerance was assessed by germinating, seed and growing seedlings, dosing of photo-synthesis pigments, followed by treatment with D. stramonium extract tropane alkaloids. Results Preliminary chemical analysis of the extracts showed the presence of alkaloids. The presence of alkaloids was confirmed through HPLC–UV system analysis. Various concentrations of analytic purity alkaloids had similar effects on germination and development of S. halepense’s root systems with those of extracts from of D. stramonium. Germination was not affected by any of the tested extracts, but growth was inhibited by the presence of tropane alkaloids. Extracts had effects at higher alkaloid concentrations. Seedlings of S. halepense developed toxicity symptoms in the presence of alkaloid extracts, but the occurrence of several chlorotic and necrotic areas was noticed in the flower extract biotest. Conclusions Results show that the tested species is sensitive to alkaloids in their growth environment. This research justifies the fact that aqueous extracts from D. stramonium are adequate to the situations in which S. halepense becomes damaging.

  3. An analysis of Sorghum halepense’s behavior in presence of tropane alkaloids from Datura stramonium extracts

    Science.gov (United States)

    2012-01-01

    Background This study aimed to quantify the allelopathic potential of Datura stramonium (Jimson weed). Sorghum halepense (Johnsongrass) tolerance was assessed by germinating, seed and growing seedlings, dosing of photo-synthesis pigments, followed by treatment with D. stramonium extract tropane alkaloids. Results Preliminary chemical analysis of the extracts showed the presence of alkaloids. The presence of alkaloids was confirmed through HPLC–UV system analysis. Various concentrations of analytic purity alkaloids had similar effects on germination and development of S. halepense’s root systems with those of extracts from of D. stramonium. Germination was not affected by any of the tested extracts, but growth was inhibited by the presence of tropane alkaloids. Extracts had effects at higher alkaloid concentrations. Seedlings of S. halepense developed toxicity symptoms in the presence of alkaloid extracts, but the occurrence of several chlorotic and necrotic areas was noticed in the flower extract biotest. Conclusions Results show that the tested species is sensitive to alkaloids in their growth environment. This research justifies the fact that aqueous extracts from D. stramonium are adequate to the situations in which S. halepense becomes damaging. PMID:22839364

  4. Total Synthesis of Plakilactones C, B and des-Hydroxyplakilactone B by the Oxidative Cleavage of Gracilioether Furanylidenes.

    Science.gov (United States)

    Norris, Matthew D; Perkins, Michael V

    2016-08-01

    A chemoselective oxidative cleavage of synthetic gracilioether B, 11-epi-gracilioether C benzoate, and des-hydroxygracilioether C with pyridinium chlorochromate, which proceeds with loss of the furanyl acetate, has enabled total synthesis and stereochemical elucidation of the marine sponge metabolites (4R,6R)-plakilactone C, (4R,6R,9R)-plakilactone B, and (4R,6R)-des-hydroxyplakilactone B. des-Hydroxygracilioether C, the putative biosynthetic precursor to hippolachnin A, was also found to undergo a facile ene cyclization on treatment with SnCl4. PMID:27359169

  5. Reactivity umpolung in intramolecular ring closure of 3,4-disubstituted butenolides: diastereoselective total synthesis of paeonilide.

    Science.gov (United States)

    Deore, Prashant S; Argade, Narshinha P

    2013-11-15

    Remarkable reactivity reversal stratagem in 3,4-disubstituted butenolides under acidic conditions is described. Design of a suitably substituted multifunctional butenolide followed by an acid-catalyzed chemo- and diastereoselective intramolecular ring closure via the reactivity umpolung has been demonstrated to accomplish a concise total synthesis of paeonilide. Overall, the present protocol involves one-pot reduction of an α,β-unsaturated carbon-carbon double bond and intramolecular nucleophilic insertion of oxygen function at the electron-rich γ-position of butenolide. The involved mechanistic aspects have also been discussed. PMID:24175675

  6. Tanjungides A and B: New Antitumoral Bromoindole Derived Compounds from Diazona cf formosa. Isolation and Total Synthesis

    Directory of Open Access Journals (Sweden)

    Carmen Murcia

    2014-02-01

    Full Text Available Tanjungides A (1 (Z isomer and B (2 (E isomer, two novel dibrominated indole enamides, have been isolated from the tunicate Diazona cf formosa. Their structures were determined by spectroscopic methods including HRMS, and extensive 1D and 2D NMR. The stereochemistry of the cyclised cystine present in both compounds was determined by Marfey’s analysis after chemical degradation and hydrolysis. We also report the first total synthesis of these compounds using methyl 1H-indole-3-carboxylate as starting material and a linear sequence of 11 chemical steps. Tanjungides A and B exhibit significant cytotoxicity against human tumor cell lines.

  7. Tanjungides A and B: new antitumoral bromoindole derived compounds from Diazona cf formosa. isolation and total synthesis.

    Science.gov (United States)

    Murcia, Carmen; Coello, Laura; Fernández, Rogelio; Martín, María Jesús; Reyes, Fernando; Francesch, Andrés; Munt, Simon; Cuevas, Carmen

    2014-02-21

    Tanjungides A (1) (Z isomer) and B (2) (E isomer), two novel dibrominated indole enamides, have been isolated from the tunicate Diazona cf formosa. Their structures were determined by spectroscopic methods including HRMS, and extensive 1D and 2D NMR. The stereochemistry of the cyclised cystine present in both compounds was determined by Marfey's analysis after chemical degradation and hydrolysis. We also report the first total synthesis of these compounds using methyl 1H-indole-3-carboxylate as starting material and a linear sequence of 11 chemical steps. Tanjungides A and B exhibit significant cytotoxicity against human tumor cell lines.

  8. The first protein ever synthesized in vitro——a personal reminiscence of the total synthesis of crystalline insulin

    Institute of Scientific and Technical Information of China (English)

    ZHANG YouShang

    2010-01-01

    @@ The total synthesis of crystalline bovine insulin started in 1958 was fully accomplished in 1965.This formidable task was a collaboration of the Institute of Biochemistry in Shanghai, the Institute of Organic Chemistry in Shanghai and the Department of Chemistry in Beijing University.It is difficult to say exactly how many people were involved in this project, as many contributors, e.g.Director Wang YingLai and Deputy Director Cao TianQin of the Institute of Biochemistry, were not included in the author list of the published papers.

  9. Enantioselective total synthesis of (−)-epoxyquinols A and B. Novel, convenient access to chiral epoxyquinone building blocks through enzymatic desymmetrization

    OpenAIRE

    Mehta, Goverdhan; Islam, Kabirul

    2004-01-01

    Following our recent total synthesis of the biologically potent natural products epoxyquinols A and B in racemic form, we have now accomplished the total synthesis of the (−)-epoxyquinols A and B, anti-podes of the angiogenesis inhibiting natural products, through a protocol that involves enzymatic desymmetrization of a versatile epoxyquinone derivative, readily available from the Diels–Alder adduct of cyclopentadiene and p-benzoquinone.

  10. Studies of Genetic Variation of Essential Oil and Alkaloid Content in Boldo (Peumus boldus).

    Science.gov (United States)

    Vogel, H; Razmilic, I; Muñoz, M; Doll, U; Martin, J S

    1999-02-01

    Boldo is a tree or shrub with medicinal properties native to Chile. The leaves contain alkaloids and essential oils. Variation of total alkaloid concentration, of the alkaloid boldine, and essential oil components were studied in different populations from northern, central, and southern parts of its geographic range and in their progenies (half-sib families). Total alkaloid concentration showed genetic variation between progenies of the central population but not between populations. Boldine content found in concentrations of 0.007 to 0.009% did not differ significantly between populations. Principal components of the essential oil were determined genetically, with highest values for ascaridole in the population of the north and for P-cymene in the south. Between half-sib families genetic variation was found in the central and northern populations for these components. The high heritability coefficients found indicate considerable potential for successful selection of individuals for these characters. PMID:17260243

  11. The First Total Synthesis of 4,4′-Biisofraxidin

    Institute of Scientific and Technical Information of China (English)

    LEi,Jiang-Guang(雷建光); LIN,Gu-Qiang(林国强)

    2002-01-01

    The 4,4′- biisofraxidin, isolated from balsamina L. was synthesized for the first time in the total yield of 7% by 11 steps, in which the key step was the cyclization and Ni(0)- catalyzed coupling reaction.

  12. Binary stress induces an increase in indole alkaloid biosynthesis in Catharanthus roseus.

    Science.gov (United States)

    Zhu, Wei; Yang, Bingxian; Komatsu, Setsuko; Lu, Xiaoping; Li, Ximin; Tian, Jingkui

    2015-01-01

    Catharanthus roseus is an important medicinal plant, which produces a variety of indole alkaloids of significant pharmaceutical relevance. In the present study, we aimed to investigate the potential stress-induced increase of indole alkaloid biosynthesis in C. roseus using proteomic technique. The contents of the detectable alkaloids ajmalicine, vindoline, catharanthine, and strictosidine in C. roseus were significantly increased under binary stress. Proteomic analysis revealed that the abundance of proteins related to tricarboxylic acid cycle and cell wall was largely increased; while, that of proteins related to tetrapyrrole synthesis and photosynthesis was decreased. Of note, 10-hydroxygeraniol oxidoreductase, which is involved in the biosynthesis of indole alkaloid was two-fold more abundant in treated group compared to the control. In addition, mRNA expression levels of genes involved in the indole alkaloid biosynthetic pathway indicated an up-regulation in their transcription in C. roseus under UV-B irradiation. These results suggest that binary stress might negatively affect the process of photosynthesis in C. roseus. In addition, the induction of alkaloid biosynthesis appears to be responsive to binary stress. PMID:26284098

  13. Binary Stress Induces an Increase in Indole Alkaloid Biosynthesis in Catharanthus roseus

    Directory of Open Access Journals (Sweden)

    Wei eZhu

    2015-07-01

    Full Text Available Catharanthus roseus is an important medicinal plant, which produces a variety of indole alkaloids of significant pharmaceutical relevance. In the present study, we aimed to investigate the potential stress-induced increase of indole alkaloid biosynthesis in C. roseus using proteomic technique. The contents of the detectable alkaloids ajmalicine, vindoline, catharanthine, and strictosidine in C. roseus were significantly increased under binary stress. Proteomic analysis revealed that the abundance of proteins related to tricarboxylic acid cycle and cell wall was largely increased; while, that of proteins related to tetrapyrrole synthesis and photosynthesis was decreased. Of note, 10-hydroxygeraniol oxidoreductase, which is involved in the biosynthesis of indole alkaloid was two-fold more abundant in treated group compared to that in control. In addition, mRNA expression levels of genes involved in the indole alkaloid biosynthetic pathway indicated an up-regulation in their transcription in C. roseus under UV-B irradiation. These results suggest that binary stress might negatively affect the process of photosynthesis in C. roseus. In addition, the induction of alkaloid biosynthesis appears to be responsive to binary stress.

  14. Aporphine and tetrahydroprotoberberine alkaloids from the leaves of Guatteria friesiana (Annonaceae) and their cytotoxic activities

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Emmanoel Vilaca; Cruz, Pedro Ernesto O. da, E-mail: emmanoelvc@gmail.com [Universidade Federal de Sergipe (UFSE), Sao Cristovao, SE (Brazil). Departamento de Quimica; Marques, Francisco A.; Barison, Andersson; Maia, Beatriz Helena L.N.S. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Centro Politecnico. Departamento de Quimica; Pinheiro, Maria Lucia B. [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Departamento de Quimica; Ruiz, Ana Lucia T.G.; Marchetti, Gabriela M.; Carvalho, Joao Ernesto de [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Centro Pluridisciplinar de Pesquisas Quimicas, Biologicas e Agricolas. Divisao de Farmacologia e Toxicologia

    2013-05-15

    Phytochemical investigation of the leaves of Guatteria friesiana (Annonaceae) afforded three new isoquinoline alkaloids, 13-hydroxy-discretinine, 6,6a-dehydroguatteriopsiscine and 9-dehydroxy-1-methoxy-dihydroguattouregidine. Eight known alkaloids were also isolated, 13-hydroxy-2,3,9,10-tetramethoxyprotoberberine, guatteriopsiscine, lysicamine, liriodenine, atherospermidine, lanuginosine, 7,8-dihydro-8-hydroxypalmatine and palmatine. 13-Hydroxy- 2,3,9,10-tetramethoxyprotoberberine was only obtained by synthesis and is being reported as a natural product for the first time. The structures of the isolated alkaloids were established by extensive analysis of 1D and 2D nuclear magnetic resonance (NMR) and mass spectrometric (MS) data, as well as by comparison with data reported in the literature. The in vitro cytotoxic activity of the major alkaloids was evaluated against tumor and non-tumor cell lines. All of the alkaloids evaluated were determined to be inactive based on National Cancer Institute (NCI/USA) criteria. However, the alkaloid palmatine exhibited a cytostatic effect on MCF-7 (breast) and U251 (glioma) human tumor cell lines, with GI{sub 50} values lower than 20.0 Greek-Small-Letter-Mu mol L{sup -}1 (10.5and 16.2 Greek-Small-Letter-Mu molL{sup -1}, respectively), suggesting a selective cytotoxic action (author)

  15. Total synthesis and biochemical evaluation of azumamides A–E and analogs

    DEFF Research Database (Denmark)

    Villadsen, Jesper

    structures. The key step in this route is a diastereoselective Mannich reaction, which enabled us to prepare two site-specifically edited epimeric azumamide analogs, where the stereochemistry in the unique -amino acid was inverted. The two epimeric homologs were screened together with azumamide A−E against...... the entire panel of recombinant HDAC isoforms. Thus, providing the first full profiling of the azumamides. The epimers were inactive against the full panel of HDAC enzymes and show that the -amino acid scaffold is highly sensitive to modifications in the stereochemistry. The profiling of the natural products...... analogs. Having observed the importance of the aromatic amino acid in the azumamides, a tryptophan-series was also prepared. The synthesis of these compounds underline the broad perspective and flexibility of the developed Mannich strategy. The dimethylated analogs were found to be poor HDAC inhibitors...

  16. Heronapyrrole D: A case of co-inspiration of natural product biosynthesis, total synthesis and biodiscovery

    Directory of Open Access Journals (Sweden)

    Jens Schmidt

    2014-05-01

    Full Text Available The heronapyrroles A–C have first been isolated from a marine-derived Streptomyces sp. (CMB-0423 in 2010. Structurally, these natural products feature an unusual nitropyrrole system to which a partially oxidized farnesyl chain is attached. The varying degree of oxidation of the sesquiterpenyl subunit in heronapyrroles A–C provoked the hypothesis that there might exist other hitherto unidentified metabolites. On biosynthetic grounds a mono-tetrahydrofuran-diol named heronapyrrole D appeared a possible candidate. We here describe a short asymmetric synthesis of heronapyrrole D, its detection in cultivations of CMB-0423 and finally the evaluation of its antibacterial activity. We thus demonstrate that biosynthetic considerations and the joint effort of synthetic and natural product chemists can result in the identification of new members of a rare class of natural products.

  17. Isolation and Characterization of Antineoplastic Alkaloids from Catharanthus Roseus L. Don. Cultivated in Egypt

    OpenAIRE

    Shams, Khaled A; Nazif, Naglaa M; Abdel Azim, Nahla S; Abdel Shafeek, Khaled A; El-Missiry, Mostafa M.; Ismail, Shams I; Seif El Nasr, Medhat M

    2009-01-01

    Vinblastine and vincristine (the antileukemic agents) were isolated, in a pure form, from Catharanthus roseus L. Don., cultivated in Egypt, by several chromatographic techniques. Five modified methods for the preparation of total alkaloids were carried out. All the isolated mixtures were evaluated by HPLC and HPTLC analyses. The antineoplastic alkaloids; vinblastine and vincristine, were isolated by the use of vacuum liquid chromatographic column on silica gel : aluminium oxide (1:1) mixed be...

  18. Influence of Some Heavy Metals on Growth, Alkaloid Content and Composition in Catharanthus roseus L.

    OpenAIRE

    Srivastava, N. K.; A.K. Srivastava

    2010-01-01

    Shoot biomass production, alkaloid content and composition as influence by cadmium, manganese, nickel and lead at uniform dose of 5 mM were investigated in Catharanthus roseus plants grown in sand culture. Treatment with Mn, Ni, and Pb significantly enhanced total root alkaloid accumulation. Cd and Ni treatment resulted in two-fold where as Pb treatment resulted in three fold increase in serpentine content of roots. The non-significant affect on biomass suggests that plants can withstand meta...

  19. Alcalóides alquilpiridínicos de esponjas marinhas Alkylpyridine alkaloids from marine sponges

    Directory of Open Access Journals (Sweden)

    Adaíla M. P. Almeida

    1997-04-01

    Full Text Available The chemistry of alkylpyridine alkaloids originating from marine sponges is comprehensively reviewed, with emphasis on their natural occurrence, methods for their isolation, spectroscopic characterization, biological activities e chemical synthesis. A likely chemotaxonomic role is suggested, as markers for sponges of the Order Haplosclerida (Demospongiae.

  20. Total synthesis of cordatanine, structural reassignment of drymaritin, and anti-inflammatory activity of synthetic precursors.

    Science.gov (United States)

    Fang, Hsin Wei; Liao, Yu-Ren; Hwang, Tsong-Long; Shieh, Po-Chuen; Lee, Kuo-Hsiung; Hung, Hsin-Yi; Wu, Tian-Shung

    2015-09-15

    In this study, cordatanine, with a canthin-6-one skeleton, was totally synthesized in four steps via a Pictet-Spengler reaction using tryptamine and methyl glyoxylate with a total yield of 8%. The NMR spectra of synthesized cordatanine compared well with those of drymaritin isolated by Hsieh et al., confirming the need to revise the original structural assignment. In addition, kumujian A, a synthetic intermediate, showed significant anti-inflammatory effects, inhibiting both superoxide anion generation (IC50 4.87 μg/mL) and elastase release (IC50 6.29 μg/mL). PMID:26248804

  1. Total Synthesis of Trimethoprim%甲氧苄啶的全合成

    Institute of Scientific and Technical Information of China (English)

    冀亚飞; 李前荣

    2001-01-01

    对甲酚为起始原料,以总收率40.6%的高收率合成了杀菌增效剂甲氧苄啶.对 甲酚进行溴化、水解反应得到4-羟基-3,5-二溴苯甲醛;该化合物以甲醇钠甲醇溶液 进行甲氧基化反应获得4-羟基-3,5-二甲氧基苯甲醛的酚钠盐,然后直接以硫酸二甲 酯进行甲基化反应得到3,4,5-三甲氧基苯甲醛;用其通过与甲醇钠、丙烯氰的甲醇溶 液反应得到肉桂氰衍生物;该衍生物先经碱催化的1,3-质子转移异构化到烯醚结构, 再与甲醇加成,直接与胍缩合环化,最终得到甲氧苄啶.%Antibacterial synergist trimethoprim was synthesized from p-cresol in an overall yield as high as 40. 6%. p-cresol was brominated and hydrolyzed to give 3, 5-dibromo-4-hydroxyben- zaldehyde, which was methoxylated by methanolic sodium methoxide associated with cuprous chloride and dimethyfformamide(DMF)as catalyst at 125℃ (ca. 0.SMPa)to provide sodium phenolate of 3,5- dimethoxy-4-hydroxybenzaldehyde, from which 3,4,5-trimethoxybenzaldehyde was obtained by methy lation directly with dimethylsuffate in aqueous sodium hydroxide. Efficient synthesis of trimethoprim from 3,4,5-trimethoxybenzaldehyde was accomplished by condensation with methanolic sodium methox ide, methanol and acrylonitrile via prior base-catalyzed 1,3-prototropic isomerization of cinnamonitrile converted into the enol ether, followed by addition with methanol at 90℃ (ca. 0.05MPa)and cyclo condensation directly with guanidine in dimethyl sulfoxide(DMSO)at 110℃ with the removal of methanol. "One-pot" method was used in the synthesis starting from economical, convenient and envi ronmental awareness.

  2. Monitoring the catalytic synthesis of glycerol carbonate by real-time attenuated total reflection FTIR spectroscopy

    NARCIS (Netherlands)

    Calvino-Casilda, V.; Mul, G.; Fernandez, J.F.; Rubio-Marcos, F.; Banares, M.A.

    2011-01-01

    In situ Attenuated Total Reflectance FTIR spectroscopy was used to study the carbonylation of glycerol with urea. Cobalt oxide nanoparticles, Co3O4, hierarchically dispersed on zinc oxide microparticles, ZnO, were used as catalysts. The present work demonstrates that in situ real-time attenuated tot

  3. Pyrrolizidine alkaloids of senecio sp from Peru

    Directory of Open Access Journals (Sweden)

    Liliana Ruiz Vásquez and Matías Reina Artiles

    2011-01-01

    Full Text Available Six pyrrolizidine alkaloids (PAs (two saturated macrocyclic, three unsaturated macrocyclic and one unsaturated seco-macrocyclic were isolated from native Peruvian Senecio species. The structures of these alkaloids were established by a complete NMR spectroscopic analysis, chemical transformations and comparison of their NMR data with those published for similar alkaloids. Three PAs were then tested for antifungal activity against Fusarium moniliforme, F. (Sheldon, F. oxysporum fs. lycopersici (Scheldt and F. solani (Mart, no significant activity being observed.

  4. Pyrrolizidine alkaloids of Senecio sp from Peru

    International Nuclear Information System (INIS)

    Six pyrrolizidine alkaloids (PAs) (two saturated macrocyclic, three unsaturated macrocyclic and one unsaturated seco-macrocyclic) were isolated from native Peruvian Senecio species. The structures of these alkaloids were established by a complete NMR spectroscopic analysis, chemical transformations and comparison of their NMR data with those published for similar alkaloids. Three PAs were then tested for antifungal activity against Fusarium moniliforme, F. (Sheldon), F. oxysporum fs. lycopersici (Scheldt) and F. solani (Mart), no significant activity being observed. (author)

  5. Pyrrolizidine alkaloids of Senecio sp from Peru

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Vasquez, Liliana; Reina Artiles, Matias [Instituto de Productos Naturales y Agrobiologia, CSIC, Tenerife (Spain); Gonzalez Coloma, Azucena [Instituto de Ciencias Agrarias (ICA), CSIC, Madrid (Spain); Cabrera Perez, Raimundo [Universidad de La Laguna (ULL), Tenerife (Spain). Unidad de Fitopatologia, Facultad de Biologia; Ruiz Mesia, Lastenia [Universidad Nacional de la Amazonia Peruana (LIPNAA-UNAP), AA.HH. Nuevo San Lorenzo, San Juan, Iquitos (Peru). Lab. de Investigacion en Productos Naturales Antiparasitarios de la Amazonia

    2011-07-01

    Six pyrrolizidine alkaloids (PAs) (two saturated macrocyclic, three unsaturated macrocyclic and one unsaturated seco-macrocyclic) were isolated from native Peruvian Senecio species. The structures of these alkaloids were established by a complete NMR spectroscopic analysis, chemical transformations and comparison of their NMR data with those published for similar alkaloids. Three PAs were then tested for antifungal activity against Fusarium moniliforme, F. (Sheldon), F. oxysporum fs. lycopersici (Scheldt) and F. solani (Mart), no significant activity being observed. (author)

  6. Sol–gel auto-combustion synthesis of totally immiscible NiAg alloy

    International Nuclear Information System (INIS)

    Highlights: ► Chemically synthesized immiscible NiAg alloy nanoparticles without protecting matrix. ► A chemical method providing both a nonequilibrium thermal process and a good mixing of precursors. ► Observation of extinction planes in NiAg alloy. -- Abstract: Immiscible crystalline NiAg alloy was successfully synthesized by the newly developed sol–gel auto-combustion method. The structure and composition were examined by X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM). All evidence supports that homogeneous NiAg alloy with FCC structure was synthesized. The differential thermal analysis and thermogravimetry (DTA–TG) measurement shows that the alloy has a good thermal stability until 315 °C. Unusually some extinction planes are observed in the XRD pattern and HRTEM images. The random distribution of atoms and the large difference between Ni and Ag atom form factors should be regarded as the main reasons for the observation of the extinction planes. The quenching like nonequilibrium thermal process in the combustion is taken as the key factor in the synthesis of immiscible alloy. And the addition of ethylene glycol in the precursors is found to benefit the formation of NiAg alloy.

  7. First Total Synthesis of Hyacinthacine A6 from the Protected Derivative of Polyhydroxylated Pyrrolidine

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tao-xiang; ZHOU Ling; AO Xiao-ping

    2008-01-01

    (1S,2R,3R,5R,7aR)-1,2-Dihydroxy-3-hydroxymethy1-5-methylpyrrolizidine(hyacinthacine A6,1) was synthesized by Wittig's methodology via the reaction of aldehyde 6,prepared from the partially protected derivative of polyhydroxylatcd pyrrolidine,with appropriated ylides,followed by cyclization through the internal reductive amination process of the resulting a,β-unsaturated ketone 7,and total deprotection.

  8. Synthesis,Charactcrization and Antibacterial Property of Strontium Half and Totally Substituted Hydroxyapatite Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    LIN Yingguang; YANG Zhuoru; CHENG Jiang; WANG Lianshi

    2008-01-01

    Nanoparticles of hydroxyapatite(HAP),strontium half substituted hydroxyapatite(SrCaHAP) and strontium totally substituted hydroxyapatite(SrHAP)were prepared by sol-gel-supercritical fluid drying (SCFD) method.The nanoparticles were characterized by element content analysis,FT-IR,XRD and TEM,and the effects of strontium substitution on crystal structure.crystallinity,particle shape and antibacterial propemes of the nanoparticles on Escherichia coli,Staphylococcus aureus,Lactobacillus were researched.Results show that strontium can half and totally substitute for calcium and enter the structure of apatite according to the initial atomic ratios of Sr/[Sr+Ca] as 0.5,1.The substitution decreases the IR wavenumbers of SrCaHAP and SrHAP, and changes the morphology of the nanoparticles from short rod shaped HAP to needle shaped SrCaHAE and back to short rod shaped SrHAP.The crystallinity of HAP is higher than that of SrCaHAP, but is lower thall that of SrHAP.Moreove~the antibacterial property of SrCaHAP and SrHAP are improved after the calcium is half and totally substituted by strontium.

  9. Efficient Total Chemical Synthesis of (13) C=(18) O Isotopomers of Human Insulin for Isotope-Edited FTIR.

    Science.gov (United States)

    Dhayalan, Balamurugan; Fitzpatrick, Ann; Mandal, Kalyaneswar; Whittaker, Jonathan; Weiss, Michael A; Tokmakoff, Andrei; Kent, Stephen B H

    2016-03-01

    Isotope-edited two-dimensional Fourier transform infrared spectroscopy (2 D FTIR) can potentially provide a unique probe of protein structure and dynamics. However, general methods for the site-specific incorporation of stable (13) C=(18) O labels into the polypeptide backbone of the protein molecule have not yet been established. Here we describe, as a prototype for the incorporation of specific arrays of isotope labels, the total chemical synthesis-via a key ester insulin intermediate-of 97 % enriched [(1-(13) C=(18) O)Phe(B24) ] human insulin: stable-isotope labeled at a single backbone amide carbonyl. The amino acid sequence as well as the positions of the disulfide bonds and the correctly folded structure were unambiguously confirmed by the X-ray crystal structure of the synthetic protein molecule. In vitro assays of the isotope labeled [(1-(13) C=(18) O)Phe(B24) ] human insulin showed that it had full insulin receptor binding activity. Linear and 2 D IR spectra revealed a distinct red-shifted amide I carbonyl band peak at 1595 cm(-1) resulting from the (1-(13) C=(18) O)Phe(B24) backbone label. This work illustrates the utility of chemical synthesis to enable the application of advanced physical methods for the elucidation of the molecular basis of protein function. PMID:26715336

  10. Extending the Glucosyl Ceramide Cassette Approach: Application in the Total Synthesis of Ganglioside GalNAc-GM1b

    Directory of Open Access Journals (Sweden)

    Miku Konishi

    2013-12-01

    Full Text Available The development of a novel cyclic glucosyl ceramide cassette acceptor for efficient glycolipid syntheses was investigated. p-Methoxybenzyl (PMB groups were selected as protecting groups at C2 and C3 of the glucose residue with the aim of improving the functionality of the cassette acceptor. The choice of the PMB group resulted in a loss of β-selectivity, which was corrected by using an appropriate tether to control the spatial arrangement and the nitrile solvent effect. To investigate the effect of linker structure on the β-selectivity of intramolecular glycosylation, several linkers for tethering the glucose and ceramide moiety were designed and prepared, namely, succinyl, glutaryl, dimethylmalonyl, and phthaloyl esters. The succinyl ester linker was the best for accessing the cassette form. The newly designed glucosyl ceramide cassette acceptor was then applied in the total synthesis of ganglioside GalNAc-GM1b.

  11. Isolation and Total Synthesis of Stolonines A-C, Unique Taurine Amides from the Australian Marine Tunicate Cnemidocarpa stolonifera.

    Science.gov (United States)

    Tran, Trong D; Pham, Ngoc B; Ekins, Merrick; Hooper, John N A; Quinn, Ronald J

    2015-07-01

    Cnemidocarpa stolonifera is an underexplored marine tunicate that only occurs on the tropical to subtropical East Coast of Australia, with only two pyridoacridine compounds reported previously. Qualitative analysis of the lead-like enhanced fractions of C. stolonifera by LC-MS dual electrospray ionization coupled with PDA and ELSD detectors led to the identification of three new natural products, stolonines A-C (1-3), belonging to the taurine amide structure class. Structures of the new compounds were determined by NMR and MS analyses and later verified by total synthesis. This is the first time that the conjugates of taurine with 3-indoleglyoxylic acid, quinoline-2-carboxylic acid and β-carboline-3-carboxylic acid present in stolonines A-C (1-3), respectively, have been reported. An immunofluorescence assay on PC3 cells indicated that compounds 1 and 3 increased cell size, induced mitochondrial texture elongation, and caused apoptosis in PC3 cells. PMID:26204949

  12. Isolation and Total Synthesis of Stolonines A-C, Unique Taurine Amides from the Australian Marine Tunicate Cnemidocarpa stolonifera.

    Science.gov (United States)

    Tran, Trong D; Pham, Ngoc B; Ekins, Merrick; Hooper, John N A; Quinn, Ronald J

    2015-07-22

    Cnemidocarpa stolonifera is an underexplored marine tunicate that only occurs on the tropical to subtropical East Coast of Australia, with only two pyridoacridine compounds reported previously. Qualitative analysis of the lead-like enhanced fractions of C. stolonifera by LC-MS dual electrospray ionization coupled with PDA and ELSD detectors led to the identification of three new natural products, stolonines A-C (1-3), belonging to the taurine amide structure class. Structures of the new compounds were determined by NMR and MS analyses and later verified by total synthesis. This is the first time that the conjugates of taurine with 3-indoleglyoxylic acid, quinoline-2-carboxylic acid and β-carboline-3-carboxylic acid present in stolonines A-C (1-3), respectively, have been reported. An immunofluorescence assay on PC3 cells indicated that compounds 1 and 3 increased cell size, induced mitochondrial texture elongation, and caused apoptosis in PC3 cells.

  13. Isolation and Total Synthesis of Stolonines A–C, Unique Taurine Amides from the Australian Marine Tunicate Cnemidocarpa stolonifera

    Directory of Open Access Journals (Sweden)

    Trong D. Tran

    2015-07-01

    Full Text Available Cnemidocarpa stolonifera is an underexplored marine tunicate that only occurs on the tropical to subtropical East Coast of Australia, with only two pyridoacridine compounds reported previously. Qualitative analysis of the lead-like enhanced fractions of C. stolonifera by LC-MS dual electrospray ionization coupled with PDA and ELSD detectors led to the identification of three new natural products, stolonines A–C (1–3, belonging to the taurine amide structure class. Structures of the new compounds were determined by NMR and MS analyses and later verified by total synthesis. This is the first time that the conjugates of taurine with 3-indoleglyoxylic acid, quinoline-2-carboxylic acid and β-carboline-3-carboxylic acid present in stolonines A–C (1–3, respectively, have been reported. An immunofluorescence assay on PC3 cells indicated that compounds 1 and 3 increased cell size, induced mitochondrial texture elongation, and caused apoptosis in PC3 cells.

  14. Total Synthesis of 4,5-Didehydroguadiscine: A Potent Melanogenesis Inhibitor from the Brazilian Medicinal Herb, Hornschuchia obliqua.

    Science.gov (United States)

    Tanabe, Genzoh; Sugano, Youta; Shirato, Miki; Sonoda, Naoki; Tsutsui, Nozomi; Morikawa, Toshio; Ninomiya, Kiyofumi; Yoshikawa, Masayuki; Muraoka, Osamu

    2015-07-24

    The first total synthesis of the 7,7-dimethylaporphinoid, 4,5-didehydroguadiscine (6), originally isolated from the stems and roots of Hornschuchia oblique (Annonaceae), was achieved by the condensation of homopiperonylamine (7) with an α,α-dimethylphenylacetic acid derivative (8) and subsequent Pschorr reaction of the resulting benzylisoquinoline intermediate (22). The reported (13)C NMR data were partially revised on the basis of the analysis of HMBC spectra measured under different conditions. The melanogenesis inhibitory activity (IC50 = 4.7 μM) of 6 was 40 times stronger than that of arbutin (174 μM), which was used as reference standard. Furthermore, 6 was the most potent natural melanogenesis inhibitor within this class of compounds. PMID:26135746

  15. Antimalarial activity of extracts and alkaloids isolated from six plants used in traditional medicine in Mali and Sao Tome.

    Science.gov (United States)

    Ancolio, C; Azas, N; Mahiou, V; Ollivier, E; Di Giorgio, C; Keita, A; Timon-David, P; Balansard, G

    2002-11-01

    Methanol and chloroform extracts were prepared from various parts of four plants collected in Mali: Guiera senegalensis (Gmel.) Combretaceae, Feretia apodanthera (Del.) Rubiaceae, Combretum micranthum (Don.) Combretaceae, Securidaca longepedunculata (Fres.) Polygalaceae and two plants -collected in Sao Tome: Pycnanthus angolensis (Welw.) Myristicaceae and Morinda citrifolia (Benth.) Rubiaceae were assessed for their in vitro antimalarial activity and their cytotoxic effects on human monocytes (THP1 cells) by flow cytometry. The methanol extract of leaves of Feretia apodanthera and the chloroform extract of roots of Guiera senegalensis exhibited a pronounced antimalarial activity. Two alkaloids isolated from the active extract of Guiera senegalensis, harman and tetrahydroharman, showed antimalarial activity (IC(50) lower than 4 microg/mL) and displayed low toxicity against THP1. Moreover, the decrease of THP1 cells in S phase of the cell cycle, after treatment with harman and tetrahydroharman, was probably due to an inhibition of total protein synthesis. PMID:12410545

  16. Total Synthesis of Purported Cephalosporolides H and I, Penisporolide B, and Their Stereoisomers.

    Science.gov (United States)

    Wang, Jian; Tong, Rongbiao

    2016-05-20

    Development of a unified, bioinspired synthetic strategy to access four possible diastereomers of unique 2,2-dimethyl-[5,5]-spiroacetal-cis-fused-γ-lactone (Me2SAFL) is reported, featuring pyridinium chlorochromate (PCC)-promoted oxidative ring expansion of β-hydroxy cyclic ethers and dehydrative ring-contraction rearrangement of 10-membered lactones. Synthetic utility of this strategy was demonstrated by total syntheses of 12 Me2SAFLs, corresponding to the purported cephalosporolide H (CesH), cephalosporolide I (CesI), and penisporolide B (PenB) and their possible diastereomers. Comprehensive NMR data analysis suggested that the tricyclic Me2SAFL core of CesH, CesI, and PenB should be revised to the same relative (3R*, 4R*, 6S*, 9R*) configuration and that the side chains required an unknown constitutional structure revision. PMID:27137949

  17. Total Observed Organic Carbon (TOOC): A Synthesis of North American Observations

    Science.gov (United States)

    Heald, C. L.; Goldstein, A. H.; Allan, J. D.; Aiken, A. C.; Apel, E.; Atlas, E. L.; Baker, A. K.; Bates, T. S.; Beyersdorf, A. J.; Blake, D. R.; Campos, T.; Coe, H.; Crounse, J. D.; DeCarlo, P. F.; de Gouw, J. A.; Dunlea, E. J.; Flocke, F. M.; Fried, A.; Goldan, P.; Griffin, R. J.; Herndon, S. C.; Holloway, J. S.; Holzinger, R.; Jimenez, J. L.; Junkermann, W.

    2007-01-01

    Measurements of organic carbon compounds in both the gas and particle phases made upwind, over and downwind of North America are synthesized to examine the total observed organic carbon (TOOC) in the atmosphere over this region. These include measurements made aboard the NOAA WP-3 and BAe-146 aircraft, the NOAA research vessel Ronald H. Brown, and at the Thompson Farm and Chebogue Point surface sites during the summer 2004 ICARTT campaign. Both winter and summer 2002 measurements during the Pittsburgh Air Quality Study are also included. Lastly, the spring 2002 observations at Trinidad Head, CA, surface measurements made in March 2006 in Mexico City and coincidentally aboard the C-130 aircraft during the MILAGRO campaign and later during the IMPEX campaign off the northwestern United States are incorporated. Concentrations of TOOC in these datasets span more than two orders of magnitude. The daytime mean TOOC ranges from 4.0 to 456 microg C/cubic m from the cleanest site (Trinidad Head) to the most polluted (Mexico City). Organic aerosol makes up 3-17% of this mean TOOC, with highest fractions reported over the northeastern United States, where organic aerosol can comprise up to 50% of TOOC. Carbon monoxide concentrations explain 46 to 86% of the variability in TOOC, with highest TOOC/CO slopes in regions with fresh anthropogenic influence, where we also expect the highest degree of mass closure for TOOC. Correlation with isoprene, formaldehyde, methyl vinyl ketone and methacrolein also indicates that biogenic activity contributes substantially to the variability of TOOC, yet these tracers of biogenic oxidation sources do not explain the variability in organic aerosol observed over North America. We highlight the critical need to develop measurement techniques to routinely detect total gas phase VOCs, and to deploy comprehensive suites of TOOC instruments in diverse environments to quantify the ambient evolution of organic carbon from source to sink.

  18. Total observed organic carbon (TOOC in the atmosphere: a synthesis of North American observations

    Directory of Open Access Journals (Sweden)

    C. L. Heald

    2008-04-01

    Full Text Available Measurements of organic carbon compounds in both the gas and particle phases made upwind, over and downwind of North America are synthesized to examine the total observed organic carbon (TOOC in the atmosphere over this region. These include measurements made aboard the NOAA WP-3 and BAe-146 aircraft, the NOAA research vessel Ronald H. Brown, and at the Thompson Farm and Chebogue Point surface sites during the summer 2004 ICARTT campaign. Both winter and summer 2002 measurements during the Pittsburgh Air Quality Study are also included. Lastly, the spring 2002 observations at Trinidad Head, CA, surface measurements made in March 2006 in Mexico City and coincidentally aboard the C-130 aircraft during the MILAGRO campaign and later during the IMPEX campaign off the northwestern United States are incorporated. Concentrations of TOOC in these datasets span more than two orders of magnitude. The daytime mean TOOC ranges from 4.0 to 456 μgC m−3 from the cleanest site (Trinidad Head to the most polluted (Mexico City. Organic aerosol makes up 3–17% of this mean TOOC, with highest fractions reported over the northeastern United States, where organic aerosol can comprise up to 50% of TOOC. Carbon monoxide concentrations explain 46 to 86% of the variability in TOOC, with highest TOOC/CO slopes in regions with fresh anthropogenic influence, where we also expect the highest degree of mass closure for TOOC. Correlation with isoprene, formaldehyde, methyl vinyl ketone and methacrolein also indicates that biogenic activity contributes substantially to the variability of TOOC, yet these tracers of biogenic oxidation sources do not explain the variability in organic aerosol observed over North America. We highlight the critical need to develop measurement techniques to routinely detect total gas phase VOCs, and to deploy comprehensive suites of TOOC instruments in diverse environments to quantify the ambient evolution of organic carbon from source

  19. Total Observed Organic Carbon (TOOC: A synthesis of North American observations

    Directory of Open Access Journals (Sweden)

    C. L. Heald

    2007-12-01

    Full Text Available Measurements of organic carbon compounds in both the gas and particle phases measured upwind, over and downwind of North America are synthesized to examine the total observed organic carbon (TOOC over this region. These include measurements made aboard the NOAA WP-3 and BAe-146 aircraft, the NOAA research vessel Ronald H. Brown, and at the Thompson Farm and Chebogue Point surface sites during the summer 2004 ICARTT campaign. Both winter and summer 2002 measurements during the Pittsburgh Air Quality Study are also included. Lastly, the spring 2002 observations at Trinidad Head, CA, surface measurements made in March 2006 in Mexico City and coincidentally aboard the C-130 aircraft during the MILAGRO campaign and later during the IMPEX campaign off the northwestern United States are incorporated. Concentrations of TOOC in these datasets span more than two orders of magnitude. The daytime mean TOOC ranges from 4.0 to 456 μgC m−3 from the cleanest site (Trinidad Head to the most polluted (Mexico City. Organic aerosol makes up 3–17% of this mean TOOC, with highest fractions reported over the northeastern United States, where organic aerosol can comprise up to 50% of TOOC. Carbon monoxide concentrations explain 46 to 86% of the variability in TOOC, with highest TOOC/CO slopes in regions with fresh anthropogenic influence, where we also expect the highest degree of mass closure for TOOC. Correlation with isoprene, formaldehyde, methyl vinyl ketene and methacrolein also indicates that biogenic activity contributes substantially to the variability of TOOC, yet these tracers of biogenic oxidation sources do not explain the variability in organic aerosol observed over North America. We highlight the critical need to develop measurement techniques to routinely detect total gas phase VOCs, and to deploy comprehensive suites of TOOC instruments in diverse environments to quantify the ambient evolution of organic carbon from source to sink.

  20. Intraspecific variability in the alkaloid metabolism of Galanthus elwesii.

    Science.gov (United States)

    Berkov, Strahil; Sidjimova, Borjana; Evstatieva, Luba; Popov, Simeon

    2004-03-01

    Alkaloid pattern of individuals from 16 Bulgarian Galanthus elwesii populations was investigated by GC/MS and TLC. Twenty-one Amaryllidaceae alkaloids were detected and 14 of them were identified. Crinane type alkaloids, haemanthamine or crinine, dominated alkaloid metabolism in most of the populations. With exception of one population, where the separate individuals showed variable alkaloid profiles (dominated by crinine or haemanthamine) the individuals of the rest of populations have identical and characteristic alkaloid profiles. Some populations showed remarkable differences in respect to their alkaloid pattern-type of biosynthesis, main alkaloids and number of alkaloids. Populations dominated by galanthamine type alkaloids were found as well. These data demonstrate that like the morphological features, the alkaloid metabolism of G. elwesii is also variable.

  1. Tropane alkaloids in food: poisoning incidents

    NARCIS (Netherlands)

    Adamse, P.; Egmond, van H.P.; Noordam, M.Y.; Mulder, P.P.J.; Nijs, de W.C.M.

    2014-01-01

    A large number of wild and cultured plants produce secondary metabolites that can be toxic to humans and animals. The present study aims to provide insight into the routes of (un)intentional poisonings of humans by tropane alkaloids. Poisonings of humans by tropane alkaloids occur as unintended inge

  2. Alkaloids from the Roots of Saccopetalum prolificum

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new alkaloid, named prolifine (1), was isolated along with four known alkaloids, liriodenine (2), 6-hydroxyonychine (3), isooncodine (4) and discretamine (5) from the roots of Saccopetalum prolificum. The structure of 1 was elucidated on the basis of spectroscopic and chemical methods.

  3. Alkaloids of some Asian Sedum species

    NARCIS (Netherlands)

    Kim, JH; THart, H; Stevens, JF

    1996-01-01

    The leafy parts of 16 Asian species belonging to the three sections of Sedum were investigated for the presence of alkaloids. Only in seven species of Sedum sect. Sedum were alkaloids found. Sedum bulbiferum, S. japonicum, S. lepidopodium, S. morrisomensis, S. oryzifolium, S. polytrichoides and S. s

  4. Multiple shoot cultures of Atropa belladonna: Effect of physico-chemical factors on growth and alkaloid formation

    International Nuclear Information System (INIS)

    Multiple shoot cultures were established from shoot tip and axillary meristem of the plant Atropa belladonna. The cultures were initially raised on agar medium and subsequently maintained on liquid medium of Murashige and Skoog (1962) supplemented with BA. These cultures were subjected to different doses of -y-irradiation. Recovery from the radiation effects was observed in tissues subjected to 29 Gy during four successive passages. Plant growth regulators influenced the growth and morphogenetic events of the tissues. The precursors of tropane alkaloids marginally increased the alkaloid synthesis during the stationary phase of growth. Shoot cultures, established from different field grown plants varying in alkaloid content, were morphologically similar and did not exhibit the parental characteristics with respect to alkaloid formation

  5. An integrated strategy for the systematic characterization and discovery of new indole alkaloids from Uncaria rhynchophylla by UHPLC/DAD/LTQ-Orbitrap-MS.

    Science.gov (United States)

    Pan, Huiqin; Yang, Wenzhi; Zhang, Yibei; Yang, Min; Feng, Ruihong; Wu, Wanying; Guo, Dean

    2015-08-01

    The exploration of new chemical entities from herbal medicines may provide candidates for the in silico screening of drug leads. However, this significant work is hindered by the presence of multiple classes of plant metabolites and many re-discovered structures. This study presents an integrated strategy that uses ultrahigh-performance liquid chromatography/linear ion-trap quadrupole/Orbitrap mass spectrometry (UHPLC/LTQ-Orbitrap-MS) coupled with in-house library data for the systematic characterization and discovery of new potentially bioactive molecules. Exploration of the indole alkaloids from Uncaria rhynchophylla (UR) is presented as a model study. Initially, the primary characterization of alkaloids was achieved using mass defect filtering and neutral loss filtering. Subsequently, phytochemical isolation obtained 14 alkaloid compounds as reference standards, including a new one identified as 16,17-dihydro-O-demethylhirsuteine by NMR analyses. The direct-infusion fragmentation behaviors of these isolated alkaloids were studied to provide diagnostic structural information facilitating the rapid differentiation and characterization of four different alkaloid subtypes. Ultimately, after combining the experimental results with a survey of an in-house library containing 129 alkaloids isolated from the Uncaria genus, a total of 92 alkaloids (60 free alkaloids and 32 alkaloid O-glycosides) were identified or tentatively characterized, 56 of which are potential new alkaloids for the Uncaria genus. Hydroxylation on ring A, broad variations in the C-15 side chain, new N-oxides, and numerous O-glycosides, represent the novel features of the newly discovered indole alkaloid structures. These results greatly expand our knowledge of UR chemistry and are useful for the computational screening of potentially bioactive molecules from indole alkaloids. Graphical Abstract A four-step integrated strategy for the systematic characterization and efficient discovery of new indole

  6. Genetic variation in alkaloid accumulation in leaves of Nicotiana

    Institute of Scientific and Technical Information of China (English)

    Bo SUN; Fen ZHANG; Guo-jun ZHOU; Guo-hai CHU; Fang-fang HUANG; Qiao-mei WANG; Li-feng JIN; Fu-cheng LIN; Jun YANG

    2013-01-01

    Alkaloids are plant secondary metabolites that are widely distributed in Nicotiana species and contribute greatly to the quality of tobacco leaves. Some alkaloids, such as nornicotine and myosmine, have adverse effects on human health. To reduce the content of harmful alkaloids in tobacco leaves through conventional breeding, a genetic study of the alkaloid variation among different genotypes is required. In this study, alkaloid profiles in leaves of five Nicotiana tabacum cultivars and Nicotiana tomentosiformis were investigated. Six alkaloids were identified from al six genotypes via gas chromatograph-mass spectrometry (GC-MS). Significant differences in alkaloid content were ob-served both among different leaf positions and among cultivars. The contents of nornicotine and myosmine were positively and significantly correlated (R2=0.881), and were also separated from those of other alkaloids by clustering. Thus, the genotype plays a major role in alkaloid accumulation, indicating a high potential for manipulation of alkaloid content through traditional breeding.

  7. Effect of total alkaloidal of tongbiling on cartilage and cellular metabolism in rats with collagen-induced arthritis%通痹灵总碱对胶原诱导型关节炎大鼠软骨及其细胞代谢的影响

    Institute of Scientific and Technical Information of China (English)

    陈纪藩; 赵诗哲; 陈光星; 刘清平; 陈宗良

    2005-01-01

    ,10,100,500,1 000μg/L)促进了软骨细胞蛋白多糖的降解(P<0.01),且呈量效关系.③不同浓度的通痹灵总碱(200,100,50,25 mg/L)及地塞米松可明显抑制软骨细胞蛋白多糖的降解(P<0.01)及一氧化氮的产生(P<0.01).结论:通痹灵总碱可抑制胶原诱导型关节炎大鼠趾关节软骨破坏;体外实验结果显示通痹灵总碱可对抗软骨细胞蛋白多糖的降解,其作用途径可能是通过抑制一氧化氮的生成来实现的.%BACKGROUND: Chinese medicine is rich in recognition and treatment for rheumatoid arthritis(RA) and has achieved attractable progression in researches of recent several years,characterized by variable therapeutic methods, definite therapeutic effects and few toxic side effects. Therefore, it is important scientifically and socially to further search for the effective drugs and methods for the treatment of RA in the field of Chinese medicine. There are few reports on whether Chinese herbs inhibit or block the destruction of cartilage and bone and promote their metabolism and repair for damage or not by variable approaches,targets and links in RA occurrence.OBJECTIVE: To probe into the mechanism of Chinese herbal tongbiling on cartilage destruction.DESIGN: Complete random design and control experimental study based on the experimental animals.SETTING: Golden Chamber teaching and research room of guangzhou university of traditional Chinese medicine.MATERIALS: The experiment was performed in Comprehensive Experimental Room of First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine from August 2002 to December 2003,in which,35female Wistar rats were employed,clean grade,weighted(110±20) g,provided by Animal Experimental Room of First Military Medical University of Chinese PLA, with qualified animal No. 2002A041.After 3 days adaptive breeding,Wistar rats were randomized into normal group,model group and total alkaloidal of tongbiling group(TBL group). TBL was extracted in

  8. Short-term toxicity studies of loline alkaloids in mice.

    Science.gov (United States)

    Finch, S C; Munday, J S; Munday, R; Kerby, J W F

    2016-08-01

    Epichloë endophytes have been used successfully in pastoral systems to reduce the impact of insect pests through the expression of secondary metabolites. The use of endophytes could be extended to other plant species, such as cereal crops, where the production of bioactive secondary metabolites would reduce the reliance on pesticides for insect control. The success of this approach is dependent on the selection of an appropriate secondary metabolite target which must not only be effective against insect pests but also be safe for grazing and monogastric animals. The loline alkaloids have been identified as possible target metabolites as they are associated with potent effects on insects and low toxicity to grazing animals. The purpose of the current study was to generate toxicological data on the loline alkaloids in a monogastric system using mice. Male and female mice were fed 415 mg/kg/day total lolines for a 3-week period. The loline treatment caused no statistically significant effect on gross pathology, histology, haematology, blood chemistry, heart rate, blood pressure or motor coordination. Reduced weight gain and food consumption were noted in the loline groups during the initial stages of the experiment. This experiment raises no food safety concerns for the loline alkaloids. PMID:27276360

  9. Bioactive acridone alkaloids from Swinglea glutinosa.

    Science.gov (United States)

    Weniger, B; Um, B H; Valentin, A; Estrada, A; Lobstein, A; Anton, R; Maillé, M; Sauvain, M

    2001-09-01

    A new prenylated acridone alkaloid, 1,3,5-trihydroxy-2,8-bis(3-methylbut-2-enyl)-10-methyl-9-acridone (1), was isolated from the stembark of Swinglea glutinosa, along with three known acridone alkaloids, 5-hydroxynoracronycine (2), 1,3,5-trihydroxy-4-methoxy-2-(3-methylbut-2-enyl)-10-methyl-9-acridone (3), and 1,3,5-trihydroxy-4-methoxy-10-methylacridone (4). The isolated alkaloids were assessed in vitro against chloroquine-sensitive and -resistant Plasmodium falciparum strains and for cytotoxicity using HeLa cells. PMID:11575960

  10. Norditerpenoid Alkaloids from Aconitum spicatum Stapf

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To search for pharmacologically and structurally interesting substances from traditional Chinese medicines,we investigated the chemical compounds of Aconitum spicatum Stapf. Two new norditerpenoid alkaloids,namely spicatine A (compound 1) and spicatine B (compound 2), as well as 11 known norditerpenoid alkaloids were isolated from the CHCl3 portion of the 90% ethanol extract of the roots of A. spicatum. The structures of the alkaloids were characterized on the basis of their spectral data, One of the isolated compounds showed significant cytotoxic activities (IC50 values < 200 μmol/L) against the HL-60 cell line.

  11. A second-generation total synthesis of (+)-discodermolide: the development of a practical route using solely substrate-based stereocontrol.

    Science.gov (United States)

    Paterson, Ian; Delgado, Oscar; Florence, Gordon J; Lyothier, Isabelle; O'Brien, Matthew; Scott, Jeremy P; Sereinig, Natascha

    2005-01-01

    A novel total synthesis of the complex polyketide (+)-discodermolide, a promising anticancer agent of sponge origin, has been completed in 7.8% overall yield over 24 linear steps, with 35 steps altogether. This second-generation approach was designed to rely solely on substrate control for introduction of the required stereochemistry, eliminating the use of all chiral reagents or auxiliaries. The common 1,2-anti-2,3-syn stereotriad found in each of three subunits, aldehyde 9 (C(1)-C(5)), ester 40 (C(9)-C(16)), and aldehyde 13 (C(17)-C(24)), was established via a boron-mediated aldol reaction of ethyl ketone 15 and formaldehyde, followed by hydroxyl-directed reduction to give 1,3-diol 14. Alternatively, a surrogate aldehyde 22 was employed for formaldehyde in this aldol reaction, leading to the beta-hydroxy aldehyde 20 as a common building block, corresponding to the discodermolide stereotriad. Key fragment unions were achieved by a lithium-mediated anti aldol reaction of ester 40 and aldehyde 13 under Felkin-Anh control to provide (16S,17S)-adduct 51 and a boron-mediated aldol reaction between enone 10 and aldehyde 9, exploiting unprecedented remote 1,6-stereoinduction, to give the (5S)-adduct 57.

  12. Enantioselective total synthesis of epoxyquinone natural products (−)-phyllostine, (+)-epoxydon, (+)-epiepoxydon and (−)-panepophenanthrin: access to versatile chiral building blocks through enzymatic kinetic resolution

    OpenAIRE

    Mehta, Goverdhan; Islam, Kabirul

    2004-01-01

    A new enzyme mediated protocol to access versatile chiral building blocks for the synthesis of epoxyquinone natural products is delineated. Total syntheses of (−)-phyllostine, (+)-epoxydon, (+)-epiepoxydon and (−)-panepophenanthrin have been accomplished to demonstrate the efficacy of this approach.

  13. Total synthesis of cis-hydroazulene sesquiterpenes. Base-induced and -directed elimination and rearrangement reactions of perhydronaphthalene-1,4-diol monosulfonate esters.

    NARCIS (Netherlands)

    Jenniskens, L.H.D.

    1992-01-01

    The total synthesis of a number of cis-fused hydroazulene sesquiterpenes is described in this thesis. In this synthetic study, ample attention is paid to the mechanistic aspects of the base- induced and -directed rearrangement and elimination reactions of perhydronaphthalene-1,4-diol monosulfonate e

  14. Studies on Preparation and Dissolution Test in vitro of Intragastric Floating Two-chamber Osmotic Pump Tablets of Total Alkaloids of Coptis chinensis and Evodia rutaecarpa%连萸总生物碱胃滞留双室渗透泵片的制备及体外释放度考察

    Institute of Scientific and Technical Information of China (English)

    方瑜; 史清文

    2011-01-01

    目的:对连萸总生物碱胃滞留双室渗透泵片(TCOPT)的制备方法进行研究,并考察其体外释放度.方法:以释放度为评价指标,采用正交设计实验优化处方与工艺.结果:最佳处方为:膨胀剂为PEO(Mw 5000000)与HPMC混合物(4∶1),用量50 mg,助推层渗透剂氯化钠用量为20 mg,包衣液致孔剂PEG 400用量10%.包衣增重9%.释药行为符合零级方程,具有明显的控释特征.结论:TCOPT具有良好的体外控释效果,可进一步进行体内释药行为考察.%Objective :To study prescription and technique of intragastric floating mo-chamber osmotic pump tablets (TCOPT)of total alkaloids of Coptis chinensis and Evodia rutaecarpa and inspect release property in vitro.Methods:The orthogonal experiment was designed to screen prescription and technique.Results :The optimization of prescription and technique were as follows:the expanding agent was a mixture of PEO and HPMC as a ratio of4:1 ;the osmotic agent in propelling layer contained sodium chloride 20 mg, PEG 400 in the cellulose acetate, 10% ;coating membrane in core tablet,9%.The release behavior of TCOPT coincidented with zero-level equation well and the character of controlled-release was transparent.Conclusion :TCOPT has good effect of controlled-release in vitro and the release behavior in vivo need to be inspected.

  15. Biosynthesis of a new tobacco alkaloid, hydroxy-N-acylnornicotine in the trichomes of Nicotiana stocktonii. [Manduca sexta

    Energy Technology Data Exchange (ETDEWEB)

    Zador, E.; Jones, D.

    1986-04-01

    A new tobacco alkaloid from section Repandae is highly toxic to an insect (Manduca sexta) unsusceptible to previously described nicotine alkaloids (1). They have localized the alkaloid, HO-N-acylnornicotine (HO-NAN) nearly entirely to the exudate secreted by the epidermal trichomes of N. stocktonii. Only the nicotine and nornicotine were found in abundance inside the trichomes, while primarily nicotine was present inside the aerial vegetative parts and root. These results suggest that the HO-NAN is synthesized by the trichomes. When unlabelled nicotine was fed to isolated leaves there was an increase in internal nicotine, nornicotine and secretion of HO-NAN. Feeding leaves with 2'-C/sup 14/ nicotine resulted in labelling of both nornicotine and HO-NAN. These data strongly suggest synthesis of HO-NAN from nicotine via nornicotine in the trichomes, followed by rapid secretion. The possible evolutionary significance of this pathway of synthesis and secretion is discussed.

  16. Relationships among Ergot Alkaloids, Cytochrome P450 Activity, and Beef Steer Growth

    Science.gov (United States)

    Rosenkrans, Charles; Ezell, Nicholas

    2015-03-01

    Determining a grazing animal’s susceptibility to ergot alkaloids has been a research topic for decades. Our objective was to determine if the Promega™ P450-Glo assay could be used to indirectly detect ergot alkaloids or their metabolites in urine of steers. The first experiment validated the effects of ergot alkaloids [0, 20, and 40 μM of ergotamine (ET), dihydroergotamine (DHET), and ergonovine (EN)] on human CYP3A4 using the P450-Glo assay (Promega™ V9800). With this assay, luminescence is directly proportional to CYP450 activity. Relative inhibition of in vitro cytochrome P450 activity was affected (P experiment 2, urine was collected from Angus-sired crossbred steers (n = 39; 216 ± 2.6 d of age; 203 ± 1.7 kg) after grazing tall fescue pastures for 105 d. Non-diluted urine was added to the Promega™ P450-Glo assay, and observed inhibition (3.7 % ± 2.7 of control). Urine content of total ergot alkaloids (331.1 ng/mg of creatinine ± 325.7) was determined using enzyme linked immunosorbent assay. Urine inhibition of CYP450 activity and total alkaloids were correlated (r = -0.31; P animals that are susceptible to ergot alkaloids. Although, additional research is needed, we demonstrate that the Promega™ P450-Glo assay is sensitive to ergot alkaloids and urine from steers grazing tall fescue. With some refinement the P450-Glo assay has potential as a tool for screening cattle for their exposure to fescue toxins.

  17. 半夏总生物碱对帕金森病大鼠学习记忆功能的影响及其机制的初步探讨%Effect of total alkaloid derived from Pinellia ternata on learning and memory and preliminary study of its mechanism in rats with Parkinson disease

    Institute of Scientific and Technical Information of China (English)

    周芳; 刁波; 段凯; 范圳涛; 张宜

    2011-01-01

    Objective To observe the effect of total alkaloid derived from Pinellia ternata on learning and memory and to study its mechanism in the rats with Parkinson disease (PD).Methods Fifty male rats were randomly divided into 5 groups of 10 animals each including normal group(A), control group(B), high dose treatment group(C), moderate dose treatment group(D) and low dose treatment group(E).The corresponding dose of total alkaloid derived from Pinellia ternate was infused into the animal stomach once every day for 8 weeks in all the treatment groups.The animal model of PD was established by subcutaneous injection of 1-methyl-4-phenyl-1, 2, 3,6-tetrahydropyridine (MPTP).The learning and memory were determined by water maze test in all the groups.The expressions of heat shock protein 70 (HSP70) and HSP70 mRNA in the substantia nigra were determined respectively by immunohistochemical technique and RT-PCR technique in all groups.Results The escape latency (EL) in groups A~E was (14.5± 1.05)s, (26.4±2.87)s, (19.8±3.31)s,(21.6±2.24)s and (25.5±4.48)s respectively.The levels of HSP70 expressions in groups A~E were (25.5±3.47) positive unit (PU), (27.4±5.82)PU, (42.3±5.27)PU, (35.4±6.8)PU and (29.6±4.97)PU respectively.The levels of HSP70 mRAN expressions in groups A~E were 0.4572±0.031, 0.5082±0.064, 0.6237±0.028, 0.5745 ±0.042 and 0.5181 ±0.055 respectively.EL was significantly shorter in groups A,C,and D.The levels of HSP70 and HSP70 mRNA expressions were significantly higher in groups C and D than those in group B (P<0.05).Conclusion The learning and memory may be improved by the total alkaloid derived from Pinellia ternate, by which upregulation of HSP70 expression in the suhstatia nigra may be related to improving the learning and memory in the rats with PD.%目的 观察半夏总生物碱对帕金森病(PD)大鼠学习记忆功能的影响并初步探讨其机制.方法 将50只清洁级级雄性Wistar大鼠随机分为五组,即正常组(A)、

  18. 杀结核菌素的全合成研究%An Improved Total Synthesis of Tubercidin

    Institute of Scientific and Technical Information of China (English)

    黄海洋; 阮志忠; 胡韬; 肖强

    2014-01-01

    Tubercidin is a naturally occurring pyrrolo[2,3-d]pyrimidine nucleoside with significantly biological activities, such as anti-schistosomal, antibacterial and antitumor. An improved total synthesis of tubercidin is reported using microwave promoted Vorbrüggen glycosylation as the key step. Thus, tubercidin was synthesized in 3 steps with 74%overal yield using 6-chloro-7-bromo-pyrrolo[2,3-d]pyrimidine and 1-O-acetyl-2,3,5-O-tribenzoyl-β-D-ribose as starting materials. The applica-tion of micromave irridated one-pot reaction is also reported in the synthesis of 7-deazapurine nucleosides using potassium nonafluoro-1-butanesulfonate, trimethylsilyl chloride and silylation reagent [hexamethyldisilazane or N,O-bis(trimethyl-silyl)acetamide].%杀结核菌素是一个吡咯[2,3-d]嘧啶核苷天然产物,具有显著的抗血吸虫感染、抗菌和抗肿瘤活性。报道了以微波促进的Vorbrüggen糖基化反应为关键步骤,以6-氯-7-溴-吡咯[2,3-d]嘧啶和1-O-乙酰基-2,3,5-O-三苯甲酰基-β-D-呋喃核糖为原料,经过3步反应以74%的总收率完成了杀结核菌素的全合成。同时研究了以全氟丁基磺酸钾、三甲基氯硅烷和硅基化试剂[六甲基二硅胺烷或者N,O-双(三甲基硅基)乙酰胺]在微波加热下一锅法合成7-去氮嘌呤核苷的方法。

  19. Evaluation of Antioxidant and Antibacterial Activities of Aqueous, Methanolic and Alkaloid Extracts from Mitragyna Speciosa (Rubiaceae Family Leaves

    Directory of Open Access Journals (Sweden)

    Mohd I. Mohd. Said

    2009-10-01

    Full Text Available Studies on the antioxidant and antimicrobial activities of Mitragyna speciosa leaf extracts are lacking. In this study the antioxidant properties of water, methanolic and alkaloid M. speciosa leaf extracts were evaluated using the DPPH (2,2-diphenyl-1- picrylhydrazyl radical scavenging method. The amount of total phenolics and flavanoid contents were also estimated. The DPPH IC50 values of the aqueous, alkaloid and methanolic extracts were 213.4, 104.81 and 37.08 μg/mL, respectively. The total phenolic content of the aqueous, alkaloid and methanolic extracts were 66.0 mg, 88.4, 105.6 mg GAE/g, respectively, while the total flavanoid were 28.2, 20.0 and 91.1 mg CAE/g respectively. The antioxidant activities were correlated with the total phenolic content. This result suggests that the relatively high antioxidant activity of the methanolic extract compared to aqueous and alkaloid extract could be possibly be due to its high phenolic content. The aqueous, alkaloid and methanolic extracts were screened for antimicrobial activity. The extracts showed antimicrobial activity against Salmonella typhi and Bacillus subtilis. The minimum inhibitory concentrations (MICs of extracts determined by the broth dilution method ranged from 3.12 to 6.25 mg/mL. The alkaloid extract was found to be most effective against all of the tested organisms.

  20. Main Alkaloids of Peganum harmala L. and Their Different Effects on Dicot and Monocot Crops

    Directory of Open Access Journals (Sweden)

    Chi Zhang

    2013-02-01

    Full Text Available Alkaloids with allelopathic activity are not as well-known as other allelochemicals. Our study revealed that total alkaloids from seeds of the medicinal plant Peganum harmala L. possessed significant growth inhibitory effect on four treated plants, with dicot plants (lettuce and amaranth being more sensitive than the tested monocot plants (wheat and ryegrass. Further investigation led to the isolation of harmaline and harmine as the main active ingredients in the total alkaloids of P. harmala seeds. Harmaline exerted potent inhibitory effects on seedling growth of treated plants, especially dicots, inhibiting root elongation of lettuce and amaranth by 31% and 47% at a very low concentration (5 µg/mL, whereas harmine exhibited much weaker non-selective inhibitory effect on the plants. Considering the high yield and poor utilization of P. harmala in China, we anticipate that this plant could be exploited as an alternative weed management tool in the future.

  1. Anxiolytic Activity of Diterpene Alkaloid Songorine.

    Science.gov (United States)

    Nesterova, Yu V; Povet'eva, T N; Suslov, N I; Shults, E E; Ziuz'kov, G N; Aksinenko, S G; Afanas'eva, O G; Krapivin, A V; Kharina, T G

    2015-09-01

    Antianxiety action of diterpene alkaloid songorine was studied using Vogel conflict test. Songorine in a dose of 0.25 mg/kg demonstrated high anxiolytic activity comparable to that of phenazepam and produced no sedative effect.

  2. A Facile Synthesis of Pyrrolidine Derivatives

    Institute of Scientific and Technical Information of China (English)

    SHAO Zhi-Hui; CHEN Jing-Bo; WANG Cheng-Ying; LIU Xiao-Long; REN Zhou-Yang; TU Yong-Qiang; ZHANG Hong-Bin

    2003-01-01

    @@ The Amaryllidaceae alkaloids have attracted considerable attention for their interesting biological activities. [1] Many of these tyrosine derived alkaloids[2] incorporate a hexahydroindole moiety in the structural skeletons. New approaches towards the synthesis of hexahydroindole core have been a topical interest for the synthetic community.Herein we report an experimentally very simple method for the synthesis of hexahydroindole by aminocylization. Four kinds of N-substituted have been demonstrate to be effective to this cyclization. The results were summarized in Figure 1.

  3. Enrichment and purification of six Aconitum alkaloids from Aconiti kusnezoffii radix by macroporous resins and quantification by HPLC-MS.

    Science.gov (United States)

    Liu, Jingjing; Li, Qing; Liu, Ran; Yin, Yidi; Chen, Xiaohui; Bi, Kaishun

    2014-06-01

    Aconitine, mesaconitine, hypaconitine, benzoylaconine, benzoylmesaconine and benzoylhypaconine are six main Aconitum alkaloids from traditional Chinese medicine, Aconiti kusnezoffii radix, which possess highly bioactive as well as highly toxic character for medicinal use. In the present study, for the purpose of better utilizing the toxic herbal material, the performance characteristics of NKA-II, D101, X-5, AB-8, S-8, HPD722 and HPD750 macroporous resins for the enrichment and purification of these six Aconitum alkaloids were critically evaluated. Results showed that NKA-II offered the best adsorption and desorption capacities for six Aconitum alkaloids among the seven macroporous resins tested, which were affected significantly by the pH value. Subsequently, dynamic adsorption and desorption experiments had been carried out with the column packed by NKA-II resin to optimize the separation process of six Aconitum alkaloids. After one run treatment with NKA-II resin, the content of total six Aconitum alkaloids were increased from 5.87% to 60.3%, the recovery was 75.8%. Meanwhile, a validated HPLC-MS method had been developed to qualitative and quantitative these six Aconitum alkaloids. This method would provide scientific references to the large-scale production of six Aconitum alkaloids from Aconiti kusnezoffii radix or other plants and might also expand the secure application of these highly toxic components for pharmacy. PMID:24814003

  4. Polycyclic alkaloids via transannular Mannich reactions

    DEFF Research Database (Denmark)

    Vital, Paulo; Hosseini, Masood; Shanmugham, M. S.;

    2009-01-01

    The tricyclic compound 13, representing the framework of the cylindricine 4 and lepadiformine 5 alkaloids, was prepared in a single operation via the first example of a transannular Mannich reaction involving a macrocyclic diketoamine 12.......The tricyclic compound 13, representing the framework of the cylindricine 4 and lepadiformine 5 alkaloids, was prepared in a single operation via the first example of a transannular Mannich reaction involving a macrocyclic diketoamine 12....

  5. Alkaloids from Fissistigma latifolium (Dunal) Merr.

    OpenAIRE

    Asmah Alias; Hazrina Hazni; Faridahanim Mohd Jaafar; Khalijah Awang; Nor Hadiani Ismail

    2010-01-01

    A phytochemical study of the bark of Fissistigma latifolium (Annonaceae) yielded a new aporphine alkaloid, (-)-N-methylguattescidine (1), and eight known alkaloids: liriodenine (2), oxoxylopine (3), (-)-asimilobine (4), dimethyltryptamine (5), (-)-remerine (6), (-)-anonaine (7), columbamine (8) and lysicamine (9). The compounds were isolated using various chromatographic methods and structural elucidation was accomplished by means of spectroscopic methods, notably 1D-NMR (1H, 13C, DEPT), 2D-N...

  6. Alkaloids from Fissistigma latifolium (Dunal Merr.

    Directory of Open Access Journals (Sweden)

    Asmah Alias

    2010-06-01

    Full Text Available A phytochemical study of the bark of Fissistigma latifolium (Annonaceae yielded a new aporphine alkaloid, (--N-methylguattescidine (1, and eight known alkaloids: liriodenine (2, oxoxylopine (3, (--asimilobine (4, dimethyltryptamine (5, (--remerine (6, (--anonaine (7, columbamine (8 and lysicamine (9. The compounds were isolated using various chromatographic methods and structural elucidation was accomplished by means of spectroscopic methods, notably 1D-NMR (1H, 13C, DEPT, 2D-NMR (COSY, HMQC, HMBC, UV, IR and MS.

  7. Ether bridge formation in loline alkaloid biosynthesis

    OpenAIRE

    Pan, Juan; Bhardwaj, Minakshi; Faulkner, Jerome R.; Nagabhyru, Padmaja; Charlton, Nikki D.; Higashi, Richard M.; Miller, Anne-Frances; Young, Carolyn A; Grossman, Robert B.; Schardl, Christopher L

    2013-01-01

    Lolines are potent insecticidal agents produced by endophytic fungi of cool-season grasses. These alkaloids are composed of a pyrrolizidine ring system and an uncommon ether bridge linking carbons 2 and 7. Previous results indicated that 1-aminopyrrolizidine was a pathway intermediate. We used RNA interference to knock down expression of lolO, resulting in the accumulation of a novel alkaloid identified as exo-1-acetamidopyrrolizidine based on high-resolution MS and NMR. Genomes of endophytes...

  8. Two new diterpene alkaloids from Delphinium chrysotrichum

    Institute of Scientific and Technical Information of China (English)

    Yang Qing He; Xiao Mei Wei; Yi Li Han; Li Ming Gao

    2007-01-01

    Chemical investigation on the ethanol extract from the whole plants of Delphinium chrysotrichum resulted in the isolation of two new diterpene alkaloids named delphatisine A (1) and delphatisine B (2), respectively. The structures of the new compounds were deduced on the basis of their spectral data (IR, HREIMS, EIMS, 1D, 2D-NMR). This is the first report on the isolation of diterpenoid alkaloids from the D. Chrysotrichum.

  9. Scientific Opinion on Ergot alkaloids in food and feed

    OpenAIRE

    EFSA Panel on Contaminants in the Food Chain (CONTAM)

    2012-01-01

    The European Food Safety Authority (EFSA) was asked by the European Commission to deliver a scientific opinion on ergot alkaloids (EAs) in food and feed. EAs are produced by several members within the fungal orders of Hypocreales and Eurotiales. In Europe, Claviceps purpurea is the most widespread Claviceps species within the Hypocreales. A total of 20 558 analytical results for EAs in 1 716 food, 496 feed and 67 unprocessed grain samples wer...

  10. Pharmacophore mapping in the laulimalide series: total synthesis of a vinylogue for a late-stage metathesis diversification strategy.

    Science.gov (United States)

    Wender, Paul A; Hilinski, Michael K; Skaanderup, Philip R; Soldermann, Nicolas G; Mooberry, Susan L

    2006-08-31

    An efficient synthesis of the macrocyclic core of laulimalide with a pendant vinyl group at C20 is described, allowing for late-stage introduction of various side chains through a selective and efficient cross metathesis diversification step. Representative analogues reported herein are the first to contain modifications to only the side chain dihydropyran of laulimalide and des-epoxy laulimalide. This step-economical strategy enables the rapid synthesis of new analogues using alkenes as an inexpensive, abundantly available diversification feedstock.

  11. Alkaloid Accumulation in Catharanthus roseus Increases with Addition of Seawater Salts to the Nutrient Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Jing-Yan; LIU Zhao-Pu

    2010-01-01

    A sand culture experiment was conducted to determine the effects of different seawater (5% and 10%) treatments on plant growth,inorganic ions,indole alkaloid concentrations and yields of Catharanthus roseus,in an effort to increase the alkaloid yield by artificial cultivation.The total fresh and dry weights and tissue K+ concentrations decreased,but Na+ concentrations increased in the plant roots,stems and leaves of C.roseus under seawater stress as compared to the control.The concentrations and yields of vindoline,catharanthine,vinblastine and vincristine increased under seawater stress.The concentrations and yields of these alkaloids were higher in 5% seawater-treated plants than those in the 10% seawater-treated plants.Considering the industrial production,5% seawater treatments could reduce the cost of producing alkaloid.In the control plants,the highest alkaloid concentrations reached a peak at 100 days after planting,suggesting that plant harvest must be optimized in terms of growth duration.

  12. Qualitative and quantitative analyses of alkaloids in Uncaria species by UPLC-ESI-Q-TOF/MS.

    Science.gov (United States)

    Wang, Hai-Bo; Qi, Wen; Zhang, Lin; Yuan, Dan

    2014-01-01

    An ultra performance liquid chromatography (UPLC) coupled with quadrupole time-of-flight mass spectrometry (Q-TOF/MS) method has been optimized and established for the rapid analysis of the alkaloids in 22 samples originating from five Uncaria (U.) species. The accurate mass measurement of all the protonated molecules and subsequent fragment ions offers higher quality structural information for the interpretation of fragmentation pathways of the various groups of alkaloids. A total of 19 oxindole alkaloids, 16 indole alkaloids and 1 flavone were identified by co-chromatography of the sample extract with authentic standards, comparison of the retention time, characteristic molecular ions and fragment ions, or were tentatively identified by MS/MS determination. Moreover, the method was validated for the simultaneous quantification of the 24 components within 10.5 min. The potential chemical markers were identified for classification of the U. species samples by principal component analysis (PCA) and orthogonal partial least squared discriminant analysis (OPLS-DA). The results demonstrate the similarity and differences in alkaloids among the five U. species, which is helpful for the standardization and quality control of the medical materials of the U. Ramulus Cum Unics (URCU). Furthermore, with multivariate statistical analysis, the determined markers are more definite and useful for chemotaxonomy of the U. genus. PMID:25366313

  13. Synthesis of Heterocyclic Ring Systems Using Organometallic Reagents

    Institute of Scientific and Technical Information of China (English)

    Sameer Agarwal; Jan Kn(o)ll; Micha P. Krahl; Hans-Joachim Kn(o)lker

    2005-01-01

    @@ 1Introduction We developed novel synthetic routes to heterocyclic ring systems by using transition metal-mediated or -catalyzed reactions. A Lewis acid-promoted addition of the propargyl Grignard reagent 2 to the Schiff base 1 followed by a silvermediated oxidative cyclization of the homopropargylamine 3 provided the aryl-substituted pyrrole 4. Combined with a chemoselective hydrogenation of the pyrrole ring, this method has been applied to the total synthesis of the biologically active fused indolizidine alkaloids ( ± )-harmicine and ( ± )-crispine A[1]. See Fig. 1.

  14. Improved method for the determination of oxindole alkaloids in Uncaria tomentosa by high performance liquid chromatography.

    Science.gov (United States)

    Ganzera, M; Muhammad, I; Khan, R A; Khan, I A

    2001-07-01

    This Paper describes an improved HPLC method for the determination of pentacyclic oxindole alkaloids in Uncaria tomentosa (Cat's Claw). Six of the isomeric compounds could be baseline separated at room temperature within less than 30 min by using 3 microm C-18 column material and a mobile phase consisting of 10 mM phosphate buffer at pH 7.0 and acetonitrile. At a wavelength of 245 nm all standard compounds could be detected at concentrations as low as 0.63 microg/ml. Different samples of U. tomentosa bark and market products containing Cat's Claw were extracted with a modified procedure ensuring the integrity of the alkaloids and analyzed successfully. The results indicated accuracy and consistency of the new method, and showed variations in the total alkaloid content in products from 0.156 to 0.962%.

  15. 粗叶悬钩子总生物碱对大鼠脂肪肝影响的脂肪染色图像分析%Image analysis on fat staining of fatty liver of rats with total alkaloids of Rubus Alceaefolius Poir

    Institute of Scientific and Technical Information of China (English)

    林如辉; 陈文列; 洪振丰; 黄关雅; 黄云梅; 徐柯

    2011-01-01

    Objective: To explore the effect on the fatty liver rats with the total alkaloids of Rubus Alceaefolius Poir (RAP) Methods: The 60 rats induced by CCl4 and treated by high fat diet. Then the rats divided six groups randomly: normal group,fatty liver model group, control by RAP low dose group, RAP medium dose group, RAP high dose group, Yishanfu group. The frozen sections were fat stained by Sudan Ⅳ, then observed the pathologic change in the treated groups, and quantitative analysis of the frozen section by positive areas, gray level, average optical density, integral optical density. Results: The treated groups by polysaccharides of RAP root and Yishanfu reduced and the pathologic change in the fatty liver rats , and the RAP high dose group reduced the gray level, average optical density and the integral optical density best, the difference was significant (P < 0. 05 ) . Conclusion: The RAP in high dose group can reduce the adipopexis in the fatty liver rats, and improve the pathological changes of fatty liver.%目的:探讨粗叶悬钩子(RAP)总生物碱对大鼠脂肪肝模型的影响.方法:以四氯化碳(CCl4)及高脂饮食造脂肪肝大鼠模型.将60只SD大鼠随机分为6组,即正常组,脂肪肝模型组,RAP总生物碱低剂量组、中剂量组、高剂量组,易善复对照组.观察各组大鼠经各种条件干预后肝脏冰冻切片的脂质变化,分别进行测量并定量分析脂肪染色阳性面积、灰度、平均光密度、积分光密度等.结果:RAP总生物碱各剂量组及易善复组均比模型组大鼠肝脏脂滴聚集变化轻,主要的测量指标平均灰度、平均光密度、积分光密度在高剂量组与模型组比较,差异具有显著性意义(P<0.05).结论:高剂量RAP总生物碱能减轻大鼠脂肪肝模型的脂滴聚集,改善脂肪肝的病变.

  16. Improved Total Synthesis and Biological Evaluation of Potent Apratoxin S4 Based Anticancer Agents with Differential Stability and Further Enhanced Activity

    OpenAIRE

    Chen, Qi-Yin; Liu, Yanxia; Cai, Weijing; Luesch, Hendrik

    2014-01-01

    Apratoxins are cytotoxic natural products originally isolated from marine cyanobacteria that act by preventing cotranslational translocation early in the secretory pathway to downregulate receptor levels and inhibit growth factor secretion, leading to potent antiproliferative activity. Through rational design and total synthesis of an apratoxin A/E hybrid, apratoxin S4 (1a), we have previously improved the antitumor activity and tolerability in vivo. Compound 1a and newly designed analogues a...

  17. Engineering biosynthesis of the anticancer alkaloid noscapine in yeast

    Science.gov (United States)

    Li, Yanran; Smolke, Christina D.

    2016-01-01

    Noscapine is a potential anticancer drug isolated from the opium poppy Papaver somniferum, and genes encoding enzymes responsible for the synthesis of noscapine have been recently discovered to be clustered on the genome of P. somniferum. Here, we reconstitute the noscapine gene cluster in Saccharomyces cerevisiae to achieve the microbial production of noscapine and related pathway intermediates, complementing and extending previous in planta and in vitro investigations. Our work provides structural validation of the secoberberine intermediates and the description of the narcotoline-4′-O-methyltransferase, suggesting this activity is catalysed by a unique heterodimer. We also reconstitute a 14-step biosynthetic pathway of noscapine from the simple alkaloid norlaudanosoline by engineering a yeast strain expressing 16 heterologous plant enzymes, achieving reconstitution of a complex plant pathway in a microbial host. Other engineered yeasts produce previously inaccessible pathway intermediates and a novel derivative, thereby advancing protoberberine and noscapine related drug discovery. PMID:27378283

  18. Synthesis and absolute configuration of a new 3,4-dihydro-beta-carboline-type alkaloid, 3,4-dehydro-5(S)-5-carboxystrictosidine, isolated from Peruvian Uña de Gato (Uncaria tomentosa).

    Science.gov (United States)

    Kitajima, Mariko; Yokoya, Masashi; Takayama, Hiromitsu; Aimi, Norio

    2002-10-01

    The structure including the absolute configuration of a new glucoalkaloid, 3,4-dehydro-5(S)-5-carboxystrictosidine, isolated from Peruvian Uña de Gato (Cat's Claw, original plant: Uncaria tomentosa), was confirmed by synthesis starting from secologanin and L-tryptophan.

  19. Benzylisoquinoline alkaloid biosynthesis in opium poppy.

    Science.gov (United States)

    Beaudoin, Guillaume A W; Facchini, Peter J

    2014-07-01

    Opium poppy (Papaver somniferum) is one of the world's oldest medicinal plants and remains the only commercial source for the narcotic analgesics morphine, codeine and semi-synthetic derivatives such as oxycodone and naltrexone. The plant also produces several other benzylisoquinoline alkaloids with potent pharmacological properties including the vasodilator papaverine, the cough suppressant and potential anticancer drug noscapine and the antimicrobial agent sanguinarine. Opium poppy has served as a model system to investigate the biosynthesis of benzylisoquinoline alkaloids in plants. The application of biochemical and functional genomics has resulted in a recent surge in the discovery of biosynthetic genes involved in the formation of major benzylisoquinoline alkaloids in opium poppy. The availability of extensive biochemical genetic tools and information pertaining to benzylisoquinoline alkaloid metabolism is facilitating the study of a wide range of phenomena including the structural biology of novel catalysts, the genomic organization of biosynthetic genes, the cellular and sub-cellular localization of biosynthetic enzymes and a variety of biotechnological applications. In this review, we highlight recent developments and summarize the frontiers of knowledge regarding the biochemistry, cellular biology and biotechnology of benzylisoquinoline alkaloid biosynthesis in opium poppy. PMID:24671624

  20. Hemlock alkaloids from Socrates to poison aloes.

    Science.gov (United States)

    Reynolds, Tom

    2005-06-01

    Hemlock (Conium maculatum L. Umbelliferae) has long been known as a poisonous plant. Toxicity is due to a group of piperidine alkaloids of which the representative members are coniine and gamma-coniceine. The latter is the more toxic and is the first formed biosynthetically. Its levels in relation to coniine vary widely according to environmental conditions and to provenance of the plants. Surprisingly, these piperidine alkaloids have turned up in quite unrelated species in the monocotyledons as well as the dicotyledons. Aloes, for instance, important medicinal plants, are not regarded as poisonous although some species are very bitter. Nevertheless a small number of mostly local species contain the alkaloids, especially gamma-coniceine and there have been records of human poisoning. The compounds are recognized by their characteristic mousy smell. Both acute and chronic symptoms have been described. The compounds are neurotoxins and death results from respiratory failure, recalling the effects of curare. Chronic non-lethal ingestion by pregnant livestock leads to foetal malformation. Both acute and chronic toxicity are seen with stock in damp meadows and have been recorded as problems especially in North America. The alkaloids derive biosynthetically from acetate units via the polyketide pathway in contrast to other piperidine alkaloids which derive from lysine.

  1. Two New C19-Diterpenoid Alkaloids from Delphinium davidii Franch.

    Institute of Scientific and Technical Information of China (English)

    Xiao Xia LIANG; Dong Lin CHEN; Feng Peng WANG

    2006-01-01

    Two new C19-diterpenoid alkaloids, davidisines A (1) and B (2) along with thirteen known alkaloids were isolated from the whole herb of Delphinium davidii Franch. Their structures were established by spectral methods, especially 2D NMR techniques.

  2. Biosynthesis of Monoterpenoid Indole Alkaloid Ajmaline Catalyzed by Novel Reductases

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Introduction One of the major root alkaloids of the Indian medicinal plant Rauvolfia serpenlina Benth. Ex Kurz is named ajmaline. The enzymatic biosynthesisof this alkaloid has been studied for a long time by our group[1].

  3. Biological activity of alkaloids from Solanum dulcamara L.

    Science.gov (United States)

    Kumar, Padma; Sharma, Bindu; Bakshi, Nidhi

    2009-01-01

    Alkaloids are well known for their antimicrobial activity. Though all natural alkaloids come from plants, not all plants produce alkaloids. Plants of the Solanaceae family are known for their high alkaloid content. Alkaloids are found in all plant parts like roots, stems, leaves, flowers, fruits and seeds. In the present study, those plant parts of Solanum dulcamara were selected which have been reported to produce a high content of a specific alkaloid: solanine (from unripe fruits), solasodine (from flowers) and beta-solamarine (from roots). These alkaloids were extracted from various parts of S. dulcamara by well-established methods and were screened for their antibacterial activity. Human pathogenic bacteria, viz., Enterobacter aerogenes, Escherichia coli, Staphylococcus aureus, were selected for the study. All three alkaloids inhibited the growth of E. coli and S. aureus. However, no significant activity was observed against E. aerogenes. Minimum inhibitory concentration and minimum bactericidal concentration were also evaluated.

  4. Monoterpenoid Indole Alkaloids from Catharanthus roseus Cultivated in Yunnan.

    Science.gov (United States)

    Wang, Bei; Liu, Lu; Chen, Ying-ying; Li, Qiong; Li, Dan; Liu, Va-ping; Luo, Xiao-dong

    2015-12-01

    A new monoterpenoid indole alkaloid, 15,20-dehydro-3α-(2-oxopropyl) coronaridine (1), along with sixteen analogues (2-17) were isolated from the leaves of Catharanthus roseus cultivated in Yunnan. The new alkaloid was elucidated on the basis of extensive spectroscopic analysis, and the known alkaloids were identified by comparison with the reported spectroscopic data. Among them, alkaloid 16 was isolated from Catharanthus for the first time. PMID:26882670

  5. Stereoselective synthesis of (E)-beta-tributylstannyl-alpha,beta-unsaturated ketones: Construction of a key intermediate for the total synthesis of zoanthamine

    DEFF Research Database (Denmark)

    Nielsen, Thomas Eiland; Tanner, David Ackland

    2002-01-01

    (E)-beta-Trialkylstannyl-alpha,beta-unsaturated ketones are readily available from secondary propargylic alcohols via a two-step sequence involving highly regio- and stereoselective Pd(0)-catalyzed hydrostannation followed by mild oxidation (TPAP). The methodology has been applied to the synthesi...

  6. Antagonistic effects of total alkaloids of Lianzixin and their methyl-derivative on stretch-induced arrhythmia%莲心总碱及其甲基化物对牵张性心律失常的拮抗效应

    Institute of Scientific and Technical Information of China (English)

    马嵘; 贺斌; 赵春虎; 王嘉陵; 向继洲

    2004-01-01

    目的澄清莲心总碱(TAL)与氨基糖苷类抗生素的共同化学结构带正电的氨基是否使之具有抗牵张性心律失常的共同效应.方法通过膨胀心室腔内的球囊、夹闭升主动脉和牵拉乳头肌建立心律失常、动作电位时程的缩短和触发活动的模型.采用离体心电图、细胞内微电极和在体单相动作电位的标准技术进行记录.结果①TAL和甲基莲心总碱(TMAL)(2.5, 5 和 10 μmol·L-1)能剂量依赖性的缩短大鼠离体心脏牵张性心律失常的持续时间,从对照组的(2.16±0.38)s减少到(1.53±0.14), (0.93±0.21), (0.52±0.35)s (TAL)和(1.59±0.16), (0.94±0.21), (0.79±0.15)s (TMAL).②在麻醉豚鼠,TAL 2.3 mg·kg-1 iv和TMAL 2.6 mg·kg-1 iv能显著抑制夹闭主动脉引起的单相动作电位50%和90%复极时程的缩短及触发活动的发生率,分别从(28.9±8.1)% 减少到(5.4±1.2)%和(10.8±2.3)%.③TAL和TMAL也能显著抑制牵拉豚鼠乳头肌所致的动作电位50%和90%复极时程的缩短.结论 TAL和TMAL能抑制牵张性心律失常和牵张引起的动作电位的改变,这种作用可能是通过阻断牵张活化的离子通道实现的.%AIM To clarify whether the common chemical structure-the positive-charged amino groups of total alkaloids of Lianzixin(TAL) and aminoglycosides antibiotics renders them possessing common antagonistic effects on stretch-induced arrhythmia. METHODS The kind of arrhythmia, shortening of action potential duration(APD) and triggered activity(TA) models were established by inflating the intracavitary balloon, clamping the ascending aorta and by stretching ventricular papillary muscle, transiently. Standard techniques of electrocardiogram(ECG), monophasic action potential(MAP) and intracellular microelectrode recording were used in vivo and in vitro. RESULTS ①TAL and total methyl alkaloids of Lianzixin(TMAL) 2.5, 5 and 10 μmol·L-1 concentration-dependently reduced the persistent duration of stretch

  7. Two New Alkaloids from Narcissus serotinus L.

    Directory of Open Access Journals (Sweden)

    Francesc Viladomat

    2010-10-01

    Full Text Available The Amaryllidaceae family is well known for the presence of an exclusive group of alkaloids with a wide range of biological activities. Narcissus serotinus L. is a plant belonging to this family and its geographical distribution is mainly located along the Mediterranean coast. In the present work, specimens collected near Casablanca (Morocco were used to study the alkaloid content of this species. Starting with 350 g of the whole plant we used standard extraction and purification procedures to obtain fractions and compounds for GC-MS and NMR analysis. As well as five known alkaloids, we isolated two new compounds: 1-O-(3´-acetoxybutanoyllycorine and narseronine. The latter has been previously published, but with an erroneous structure.

  8. Aporphine alkaloids from Ocotea macrophylla (Lauraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Pabon, Ludy Cristina; Cuca, Luis Enrique, E-mail: lcpabonb@unal.edu.c [Universidad Nacional de Bogota (Colombia). Facultad de Ciencias. Dept. de Quimica

    2010-07-01

    Four aporphine alkaloids from the wood of Ocotea macrophylla (Lauraceae) were isolated and characterized as (S)-3-methoxy-nordomesticine (1), (S)-N-ethoxycarbonyl-3-methoxy-nordomesticine (2), (S)-N-formyl-3-methoxy-nordomesticine (3) and (S)-N-methoxycarbonyl-3-methoxy-nordomesticine (4); alkaloids 2-4 are being report for the first time. The structure the isolated compounds were determined based on their spectral data and by comparison of their spectral data with values described in literature. The alkaloid fraction and compound 1 showed antifungal activity against Fusarium oxysporum f. sp. lycopersici and also compound 1 showed antimicrobial activity towards Staphylococcus aureus, Enterococcus faecalis as well. (author)

  9. Aporphine alkaloids from Ocotea macrophylla (Lauraceae

    Directory of Open Access Journals (Sweden)

    Ludy Cristina Pabon

    2010-01-01

    Full Text Available Four aporphine alkaloids from the wood of Ocotea macrophylla (Lauraceae were isolated and characterized as (S-3-methoxy-nordomesticine (1, (S-N-ethoxycarbonyl-3-methoxy-nordomesticine (2, (S-N-formyl-3-methoxy-nordomesticine (3 and (S-N-methoxycarbonyl-3-methoxy-nordomesticine (4; alkaloids 2-4 are being report for the first time. The structure the isolated compounds were determined based on their spectral data and by comparison of their spectral data with values described in literature. The alkaloid fraction and compound 1 showed antifungal activity against Fusarium oxysporum f. sp. lycopersici and also compound 1 showed antimicrobial activity towards Staphylococcus aureus, Enterococcus faecalis as well.

  10. Antibacterial and antifungal activity of liriodenine and related oxoaporphine alkaloids.

    Science.gov (United States)

    Hufford, C D; Sharma, A S; Oguntimein, B O

    1980-10-01

    Liriodenine was evaluated for its antibacterial and antifungal activity against several microorganisms. Other related oxoaporphine alkaloids also were evaluated. Attempts to prepare oxoaporphine alkaloids from N-acetylnoraporphines were unsuccessful, but an unexpected phenanthrene alkaloid was obtained. A novel N-demethylation reaction was noted when oxogaucine methiodide and liriodenine methiodide were treated with alumina. PMID:7420287

  11. Advances in total synthesis: A new approach to the synthesis of pteridic acids A and B [Avanços em síntese total: Uma nova abordagem para a síntese dos ácidos pterídicos A e B

    Directory of Open Access Journals (Sweden)

    David Rodrigues da Rocha

    2009-08-01

    Full Text Available This communication overview the total synthesis of pteridic acids A and B recently published by L. C. Dias and A. G. Salles Jr.in The Journal of Organic Chemistry which was achieved by a new synthetic route. These natural products are among the mostcomplex molecules already synthesized in Brazil.

  12. Antimicrobial hasubanalactam alkaloid from Stephania glabra.

    Science.gov (United States)

    Semwal, Deepak Kumar; Rawat, Usha

    2009-03-01

    A novel hasubanalactam alkaloid, named glabradine, has been isolated from the tubers of Stephania glabra, together with three known quaternary protoberberine alkaloids, palmatine, dehydrocorydalmine and stepharanine. The structure of glabradine was assigned as 7-O-demethyl-N,O-dimethyloxostephinine, by means of rigorous spectroscopic analysis including 2 D NMR measurements. It was evaluated for antimicrobial activity against Staphylococcus aureus, S. mutans, Microsporum gypseum, M. canis and Trichophyton rubrum and displayed potent antimicrobial activity superior to those of novobiocin and erythromycin used as positive controls. PMID:19148860

  13. Antiprotozoal alkaloids from Psychotria prunifolia (Kunth) Steyerm

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Lucilia; Oliveira, Cecilia M.A. de; Faria, Emiret O.; Ribeiro, Laryssa C.; Carvalho, Brenda G., E-mail: lucilia@quimica.ufg.br [Instituto de Quimica, Universidade Federal de Goias, Campus II, Samambaia, Goiania, GO (Brazil); Silva, Cleuza C. da; Santin, Silvana M.O. [Departamento de Quimica, Universidade Estadual de Maringa, Maringa, PR (Brazil); Schuque, Ivania T.A.; Nakamura, Celso V.; Britta, Elisandra A.; Miranda, Nathielle [Departamento de Farmacia e Farmacologia, Universidade Estadual de Maringa, PR (Brazil); Iglesias, Amadeu H. [Waters Technologies do Brasil LTDA, Barueri, SP (Brazil); Delprete, Piero G. [VHerbier de Guyane, Institut de Recherche pour le Developpement (IRD), UMR AMAP, French Guiana (France)

    2012-07-01

    The continuity of the phyto chemical study of crude extracts of P. prunifolia's roots and branches led to the isolation of five indole-{beta}-carboline alkaloids. Among them, the 10-hydroxy-iso-deppeaninol and N-oxide-10-hydroxy-antirhine derivatives are described here for the first time. The structures were achieved through 1D and 2D NMR, IR and HRMS analyses. The branches and roots crude extracts and the alkaloids 14-oxoprunifoleine and strictosamide showed selective activity against L. amazonensis, with IC{sub 50} values of 16.0 and 40.7 {mu}g per mL, respectively. (author)

  14. Relationships among Ergot Alkaloids, Cytochrome P450 Activity, and Beef Steer Growth

    Directory of Open Access Journals (Sweden)

    Charles F. Rosenkrans

    2015-03-01

    Full Text Available Determining a grazing animal’s susceptibility to ergot alkaloids has been a research topic for decades. Our objective was to determine if the Promega™ P450-Glo assay could be used to indirectly detect ergot alkaloids or their metabolites in urine of steers. The first experiment validated the effects of ergot alkaloids [0, 20, and 40 μM of ergotamine (ET, dihydroergotamine (DHET, and ergonovine (EN] on human CYP3A4 using the P450-Glo assay (Promega™ V9800. With this assay, luminescence is directly proportional to CYP450 activity. Relative inhibition of in vitro cytochrome P450 activity was affected (P < 0.001 by an interaction between alkaloids and concentration. That interaction resulted in no concentration effect of EN, but within ET and DHET 20 and 40 µM concentrations inhibited CYP450 activity when compared with controls. In experiment 2, urine was collected from Angus-sired crossbred steers (n = 39; 216 ± 2.6 d of age; 203 ± 1.7 kg after grazing tall fescue pastures for 105 d. Non-diluted urine was added to the Promega™ P450-Glo assay, and observed inhibition (3.7 % ± 2.7 of control. Urine content of total ergot alkaloids (331.1 ng/mg of creatinine ± 325.7 was determined using enzyme linked immunosorbent assay. Urine inhibition of CYP450 activity and total alkaloids were correlated (r = -0.31; P < 0.05. Steers were genotyped at CYP450 single nucleotide polymorphism, C994G. Steer genotype affected (P < 0.03 inhibition of CYP450 activity by urine; heterozygous steers had the least amount of CYP450 inhibition suggesting that genotyping cattle may be a method of identifying animals that are susceptible to ergot alkaloids. Although, additional research is needed, we demonstrate that the Promega™ P450-Glo assay is sensitive to ergot alkaloids and urine from steers grazing tall fescue. With some refinement the P450-Glo assay has potential as a tool for screening cattle for their exposure to fescue toxins.

  15. Quantitative Determination of Alkaloids in Lotus Flower (Flower Buds of Nelumbo nucifera and Their Melanogenesis Inhibitory Activity

    Directory of Open Access Journals (Sweden)

    Toshio Morikawa

    2016-07-01

    Full Text Available A quantitative analytical method for five aporphine alkaloids, nuciferine (1, nornuciferine (2, N-methylasimilobine (3, asimilobine (4, and pronuciferine (5, and five benzylisoquinoline alkaloids, armepavine (6, norarmepavine (7, N-methylcoclaurine (8, coclaurine (9, and norjuziphine (10, identified as the constituents responsible for the melanogenesis inhibitory activity of the extracts of lotus flowers (the flower buds of Nelumbo nucifera, has been developed using liquid chromatography-mass spectrometry. The optimum conditions for separation and detection of these 10 alkaloids were achieved on a πNAP column, a reversed-phase column with naphthylethyl group-bonded silica packing material, with CH3CN–0.2% aqueous acetic acid as the mobile phase and using mass spectrometry equipped with a positive-mode electrospray ionization source. According to the protocol established, distributions of these 10 alkaloids in the petal, receptacle, and stamen parts, which were separated from the whole flower, were examined. As expected, excellent correlations were observed between the total alkaloid content and melanogenesis inhibitory activity. Among the active alkaloids, nornuciferine (2 was found to give a carbamate salt (2′′ via formation of an unstable carbamic acid (2′ by absorption of carbon dioxide from the air.

  16. The Effect of Prolonged Fasting on Total Lipid Synthesis and Enzyme Activities in the Liver of the European Eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Abraham, S. A.; Hansen, Heinz Johs. Max; Hansen, F.N.

    1984-01-01

    The extent of fatty acid synthesis from [1-14C]acetate in liver slices was reduced 6-fold when eels were fasted for 1-7 wk and 20-fold when fasted for 39 wk, thereafter hepatic lipogenesis seemed to remain constant for up to 95 wk of fasting. After a 1-3 wk fast some hepatic enzyme activities were...... total lipid synthesis and lipogenic enzyme activity in eel liver was 30.degree. C....... reduced (acetyl-CoA carboxylase decreased 2-fold and fatty acid synthetase declined 5-fold); others remained unchanged (G-6-P dehydrogenase, 6-phosphogluconate dehydrogenase, .alpha.-glycerol phosphate dehydrogenase as well as malic enzyme and ATP-citrate lyase). The optimum temperature for measuring both...

  17. Bringing the science of proteins into the realm of organic chemistry: total chemical synthesis of SEP (synthetic erythropoiesis protein).

    Science.gov (United States)

    Kent, Stephen B H

    2013-11-11

    Erythropoietin, commonly known as EPO, is a glycoprotein hormone that stimulates the production of red blood cells. Recombinant EPO has been described as "arguably the most successful drug spawned by the revolution in recombinant DNA technology". Recently, the EPO glycoprotein molecule has re-emerged as a major target of synthetic organic chemistry. In this article I will give an account of an important body of earlier work on the chemical synthesis of a designed EPO analogue that had full biological activity and improved pharmacokinetic properties. The design and synthesis of this "synthetic erythropoiesis protein" was ahead of its time, but has gained new relevance in recent months. Here I will document the story of one of the major accomplishments of synthetic chemistry in a more complete way than is possible in the primary literature, and put the work in its contemporaneous context.

  18. Enantioselective organocatalytic formal [3 + 3]-cycloaddition of alpha,beta-unsaturated aldehydes and application to the asymmetric synthesis of (-)-isopulegol hydrate and (-)-cubebaol.

    Science.gov (United States)

    Hong, Bor-Cherng; Wu, Ming-Fun; Tseng, Hsing-Chang; Liao, Ju-Hsiou

    2006-05-25

    [reaction: see text] The first highly enantioselective organocatalyzed carbo [3 + 3] cascade cycloaddition of alpha,beta-unsaturated aldehydes is reported. Using this methodology, crotonaldehyde is converted to 6-hydroxy-4-methylcyclohex-1-enecarbaldehyde, which is used in the synthesis of (-)-isopulegol hydrate, (-)-cubebaol, and p-tolualdehyde as well as (-)-6-hydroxy-4-methyl-1-cyclohexene-1-methanol acetate, an intermediate in the total synthesis of lycopodium alkaloid magellanine. Other alpha,beta-unsaturated aldehydes give rise to chiral cyclohexadienes via formal [4 + 2] reactions. PMID:16706490

  19. A New Quinolizidine Alkaloid from Boehmeria siamensis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new quinolizidine alkaloid, 3-(4-hydroxyphenyl)-4-(3-methoxy-4-hydroxyphenyl)-3, 4-dehydroquinolizidine (1), was isolated from the ethanol extract of the whole plants of Boehmeria siamensis Craib. Its structure was elucidated on the analysis of 1D NMR and 2D NMR spectrum.

  20. Two New Oxoaporphine Alkaloids from Thalictrum elegans

    Institute of Scientific and Technical Information of China (English)

    梁志远; 杨小生; 汪冶; 郝小江

    2005-01-01

    Two new oxoaporphine alkaloids, 1,2,3,10-tetramethoxy-9-(2-hydroxy-4,5-dimethoxybenzyloxy)oxoaporphine (1) and 1,2,3,10-tetramethoxy-9-(4,5-dimethoxy-2-formylphenoxy)oxoaporphine (2), were isolated from Thalictrum elegans. Their structures were elucidated based on spectroscopic analysis including 1D, 2D NMR, IR and MS.

  1. Saponins and alkaloids from Abuta grandifolia

    OpenAIRE

    Sayagh, C.; Long, C; Moretti, Christian; Lavaud, C.

    2012-01-01

    Five new bidesmosidic saponins (1-5), along with six known triterpenoid saponins, were isolated from the methanolic extracts of the leaves and twigs of Abuta grandifolia. The ethyl acetate extracts allowed the isolation of three tropoloisoquinolines and of one isoquinoline; all were known alkaloids. The structures of all compounds were elucidated on the basis of extensive spectroscopic data analysis.

  2. A New Alkaloid from Sinomenium acutum

    Institute of Scientific and Technical Information of China (English)

    Wei Ming CHENG; Feng QIU; Li Jun WU; Xin Sheng YAO

    2005-01-01

    Sinomenium acutum is widely used in East and South Asia for the treatment of many diseases, especially rheumatoid arthritis (RA). The chemical research on Sinomenium acutum led to the isolation of a new alkaloid compound (1). On the basis of chemical evidences and spectral analysis, 1 was identified as N-(1, 7-dimethoxylphenanthren-2-yl)acetamide.

  3. Histrionicotoxin alkaloids finally detected in an ant

    DEFF Research Database (Denmark)

    Jones, Tappey H.; Adams, Rachelle Martha Marie; Spande, Thomas F.;

    2012-01-01

    Workers of the ant Carebarella bicolor collected in Panama were found to have two major poison-frog alkaloids, cis- and trans-fused decahydroquinolines (DHQs) of the 269AB type, four minor 269AB isomers, two minor 269B isomers, and three isomers of DHQ 271D. For the first time in an ant, however......, the DHQs were accompanied by six histrionicotoxins (HTXs), viz., 283A, 285A, 285B, 285C, 287A, and 287D. This co-occurrence of the HTX and DHQ alkaloids is the usual pattern seen in dendrobatid frogs. This finding contrasts with our earlier study, where workers of a Brazilian ant, Solenopsis (Diplorhoptrum......) sp., were found to have a very similar DHQ complex but failed to show HTXs. Several new DHQ alkaloids of MW 271 (named in the frog as 271G) are reported from the above ants that have both m/z 202 and 204 as major fragment ions, unlike the spectrum seen for the poison-frog alkaloid 271D, which has...

  4. Acetylcholinesterase-inhibiting Alkaloids from Zephyranthes concolor

    Directory of Open Access Journals (Sweden)

    Sebastien Arseneau

    2011-11-01

    Full Text Available The bulbs and aerial parts of Zephyranthes concolor (Lindl. Benth. & Hook. f. (Amaryllidaceae, an endemic species to Mexico, were found to contain the alkaloids chlidanthine, galanthamine, galanthamine N-oxide, lycorine, galwesine, and epinorgalanthamine. Since currently only partial and low resolution 1H-NMR data for chlidanthine acetate are available, and none for chlidanthine, its 1D and 2D high resolution 1H- and 13C-NMR spectra were recorded. Unambiguous assignations were achieved with HMBC, and HSQC experiments, and its structure was corroborated by X-ray diffraction. Minimum energy conformation for structures of chlidanthine, and its positional isomer galanthamine, were calculated by molecular modelling. Galanthamine is a well known acetylcholinesterase inhibitor; therefore, the isolated alkaloids were tested for this activity. Chlidanthine and galanthamine N-oxide inhibited electric eel acetylcholinesterase (2.4 and 2.6 × 10−5 M, respectively, indicating they are about five times less potent than galanthamine, while galwesine was inactive at 10−3 M. Inhibitory activity of HIV-1 replication, and cytotoxicity of the isolated alkaloids were evaluated in human MT-4 cells; however, the alkaloids showed poor activity as compared with standard anti-HIV drugs, but most of them were not cytotoxic.

  5. Catharanthus roseus (L. G. Don - plant regeneration and alkaloids content

    Directory of Open Access Journals (Sweden)

    Mirosława Furmanowa

    2014-02-01

    Full Text Available We describe here a regeneration of plantlets of Catharanthus roseus (L. G. Don from shoot tips and axillary buds. Shoot tips were excised from 7-day-old seedlings and were incubated in solid Nitsch and Nitsch (NN medium supplemented with kinetin, benzyladenine (BA, indole-3-butyric acid (IBA and β-indolylacetic acid (IAA in various combinations. After two months in culture, regenerated rooted plantlets were cut and transferred to a new medium; the explants contained shoot tips or axillary buds. Four passages were done. We obtained about 200 rooting plantlets from one seedling. Then the plantlets were transferred to the soil and they grew under a foil tent. After five months of vegetation they were collected, dried and weighed. Chemical investigations of leaves of these plants were done. The vindoline and catharanthine were dominant alkaloids in the juvenile stage of plants (before blooming. Total amount of alkaloids, equal 2.95%, was gravimetrically determined in leaves of plants, after 4th passage, regenerated in vitro on NN medium supplemented with kinetin and IBA.

  6. Proliferation inhibition and apoptosis induction effects of total alkaloid of Sophora Alopecuroides on mouse mammary tumor 4T1 cells in vitro%苦豆子总生物碱对小鼠乳腺癌4T1细胞体外增殖抑制及诱导凋亡作用的研究

    Institute of Scientific and Technical Information of China (English)

    李建光; 牛清芝; 杨晓艺; 曾诚; 黄伟

    2015-01-01

    Objective To explore the proliferation inhibition and apoptosis effect of the total alkaloid of so-phora alopecuroides (TASA)on mouse mammary tumor 4T1 in vitro.Methods TASA was extracted and purified,and then TASA was administrated to mouse mammary tumor 4T1 cells.The inhibitory effect of TASA at different concentrations on 4T1 cells was determinated by CCK-8 assay at the time point of 24 h. The effect of TASA on 4T1 cells apoptosis was detected by flow cytometry.Results With the drug con-centration of 5.00 mg/mL,4T1 cells survival rate was 63.05%,while the drug concentration reached to 10.00 mg/mL,4T1 cells survival rate was 20.30%,which suggested that 4T1 cells survival rate signifi-cantly declined with the increase of drug concentration.With the drug concentration of 6 .2 5 mg/mL,the apoptosis rate was 11.4%,while the drug concentration was 10.00 mg/mL,the apoptosis rate was 41.7%, which showed that apoptosis rate was increased significantly with the drug level increasing.Conclusion TASA could induce cell apoptosis of 4T1 cells,and it had a remarkable inhibitory effect on the prolifera-tion of 4T1 cells.%目的:研究苦豆子总生物碱对小鼠乳腺癌4T1细胞体外增殖抑制及诱导凋亡作用。方法苦豆子总生物碱提取并纯化,处理成澄清的药物溶液后用于细胞给药。CCK-8法测定不同浓度的苦豆子总生物碱作用24 h后4T1细胞存活率。流式细胞术检测给药24 h后4T1细胞凋亡率。结果与对照组比较,实验组药物浓度为5.00 mg/mL时,4T1细胞存活率为63.05%;药物浓度为10.00 mg/mL时,4T1细胞存活率为20.30%,随着给药浓度的增加,细胞存活率呈明显下降趋势。实验组药物浓度为6.25 mg/mL时,细胞凋亡率为11.4%;药物浓度为10.00 mg/mL时,细胞凋亡率为41.7%,随着给药浓度的增加,细胞凋亡率明显增加。结论苦豆子总生物碱能诱导细胞凋亡,对小鼠乳腺癌4T1细胞的增殖有明显抑制作用。

  7. Diverted Total Synthesis of Promysalin Analogs Demonstrates That an Iron-Binding Motif Is Responsible for Its Narrow-Spectrum Antibacterial Activity.

    Science.gov (United States)

    Steele, Andrew D; Keohane, Colleen E; Knouse, Kyle W; Rossiter, Sean E; Williams, Sierra J; Wuest, William M

    2016-05-11

    Promysalin is a species-specific Pseudomonad metabolite with unique bioactivity. To better understand the mode of action of this natural product, we synthesized 16 analogs utilizing diverted total synthesis (DTS). Our analog studies revealed that the bioactivity of promysalin is sensitive to changes within its hydrogen bond network whereby alteration has drastic biological consequences. The DTS library not only yielded three analogs that retained potency but also provided insights that resulted in the identification of a previously unknown ability of promysalin to bind iron. These findings coupled with previous observations hint at a complex multifaceted role of the natural product within the rhizosphere.

  8. Total synthesis of (+)-discodermolide: an improved endgame exploiting a Still-Gennari-type olefination with a C1-C8 beta-ketophosphonate fragment.

    Science.gov (United States)

    Paterson, Ian; Lyothier, Isabelle

    2004-12-23

    [structure: see text] An improved, third-generation, total synthesis of (+)-discodermolide, a potent microtubule-stabilizing anticancer agent of marine sponge origin, is achieved in 11.1% yield over 21 steps. Key steps include a Still-Gennari HWE olefination, performed using NaH as the base, between C1-C8 beta-ketophosphonate 7 and C9-C24 aldehyde 8, introducing the (8Z)-alkene with 10:1 selectivity, and K-Selectride reduction of the derived enone 16, installing the (7S)-configuration.

  9. Radical Beckmann Rearrangement and Its Application in the Formal Total Synthesis of Antimalarial Natural Product Isocryptolepine via C-H Activation.

    Science.gov (United States)

    Mahajan, Pankaj S; Humne, Vivek T; Tanpure, Subhash D; Mhaske, Santosh B

    2016-07-15

    The Beckmann rearrangement of ketoximes, mediated by ammonium persulfate-dimethyl sulfoxide as a reagent, has been achieved under neutral conditions. Based on the radical trapping and (18)O-labeling experiments, the transformation follows a mechanism involving a radical pathway. The scope and generality of the developed protocol has been demonstrated by 19 examples. The developed protocol and Pd-catalyzed intramolecular double C-H activation were used as key steps in the formal total synthesis of antimalarial natural product isocryptolepine. PMID:27377995

  10. Influence of Precursor Availability on Alkaloid Accumulation by Transgenic Cell Line of Catharanthus roseus1

    Science.gov (United States)

    Whitmer, Serap; Canel, Camilo; Hallard, Didier; Gonçalves, Cecilia; Verpoorte, Robert

    1998-01-01

    We have used a transgenic cell line of Catharanthus roseus (L.) G. Don to study the relative importance of the supply of biosynthetic precursors for the synthesis of terpenoid indole alkaloids. Line S10 carries a recombinant, constitutively overexpressed version of the endogenous strictosidine synthase (Str) gene. Various concentrations and combinations of the substrate tryptamine and of loganin, the immediate precursor of secologanin, were added to suspension cultures of S10. Our results indicate that high rates of tryptamine synthesis can take place under conditions of low tryptophan decarboxylase activity, and that high rates of strictosidine synthesis are possible in the presence of a small tryptamine pool. It appears that the utilization of tryptamine for alkaloid biosynthesis enhances metabolic flux through the indole pathway. However, a deficiency in the supply of either the iridoid or the indole precursor can limit flux through the step catalyzed by strictosidine synthase. Precursor utilization for the synthesis of strictosidine depends on the availability of the cosubstrate; the relative abundance of these precursors is a cell-line-specific trait that reflects the metabolic status of the cultures. PMID:9490777

  11. Rhizoma Coptidis alkaloids alleviate hyperlipidemia in B6 mice by modulating gut microbiota and bile acid pathways.

    Science.gov (United States)

    He, Kai; Hu, Yinran; Ma, Hang; Zou, Zongyao; Xiao, Yubo; Yang, Yong; Feng, Min; Li, Xuegang; Ye, Xiaoli

    2016-09-01

    It is hypothesized that Rhizoma Coptidis (RC) alkaloids exert their hypolipidemic effects primarily by targeting the gastrointestinal tract and liver. Thus, this study was conducted to evaluate the antihyperlipidemic mechanisms of RC alkaloids (at a daily dose of 140mg/kg for 35days) in high-fat and high-cholesterol induced hyperlipidemic B6 mice. After treatment, serum lipid parameters were determined, the expression of lipid metabolism related genes and pathways such as the sterol regulatory element binding proteins (SREBPs) and bile acid signaling in mice were also investigated. Meanwhile, Illumina sequencing was used to investigate the differences in gut microbiota of B6 mice. The results indicated that RC alkaloids reduced the body weight gain and serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), total bile acids (TBA) and lipopolysaccharide of B6 mice. Liver fat deposition and epididymal adipose cell size were also deceased in therapy group. RC alkaloids feeding significantly promoted the abundance of Sporobacter termitidis, Alcaligenes faecalis, Akkermansia muciniphila in the gut of mice, whereas, the abundance of Escherichia coli, Desulfovibrio C21_c20, Parabacteroides distasonis was suppressed. The observed antihyperlipidemic effects of RC alkaloids can also be attributed to their action as agonists of FXR and TGR5, activators for SREBP2, LDLR, UCP2 and CYP7A1, inhibitors of HMGCR, TXNIP, TLR4 and JNK. Therefore, this study expands current knowledge on hypolipidemic mechanisms of RC alkaloids and presents new evidence supporting a key role for RC alkaloids as regulators of lipid homeostasis by modulation gut microbiota and hepatic lipid metabolism. PMID:27287254

  12. Improved total synthesis and biological evaluation of potent apratoxin S4 based anticancer agents with differential stability and further enhanced activity.

    Science.gov (United States)

    Chen, Qi-Yin; Liu, Yanxia; Cai, Weijing; Luesch, Hendrik

    2014-04-10

    Apratoxins are cytotoxic natural products originally isolated from marine cyanobacteria that act by preventing cotranslational translocation early in the secretory pathway to downregulate receptor levels and inhibit growth factor secretion, leading to potent antiproliferative activity. Through rational design and total synthesis of an apratoxin A/E hybrid, apratoxin S4 (1a), we have previously improved the antitumor activity and tolerability in vivo. Compound 1a and newly designed analogues apratoxins S7-S9 (1b-d), with various degrees of methylation at C34 (1b,c) or epimeric configuration at C30 (1d), were efficiently synthesized utilizing improved procedures. Optimizations have been applied to the synthesis of key intermediate aldehyde 7 and further include the application of Leighton's silanes and modifications of Kelly's methods to induce thiazoline ring formation in other crucial steps of the apratoxin synthesis. Apratoxin S9 (1d) exhibited increased activity with subnanomolar potency. Apratoxin S8 (1c) lacks the propensity to be deactivated by dehydration and showed efficacy in a human HCT116 xenograft mouse model.

  13. Total Chemical Synthesis of a Heterodimeric Interchain Bis-Lactam-Linked Peptide: Application to an Analogue of Human Insulin-Like Peptide 3

    Science.gov (United States)

    Karas, John; Shabanpoor, Fazel; Hossain, Mohammed Akhter; Wade, John D.; Scanlon, Denis B.

    2013-01-01

    Nonreducible cystine isosteres represent important peptide design elements in that they can maintain a near-native tertiary conformation of the peptide while simultaneously extending the in vitro and in vivo half-life of the biomolecule. Examples of these cystine mimics include dicarba, diselenide, thioether, triazole, and lactam bridges. Each has unique physicochemical properties that impact upon the resulting peptide conformation. Each also requires specific conditions for its formation via chemical peptide synthesis protocols. While the preparation of peptides containing two lactam bonds within a peptide is technically possible and reported by others, to date there has been no report of the chemical synthesis of a heterodimeric peptide linked by two lactam bonds. To examine the feasibility of such an assembly, judicious use of a complementary combination of amine and acid protecting groups together with nonfragment-based, total stepwise solid phase peptide synthesis led to the successful preparation of an analogue of the model peptide, insulin-like peptide 3 (INSL3), in which both of the interchain disulfide bonds were replaced with a lactam bond. An analogue containing a single disulfide-substituted interchain lactam bond was also prepared. Both INSL3 analogues retained significant cognate RXFP2 receptor binding affinity. PMID:24288548

  14. Total Chemical Synthesis of a Heterodimeric Interchain Bis-Lactam-Linked Peptide: Application to an Analogue of Human Insulin-Like Peptide 3

    Directory of Open Access Journals (Sweden)

    John Karas

    2013-01-01

    Full Text Available Nonreducible cystine isosteres represent important peptide design elements in that they can maintain a near-native tertiary conformation of the peptide while simultaneously extending the in vitro and in vivo half-life of the biomolecule. Examples of these cystine mimics include dicarba, diselenide, thioether, triazole, and lactam bridges. Each has unique physicochemical properties that impact upon the resulting peptide conformation. Each also requires specific conditions for its formation via chemical peptide synthesis protocols. While the preparation of peptides containing two lactam bonds within a peptide is technically possible and reported by others, to date there has been no report of the chemical synthesis of a heterodimeric peptide linked by two lactam bonds. To examine the feasibility of such an assembly, judicious use of a complementary combination of amine and acid protecting groups together with nonfragment-based, total stepwise solid phase peptide synthesis led to the successful preparation of an analogue of the model peptide, insulin-like peptide 3 (INSL3, in which both of the interchain disulfide bonds were replaced with a lactam bond. An analogue containing a single disulfide-substituted interchain lactam bond was also prepared. Both INSL3 analogues retained significant cognate RXFP2 receptor binding affinity.

  15. An efficient and target-oriented sample enrichment method for preparative separation of minor alkaloids by pH-zone-refining counter-current chromatography.

    Science.gov (United States)

    Feng, Rui-Hong; Hou, Jin-Jun; Zhang, Yi-Bei; Pan, Hui-Qin; Yang, Wenzhi; Qi, Peng; Yao, Shuai; Cai, Lu-Ying; Yang, Min; Jiang, Bao-Hong; Liu, Xuan; Wu, Wan-Ying; Guo, De-An

    2015-08-28

    An efficient and target-oriented sample enrichment method was established to increase the content of the minor alkaloids in crude extract by using the corresponding two-phase solvent system applied in pH-zone-refining counter-current chromatography. The enrichment and separation of seven minor indole alkaloids from Uncaria rhynchophylla (Miq.) Miq. ex Havil(UR) were selected as an example to show the advantage of this method. An optimized two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (3:7:1:9, v/v) was used in this study, where triethylamine (TEA) as the retainer and hydrochloric acid (HCl) as the eluter were added at the equimolar of 10mM. Crude alkaloids of UR dissolved in the corresponding upper phase (containing 10mM TEA) were extracted twice with lower phase (containing 10mM TEA) and lower phase (containing 10mM HCl), respectively, the second lower phase extract was subjected to pH-zone-refining CCC separation after alkalization and desalination. Finally, from 10g of crude alkaloids, 4g of refined alkaloids was obtained and the total content of seven target indole alkaloids was increased from 4.64% to 15.78%. Seven indole alkaloids, including 54mg isocorynoxeine, 21mg corynoxeine, 46mg isorhynchophylline, 35mg rhynchophylline, 65mg hirsutine, 51mg hirsuteine and 27mg geissoschizine methylether were all simultaneously separated from 2.5g of refined alkaloids, with the purity of 86.4%, 97.5%, 90.3%, 92.1%, 98.5%, 92.3%, and 92.8%, respectively. The total content and purities of the seven minor indole alkaloids were tested by HPLC and their chemical structures were elucidated by ESI-HRMS and (1)H NMR. PMID:26209189

  16. Simultaneous Screening for 45 Poisonous Alkaloids in Blood by LC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    ZHAI Jin-xiao; SHEN Min; LIU Wei

    2015-01-01

    Objective To develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) screen-ing method for 45 poisonous alkaloids in blood. Methods Identification was based on the compound’s retention time and two precursor-to-production transitions. The method involved a liquid-liquid extraction (LLE) followed by LC-MS/MS with multiple-reaction monitoring (MRM). When 1 mL of blood was ex-tracted with diethyl ether at pH=9.2 with SKF525A as the internal standard, the target compounds were an-alyzed with LC-MS/MS in the positive ionization mode. Results The target alkaloids had good linearity (r>0.995 1), both the intra-day precision and inter-day precision being less than 14.77%. The limits of detection ranged from 0.05 to 25 ng/mL in blood. Conclusion The method is selective and sensitive in detecting poisonous alkaloids with a total running time of 12 minutes; therefore it was successfully ap-plied to some actual cases of suspected alkaloids poisoning.

  17. Accumulation of Monoterpenoid Indole Alkaloids in Periwinkle Seedlings ("Catharanthus roseus") as a Model for the Study of Plant-Environment Interactions

    Science.gov (United States)

    Miranda-Ham, Maria de Lourdes; Islas-Flores, Ignacio; Vazquez-Flota, Felipe

    2007-01-01

    Alkaloids are part of the chemical arsenal designed to protect plants against an adverse environment. Therefore, their synthesis and accumulation are frequently induced in response to certain environmental conditions and are mediated by chemical signals, which are formed as the first responses to the external stimulus. A set of experiments using…

  18. Therapeutic effects of Sophora moorcroftiana alkaloids in combination with albendazole in mice experimentally infected with protoscolices of Echinococcus granulosus

    Directory of Open Access Journals (Sweden)

    X.M. Ma

    2007-10-01

    Full Text Available The objective of the present study was to determine if the combination of alkaloids from Sophora moorcroftiana seeds and albendazole might be effective in the treatment of experimental echinococcosisin female NIH mice (6 weeks old and weighing 18-20 g, N = 8 in each group infected withprotoscolices of Echinococcus granulosus. Viable protoscolices (N = 6 x 103 were cultured in vitro in 1640 medium and mortality was calculated daily. To determine the in vivo efficacy, mice were inoculated intraperitoneally with viable protoscolices and then treated once daily by gavage for three months with the alkaloids (50 mg kg-1 day-1 and albendazole (50 mg kg-1 day-1, separately and in combination (both alkaloids at 25 mg kg-1 day-1 and albendazole at 25 mg kg-1 day-1. Next, the hydatid cysts collected from the peritoneal cavity of the animals were weighed and serum IL-4, IL-2, and IgE levels were analyzed. Administration of alkaloids to cultured protoscolices showed significant dose- and time-dependent killing effects. The weight of hydatid cysts was significantly decreased upon treatment with each drug (P < 0.01, but the decrease was more prominent and the rate of hydatid cyst growth inhibition was much higher (76.1% in the group receiving the combined treatments (18.3 ± 4.6 mg. IL-4 and total IgE were decreased (939 ± 447 pg/mL and 2.03 ± 0.42 IU/mL, respectively in serum from mice treated with alkaloids and albendazole compared with the untreated control (1481 ± 619 pg/mL and 3.31 ± 0.37 IU/mL; P < 0.01. These results indicate that S. moorcroftiana alkaloids have protoscolicidal effects and the combination of alkaloids and albendazole has significant additive effects.

  19. Therapeutic effects of Sophora moorcroftiana alkaloids in combination with albendazole in mice experimentally infected with protoscolices of Echinococcus granulosus.

    Science.gov (United States)

    Ma, X M; Bao, G Sh; Wan, J M; Liao, D J; Yin, Sh F; Meng, X Q; Zhou, G K; Lu, X M; Li, H Y

    2007-10-01

    The objective of the present study was to determine if the combination of alkaloids from Sophora moorcroftiana seeds and albendazole might be effective in the treatment of experimental echinococcosisin female NIH mice (6 weeks old and weighing 18-20 g, N = 8 in each group) infected withprotoscolices of Echinococcus granulosus. Viable protoscolices (N = 6 x 10(3)) were cultured in vitro in 1640 medium and mortality was calculated daily. To determine the in vivo efficacy, mice were inoculated intraperitoneally with viable protoscolices and then treated once daily by gavage for three months with the alkaloids (50 mg kg-1 day-1) and albendazole (50 mg kg-1 day-1), separately and in combination (both alkaloids at 25 mg kg-1 day-1 and albendazole at 25 mg kg-1 day-1). Next, the hydatid cysts collected from the peritoneal cavity of the animals were weighed and serum IL-4, IL-2, and IgE levels were analyzed. Administration of alkaloids to cultured protoscolices showed significant dose- and time-dependent killing effects. The weight of hydatid cysts was significantly decreased upon treatment with each drug (P < 0.01), but the decrease was more prominent and the rate of hydatid cyst growth inhibition was much higher (76.1%) in the group receiving the combined treatments (18.3 +/- 4.6 mg). IL-4 and total IgE were decreased (939 +/- 447 pg/mL and 2.03 +/- 0.42 IU/mL, respectively) in serum from mice treated with alkaloids and albendazole compared with the untreated control (1481 +/- 619 pg/mL and 3.31 +/- 0.37 IU/mL; P < 0.01). These results indicate that S. moorcroftiana alkaloids have protoscolicidal effects and the combination of alkaloids and albendazole has significant additive effects.

  20. Alkaloids Isolated from Natural Herbs as the Anticancer Agents

    Directory of Open Access Journals (Sweden)

    Jin-Jian Lu

    2012-01-01

    Full Text Available Alkaloids are important chemical compounds that serve as a rich reservoir for drug discovery. Several alkaloids isolated from natural herbs exhibit antiproliferation and antimetastasis effects on various types of cancers both in vitro and in vivo. Alkaloids, such as camptothecin and vinblastine, have already been successfully developed into anticancer drugs. This paper focuses on the naturally derived alkaloids with prospective anticancer properties, such as berberine, evodiamine, matrine, piperine, sanguinarine, and tetrandrine, and summarizes the mechanisms of action of these compounds. Based on the information in the literature that is summarized in this paper, the use of alkaloids as anticancer agents is very promising, but more research and clinical trials are necessary before final recommendations on specific alkaloids can be made.

  1. Toxicosis by Plant Alkaloids in Humans and Animals in Colombia.

    Science.gov (United States)

    Diaz, Gonzalo J

    2015-12-11

    Due to its tropical location, chains of mountains, inter-Andean valleys, Amazon basin area, eastern plains and shores on both the Atlantic and Pacific Oceans, Colombia has many ecosystems and the second largest plant biodiversity in the world. Many plant species, both native and naturalized, are currently recognized as toxic for both animals and humans, and some of them are known to cause their toxic effects due to their alkaloid content. Among these, there are plants containing the hepatotoxic pyrrolizidine alkaloids, neurotoxins such as the indolizidine alkaloid swainsonine and the piperidine alkaloids coniine and γ-coniceine and tropane alkaloids. Unfortunately, the research in toxic plants in Colombia is not nearly proportional to its plant biodiversity and the scientific information available is only very scarce. The present review aims at summarizing the scarce information about plant alkaloid toxicosis in animals and humans in Colombia.

  2. Toxicosis by Plant Alkaloids in Humans and Animals in Colombia

    Directory of Open Access Journals (Sweden)

    Gonzalo J. Diaz

    2015-12-01

    Full Text Available Due to its tropical location, chains of mountains, inter-Andean valleys, Amazon basin area, eastern plains and shores on both the Atlantic and Pacific Oceans, Colombia has many ecosystems and the second largest plant biodiversity in the world. Many plant species, both native and naturalized, are currently recognized as toxic for both animals and humans, and some of them are known to cause their toxic effects due to their alkaloid content. Among these, there are plants containing the hepatotoxic pyrrolizidine alkaloids, neurotoxins such as the indolizidine alkaloid swainsonine and the piperidine alkaloids coniine and γ-coniceine and tropane alkaloids. Unfortunately, the research in toxic plants in Colombia is not nearly proportional to its plant biodiversity and the scientific information available is only very scarce. The present review aims at summarizing the scarce information about plant alkaloid toxicosis in animals and humans in Colombia.

  3. Antimicrobial alkaloids from Zanthoxylum tetraspermum and caudatum.

    Science.gov (United States)

    Nissanka, A P; Karunaratne, V; Bandara, B M; Kumar, V; Nakanishi, T; Nishi, M; Inada, A; Tillekeratne, L M; Wijesundara, D S; Gunatilaka, A A

    2001-04-01

    Two benzophenanthrene alkaloids, 8-acetonyldihydronitidine and 8-acetonyldihydroavicine were isolated from Zanthoxylum tetraspermum stem bark along with liriodenine, sesamin, lichexanthone and (+)-piperitol-gamma,gamma-dimethylallylether. The species endemic to Sri Lanka, Z. caudatum, contained sesamin, savinin, liriodenine, decarine and 8-O-desmethyl-N-nornitidine. 8-Acetonyldihydronitidine and 8-acetonyldihydroavicine showed significant antibacterial activity while the former along with liriodenine was strongly antifungal. Savinin exhibited potent spermicidal activity. Both savinin and sesamin exhibited significant insecticidal activity. PMID:11324918

  4. A new alkaloid from Solanum cathayanum

    Institute of Scientific and Technical Information of China (English)

    Fan Cheng; Xiang Li; Jun Zhi Wang

    2008-01-01

    A new alkaloid compound I was obtained from Solanum cathayanum, a folk medicine of Hubei Province, together with a knownalkaloid, orotic acid ethyl ester. On the basis of spectroscopic data and chemical methods, I was identified as 8-hydroxy-3-methoxy-5H-pyrido[2,1-c]pyrazin-5-one. Compound 1 can inhibit the production of NO in peritoneal macrophage of mice induced with LPS.The content of NO was determined by enzyme methods.

  5. Potential antimalarial activity of indole alkaloids

    OpenAIRE

    Frederich, Michel; Tits, Monique; Angenot, Luc

    2008-01-01

    New antimalarial treatments are now urgently required, following the emergence of resistance to the most used drugs. Natural products contribute greatly to the therapeutic arsenal in this area, including artemisinin and quinine (and atovaquone, semi-synthetic). Among the natural products, indole alkaloids represent an interesting class of compounds. Screening carried out to date has revealed several substances active in vitro under the micromolar range and with a good selectivity index. This ...

  6. Pyrrolizidine alkaloids and diterpenes from Villasenoria orcuttii

    Energy Technology Data Exchange (ETDEWEB)

    Arciniegas, Amira; Perez-Castorena, Ana L.; Gonzalez, Karina; Vivar, Alfonso Romo de, E-mail: alperezc@unam.mx [Instituto de Quimica, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Coyoacan, DF (Mexico); Reyes-Lezama, Marisol [Centro Conjunto de Investigacion en Quimica Sustentable, Universidad Autonoma del Estado de Mexico-Universidad Nacional Autonoma de Mexico (UAEM-UNAM), Carretera Toluca-Atlacomulco, Estado de Mexico (Mexico); Villasenor, Jose Luis [Instituto de Biologia, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Coyoacan, DF, (Mexico)

    2013-07-15

    The chemical study of Villasenoria orcuttii, the only species of the genus Villasenoria, afforded three acyclic diterpenes, two of them described for the first time. Two pyrrolizidine alkaloids, florosenine and floridanine, among other known compounds were also isolated. The absolute configuration of floridanine was determined by X-ray analysis using anomalous dispersion with Cu K{sub {alpha}} radiation, and its {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR) data were corrected. (author)

  7. A new diketopiperazine alkaloid from Aspergillus oryzae.

    Science.gov (United States)

    Shaaban, Mohamed; El-Metwally, Mohammad Magdy; Nasr, Hamdi

    2014-01-01

    Investigation of bioactive secondary metabolites from terrestrial Aspergillus oryzae sp. MMAO1 using M2 medium afforded a new diketopiperazine alkaloid, 7,9-dihydroxy-3-(1H-indol-3-ylmethyl)-8-methoxy-2,3,11,11a-tetrahydro-6H-pyrazino[1,2-b]isoquinoline-1,4-dione (1a), containing the unusual amino acid L-6,8-dihydroxy-7-methoxyphenylalanine. This was co-isolated with ditryptophenaline (2), cyclo-(Tryp,Tyr) (4), cyclo-(Pro,Val), α-cyclopiazonic acid (3), kojic acid and uridine. Re-cultivation of the fungal strain on Dox medium led to the production of bisdethio(bismethylthio)gliotoxin (5), pseurotin A (6) along with linoleic acid, α-cyclopiazonic acid (3) and kojic acid. The chemical structure of the new diketopiperazine alkaloid including the relative configuration was determined by 1D and 2D NMR spectroscopy and HR-ESI-MS spectrometry, and by comparison with the related literature. The new alkaloid (1a) showed no antimicrobial activity or cytotoxicity against brine shrimps.

  8. Novel Microtubule-Targeting 7-Deazahypoxanthines Derived from Marine Alkaloid Rigidins with Potent in Vitro and in Vivo Anticancer Activities.

    Science.gov (United States)

    Medellin, Derek C; Zhou, Qiong; Scott, Robert; Hill, R Matthew; Frail, Sarah K; Dasari, Ramesh; Ontiveros, Steven J; Pelly, Stephen C; van Otterlo, Willem A L; Betancourt, Tania; Shuster, Charles B; Hamel, Ernest; Bai, Ruoli; LaBarbera, Daniel V; Rogelj, Snezna; Frolova, Liliya V; Kornienko, Alexander

    2016-01-14

    Docking studies of tubulin-targeting C2-substituted 7-deazahypoxanthine analogues of marine alkaloid rigidins led to the design and synthesis of compounds containing linear C2-substituents. The C2-alkynyl analogue was found to have double- to single-digit nanomolar antiproliferative IC50 values and showed statistically significant tumor size reduction in a colon cancer mouse model at nontoxic concentrations. These results provide impetus and further guidance for the development of these rigidin analogues as anticancer agents. PMID:26641132

  9. Two New Alkaloids from Roots of Stemona tuberosa

    Directory of Open Access Journals (Sweden)

    Ligen Lin

    2014-07-01

    Full Text Available The roots of Stemona tuberosa ha ve been used as an antitussive and insecticide remedy for thousands of years. On the chemical investigation of the roots of S . tuberosa , two new tuberostemonine-type alkaloids, epoxy-tuberostemonol (1, and neotuberostemoenone (2, together with a known alkaloid, n eotuberostemonine, were isolated and identified. The structures of new alkaloids were established on the basis of 1D and 2D NMR and other spectroscopic analyses.

  10. Initial Studies on Alkaloids from Lombok Medicinal Plants

    Directory of Open Access Journals (Sweden)

    John B. Bremner

    2001-01-01

    Full Text Available Initial investigation of medicinal plants from Lombok has resulted in the collection of 100 plant species predicted to have antimicrobial, including antimalarial, properties according to local medicinal uses. These plants represent 49 families and 80 genera; 23% of the plants tested positively for alkaloids. Among the plants testing positive, five have been selected for further investigation involving structure elucidation and antimicrobial testing on the extracted alkaloids. Initial work on structural elucidation of some of the alkaloids is reported briefly.

  11. A new monoterpenoid oxindole alkaloid from Hamelia patens micropropagated plantlets.

    Science.gov (United States)

    Paniagua-Vega, David; Cerda-García-Rojas, Carlos M; Ponce-Noyola, Teresa; Ramos-Valdivia, Ana C

    2012-11-01

    Chemical studies on Hamelia patens (Rubiaceae) micropropagated plantlets allowed production of a new monoterpenoid oxindole alkaloid, named (-)-hameline (7), together with eight known alkaloids, tetrahydroalstonine (1), aricine (2), pteropodine (3), isopteropodine (4), uncarine F (5), speciophylline (6), palmirine (8), and rumberine (9). The structure of the new alkaloid was assigned on the basis of 1D and 2D NMR spectroscopy, mass spectrometry, and molecular modeling.

  12. Total synthesis of pinnatoxins A and G and revision of the mode of action of pinnatoxin A.

    Science.gov (United States)

    Araoz, Romulo; Servent, Denis; Molgó, Jordi; Iorga, Bogdan I; Fruchart-Gaillard, Carole; Benoit, Evelyne; Gu, Zhenhua; Stivala, Craig; Zakarian, Armen

    2011-07-13

    Pinnatoxins belong to an emerging class of potent marine toxins of the cyclic imine group. Detailed studies of their biological effects have been impeded by unavailability of the complex natural product from natural sources. This work describes the development of a robust, scalable synthetic sequence relying on a convergent strategy that delivered a sufficient amount of the toxin for detailed biological studies and its commercialization for use by other research groups and regulatory agencies. A central transformation in the synthesis is the highly diastereoselective Ireland-Claisen rearrangement of a complex α,α-disubstituted allylic ester based on a unique mode for stereoselective enolization through a chirality match between the substrate and the lithium amide base. With synthetic pinnatoxin A, a detailed study has been performed that provides conclusive evidence for its mode of action as a potent inhibitor of nicotinic acetylcholine receptors selective for the human neuronal α7 subtype. The comprehensive electrophysiological, biochemical, and computational studies support the view that the spiroimine subunit of pinnatoxins is critical for blocking nicotinic acetylcholine receptor subtypes, as evidenced by analyzing the effect of a synthetic analogue of pinnatoxin A containing an open form of the imine ring. Our studies have paved the way for the production of certified standards to be used for mass-spectrometric determination of these toxins in marine matrices and for the development of tests to detect these toxins in contaminated shellfish. PMID:21644584

  13. Evaluation of antimicrobial activity of alkaloids of Terminalia chebula Retz. against some multidrug-resistant microorganisms

    Directory of Open Access Journals (Sweden)

    Geeta Singh

    2012-01-01

    activity against nine bacteria (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, Bacillus subtilis, Raoultella planticola, Enterobacter aerogens, Agrobacterium tumefaciens, and Klebsiella pneumoniae and two fungi (Aspergillus flavus and Aspergillus niger and one yeast (Candida albicans. Minimum inhibitory concentration, Minimum bactericidal/fungicidal concentration, and Total activity of the extracts, against each sensitive test pathogen, were also evaluated. Alkaloids from all plant parts showed good antimicrobial activity against almost all the test microorganisms except A. niger, against which, none of the tested extracts showed activity. The largest zone of inhibition (IZ 20.75 mm was observed against P. aeruginosa. The total activity of the leaf alkaloid was found to be the same and the highest (256.41ml/g was against E. aerogens and A. tumefaciens.

  14. Binding Parameters of Alkaloids Berberine and Sanguinarine with DNA

    CERN Document Server

    Gumenyuk, V G; Kutovyy, S Yu; Yashchuk, V M; Zaika, L A

    2012-01-01

    We study the interaction of berberine and sanguinarine (plant alkaloids) with DNA in aqueous solutions, by using optical spectroscopy methods (absorption and fluorescence). The dependencies of alkaloid spectral characteristics on the concentration ratio N/c between the DNA base pairs and alkaloid molecules in the solutions are considered, and the manifestations of the alkaloid-DNA binding are revealed. The character of binding is found to depend on N/c. The parameters of the binding of berberine and sanguinarine with DNA are determined, by using the modified Scatchard and McGhee-von Hippel equations

  15. Evaluation of Biosynthetic Pathway and Engineered Biosynthesis of Alkaloids.

    Science.gov (United States)

    Kishimoto, Shinji; Sato, Michio; Tsunematsu, Yuta; Watanabe, Kenji

    2016-01-01

    Varieties of alkaloids are known to be produced by various organisms, including bacteria, fungi and plants, as secondary metabolites that exhibit useful bioactivities. However, understanding of how those metabolites are biosynthesized still remains limited, because most of these compounds are isolated from plants and at a trace level of production. In this review, we focus on recent efforts in identifying the genes responsible for the biosynthesis of those nitrogen-containing natural products and elucidating the mechanisms involved in the biosynthetic processes. The alkaloids discussed in this review are ditryptophenaline (dimeric diketopiperazine alkaloid), saframycin (tetrahydroisoquinoline alkaloid), strictosidine (monoterpene indole alkaloid), ergotamine (ergot alkaloid) and opiates (benzylisoquinoline and morphinan alkaloid). This review also discusses the engineered biosynthesis of these compounds, primarily through heterologous reconstitution of target biosynthetic pathways in suitable hosts, such as Escherichia coli, Saccharomyces cerevisiae and Aspergillus nidulans. Those heterologous biosynthetic systems can be used to confirm the functions of the isolated genes, economically scale up the production of the alkaloids for commercial distributions and engineer the biosynthetic pathways to produce valuable analogs of the alkaloids. In particular, extensive involvement of oxidation reactions catalyzed by oxidoreductases, such as cytochrome P450s, during the secondary metabolite biosynthesis is discussed in details. PMID:27548127

  16. Evaluation of Biosynthetic Pathway and Engineered Biosynthesis of Alkaloids

    Directory of Open Access Journals (Sweden)

    Shinji Kishimoto

    2016-08-01

    Full Text Available Varieties of alkaloids are known to be produced by various organisms, including bacteria, fungi and plants, as secondary metabolites that exhibit useful bioactivities. However, understanding of how those metabolites are biosynthesized still remains limited, because most of these compounds are isolated from plants and at a trace level of production. In this review, we focus on recent efforts in identifying the genes responsible for the biosynthesis of those nitrogen-containing natural products and elucidating the mechanisms involved in the biosynthetic processes. The alkaloids discussed in this review are ditryptophenaline (dimeric diketopiperazine alkaloid, saframycin (tetrahydroisoquinoline alkaloid, strictosidine (monoterpene indole alkaloid, ergotamine (ergot alkaloid and opiates (benzylisoquinoline and morphinan alkaloid. This review also discusses the engineered biosynthesis of these compounds, primarily through heterologous reconstitution of target biosynthetic pathways in suitable hosts, such as Escherichia coli, Saccharomyces cerevisiae and Aspergillus nidulans. Those heterologous biosynthetic systems can be used to confirm the functions of the isolated genes, economically scale up the production of the alkaloids for commercial distributions and engineer the biosynthetic pathways to produce valuable analogs of the alkaloids. In particular, extensive involvement of oxidation reactions catalyzed by oxidoreductases, such as cytochrome P450s, during the secondary metabolite biosynthesis is discussed in details.

  17. Evaluation of antibiotic potential of alkaloids of Tribulus terrestris L. against some pathogenic microorganisms

    Directory of Open Access Journals (Sweden)

    Alka Jindal

    2013-01-01

    Full Text Available Context: Antibiotic resistance has become a global concern. There has been an increasing incidence of multiple resistances in human pathogenic microorganisms in recent years, largely due to indiscriminate use of commercial antimicrobial drugs commonly employed in the treatment of infectious diseases. Tribulus terrestris (Family: Zygophyllaceae is a well-known medicinal plant and has been used world-wide for the treatment of infectious diseases. Alkaloids are group of naturally occurring chemical compounds, which are known to have antimicrobial properties. Aim: The present study is designed to evaluate the antimicrobial potential of alkaloids of T. terrestris L. Materials and Methods: Alkaloids extracted from different parts (root, stem, leaf and fruits of T. terrestris were screened by Disc diffusion assay against three bacterial strains: gram positive (Staphylococcus aureus, gram negative (Escherichia coli and Proteus mirabilis and two fungal strains: Aspergillus flavus and Aspergillus niger. Minimum inhibitory concentration of the extracts was evaluated by micro broth dilution method while minimum bactericidal/fungicidal concentration was determined by sub culturing the relevant samples. Total activity of the extracts against each sensitive test pathogens was also calculated. Statistical Analysis: Mean value and standard error mean were calculated for the results of disc diffusion assay and data were analysed by one-way analysis of variance and P values were considered significant at P < 0.05. Results: The alkaloid extracts of T. terrestris showed significant antibacterial potential as all test extracts were found active against both the gram positive and negative bacteria, but were inactive against the tested fungi. Conclusion: The present study indicates the broad spectrum antibacterial potential of the alkaloids of T. terrestris, hence may be exploited for future antibacterial drugs.

  18. Synthesis of bridged diketopiperazines by using the persistent radical effect and a formal synthesis of bicyclomycin.

    Science.gov (United States)

    Amatov, Tynchtyk; Pohl, Radek; Císařová, Ivana; Jahn, Ullrich

    2015-10-01

    A conceptually new and unified approach to diverse bridged diketopiperazines (DKPs) with widely variable ring sizes was developed by taking advantage of the persistent radical effect. This method enables synthesis of the core structures of bridged DKP alkaloids and was applied to a formal synthesis of the antibiotic bicyclomycin.

  19. Total synthesis and biological evaluation of a series of macrocyclic hybrids and analogues of the antimitotic natural products dictyostatin, discodermolide, and taxol.

    Science.gov (United States)

    Paterson, Ian; Naylor, Guy J; Gardner, Nicola M; Guzmán, Esther; Wright, Amy E

    2011-02-01

    The design, synthesis, and biological evaluation of a series of hybrids and analogues of the microtubule-stabilizing anticancer agents dictyostatin, discodermolide, and taxol is described. A 22-membered macrolide scaffold was prepared by adapting earlier synthetic routes directed towards dictyostatin and discodermolide, taking advantage of the distinctive structural and stereochemical similarities between these two polyketide-derived marine natural products. Initial endeavors towards accessing novel discodermolide/dictyostatin hybrids led to the adoption of a late-stage diversification strategy and the construction of a small library of methyl-ether derivatives, along with the first triple hybrids bearing the side-chain of taxol or taxotere attached through an ester linkage. Biological assays of the anti-proliferative activity of these compounds in a series of human cancer cell lines, including the taxol-resistant NCI/ADR-Res cell line, allowed the proposal of various structure-activity relationships. This led to the identification of a potent macrocyclic discodermolide/dictyostatin hybrid 12 and its C9 methoxy derivative 38, accessible by an efficient total synthesis and with a similar biological profile to dictyostatin.

  20. Synthesis, structure and total conductivity of A-site doped LaTiO{sub 3−δ} perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Bradha, M. [Nanotech Research Facility, PSG Institute of Advanced Studies, Coimbatore 641 004, TN (India); Hussain, S.; Chakravarty, Sujay [UGC-DAE CSR, Kalpakkam Node, Kokilamedu 603 104, TN (India); Amarendra, G. [UGC-DAE CSR, Kalpakkam Node, Kokilamedu 603 104, TN (India); Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, TN (India); Ashok, Anuradha, E-mail: anu.machina@gmail.com [Nanotech Research Facility, PSG Institute of Advanced Studies, Coimbatore 641 004, TN (India)

    2015-03-25

    Highlights: • A-site divalent alkaline earth metal doped LaTiO{sub 3−δ} perovskites were synthesised by sol–gel method. • Structural studies revealed no change in crystal symmetry but change in cell dimensions after doping. • After doping divalent cations in A-site, an enhancement in total conductivity was observed in LaTiO{sub 3−δ}. • Temperature dependent electrical property was observed in all synthesised perovskites. - Abstract: Oxygen deficient perovskites LaTiO{sub 3−δ} and La{sub 0.8}A{sub 0.2}TiO{sub 3−δ} (A = Ba, Sr, Ca) were synthesized by sol–gel method. The effect of divalent dopants on microstructure is investigated in detail using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The oxidation states of La{sup 3+} and Ti{sup 3+} ions have been deduced using X-ray Photoelectron Spectroscopy (XPS). Impedance spectroscopy was used to analyze the total conductivity, an increase in conductivity was observed after doping in the A-site with divalent cations Ba, Ca and Sr. Among the investigated perovskites La{sub 0.8}Ca{sub 0.2}TiO{sub 3−δ} exhibited the maximum conductivity of 1.22 × 10{sup −2} S/cm in air atmosphere at 650 °C.

  1. Development of a third-generation total synthesis of (+)-discodermolide: an expedient Still-Gennari-type fragment coupling utilizing an advanced beta-ketophosphonate.

    Science.gov (United States)

    Paterson, Ian; Lyothier, Isabelle

    2005-07-01

    [structure: see text] A novel total synthesis of the complex polyketide discodermolide, a promising anticancer agent of marine sponge origin, has been completed in 11.1% overall yield over 21 linear steps. This third-generation approach features an unprecedented Still-Gennari-type HWE olefination reaction between advanced C1-C8 beta-ketophosphonate 61 and C9-C24 aldehyde 7, introducing the (8Z)-alkene with 10:1 selectivity. The stereotetrad found in the C1-C8 subunit 61 was established via a highly diastereoselective boron-mediated aldol reaction/in situ reduction between ketone (S)-8 and 3-benzyloxypropanal. The (7S)-configuration was installed by the reduction of enone 73 with K-Selectride.

  2. Autoradiographic studies on mucilage synthesis in Chara vulgaris antheridium with the use of 3H-fucose in total darkness and light

    International Nuclear Information System (INIS)

    Autoradiographic studies with 3H-fucose have shown that this precursor of polysaccharide compounds is incorporated into manubria and antheridial mucilage of Chara vulgaris both in the light and in the darkness. The dynamic of this process is lower in total darkness. The decrease in overall labelling of antheridium (manubria an mucilage) reflects secondary metabolic changes both in proliferative phase and in spermiogenesis. The pulse (2 and 5 min) incubations with the isotope confirm the intensive mucilage translocation which at later developmental stages is more dynamic than at earlier ones. It can explain previously observed decrease in manubria radioactivity at later stages after long (40 min) incubation, because PAS-positive polysaccharide synthesis is simultaneous with their fast translocation to the antheridial space. The present and previous autoradiographic and cytophotometric data taken altogether confirm the assumption about a nutritive role of mucilage filling Chara antheridium during the process of spermatogenesis. (author). 19 refs, 7 figs

  3. Autoradiographic studies on mucilage synthesis in Chara vulgaris antheridium with the use of {sup 3}H-fucose in total darkness and light

    Energy Technology Data Exchange (ETDEWEB)

    Gosek, A. [Lodz Univ. (Poland)

    1996-12-31

    Autoradiographic studies with {sup 3}H-fucose have shown that this precursor of polysaccharide compounds is incorporated into manubria and antheridial mucilage of Chara vulgaris both in the light and in the darkness. The dynamic of this process is lower in total darkness. The decrease in overall labelling of antheridium (manubria an mucilage) reflects secondary metabolic changes both in proliferative phase and in spermiogenesis. The pulse (2 and 5 min) incubations with the isotope confirm the intensive mucilage translocation which at later developmental stages is more dynamic than at earlier ones. It can explain previously observed decrease in manubria radioactivity at later stages after long (40 min) incubation, because PAS-positive polysaccharide synthesis is simultaneous with their fast translocation to the antheridial space. The present and previous autoradiographic and cytophotometric data taken altogether confirm the assumption about a nutritive role of mucilage filling Chara antheridium during the process of spermatogenesis. (author). 19 refs, 7 figs.

  4. Total replacement of corn by mesquite pod meal considering nutritional value, performance, feeding behavior, nitrogen balance, and microbial protein synthesis of Holstein-Zebu crossbred dairy steers.

    Science.gov (United States)

    de Oliveira Moraes, Gláucia Sabrine; de Souza, Evaristo Jorge Oliveira; Véras, Antonia Sherlânea Chaves; de Paula Almeida, Marina; da Cunha, Márcio Vieira; Torres, Thaysa Rodrigues; da Silva, Camila Sousa; Pereira, Gerfesson Felipe Cavalcanti

    2016-10-01

    The objective of the present study to assess the effects of mesquite pod addition replacing corn (0, 250, 500, 750, and 1000 g/kg in the dry matter basis) on nutrient intake, animal performance, feeding behavior, nutrient digestibility, nitrogen balance, and microbial protein synthesis. Twenty-five Holstein-Zebu crossbred dairy steers at 219 ± 22 kg initial body weight and 18 months of age were used. The experiment lasted 84 days, divided into three periods of 28 days. A completely randomized design was used, and data were submitted to analysis using PROC GLM for analysis of variance and PROC REG for regression analysis using the software Statistical Analysis Systems version 9.1. Experimental diets were composed of Tifton 85 hay, soybean meal, ground corn, mesquite pod meal, and mineral salt. Samples of food offered were collected during the last 3 days of each period, and the leftovers were collected daily, with samples bulked per week. At the end of each 28-day period, the remaining animals were weighed to determine total weight gain and average daily gain. The assessment of behavioral patterns was performed through instantaneous scans in 5-min intervals for three consecutive 12-h days. A single urine sample from each animal was collected on the last day of each collection period at about 4 h after the first feeding. The replacement of corn by mesquite pod meal did not significantly influence treatments regarding nutrients intake, animal performance, and feeding behavior. Retained and consumed nitrogen ratio did not statistically differ between replacement levels. Likewise, there were no statistical differences regarding microbial protein synthesis and efficiency between replacement levels. Mesquite pod meal can be used in Holstein-Zebu crossbred dairy steers' diet with total corn replacement. PMID:27387896

  5. Studies of interaction between two alkaloids and double helix DNA

    International Nuclear Information System (INIS)

    This article presents the study on the interaction of two alkaloids (matrine and evodiamine) and hs-DNA by absorption, fluorescence, circular dichroism (CD), DNA melting and viscosity experiments. The spectroscopic studies suggested that two alkaloids can bind to DNA through an intercalative mode. The viscosity measurement and thermal denaturation also indicated that two alkaloids can intercalate to DNA. The binding constants (KA) and the number of binding sites (n) were determined. At the same time, some significant thermodynamic parameters of the binding of the alkaloids to DNA were obtained. Competitive binding studies revealed that alkaloids had an effect on ethidium bromide (EB) bound DNA. In addition, it was also proved that the fluorescence quenching was influenced by ionic strength. - Highlights: • Interaction between two alkaloids and DNA is studied by spectral methods. • The binding constant and the binding sites between two alkaloids and DNA are obtained. • There are a classical intercalative mode between alkaloids and DNA. • The binding of matrine with DNA is weaker than that of evodiamine. • It is important for us to understand the alkaloids–DNA interactions at a molecular level

  6. Pyrrolizidine alkaloids from Bulgarian species of the genus Senecio

    Directory of Open Access Journals (Sweden)

    NADEZHDA KOSTOVA

    2006-12-01

    Full Text Available Nine Bulgarian species from the genus Senecio were studied phytochemically and/or by GC-MS analysis. Senecivernine-N-oxide was isolated and identified by spectral data for the first time. Different types of pyrrolizidine alkaloids were tested for cytotoxicity on murine lymphocytes. At a concentration of 100 µg/ml, the alkaloid retroisosenine showed immunosuppressive effect.

  7. Galanthindole: a new indole alkaloid from Galanthus plicatus ssp. byzantinus.

    Science.gov (United States)

    Unver, Nehir; Kaya, G Irem; Werner, Christa; Verpoorte, Robert; Gözler, Belkis

    2003-09-01

    A new indole alkaloid, galanthindole, was isolated from Galanthus plicatus ssp. byzantinus (Amaryllidaceae), a plant native to northwestern Turkey. Incorporating a non-fused indole ring, galanthindole may represent the prototype of a new subgroup of the Amaryllidaceae alkaloids. Two other bases, (+)-11-hydroxyvittatine and hordenine, are also reported from the same plant.

  8. Two New Norditerpenoid Alkaloids from Aconitum spicatum Stapf

    Institute of Scientific and Technical Information of China (English)

    Li Ming GAO; Xiao Mei WEI; Li YANG

    2005-01-01

    Two new norditerpenoid alkaloids, spicatine A (1) and spicatine B (2) were isolated from the root of Aconitum spicatum. The new compounds were deduced on the basis of their spectral data (IR, HREIMS, EIMS, 1D, 2D-NMR). This is the first whole report on the isolation of diterpenoid alkaloids from the A. spicatum Stapf.

  9. Studies of interaction between two alkaloids and double helix DNA

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yantao [Key Laboratory of Preparation and Applications of Environmentally Friendly Materials (Jilin Normal University), Ministry of Education China, Siping 136000 (China); College of Chemistry, Jilin Normal University, Siping 136000 (China); Peng, Tingting [College of Chemistry, Jilin Normal University, Siping 136000 (China); College of Chemistry, Baicheng Normal University, Baicheng, 130032 (China); Zhao, Lei [Siping Institute for Food and Drug Control, Siping 136000 (China); Jiang, Dayu [Key Laboratory of Preparation and Applications of Environmentally Friendly Materials (Jilin Normal University), Ministry of Education China, Siping 136000 (China); College of Chemistry, Jilin Normal University, Siping 136000 (China); Cui, Yuncheng, E-mail: 1979yanzi@163.com [Key Laboratory of Preparation and Applications of Environmentally Friendly Materials (Jilin Normal University), Ministry of Education China, Siping 136000 (China); College of Chemistry, Jilin Normal University, Siping 136000 (China)

    2014-12-15

    This article presents the study on the interaction of two alkaloids (matrine and evodiamine) and hs-DNA by absorption, fluorescence, circular dichroism (CD), DNA melting and viscosity experiments. The spectroscopic studies suggested that two alkaloids can bind to DNA through an intercalative mode. The viscosity measurement and thermal denaturation also indicated that two alkaloids can intercalate to DNA. The binding constants (K{sub A}) and the number of binding sites (n) were determined. At the same time, some significant thermodynamic parameters of the binding of the alkaloids to DNA were obtained. Competitive binding studies revealed that alkaloids had an effect on ethidium bromide (EB) bound DNA. In addition, it was also proved that the fluorescence quenching was influenced by ionic strength. - Highlights: • Interaction between two alkaloids and DNA is studied by spectral methods. • The binding constant and the binding sites between two alkaloids and DNA are obtained. • There are a classical intercalative mode between alkaloids and DNA. • The binding of matrine with DNA is weaker than that of evodiamine. • It is important for us to understand the alkaloids–DNA interactions at a molecular level.

  10. ALKALOIDS OF SOME EUROPEAN AND MACARONESIAN SEDOIDEAE AND SEMPERVIVOIDEAE (CRASSULACEAE)

    NARCIS (Netherlands)

    STEVENS, JF; THART, H; HENDRIKS, H; MALINGRE, TM

    1992-01-01

    Some 22 pyrrolidine and piperdine alkaloids were detected in the leafy parts of Sedum acre, S. aetnense, S. anglicum, S. brissemoreti, S. farinosum, S. fusiforme, S. lancerottense, S. melanantherum, and S. nudum. In addition to the alkaloids known from S. acre, 1-(2-pyrrolidyl)-propan-2-one and 2-mo

  11. Extraction of alkaloids for NMR-based profiling

    DEFF Research Database (Denmark)

    Yilmaz, Ali; Nyberg, Nils; Jaroszewski, Jerzy W.

    2012-01-01

    of the well-known cinchona alkaloids quinine, cinchonine and cinchonidine without any apparent clustering. Signals from analogues were detected but not in substantial amounts. The main variation was related to the absolute amounts of extracted alkaloids, which was attributed to the evolution of the Cinchona...

  12. New monoterpenoid alkaloids from the aerial parts of Uncaria hirsuta.

    Science.gov (United States)

    Jia, Jun-Feng; Zhang, Yuan; Huang, Xiao-Jun; Zhang, Sheng-Yuan; Tian, Hai-Yan; Wang, Lei; Ye, Wen-Cai

    2014-01-01

    To investigate the chemical constituents of medicinal plant Uncaria hirsuta, three new monoterpenoid alkaloids, named hirsutanines A-C (1-3), were isolated. Their structures with absolute configurations were elucidated by means of NMR, X-ray diffraction and CD analysis. Compound 3 was the first dimeric monoterpenoid alkaloid obtained from genus Uncaria. PMID:24684175

  13. Effects of Ergot Alkaloids on Bovine Sperm Motility In Vitro

    Science.gov (United States)

    Ergot alkaloids are synthesized by endophyte-infected (Neotyphodium coenophialum) tall fescue (Lolium arundinaceum (Schreb.) S.J. Darbyshire). Our objective was to determine direct effects of ergot alkaloids (ergotamine, dihydroergotamine and ergonovine) on the motility of bovine spermatozoa in vit...

  14. Antioxidant activities of alkaloid extracts of two Algerian species of Fumaria : Fumaria capreolata and Fumaria bastardii

    Directory of Open Access Journals (Sweden)

    Fadila Maiza-Benabdesselam

    2007-11-01

    Full Text Available The antioxidant activities of the alkaloid extracts of Fumaria capreolata (L. and Fumaria bastardii (L. were determined by measuring their reducing power, their ability to inhibit linoleic acid peroxidation, and 2,2-diphenyl-β-picrylhydrazyl (DPPH radical scavenging activities. Total quinolizidine alkaloid contents were found to be 426 mg/100 g (F.capreolata and 521 mg/100g (F.bastardii. Both plant extracts exhibited strong total antioxidant activity, however, extract of F.bastardii was more potent then F.capreolata. Concentrations of 100, 300, and 500µg mL -1 showed 42, 55, 65 and 48.3, 60, and 67.8 % inhibition of lipid peroxidation of linoleic acid emulsion, for F.capreolata and F.bastardii extracts, respectively. On the other hand, 500µg mL -1 of the standard antioxidant butylated hydroxyianisole (BHA, quercetine, and caffeine exhibited 80, 56.2, and 64.3% inhibition of lipid peroxidation, respectively. In addition, the both extracts had effective reducing power, DPPH free radical scavenging activity at 250 and 50 µg mL -1. The isoquinoline alkaloids, stylopine, protopine, fumaritine, fumaricine, fumarophycine, fumariline, fumarofine were determined by GC-MS from the aerial parts of F. capreolata and F. bastardii.

  15. Effect of a 60-day oral gavage of a crude alkaloid extract from Chromolaena odorata leaves on hormonal and spermatogenic indices of male rats.

    Science.gov (United States)

    Yakubu, Musa T

    2012-01-01

    The present study was aimed at investigating the effects of the crude alkaloids isolated from Chromolaena odorata leaves on the hormonal and spermatogenic indices of male rats. The alkaloids obtained from C odorata leaves using standard methods were administered to male rats for 60 days at the doses of 250, 500, and 1000 mg/kg body weight. Thin-layer chromatographic analysis of the alkaloid mixture produced 8 spots, 3 of which were alkaloids with R(f) values of 0.41, 0.49, and 0.55 as confirmed by the formation of orange color and creamy precipitates with both Dragendorff and Mayer reagents, respectively. The alkaloids were represented in the extract by a yield of 20.28 g, corresponding to a percentage yield of 90.05% of the total extract of 22.52 g. The final body weights of both the control and alkaloid-treated animals increased significantly (P odorata leaves may be due to nonavailability or deprivation of testosterone to the target organ. This lack of testosterone may have consequential effects on the reproductive process of the male rat. PMID:22653963

  16. Neurotoxic Alkaloids: Saxitoxin and Its Analogs

    Directory of Open Access Journals (Sweden)

    Troco K. Mihali

    2010-07-01

    Full Text Available Saxitoxin (STX and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs. PSTs are the causative agents of paralytic shellfish poisoning (PSP and are mostly associated with marine dinoflagellates (eukaryotes and freshwater cyanobacteria (prokaryotes, which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified in several cyanobacterial genera including Anabaena, Cylindrospermopsis, Aphanizomenon Planktothrix and Lyngbya. STX and its analogs can be structurally classified into several classes such as non-sulfated, mono-sulfated, di-sulfated, decarbamoylated and the recently discovered hydrophobic analogs—each with varying levels of toxicity. Biotransformation of the PSTs into other PST analogs has been identified within marine invertebrates, humans and bacteria. An improved understanding of PST transformation into less toxic analogs and degradation, both chemically or enzymatically, will be important for the development of methods for the detoxification of contaminated water supplies and of shellfish destined for consumption. Some PSTs also have demonstrated pharmaceutical potential as a long-term anesthetic in the treatment of anal fissures and for chronic tension-type headache. The recent elucidation of the saxitoxin biosynthetic gene cluster in cyanobacteria and the identification of new PST analogs will present opportunities to further explore the pharmaceutical potential of these intriguing alkaloids.

  17. Influence of Nonpolar Substances on the Extraction Efficiency of Six Alkaloids in Zoagumhwan Investigated by Ultra Performance Liquid Chromatography and Photodiode Array Detection

    Directory of Open Access Journals (Sweden)

    Shijing Liu

    2012-11-01

    Full Text Available A reverse phase ultra performance liquid chromatography and photodiode array (UPLC-PDA detection method was established for the determination of six alkaloids in Zoagumhwan (ZGW, and further for investigating the influence of nonpolar substances on the extraction efficiency of these alkaloids. The method was based on a BEH C18 (50 mm × 2.1 mm, 1.7 μm column and mobile phase of aqueous phosphoric acid and acetonitrile including 0.05% buffer solution under gradient elution. ZGW samples of ZGW I, II, III and IV were obtained and prepared by pre-processing the crude materials of Coptidis rhizoma and Evodiae fructus using four technologies, namely direct water decoction, removal of nonpolar substances in Evodiae fructus by supercritical fluid extraction (SFE, removal of nonpolar substances in ZGW by SFE and removal of nonpolar substances in ZGW by steam distillation. The developed and validated UPLC-PDA method was precise, accurate and sensitive enough based on the facts that the six alkaloids showed good regression (r > 0.9998, the limit of detections and quantifications for six alkaloids were less than 28.8 and 94.5 ng/mL, respectively, and the recovery was in the range of 98.56%–103.24%. The sequence of the total contents of six alkaloids in these samples was ZGW II > ZGW IV > ZGW III > ZGW I. ZGW II, in which nonpolar substances, including essential oils, were firstly removed from Evodiae fructus by SFE, had the highest content of the total alkaloids, indicating that extraction efficiency of the total alkaloids could be remarkably increased after Evodiae fructus being extracted by SFE.

  18. Gastroprotective activity of alkaloid extract and 2-phenylquinoline obtained from the bark of Galipea longiflora Krause (Rutaceae).

    Science.gov (United States)

    Zanatta, Francielle; Gandolfi, Renan Becker; Lemos, Marivane; Ticona, Juan Carlos; Gimenez, Alberto; Clasen, Bruna Kurz; Cechinel Filho, Valdir; de Andrade, Sérgio Faloni

    2009-07-15

    As part of our continuing search for bioactive natural products from plants, the present study was carried out in order to evaluate the gastroprotective properties of alkaloid extract and 2-phenylquinoline obtained from the bark of Galipea longiflora (Rutaceae). Anti-ulcer assays were performed using the following protocols in mice: nonsteroidal anti-inflammatory drug (NSAID)/bethanecol-induced ulcer, ethanol/HCl-induced ulcer, and stress-induced ulcer. The effects of the extract on gastric content volume, pH and total acidity were also evaluated, using the pylorus ligated model. Treatment using doses of 50, 125 and 250 mg/kg of G. longiflora alkaloid extract and positive controls (omeprazol or cimetidine) significantly diminished the lesion index, total lesion area, and percentage of lesion, in comparison with the negative control groups in all the models evaluated. Regarding the model of gastric secretion, a reduction in volume of gastric juice and total acidity was observed, as well as an increase in gastric pH. The main alkaloid of the plant, 2-phenylquinoline, was also evaluated in the ethanol-induced ulcer model. The results showed that at a dose of 50 mg/kg, it significantly inhibited ulcerative lesions. However, this effect was less than that of the alkaloid extract. All these results taken together show that G. longiflora displays gastroprotective activity, as evidenced by its significant inhibition of the formation of ulcers induced by different models. There are indications that mechanisms involved in anti-ulcer activity are related to a decrease in gastric secretion and an increase in gastric mucus content. Also, there is evidence of involvement of NO in the gastroprotector mechanisms. These effects may be attributed, at least in part, to the presence of some alkaloids, particularly 2-phenylquinoline. PMID:19497430

  19. Desenvolvimento e validação de metodologia para quantificação de alcalóides totais como berberina em fitoterápico contendo Berberis vulgaris L. Development and validation of a method for the quantification of total alkaloids as berberine in an herbal medicine containing Berberis vulgaris L.

    Directory of Open Access Journals (Sweden)

    Marcos A.C. Oliveira

    2006-09-01

    Full Text Available A Robusterina® é um produto fitoterápico, com eficácia no tratamento de disfunções do ciclo menstrual. Em sua composição encontram-se Berberis vulgaris L., de ação sedativa e antiespasmódica; Gossypium herbaceum L., enemagoga, hemostática e ocitócica; Viburnum opulus L., antiespasmódico nas cólicas menstruais. De acordo com a Resolução RDC N° 48, de 16 de março de 2004, observa-se que o produto adequa-se na definição de Fitoterápico. A presença de alcalóides em Berberis vulgaris e a ausência de metodologias analíticas de quantificação para o produto, nos incentivaram a propor e validar um método apoiando-nos na Resolução RE N° 899, de 29 de Maio de 2003. Tal metodologia fundamenta-se na determinação espectrofotométrica de alcalóides utilizando-se Dragendorff como reagente precipitante, e o sulfato de berberina MerckÒ, como substância química de referência. A curva de calibração foi determinada com seis concentrações entre 40 e 200 mg/mL. A equação da reta é y = 0,0038x + 0,0092 com R² de 0,9996. Os parâmetros robustez, precisão, especificidade, limite de detecção e quantificação e exatidão foram avaliados estatisticamente com intervalo de confiança de 95% (teste t de Student, ANOVA.Robusterina® is a herbal medicine, with effectiveness in the treatment of menstrual cycle disfunctions. Its composition includes Berberis vulgaris L., with sedative and antispasmodic action; Gossypium herbaceum L., with emmenagogue, hemostatic and ocitocic action; Viburnum opulus L., with antispasmodic action for the treatment of menstrual colics. In accordance with Resolution RDC N° 48, of 16 of March of 2004 (ANVISA, Brazil the product meets the definition of "Fitoterápico" (phytotherapeutic agent. The presence of alkaloids in Berberis vulgaris and the absence of analytical methodologies for quantification of the product, stimulated us to develop and validate a method in accordance with Resolution RE N° 899

  20. Indolopyridoquinazoline alkaloids from Esenbeckia grandiflora mart. (Rutaceae); Alkaloides {beta}-indolopiridoquinazolinicos de Esenbeckia grandiflora mart. (Rutaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Januario, Ana Helena; Vieira, Paulo Cezar; Silva, Maria Fatima das Gracas Fernandes da; Fernandes, Joao Batista [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica], e-mail: anahjanuario@unifran.br; Silva, Jorge Jose de Brito; Conserva, Lucia Maria [Universidade Federal de Alagoas (UFAL), Maceio, AL (Brazil). Inst. de Quimica e Biotecnologia

    2009-07-01

    The chemical composition of two specimens of Esenbeckia grandiflora, collected in the south and northeast regions of Brazil, was investigated. In this study, three b-indolopyridoquinazoline alkaloids from the leaves (rutaecarpine, 1-hydroxyrutaecarpine) and roots (euxylophoricine D) were isolated for the first time in this genus. In addition, the triterpenes {alpha}-amyrin, {beta}-amyrin, {alpha}-amyrenonol, {beta}-amyrenonol, 3{alpha}-hydroxy-ursan-12-one, and 3{alpha}-hydroxy-12,13-epoxy-oleanane, the coumarins auraptene, umbelliferone, pimpinelin, and xanthotoxin, the furoquinoline alkaloids delbine and kokusaginine, and the phytosteroids sitosterol, stigmasterol, campesterol and 3{beta}-O-{beta}-D-glucopyranosylsitosterol were also isolated from the leaves, twigs, roots and stems of this species. Structures of these compounds were established by spectral analysis. (author)

  1. The distribution of inole alkaloids in different organs of Catharanthus roseus G. Don. (Vinca rosea L)

    OpenAIRE

    Hassan Ebrahimzadeh; Azra Ataei -Azimi4 Mohammad-Reza Noori-Dafoi

    1996-01-01

    The study of alkaloid extract of the leaf of Vinca rosea by TLC showed the existence of 13 bands, 7 bands of them were: Serpentine, Vincristine, Vinblastine, Ajmaline, Catharantine, Vindoline and Ajmalicine. The existence of these 7 alkaloids was confirmed in the young leaves, old leaves and the roots of the plant by HPLC. Furthermore, two alkaloids with the short retention times and one alkaloid with the medium retention time in the young leaf, three alkaloids with the short retention time a...

  2. Stereoselective total synthesis of sphingolipids

    Indian Academy of Sciences (India)

    PARAMESH JANGILI; PERLA RAMESH; BISWANATH DAS

    2016-11-01

    A novel sphingosine, 1,2-diacetyl D-erythro-sphinganine having a characteristic almond flavour was isolated from the edible mushroom Grifola gargal. We have synthesized this sphinganine along with the three other sphingolipids, such as 1,2-diacetyl L-threo-sphinganine, D-erythro-sphinganine triacetateand L-threo-sphinganine triacetate using Garner aldehyde as the starting material involving the Grignard reaction and Mitsunobu inversion. The sphingolipids 1,2-diacetyl D-erythro-sphinganine and 1,2-diacetyl L-threo-sphinganine have been synthesized for the first time.

  3. Total synthesis of (-)- and (+)-tedanalactam

    Digital Repository Service at National Institute of Oceanography (India)

    Majik, M.S.; Parameswaran, P.S.; Tilve, S.G.

    are given in Hz. Chiral HPLC analyses was executed using Jasco HPLC model MX-2080-31 instrument. tert-Butyl (3-hydroxypropyl)carbamate (10): The Boc 2 O (5.83 g, 0.026 mol) was added drop wise to a stirred solution of 3-amino-1-propanol 9 (1.744 g, 0... were recorded on a MicroMass ES- QTOF. Chiral HPLC analysis was executed using Jasco HPLC model MX-2080-31 instrument. Melting points were recorded using Thiele apparatus and are uncorrected. S2 2. Copies of 1 H NMR, 13 C NMR and DEPT...

  4. Simple and rapid extraction, separation, and detection of alkaloids in beverages.

    Science.gov (United States)

    Copper, Christine L; Newman, Carl I D; Collins, Greg E

    2008-12-01

    Implementation of an uncomplicated SPE process for the rapid extraction and preconcentration of the alkaloids, colchicine, strychnine, aconitine, and nicotine, from water, apple juice, and nonfat milk samples is presented. When coupled to analysis via micellar EKC (MEKC), the total analysis time per sample was less than 15 min for the water and juice samples and less than 20 min for the milk. The SPE process allowed for anywhere from a three to a fourteen-fold improvement in the LOD for each alkaloid when compared to detecting the alkaloids in a nontreated water sample matrix. Following SPE, the LODs for colchicine, strychnine, and nicotine were sufficient to meet levels from 150 to 5000 times more dilute than the LD(50) for a 50 kg individual drinking 12 oz of a contaminated beverage. Aconitine, on the other hand, was detected at approximately the LD(50) level. The percent recoveries for the SPE ranged from 37% to as high as 99%. Nicotine attained the highest recovery efficiencies, followed by colchicine, and finally, aconitine and strychnine, which were nearly identical. The greatest recovery efficiencies were achieved from apple juice and water, whereas nonfat milk yielded the lowest. PMID:18925621

  5. Ergot Alkaloids in Feed for Pekin Ducks: Toxic Effects, Metabolism and Carry Over into Edible Tissues

    Directory of Open Access Journals (Sweden)

    Sven Dänicke

    2015-06-01

    Full Text Available Hardened sclerotia (ergots of Claviceps purpurea contaminate cereal grains and contain toxic ergot alkaloids (EA. Information on EA toxicity in ducks is scarce. Therefore, the aim of the growth experiment (Day 0–49, n = 54/group was to titrate the lowest observed adverse effect level (LOAEL for total ergot alkaloids (TEA. A control diet was prepared without ergots, and the diets designated Ergot 1 to 4 contained 1, 10, 15 and 20 g ergot per kg diet, respectively, corresponding to TEA contents of 0.0, 0.6, 7.0, 11.4 and 16.4 mg/kg. Sensitivity of ducks to EA was most pronounced at the beginning of the experiment when feed intake decreased significantly by 9%, 28%, 41% and 47% in groups Ergot 1 to 4, respectively, compared to the control group. The experiment was terminated after two weeks for ducks exposed to Ergot 3 and 4 due to significant growth retardation. Ergot alkaloid residues in edible tissues were lower than 5 ng/g. Bile was tested positive for ergonovine (=ergometrine = ergobasine with a mean concentration of 40 ng/g. Overall, the LOAEL amounted to 0.6 mg TA/kg diet suggesting that ducks are not protected by current European Union legislation (1 g ergot/kg unground cereal grains.

  6. Enhancing terpenoid indole alkaloid production by inducible expression of mammalian Bax in Catharanthus roseus cells

    Institute of Scientific and Technical Information of China (English)

    XU MaoJun; DONG JuFang

    2007-01-01

    Bax, a mammalian pro-apoptotic member of the Bcl-2 family, triggers hypersensitive reactions when expressed in plants. To investigate the effects of Bax on the biosynthesis of clinically important natural products in plant cells, we generate transgenic Catharanthus roseus cells overexpressing a mouse Bax protein under the β-estradiol-inducible promoter. The expression of Bax in transgenic Catharanthus roseus cells is highly dependent on β-estradiol concentrations applied. Contents of catharanthine and total terpenoid indole alkaloid of the transgenic cells treated with 30 μmol/L β-estradiol are 5.0- and 5.5-fold of the control cells. Northern and Western blotting results show that expression of mammalian Bax induces transcriptional activation of Tdc and Str, two key genes in terpenoid indole alkaloid biosynthetic pathway of Catharanthus roseus cells, and stimulates the accumulation of defense-related protein PR1 in the cells, showing that the mouse Bax triggers the defense responses of Catharanthus roseus cells and activates the terpenoid indole alkaloid biosynthetic pathway. Thus, our data suggest that the mammalian Bax might be a potential regulatory factor for secondary metabolite biosynthesis in plant cells and imply a new secondary metabolic engineering strategy for enhancing the metabolic flux to natural products by activating the whole biosynthetic pathway rather than by engineering the single structural genes within the pathways.

  7. Enhancing terpenoid indole alkaloid production by inducible expression of mammalian Bax in Catharanthus roseus cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Bax,a mammalian pro-apoptotic member of the Bcl-2 family,triggers hypersensitive reactions when expressed in plants.To investigate the effects of Bax on the biosynthesis of clinically important natural products in plant cells,we generate transgenic Catharanthus roseus cells overexpressing a mouse Bax protein under the β-estradiol-inducible promoter.The expression of Bax in transgenic Catharanthus roseus cells is highly dependent on β-estradiol concentrations applied.Contents of catharanthine and total terpenoid indole alkaloid of the transgenic cells treated with 30 μmol/L β-estradiol are 5.0-and 5.5-fold of the control cells.Northern and Western blotting results show that expression of mammalian Bax induces transcriptional activation of Tdc and Str,two key genes in terpenoid indole alkaloid bio-synthetic pathway of Catharanthus roseus cells,and stimulates the accumulation of defense-related protein PR1 in the cells,showing that the mouse Bax triggers the defense responses of Catharanthus roseus cells and activates the terpenoid indole alkaloid biosynthetic pathway.Thus,our data suggest that the mammalian Bax might be a potential regulatory factor for secondary metabolite biosynthesis in plant cells and imply a new secondary metabolic engineering strategy for enhancing the metabolic flux to natural products by activating the whole biosynthetic pathway rather than by engineering the single structural genes within the pathways.

  8. Identification and simultaneous quantification of five alkaloids in Piper longum L. by HPLC-ESI-MS(n) and UFLC-ESI-MS/MS and their application to Piper nigrum L.

    Science.gov (United States)

    Liu, Hao-Long; Luo, Rong; Chen, Xiao-Qing; Ba, Yin-Ying; Zheng, Li; Guo, Wei-Wei; Wu, Xia

    2015-06-15

    A simple, effective and suitable UFLC-ESI-MS/MS method was firstly developed to simultaneously determine five characteristic constituents (piperine, piperlonguminine, Δα,β-dihydropiperlonguminine, pellitorine and piperanine) of Piper longum L. The total alkaloids of P. longum L. was prepared. The alkaloid contents of Piper nigrum L. and P. longum L. were compared. The analysis was carried out in multiple reaction monitoring scan mode. The method showed a good specificity, linearity (R(2)>0.995), stability (RSDnigrum, P. longum had lower piperine content but was enriched in the other four alkaloids. PMID:25660876

  9. γ-Lactam alkaloids from the flower buds of daylily.

    Science.gov (United States)

    Matsumoto, Takahiro; Nakamura, Seikou; Nakashima, Souichi; Ohta, Tomoe; Yano, Mamiko; Tsujihata, Junichiro; Tsukioka, Junko; Ogawa, Keiko; Fukaya, Masashi; Yoshikawa, Masayuki; Matsuda, Hisashi

    2016-07-01

    Four new alkaloids, hemerocallisamines IV-VII, were isolated from the methanol extract of flower buds of daylily. The chemical structures of the new compounds were elucidated on the basis of chemical and physicochemical evidence. The absolute stereochemistry of the hemerocallisamines IV-VI was elucidated by the application of the modified Mosher's method, HPLC analysis, and optical rotation. In the present study, the isolated alkaloids significantly inhibited the aggregation of Aβ42 in vitro. This is the first report about bioactive alkaloids with a γ-lactam ring from daylily. In addition, isolated nucleosides showed accelerative effects on neurite outgrowth under the non-fasting condition.

  10. Genotoxic and tumorigenic pyrrolizidine alkaloids in Chinese herbal plants

    Institute of Scientific and Technical Information of China (English)

    P.P. Fu; Q. Xia; M.W. Chou; G. Lin

    2005-01-01

    Pyrrolizidine alkaloids are a class of hepatotoxic and tumorigenic compounds detected in Chinese herbal plants,contaminated foods, and dietary supplements. In this review, the sources, toxicity, genotoxicity, tumorigenicity, and the metabolic pathways,particular the activation pathways leading to hepatotoxicity and tumorigenicity, of pyrrolizidine alkaloids are briefly discussed, with a focus on the most recent important findings concerning the genotoxic mechanism by which riddelliine liver tumors. This mechanism involves the formation of 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-derived DNA adducts and may be general to most carcinogenic pyrrolizidine alkaloids.

  11. Prenylindole alkaloids from Raputia praetermissa (Rutaceae) and their chemosystematic significance

    Energy Technology Data Exchange (ETDEWEB)

    Rosas, Lisandra V.; Veiga, Thiago Andre M.; Fernandes, Joao B.; Vieira, Paulo C.; Silva, M. Fatima das G.F. da, E-mail: dmfs@power.ufscar.b [Universidade Federal de Sao Carlos (DQ/UFSCar), SP (Brazil). Dept. de Quimica

    2011-07-01

    The dichloromethane extract from the stems of Raputia praetermissa afforded four new compounds, 4-deoxyraputindole C (1), raputimonoindole A-B (2, 3), and hexadecanyl 2-hydroxy- 4-methoxy-cinnamate (5), besides the alkaloids 5-(4-methoxymethylfuran-2-yl)-1H-indole (raputimonoindole C), furoquinolines maculosidine, robustine, evolitrine and dictamnine. The hexane extract yielded N-methyl-4-methoxyquinoline-2(1H)-one, skimmianine, cycloartenone, sitosterol, stigmasterol and sitostenone. The anthranilate alkaloid content indicates that the genus is strongly related to those included in Cusparieae tribe, but differs from Neoraputia by the absence of prenylindole alkaloids in the late, whose species have previously been placed in Raputia. (author)

  12. Total synthesis and evaluation of vinblastine analogues containing systematic deep-seated modifications in the vindoline subunit ring system: core redesign.

    Science.gov (United States)

    Schleicher, Kristin D; Sasaki, Yoshikazu; Tam, Annie; Kato, Daisuke; Duncan, Katharine K; Boger, Dale L

    2013-01-24

    The total synthesis of a systematic series of vinblastine analogues that contain deep-seated structural modifications to the core ring system of the lower vindoline subunit is described. Complementary to the vindoline 6,5 DE ring system, compounds with 5,5, 6,6, and the reversed 5,6 membered DE ring systems were prepared. Both the natural cis and unnatural trans 6,6-membered ring systems proved accessible, with the latter representing a surprisingly effective class for analogue design. Following Fe(III)-promoted coupling with catharanthine and in situ oxidation to provide the corresponding vinblastine analogues, their evaluation provided unanticipated insights into how the structure of the vindoline subunit contributes to activity. Two potent analogues (81 and 44) possessing two different unprecedented modifications to the vindoline subunit core architecture were discovered that matched the potency of the comparison natural products and both lack the 6,7-double bond whose removal in vinblastine leads to a 100-fold drop in activity.

  13. Total synthesis and in vitro bioevaluation of clavaminols A, C, H & deacetyl clavaminol H as potential chemotherapeutic and antibiofilm agents.

    Science.gov (United States)

    Vijai Kumar Reddy, T; Jyotsna, A; Prabhavathi Devi, B L A; Prasad, R B N; Poornachandra, Y; Ganesh Kumar, C

    2016-09-14

    A highly concise and expedient total synthesis of bioactive clavaminols (1-4) has been executed using commercially available achiral compound decanol. The synthetic strategy relied on trans-Wittig olefination, Sharpless asymmetric epoxidation, regioselective azidolysis and in situ detosylation followed by reduction as key reactions with good overall yield. Based on biological evaluation studies of all the synthesized compounds, it was observed that the clavaminol A (1) exhibited good cytotoxicity against DU145 and SKOV3 cell lines with IC50 value of 10.8 and 12.5 μM, respectively. Clavaminol A (1) and deacetyl clavaminol H (3) displayed selective promising inhibition towards Gram-positive pathogenic bacterial strains and showed good antifungal activity against the tested Candida strains. In addition, compounds 1 and 3 have demonstrated significant bactericidal activity. Compound 3 was found to be equipotent to the standard drug Miconazole displaying MFC value of 15.6 μg/mL against Candida albicans MTCC 854, C. albicans MTCC 1637, C. albicans MTCC 3958 and Candida glabrata MTCC 3019. Compounds 1 and 3 were also able to inhibit the biofilm formation of Micrococcus luteus MTCC 2470 and Staphylococcus aureus MLS16 MTCC 2940. Clavaminol A (1) increased the levels of reactive oxygen species (ROS) accumulation in M. luteus MTCC 2470. PMID:27187861

  14. Part 1. Approaches to the total synthesis of the diterpene marrubin. Part II. Ligand assisted nucleophilic additions. Part III. Coal processing in a non-dissolving medium

    Energy Technology Data Exchange (ETDEWEB)

    Lipscombe, J.; Charles, W. II

    1987-01-01

    The total synthesis of the diterpene marrubiin was attempted using methodology previously developed in the Liotta laboratories. Ligand Assisted Nucleophilic Additions (LANA) comprise a new class of synthetic reactions involving the stereoselective addition of some group, usually in an intramolecular conjugate fashion. This group is itself derived from an earlier nucleophilic addition to a carbonyl moiety. Exchange of the original metal of the alkoxide with a second metal (which must be at least divalent) having a transferrable group demands that the stereochemistry of the first addition control the second. The general features of these types of processes are discussed. Initial work with substituted quinones is presented, and some mechanistic rationales are given. A novel method of coal processing at modest temperatures and hydrogen pressures (250-300/sup 0/C, 8.0 MPa) is discussed. Coals reacted with small amounts of tetrahydroquinoline in the presence of fluorocarbons or other non-dissolving media underwent astounding increases in pyridine solubility, a common standard in coal liquefaction studies. Several additives were employed, although only tetrahydroquinoline was found to effectively increase coal solubility. Coals having vastly different individual properties behaved similarly under these conditions. Kinetic and model studies were used in an attempt to clarify the reactions occurring under these novel conditions.

  15. Antifouling Alkaloids from Crinum augustum (Amaryllidaceae

    Directory of Open Access Journals (Sweden)

    John Refaat

    2009-01-01

    Full Text Available Fractionation and purification of the ethanolic extract of the bulbs of Crinum augustum Rox. (Amaryllidaceae cultivated in Egypt yielded five alkaloids 6-methoxy-crinamine (1 , crinamine (2 , buphanisine (3 , ungeremine (4 , and hippadine (5 ; two fatty acid derivatives: myristic acid ethyl ester (6 and palmitic acid ethyl ester (7 ; four terpenoidal and steroidal compounds: ursolic acid (8 , β-sitosterol-O- β glucopyranoside (9 and mixture of β--sitosterol (10 and stigmasterol (11 . The structures of all compounds were determined by interpretation of their spectroscopic data; 1D ( 1 H and 13 C, 2D (HSQC, COSY, DQF, NOE and HMBC NMR; MS and UV analyses. The compounds (1 -4 and (6-8 were tested towards biofouling activity using larvae of barnacle Balance amphitrie. Significant activities of 1, 2 and 3 with EC 50 1.8, 1.2 and 0.75 μg/mL respectively, were observed.

  16. Pyrrolidonyl and pyridyl alkaloids in Lymantria dispar.

    Science.gov (United States)

    Deml, Reinhold

    2003-01-01

    The occurrence and metabolism of nicotine and related N-containing compounds in body fluids of the gipsy moth were addressed. Thin layer chromatographic studies clearly showed the simultaneous presence of GABA and 2-pyrrolidone but not of GABamide in the larval haemolymph and osmeterial secretion of Lymantria dispar as well as in the corresponding body fluids of the saturniids, Saturnia pavonia and Attacus atlas. Furthermore, feeding and injection experiments using alkylated precursors and combined gas chromatography/mass spectrometry gave evidence of the transformation of 2-pyrrolidone to nicotine and of nicotinic acid to nicotinamide in caterpillars of L. dispar. Based on these results, on the earlier described variation of the secondary-compound patterns of L. dispar during its development, and on literature data, metabolic pathways for the hitherto detected pyridyl and pyrrolidonyl alkaloids in Lymantriidae (and possibly Saturniidae) are proposed.

  17. Investigation of Aconitine-type Alkaloids from Processed Tuber of Aconitum carmiechaeli by HPLC-ESI-MS/MSn

    Institute of Scientific and Technical Information of China (English)

    YUE Hao; PI Zi-feng; ZHAO Yu-feng; SONG Feng-rui; LIU Zhi-qiang; LIU Shu-ying

    2007-01-01

    @@ Introduction Aconitine-type alkaloids isolated from the roots of Aconitum carmiechaeli show a potential toxicity and a broad spectrum of bioactivity[1-4]. On the basis of the C8-substituent of C19-diterpenoid skeleton, aconitinetype alkaloids can be divided into diester-diterpenoid alkaloids( DDAs), monoester-diterpenoid alkaloids(MDAs), and lipo-alkaloids( Fig. 1 ).

  18. A New Binary Carbazole Alkaloid from Murraya koenigii

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new binary carbazole alkaloid, 8, 8"-biskoenigine (1), along with its monomer,kocnigine, was isolated from the dried leaves of Murraya koenigii collected in Xishuangbanna,Yunnan province. The structure of 1 was established by spectroscopic methods.

  19. Activity of pyrrolizidine alkaloids against biofilm formation and Trichomonas vaginalis

    Science.gov (United States)

    Crotalaria genus belongs to the subfamily Papilionoideae comprising about 600 species spread throughout tropical, neotropical and subtropical regions. In this study, seeds of Crolatalaria pallida were used to the isolation of usaramine, a pyrrolizidine alkaloid. Thus, Pseudomonas aeruginosa and Stap...

  20. New bisbenzylisoquinoline alkaloid from Laureliopsis philippiana

    DEFF Research Database (Denmark)

    Stærk, Dan; Thi, Loi Pham; Rasmussen, Hasse Bonde;

    2009-01-01

    Phytochemical investigation of Laureliopsis philippiana resulted in isolation of a new bisbenzylisoquinoline alkaloid (1) named laureliopsine A. The structure was established by spectroscopic methods, including 2D homo- and heteronuclear NMR experiments. This finding of a bisbenzylisoquinoline al...