WorldWideScience

Sample records for cinchona

  1. Composition of the endophytic filamentous fungi associated with Cinchona ledgeriana seeds and production of Cinchona alkaloids.

    Science.gov (United States)

    Maehara, Shoji; Agusta, Andria; Kitamura, Chinami; Ohashi, Kazuyoshi; Shibuya, Hirotaka

    2016-04-01

    Four kinds of endophytic filamentous fungi (code names: CLS-1, CLS-2, CLS-3, and CLS-4) associated with the seeds of Cinchona ledgeriana (Rubiaceae) from West Java, Indonesia, were isolated. All of the isolates were classified into Diaporthe spp. based on phylogenetic analysis of the nucleotide sequences of the internal transcribed spacers (ITS1 and ITS2) including the 5.8S ribosomal DNA region. All four of these endophytic fungi produce Cinchona alkaloids, mainly quinine and quinidine, in synthetic liquid medium. PMID:26645397

  2. Fused triazoles via tandem reactions of activated Cinchona alkaloids with azide ion. Second Cinchona rearrangement exemplified.

    Science.gov (United States)

    Röper, S; Franz, M H; Wartchow, R; Hoffmann, H M R

    2003-08-01

    [reaction: see text] Intramolecular 1,3-dipolar cycloadditions of cinchona azides to the C10-C11 alkyne and C10-C11 olefin unit of the alkaloid have been designed via tandem strategy. A variety of fused triazoles and triazolines with a bis-azahomotwistane skeleton have been prepared. In trifluoroethanol, O-mesylcinchonidine 7-OMs and NaN(3) furnish triazole 8 as well as cage-expanded 1,5-diazatricyclo[4.4.1.0(3,8)]undecane derivative 10. Both fused triazoles 8 and 10 are formed with retention of configuration at C9 and C3, respectively. 1-Azabicyclo[3.2.2]cage expansion is shown to be reversible. PMID:12889871

  3. Quinine, Malaria, and the Cinchona Bureau: Marketing Practices and Knowledge Circulation in a Dutch Transoceanic Cinchona-Quinine Enterprise (1920s-30s).

    Science.gov (United States)

    Van Der Hoogte, Arjo Roersch; Pieters, Toine

    2016-04-01

    In this study, we will show how a Dutch pharmaceutical consortium of cinchona producers and quinine manufacturers was able to capitalize on one of the first international public health campaigns to fight malaria, thereby promoting the sale of quinine, an antimalarial medicine. During the 1920s and 1930s, the international markets for quinine were controlled by this Dutch consortium, which was a transoceanic cinchona-quinine enterprise centered in the Cinchona Bureau in the Netherlands. We will argue that during the interwar period, the Cinchona Bureau became the decision-making center of this Dutch cinchona-quinine pharmaceutical enterprise and monopolized the production and trade of an essential medicine. In addition, we will argue that capitalizing on the international public health campaign in the fight against malaria by the Dutch cinchona-quinine enterprise via the Cinchona Bureau can be regarded as an early example of corporate colonization of public health by a private pharmaceutical consortium. Furthermore, we will show how commercial interests prevailed over scientific interests within the Dutch cinchona-quinine consortium, thus interfering with and ultimately curtailing the transoceanic circulation of knowledge in the Dutch empire. PMID:26054829

  4. Enantioselective Nazarov Cyclization Catalyzed by a Cinchona Alkaloid Derivative

    Science.gov (United States)

    Huang, Yu-Wen; Frontier, Alison J.

    2015-01-01

    Nucleophilic catalysts for a 1,6 addition/Nazarov cyclization/elimination sequence were evaluated for their ability to induce enantioselectivity in the electrocyclization step. Of the tertiary amines examined, it was found that a cinchona alkaloid derivative was able to generate substituted 5-hydroxy γ-methylene cyclopentenones with excellent enantioselectivity. The study results suggest that successful cyclization depends upon the ability of the dienyl diketone substrate to readily adopt an s-cis conformation. PMID:26085696

  5. Recyclable fluorous cinchona alkaloid ester as a chiral promoter for asymmetric fluorination of β-ketoesters

    Directory of Open Access Journals (Sweden)

    Wen-Bin Yi

    2012-08-01

    Full Text Available A fluorous cinchona alkaloid ester has been developed as a chiral promoter for the asymmetric fluorination of β-ketoesters. It has comparable reactivity and selectivity to the nonfluorous versions of cinchona alkaloids and can be easily recovered from the reaction mixture by simple fluorous solid-phase extraction (F-SPE and used for the next round of reaction without further purification.

  6. Origins of stereoselectivity in intramolecular aldol reactions catalyzed by cinchona amines.

    Science.gov (United States)

    Lam, Yu-Hong; Houk, K N

    2015-02-11

    The intramolecular aldol condensation of 4-substituted heptane-2,6-diones leads to chiral cyclohexenones. The origins of the enantioselectivities of this reaction, disclosed by List et al. using a cinchona alkaloid-derived primary amine (cinchona amine) organocatalyst, have been determined with dispersion-corrected density functional theory (DFT). The stereocontrol hinges on the chair preference of the substrate-enamine intermediate and the conformational preferences of a hydrogen-bonded nine-membered aldol transition state containing eight heavy atoms. The conformations of the hydrogen-bonded ring in the various stereoisomeric transition structures have been analyzed in detail and shown to closely resemble the conformers of cyclooctane. A model of stereoselectivity is proposed for the cinchona amine catalysis of this reaction. The inclusion of Grimme's dispersion corrections in the DFT calculations (B3LYP-D3(BJ)) substantially improves the agreement of the computed energetics and experiment, attesting to the importance of dispersion effects in stereoselectivity. PMID:25629689

  7. Synthesis, structure and in vitro cytostatic activity of ferrocene-Cinchona hybrids.

    Science.gov (United States)

    Kocsis, László; Szabó, Ildikó; Bősze, Szilvia; Jernei, Tamás; Hudecz, Ferenc; Csámpai, Antal

    2016-02-01

    Exploring copper(I)- and ruthenium(II)-catalyzed azide-alkyne cycloadditions and a Sonogashira protocol, novel cytostatic ferrocene-cinchona hybrids were synthetized displaying significant in vitro activity on HepG-2 and HT-29 cells. Preliminary SAR studies disclosed that compounds incorporating linkers with 1,2,3-triazole and chalchone residues can be considered as promising lead structures. According to the best of our knowledge this is the first letter on the incorporation of ferrocene nucleus in the reputed cinchona family via triazole and chalcone linkers with established pharmaceutical profile. PMID:26739780

  8. HPTLC method for the estimation of alkaloids of Cinchona officinalis stem bark and its marketed formulations.

    Science.gov (United States)

    Ravishankara, M N; Shrivastava, N; Padh, H; Rajani, M

    2001-04-01

    We report a sensitive method for the estimation of quinine (Qn), cinchonine (Cn), and cinchonidine (Cnd) and a new method based on fluorescence enhancement and detection and quantification of quinidine (Qnd) from Cinchona stem bark and its formulations, using HPTLC. Standard solutions of Qn, Qnd, Cn, and Cnd were applied on precoated HPTLC plates and developed with chloroform/diethylamine (9.6:1.4 v/v). The plates were scanned and quantified at 226 nm for Qn, Cn, Cnd and for Qnd at 366 nm in fluorescence and reflectance mode ([symbol: see text] K400 filter). The method was validated for precision, accuracy and repeatability. Further, the stem bark of Cinchona officinalis and some herbal and homeopathic formulations were evaluated for their individual alkaloid content applying the developed method. PMID:11345710

  9. Highly enantioselective phenylacetylene addition to aromatic ketones catalyzed by cinchona alkaloid-aluminum complexes.

    Science.gov (United States)

    Liu, Lei; Wang, Rui; Kang, Yong-Feng; Chen, Chao; Xu, Zhao-Qing; Zhou, Yi-Feng; Ni, Ming; Cai, Hua-Qing; Gong, Mao-Zhen

    2005-02-01

    The catalytic asymmetric addition of phenylacetylene to aromatic ketones is reported. The catalyst, generated from commercially available Cinchona alkaloids and industrially available triethylaluminum, gives the expected tertiary alcohols with good enantiomeric excess (70-89%) and yields (60-83%). No previous case has been reported successfully using triethylaluminum as a Lewis acid in the asymmetric alkynylation of carbonylic derivatives, and thus we provide a new method to obtain optically active tertiary propargyl alcohols. PMID:15675878

  10. Salts of phenylacetic acid and 4-hydroxyphenylacetic acid with Cinchona alkaloids: Crystal structures, thermal analysis and FTIR spectroscopy

    Science.gov (United States)

    Amombo Noa, Francoise M.; Jacobs, Ayesha

    2016-06-01

    Seven salts were formed with phenylacetic acid (PAA), 4-hydroxyphenylacetic acid (HPAA) and the Cinchona alkaloids; cinchonidine (CIND), quinidine (QUID) and quinine (QUIN). For all the structures the proton was transferred from the carboxylic acid of the PAA/HPAA to the quinuclidine nitrogen of the respective Cinchona alkaloid. For six of the salts, water was included in the crystal structures with one of these also incorporating an isopropanol solvent molecule. However HPAA co-crystallised with quinine to form an anhydrous salt, (HPAA-)(QUIN+). The thermal stability of the salts were determined and differential scanning calorimetry revealed that the (HPAA-)(QUIN+) salt had the highest thermal stability compared to the other salt hydrates. The salts were also characterized using Fourier transform infrared spectroscopy. (PAA-)(QUID+)·H2O and (PAA-)(QUIN+)·H2O are isostructural and Hirshfeld surface analysis was completed to compare the intermolecular interactions in these two structures.

  11. Science in the service of colonial agro-industrialism : the case of cinchona cultivation in the Dutch and British East Indies, 1852-1900

    NARCIS (Netherlands)

    Roersch van der Hoogte, Arjo; Pieters, Toine

    2014-01-01

    The isolation of quinine from cinchona bark in 1820 opened new possibilities for the mass-production and consumption of a popular medicine that was suitable for the treatment of intermittent (malarial) fevers and other diseases. As the 19th century European empires expanded in Africa and Asia, contr

  12. Science in the service of colonial agro-industrialism: the case of cinchona cultivation in the Dutch and British East Indies, 1852-1900.

    Science.gov (United States)

    Roersch van der Hoogte, Arjo; Pieters, Toine

    2014-09-01

    The isolation of quinine from cinchona bark in 1820 opened new possibilities for the mass-production and consumption of a popular medicine that was suitable for the treatment of intermittent (malarial) fevers and other diseases. As the 19th century European empires expanded in Africa and Asia, control of tropical diseases such as malaria was seen as crucial. Consequently, quinine and cinchona became a pivotal tool of British, French, German and Dutch empire-builders. This comparative study shows how the interplay between science, industry and government resulted in different historical trajectories for cinchona and quinine in the Dutch and British Empires during the second half of the 19th century. We argue that in the Dutch case the vectors of assemblage that provided the institutional and physical framework for communication, exchange and control represent an early example of commodification of colonial science. Furthermore, both historical trajectories show how the employment of the laboratory as a new device materialised within the colonial context of agricultural and industrial production of raw materials (cinchona bark), semi-finished product (quinine sulphate) and plant-based medicines like quinine. Hence, illustrating the 19th century transition from 'colonial botany' and 'green imperialism' to what we conceptualise as 'colonial agro-industrialism'. PMID:24981994

  13. 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

  14. Regulación en el uso de la tierra con fines preventivos en los alrededores del cuadrante de la antigua comunidad de Cinchona, Alajuela, Costa Rica

    Directory of Open Access Journals (Sweden)

    Esquivel Valverde, Lidier

    2011-07-01

    Full Text Available La regulación del uso de la tierra permite establecer cuales lugares son aptas para el establecimiento de zonas habitacionales, comercios, industria, actividades agrícolas, actividades turísticas, entre otras, evitando incrementar la vulnerabilidad física o ambiental. El presente artículo se basa en un estudio realizado a la comunidad de Cinchona a raíz del sismo del año 2009, el cual, por las características topográficas y geológicas de la región, generó una cantidad alta de daños a la infraestructura y pérdida de vidas humanas, lo que propició la elaboración de una herramienta técnica normativa que regulara el uso de la tierra en esa zona. La investigación consideró aspectos como el uso de la tierra antes del sismo, tenencia de la tierra, producción agropecuaria, valor de la tierra, pendientes de terreno, geomorfología, capacidad de uso de la tierra, aguas subterráneas, zonas de vida y áreas silvestres y por último las amenazas más relevantes. Como resultado del estudio se presenta en el artículo un resumen de la regulación de tierra propuesta, la cual comprende el sector de Vieja Cinchona (zona devastada por el sismo y las microcuencas cercanas Land use regulations allow to identify suitable places to establish housing, commerce, industry, agricultural activities, and tourism, among others, avoiding to increase physical or environmental vulnerability. This article is based on a study developed at the Cinchona community after the 2009 earthquake, which due to the topographic and geological characteristics generated a lot of damages to infrastructures and losses of human lives. In this context, a normative technical tool was developed to regulate the land use in the zone. The investigation considered aspects such as land use before the earthquake, land possession, farming production, land value, land slopes, geomorphology, land use capacity, underground water, wild life areas and most relevant threats. As a result of

  15. Conservación de plantas regeneradas in vitro y análisis de la variación somaclonal de Cinchona officinalis, Linneo

    OpenAIRE

    Armijos González, Rosa

    2016-01-01

    Cinchona officinalis (Rubiaceae), especie endémica del Valle de Loja, ubicado en la región sur del Ecuador, es un recurso forestal de importancia medicinal y ecológica, además la especie ha sido catalogada como planta nacional y es un ícono de la región sur por su aporte a la farmacopea mundial. Esta especie, entre los siglos XVII-XIX sufrió una gran presión en sus poblaciones debido a la extracción masiva de la corteza para la cura del paludismo. Aunque la actividad extractiva generó grandes...

  16. [The complex travel of cinchona barks between Peru and Québec Hôtel-Dieu, in the middle of the eighteenth century].

    Science.gov (United States)

    Simon, Lorène; Lafont, Olivier

    2016-03-01

    Duplessis sisters, who were religious nuns in Hôtel-Dieu (Quebec hospital), were exchanging letters with a French apothecary from Dieppe in Normandy, named Jacques-Tranquilain Féret. They asked him to send them in Quebec the drugs and medicines their apothecary needed. Amongst these drugs were cinchona barks that came from Callao in Peru by boat, passed Cape Horn and then sailed to Cadiz, the great Spanish port. Then they embarked to Rouen, which was the French port for goods coming from overseas. The goods from Peru had then to be transported on little fishing boats to Dieppe, where Féret received the barks. The apothecary sent these drugs to Quebec by boats sailing either from Rouen or from La Rochelle. So these Peruvian drugs had to cross two times the Ocean before accessing to North America. PMID:27281933

  17. Procesos de ladera cosísmicos del terremoto de Cinchona (Costa Rica del 8 de enero de 2009 (Ms= 6,2

    Directory of Open Access Journals (Sweden)

    Adolfo Quesada Román

    2016-02-01

    Full Text Available The Cinchona earthquake of January 8, 2009, caused great physical impacts such as the destruction of the public and private infrastructure, including social, and left a total of 2,326 persons displaced, 91 injured, 7 missing, and 25 dead. Based on aerial photographs and the implementation of high resolution LiDAR, after the earthquake, 1,900 hillside processes were classified based on the Works of Alcántara- Ayala (2000, Cruden and Varnes (1996 and Highland y Bobrowsky (2008. The importance of this work for Costa Rica lies in the fact that it is the first time the international classification of hillside processes of the WP/WLI established in 1990 was used.

  18. Avaliação de parâmetros de extração da Cinchona Vahl por métodos farmacopéicos e não farmacopéicos Extraction parameters from Cinchona pubescens Vahl using pharmacopeia and no pharmacopeia methods

    Directory of Open Access Journals (Sweden)

    Iarah Daniela Dantas Silva

    2009-09-01

    Full Text Available O presente estudo teve como objetivo a otimização de parâmetros cinéticos de extração da Cinchona pubescens Vahl por ultra-som, usando métodos farmacopéicos e não farmacopéicos. Na extração por ultrasom variaram-se o tempo, a massa, a faixa granulométrica, o volume de solvente e o tipo de solvente. Na decocção, as extrações foram feitas no tempo e temperatura descrita na Farmacopéia Brasileira IV, variando-se o sistema solvente. Na extração por maceração variaram-se o tempo e o sistema solvente. O teor de alcalóides quinolínicos foi monitorado por espectrofotometria no UV a 325 nm. O método decocção foi o que apresentou o maior rendimento na extração dos alcalóides, dados equivalentes foram conseguidos com o método ultra-som, no tempo de 5 min e solvente acidificado pH 4, com um rendimento maior ao da maceração. Pela aplicação do planejamento fatorial para o método do ultra-som foi visto que há uma interação entre as variáveis, necessitando de um melhor ajuste entre elas a fim de melhorar a eficiência extrativa do método do ultra-som.The present study for ultrasound had as objective the optimization of kinetic parameters of extraction of the Cinchona pubescens Vahl, using pharmacopeia and no pharmacopeia methods. In the extraction for ultrasound they had varied the time, the solvent type, the mass, the volume of solvent and grain size of the sample. In the decoction, the extractions had been made according to the time and temperature described in Brazilian Pharmacopeia IV, varying the solvent system. In the extraction for maceration the time and the solvent system had varied. The alkali of the Cinchona pubescens Vahl, was monitored by spectrophotometry in UV 325 nm. The method decoction was the one that presented the biggest income in the alkaloids extraction, given equivalent data had been obtained with the method ultrasound, in the solvent acidified pH 4 and time of 5 min, with a bigger income than the

  19. Avaliação de parâmetros de extração da Cinchona Vahl por métodos farmacopéicos e não farmacopéicos Extraction parameters from Cinchona pubescens Vahl using pharmacopeia and no pharmacopeia methods

    OpenAIRE

    Iarah Daniela Dantas Silva; Cícero Flávio Soares Aragão

    2009-01-01

    O presente estudo teve como objetivo a otimização de parâmetros cinéticos de extração da Cinchona pubescens Vahl por ultra-som, usando métodos farmacopéicos e não farmacopéicos. Na extração por ultrasom variaram-se o tempo, a massa, a faixa granulométrica, o volume de solvente e o tipo de solvente. Na decocção, as extrações foram feitas no tempo e temperatura descrita na Farmacopéia Brasileira IV, variando-se o sistema solvente. Na extração por maceração variaram-se o tempo e o sistema solven...

  20. Mechanistic considerations of enantiorecognition on novel Cinchona alkaloid-based zwitterionic chiral stationary phases from the aspect of the separation of trans-paroxetine enantiomers as model compounds.

    Science.gov (United States)

    Grecsó, Nóra; Kohout, Michal; Carotti, Andrea; Sardella, Roccaldo; Natalini, Benedetto; Fülöp, Ferenc; Lindner, Wolfgang; Péter, Antal; Ilisz, István

    2016-05-30

    The enantiomers of trans-paroxetine were separated on four chiral stationary phases (CSPs) based on chiral zwitterionic Cinchona alkaloids fused with (R,R)- or (S,S)-trans-2-aminocyclohexanesulfonic acid. The enantioseparations were carried out in polar-ionic or in hydro-organic mobile phases with MeOH/THF, MeCN/THF, MeCN/THF/H2O and MeOH/MeCN/THF containing organic acid and base additives, in the temperature range 0-50°C. The effects of the mobile phase composition, the natures and concentrations of the additives and temperature on the separations were investigated. Thermodynamic parameters were calculated from plots of ln α vs 1/T. Δ(ΔH°) ranged between -3.0 and +1.5 kJ mol(-1), and Δ(ΔS°) between -8.8 and +5.9 J mol(-1)K(-1). The enantioseparation was generally enthalpically controlled, the retention factor and separation factor decreasing with increasing temperature, but entropically controlled separation was also observed. The elution sequences of the paroxetine enantiomers on the two pairs of pseudo-enantiomeric CSPs were investigated, and an attempt was made to explain the observed anomalies in silico in order to gain an insight into the underlying molecular recognition events between the four chiral selectors and the analyte enantiomers. PMID:26955754

  1. 金鸡纳生物碱-9-O-三甲基硅衍生物催化的不对称“中断”Feist-Bénary反应%Cinchona Alkaloid-9-O-trimethylsilyl Derivatives as Organocatalysts for the Asymmetric Interrupted” Feist-Bénary Reaction

    Institute of Scientific and Technical Information of China (English)

    金瑛; 张天一; 昌盛

    2012-01-01

    Cinchona alkaloid-9-0-trimethylsilyl(TMS) derivatives have been used to catalyze the asymmetric interrupted " Feist-B6nary reaction of ethyl bromopyruvate/substituted bromo-ketoesters with 1,3-cyclohexadione. The corresponding hydroxydihydrofurans have been obtained in excellent yields (85% ~ 97% ) and with up to 90% ee value.%将6种金鸡纳生物碱-9-O-三甲基硅(TMS)衍生物用于催化环己二酮与溴乙酰甲酸乙酯/β取代的溴乙酰甲酸乙酯的不对称“中断的”Feist-Bénary反应,得到了高的化学产率(85%~97%)和最高达90%ee的立体选择性.

  2. 金鸡纳生物碱-9-O-脯氨酸酯衍生物催化的不对称“中断的”Feist-Bénary反应%Cinchona alkaloid-9-O-proline ester derivatives as organocatalysts for asymmetric “ interrupted” Feist-Bénary reaction

    Institute of Scientific and Technical Information of China (English)

    张天一; 张巍; 李妍; 金瑛

    2012-01-01

    4种金鸡纳生物碱-9-O-脯氨酸酯衍生物用于催化环己二酮与溴乙酰甲酸乙酯的不对称“中断的”Feist-Bénary反应,得到了高的化学产率(>92%)和最高为72% e.e.的立体选择性.%Four cinchona alkaloid-9-O-proline ester derivatives were used to catalyze the asymmetric " interrupted " Feist-B6nary reaction of ethyl bromopyruvate bromo-ketoesters and 1,3-cyclohexadione. The corresponding hydroxydihydro-furans were obtained in excellent yields ( > 92% ) and with up to 72% e. e. .

  3. Fluorescence studies of some protonated cinchona alkaloids in polymers

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Joshi, Neeraj; Rautela, Ranjana [Photophysics Laboratory, Department of Physics, D.S.B. Campus, Kumaun University, Nainital 263002 (India); Joshi, Hem Chandra, E-mail: hem_sup@yahoo.co.u [Institute for Plasma Research, Laser Diagnostics Division, Bhat, Near Indira Bridge, Gandhinagar, Gujarat 382428 (India); Pant, Sanjay, E-mail: sanjaypent@yahoo.co [Photophysics Laboratory, Department of Physics, D.S.B. Campus, Kumaun University, Nainital 263002 (India)

    2011-07-15

    In the present paper we report spectral and photophysical properties of two probes viz. cinchonidine and quinidine in two different polymers viz. polyvinyl alcohol (PVA) and polymethylmethacrylate (PMMA). The emission spectra exhibit edge excitation red shift (EERS) for both the probes and multiexponential decays are observed. Presence of various conformers and geometries is suggested to explain the observed results. The photophysical properties and excited state behavior of Cd++ are more sensitive towards the microenvironment of the polymer. - Research highlights: {yields} We report photophysical properties of cinchonidine and quinidine in PMMA and PVA. {yields} The emission spectra exhibit edge excitation red shift and multiexponential decays. {yields} Presence of conformers and geometries is suggested to explain the observed results.

  4. Drug: D08460 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available gif Cinchona [TAX:43462], Cinchona calisaya [TAX:153742], Cinchona succirubra, Cinchona calisaya Antiprotozoa...[BR:br08302] Antiparasitics Antiprotozoals Quinine D08460 Quinine (BAN) Antiinfectives [BR:br08307] Antipara

  5. Synthesis of Chiral Chalcone Derivatives Catalyzed by the Chiral Cinchona Alkaloid Squaramide

    Directory of Open Access Journals (Sweden)

    Dandan Xie

    2014-11-01

    Full Text Available An effective method has been developed for the preparation of novel chiral chalcone derivatives under mild conditions from the easily accessible starting materials nitromethane and chalcone derivatives 2. The corresponding products were obtained in moderate yields with excellent enantioselectivities (up to 99%.

  6. Synthesis of Chiral Chalcone Derivatives Catalyzed by the Chiral Cinchona Alkaloid Squaramide

    OpenAIRE

    Dandan Xie; Ying Xie; Yan Ding; Jian Wu; Deyu Hu

    2014-01-01

    An effective method has been developed for the preparation of novel chiral chalcone derivatives under mild conditions from the easily accessible starting materials nitromethane and chalcone derivatives 2. The corresponding products were obtained in moderate yields with excellent enantioselectivities (up to 99%).

  7. 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

  8. Optimization of Extraction Conditions and HPTLC - UV Method for Determination of Quinine in Different Extracts of Cinchona species Bark

    Directory of Open Access Journals (Sweden)

    Dharam C. Jain

    2008-10-01

    Full Text Available A simple, precise and accurate high-performance thin-layer chromatographic method has been established for quantitative determination of quinine. Conditions were also optimized for best possible extraction of quinine via varying concentrations of diethyl amine in different solvents (n-hexane, chloroform, ethyl acetate and methanol for maximum recovery of quinine. Methanol modified with 20 % DEA found to be best for highest possible recovery of target analyte quinine. Chromatographic separation of quinine was performed on silica gel 60 F 254 HPTLC plates with ethyl acetate : diethyl amine in the proportion 88 : 12 (v/v, as mobile phase. The determination was carried out using the densitometric absorbance mode at 236 nm. Quinine response was found to be linear over the range 4–24 μg spot −1. The HPTLC method was evaluated in terms of specificity, precision, reproducibility, LOD – LOQ and robustness. Beside these parameters, number of theoretical plates and flow constant were also included as a part of validation

  9. 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.

  10. Non-aqueous capillary electrophoretic enantioseparation of N-derivatized amino acids using cinchona alkaloids and derivatives as chiral counter-ions.

    OpenAIRE

    Piette, Véronique; Fillet, Marianne; Lindner, W.; Crommen, Jacques

    2000-01-01

    A non-aqueous capillary electrophoretic method developed with quinine and tert.-butyl carbamoylated quinine as chiral selectors for the enantioseparation of N-protected amino acids was applied to the investigation of other quinine derivatives as chiral additives. The optimum composition of the background electrolyte was found to be 12.5 mM ammonia, 100 mM octanoic acid and 10 mM chiral selector in an ethanol-methanol (60:40, v/v) mixture. Under these conditions, a series of chiral acids, as v...

  11. Comparison of the Separation Performances of Cinchona Alkaloid-Based Zwitterionic Stationary Phases in the Enantioseparation of β2- and β3-Amino Acids

    Directory of Open Access Journals (Sweden)

    István Ilisz

    2014-12-01

    Full Text Available The enantiomers of twelve unusual β2- and β3-homoamino acids containing the same side-chains were separated on chiral stationary phases containing a quinine- or quinidine-based zwitterionic ion-exchanger as chiral selector. The effects of the mobile phase composition, the nature and concentration of the acid and base additives and temperature on the separations were investigated. The changes in standard enthalpy, ∆(∆H°, entropy, ∆(∆S°, and free energy, ∆(∆G°, were calculated from the linear van’t Hoff plots derived from the ln α vs. 1/T curves in the studied temperature range (10–50 °C. The values of the thermodynamic parameters depended on the nature of the selectors, the structures of the analytes, and the positions of the substituents on the analytes. A comparison of the zwitterionic stationary phases revealed that the quinidine-based ZWIX(−™ column exhibited much better selectivity for both β2- and β3-amino acids than the quinine-based ZWIX(+™ column, and the separation performances of both the ZWIX(+™ and ZWIX(−™ columns were better for β2-amino acids. The elution sequence was determined in some cases and was observed to be R < S and S < R on the ZWIX(+™ and ZWIX(−™ columns, respectively.

  12. Cinchona Alkaloid Derivatives Catalyzed Asymmetric Aza-Michael Addition Reaction%金鸡纳生物碱衍生物催化的不对称Aza-Michael加成反应

    Institute of Scientific and Technical Information of China (English)

    王黎明; 金瑛; 贾云宏

    2014-01-01

    将金鸡纳生物碱衍生物催化剂用于不同查尔酮和苯胺及其衍生物的不对称Aza-Michael加成反应,以65%~92%的化学产率和最高达81%e.e.的对映选择性得到R-构型加成产物.

  13. Drug: D07153 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available amily) Cinchona bark Major component: Quinine [CPD:C06526] Therapeutic category of drugs... in Japan [BR:br08301] 5 Crude drugs and Chinese medicine formulations 51 Crude drugs 510 Crude drugs 5100 Crude drugs D07153 Cinchona bark PubChem: 51091492 ...

  14. Colonial Agro-Industrialism : Science, Industry and the State in the Dutch Golden Alkaloid Age, 1850-1950

    NARCIS (Netherlands)

    Roersch van der Hoogte, A.

    2015-01-01

    This thesis is about what I call the Dutch Golden Alkaloid Age between roughly the 1850s and 1950s. I follow the historical trajectory of the production and distribution of the anti-febrifuge cinchona bark tree (Cinchona officinalis Lin.) and its most powerful and therapeutically applied alkaloid in

  15. Colonial Agro-Industrialism : Science, Industry and the State in the Dutch Golden Alkaloid Age, 1850-1950

    OpenAIRE

    Roersch van der Hoogte, A.

    2015-01-01

    This thesis is about what I call the Dutch Golden Alkaloid Age between roughly the 1850s and 1950s. I follow the historical trajectory of the production and distribution of the anti-febrifuge cinchona bark tree (Cinchona officinalis Lin.) and its most powerful and therapeutically applied alkaloid in the Dutch empire—quinine, an antimalarial medicine. During this period, scientists, planters, traders, industrialists and state officials in the Netherlands and the former Dutch colony of the Neth...

  16. Preparation of Mesoporous SBA-16 Silica-Supported Biscinchona Alkaloid Ligand for the Asymmetric Dihydroxylation of Olefins

    Directory of Open Access Journals (Sweden)

    Shaheen M. Sarkar

    2014-01-01

    Full Text Available Optically active cinchona alkaloid was anchored onto mesoporous SBA-16 silica and the as-prepared complex was used as a heterogeneous chiral ligand of osmium tetraoxide for the asymmetric dihydroxylation of olefins. The prepared catalytic system provided 90–93% yield of vicinal diol with 92–99% enantioselectivity. The ordered mesoporous SBA-16 silica was found to be a valuable support for the cinchona alkaloid liganded osmium catalyst system which is frequently used in chemical industries and research laboratories for olefin functionalization.

  17. Extraction of alkaloids for NMR-based profiling

    DEFF Research Database (Denmark)

    Yilmaz, Ali; Nyberg, Nils; Jaroszewski, Jerzy W.

    2012-01-01

    A museum collection of Cinchona cortex samples (n = 117), from the period 1850–1950, were extracted with a mixture of chloroform-d1, methanol-d4, water-d2, and perchloric acid in the ratios 5:5:1:1. The extracts were directly analyzed using 1H NMR spectroscopy (600 MHz) and the spectra evaluated ...

  18. Organocatalytic One-Pot Asymmetric Synthesis of Thiolated Spiro-γ-lactam Oxindoles Bearing Three Stereocenters.

    Science.gov (United States)

    Huang, Xin; Liu, Miao; Pham, Kenny; Zhang, Xiaofeng; Yi, Wen-Bin; Jasinski, Jerry P; Zhang, Wei

    2016-07-01

    The first asymmetric synthesis of spiro-γ-lactam oxindoles bearing three stereocenters is reported. One-pot thiol-Michael/Mannich/lactamization reactions promoted by a recyclable fluorous bifunctional cinchona alkaloid/thiourea organocatalyst afford products in moderate to good yields with up to 95% ee and 6:1 dr. PMID:27258150

  19. A preliminary investigation of anticholinesterase activity of some Iranian medicinal plants commonly used in traditional medicine

    OpenAIRE

    Jazayeri, Seyed Behzad; Amanlou, Arash; Ghanadian, Naghmeh; Pasalar, Parvin; Amanlou, Massoud

    2014-01-01

    Background The aim of this study was to evaluate acetylcholinesterase inhibitory activity of some commonly used herbal medicine in Iran to introduce a new source for management of Alzheimer’s disease. A total of 18 aqueous-methanolic extract (1:1; v/v) from the following plants: Brassica alba, Brassica nigra, Camellia sinensis, Cinchona officinalis, Citrus aurantifolia, Citrus x aurantium, Ferula assafoetida, Humulus lupulus, Juglans regia, Juniperus sabina, Myristica fragrans, Pelargonium gr...

  20. Enantioselective synthesis of 4H-pyranonaphthoquinones via sequential squaramide and silver catalysis.

    Science.gov (United States)

    Kaya, Uğur; Chauhan, Pankaj; Hack, Daniel; Deckers, Kristina; Puttreddy, Rakesh; Rissanen, Kari; Enders, Dieter

    2016-01-28

    An enantioselective one-pot Michael addition/hydroalkoxylation reaction between 2-hydroxy-1,4-naphthoquinones and alkyne-tethered nitroalkenes catalyzed by a cinchona-derived squaramide and a silver(I) salt has been developed. The sequential protocol provides a direct access to 4H-pyranonaphthoquinones in moderate to very good yields and good to excellent enantioselectivities at a very low catalyst loading (0.5 mol%) of the squaramide. PMID:26660230

  1. Acetylphosphonate as a Surrogate of Acetate or Acetamide in Organocatalyzed Enantioselective Aldol Reactions

    Science.gov (United States)

    Guang, Jie; Guo, Qunsheng

    2012-01-01

    Highly enantioselective aldol reactions of acetylphosphonates and activated carbonyl compounds was realized with cinchona alkaloid derived catalysts, in which the acetylphosphonate was directly used as an enolate precursor for the first time. The aldol product obtained was converted in situ to its corresponding ester or amide through methanolysis or aminolysis. The overall process may be viewed as formal highly enantioselective acetate or acetamide aldol reactions, which are very difficult to achieve directly with organocatalytic methods. PMID:22650245

  2. Templating effect in DNA proximity ligation enables use of non-bioorthogonal chemistry in biological fluids

    OpenAIRE

    Spiropulos, Nicholas G.; Heemstra, Jennifer M.

    2012-01-01

    Here we describe the first example of selective reductive amination in biological fluids using split aptamer proximity ligation (StAPL). Utilizing the cocaine split aptamer, we demonstrate small-molecule-dependent ligation that is dose-dependent over a wide range of target concentrations in buffer, human blood serum and artificial urine medium. We explore the substrate binding preferences of the split aptamer and find that the cinchona alkaloids quinine and quinidine bind to the aptamer with ...

  3. Highly enantio- and diastereoselective synthesis of β-methyl-γ- monofluoromethyl-substituted alcohols

    KAUST Repository

    Yang, Wenguo

    2011-06-07

    Enanatiopure β-methyl-γ-monofluoromethyl alcohols were prepared from the allylic alkylation between fluorobis(phenylsulfonyl)methane with Morita-Baylis-Hillman carbonates. The reaction was catalyzed by using the Cinchona alkaloid derivative, (DHQD)2AQN. The origin of the stereoselectivity was verified by DFT methods. Calculated geometries and relative energies of various transition states strongly support the observed stereoselectivity. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Enantioselective Synthesis of SNAP-7941: Chiral Dihydropyrimidone Inhibitor of MCH1-R

    OpenAIRE

    Goss, Jennifer M.; Schaus, Scott E.

    2008-01-01

    An enantioselective synthesis of SNAP-7941, a potent melanin concentrating hormone receptor antagonist, was achieved using two organocatalytic methods. The first method utilized to synthesize the enantioenriched dihydropyrimidone core was the Cinchona alkaloid-catalyzed Mannich reaction of β-keto esters to acyl imines and the second was chiral phosphoric acid-catalyzed Biginelli reaction. Completion of the synthesis was accomplished via selective urea formation at the N3 position of the dihyd...

  5. Screening for antimicrobial activity of ten medicinal plants used in Colombian folkloric medicine: A possible alternative in the treatment of non-nosocomial infections

    OpenAIRE

    Ocampo Saul A; Ochoa Veronica J; Rojas Jhon J; Muñoz John F

    2006-01-01

    Abstract Background The antimicrobial activity and Minimal Inhibitory Concentration (MIC) of the extracts of Bidens pilosa L., Bixa orellana L., Cecropia peltata L., Cinchona officinalis L., Gliricidia sepium H.B. & K, Jacaranda mimosifolia D.Don, Justicia secunda Vahl., Piper pulchrum C.DC, P. paniculata L. and Spilanthes americana Hieron were evaluated against five bacteria (Staphylococcus aureus, Streptococcus β hemolític, Bacillus cereus, Pseudomonas aeruginosa, and Escherichia coli), and...

  6. Antimalarial potential of homeopathic medicines against schizont maturation of Plasmodium berghei in short-term in vitro culture

    OpenAIRE

    Upma Bagai; Aswathy Rajan

    2012-01-01

    In vitro assessment of antimalarial drug susceptibility of Plasmodium has been a major research success, which has paved the way for the understanding of parasite and rapid screening of antimalarial drugs for their effectiveness. In the present study a preliminary screening to check the antiplasmodial activity of mother tincture (ϕ) and various potencies (6C, 30C, 200C) of homeopathic medicines Cinchona officinalis/china (Chin.), Chelidonium majus (Chel.) and Arsenicum album (Ars.) were done ...

  7. Highly enantio- and diastereoselective allylic alkylation of Morita-Baylis-Hillman carbonates with allyl ketones

    KAUST Repository

    Tong, Guanghu

    2013-05-17

    The asymmetric allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates with allyl ketones has been developed. The α-regioselective alkylation adducts, containing a hexa-1,5-diene framework with important synthetic value, were achieved in up to 83% yield, >99% ee, and 50:1 dr by using a commercially available Cinchona alkaloid as the catalyst. From the allylic alkylation adduct, a cyclohexene bearing two adjacent chiral centers was readily prepared. © 2013 American Chemical Society.

  8. Towards an asymmetric organocatalytic α-cyanation of β-ketoesters

    Science.gov (United States)

    Chowdhury, Raghunath; Schörgenhumer, Johannes; Novacek, Johanna; Waser, Mario

    2015-01-01

    This communication describes the first proof of concept for an asymmetric α-cyanation of β-ketoesters using a hypervalent iodine-based electrophilic cyanide-transfer reagent. A series of different organocatalysts has been investigated and it was found that the use of naturally occurring Cinchona alkaloids allows obtaining the target products in good yields and with moderate enantioselectivities up to er = 76:24 under operationally simple conditions. PMID:25843983

  9. Organocatalytic asymmetric addition of malonates to unsaturated 1,4-diketones

    Directory of Open Access Journals (Sweden)

    Sergei Žari

    2012-09-01

    Full Text Available The organocatalytic Michael addition of malonates to symmetric unsaturated 1,4-diketones catalyzed by thiourea and squaramide derivatives with Cinchona alkaloids afforded the formation of a new C–C bond in high yields (up to 98% and enantiomeric purities (up to 93%. The absolute configuration of the product was suggested from comparison of the experimental and calculated VCD spectra of the reaction product 3a.

  10. Substrate-controlled switchable asymmetric annulations to access polyheterocyclic skeletons.

    Science.gov (United States)

    Wang, Kai-Kai; Wang, Pan; Ouyang, Qin; Du, Wei; Chen, Ying-Chun

    2016-09-25

    An unexpected domino process from Morita-Baylis-Hillman carbonates of isatins and acrylate and α-cyano-α,β-unsaturated ketones to deliver highly enantioenriched tetrahydrofuro[2',3':4,5]pyrano[2,3-b]indoles catalysed by cinchona-derived tertiary amines, involving α-regioselective cyclopropanation, ring-opening, and ring-closure cascade reactions, was disclosed. In contrast, spirooxindoles incorporating a cyclopentene motif were produced through [3+2] annulations by employing Morita-Baylis-Hillman carbonates from isatins and acrylonitrile under similar catalytic conditions. Density functional theory calculations were conducted to elucidate the novel domino process and the switchable annulation reactions. PMID:27546091

  11. Quinine metabolism in man : Emphasis on the 3-hydroxylation as a biomarker reaction for the activity of CYP3A4

    OpenAIRE

    Mirghani, Rajaa A

    2002-01-01

    Quinine is one of the cinchona alkaloids and used in the treatment of severe forms of malaria. Formation of 3-hydroxyquinine is catalysed by cytochrome P-450 3A4 (CYP3A4), which is the enzyme involved in the metabolism of about 50% of all drugs in clinical use. In this thesis 1 investigated the relative importance of four metabolites of quinine in its metabolism in vitro and in vivo and studied the usefulness of the metabolic ratio (MR) of quinine (quinine/3- hydroxyquin...

  12. Direct asymmetric allylic alkenylation of N-itaconimides with Morita-Baylis-Hillman carbonates

    KAUST Repository

    Yang, Wenguo

    2012-08-03

    The asymmetric allylic alkenylation of Morita-Baylis-Hillman (MBH) carbonates with N-itaconimides as nucleophiles has been developed using a commercially available Cinchona alkaloid catalyst. A variety of multifunctional chiral α-methylene-β-maleimide esters were attained in moderate to excellent yields (up to 99%) and good to excellent enantioselectivities (up to 91% ee). The origin of the regio- and stereoselectivity was verified by DFT methods. Calculated geometries and relative energies of various transition states strongly support the observed regio- and enantioselectivity. © 2012 American Chemical Society.

  13. Isoindolinones as Michael Donors under Phase Transfer Catalysis: Enantioselective Synthesis of Phthalimidines Containing a Tetrasubstituted Carbon Stereocenter

    Directory of Open Access Journals (Sweden)

    Francesco Scorzelli

    2015-05-01

    Full Text Available Readily available chiral ammonium salts derived from cinchona alkaloids have proven to be effective phase transfer catalysts in the asymmetric Michael reaction of 3-substituted isoindolinones. This protocol provides a convenient method for the construction of valuable asymmetric 3,3-disubstituted isoindolinones in high yields and  moderate to good enantioselectivity. Diastereoselectivity was also investigated in the construction of contiguous tertiary and quaternary stereocenters. The use of acrolein as Michael acceptor led to an interesting tricyclic derivative, a pyrroloisoindolinone analogue, via a tandem conjugated addition/cyclization reaction.

  14. Primary amine/CSA ion pair: A powerful catalytic system for the asymmetric enamine catalysis

    KAUST Repository

    Liu, Chen

    2011-05-20

    A novel ion pair catalyst containing a chiral counteranion can be readily derived by simply mixing cinchona alkaloid-derived diamine with chiral camphorsulfonic acid (CSA). A mixture of 9-amino(9-deoxy)epi-quinine 8 and (-)-CSA was found to be the best catalyst with matching chirality, enabling the direct amination of α-branched aldehydes to proceed in quantitative yields and with nearly perfect enantioselectivities. A 0.5 mol % catalyst loading was sufficient to catalyze the reaction, and a gram scale enantioselective synthesis of biologically important α-methyl phenylglycine has been successfully demonstrated. © 2011 American Chemical Society.

  15. Molecular-level Design of Heterogeneous Chiral Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Gellman, Andrew John [Carnegie Mellon University; Sholl, David S. [Georgia Institute of Technology; Tysoe, Wilfred T. [University of Wisconsin - Milwaukee; Zaera, Francisco [University of California at Riverside

    2013-04-28

    ) modified by a variety of chiral templates. • Demonstrated enantioselective separation of racemic PO on chemically synthesized chiral gold nanoparticles. • Discovery of zwitterionic adsorption states of amino acids on Pd(111). • First structure determinations of adsorbed amino acids and identification of tetrameric chiral template structures. • Exploration of the enantiospecific interaction of PO and R-3-MCHO adsorption on chirally modified Cu(100), Cu(110) and Cu(111). One-to-One Interactions • Determination of cinchona orientation on Pt surfaces in situ at the solid-liquid interface using FT-IRAS. • Systematic study of the influence of solution properties on the adsorption of modified cinchonas alkaloids onto Pt surfaces. • Correlation of cinchona adsorption with catalytic activity, as affected by concentration, the nature of the solvent, and dissolved gases in the liquid phase. • Measurement of enantioselective chemisorption on 1-(1-naphthyl) ethylamine (NEA) modified Pt(111) and Pd(111) surfaces. • Imaging of chiral docking complexes between NEA and methyl pyruvate on Pd(111). Chiral Catalyst Synthesis • Anchoring of cinchona alkaloid to surfaces • Synthesis of chiral Au nanoparticles and demonstration of their enantiospecific interactions with R- and S-PO. • Elucidation of the driving forces for chiral imprinting of Cu(100) by L- and D-lysine to form Cu(3,1,17)R&S facets.

  16. Organocatalytic Asymmetric Conjugate Additions to Cyclopent-1-enecarbaldehyde: A Critical Assessment of Organocatalytic Approaches towards the Telaprevir Bicyclic Core.

    Science.gov (United States)

    Bernardi, Luca; Fochi, Mariafrancesca; Carbone, Riccardo; Martinelli, Ada; Fox, Martin E; Cobley, Christopher J; Kandagatla, Bhaskar; Oruganti, Srinivas; Dahanukar, Vilas H; Carlone, Armando

    2015-12-21

    In the context of a programme directed at the manufacture of telaprevir, eight possible approaches to its bicyclic α-amino acid core, based on organocatalytic enantioselective conjugate additions to cyclopent-1-enecarbaldehyde, were identified and preliminarily explored. Four reactions, delivering advanced intermediates en route to the target amino acid, were selected for a thorough optimisation. Three of this reactions involved iminium ion catalysis with a prolinol catalyst (addition of nitromethane, nitroacetate and acetamidomalonate) and one was based on a Cinchona-derived phase-transfer catalyst (addition of glycine imines). A careful choice of additives allowed lowering of the catalyst loading to 0.5 mol% in some cases. The preparation of intermediates that would give access to the core of telaprevir in good yields and enantioselectivities by exploiting readily available substrates and catalysts, highlights the potential of organocatalytic technology for a cost-effective preparation of pharmaceuticals. PMID:26602867

  17. Monitoring surface processes during heterogeneous asymmetric hydrogenation of ketones on a chirally modified platinum catalyst by operando spectroscopy.

    Science.gov (United States)

    Meemken, Fabian; Hungerbühler, Konrad; Baiker, Alfons

    2014-08-11

    Surface processes occurring at the catalytic chiral surface of a cinchona-modified Pt catalyst during the asymmetric hydrogenation of activated ketones have been monitored for the first time using operando ATR-IR spectroscopy. Fundamental information about this catalytic system could be gained, including the chiral modification process of the catalyst, the surface interaction of reactant ketone with preadsorbed chiral modifier, the role of hydrogen as well as the influence of the product enantiomers in the catalytic cycle. The formation of a diastereomeric transient surface complex between ketone and chiral modifier was found to be related to the ketone consumption. Among the studied activated ketones, a correlation between stereoselection and the strength of the intermolecular hydrogen bond was identified. Dissociated hydrogen from the catalytic surface is found to play a crucial role in the formation of the diastereomeric surface complex. PMID:24777839

  18. Improved traditional phytomedicines in current use for the clinical treatment of malaria.

    Science.gov (United States)

    Willcox, Merlin

    2011-04-01

    Phytomedicines and "green pharmacies" are promoted by some NGOs and governments as part of their efforts to control malaria. "Improved traditional medicines" (ITMs) are standardised as regards preparation and dose, although not always according to the concentration of active compounds. A systematic literature search revealed that six such phytomedicines are currently government-approved in at least one country and used on a relatively large scale nationally or internationally: Artemisia annua L. (Asteraceae), Cinchona bark (Rubiaceae), Cryptolepis sanguinolenta (Lindl.) Schltr. (Apocynaceae), "Ayush-64", "Malarial-5" and Cochlospermum planchonii Hook. f. ex Planch. (Bixaceae). One further ITM has been developed and is in the process of being approved: Argemone mexicana decoction. Their development, phytochemistry, pharmacology, and clinical trials are reviewed, as well as priorities for future research. PMID:21204042

  19. Tropical American plants in the treatment of infectious diseases.

    Science.gov (United States)

    Dvorkin-Camiel, Lana; Whelan, Julia S

    2008-01-01

    The increasingly diverse U.S. immigrant populations and the growing use of medicinal herbs create a need for health care professionals to expand their knowledge in this area. This is a review of tropical plants, Annona Muricata, Artemisia absinthium, Cinchona officinalis, Illicium verum, Momordica charantia, Opuntia streptacantha, Schinus terebinthifolius, and Tabebuia avellanedae (impetiginosa), commonly used by Latino and Haitian populations for the treatment of infectious disease. All the eight plants discussed here have one or more of the following: antibacterial, antiviral, antifungal, or antiparasitic properties. All of these plants are primarily known and used in the tropical region, but they are also readily available for purchase in the United States, specifically in the ethnic markets. This review discusses their traditional uses, chemical constituents, proven scientific evidence, and toxicities. PMID:22436096

  20. Direct asymmetric vinylogous Michael addition of cyclic enones to nitroalkenes via dienamine catalysis

    Science.gov (United States)

    Bencivenni, Giorgio; Galzerano, Patrizia; Mazzanti, Andrea; Bartoli, Giuseppe; Melchiorre, Paolo

    2010-01-01

    In spite of the many catalytic methodologies available for the asymmetric functionalization of carbonyl compounds at their α and β positions, little progress has been achieved in the enantioselective carbon–carbon bond formation γ to a carbonyl group. Here, we show that primary amine catalysis provides an efficient way to address this synthetic issue, promoting vinylogous nucleophilicity upon selective activation of unmodified cyclic α,β-unsaturated ketones. Specifically, we document the development of the unprecedented direct and vinylogous Michael addition of β-substituted cyclohexenone derivatives to nitroalkenes proceeding under dienamine catalysis. Besides enforcing high levels of diastereo- and enantioselectivity, chiral primary amine catalysts derived from natural cinchona alkaloids ensure complete γ-site selectivity: The resulting, highly functionalized vinylogous Michael adducts, having two stereocenters at the γ and δ positions, are synthesized with very high fidelity. Finally, we describe the extension of the dienamine catalysis-induced vinylogous nucleophilicity to the asymmetric γ-amination of cyclohexene carbaldehyde. PMID:20566884

  1. Tuning Aryl−CH···O Intermolecular Interactions on Pt(111)

    DEFF Research Database (Denmark)

    Demers-Carpentier, Vincent; Laliberte, Marc-André; Pan, Yunxiang;

    2010-01-01

    Scanning tunneling microscopy (STM) data are reported for the room-temperature adsorption of 2,2,2-trifluoroacetophenone (TFAP), 2,2,2-trifluorovinylbenzene (TFVB), octafluoroacetophenone (OFAP), and methyl benzoate (MB) on Pt(111). The objective of the study is to establish the role of aryl......−CH···O bonding as the driving force for dimer formation. In contrast to TFAP, chemisorbed TFVB and OFAP do not form such self-assembled structures as they lack carbonyl and aryl−CH groups, respectively. The self-assembly of MB on Pt(111) differs from that of TFAP, in that it can form structures stabilized by one......, as distinct from two, aryl−CH···O bonds. The results are discussed with respect to the enantioselective hydrogenation of α-ketoesters on cinchona modified Pt catalysts....

  2. Tuning Aryl−CH···O Intermolecular Interactions on Pt(111)

    DEFF Research Database (Denmark)

    Demers-Carpentier, Vincent; Laliberte, Marc-André; Pan, Yunxiang;

    2011-01-01

    Scanning tunneling microscopy (STM) data are reported for the room-temperature adsorption of 2,2,2-trifluoroacetophenone (TFAP), 2,2,2-trifluorovinylbenzene (TFVB), octafluoroacetophenone (OFAP), and methyl benzoate (MB) on Pt(111). The objective of the study is to establish the role of aryl......−CH···O bonding as the driving force for dimer formation. In contrast to TFAP, chemisorbed TFVB and OFAP do not form such self-assembled structures as they lack carbonyl and aryl−CH groups, respectively. The self-assembly of MB on Pt(111) differs from that of TFAP, in that it can form structures stabilized by one......, as distinct from two, aryl−CH···O bonds. The results are discussed with respect to the enantioselective hydrogenation of α-ketoesters on cinchona modified Pt catalysts....

  3. [Historical notes on the therapy of depression].

    Science.gov (United States)

    Haenel, T

    1986-11-22

    Melancholy originally had another meaning from the present one. Only since the last century has melancholy taken on the meaning of severe depression. The Arabs were the first to introduce special wards for the mentally ill in their hospitals in the 8th and 9th centuries. In the West, mental wards in general hospitals have been known since the 13th century only. In the Renaissance dietary measures played an important part in the treatment of depression. Lean meat, fresh eggs, freshwater fish and particularly grapes were recommended. In the 17th and 18th centuries music therapy against depression came back into favour after being used in ancient times. In the 19th century opium was recommended and held its ground well into the middle of our century. Various methods and drugs were recommended and used for the therapy of depression in the 19th century, such as baths and massage, ferrous iodide, arsenic, ergot, strophantin, and cinchona. Actual antidepressants have been known only for approximately 30 years. The classic papers concerning therapy with lithium salts date back to the years 1948/49. It is a little known fact, however, that lithium salts had been used as prophylactic treatment against periodic depression 50 years earlier. PMID:3541174

  4. The Stereoselective Epoxidation by a New Type of Soluble Polymer-Supported Catalysts

    Institute of Scientific and Technical Information of China (English)

    Wang Yongmei; Wang Xin; Liu Juyan

    2004-01-01

    As the phase transfer catalyst (PTC) is one of most important catalysts in organic synthesis. Here, we represent initial results of a research program aimed at the rational design of a variety of new two centers, soluble polyethylene glycol (PEG) supported catalysts based on the cinchona alkaloid system and their application in asymmetric expoxidation process.Table 1 and Table 2 summarized the results of epoxidation of substituted chalcone As shown in Table 1 and Table 2, chalcone derivatives as reactive olefins afforded the corresponding epoxided with modest to good enantiomeric excesses. In contrast, a definite trend to higher ee value is displayed by solvent effect. It was found that enantioselectivity becomes higher with the polarity increases(Table 1, Table 2). Changing catalyst 1 to catalyst 2, ee value was increased (entry 6 in Table 1) as well. Compared with Me, NO2 groups, substitution on the aromatic ring of the enone carbonyl function by OMe group increased the enantioselectivity(entry 3 in Table 1 and entry 3' in Table 2).

  5. Enantioselective Organocatalyzed Synthesis of 2-Amino-3-cyano-4H-chromene Derivatives

    Directory of Open Access Journals (Sweden)

    Isaac G. Sonsona

    2015-08-01

    Full Text Available The structural motif that results from the fusion of a benzene ring to a heterocyclic pyran ring, known as chromene, is broadly found in nature and it has been reported to be associated with a wide range of biological activity. Moreover, asymmetric organocatalysis is a discipline in expansion that is already recognized as a well-established tool for obtaining enantiomerically enriched compounds. This review covers the particular case of the asymmetric synthesis of 2-amino-3-cyano-4H-chromenes using organocatalysis. Herein, we show the most illustrative examples of the methods developed by diverse research groups, following a classification based on these five different approaches: (1 addition of naphthol compounds to substituted α,α-dicyanoolefins; (2 addition of malononitrile to substituted o-vinylphenols; (3 addition of malononitrile to N-protected o-iminophenols; (4 Michael addition of nucleophiles to 2-iminochromene derivatives; and (5 organocatalyzed formal [4+2] cycloaddition reaction. In most cases, chiral thioureas have been found to be effective catalysts to promote the synthetic processes, and generally a bifunctional mode of action has been envisioned for them. In addition, squaramides and cinchona derivatives have been occasionally used as suitable catalysts for the substrates activation.

  6. Templating effect in DNA proximity ligation enables use of non-bioorthogonal chemistry in biological fluids.

    Science.gov (United States)

    Spiropulos, Nicholas G; Heemstra, Jennifer M

    2012-07-01

    Here we describe the first example of selective reductive amination in biological fluids using split aptamer proximity ligation (StAPL). Utilizing the cocaine split aptamer, we demonstrate small-molecule-dependent ligation that is dose-dependent over a wide range of target concentrations in buffer, human blood serum and artificial urine medium. We explore the substrate binding preferences of the split aptamer and find that the cinchona alkaloids quinine and quinidine bind to the aptamer with higher affinity than cocaine. This increased affinity leads to improved detection limits for these small-molecule targets. We also demonstrate that linker length and hydrophobicity impact the efficiency of split aptamer ligation. The ability to carry out selective chemical transformations using non-bioorthogonal chemistry in media where competing reactive groups are present highlights the power of the increased effective molarity provided by DNA assembly. Obviating the need for bioorthogonal chemistry would dramatically expand the repertoire of chemical transformations available for use in templated reactions such as proximity ligation assays, in turn enabling the development of novel methods for biomolecule detection. PMID:23370267

  7. Amazonian Plant Natural Products: Perspectives for Discovery of New Antimalarial Drug Leads

    Directory of Open Access Journals (Sweden)

    Lucio H. Freitas-Junior

    2013-08-01

    Full Text Available Plasmodium falciparum and P. vivax malaria parasites are now resistant, or showing signs of resistance, to most drugs used in therapy. Novel chemical entities that exhibit new mechanisms of antiplasmodial action are needed. New antimalarials that block transmission of Plasmodium spp. from humans to Anopheles mosquito vectors are key to malaria eradication efforts. Although P. vivax causes a considerable number of malaria cases, its importance has for long been neglected. Vivax malaria can cause severe manifestations and death; hence there is a need for P. vivax-directed research. Plants used in traditional medicine, namely Artemisia annua and Cinchona spp. are the sources of the antimalarial natural products artemisinin and quinine, respectively. Based on these compounds, semi-synthetic artemisinin-derivatives and synthetic quinoline antimalarials have been developed and are the most important drugs in the current therapeutic arsenal for combating malaria. In the Amazon region, where P. vivax predominates, there is a local tradition of using plant-derived preparations to treat malaria. Here, we review the current P. falciparum and P. vivax drug-sensitivity assays, focusing on challenges and perspectives of drug discovery for P. vivax, including tests against hypnozoites. We also present the latest findings of our group and others on the antiplasmodial and antimalarial chemical components from Amazonian plants that may be potential drug leads against malaria.

  8. Zwitterionic phosphorylated quinines as chiral solvating agents for NMR spectroscopy.

    Science.gov (United States)

    Rudzińska-Szostak, Ewa; Górecki, Łukasz; Berlicki, Łukasz; Ślepokura, Katarzyna; Mucha, Artur

    2015-10-01

    Because of their unique 3D arrangement, naturally occurring Cinchona alkaloids and their synthetic derivatives have found wide-ranging applications in chiral recognition. Recently, we determined the enantioselective properties of C-9-phosphate mixed triesters of quinine as versatile chiral solvating agents in nuclear magnetic resonance (NMR) spectroscopy. In the current study, we introduce new zwitterionic members of this class of molecules containing a negatively charged phosphate moiety (i.e., ethyl, n-butyl and phenyl hydrogen quininyl phosphate). An efficient approach for synthesizing these compounds is elaborated, and full characterization, including conformational and autoaggregation phenomena studies, was performed. Therefore, their ability to induce NMR anisochrony of selected enantiomeric substrates (i.e., primarily N-DNB-protected amino acids and their methyl esters) was analyzed compared to uncharged diphenyl quininyl phosphate and its positively charged quaternary ammonium hydrochloride salt. In addition, (1) H and (13) C NMR experiments revealed their enantiodiscrimination potential toward novel analytes, such as secondary amines and nonprotected amino acids. PMID:26415853

  9. Some Topics in Relation to José Celestino Mutis and Medicine

    Directory of Open Access Journals (Sweden)

    Leonardo Palacios Sánchez

    2008-07-01

    Full Text Available José Celestino Mutis showed different interestareas of study and worked in multipleknowledge fields: mathematics, mineralogy, astronomy,zoology and botanic, the one in whichis best known. However, he was a medical doctor,whit profound an up to date knowledge. Hestudied at Sevilla University, and in the RoyalCollege of Cadiz. He arrived to the “NuevoReino de Granada” as personal medical doctorof the the viceroy Pedro Messía de la Cerda andduring 47 years, period of time he lived there,he always exercised his profession. We showeda special interest in the study of cinchona andthe only work he published was El Arcano dela quina. He advised in public health manyviceroys and he contributed in different fieldsbut particularly in the prevention of smallpoxby inoculation. He played a decisive role in thereopening of the medical school of the ColegioMayor de Nuestra Señora del Rosario. Someof his achievements justifies the appellative“Father of the Medicine in Colombia”.

  10. Separation of drug stereoisomers by the formation of. beta. -cyclodextrin inclusion complexes

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, D.W.; Ward, T.J.; Armstrong, R.D.; Beesley, T.E.

    1986-05-30

    For many drugs, only racemic mixtures are available for clinical use. Because different stereoisomers of drugs often cause different physiological responses, the use of pure isomers could elicit more exact therapeutic effects. Differential complexation of a variety of drug stereoisomers by immobilized ..beta..-cyclodextrin was investigated. Chiral recognition and racemic resolution were observed with a number of compounds from such clinically useful classes as ..beta..-blockers, calcium-channel blockers, sedative hypnotics, antihistamines, anticonvulsants, diuretics, and synthetic opiates. Separation of the diastereomers of the cardioactive and antimalarial cinchona alkaloids and of two antiestrogens was demonstrated as well. Three dimensional projections of ..beta..-cyclodextrin complexes of propanol, which is resolved by this technique, and warfarin, which is not, are compared. These studies have improved the understanding and application of the chiral interactions of ..beta..-cyclodextrin, and they have demonstrated a means to measure optical purity and to isolate or produce pure enantiomers of drugs. In addition, this highly specific technique could also be used in the pharmacological evaluation of enantiometric drugs. 27 references, 3 figures, 2 tables.

  11. Plants from Abroad: Botanical Terminology in 18th-century British Encyclopaedias

    Directory of Open Access Journals (Sweden)

    Elisabetta Lonati

    2013-11-01

    Full Text Available During the 18th century British encyclopaedias included in their lemmata an increasing number of botanical lexis, that is the terminology pertaining to “that branch of natural history which treats of the uses, characters, classes, orders, genera, and species of plants. […] and what useful and ornamental purposes may be expected from the cultivation of it [i.e. botany]” (Encyclopaedia Britannica, 1768-1771, s.v. Botany. More often than not, these terms represented migrating plants coming from exotic places, new geographical areas, whether eastwards or westwards.The general aim of this survey is to investigate the representation of the botanical science in 18th-century universal and specialized encyclopaedias, starting from prefaces and going on with the micro-texts of the single entries s.v. Botany. The starting point is thus theoretical botany. A further point in the analysis focuses on applied botany and discusses those plants such as Camellia Sinensis, Coffea Arabica, Theobroma Cacao, Saccharum Officinarum and Cinchona Officinalis which were mostly exploited for commercial and/or medical reasons.The individual entries include the most tiny details on the single headwords-topics and also display an acceptable plurality of beliefs, viewpoints and perspectives, focussing on botanical descriptions, historical information, socio-cultural issues, legal, political and commercial considerations.

  12. Antimalarial potential of homeopathic medicines against schizont maturation of Plasmodium berghei in short-term in vitro culture

    Directory of Open Access Journals (Sweden)

    Upma Bagai

    2012-12-01

    Full Text Available In vitro assessment of antimalarial drug susceptibility of Plasmodium has been a major research success, which has paved the way for the understanding of parasite and rapid screening of antimalarial drugs for their effectiveness. In the present study a preliminary screening to check the antiplasmodial activity of mother tincture (ϕ and various potencies (6C, 30C, 200C of homeopathic medicines Cinchona officinalis/china (Chin., Chelidonium majus (Chel. and Arsenicum album (Ars. were done by assessing the in vitro schizont maturation inhibition assay. A significant reduction in the growth of intraerythrocytic stages of P. berghei was observed with decreasing dilution of ϕ and various potencies of Chin., Chel. and Ars. exhibiting a dose dependent effect. Maximum schizont maturation inhibition was observed by Chin. ϕ (1:1, Chin. 30 (1:1, 1:2 and Chel. 30 (1:1 i.e. 80%. The standard drug CQ at 10 µM concentration exhibited 95.4±1.6% inhibition of schizont maturation. Ars. 30 (1:1 also have been found to possess strong antiplasmodial efficacy with 75.5±2.6% schizont inhibition. The presence of free merozoites in Ars. 200 with weak schizonticidal inhibition activity (40-45% also pointed towards the ability of parasite to survive in the given drug pressure.

  13. Organocatalysis: Fundamentals and Comparisons to Metal and Enzyme Catalysis

    Directory of Open Access Journals (Sweden)

    Pierre Vogel

    2016-08-01

    Full Text Available Catalysis fulfills the promise that high-yielding chemical transformations will require little energy and produce no toxic waste. This message is carried by the study of the evolution of molecular catalysis of some of the most important reactions in organic chemistry. After reviewing the conceptual underpinnings of catalysis, we discuss the applications of different catalysts according to the mechanism of the reactions that they catalyze, including acyl group transfers, nucleophilic additions and substitutions, and C–C bond forming reactions that employ umpolung by nucleophilic additions to C=O and C=C double bonds. We highlight the utility of a broad range of organocatalysts other than compounds based on proline, the cinchona alkaloids and binaphthyls, which have been abundantly reviewed elsewhere. The focus is on organocatalysts, although a few examples employing metal complexes and enzymes are also included due to their significance. Classical Brønsted acids have evolved into electrophilic hands, the fingers of which are hydrogen donors (like enzymes or other electrophilic moieties. Classical Lewis base catalysts have evolved into tridimensional, chiral nucleophiles that are N- (e.g., tertiary amines, P- (e.g., tertiary phosphines and C-nucleophiles (e.g., N-heterocyclic carbenes. Many efficient organocatalysts bear electrophilic and nucleophilic moieties that interact simultaneously or not with both the electrophilic and nucleophilic reactants. A detailed understanding of the reaction mechanisms permits the design of better catalysts. Their construction represents a molecular science in itself, suggesting that sooner or later chemists will not only imitate Nature but be able to catalyze a much wider range of reactions with high chemo-, regio-, stereo- and enantioselectivity. Man-made organocatalysts are much smaller, cheaper and more stable than enzymes.

  14. Whole plant extracts versus single compounds for the treatment of malaria: synergy and positive interactions

    Directory of Open Access Journals (Sweden)

    Wright Colin W

    2011-03-01

    Full Text Available Abstract Background In traditional medicine whole plants or mixtures of plants are used rather than isolated compounds. There is evidence that crude plant extracts often have greater in vitro or/and in vivo antiplasmodial activity than isolated constituents at an equivalent dose. The aim of this paper is to review positive interactions between components of whole plant extracts, which may explain this. Methods Narrative review. Results There is evidence for several different types of positive interactions between different components of medicinal plants used in the treatment of malaria. Pharmacodynamic synergy has been demonstrated between the Cinchona alkaloids and between various plant extracts traditionally combined. Pharmacokinetic interactions occur, for example between constituents of Artemisia annua tea so that its artemisinin is more rapidly absorbed than the pure drug. Some plant extracts may have an immunomodulatory effect as well as a direct antiplasmodial effect. Several extracts contain multidrug resistance inhibitors, although none of these has been tested clinically in malaria. Some plant constituents are added mainly to attenuate the side-effects of others, for example ginger to prevent nausea. Conclusions More clinical research is needed on all types of interaction between plant constituents. This could include clinical trials of combinations of pure compounds (such as artemisinin + curcumin + piperine and of combinations of herbal remedies (such as Artemisia annua leaves + Curcuma longa root + Piper nigum seeds. The former may enhance the activity of existing pharmaceutical preparations, and the latter may improve the effectiveness of existing herbal remedies for use in remote areas where modern drugs are unavailable.

  15. Organocatalytic Asymmetric Michael Additions%有机催化不对称Michael加成反应

    Institute of Scientific and Technical Information of China (English)

    李宁; 郗国宏; 吴秋华; 刘伟华; 马晶军; 王春

    2009-01-01

    有机催化的不对称合成反应是目前研究最为活跃的领域之一.不对称Michael加成反应是合成众多重要的手性合成子和药物中间体的有效手段.目前报道的催化Michael加成反应的有机催化剂主要有脯氨酸及其衍生物、手性咪唑啉酮、手性(硫)脲、金鸡纳碱衍生物等.对各类有机催化剂在有机催化不对称Michael加成反应中的应用,以及不对称诱导反应的机理、催化剂分子结构及反应条件对其催化活性和不对称诱导作用的影响进行了评述.%Organocatalytic asymmetric reaction is an increasingly active area in organic synthesis. The asymmetric Michael addition provides a rapid access to versatile important chiral building blocks and intermediates for the synthesis of bioactive agrochemicals and pharmaceutical compounds. The reported organocatalysts for asymmetric Michael additions include proline and its derivatives, chiral imidazolidinone derivatives, chiral (thio) urea, cinchona alkaloids and so on. The applications of various organocatalysts to asymmetric Michael additions are reviewed in this paper. The reaction mechanism, catalytic activity and the asymmetric induction influenced by the structure of organocatalysts and the reaction condition are also discussed.

  16. Transits of Venus and Colonial India

    Science.gov (United States)

    Kochhar, Rajesh

    2012-09-01

    Astronomical expeditions during the colonial period had a political and national significance also. Measuring the earth and mapping the sky were activities worthy of powerful and power- seeking nations. Such was the sanctity of global astronomical activity that many other agendas could be hidden under it. An early astronomy-related expedition turned out to be extremely beneficial, to botany. The expedition sent by the French Government in 1735 to South America under the leadership of Charles Marie de la Condamine (1701--1774) ostensibly for the measurement of an arc of the meridian at Quito in Ecuador surreptitiously collected data that enabled Linnaeus to describe the genus cinchona in 1742. When the pair of transits of Venus occurred in 1761 and 1769, France and England were engaged in a bitter rivalry for control of India. The observation of the transits became a part of the rivalry. A telescope presented by the British to a South Indian King as a decorative toy was borrowed back for actual use. Scientifically the transit observations were a wash out, but the exercise introduced Europe to details of living Indian tradition of eclipse calculations. More significantly, it led to the institutionalization of modern astronomy in India under the auspices of the English East India Company (1787). The transits of Venus of 1874 and 1882 were important not so much for the study of the events as for initiating systematic photography of the Sun. By this, Britain owned most of the world's sunshine, and was expected to help European solar physicists get data from its vast Empire on a regular basis. This and the then genuinely held belief that a study of the sun would help predict failure of monsoons led to the institutionalization of solar physics studies in India (1899). Of course, when the solar physicists learnt that solar activity did not quite determine rainfall in India, they forgot to inform the Government.

  17. Antimalarial potential of China 30 and Chelidonium 30 in combination therapy against lethal rodent malaria parasite: Plasmodium berghei.

    Science.gov (United States)

    Rajan, Aswathy; Bagai, Upma

    2013-01-01

    Homeopathy is a therapeutic method based on the application of similia principle, utilizing ultra-low doses of medicinal substances made from natural products. The present study has been designed to evaluate the efficacy of Cinchona officinalis (Chin.) 30C and Chelidonium majus (Chel.) 30C in combination therapy against lethal murine malaria. Five groups having twelve BALB/c mice each were administered orally with 0.2 ml/mouse/day of different drugs, and their antimalarial potential was evaluated by Peter's 4-day test. The combination of Chin. 30 and Chel. 30 exhibited complete parasite clearance by the 28th day post-inoculation which was similar to the positive control [artesunate (4 mg/kg)+sulphadoxine-primethamine (1.2 mg/kg)] group. Both the groups exhibited enhanced mean survival time (MST) 28±0 days,whereas, the mice of infected control group survived up to 7.6±0.4 days only. The preventive and curative activities of the combination in comparison to the positive controls [pyrimethamine (1.2 mg/Kg) and chloroquine (20 mg/Kg), respectively] were also evaluated. The combination had a significant preventive activity (p<0.0005), with 89.2% chemosuppression which was higher than the standard drug, pyrimethamine (83.8%). It also showed a moderate curative activity with complete clearance of parasite in 50% of surviving mice, and enhancing the MST of mice up to 26.8±2.8 days. These findings point to the significant antiplasmodial efficacy of the combination of these homeopathic drugs against Plasmodium berghei. PMID:23652641

  18. Medicinal plants, human health and biodiversity: a broad review.

    Science.gov (United States)

    Sen, Tuhinadri; Samanta, Samir Kumar

    2015-01-01

    Biodiversity contributes significantly towards human livelihood and development and thus plays a predominant role in the well being of the global population. According to WHO reports, around 80 % of the global population still relies on botanical drugs; today several medicines owe their origin to medicinal plants. Natural substances have long served as sources of therapeutic drugs, where drugs including digitalis (from foxglove), ergotamine (from contaminated rye), quinine (from cinchona), and salicylates (willow bark) can be cited as some classical examples.Drug discovery from natural sources involve a multifaceted approach combining botanical, phytochemical, biological, and molecular techniques. Accordingly, medicinal-plant-based drug discovery still remains an important area, hitherto unexplored, where a systematic search may definitely provide important leads against various pharmacological targets.Ironically, the potential benefits of plant-based medicines have led to unscientific exploitation of the natural resources, a phenomenon that is being observed globally. This decline in biodiversity is largely the result of the rise in the global population, rapid and sometimes unplanned industrialization, indiscriminate deforestation, overexploitation of natural resources, pollution, and finally global climate change.Therefore, it is of utmost importance that plant biodiversity be preserved, to provide future structural diversity and lead compounds for the sustainable development of human civilization at large. This becomes even more important for developing nations, where well-planned bioprospecting coupled with nondestructive commercialization could help in the conservation of biodiversity, ultimately benefiting mankind in the long run.Based on these findings, the present review is an attempt to update our knowledge about the diverse therapeutic application of different plant products against various pharmacological targets including cancer, human brain

  19. Five prevalent antiprotozoal herbal drugs

    Directory of Open Access Journals (Sweden)

    Mohammad Azadbakht1

    2008-01-01

    Full Text Available , (Received 21 Jun, 2008 ; Accepted 12 Nov, 2008 AbstractAccording to the statistics provided by the World Health Organization (WHO, about 80% of the world population nowadays uses herbal drugs for treatment of diseases. Natural products obtained from medicinal plants, serve as a great source for drug production and are the main basis of new drug compounds. Unicellular organisms (Protozoa are the cause of deaths and spread of diseases in various societies, especially in developing countries. There are anti-malaria herbal dugs produced from various medicinal plants, some of which are used for treatment of the disease and some under study. The first anti-malaria drug was quinine, produced from bark of the Cinchona tree. Recently, the drug artemisinin has been introduced by Chinese scientists for the treatment of malaria and is currently used extensively. Coetaneous leishmaniosis (salak is one of the endemic diseases in most parts of Iran. Common drugs used against leishmaniosis (such as glucantim, have severe side-effects and in 10 to 25% of cases, there is a recurrence of the disease. Emetine is one of the drugs obtained from a root of the plant Ipecac, which is used for treatment of the disease sub-cutaneously. Giardiasis is an acute protozoan infection usually with no clinical symptoms, however, may appear as acute or chronic diarrhea. According to the announcement of WHO, more than 2/3 of the world’s population is infected with intestinal parasites and the prevalence of giardia is higher than other intestinal parasites. Herbal drugs, such as wild garlic, eucalyptus and thyme, are some of the major plants which can annihilate the giarda cysts. Annually, 75000 to 100000 people die of amebiasis (dysentery worldwide. Due to the motility of the organism, it causes sever pathological changes and sometimes colon ulcers, and if entered into the blood stream, it may appear as liver or brain abscess. Medicinal plants such as ipecac, mango, and papaya

  20. [Alexandre Yersin (1863-1943), explorer and a founding scientist of the Pasteur Institutes].

    Science.gov (United States)

    Milleliri, J M

    2014-01-01

    2013 was the year to celebrate Yersin: the 150th anniversary of his birth and the 70th anniversary of his death. Beyond the images usually attached to the memory of this doctor who discovered the bubonic plague bacillus (in Hong Kong in 1894), the author seeks to introduce Yersin, the man, as an explorer curious about his environment rather than a scientist concerned with honors and public recognition. Alexandre Yersin is an atypical figure in the universe of Pasteur, his collaborators, students, and followers. Although he began his career working with Louis Pasteur following the development of the vaccine against rabies, in 1885, the call of the sea led him to quit the laboratory on rue Ulm to, he said, "explore new lands". He worked for the Messageries maritimes merchant shipping company. In Saigon, he met Albert Calmette, who convinced him to join the newly created Colonial Army Medical Corps. In 1892 in Nha-Trang, Yersin set up a bacteriology laboratory in a straw hut; it subsequently became the first Pasteur Institute in Indochina, the starting point of a network of research laboratories. During the bubonic plague epidemic that raged in Hong Kong, Yersin succeeded in isolating its causal agent, surprising even himself by the ease with which he did so. He was 30 years old then, but what could have been the start of a prestigious career, crowned with honors, was spent instead at the service of the local populations. His exploration of the Vietnam highlands gave Yersin the occasion to cultivate and reveal a prodigious eclecticism and his profound humanism. He led three explorations in unknown regions of Annam and contributed to the development of this country by his social, educational, medical, and economic approach, entirely dedicated to aiding the indigenous populations. Yersin never left Vietnam again. He worked as an astronomer and agronomist (introducing the cultivation of cinchona (source of quinine) and rubber trees in the country) - always close to the

  1. Drug-induced immune thrombocytopenia.

    Science.gov (United States)

    van den Bemt, Patricia M L A; Meyboom, Ronald H B; Egberts, Antoine C G

    2004-01-01

    Thrombocytopenia can have several causes, including the use of certain drugs. The mechanism behind drug-induced thrombocytopenia is either a decrease in platelet production (bone marrow toxicity) or an increased destruction (immune-mediated thrombocytopenia). In addition, pseudothrombocytopenia, an in vitro effect, has to be distinguished from true drug-induced thrombocytopenia. This article reviews literature on drug-induced immune thrombocytopenia, with the exception of thrombo-haemorrhagic disorders such as thrombotic thrombocytopenic purpura and heparin-induced thrombocytopenia and thrombosis. A literature search in PubMed combined with a check of the reference lists of all the retrieved articles resulted in 108 articles relevant to the subject. The drug classes that are most often associated with drug-induced immune thrombocytopenia are cinchona alkaloid derivatives (quinine, quinidine), sulfonamides, NSAIDs, anticonvulsants, disease modifying antirheumatic drugs and diuretics. Several other drugs are occasionally described in case reports of thrombocytopenia; an updated review of these case reports can be found on the internet. A small number of epidemiological studies, differing largely in the methodology used, describe incidences in the magnitude of 10 cases per 1 000 000 inhabitants per year. No clear risk factors could be identified from these studies. The underlying mechanism of drug-induced immune thrombocytopenia is not completely clarified, but at least three different types of antibodies appear to play a role (hapten-dependent antibodies, drug-induced, platelet-reactive auto-antibodies and drug-dependent antibodies). Targets for drug-dependent antibodies are glycoproteins on the cell membrane of the platelets, such as glycoprotein (GP) Ib/IX and GPIIb/IIIa. Diagnosis of drug-induced immune thrombocytopenia may consist of identifying clinical symptoms (bruising, petechiae, bleeding), a careful evaluation of the causal relationship of the suspected

  2. Bosques montanos-relictos en Kañaris (Lambayeque, Perú

    Directory of Open Access Journals (Sweden)

    Santos Llatas-Quiroz

    2013-05-01

    Full Text Available En Kañaris (Lambayeque se encuentran grandes bosques relictos, probablemente los mayores de la vertiente occidental de los Andes peruanos. Actualmente están muy bien conservados, pero al mismo tiempo es la zona botánicamente menos estudiada de todos los bosques relictos de la zona. Estos bosques se ubican en las alturas de Upaypiteq y adyacentes a los flancos de la cordillera occidental de los Andes en la vertiente del Atlántico: Shin Shin, San Lorenzo, Huacapampa, Pandachí, Gramalote, Walte, Mollepampa; entre los 1500 a 3000 m sobre el nivel del mar, en el distrito de Kañaris (2300 m y los bosques de Chiñama y Luto en la vertiente del Pacífico. La presente investigación se emprendió con el objeto de estudiar científicamente, mediante muestreos florísticos, la vida y estructura de los componentes de los bosques de Upaypiteq. Las muestras conducen a un avance de la investigación, determinando que los principales componentes arbóreos corresponden a las Lauráceas: Persea, Ocotea y Nectandra, Cunoniáceas: Weinmannia, Podocarpáceas: Podocarpus, Cecropiáceas: Cecropia, Mirtáceas: Myrcianthes, Moráceas: Ficus, Rubiáceas: Cinchona, Bignoniáceas: Tabebuia, Arecáceas: Ceroxylon y, helechos arborescentes del género Nephelea. Circundantes a la masa boscosa se encuentran varias especies de arbustos, de los géneros Miconia, Munnozia, Baccharis, Senna, Colignonia, Gaiadendron, Oreopanax, etc.; también en la estructura es muy frecuente las epífitas y lianas ascendentes: Bromeliáceas, Orquídeas, Heliconias, Aráceas, musgos. Los helechos herbáceos, hongos, líquenes gelatinosos, hepáticas, Balanoforáceas y Begonias, tapizan por completo el piso boscoso. La composición florística es similar al bosque de Cutervo y los bosques de la Vertiente Oriental de los Andes, que a los demás bosques relictos en la Vertiente Occidental. La presencia de estos bosques se debe preservar, por su importancia en los procesos ecológicos para la

  3. Screening for antimicrobial activity of ten medicinal plants used in Colombian folkloric medicine: A possible alternative in the treatment of non-nosocomial infections

    Directory of Open Access Journals (Sweden)

    Ocampo Saul A

    2006-02-01

    Full Text Available Abstract Background The antimicrobial activity and Minimal Inhibitory Concentration (MIC of the extracts of Bidens pilosa L., Bixa orellana L., Cecropia peltata L., Cinchona officinalis L., Gliricidia sepium H.B. & K, Jacaranda mimosifolia D.Don, Justicia secunda Vahl., Piper pulchrum C.DC, P. paniculata L. and Spilanthes americana Hieron were evaluated against five bacteria (Staphylococcus aureus, Streptococcus β hemolític, Bacillus cereus, Pseudomonas aeruginosa, and Escherichia coli, and one yeast (Candida albicans. These plants are used in Colombian folk medicine to treat infections of microbial origin. Methods Plants were collected by farmers and traditional healers. The ethanol, hexane and water extracts were obtained by standard methods. The antimicrobial activity was found by using a modified agar well diffusion method. All microorganisms were obtained from the American Type Culture Collection (ATCC. MIC was determined in the plant extracts that showed some efficacy against the tested microorganisms. Gentamycin sulfate (1.0 μg/ml, clindamycin (0.3 μg/ml and nystatin (1.0 μg/ml were used as positive controls. Results The water extracts of Bidens pilosa L., Jacaranda mimosifolia D.Don, and Piper pulchrum C.DC showed a higher activity against Bacillus cereus and Escherichia coli than gentamycin sulfate. Similarly, the ethanol extracts of all species were active against Staphylococcus aureus except for Justicia secunda. Furthermore, Bixa orellana L, Justicia secunda Vahl. and Piper pulchrum C.DC presented the lowest MICs against Escherichia coli (0.8, 0.6 and 0.6 μg/ml, respectively compared to gentamycin sulfate (0.9 8g/ml. Likewise, Justicia secunda and Piper pulchrum C.DC showed an analogous MIC against Candida albicans (0.5 and 0.6 μg/ml, respectively compared to nystatin (0.6 μg/ml. Bixa orellana L, exhibited a better MIC against Bacillus cereus (0.2 μg/ml than gentamycin sulfate (0.5 μg/ml. Conclusion This in vitro study

  4. Utilization of N-X bonds in the synthesis of N-heterocycles.

    Science.gov (United States)

    Minakata, Satoshi

    2009-08-18

    -deficient olefins in the presence of a phase transfer catalyst to give the corresponding aziridines. We also used this method to synthesize asymmetric aziridines using quaternary cinchona alkaloid catalysts. We also developed a facile synthetic method for preparing N-heterocycles that involves the in situ generation of an N-X bond using tert-butyl hypochlorite or tert-butyl hypoiodite (tert-BuOI). Treatment of alkenylamides containing an active hydrogen on the nitrogen with tert-BuOI led to the production of various N-heterocycles via intramolecular cyclization. Iodination of readily available sulfonamides or carboxamides with tert-BuOI generated reactive N-iodinated amides, which smoothly reacted with olefins to give aziridines or oxazolines. The reaction of fullerene, C(60), with CT also led to aziridination: the resulting aziridinofullerene underwent a unique rearrangement to an azafulleroid. Chlorination of readily available amide derivatives with tert-BuOCl, followed by a reaction with C(60) in the presence of an organic base, afforded aziridinofullerenes with various substituents on the nitrogen. The results in this Account contribute to the development of convenient methods for constructing simple and useful heterocycles. PMID:19480410

  5. Rwanda.

    Science.gov (United States)

    1985-09-01

    Rwanda's population characteristics, history, government, political situation, economy, and foreign relations were briefly discribed. Rwanda, a small African country, covers an area of 10,160 square miles and is situated between Zaire, Uganda, Burundi, and Tanzania. During the 1400s, Tutsi cattle breeders moved into the region and turned the Hutu farmers, the original occupants of the region, into serfs. The Tutsi maintained their dominant position until 1959. Rwanda was a German protectorate between 1899-1916 and a territory under the administration of Belgium following World War I. During the 1950s, the Tutsi resisted efforts by the Belgians to democratize the country, and in 1959, the Party of the Hutu Emancipation Movement (PARMEHUTU) overthrew the Tutsi monarchy. The PARMEHUTU leader, Gregoire Kayibanda was selected by the elected unicameral National Assembly to head the government following the granting of independence to Rwanda in 1962. In 1973 growing government inefficiency and corruption led to the takeover of the country by the military leader, Major General Juvenal Habyarimana, who in 1975 formed the National Revolutionary Movement for Development. Although civilian rule is being gradually restored, Habyarimana, who is now the elected president of the country, retains considerable power. In addition to the president, the country is run by a 17-member cabinet and a 70-member elected legislative body, the National Development Council. The current goverment is strongly committed to the developing the country's economy. Rwanda is a poor and overpopulated country, and its economy is based mainly on subsistence level farming. 93% of the work force is engaged in agriculture. 35% of the gross national product (GNP) is derived from agriculture, and the main agricultural products are tea, pyrethrum, and cinchona. Small-scale industries account for another 21.6% of the GNP. The government is working to increase the country's energy sources and to attract foreign

  6. Vladimir Prelog i Zavod za organsku kemiju

    Directory of Open Access Journals (Sweden)

    Jakopčić, K.

    2007-03-01

    -operation from the small but prosperous pharmaceutical company "Kaštel" in Zagreb. On behalf of the agreement, Prelog and his department obtained funds to fit up the laboratory and to start very prosperous research in the synthesis and studies of pharmaceutically interesting compounds. With his assistants, students and other collaborators, Prelog started research of cinchona bark alkaloids, preferentially oriented to the synthesis of quinine. For example, Prelog's method of double intramolecular alkylation to synthetize the quinuclidine moiety of quinine was patented by "Kaštel". With R. Seiwerth he developed the first useful synthesis of adamantane. Prelog's group started research in the field of sulphonamides and commercial success of "Streptazole" stimulated the development of the research laboratories within "Kaštel". The collaboration in the research continued in fields of other chemotherapeutics, analeptics, spasmolitics, barbiturates etc. Within the period 1935-1941, Prelog published 48 scientific papers and 8 patents. In less than seven years, his results enormously influenced the entire organic chemistry in Zagreb till nowadays. Under the confused and uncertain circumstances caused by the beginning of World War II, Prelog left Zagreb in 1941 and continued his extraordinary scientific career at the ETH in Zürich.During the war (1942-1945 the tuition and the Department were run by Dr. Rativoj Seiwerth, former collaborator and first assistant to V. Prelog. In almost unbelievable conditions, the young assistant, then assistant professor (since January 1943, R. Seiwerth fully succeeded in continuing most activities founded by Professor Prelog. After the war (1945, R. Seiwerth was forced to resign. Nevertheless, soon after R. Seiwerth continued his research work, firstly in the Institute for Industrial Research in Zagreb (1946-1952, and later in the Research Institute of "Pliva" in Zagreb. He retired in 1980.In post-war conditions (1945/46, the activity of the Technical