Search

Made available in DSpace on 2018-12-11T17:06:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-10-01 Objective To evaluate anti-Candida and anti-Cryptococcus activities of 15 non-alkaloidal compounds from Pterogyne nitens Tulasne (Leguminosae), a South American medicinal plant. Methods Compounds were submitted to antifungal assays, using microdilution method described by Clinical and Laboratory Standards Institute document, with minor modifications. Five species of Candida and two species of Cryptococcus, including clinical isolates were screened. Antifungal activity was expressed by minimum inhibitory concentration (MIC). Amphotericin B and fluconazole were used as standard antifungal drugs. Results Among tested compounds, six substances presented fungal growth inhibition (MIC < 31.2 μg/mL) [three flavone derivatives (1–3), a glycosylated flavonol derivative (5) and two phenolic acids (10 and 12)]. Sorbifolin (1), exhibited potent antifungal activity, demonstrating MIC value of 3.90 μg/mL against Candida glabrata ATCC 90030, Cryptococcus gattii 118 and fluconazole-resistant clinical isolate of Cryptococcus neoformans var. grubii. Pedalin (2) and nitensoside B (3), two glycosylated flavone derivatives, were active against Cryptococcus neoformans ATCC 90012 (MIC = 7.80 μg/mL). Conclusions Flavone derivatives from Pterogyne nitens can serve as prototypes for the design and development of innovative anti-Candida and anti-Cryptococcus hits. Laboratory of Green and Medicinal Chemistry Department of Chemistry and Environmental Sciences Institute of Biosciences Letters and Exact Sciences São Paulo State University (UNESP), São José do Rio Preto Department of Clinical Analysis School of Pharmaceutical Sciences São Paulo State University (UNESP), Araraquara Department of Organic Chemistry Institute of Chemistry São Paulo State University (UNESP), Araraquara Department of Biology and Animal Sciences Faculty of Engineering São Paulo State University (UNESP), Ilha Solteira Laboratory of Green and Medicinal Chemistry Department of Chemistry and Environmental Sciences Institute of Biosciences Letters and Exact Sciences São Paulo State University (UNESP), São José do Rio Preto Department of Clinical Analysis School of Pharmaceutical Sciences São Paulo State University (UNESP), Araraquara Department of Organic Chemistry Institute of Chemistry São Paulo State University (UNESP), Araraquara Department of Biology and Animal Sciences Faculty of Engineering São Paulo State University (UNESP), Ilha Solteira

A simple and efficient one pot method has been developed for the synthesis of some new functionalized pyrano fused flavone derivatives, alkyl 4,8-dioxo-2-phenyl-4,8-dihydropyrano[2,3-f]chromene-10-carboxylates and dialkyl 4-oxo-2-phenyl-4,8-dihydropyrano[2,3-f]chromene-8,9-dicarboxylates, from 7-hydroxy flavones and 7-hydroxy 8-formyl flavones using dialkylacetalynedicarboxylates in the presence of triphenyl phosphine. The structures of all synthesized compounds were elucidated by FT-IR, 1H and 13C NMR and Mass spectral analysis.

Our work in the area of carbon-monoxide-releasing molecules led to the synthesis and crystallization of new flavone derivatives as intermediates. Herein we report the first crystal structure of the title compound, C16H12O3, a hydroxy-substituted flavone where the 2-phenyl group has been replaced by a p-tolyl group. The introduction of the 3-hydroxy group allows the formation of intermolecular O—H...O=C hydrogen bonds, used to build centrosymmetric R 2 2(10) ring motifs in the crystal.

A highly efficient and selective Pd/C-catalyzed ligand-free cyclocarbonylation reaction for the synthesis of flavones has been developed. Various flavone derivatives were isolated in excellent yields with excellent functional group tolerances. Additionally, catalyst reuse experiments were performed successfully as well.

Synthesis of the benzannulated spiroketal core of the pinnatifinoside family of natural products, via Sonagashira cross-coupling and gold-catalysed spirocyclisation of functionalised flavone derivatives is described. These investigations lay the framework for ongoing synthetic studies towards the pinnatifinoside family, and related biologically active derivatives.

Coumarin and flavone derivatives are highly valuable molecules in drug discovery. Here, two new regioselective cross-dehydrogenation couplings of coumarins and flavones with different ethers via C(sp(3))-H functionalization processes were developed, generating new ether-substituted derivatives not previously reported. These reactions proceeded well via radical mechanisms and provided the corresponding products in good yields.

Three new flavone derivatives, paranicflavones A–C (1–3), together with three known similar compounds (4–6), were isolated from their roots and stems of Tiandeng tobacco. Their structures were elucidated by spectroscopic methods, including extensive 1H and 13C NMR techniques. Additionally, compounds 1–6 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities, and compound 2 exhibited anti-TMV activity with inhibition rate of 35.8%, which is higher than that of positive control, ningnanmycin.

The benzyl-substituted flavone compounds are rare in nature, while some of which have interesting biological activities. The total synthesis of benzyl-substituted flavone derivatives via the acidic rearrangement of benzyl groups in flavone benzyl ethers, and the complicated regioselectivity of the rearrangement were reported. The regioselectivity was proposed to be determined by the steric hindrance as well as the ease of electrophilic substitution reaction for benzyl cations at different positions of corresponding debenzylated flavone compounds.

A series of flavone derivatives conjugated with carbohydrate were synthesized from 2-(3,4-dimethoxyphenyl)-4H-chromen-4-one. The key step is its cross coupling with the carbohydrate under Sonogashira reaction.

In an attempt to create a flavone derivative able to take part in Excited State Intramolecular Double Proton Transfer (ESIDPT), we synthesized two carbonyl derivatives of 3,7-dihydroxyflavone, both containing two different proton-transfer sites as well as related carbonyl derivatives of 3-hydroxyflavone and 7-hydroxyflavone. All the examined hydroxyflavones were found to participate in the Excited State Intramolecular Proton Transfer (ESIPT). ESIPT which involves 3-hydroxyl and 4-carbonyl groups was found to have a higher barrier compared to ESIPT involving 7-hydroxyl and 6/8-carbonyl fragments. According to the data presented, 3,7-dihydroxy-2-phenyl-6-(3-phenylpropanoyl)-4H-chromen-4-one undergoes a two-stage ESIDPT with formation of an intermediate tautomer. This kind of ESIDPT leads to a tautomeric form with an abnormally low rate of radiative deactivation of the excited state, which conditions low fluorescence quantum yield. The behavior of 3,7-dihydroxy-4-oxo-2-phenyl-4H-chromene-8-carbaldehyde in the electronically excited state is similar to 3-hydroxyflavone derivatives, thus we conclude the occurrence of a single ESIPT in this compound.

Background: Prosopis cineraria (L.) Druce ('khejri') is an important tree that occurs worldwide in arid regions. It has been mentioned in the Indian Ayurvedic system of medicines as having several clinical properties. Different parts of this plant are used in India, Pakistan, Bangladesh, the United Arab Emirates, Saudi Arabia and Iran for treating various ailments such as leprosy, leucoderma, dysentery, asthma, bronchitis, piles, jaundice and muscular tremors. Since all parts of the tree are useful, it is called ‘Kalp Taru' or ‘Wonder Tree' in India. Phytochemical studies of P. cineraria have underlined the presence of various classes of phytochemicals, such as flavone derivatives (prosogerin A, B, C, D and E), alkaloids (spicigerine and prosophylline), tannins (gallic acid), steroids (stigmasterol, campesterol and sitosterol, etc.), fatty acids and amino acids, etc., that have been obtained from different parts of the plant. Methods: We undertook a comprehensive, critical and systematic literature survey on ethnomedicinal, phytochemical and pharmacological aspects of P. cineraria. Efforts were made to establish/corroborate the scientific reasons of ethnomedicinal use with the help of published modern studies. Results: Based on in-depth analysis of more than 200 studies, we were able to corroborate a large number of facts pertaining to uses of different parts of this plant for treating various maladies. Further, it yielded several new insights on phyto-pharmacological aspects of P. cineraria. Conclusion: Results of this study are useful for commercialization of the products derived from phytochemicals of P. cineraria.

Flavones have antioxidant, anti-proliferative, anti-tumor, anti-microbial, estrogenic, acetyl cholinesterase, anti-inflammatory activities and are also used in cancer, cardiovascular disease, neurodegenerative disorders, etc. Also, flavonoids are found to have an effect on several mammalian enzymes like protein kinases that regulate multiple cell signaling pathways and alterations in multiple cellular signaling pathways are frequently found in many diseases. Flavones have been an indispensable anchor for the development of new therapeutic agents. The majority of metabolic diseases are speculated to originate from oxidative stress, and it is therefore significant that recent studies have shown the positive effect of flavones on diseases related to oxidative stress. Due to the wide range of biological activities of flavones, their structure-activity relationships have generated interest among medicinal chemists. The outstanding development of flavones derivatives in diverse diseases in very short span of time proves its magnitude for medicinal chemistry research. The present review gives detail about the structural requirement of flavone derivatives for various pharmacological activities. This information may provide an opportunity to scientists of medicinal chemistry discipline to design selective, optimize as well as poly-functional flavone derivatives for the treatment of multi-factorial diseases.

The formation of methylenebis(chalcone)s has been discovered during deprotection with methoxymethyl groups from trihydroxychalcones. Studies on this methylenation reaction led to a mechanism hypothesis that was extended to other chalcones and to dihydrochalcone, acetophenone, benzophenone and flavone derivatives. This new method was applied to the rapid synthesis of natural product piperanduncin C. These original methylenebis compounds were also evaluated for their antiparasitic activity.

Prioritization of compounds using inverse docking approach is limited owing to potential drawbacks in its scoring functions. Classically, molecules ranked by best or lowest binding energies and clustering methods have been considered as probable hits. Mining probable hits from an inverse docking approach is very complicated given the closely related protein targets and the chemically similar ligand data set. To overcome this problem, we present here a computational approach using receptor-centric and ligand-centric methods to infer the reliability of the inverse docking approach and to recognize probable hits. This knowledge-driven approach takes advantage of experimentally identified inhibitors against a particular protein target of interest to delineate shape and molecular field properties and use a multilayer perceptron model to predict the biological activity of the test molecules. The approach was validated using flavone derivatives possessing inhibitory activities against principal antimalarial molecular targets of fatty acid biosynthetic pathway, FabG, FabI and FabZ, respectively. We propose that probable hits can be retrieved by comparing the rank list of docking, quantitative-structure activity relationship and multilayer perceptron models. Copyright © 2014 John Wiley & Sons, Ltd.

An efficient and practical method for effecting a tandem C-H alkenylation/C-O cyclization has been achieved via the C-H functionalization of flavone derivatives. The synthetic utility of the one-pot sequence was demonstrated by obtaining convenient access to coumarin-annelated benzopyrans. The reaction scope for the transformation was found to be fairly broad, affording good yields of a wide range of flavone- or coumarin-fused benzopyran motifs, which are privileged structures in many biologically active compounds.

Propolis, a complex resinous material collected by honeybees from buds and exudates of certain plant sources neighboring its hive, is considered to possess broad spectrum of biological activities and has historical utilization in folk medicine. Thus, it is extensively being used in health food, pharmaceutical preparations etc. The chemical consistency of propolis is highly dependent on the flora of the region from where it is collected. In this study, we investigated propolis from different geographical locations in Nepal and isolated several known compounds. As a result, we clarified the origins of propolis in Nepal.

Prosopis cineraria (L.) Druce is an important herbal plant as mentioned in ancient literature. It is used traditionally for treatment of various ailments like leprosy, dysentery, asthma, leucoderma, dyspepsia and earache etc. Various phytoconstituents like tannins (gallic acid), steroids (Stigmasterol, campesterol, sitosterol etc), Flavone derivatives (Prosogerin A, B, C, D, and E), alkaloids (Spicigerine, Prosophylline) etc has been isolated from the plant. Pharmacological activities like analgesic, antipyretic, antihyperglycemic, antioxidant, antihypercholesterolemic, antitumor, nootropic have been reported from different plant extracts. The present paper deals with review of phytoconstituents and pharmacological action of plant P. cineraria.

Background: Most of the available antimicrobial drugs have developed resistance; some of them suffer from severe toxicity, side effects. So, there is a need to discover novel compound(s) which should not only be potent, but also less toxic and cost effective. Objectives: The aim of the study is to develop new synthetic antimicrobial agents (Anti-bacterial and anti-fungal) such as 3-substituted flavone/flavanone derivatives, which should be significantly potent with low toxicity. Method: An attempt was made to synthesize a newer series of 3-methyl flavanone derivatives together with the synthesis of a series of 3-hydroxyl flavone analogues. The structures of the test compounds were elucidated and established by UV, IR, H-NMR1, C-NMR13 and mass spectrometry. The synthesized compounds were subjected for in vitro antimicrobial screening using cup plate methods, followed by the determination of zone of inhibitions. Results: Two series (each 10) of 3-methyl flavanone and 3-hydroxy flavone derivatives were synthesized. The structures of the test compounds were characterized and established by various spectroscopic methods. The synthesized compounds were screened for in vitro antibacterial and antifungal activity against different strains (3- Gram positive, 3-Gram negative and 2-fungal strains). Conclusion: Some of the 3-hydroxyl flavones derivatives (1b, 3b, 4b, and 5b) and 3-methyl flavanone derivatives (3a, 1a, 2a and 4a) were found to elicit potent antimicrobial activity. The study revealed that 3-hydroxy flavone derivatives were found to be most active against Gram negative, while 3-methyl flavanone derivatives were active against Gram positive bacteria.

Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder that is associated with the elderly. The current therapy that is used to treat AD is based mainly on the administration of acetylcholinesterase (AChE) inhibitors. Due to their low efficacy there is a considerable need for other therapeutic strategies. Considering that the malfunctions of different, but interconnected, biochemical complex pathways play an important role in the pathogenesis of this disease, a promising therapy may consist in administration of drugs that act on more than a target on biochemical scenery of AD. In this work, the synthesis and evaluation of xanthone and flavone derivatives as antioxidants with AChE inhibitory activity were accomplished. Among the obtained compounds, Mannich bases3and14showed capacity to inhibit AChE and antioxidant property, exerting dual activity. Moreover, for the most promising AChE inhibitors, docking studies on the target have been performed aiming to predict the binding mechanism. The results presented here may help to identify new xanthone and flavone derivatives as dual anti-Alzheimer agents with AChE inhibitory and antioxidant activities.

Background: Starfruit ( Averrhoa carambola ) leaves contain flavone derivatives that exhibit anti-hyperglycemic effects. This study aims to determine the effect of starfruit leaves in reducing glucose absorption in intestinal epithelial cells of mice. Methods: This study was done by performing perfusion on the small intestines of mice. The mice that were used in this study were divided into four groups. The control group was given glucose solution without infused starfruit leaves whereas, the remaining 3 groups were given 3 mmol (540 mg/dL) glucose solution with infused starfruit leaves of varying concentrations; 200, 400, and 600 mg/kg. Samples were collected at 0, 15 th , 30 th , 45 th , and 60 th minute. The sample was tested for glucose levels using spectrophotometry. Results: Test of significance showed a significant difference between the control group and the test group with p < 0.05. Conclusions: Starfruit leaves have a reduction effect towards glucose absorption in the small intestines in Wistar strains where the group using 600 mg/kg of infused starfruit leaves have the most significant effect as compared to other groups.

A novel and regioselective ammonium iodide mediated CS bond formation protocol involving flavones and sulfonyl chlorides to generate different ArS-substituted flavone derivatives in high yields was developed. Different from existing metal-free CS bond formation protocols with the use of PPh3 or I2 as the catalyst, this method provides an alternative way of constructing CS bonds through the use of NH4I as a catalyst, which makes it highly valuable for the efficient synthesis of thioether compounds.

A palladium-catalyzed oxidative arylation of chromones was examined. A regioselective 2-arylation of chromone was carried out via a double C–H activation process. The procedure provided an expedient approach for the preparation of flavone derivatives.

The chalcone derivatives, 1-(2′-hydroxyaryl)-3-(2-chloroquinolin-3-yl)-prop-2-en-1-one was transformed to corresponding flavone derivatives by iodine impregnated neutral alumina under microwave irradiation. The synthesized flavone derivatives were structurally confirmed by elemental analysis, UV, IR and1H-NMR spectral data, and the notable yield obtained was compared with previously reported method.

A new series of flavonyl compounds (1–10) was prepared and tested for their in-sulinotropic activities in INS-1 cells. Compounds 2, 5 and 6 (at higher concentrations) and compounds 3 and 7–10 were able to increase insulin release in the presence of 5.6 mmol/l glucose at both concentrations used (1 and 10 μg/ml).

A catalytic amount of DMAP promoted cyclization of o-alkynoylphenols via a 6-endo cyclization mode leading to flavone derivatives in high yields without forming 5-exo cyclized aurone derivatives. Utilizing this method, methoxy substituted flavone and alkyl substituted γ-benzopyranone derivatives were synthesized.

The synthesis of some natural and synthetic biflavonoids was performed in good overall yields starting from readily available materials via high yielding aldol and Ullmann condensations. Some of these compounds, especially bichalcones, display an interesting activity against fungi, higher than that of the corresponding monomers.

Two new acylated flavone C-glycosides, 6''-O-(2'''-methylbutyryl)isoswertisin (1) and 6''-O-(2'''-methylbutyryl)isoswertiajaponin (2), together with four known acylated flavone C-glycosides, were isolated for the first time from the whole plants of Hemistepta lyrata (Compositae). Their structures were elucidated on the basis of chemical and spectroscopic methods including HR-ESI-MS, ESI-MS, UV, IR, and 1D and 2D NMR spectral techniques.

Two new glycosides, 1,6-di-O-syringoyl-β-d-glucopyranose (1) and quercetin 3-O-[(3-O-syringoyl-α-l-rhamnopyranosyl)-(1 → 6)-β-d-glucopyranoside] (2), along with seven known compounds were isolated from the MeOH extract of Leonurus japonicus. The structures of these compounds were elucidated by spectral analysis.

A synthetic precursor cis-[RuIICl2(dmso)4] is complexed separately with 3-(4-benzyloxyphenyl)-1-(2-hydroxylphenyl)-prop-2-en-1-one (L1H) and 2-(4-benzyloxyphenyl)-3hydroxy-chromen-4-one (L2H). The resulting complexes are assigned the composition fac-[RuCl(S-dmso)3(L1)] 1 and fac-[RuCl(S-dmso)3(L2)] 2 using elemental analyses, FAB mass data and spectroscopic (IR, 1H NMR, UV–Vis, emission) spectral properties. The X-ray diffraction analysis shows that complexes self-associate through non-covalent interactions and provide 1D and 2D supramolecular structures. These complexes are assayed for their cytotoxicity studies on Dalton Lymphoma cell lines.

In this paper, a simple and novel synthesis of baicalein is described. This transformation features the novel synthesis of helilandin B and a different way to demethylate. The overall yield of 59% is acceptable.

An expeditious synthesis of three polyoxygenated flavones mosloflavone, negletein and baicalein. starting from crysin, an easily available flavone, by a bromination/methoxylation procedure is reported The convergent synthesis exploits a base induced Wesley-Moser type rearrangement (C) 2009 Elsevier Ltd All rights reserved

We establish useful models that relate experimentally measured biological activities of compounds to their molecular structure. The pED50 feeding inhibition on Spodoptera litura species exhibited by aurones, chromones, 3-coumarones and flavones is analyzed in this work through the hypothesis encompassed in the Quantitative Structure?Activity Relationships (QSAR) Theory. This constitutes a first necessary computationally based step during the design of more bio-friendly repellents that could lead to insights for improving the insecticidal activities of the investigated compounds.After optimizing the molecular structure of each furane and pyrane benzoderivative with the semiempirical molecular orbitals method PM3, more than a thousand of constitutional, topological, geometrical and electronic descriptors are calculated and multiparametric linear regression models are established on the antifeedant potencies. The feature selection method employed in this study is the Replacement Method, which has proven to be successful in previous analyzes. We establish the QSAR both for the complete molecular set of compounds and also for each chemical class, so that acceptably describing the variation of the inhibitory activities from the knowledge of their structure and thus achieving useful predictive results. The main interest of developing trustful QSAR models is that these enable the prediction of compounds having no experimentally measured activities for any reason. Therefore, the structure?activity relationships are further employed for investigating the antifeedant activity on previously synthesized 2-,7-substituted benzopyranes, which do not pose any measured values on the biological expression. One of them, 2-(α-naphtyl)-4H-1-benzopyran-4-one, results in a promising structure to be experimentally analyzed as it has predicted pED50=1.162. Fil: Duchowicz, Pablo Román. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Goodarzi, Mohammad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Ocsachoque, Marco Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; Argentina Fil: Romanelli, Gustavo Pablo. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; Argentina Fil: Ortiz, Erlinda del Valle. Universidad Nacional de Catamarca. Facultad de Tecnologia y Ciencias Aplicadas; Argentina. Comision Nacional de Investigacion Cientifica y Tecnologica; Chile Fil: Autino, Juan C.. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; Argentina Fil: Bennardi, Daniel Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; Argentina Fil: Ruiz, Diego Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; Argentina Fil: Castro, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina

High-performance liquid chromatography with diode-array detection has been used to evaluate the quality of Erxian decoction (EXD), a Chinese medicine prescription, by use of a combination of fingerprinting and simultaneous quantification of six marker compounds. The standard chromatographic fingerprint containing forty common peaks was constructed from seven batches of the EXD samples to evaluate batch-to-batch consistency. In addition, six representative bioactive markers were simultaneously quantified with good linearity, precision, repeatability, and accuracy. The fingerprint accompanied by quantification of the marker compounds can be used to evaluate the quality of EXD.

A novel C-glycosylflavone with unusual alpha-orientation at the anomeric center of d-glucose was isolated from the leaves of Diospyros kaki. Its structure was determined as 8-C-[alpha-l-rhamnopyranosyl-(1 --4)]-alpha-d-glucopyranosylapigenin by chemical methods and spectral experiments.

The reliability of evaluation of compound purity depends on the analytical method selected. A suitable analytical method, including the modes of separation and detection, can provide reliable information about compound purity. Effective separation is the key to achieving precise results. In this work we developed a novel method, based on an orthogonal system, RP-LC-hydrophilic interaction liquid chromatography, for evaluating the purity of compounds isolated by preparative reversed-phase liquid chromatography. Because of its good orthogonality, good separation and more accurate assessment of compound purity could be achieved.

A new acylated flavone glycoside, echioidinin 2'-O-beta-D-(2''-O-acetyl)glucopyranoside (1) along with the three known flavonoids, 5,6,7,8,5'-pentamethoxy-3',4'-methylenedioxyflavone (2), 5,2',6'-trihydroxy-7-methoxyflavone (3), and kaempferol 7,4'-dimethyl ether 3-O-beta-D-glucopyranoside (4), were isolated from the roots of Colebrookea oppositifolia. The structure of compound 1 was elucidated by extensive spectral and chemical studies.

Two new steroidal saponins and two known flavonoid glycosides were isolated from the fruits of Tribulus terrestris. Their structures were assigned by spectroscopic analysis and chemical reaction as 26-O-beta-D-glucopyranosyl-(25R)-5 alpha-furostan-12-one-3beta,22 alpha,26-triol-3-O-beta-D-glucopyranosyl (1 --2)-beta-D-glucopyranosyl(1 --4)-beta-D-galactopyranoside (1), 26-O-beta-D-glucopyranosyl-(25S)-5 alpha-furostan-22-methoxy-2 alpha,3beta,26-triol-3-O-beta-D-glucopyranosyl(1 --2)-beta-D-glucopyranosyl(1 --4)-beta-D-galactopyranoside (2), kaempferol-3-gentiobioside (3), and isorhamnetin-3-gentiobioside (4).

Quantitative structure–activity relationship (QSAR) has been established for 32 oxime- and methyloxime-containing flavone and isoflavone derivatives having antiproliferative activity. Multiple linear regressions were used to generate the relationship between biological activity and calculated descriptors. Model with good statistical qualities was developed using the software VLIFE MDS 2.0. Validation of the model was done by cross-validation, randomization, and external test set prediction. On the basis of the QSAR model, we designed a new series of compounds and calculated the activity and found that the compounds were more potent than the existing compounds. QSAR studies of flavone and isoflavone derivatives. The negative coefficient of SdOi indicated that its increase is detrimental to antiproliferative activity. The positive coefficient of QMDMg showed that the magnitude of dipole is responsible for the activity.

A rapid LC-photodiode array method for the separation and identification of secondary plant metabolites especially phenolic compounds belonging to different types in a run (35 min) has been developed. The method has been optimized and validated using the selectivity, precision, recovery and robustness parameters with an aim for standardization of herbal drugs. Almost all the compounds have linearity with an R 2 more than 98% and an RSD of less than 5% (in terms of variation of retention time). Inter-day and intra-day variability was also found to be less than 5%. The method thus developed has been successfully applied in identification and quantification of phenolic compounds present in polyherbal ayurvedic formulation (Ashokarishta). The results indicate that the method developed is rapid, accurate and robust for the analysis of different classes of phenolic compounds and can be successfully applied in the quality control and standardization of herbal drugs as well as polyherbal formulations.

Two new flavonoids, compounds 1 and 2, together with seven known flavonoids, were isolated from Galium verum L. Their structures were elucidated as diosmetin 7-O-alpha-l-rhamnopyranosyl-(1-2)-[beta-d-xylopyranosyl-(1-6)]-beta-d-glucopyranoside (1) and 3,5,7,3',4',3'',5'',7'',3''',4'''-decahydroxyl-[8-CH(2)-8'']-biflavone (2) by chemical methods and spectroscopic analyses. Compounds 3 and 4 were isolated from the genus Galium for the first time.

A high performance liquid chromatographic method has been performed for the simultaneous identification and quantification of ten bioactive components in three botanical materials of Rhodiola genus (R. crenulata, R. sachliensis and R. dumulos). Eight samples of Rhodiola genus prepared from three different botanical materials were investigated by the proposed method, and the variance was revealed by the calculated results of these contents and similarity values for ten main flavonoids. The proposed method is simple, effective, and suitable for the evaluation of this traditional Chinese medicine.

A novel and highly regioselective ammonium iodide-induced nonradical sulfenylation method for the construction of a C–S bond was developed via C–H functionalization. With DMSO or R1SO2NHNH2 as a sulfenylating agent, MeS- and R1S-substituted flavone derivatives were obtained in good yields. This method enriches current C–S bond formation chemistry, making it a highly valuable and practical method in pharmaceutical industry.

The synthesis and biological activity of a new series of 2-{3-[substituted benzylamino-methyl)-phenyl]-4H-benzopyrane-4-one (IVa-e) and N-substituted benzyl-N-[3-(4-oxo-4H-benzopyrane-2-yl)benzyl]-3-phenyl-acrylamide (Va-e) derivatives are reported. The synthesized compounds were tested in vitro for antifungal and antibacterial activities. Compound IVa showed the best antifungal activity compared with miconazole (CAS 22916-47-8). Compound IVc indicated the best antibacterial activity compared with the control drug ampicillin (CAS 69-53-4).

The and chemical shifts of eleven flavone derivatives were completely determined by basic 1D and 2D NMR experiments. Nineteen flavone derivatives including the above eleven derivatives were examined for anti-oxidative effects using the 1,1-diphenyl-2-picryl-hydrazyl assay and Caenorhabditis elegans. In order to understand the relationships between the structures of flavone derivatives and their anti-oxidative activities, a Comparative Molecular Field Analysis was performed. 먿♸娈

A novel flavonoid, [2-(3,4-dihydroxy-phenyl)-3,5,7-trihydroxy-4-oxo-4H-chromen-8-yl]-[8-hydroxy-7-(E-4-hydroxy-3-methyl-but-2-enyl)-2,2-dimethyl-chroman-5-yl]-acetic acid methyl ester (10), trivially named sabian, along with 11 known compounds, have been isolated from the stems and leaves of Sabiayunnanensis. Their structures were established on the basis of spectral analysis.