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Showing papers on "Flavanone published in 2004"


Journal ArticleDOI
TL;DR: Naturally occurring polyphenolics tested followed the expected general trends of phenolic acids and flavonoids, and synthetic antioxidant food additives conventionally used in the food industry were less effective antioxidants than ascorbic acid.
Abstract: Antioxidant capacity for a wide range of natural or synthetic polyphenolics was comprehensively evaluated by vitamin C equivalent antioxidant capacity (VCEAC) assay using free blue/green ABTS radicals. The polyphenolics tested are grouped into the following categories: vitamins (β-carotene, α -tocopherol, vitamin A, and vitamin C), phenolic acids (benzoic acid, phenylacetic acid, cinnamic acid, and their derivatives), flavonoids (anthocyanidin, flavanol, chalcone, flavanone, flavone, flavonol, isoflavone, and their derivatives), synthetic food additives (BHA, BHT, TBHQ, and PG), and other miscellaneous polyphenolics (ellagic acid, sesamol, eugenol, thymol, etc.). A positive linear relationship between VCEAC and the number of free OH groups around the flavonoid framework was found, whereas, for phenolic acids, the linear relationship was not as good as with the flavonoid aglycones. Groups of chemicals having comparable structures generally showed similar trends. Polyphenolics commonly showed a higher VCEAC...

381 citations


Journal Article
TL;DR: Spectrometric analyses of flavonoids in twenty propolis samples, collected from ten different geographic localities in northern Croatia using two complementary methods, are reported, showing the high variability of flavanone concentration will affect the biological activity of propolis preparations.
Abstract: Spectrometric analyses of flavonoids in twenty propolis samples collected from ten different geographic localities in northern Croatia using two complementary methods, are reported. Flavones and flavonols were determined using aluminum chloride and expressed as quercetine equivalent while flavanones were determined using 2,4-dinitrophenylhydrazine and expressed as naringenin. Contents of flavones and flavonols were similar for most samples and ranged from 2 to 2.3%, except for one sample with a concentration of 1.3% and one sample in which it was not possible to detect flavones and flavonols. The content of flavanones in propolis samples is very variable. 55% of samples contain flavanons between 15 and 24% and 45% of samples between 4 and 14%. Total levels of flavonoids in raw propolis samples ranged between 5 and 26%; for the majority of samples (75%), the total level of flavonoids ranged between 15 and 25.9%. The high variability of flavanone concentration will affect biological activity of propolis preparations.

245 citations


Journal ArticleDOI
TL;DR: Results imply that oxygen exchange can occur at a stage subsequent to initial oxidation of the C-ring, probably via an enzyme-bound C-3 ketone/3,3-gem-diol intermediate, and supports the intermediacy of a reactive oxidizing species.

189 citations


Journal ArticleDOI
TL;DR: The cloning and coexpression in Escherichia coli of phenylalanine ammonia lyase, cinnamate‐4‐hydroxylase, 4‐coumarate:CoA ligase, and chalcone synthase from the model plant Arabidopsis thaliana are reported, with high‐level production of the flavanone naringenin observed for the first time.
Abstract: Flavonoids are important plant-specific secondary metabolites synthesized from 4-coumaroyl coenzyme A (CoA), derived from the general phenylpropanoid pathway, and three malonyl-CoAs. The synthesis involves a plant type III polyketide synthase, chalcone synthase. We report the cloning and coexpression in Escherichia coli of phenylalanine ammonia lyase, cinnamate-4-hydroxylase, 4-coumarate:CoA ligase, and chalcone synthase from the model plant Arabidopsis thaliana. Simultaneous expression of all four genes resulted in a blockage after the first enzymatic step caused by the presence of nonfunctional cinnamate-4-hydroxylase. To overcome this problem we fed exogenous 4-coumaric acid to induced cultures. We observed high-level production of the flavanone naringenin as a result. We were also able to produce phloretin by feeding cultures with 3-(4-hydroxyphenyl)propionic acid. Feeding with ferulic or caffeic acid did not yield the corresponding flavanones. We have also cloned and partially characterized a new tyrosine ammonia lyase from Rhodobacter sphaeroides. Tyrosine ammonia lyase was substituted for phenylalanine ammonia lyase and cinnamate-4-hydroxylase in our E. coli clones and three different growth media were tested. After 48 h induction, high-level production (20.8 mg L(-1)) of naringenin in metabolically engineered E. coli was observed for the first time.

171 citations


Journal ArticleDOI
TL;DR: The results show that the immature fruits from cultivars Lisbon and Fino-49 and the leaves of cultivar Eureka are the most interesting for obtaining the flavone diosmin and the flavanone eriocitrin.

164 citations


Journal ArticleDOI
TL;DR: Assay guided fractionation led to the isolation of two chalcones, one flavanone and a new caffeoyl ester derivative as the compounds responsible for the antifungal activity of Zuccagnia punctata.
Abstract: The crude methanolic extract of Zuccagnia punctata was active toward the fungal pathogens of soybean Phomopsis longicolla and Colletotrichum truncatum. Assay guided fractionation led to the isolation of two chalcones, one flavanone and a new caffeoyl ester derivative as the compounds responsible for the antifungal activity. Another new caffeoyl ester derivative was isolated from the antifungal chloroform extract but proved to be inactive against the soybean infecting fungi up to 50 Ig/mL

121 citations


Journal ArticleDOI
TL;DR: Results of the MTT assay indicate that 2'-OH flavanone showed the most potent cytotoxic effect on these three cells, and cell death induced by 2'- OH flavan one was via the occurrence of DNA ladders, apoptotic bodies, and hypodiploid cells, all characteristics of apoptosis.

117 citations


Patent
01 Jul 2004
TL;DR: In this article, methods and compositions for modulating the activity of sirtuin deacetylase protein family members are presented, including p53 activity; apoptosis; lifespan and sensitivity to stress of cells and organisms.
Abstract: Provided herein are methods and compositions for modulating the activity of sirtuin deacetylase protein family members; p53 activity; apoptosis; lifespan and sensitivity to stress of cells and organisms. Exemplary methods comprise contacting a cell with an activating compound, such as a flavone, stilbene, flavanone, isoflavone, catechin, chalcone, tannin or anthocyanidin; or an inhibitory compound, such as a sphingolipid, e.g., sphingosine.

106 citations


Journal ArticleDOI
TL;DR: Leaves of Chrysanthemum morifolium cv.
Abstract: Leaves of Chrysanthemum morifolium cv. Ramat were extracted sequentially with hexane, ethyl acetate, and methanol. The methanol fraction, when incorporated into artificial diet was found to reduce the growth of cabbage looper (Trichoplusia ni Hubner) larvae at concentrations between 500 and 5000 ppm of diet. Fractionation of the methanol extract on a Sephadex column yielded five fractions, three of which reduced the weight of larvae relative to the control. One fraction was analyzed using high performance liquid chromatography (HPLC) and found to contain three main constituents. These compounds were purified using a combination of gel permeation chromatography on Sephadex LH20 and HPLC, and analyzed by 1H and 13CNMR as well as undergoing chemical and physical analyses. The compounds were identified as: 1, chlorogenic acid (5-O-caffeoylquinic acid); 2, 3,5-O-dicaffeoylquinic acid; and 3, 3', 4',5-trihydroxyflavanone7-O-glucuronide (eriodictyol7-O-glucuronide). At concentrations between 100 to 1000 ppm these compounds reduced both growth and photosynthesis of Lemna gibba L. with the order of efficacy being: flavanone > chlorogenic acid > 3,5-O-dicaffeoylquinic acid. Furthermore, when incorporated separately into artificial diet these compounds, at 10 to 1000 ppm, enhanced or reduced growth of the cabbage looper (Trichoplusia ni) and gypsy moth (Lymantria dispar L.).

103 citations


Journal ArticleDOI
TL;DR: From the ethyl acetate extract of the stem bark of Erythrina abyssinica, a new chalcone, 2',3,4,4'-tetrahydroxy-5-prenylchalcone (trivial name 5- prenylbutein) and a new flavanone along with known flavonoids have been isolated as the anti-plasmodial principles.

103 citations


Journal ArticleDOI
TL;DR: Xanthohumol (1), isolated from hop, was fed to rats in a dose of 1000 mg kg(-1) body weight and analysed for metabolites, which consisted of unchanged 1.5% flavonoid-compounds and 20 metabolites had a modified chalcone structure and two metabolites were flavanone derivatives.

Journal ArticleDOI
TL;DR: This work investigated the in vitro metabolism of 8-prenylnaringenin by human liver microsomes and identified a total of 12 metabolites, and biotransformation occurred on the prenyl group and the flavanone skeleton.
Abstract: The female flowers of hops are used throughout the world as a flavoring agent for beer. Recently, there has been increasing interest in the potential estrogenic properties of hop extracts. Among the possible estrogenic compounds in hops, 8-prenylnaringenin is perhaps most significant due to its high in vitro potency exceeding that of other known phytoestrogens. Since data regarding the pharmacokinetic properties of this compound are lacking, we investigated the in vitro metabolism of 8-prenylnaringenin by human liver microsomes. A total of 12 metabolites were identified, and biotransformation occurred on the prenyl group and the flavanone skeleton. The major site of oxidation was on the terminal methyl groups, and of the two possible isomers, the transisomer was more abundant. The double bond on the prenyl group was also oxidized to an epoxide that was opened by intramolecular reaction with the neighboring hydroxyl group. On the flavanone skeleton, the major site of oxidation was at 3'position on the B ring. Other metabolites included oxidation at carbon-3 as well as desaturation of the C ring to produce 8-prenylapigenin. An unusual hydroxy quinone product formed by ipso hydroxylation of the B ring of 8-prenylnaringenin was also detected. This product was probably an intermediate for the B ring cleavage product, 8-prenylchromone.

Journal ArticleDOI
TL;DR: The distribution of flavonoids observed in R. officinalis suggests a functional and structural relationship between phytoregulators and flavonoid, where Flavonoids would be "protectors" of the activity of phytOREgulators.
Abstract: The distribution of seven flavonoids, eriocitrin, luteolin 3'-O-beta-d-glucuronide, hesperidin, diosmin, isoscutellarein 7-O-glucoside, hispidulin 7-O-glucoside, and genkwanin, has been studied in Rosmarinus officinalis leaves, flowers, stems, and roots during plant growth. The maximum level reached by luteolin 3'-O-beta-d-glucuronide in leaves during June-August suggests the existence of a delay between the activation of the enzymes involved in the flavanone and flavone biosynthesis. The presence of hesperidin and diosmin in the vascular system is significant, and hesperidin shows even higher levels than the phenolic diterpenes and rosmarinic acid. The distribution of flavonoids observed in R. officinalis suggests a functional and structural relationship between phytoregulators and flavonoids, where flavonoids would be "protectors" of the activity of phytoregulators. A hypothesis for the general pathway of biosynthesis of these compounds in plants of the family Labiatae is proposed.

Journal ArticleDOI
TL;DR: The in vitro study revealed that these compounds acted as antifungal agents, the most active being the aglycons (naringenin and hesperetin), followed by the polymethoxyflavones and flavanone glycosides.
Abstract: Phytophthora citrophthora causes serious losses in Citrus fruits through brown rot lesion. The effect of infection with P. citrophthora on Citrus sinensis (cv. Valencia Late) fruits was studied, with particular reference to the levels of the flavanones hesperidin and isonaringin and the polymethoxyflavones sinensetin, nobiletin, tangeretin, and heptamethoxyflavone, because flavonoids are most probably involved as natural defense or resistance mechanisms in this genus. Changes in the levels of these flavonoids were detected after infection. The hesperidin and isonaringin contents fell by 13 and 67%, respectively, whereas the contents of their corresponding aglycons, hesperetin and naringenin, increased, suggesting the hydrolyzing effect of this fungus on the glycosylated flavanones. The heptamethoxyflavone, nobiletin, sinensetin, and tangeretin levels increased by 48, 28, 26, and 24%, respectively. The in vitro study revealed that these compounds acted as antifungal agents, the most active being the aglycons (naringenin and hesperetin), followed by the polymethoxyflavones and flavanone glycosides. The participation of these flavonoids in the defense mechanism of this Citrus species is discussed.

Journal ArticleDOI
TL;DR: Inhibition of the superoxide anion reduction of nitroblue tetrazolium showed that a significant amount of the total antioxidant activity in orange peel molasses was attributable to minor-occurring flavones, including polymethoxylated flavones and flavanone-O-trisaccharides.
Abstract: Orange peel molasses, a byproduct of juice production, contains high concentrations of phenols, including numerous flavanone and flavone glycosides, polymethoxylated flavones, hydroxycinnamates, and other miscellaneous phenolic glycosides and amines. Extensive fractionation of these phenols was achieved by adsorption, ion exchange, and size exclusion chromatography. Size exclusion chromatography effectively separated the different classes of flavonoids in ultrafiltered molasses, including the polymethoxylated flavones, flavanone-O-trisaccharides, flavanone- and flavone-O-disaccharides, and, finally, flavone-C-glycosides. Mass spectral analysis of the early-eluting flavonoid fractions off the size exclusion column revealed a broad collection of minor-occurring flavone glycosides, which included, in part, glycosides of limocitrin, limocitrol, and chrysoeriol. Most hydroxycinnamates in the molasses were recovered by ion exchange chromatography, which also facilitated the recovery of fractions containing many other miscellaneous phenols. Total antioxidant levels and total phenolic contents were measured for the separate categories of phenols in the molasses. Inhibition of the superoxide anion reduction of nitroblue tetrazolium showed that a significant amount of the total antioxidant activity in orange peel molasses was attributable to minor-occurring flavones. The miscellaneous phenolic-containing fractions, in which a large portion of the total phenolic content in molasses occurred, also constituted a major portion of the total antioxidants in ultrafiltered molasses.

Journal ArticleDOI
TL;DR: Thirty-seven flavonoid compounds were investigated for their effect on feeding choice with bertha armyworm and flavone reduced both larval weight as well as larval and pupal development time in a no-choice bioassay.
Abstract: Thirty-seven flavonoid compounds (9 flavones, 18 flavonols, 8 flavanones, and 2 flavanonols) were investigated for their effect on feeding choice with bertha armyworm (Mamestra configurata Walker; BAW). Feeding choice was dependent upon subtle differences in biochemical structure. Unsubstituted flavone and flavanone were the strongest feeding deterrents in the choice bioassay, while 7,4′-dihydroxyflavone and dihydroquercetin stimulated BAW to feed. The constitutive flavonoids of Brassica napus, isorhamnetin-3-sophoroside-7-glucoside and kaempferol-3,7-diglucoside, were effective deterrents when supplemented at concentrations higher than endogenous levels. In a no-choice bioassay, flavone reduced both larval weight as well as larval and pupal development time.

Journal ArticleDOI
TL;DR: First total synthesis of flavocommelin, a component of the blue supramolecular pigment, commelinin, from Commelina communis, by direct 6-C-glycosylation of the flavan 4 using perbenzylglucosyl fluoride 8 in the presence of MS 5 angstroms in CH2Cl2 and a catalytic amount of BF3 x Et2O.
Abstract: We succeeded in a first total synthesis of flavocommelin (1), a component of the blue supramolecular pigment, commelinin (2), from Commelina communis, by direct 6-C-glycosylation of the flavan 4 using perbenzylglucosyl fluoride 8 in the presence of MS 5 angstroms in CH2Cl2 and a catalytic amount of BF3 x Et2O. After 6-C-glycosylation of 4, oxidation with CAN to flavanone 18 and subsequent 4'-O-glycosylation, promoted with a combination of BF3 x Et2O and DTBMP, afforded diglucosylflavanone 20. DDQ oxidation of 20 and deprotection successively gave 1.

Journal ArticleDOI
TL;DR: The full-length cDNA clones for 18 glucosyltransferase (GT) genes were isolated from petal tissue of carnation (Dianthus caryophyllus) bearing various flower colors and three of the 18 were characterized as 3-GT possessing different substrate specificities for flavonoids and anthocyanidin.
Abstract: Yellow petals of carnations contain chalcone 2′-O-glucoside. The glucosylation occurs after the p-coumaroyl CoA and malonyl-CoA condensation reaction by chalcone synthase (CHS), but the enzyme(s) transferring glucose from UDP-glucose to the 2′-OH position of chalcone has not been identified. The full-length cDNA clones for 18 glucosyltransferase (GT) genes were isolated from petal tissue of carnation (Dianthus caryophyllus) bearing various flower colors. The 18 GTs encoded in the cDNAs were enzymatically characterized in an E. coli expression system using chalcone, flavanone, flavone, flavonol and anthocyanidin as substrates. Three of the 18 were characterized as 3-GT possessing different substrate specificities for flavonoids and anthocyanidin and another two GTs catalyzed the transfer of glucose to the 2′-hydroxyl group of chalcone. In addition, these two enzymes glucosylated flavonol (3-OH and 7-OH), flavanone (7-OH), flavone (7-OH) and anthocyanidin (3-OH and 7-OH).

Journal ArticleDOI
TL;DR: Kurarinone, a lavandulyl flavanone, was isolated from a polyphenolic extract of the roots of Sophora flavescens using fractionation guided by estrogenic activity, which was determined by recombinant yeast and Ishikawa Var-I bioassays.
Abstract: Kurarinone, a lavandulyl flavanone, was isolated from a polyphenolic extract of the roots of Sophora flavescens using fractionation guided by estrogenic activity, which was determined by recombinant yeast and Ishikawa Var-I bioassays. Kurarinone showed weak estrogenic activity both in the yeast screen and in the Ishikawa Var-I assay with EC(50) values of 4.6 and 1.66 microM, respectively. Furthermore, kurarinone was found to have potent cytotoxic activity (IC(50) value = 22.2 microM) against human MCF-7/6 breast cancer cells in the sulforhodamine-B assay.

Journal ArticleDOI
TL;DR: The results showed that hesperidin was present in orange juices almost exclusively as the 2S isomer, whereas narirutin had mainly the 2R configuration, whereas the opposite was true for narirUTin in grapefruit juices.
Abstract: The major flavanone-7-O-glycoside constituents in citrus fruit juices (naringin, hesperidin, neohesperidin, narirutin, and eriocitrin) were separated as diastereomers by multidimensional liquid chromatography. The method consisted of coupling two HPLC columns: a reversed-phase (RP18) column was used for the separation of flavanone glycosides, which were, then, individually switched into a carboxymethylated β-cyclodextrin (β-CD)-based column and resolved as the corresponding stereoisomers. The method was used for the full analysis of flavanone glycosides in fresh hand-squeezed and commercial fruit juices by combining the quantitative estimation with the diastereomeric analysis. Quantitative data were in general consistent with previously reported data in this field. CC-LC isomer analysis was carried out by coupling the β-CD column with a mass spectrometer operated with negative ion electrospray ionization (ESI-MS). The results showed that hesperidin was present in orange juices almost exclusively as the 2...

Journal ArticleDOI
TL;DR: A flavanone and a Flavanone glycoside, together with vomifoliol, have been isolated for the first time from the aerial parts of the plant Echiochilon fruticosum and identified.
Abstract: A flavanone and a flavanone glycoside, together with vomifoliol, have been isolated for the first time from the aerial parts of the plant Echiochilon fruticosum and identified. Their structures were established on the basis of spectroscopic measurements, mainly 2D NMR using COSY, HMQC and HMBC experiments.

Journal ArticleDOI
TL;DR: Flavanone with hydroxylation at C4' and C6 had a significant cytotoxic effect in human leukemia HL-60 cells accompanied by the occurrence of DNA ladders, apoptotic bodies, and hypodiploid cells, characteristics of apoptosis, which suggests that hydroxolation is important to the apoptosis-inducing activities of flavanone through ROS production.

Journal ArticleDOI
TL;DR: Four lavandulyl flavanones, which are isolated from the roots of Sophora flavescens, have been tested for in vitro antimalarial activity against Plasmodium falciparum and it is suggested that the position of methoxyl groups in flavanone skeleton plays an important role on antimalaria activity.
Abstract: Four lavandulyl flavanones, (2S)-2′-methoxykurarinone (1), sophoraflavanone G (2), leachianone A (3), and (−)-kurarinone (4), which are isolated from the roots of Sophora flavescens have been tested for in vitro antimalarial activity against Plasmodium falciparum. Compounds 1—3 showed moderate antimalarial activities with EC50 values of 2.4×10−6, 2.6×10−6, and 2.1×10−6 M, respectively. These compounds did not show selective toxicity against P. falciparum in the toxicity test on mouse mammalian tumor cells, however, it is suggested that the position of methoxyl groups in flavanone skeleton plays an important role on antimalarial activity.

Journal ArticleDOI
TL;DR: The human fecal anaerobe Eubacterium ramulus is capable of degrading various flavonoids, including the flavone naringenin, and the first report on a bacterial chalcone isomerase is reported, which catalyzed the isomerization of naringein chal cone, isoliquiritigenin and butein, three chalcones that differ in their hydroxylation pattern.
Abstract: The human fecal anaerobe Eubacterium ramulus is capable of degrading various flavonoids, including the flavone naringenin. The first step in the proposed degradation pathway is the isomerization of naringenin to the corresponding chalcone. Cell-free extracts of E. ramulus displayed chalcone isomerase activity. The enzyme from E. ramulus was purified to homogeneity. Its apparent molecular mass was estimated to be 136 and 129 kDa according to gel filtration and native polyacrylamide gel electrophoresis, respectively. Chalcone isomerase is composed of one type of subunit of 30 kDa. The purified enzyme catalyzed the isomerization of naringenin chalcone, isoliquiritigenin, and butein, three chalcones that differ in their hydroxylation pattern. N-bromosuccinimide, but also naringenin and phloretin, inhibited the purified enzyme considerably. This is the first report on a bacterial chalcone isomerase. The physiological function of the purified enzyme is unclear, but an involvement in the conversion of the flavanone naringenin to the chalcone is proposed.

Journal ArticleDOI
TL;DR: Three flavanones and two isoflavones were isolated from the Spatholobus suberectus (Leguminosae) and all of these compounds are reported for the first time from this plant through the present study.
Abstract: Two pterocarpans [(6aR,11aR)-maackiain, (6aR,11aR)-medicarpin], one flavanone [(2S)-7-hydroxy-6-methoxy-flavanone], one isoflavan (sativan) and two isoflavones (pseudobaptigenin, genistein) were isolated from the Spatholobus suberectus (Leguminosae) Their chemical structures were determined by comparison of their spectroscopic parameters of CD, EIMS, 1D-NMR and 2D-NMR with those reported in the literatures All of these compounds are reported for the first time from this plant through the present study

Patent
01 Jul 2004
TL;DR: In this paper, methods and compositions for modulating the activity of sirtuin deacetylase protein family members are presented, including p53 activity; apoptosis; lifespan and sensitivity to stress of cells and organisms.
Abstract: Provided herein are methods and compositions for modulating the activity of sirtuin deacetylase protein family members; p53 activity; apoptosis; lifespan and sensitivity to stress of cells and organisms. Exemplary methods comprise contacting a cell with an activating compound, such as a flavone, stilbene, flavanone, isoflavone, catechin, chalcone, tannin or anthocyanidin; or an inhibitory compound, such as a sphingolipid, e.g., sphingosine.

Journal ArticleDOI
TL;DR: In this article, the reaction of 2′-hydroxyacetophenone with benzaldehyde was studied over H-ZSM-5, Mg-Zsm-5 and Ba-Z SM-5 catalysts at 140°C.
Abstract: The reaction of 2′-hydroxyacetophenone with benzaldehyde was studied over H-ZSM-5, Mg-ZSM-5 and Ba-ZSM-5 catalysts at 140 °C. The products were 2′-hydroxychalcone and flavanone. The conversion of 2′-hydroxyacetophenone increased with time and attained a maximum of 40–50% conversion over all the catalysts. Though the yield of chalcone and flavanone increased with increase in time, the yield of flavanone was less than 2′-hydroxychalcone over all the catalysts. The order of activity of the catalysts was Mg-ZSM-5 > Ba-ZSM-5 > H-ZSM-5. The influence of temperature in the range of 100–160 °C on conversion and products yield was studied over Mg-ZSM-5. The increase in conversion was small between 100 and 120 °C, but above 120 °C there was a marked increase in conversion. The optimal catalyst loading was found to be 0.75 g for 10 mmol reactants. Study of influence of time on Mg-ZSM-5 at 160 °C revealed a rapid increase in conversion and products yield up to 3 h and a steady state afterwards. The role of solvent in this reaction was studied with DMSO, nitrobenzene and a mixture of DMSO and nitrobenzene. High conversion was observed with DMSO.

Journal ArticleDOI
TL;DR: It was found that among flavonoids tested, unhydroxylated flavone compound and flavanone hesperidin were the most active and gallic acid compound with para-methoxy group was the most effective among phenolic acids tested.
Abstract: The relationship between the structure of 14 phenolic compounds and their molluscicidal activity against the molluscan intermediate host of urinary schistosomiasis, Bulinus truncatus, is discussed. It was found that among flavonoids tested, unhydroxylated flavone compound and flavanone hesperidin were the most active (LC50 = 5.47 and 8.91 ppm, respectively), whereas gallic acid compound with para-methoxy group was the most effective among phenolic acids tested (LC50 = 3.60 ppm). These results are encouraging and prove other biological application of these compounds.

Journal ArticleDOI
TL;DR: The reported chemical modification of interesting lead substances (like the strongly estrogenic 8-PN) presents a promising approach to modulate the properties of a relevant substance in a pharmacologically desirable way.
Abstract: The estrogenic flavanone rac -8-prenylnaringenin (8-PN) and 3 derivatives ( rac -7-(O-prenyl)naringenin-4′-acetate (7-O-PN), rac -5-(O-prenyl)narin

Journal ArticleDOI
TL;DR: In cytotoxicity tests using four human breast cancer cell lines, 1 and 2 were weakly toxic to MCF‐7 cells but showed little activity against MCF•7 cells resistant to doxorubicin or against two oestrogen receptor‐deficient cell lines.
Abstract: Bioassay guided fractionation of the roots of Cyathostemma argenteum using the brine shrimp resulted in the isolation of two uncommon flavanones, 2,5-dihydroxy-7-methoxy flavanone 1 and 2,5-dihydroxy-6,7-dimethoxy flavanone 2 while the stem bark yielded the related compounds 5-hydroxy-7-methoxy flavone 3 and 5-hydroxy-6,7-dimethoxy flavone 4. The alkaloids liriodenine 5 and discretamine 6 as well as benzyl benzoate 7 were isolated from the roots and 6 was also isolated from the stembark. In cytotoxicity tests using four human breast cancer cell lines, 1 and 2 were weakly toxic to MCF-7 cells (IC(50) = 19.6 and 19.0 microM, respectively) but showed little activity against MCF-7 cells resistant to doxorubicin or against two oestrogen receptor-deficient cell lines. Compound 5, but not 6 and 7, was moderately cytotoxic against all four cell lines. These results are discussed in the context of the traditional use of C. argenteum in the treatment of breast cancer.