Note: A new chromone from Ficus lyrata

A new chromone, named 5,6-dihydroxy-2-methylchromone (FL-2), along with seven known flavonoids, 5-hydroxy-7,3,3′,4′-tetramethoxyflavone (FL-3), 5,4′-dihydroxy-6,7,8-trimethoxyflavone (FL-4), 5,4′-dihydroxy-7,8-dimethoxyflavone (FL-5), 4-methoxychalcone (FL-6), 7,4′-dimethoxyapigenin (FL-7), 5,7,4′-trihydroxy-2′,3′,6′-trimethoxyisoflavone (FL-8?a rare flavonoid), acacetin-7-O-glucoside (FL-9) and acacetin-7-O-neohesperidoside (FL-10), and β-sitosterol-d-glucoside (FL-1) have been isolated from the leaves of Ficus lyrata. Their structures have been established on the basis of chemical and spectral evidence (IR, UV, ¹H NMR, ¹³C NMR and mass spectra).     

Flavonoids from the leaves of Pleioblastus argenteastriatus

A new flavonoid, 5,7,3'-trihydroxy-6-C-beta-D-digitoxopyranosyl-4'-O-beta-D-glucopyranosyl flavonoside (1), along with four known flavonoids 5,7,4'-trihydroxy-3',5'-dimethoxy flavone (2), 5,3',4'-trihydroxy-7-O-beta-D-glucopyranosyl flavonoside (3), 5,4'-dihydroxy-3',5'-dimethoxy-7-O-beta-D-glucopyranosyl flavonoside (4), 5,3',4'-trihydroxy-6-C-[beta-D-glucopyranosyl-(1 --> 6)]-beta-D-glucopyranosyl flavonoside (5) were isolated from 95% EtOH extract of the leaves of Pleioblastus argenteastriatus. Their structures were determined on the basis of spectroscopic techniques and chemical methods.     

New dihydrochalcones and anti-platelet aggregation constituents from the leaves of Muntingia calabura

Two new dihydrochalcones, 2,3-dihydroxy-4,3',4',5'-tetramethoxydihydrochalcone (1) and 4,2',4'-trihydroxy-3'-methoxydihydrochalcone (2), and a new flavanone, (2R,3R)-(-)-3,5-dihydroxy-6,7-dimethoxyflavanone (3), together with nineteen known compounds have been isolated from the leaves of Muntingia calabura. The structures of three new compounds were determined through spectral analyses including extensive 2D-NMR data. Among the isolates, 2,3-dihydroxy-4,3',4',5'-tetramethoxydihydrochalcone, 5,7-dihydroxy-3-methoxyflavone, 5,7-dihydroxy-6-methoxyflavone, 5,4'-dihydroxy-3,7-dimethoxyflavone, (2S)-7,8,3',4',5'-pentamethoxyflavan, (2S)-5'-hydroxy-7,8,3',4'-tetramethoxyflavan, and methyl gallate exhibited significant anti-platelet aggregation activity in vitro.     

Three new C-flavonoids from Corallodiscus flabellata

Three new C-glycosylflavones, named 5,7,4'-trihydroxy-6-methoxy-8-C-[beta-D-xylopyranosyl- (1 --> 2)]-beta-D-glucopyranosyl flavonoside (1), 5,7,4'-trihydroxy-8-methoxy-6-C-[beta-D-xylopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl flavonoside (2), and 5,3',4'-trihydroxy-7,8-dimethoxy-6-C-[beta-D-xylopyranosyl-(1 --> 2)]-beta-D-glucopyranosyl flavonoside (3), along with two known compounds 5,4'-dihydroxy-7-methoxy-6-C-glucopyranosyl-flavonoside (4), 3-methoxy-4-hydroxymethyl benzoate (5) were isolated from 70% acetone extract of Corallodiscus flabellata. Their structures were identified on the basis of spectroscopic techniques and chemical methods.     

穿心莲根的化学成分研究

为研究常用中药爵床科植物穿心莲(Andrographis paniculata)根的化学成分,运用各种色谱方法从安徽临泉产穿心莲根的80%乙醇提取物中分离并鉴定了28个化合物,其中20个黄酮:5,5'-二羟基-7,8,2'-三甲氧基黄酮(1)、5-羟基-7,8,2',6'-四甲氧基黄酮(2)、5,3'-dihydroxy-7,8,4',-trimethoxyflavone(3)、2'-羟基-5,7,8-三甲氧基黄酮(4)、5-羟基-7,8,2',3',4'-五甲氧基黄酮(6)、wightin(7)、5,2',6'-trihydroxy-7-methoxyflavone 2'-O-β-D-glucopyranoside(8)、5,7,8,2'-四甲氧基黄酮(10)、5-羟基-7,8-二甲氧基二氢黄酮(11)、5-羟基-7,8-二甲氧基黄酮(12)、5,2'-二羟基-7,8-二甲氧基黄酮(13)、5-羟基-7,8,2',5'-四甲氧基黄酮(14)、5-羟基-7,8,2',3'-四甲氧基黄酮(15)、5-羟基-7,8,2'-三甲氧基黄酮(16)、5,4'-二羟基-7,8,2',3'-四甲氧基黄酮(17)、二氢黄芩新...     

Phytochemical investigation of Anaphalis lactea

Four new compounds, 2',6'-dihydroxy-3'-(2-hydroxy-3-methyl-3-butenyl)-4'-methoxychalcone ( 1), 4,6-dihydroxy-7-isobutyryl-5-prenyl-2(3 H)-benzofuranone ( 4), 7- O-(beta- D-glucopyranosyloxy)-5-hydroxy-1(3 H)-isobenzofuranone ( 6) and (2 R,3 S)-3-methyl-2-(5-oxo-2-isopropenylhexyl)-cyclopentanone ( 7), along with thirteen known compounds were isolated from the whole plant of Anaphalis lactea. Their structures were established based on spectroscopic methods including IR, UV, MS, CD, 1 D NMR and 2 D NMR techniques. Compounds 2, 4 - 6 and 8 - 16 were tested for free-radical scavenging properties in the DPPH assays.     

Antiproliferative constituents in plants 10. Flavones from the leaves of Lantana montevidensis Briq. and consideration of structure-activity relationship

The flavonoid fraction from the leaves of Lantana montevidensis Briq. (Verbenaceae) showed antiproliferative activity against human gastric adenocarcinoma (MK-1, GI50: 12 microg/ml), human uterus carcinoma (HeLa, 5 microg/ml), and murine melanoma (B16F10, 5 microg/ml) cells in vitro. Bioactivity-guided chemical investigation of the fraction has resulted in the isolation of apigenin (10) and ten 5,6,7-oxygenated flavones: cirsilineol (1), eupatorin (2), 5,4'-dihydroxy-6,7,3',5'-tetramethoxyflavone (3), 5,6-dihydroxy-7,3',4'-trimethoxyflavone (4), 5,6,4'-trihydroxy-7,3',5'-trimethoxyflavone (5), 5,6,3'-trihydroxy-7,4'-dimethoxyflavone (6), 5,3',4'-trihydroxy-6,7,5'-trimethoxyflavone (7), cirsiliol (8), hispidulin (9), and eupafolin (11). Antiproliferative activity of the isolated flavones, some other related flavones (luteolin, baicalein, 6-hydroxyluteolin, pectolinarigenin, jaceosidin, desmethoxycentaureidin, eupatilin, and chrysin) from other plant materials, and synthetic 6- and 7-methoxyflavones was evaluated, and the structure-activity relationships were examined.     

Flavonoids and stilbenoids with COX-1 and COX-2 inhibitory activity from Dracaena loureiri

Fom the stem wood of Dracaena loureiri, a new homoisoflavanone named loureiriol (1) and eight known flavonoid and stilbenoid derivatives, including 5,7-dihydroxy-3-(4-hydroxybenzyl)-4-chromanone (2), 4,4'-dihydroxy-2,6-dimethoxydihydrochalcone (3), 2,4'-dihydroxy-4,6-dimethoxydihydrochalcone (4), 4'-hydroxy-2,4,6-trimethoxydihydrochalcone (5), 4,6,4'-trihydroxy-2-methoxydihydrochalcone (6), 4,3',5'-trihydroxystilbene (7), 4,3'-dihydroxy-5'-methoxystilbene (8) and 4-hydroxy-3',5'-dimethoxystilbene (9) were isolated. These compounds were evaluated for their inhibitory activity against the enzymes cyclooxygenase-1 and cyclooxygenase-2. Potent but non-selective activity was found for the stilbenoids 7-9 (IC(50) 1.29 - 4.92 microM) whereas weak or no activity was observed for the flavonoids 1-6.     

A new meta-homoisoflavane from the fresh stems of dracaena cochinchinensis

A new meta-homoisoflavane, 10,11-dihydroxydracaenone C (1), together with 7,4'-dihydroxyflavone (2), 7,4'-dihydroxyflavane (3), 4,4'-dihydroxy-2-methoxychalcone (4), 4,4'-dihydroxy-2-methoxydihydrochalcone (5), 7,4'-dihydrohomoisoflavanone (6), 7,4'-homoisoflavane (7), lophenol (8), beta-sitosterol (9), stigma-5, 22-diene-3-ol (10), 1-(4'-O-beta-D-glucopyranosyl)benzyl-ethan-2-ol (11), 3,4-dihydoxy-1-allylbenezene-4-O-alpha-L-rhamnopyranosyl-(1 --> 6)-O-beta-D-glucopyranoside (12), 1-hydroxy-3,4,5-trimethoxybenzene-1-O-alpha-L-apiopyranosyl-(1 --> 6)-O-beta-D-glucopyranoside (13), and tachioside (14) have been isolated from the fresh stems of Dracaena cochinchinensis. Their structures have been established by spectroscopic analysis, especially by 2D NMR. This is the first time compounds 11, 13, 14 have been isolated from Dracaena.     

Chemical constituents from Belamcanda chinensis

One new flavone and one new isoflavone glycoside were isolated along with 15 known compounds from the rhizome of Belamcanda chinensis (Iridaceae), and their structures were characterised as 5,4'-dihydroxy-6,7-methylenedioxy-3'-methoxyflavone (1) and 3',5'-dimethoxy irisolone-4'-O-beta-D-glucoside (2) on the basis of spectroscopic methods.     

New prenylchalcones from the hops of Humulus lupulus

Two new prenylchalcones, xanthohumol C and D, together with two known prenylchalcone derivatives, xanthohumol (1) and 5'-(2'-hydroxyisopropyl)-dihydrofurano-[2',3'-b]-4,4'-dihydroxy-6'-methoxy-chalcone (4) were isolated and identified from the hops of Humulus lupulus L. The structures of xanhohumol C and D were elucidated as 5'-hydroxy-6',6'-dimethyl-dihydropyrano-[2',3'-b]-4,4'-dihydroxy-6'-methoxy-chalcone (2) and 5'-hydroxy-6',6'-dimethyl-dihydropyrano-[2',3'-b]-4',6'-dimethoxy-4-hydroxy-chalcone (3) on the basis of HRFAB-MS, 1D and 2D NMR (HMQC, HMBC) spectroscopic data. Among the new prenylchalcones, compound 2 showed marginal cytotoxic activity against human stomach carcinoma BGC-823 and human hepatic carcinoma HepG2 cells.     

5'-Hydroxydigipenstroside and Penstriatoside: Novel Dimeric and Trimeric Open-Chain Monoterpene Glucosides from Penstemon digitalis*

A new dimeric open-chain monoterpene glucoside, 5'-hydroxydigipenstroside {1-beta- D-glucopyranosyl)-8-[5',8'-dihydroxy-2',6'-dimethyl-2'( E),6'( E)-octadienoyl]-5,8-dihydroxy-2,6-dimethyl-2( E),6( E)-octadienoate} has been isolated from leaves of PENSTEMON DIGITALIS Nutt. In addition, the novel trimeric open-chain monoterpene glucoside penstriatoside {1-(beta- D-glucopyranosyl)-8-[5',8'-dihydroxy-2',6'-dimethyl-2'( E),6'( E)-octadienoyl-8'-(5',8'-dihydroxy-2',6'-dimethyl-2' ( E)6'( E)-octadienoyl)]-5,8-dihydroxy-2,6-dimethyl-2 ( E),6( E)-octadienoate} has been encountered. The structures of both compounds have been elucidated by spectroscopic means (FD-, FAB-mass, (1)H-, (13)C-NMR, COSY, DEPT).     

Antimycobacterial activity and cytotoxicity of flavonoids from the flowers of<Emphasis Type="Italic">Chromolaena odorata</Emphasis>

From the flowers of Chromolaena odorata (Eupatorium odoratum) four flavanones, isosakuranetin (5,7-dihydroxy-4'-methoxyflavanone) (1), persicogenin (5,3'-dihydroxy-7,4'-dimethoxyflavanone) (2), 5,6,7,4'-tetramethoxyflavanone (3) and 4'-hydroxy-5,6,7-trimethoxyflavanone (4), two chalcones, 2'-hydroxy-4,4',5',6'-tetramethoxychalcone (5) and 4,2'-dihydroxy-4',5',6'-trimethoxychalcone (6), and two flavones, acacetin (5,7-dihydroxy-4'-methoxyflavone) (7) and luteolin (5,7,3',4'-tetrahydroxyflavone) (8) were isolated and identified. Compound 1 exhibited moderate antimycobacterial activity against Mycobacterium tuberculosis with the MIC value of 174.8 microM, whereas compounds 4, 7, and 8 exhibited weak activity with the MIC values of 606.0, 704.2 and 699.3 microM respectively. Compound 7 showed moderate cytotoxicity against human small cell lung cancer (NCI-H187) cells with the MIC value of 24.6 microM, whereas compound 8 exhibited moderate toxicity against NCI-H187 cells and week toxicity against human breast cancer (BC) cells with the MIC values of 19.2 and 38.4 microM respectively.     

Flavonoids from Iris songarica and their antioxidant and estrogenic activity

A new dihydroflavonol, songaricol ( 1) and seven known flavonoids, ayamenin A ( 2), irisflavone A ( 3), 5,7-dihydroxy-2',6-dimethoxyisoflavone ( 4), irilin B ( 5), 5,3'-dihydroxy-7,8,2'-trimethoxyisoflavone ( 6) and irisoid A ( 7) were isolated from rhizome and roots of IRIS SONGARICA. Structure elucidation of 1 was achieved through extensive NMR and circular dichroism techniques. Compounds 1, 5 and 7 showed antioxidant activity in HL-60 cells (IC50 values of 21, 11 and 3.8 microg/mL), whereas 2, 5 and the previously isolated irisone B were able to show estrogenic response (EC50 values of 305.5, 159.7 and 322.0 microg/mL) in yeast cells expressing human estrogen receptor (ER-alpha).     

Cytotoxic chalcones and flavonoids from the leaves of Muntingia calabura

Two new dihydrochalcones, 2',4'-dihydroxy-3'-methoxydihydrochalcone, (-)-3'-methoxy-2',4',beta-trihydroxydihydrochalcone, a new flavanone, (2 S)-(-)-5'-hydroxy-7,3',4'-trimethoxyflavanone, and a new flavonol derivative, muntingone, along with sixteen known compounds, were isolated from the leaves of Muntingia calabura. The structures of these new compounds were determined using spectral analyses including extensive 2D NMR data. Among the isolates, (2 S)-5'-hydroxy-7,3',4'-trimethoxyflavanone, 4'-hydroxy-7-methoxyflavanone, 2',4'-dihydroxychalcone, and 2',4'-dihydroxy-3'-methoxychalcone exhibited cytotoxicity (IC (50) values < 4 microg/mL) against P-388 and/or HT-29 cell lines in vitro.     

A new phenolic compound with anticancer activity from the wood of Millettia leucantha

A new phenolic compound, 1-(3-hydroxy-4-methoxyphenyl)-3-(2,4-dihydroxy-5-methoxyphenyl) propan-1-ol, named as millettinol (1), along with six known compounds, medicarpin (2), 4-hydroxy-3-methoxy-8,9-methylenedioxypterocarpan (3), 5,4'-dihydroxy-7,8-dimethoxyisoflavone (4), physcion (5), (R)-(-)-mellein (6) and isoliquiritigenin (7), were isolated from the wood of Millettia leucantha. The structures of the compounds were determined by an analysis of their spectroscopic data. Some of the isolates were tested for anticancer activity. Compound 1 exhibited strong cytotoxicity against the BCA-1 tumor cell lines with an IC(50) = 3.44 μg/mL.     

Identification of the metabolites of episesamin in rat bile and human liver microsomes

Episesamin is an isomer of sesamin, resulting from the refining process of non-roasted sesame seed oil. Episesamin has two methylendioxyphenyl groups on exo and endo faces of the bicyclic skeleton. The side methylendioxyphenyl group was metabolized by cytochrome-P450. Seven metabolites of episesamin were found in rat bile after treatment with glucuronidase/arylsulfatase and were identified using NMR and MS. The seven metabolites were (7α,7'β,8α,8'α)-3,4-dihydroxy-3',4'-methylenedioxy-7,9':7',9-diepoxylignane (EC-1-1), (7α,7'β,8α,8'α)-3,4-methylenedioxy-3',4'-dihydroxy-7,9':7',9-diepoxylignane (EC-1-2) and (7α,7'β,8α,8'α)-3,4:3',4'-bis(dihydroxy)-7,9':7',9-diepoxylignane (EC-2), (7α,7'β,8α,8'α)-3-methoxy-4-hydroxy-3',4'-methylenedioxy-7,9':7',9-diepoxylignane (EC-1m-1), (7α,7'β,8α,8'α)-3,4-methylenedioxy-3'-methoxy-4'-hydroxy-7,9':7',9-diepoxylignane (EC-1m-2), (7α,7'β,8α,8'α)-3-methoxy-4-hydroxy-3',4'-dihydroxy-7,9':7',9-diepoxylignane (EC-2m-1) and (7α,7'β,8α,8'α)-3,4-dihydroxy-3'-methoxy-4'-hydroxy-7,9':7',9-diepoxylignane (EC-2m-2). EC-1-1, EC-1-2 and EC-2 were also identified as metabolites of episesamin in human liver microsomes. These results suggested that similar metabolic pathways of episesamin could be proposed in rats and humans.     

Antifungal chalcones from Maclura tinctoria

Five prenylated flavonoids, including one new natural product, were isolated from an ethanol extract of the leaves of Maclura tinctoria (L.) Gaud. The new compound has been characterized as 2',4',4,2'-tetrahydroxy-3'-[3'-methylbut-3'-enyl]chalcone (1). The known compounds were identified as 2',4',4-trihydroxy-3'-[3'-methylbut-3'-enyl]chalcone (isobavachalcone) (2), 4,2'-dihydroxy-2'-[1-hydroxy-1-methylethyl]-2',3'-dihydrofurano[4',5':3',4']chalcone (bakuchalcone) (3), 4,4',5'-trihydroxy-6',6'-dimethyldihydropyrano[2',3':5',6']chalcone (bavachromanol) (4), and 5,7,3',4'-tetrahydroxy-6,8-diprenylisoflavone (6,8-diprenylorobol) (5). All the isolated compounds were evaluated against the AIDS-related opportunistic fungal pathogens, Candida albicans and Cryptococcus neoformans. Compound 2 was active against both yeasts.     

9, 10-Dihydrophenanthrene derivatives from Pholidota yunnanensis and scavenging activity on DPPH free radical

Three new 9,10-dihydrophenanthrene derivatives named phoyunnanins A-C, together with six known 9,10-dihydrophenanthrene constituents, 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,1'-biphenanthrene (4), lusianthridin (5), eulophiol (6), 2,4,7-trihydroxy-9,10-dihydrophenanthrene (7) and imbricatin (8), were isolated from the 60% ethanolic extract of air-dried whole plant of Pholidota yunnanensis Rolfe. The structures of phoyunnanins A-C were established as 6-[2'-(3',3'-dihydroxy-5'-methoxybibenzy)]-4,7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (1), 6-[6'-(trans-3',3'-dihydroxy-5'-methoxystilbeny)]-4,7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (2) and 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,6'-biphenanthrene (3), respectively, on the basis of the spectroscopic analysis. All eight compounds (1-8) were found to show the DPPH free radical scavenging activity with EC₅₀ from 8.8 to 55.9 μM.     

Flavonoids from Pterocaulon alopecuroides with antibacterial activity

Three flavonoids, (2 R,3 R)-5,4'-dihydroxy-3'- O-methyl-7-(gamma,gamma-dimethylallyloxy)dihydroflavonol 1, (2 R,3 R)-5,7,4'-trihydroxy-3'- O-methyl-6-(alpha,alpha-dimethylallyl)dihydroflavonol 2, and (2 R,3 R)-5,7,4'-trihydroxy-6-(alpha,alpha-dimethylallyl)dihydroflavonol 3, together with three known flavonoids ( 4 - 6), were isolated from the aerial parts of PTEROCAULON ALOPECUROIDES. The structures of the compounds were determined by mass and by 1 D and 2 D NMR spectroscopy. Screening of the antibacterial activity of all six compounds was conducted by a disc diffusion test against BACILLUS CEREUS, BACILLUS SUBTILIS, SALMONELLA TYPHIMURIUM and PROTEUS MIRABILIS. The minimum inhibitory concentration (MIC) of the active compounds ( 2, 3, 4, 6) was determined by a microdilution assay. These compounds were active only against both Gram+ bacteria with MIC values < or = 200 microg/mL.