A new auronol from Cudrania cochinchinensis

A new auronol, cudrauronol (1), was isolated from the roots of Cudrania cochinchinensis along with 10 known compounds, 1,3,5-trihydroxy-4-prenylxanthone (2), 1,3,7-trihydroxy-4-prenylxanthone (3), 3,4′,5,7-tetrahydroxydihydroflavonol (4), kaempferol (5), 3,6-dihydroxy-1,5-dimethoxyxanthone (6), 2′,4′,5,7-tetrahydroxyflavanolol (7), 3,7-dihydroxy-1-methoxyxanthone (8), 1,3,5-trihydroxyxanthone (9), cudraflavone B (10), and 2′-oxyresveratrol (11). Compounds 1–8 were evaluated for anti-inflammatory activity on lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages. Compounds 2–5 were more active than aminoguanidine, with IC₅₀ values of 8.8, 23.2, 27.1, and 11.9 μM, respectively.     

Natural products inhibiting Candida albicans secreted aspartic proteases from Tovomita krukovii

Assay-guided fractionation of the ethanol extract of Tovomita krukovii resulted in the identification of four new xanthones (1 - 4) and ten known compounds (5 - 14). The structures of compounds 1 - 14 were determined by spectral data to be 3,5-dihydroxy-4-methoxyxanthone (1), 1,3,5,7-tetrahydroxy-8-isoprenylxanthone (2), 1,3,5-trihydroxy-8-isoprenylxanthone (3), 1,5,7-trihydroxy-8-isoprenylxanthone (4), 1,3,7-trihydroxy-2-isoprenylxanthone (5), 1,5-dihydroxyxanthone (6), 1,6-dihydroxy-5-methoxyxanthone (7), 1,3,5-trihydroxyxanthone (8), 1,3,6-trihydroxy-5-methoxyxanthone (9), 1,6-dihydroxy-3,5-dimethoxyxanthone (10), 1,3,7-trihydroxyxanthone (11), 3-geranyl-2,4,6-trihydroxybenzophenone (12), betulinic acid (13), and 3,4-dihydroxybenzoic acid (14). Compounds 2, 3, 12 and 13 showed inhibitory effects against Candida albicans secreted aspartic proteases (SAP) with IC50 values of 15 microg/ml, 25 microg/ml, 40 microg/ml, and 6.5 microg/ml, respectively, while the other compounds were inactive. In addition, compound 12 showed activity against C. albicans, C. neoformans, S. aureus and methicillin resistant S. aureus (MRS).     

New isoflavones, inhibiting catechol-O-methyltransferase, produced by Streptomyces.

In the screening of catechol-O-methyltransferase inhibitors in streptomyces culture filtrates, three new isoflavones were isolated. Their structures were shown to be 3',5,7-trihydroxy-4',6-dimethoxyisoflavone (I), 3',5,7-trihydroxy-4',8-dimethoxyisoflavone (II), 3',8-dihydroxy-4',6,7-trimethoxyisoflavone (III). I and II inhibited both catechol-O-methyltransferase and dopa decarboxylase, and showed hypotensive action. III was a specific inhibitor of catechol-O-methyltransferase, and showed no hypotensive action.     

Xanthones from the roots of Cudrania fruticosa Wight

Chemical investigation on the roots of Cudrania fruticosa resulted in the isolation of two new xanthones, 1,6,7-trihydroxy-2-(1,1-dimethyl-2-propenyl)-3-methoxyxanthone (1) and 3,6,7-trihydroxy-1-methoxyxanthone (2), together with three known ones, 1,3,5-trihydroxy-4-(3-hydroxy-3-methylbutyl)xanthone (3), 1,3-dihydroxy-6,7-dimethoxyxanthone (4) and 3,5,6-trihydroxy-1-methoxyxanthone (5), respectively. Their structures were elucidated on the basis of spectral and chemical techniques.     

Bioactive coumarin derivatives from the fern Cyclosorus interruptus

Three new coumarin derivatives, compounds 1-3, three new furanocoumarins, compounds 4-6, and a novel dioxocane derivative, compound 7, were isolated from the fern Cyclosorus interruptus (Willd.) H. It?. Based on spectrometric and spectroscopic analysis (FAB or El mass spectrometry as well as 1D and 2D NMR experiments) their structures were characterised as 5,7-dihydroxy-6-methyl-4-phenyl-8-(3-phenylpropionyl)-1-benzopyran-2-one (1), 5,7-dihydroxy-6-methyl-4-phenyl-8-(3-phenyl-trans-acryloyl)-1- benzopyran-2-one (2), 5,7-dihydroxy-8-(2-hydroxy-3-phenylpropionyl)-6-methyl-4-phenyl-1- benzopyran-2-one (3), 8-benzyl-5,8-dihydroxy-6-methyl-4-phenylfuro[2,3-h]-1-benzopyran-2,9- dione (4), 8-benzyl-5,8 beta,9 beta-trihydroxy-6-methyl-4-phenyl-8,9-dihydro- furo[2,3-h]-1-benzopyran-2-one (5), 8-benzyl-5,8 beta,9 alpha-trihydroxy-6-methyl-4-phenyl-8,9-dihydro- furo[2,3-h]-1-benzopyran-2-one (6) and 5,11-dihydroxy-6-methyl-4-phenyl-11-(1-phenylmethyl)-7,10-dioxocane [5,6-h]-1-benzopyran-2,12-dione (7). For these compounds we propose the trivial names interruptins A-F. Compounds 1, 5/6 and 7 showed antibacterial activity while compounds 1 and 2 were cytotoxic to a KB cell line.     

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.     

New flavonol glycosides and new xanthone from Polygala japonica

Three new flavonol glycosides and a new xanthone were isolated from Polygala japonica HOUTT. with eight known compounds. Their structures were identified as 1,7-dihydroxy-3,4-dimethoxy-xanthone (1), kaempferol-7,4'-dimethyl ether (2), physcion (3), guazijinxanthone (4), rhamnetin (5), polygalin A (6), 3,5,7-trihydroxy-4'-methoxy-flavone-3-O-beta-d-galactopyranoside (7), 3,5,3'-trihydoxy-7,4'-dimethoxy-flavone-3-O-beta-d-galactopyranoside (8), 3,5,3',4'-tetrahydroxy-7-methoxy-flavone-3-O-beta-d-galactopyranoside (9), 3,5,3',4'-tetrahydroxy-7-methoxy-flavone-3-O-beta-d-glucopyranoside (10), polygalin B (11), polygalin C (12). Among them, compound 4 is a new xanthone, and 6, 11 and 12 are new flavonol glycosides. Compounds 1, 4, 7 and 8 were tested for cytotoxic activity with MTT assays on five human tumor cell lines, K562, A549, PC-3M, HCT-8 and SHG-44. Compound 4 showed cytotoxic activity against all the five cell lines.     

A New Isoflavone Glycoside from Dalbergia vacciniifolia (Fabaceae)

5,5'-Dihydroxy-2',4'-dimethoxy-7-[(6-O-β-d-apiofuranosyl-β-d-glucopyranosyl)-oxy]isoflavone (1) was isolated as the major constituent of Dalbergia vacciniifolia root bark ethanol extract together with the four known compounds 5,7-dihydroxy-2',4',5'-trimethoxyisoflavone (3), 5,7-dihydroxy-2',4'-dimethoxy-isoflavone (4), 5-hydroxy-2',4',7-trimethoxyisoflavone (5) and 7-hydroxy-2',4',5'-trimethoxyisoflavone (6). Identification of compounds was achieved through extensive analysis of 1D and 2D NMR and MS spectroscopy.     

Xanthones from the roots of Cudrania fruticosa Wight

Chemical investigation on the roots of Cudrania fruticosa resulted in the isolation of two new xanthones, 1,6,7-trihydroxy-2-(1,1-dimethyl-2-propenyl)-3-methoxyxanthone (1) and 3,6,7-trihydroxy-1-methoxyxanthone (2), together with three known ones, 1,3,5-trihydroxy-4-(3-hydroxy-3-methylbutyl)xanthone (3), 1,3-dihydroxy-6,7-dimethoxyxanthone (4) and 3,5,6-trihydroxy-1-methoxyxanthone (5), respectively. Their structures were elucidated on the basis of spectral and chemical techniques.     

Structural elucidation of a new flavone from Sarcopyramis nepalensis

A novel flavone, named 4'-methoxy-3',5,7-trihydroxy-8-(1'-(3',4',5'-trihydroxyphenyl)ethyl)flavone (1), was isolated from Sarcopyramis nepalensis, along with two known compounds syringaresinol (2) and aralidioside (3). Their structures were established by the spectroscopic analysis, especially by 2D NMR. All of the three compounds were isolated from the plant for the first time.     

Antioxidative 7-oxodehydropodocarpane-type trinorditerpenes from the bark of Taiwania cryptomerioides

Five new 7-oxopodocarpane-type trinorditerpenes together with 1beta,13,14-trihydroxy-8,11,13-podocarpatrien-7-one ( 1) were isolated from the bark of Taiwania cryptomerioides. By using NMR and other spectral methods, the structures of five new compounds, 14-hydroxy-13-methoxy-8,11,13-podocarpatriene-3,7-dione ( 2), 1beta,14-dihydroxy-13-methoxy-8,11,13-podocarpatrien-7-one ( 3), 13,14-dihydroxy-8,11,13-podocarpatriene-3,7-dione ( 4), 3beta,13,14-trihydroxy-8,11,13-podocarpatrien-7-one ( 5), and 1beta,13,14-trihydroxy-8,11,13-podocarpatriene-2,7-dione ( 6), were elucidated. Compounds 1, 4, 5, and 6 exhibited strong antioxidative activity.     

New terpenoids from Haplopappus multifolius

The chemical investigation of the aerial parts of Haplopappus multifolius afforded the new monoterpene 2,9-epoxy-p-menth-6-en-8-ol (7, haplopappol), the new monoterpenoid ester 9-cis-p-coumaroyloxy-alpha-terpineol (8, haplofolin), the new diterpene 18-hydroxylabda-7,13Z-dien-15-oic acid (6) and its known E-isomer (5). In addition, the known dihydroflavones 3',5-dihydroxy-4',7-dimethoxydihydroflavone and 3',4',5-trihydroxy-7-methoxydihydroflavone and the known dihydroflavonols 3',5-dihydroxy-4',7-dimethoxydihydroflavonol and 3',4',5-trihydroxy-3-acetyl-7-methoxydihydroflavonol were also obtained. The structural assignments of these compounds were made possible by the different spectroscopic measurements.     

Flavonoid constituents of Melicope triphylla MERR.II

From the leaves of Melicope triphylla MERR., three new flavonoids (1-3) were isolated, together with nine known flavonoids, 4',5-dihydroxy-3,3',7- trimethoxyflavone (4), 5-hydroxy-3,3',4',7-tetramethoxyflavone (5), 3,3',4',5,7-pentamethoxyflavone (6), 7-hydroxy-3,3',4',5,8-pentamethoxyflavone (7), 3,3',4',5,7,8-hexamethoxyflavone (8), 5-hydroxy-3,7,8-trimethoxy-3',4'-methylenedioxyflavone (9), 7-hydroxy-3,5,8- trimethoxy-3',4'-methylenedioxyflavone (10), 3,5,7,8-tetramethoxy-3',4'-methylenedioxyflavone (11), and 5-hydroxy- 3,6,7,8-tetramethoxy-3',4'-methylenedioxyflavone (12). The structures of 1, 2, and 3 were established as 5-hydroxy-3,7-dimethoxy-3',4'-methylenedioxyflavone, 5-hydroxy-7-isopentenyloxy-3,8-dimethoxy-3',4'-methylenedioxyfl avone, and 4'-hydroxy-7-isopentenyloxy-3,3',5,8-tetramethoxyflavone by their respective chemical and spectral data. The 20 flavonoids isolated from this plant were examined for the piscicidal activities.     

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.     

白杨素衍生物的合成和晶体结构及与DNA的作用

以白杨素为先导化合物经羟甲基化反应合成中间体5,7-二羟基-6,8-二羟甲基黄酮(1)，进而合成了5,7-二羟基-6,8-二(甲氧基甲基)黄酮(2)，5,7-二羟基-6,8-二(乙氧基甲基)黄酮(3)，5,7-二羟基-6,8-二(丁氧基甲基)黄酮(4)，5,7-二羟基-6,8-二(戊氧基甲基)黄酮(5)和5-羟基-7-甲氧基-6,8-二(乙氧基甲基)黄酮(6)；采用IR，¹H NMR，¹³C NMR和元素分析对1～6进行了表征，同时用X-射线单晶衍射法对6进行了晶体结构测定。利用荧光法分别对1～4与CT-DNA的作用进行了研究，根据Stern-Volmer方程，它们对EB-DNA体系的荧光猝灭常数分别为k_q1=9.71×10³ L·mol^-1，k_q2=2.25×10⁴L·mol^-1，k_q3=1.03×10⁴L·mol^-1和k_q4=7.96×10³ L·mol^-1。1～4与白杨素相比，对DNA更具亲和力，为开发更有效的黄酮类化合物提供了实验依据。     

Two new isoflavonoids from the roots of Dalbergia congesta (Grah)

A systematic examination of the roots of Dalbergia congesta, yielded a new oligomeric isoflavonoid (1), a new tetramethoxy isoflavone (2) along with two known compounds, an isoflavone dalspinin (3) and a benzophenone, cearoin (4). On the basis of chemical and spectral evidences, compounds 1 and 2 were determined to be 5,7-dihydroxy-6,4'-dimethoxy-6'[2'-hydroxy-2'(2',5'-dimethoxy neoflavonyl) ethenyl] isoflavone (dalcongestin) and 5,7-dihydroxy-2',3',5',6'-tetramethoxy isoflavone, respectively.     

New abietane diterpenoids from the mangrove Avicennia marina

Phytochemical investigations of the twigs of Avicennia marina yielded three new abietane diterpenoids 11-hydroxy-8,11,13-abietatriene 12- O-beta-xylopyranoside ( 1), and a pair of inseparable epimers 6 Halpha-11,12,16-trihydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial 11,6-hemiacetal ( 2) and 6 Hbeta-11,12,16-trihydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial 11,6-hemiacetal ( 3), as well as the new lignan (7' S,8' R)-4,4',9'-trihydroxy-3,3',5,5'-tetramethoxy-7,8-dehydro-9-al-2,7'-cyclolignan ( 5), together with 6,11,12,16-tetrahydroxy-5,8,11,13-abitetetraen-7-one ( 4), lyoniresinol ( 6), lyoniresinol 9'- O-beta- D-glucopyranoside ( 7), and diacetylmartynoside ( 8). Structure elucidation of the new compounds was accomplished by analysis of their spectroscopic data. Compounds 2 - 4 showed moderate cytotoxic and antimicrobial activities.     

A new compound from Gentianopsis paludosa

A new compound, named gentianopfluorenone (1), along with three known compounds,1-O-beta-d-glucopyranosyl-5-hydroxy-3-methoxyxanthone (2), 1-O-[beta-d-xylopyranosyl-(1 --> 6)-beta-d-glucopyranosyl]-7,8-dihydroxy-3-methoxyxanthone (3), and apigenin (4), were isolated from the whole herb of Gentianopsis paludosa. On the basis of spectral and chemical evidence, the structure of 1 was elucidated as 4,4a,6-trihydroxy-5-methoxy-fluoren-2,9-dione. Compounds 2-4 were isolated from the plant for the first time.     

New Flavonoids from Boldoa purpurascens Cav

Phytochemical analysis of the leaves of BOLDOA PURPURASCENS Cav. led to isolation of four flavone glycosides, three of which are new compounds. Their structures have been determined by mass spectrometry and by 1 D and 2 D NMR analysis, i. e., 4',5-dihydroxy-6,7-methylenedioxyflavonol 3- O-alpha- L-rhamnopyranosyl-(1-->2)-beta- D-xylopyranoside ( 1), 4',5-dihydroxy-6,7-methylenedioxyflavonol 3- O-beta- D-xylopyranoside ( 2), and 4',5-dihydroxy-6,7-methylenedioxyflavonol 3- O-alpha- L-rhamnopyranosyl-(1-->2)-beta- D-glucopyranoside ( 3). The known compound was 4',5-dihydroxy-6,7-methylenedioxyflavonol 3- O-beta- D-glucopyranoside ( 4). The aglycone 4',5-dihydroxy-6,7-methylenedioxyflavonol is known as gomphrenol. Compounds 1 and 2 failed to show antifungal activity when tested against three different strains of fungi, i. e., FUSARIUM CULMORUM, BOTRYTIS CINEREA, and ASPERGILLUS FLAVUS.