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.     

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 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.     

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 IC(50) values of 8.8, 23.2, 27.1, and 11.9?μM, respectively.     

Two new flavonoid glycosides from Artemisia frigida Willd

An investigation of the n-BuOH-soluble fraction from the aerial parts of Artemisia frigida has led to the isolation of two new flavonoid glycosides, named friginoside A and friginoside B. Their structures were characterized as 5,7-dihydroxy-3',4',5'-trimethoxy flavone 7-O-β-d-glucuronide (1) and 5,7-dihydroxy-3',4',5'-trimethoxyflavone 7-O-β-d-glucuronyl-(1?→?2)O-β-d-glucuronide (2) on the basis of 1D and 2D NMR spectral analysis.     

红花岩黄芪黄酮类成分研究

目的对红花岩黄芪化学成分进行研究。方法用溶剂法、色谱法提取分离化学成分,用波谱法鉴定其结构。结果从红花岩黄芪中分离得到6个化合物：β-谷甾醇(1),芒柄花素(7羟基-4′-甲氧基异黄酮)(2),白桦脂酸(3),1,7-二羟基-3,9-二甲氧基紫檀烯(4),5,7-二羟基-4′-甲氧基-8-异戊烯基异黄酮(5)和金雀花异黄素(5,7-二羟基-4′-甲氧基异黄酮)(6)。结论化合物4为新化合物,其他均为首次从该植物中获得。     

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.     

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.     

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.     

Two novel flavans from Cyperus conglomeratus

Separation of the extract of the underground tubers of Cyperus conglomeratus Rottb. (family Cyperaceae) afforded, in addition to known compounds, two novel flavans, which were identified, by one and two dimensional NMR, MS and IR spectra, as 5-hydroxy-7,3',5'-trimethoxyflavan and 5,7-dihydroxy-3',5'-dimethoxy-6-prenylflavan.     

Tenuiflorins A-C: new 2-phenoxychromones from the leaves of Mimosa tenuiflora

Five 2-phenoxychromones, the new tenuiflorin A [5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenoxy)-6-methoxychromone], tenuiflorin B [5,7-dihydroxy-2-(4-hydroxy-3-methoxyphenoxy)-6-methoxychromone] and tenuiflorin C [5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenoxy)chromone], along with the known 6-demethoxycapillarisin and 6-demethoxy-4'- O-methylcapillarisin were isolated from leaves of Mimosa tenuiflora. Structures of these compounds were established by analysis of their spectroscopic data. A single-crystal diffraction analysis of 6-demethoxy-4'- O-methylcapillarisin was performed in order to confirm the proposed structures.     

New citrinin derivatives isolated from Penicillium citrinum

Three new coupling compounds derived from citrinin (9) and 2,3,4-trimethyl-5,7-dihydroxy-2,3-dihydrobenzofuran (8) – penicitrinone A (1), penicitrinol A (2) and penicitrinone B (3) – and a new citrinin derivative – decarboxydihydrocitrinin (4) – were isolated along with 3-methoxy-1-methyl-4(1H)-quinolone (5), quinolactacin A2 (6), dihydrocitrinone (7), 2,3,4-trimethyl-5,7-dihydroxy-2,3-dihydrobenzofuran (8), citrinin (9), quinocitrinin A or B (10), and decarboxydihydrocitrinone (11) from the extract of Penicillium citrinum IFM 53298. The relative structures of compounds 1–4 were confirmed on the basis of spectroscopic investigations and chemical correlations. Citrinin (9) and quinolactacin A2 (6) both showed antifungal activity.     

New cytotoxic prenylated isoflavonoids from Bituminaria morisiana

Using cytotoxicity against KB cancer cells as a lead, bioguided-fractionation of the petroleum ether and ethyl acetate extracts of Bituminaria morisiana leaves led to the isolation of two new pterocarpans, namely 3,9-dihydroxy-4-(3,3-dimethylallyl) [6a R, 11a R]-pterocarpan, 3-hydroxy-4-(3,3-dimethylallyl)-4',5'-dehydropyrano[8,9:2',3'][6a R,11a R]-pterocarpan and one new isoflavone identified as 4',5'-dihydroxy-6'-methoxy-4',4'-dimethyl-4',5'-dihydro-6' H-pyrano[2',3':7,8]-isoflavone. Moreover, two known pterocarpans, erybraedin C and bitucarpin A, three known isoflavones, daidzein, 8-prenyldaidzein and bidwillon C, one known furocoumarin, pseudoisopsoralen and one known coumestan, coumestrol were isolated. The structures of the isolated compounds were established by means of 1D and 2D NMR spectroscopy, as well as mass spectrometry. Further cytotoxicity tests against cells related to the immune system (Jurkat T, Mono-Mac-6 and polymorphonuclear cells) showed a moderate activity of the known pterocarpan erybraedin C against all cell lines used (IC (50) values between 17.6-28.8 microM). In addition, erybraedin C was found to induce necrosis in leukaemia Jurkat T cells.     

Auriculatin 4'-O-Glucoside: A New Prenylated Isoflavone Glycoside from Erythrina eriotricha1

In addition to known compounds, sigmoidin C and 8-(3,3-dimethylallyl)-erythrinin C, also called senegalensin, a new isoflavone glycoside designated auriculatin 4'- O-glucoside was isolated from the chloroform extract of the stem bark of ERYTHRINA ERIOTRICHA. Its structure was elucidated as 7,6-(2',2'-dimethyl-2 H-pyrano)-2',5-dihydroxy-8-(3,3-dimethylallyl)-isoflavone 4'- O-beta- D-glucoside on the basis of spectroscopic methods and chemical evidence.     

Flavonoids with activity against methicillin-resistant Staphylococcus aureus from Dalea scandens var. paucifolia

Bioassay-guided fractionation of the ethyl acetate extract of the roots of Dalea scandens (Miller) R. Clausen var. paucifolia led to the isolation of new flavonoids, 2( S)-5'-(-1"',1"'-dimethylallyl)-8-(3",3"-dimethylallyl)-2',4',5,7-tetrahydroxyflavanone, 2( S)-5'-(1"',1"'-dimethylallyl)-8-(3",3"-dimethylallyl)-2'-methoxy-4',5,7-trihydroxyflavanone and 5'-(1"',1"'-dimethylallyl)-8-(3",3"-dimethylallyl)-2',4',5,7-tetrahydroxyflavone. Structure elucidation was carried out by spectroscopic methods. All three compounds showed significant activity against both methicillin-susceptible and methicillin-resistant Staphylococcus aureus.     

Neoflavonoids from Polygonum perfoliatum

Four neoflavonoids, 3,4-dihydro-4-(4'-hydroxyphenyl)-5,7-dihydroxycoumarin (1), 3,4-dihydro-5-hydroxy-7-methoxy-4-(4'-methoxyphenyl)coumarin (2), 3,4-dihydro-5-hydroxy-4-(4'-hydroxyphenyl)-7-methoxycoumarin (3), and 3,4-dihydro-5,7-dihydroxy-4-(4'-methoxyphenyl)coumarin (4), were isolated from the whole plant of Polygonum perfoliatum. Neoflavonoids 1, 2, and 4 were known compounds, but 3 is a new member of this class.     

粉枝莓中的两种新黄酮成分

为研究粉枝莓(Rubus biflorus Buch)的化学成分，经柱色谱分离，从粉枝莓中分离得到2个黄酮类化合物，光谱分析鉴定其结构为：8-甲基-6-异戊烯基-5,7-二羟基-5′-甲氧基-3′,4′-二氧亚甲基黄酮(A),和8-甲基-5′-异戊烯基-5-甲氧基-6,7-(2″,2″-二甲基吡喃)-3′,4′-二氧亚甲基黄酮(B)，分别命名为粉枝莓素A和粉枝莓素B。化合物A和B为新的黄酮类化合物。     

脱皮马勃化学成分的研究

目的 研究脱皮马勃(Lasiosphaera fenzlii Reich.)的化学成分。 方法 利用各种色谱技术进行分离,根据理化性质和波谱分析鉴定结构。结果 分离鉴定了8个已知化合物,分别是4, 6-二羟基-1(3H)-异苯并呋喃酮(1)、clitocybin A (2)、5, 7-二羟基-1(3H)-异苯并呋喃酮(3)、5-羟甲基糠醛(4)、对苯二酚(5)、3, 5-二羟基苯甲酸(6)、蔗糖(7)和β-谷甾醇(8)。结论 化合物1为首次分离得到的新天然产物,化合物2～7为首次从脱皮马勃中分离得到。     

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.