Flavonol and drimane-type sesquiterpene glycosides of Warburgia stuhlmannii leaves

An investigation of methanolic extract of Warburgia stuhlmannii leaves has led to the isolation of two new drimane-type sesquiterpene glycosides characterized as mukaadial 6-O-beta-D-glucopyranoside, mukaadial 6-O-alpha-L-rhamnopyranoside together with two other novel flavonol glycosides identified as 3',5'-O-dimethylmyricetin 3-O-beta-D-2",3"-diacetylglucopyranoside and 3'-O-methylquercetin 3-O-beta-D-2",3",4"-triacetylglucopyranoside. The known compounds; mukaadial, deacetylugandensolide, quercetin, kaempferol, kaempferol 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-beta-D-glucopyranoside, kaempferol 7-O-beta-D-glucopyranoside, myricetin 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-sophoroside and isorhamnetin 3-O-beta-D-glucopyranoside were also isolated from the same extract.     

Chemical constituents isolated from Polygala japonica leaves and their inhibitory effect on nitric oxide production in vitro

A methanolic extract of dried leaves of Polygala japonica Houtt (Polygalaceae) significantly attenuated nitric oxide production in lipopolysaccharide-simulated BV2 microglia. Five anthraquinones chrysophanol (1), emodin (2), aloe-emodin (3), emodin 8-O-beta-D-glucopyranoside (4) and trihydroxy anthraquinone (5), and four flavonoids kaempferol (6), chrysoeriol (7), kaempferol 3-gentiobioside (8) and isorhamnetin (9) were isolated from the methanolic extract using bioactivity-guided fractionation. Among them, compounds 1-4, 6 and 7 showed significant inhibitory effect on lipopolysaccharide-induced nitric oxide production in BV2 microglia at the concentrations ranging from 1.0 to 100.0 microM.     

The flavonoids of leek, Allium porrum

A phytochemical investigation of the extracts obtained from bulbs of leek. Allium porrum L. has led to the isolation of five flavonoid glycosides based on the kaempferol aglycone. Two of them are new compounds and have been identified as kaempferol 3-O-[2-O-(trans-3-methoxy-4-hydroxycinnamoyl)-beta-D-galactopyranosyl]-(1-->4)-O-beta-D-glucopyranoside, and kaempferol 3-O-[2-O-(trans-3-methoxy-4-hydroxycinnamoyl)-beta-D-glucopyranosyl]-(1-->6)-O-beta-D-glucopyranoside, on the basis of spectroscopic methods, including 2D NMR. The isolated compounds have been evaluated for their human platelet anti-aggregation activity.     

Coumaroyl flavonol glycosides from the leaves of Ginkgo biloba.

Two coumaroyl flavonol glycosides, isorhamnetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside], and kaempferol 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside]-7-O-beta-D-glucopyranoside, were isolated from the n-BuOH extract of Ginkgo biloba leaves. These two, together with six other flavonol glycosides, kaempferol 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside], quercetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside], quercetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside]-7-O-beta-D-glucopyranoside, quercetin 3-O-beta-D-glucopyranosyl-(1-2)-alpha-L-rhamnopyranoside, quercetin 3-O-beta-rutinoside, and quercetin 3-O-beta-D-glucopyranoside, showed profound antioxidant activities in DPPH and cytochrome-c reduction assays using the HL-60 cell culture system.     

Kaempferol triosides from Reseda muricata

A flavonoid trioside and its coumaryl ester together with seven known flavonoids and five phenolic acids were isolated from the leaves of Reseda muricata. Their structures were elucidated by spectroscopic methods including UV, FAB MS, 1H, 13C and 2D-NMR, DEPT, HMBC and HMQC experiments. The two compounds were identified as kaempferol 3-O-beta-D-glucopyranosyl-(1' --> 2')-O-alpha-L-rhamnopyranoside 7-O-beta-D-glucopyranoside and kaempferol 3-O-beta-D-glucopyranosyl-(1' --> 2')-O-alpha-L rhamnopyranoside 7-O-beta-D-(6'-O-E-coumarylglucopyranoside), respectively.     

Ecdysteroid glycosides from Sida rhombifolia L

Seven ecdysteroids, including the three new compounds 1-3, were isolated from Sida rhombifolia L. Their structures and configurations were determined by extensive spectroscopic techniques in combination with chemical derivatization. The four known compounds--ecdysone (4), 20-hydroxyecdysone (5), 2-deoxy-20-hydroxyecdysone-3-O-beta-D-glucopyranoside (6), and 20-hydroxyecdysone-3-O-beta-D-glucopyranoside (7)--are reported for the first time from this plant.     

Microbial transformation of silybin by Trichoderma koningii

Microbial transformation of silybin A (1) and silybin B (2), the major hepatoprotective flavonolignan diastereomers from the fruits of Silybum marianum, with the culture broth of Trichoderma koningii gave two pairs of glucosylated derivatives. Their structures were identified as silybin A 3-O-beta-D-glucopyranoside (3), silybin A 7-O-beta-D-glucopyranoside (4), silybin B 3-O-beta-D-glucopyranoside (5) and silybin B 7-O-beta-D-glucopyranoside (6) by spectroscopic methods.     

A malonylated anthocyanin and flavonols in blue Meconopsis flowers

The structures of the major anthocyanin and two flavonols from the blue flowers of Meconopsis were identified by NMR spectroscopy as being cyanidin 3-O-[(6-O-malonyl-2-O-B-D-xylopyranosyl)-beta-D-glucopyranoside]-7-O-beta-D-glucopyranoside, kaempferol 3-O-(6-O-beta-D-glucopyranosyl)-beta-D-glucopyranoside and kaempferol 3-O-(6-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside respectively.     

Furostanol saponins and quercetin glycosides from the leaves of Helleborus viridis L

Phytochemical analysis of the polar extracts of the leaves of Helleborus viridis (Ranunculaceae) resulted in the isolation of two new furostanol saponins (25R)-26-[(alpha-L-rhamnopyranosyl)oxy]-22alpha-methoxyfurost-5-en-3beta-yl O-beta-D-glucopyranosyl-(1-->3)-O-[6-acetyl-beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranoside (1) and (25R)-26-[(alpha-L-rhamnopyranosyl)oxy]-22alpha-methoxyfurost-5-en-3beta-yl O-beta-D-glucopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->3)-O-beta-D-glucopyranoside (2) and three new quercetin glycosides, quercetin 3-O-(2-E-caffeoyl)-alpha-L-arabinopyranosyl-(1-->2)-beta-D-galactopyranoside-7-O-beta-d-glucopyranoside (3), quercetin 3-O-(2-E-caffeoyl)-alpha-L-arabinopyranosyl-(1-->2)-beta-D-galactopyranoside (4), and quercetin 3-O-alpha-L-arabinopyranosyl-(1-->2)-beta-D-galactopyranoside (5). The structures of the new compounds were determined by spectroscopic analysis, including 2D NMR data and mass spectrometry.     

Iridoids from Globularia dumulosa

Two new iridoids, 10-O-benzoylglobularigenin (1) and dumuloside (2) were isolated from the aerial parts of Globularia dumulosa together with seven known iridoid glucosides, davisioside (3), aucubin (4), melampyroside (5), catalpol (6), 10-O-benzoylcatalpol (7), alpinoside (8) and deacetylalpinoside (9). Three phenylethanoid glycosides, verbascoside, decaffeoyl-verbascoside, leucosceptoside A and three flavone glucosides, pectolinarigenin 7-O-beta-D-glucopyranoside, nepetin 7-O-B-D-glucopyranoside, demethoxycentaureidin 7-O-beta-D-glucopyranoside were also isolated and characterized. The structure elucidation of the isolated compounds was performed by spectroscopic (UV, IR, HR-MALDIMS, 1D- and 2D NMR) methods.     

Aldose-reductase- and protein-glycation-inhibitory principles from the whole plant of Duchesnea chrysantha

Ellagic acid (1), 3,3'-di-O-methylellagic acid (2), 3,3',4-tri-O-methylellagic acid (3), isovitexin (4), kaempferol 3-O-beta-D-glucuronide methyl ester (5), quercetin 3-O-alpha-L-arabinopyranosyl-(1-->6)-beta-D-galactopyranoside (6), ursolic acid, pomolic acid, tormentic acid, euscaphic acid, euscaphic acid 28-O-beta-D-glucopyranoside, and maslinic acid were isolated from the AcOEt- and BuOH-soluble MeOH extract of Duchesnea chrysantha (whole plant). The isolates were subjected to in vitro bioassays to evaluate their inhibitory activity on rat-lens aldose reductase (RLAR) and formation of advanced glycation end products (AGEs). The ellagic acids and flavonoids, compounds 1-6, exhibited moderate inhibitory effects on RLAR. However, compounds 1 and 4-6 showed excellent inhibitory activities towards the formation of AGEs. This is the first report that 4 and 6 exhibit inhibitory activity towards AR and AGEs formation.     

Anti-proliferative and antioxidant constituents from Tecoma stans

Phytochemical investigation of Tecoma stans Juss. fruits and flowers resulted in the isolation of a new phenylethanoid, 2-(3,4-dihydroxyphenyl)ethyl-2-O-[6-deoxy-alpha-L-mannopyranosyl-4-(3,4-dihydroxyphenyl)-2-propenoate]-beta-D-glucopyranoside (3), and a novel monoterpene alkaloid, 5-hydroxy-skytanthine hydrochloride (8), along with eleven known compounds; 4-O-E-caffeoyl-alpha-L-rhamnopyranosyl-(1' --> 3)-alpha/beta-D-glucopyranose (1), E/Z-acetoside (2), isoacetoside (4), rutin (5), luteolin 7-O-beta-D-neohespridoside (6), luteolin 7-O-beta-D-glucopyranoside (7) and sucrose (9) were isolated from the fruits, while luteolin 7-O-beta-D-glucuronopyranoside (10), diosmetin 7-O-beta-D-glucuronopyranoside (11), diosmetin 7-O-beta-D-glucopyranoside (12), diosmetin 7-O-beta-D-glucuronopyranoside methyl ester (13) and acetoside (2) were isolated from the flowers. Their chemical structures have been determined on the basis of chemical and spectroscopic evidences. Biological investigations of a T. stans fruits extract and compounds 1, 2, 4, and 8 indicated that the extract, 1, 2, and 4 possessed a strong scavenging activity to DPPH, peroxyl and hydroxyl radicals. Unlike 4, which potentially induced NO generation in bacterial lipopolysaccharide-stimulated raw murine macrophage (RAW 264.7), the extract, 1, 2, and 8 significantly inhibited the NO generation. The extract, 2 and 4 exhibited a cytotoxic effect on human hepatocarcinoma cells (Hep-G2), while the extract, 2 and 8 were potent growth inhibitors of human breast carcinoma cells (MCF-7). 1 and 2 were remarkable growth inducers of human lymphoblastic leukemia cells (1301), whereas the extract, 2, and 8 stimulated the macrophage proliferation rate. Taken together, the novel compound 8 is effective as anti-proliferative agent against MCF-7 cells and as NO inhibitor, whereas 2 exhibited multi-functional properties as antioxidant and anti-proliferative agent against both solid tumor cell lines Hep-G2 and MCF-7 cells.     

Chemical Constituents from Fruits of Rosa davidii

From the fruit of Rosa davidii Crep., eleven compounds were isolated and identified by spectral evidence, viz. 2α,3β,19β-trihydroxyl-olean-12-en-28-oic acid (1), 2α,3β-dihydroxyl-urs-28(13)-lactone (2), arjunic acid (3), euscaphic acid (4), 2α,3β-dihydroxyl-urs-12-en-28-oic acid (5), oleanolic acid (6), kaempferol (7), tiliroside (8), quercetin (9), daucosterol (10) and β-sitosterol (11). Among them, 1 and 2 were new compounds.     

Triterpenoid saponins and sapogenin lactones from Albizia gummifera

The structures of two new monodesmosidic and bisdesmosidic triterpenoid saponins (1 and 2) and the known compound delta 5-stigmasterol-3-O-beta-D-glucopyranoside (3) as well as two new oleanane type triterpene lactone glycosides 4, 5 and a new sapogenin lactone 6 isolated from the stem bark of Albizia gummifera C.A. Smith (Mimosaceae) have been elucidated as 3-O-?beta-D-glucopyranosyl(1-->2)-[alpha-L-arabinopyranosyl(1-->6) ]-beta-D- glucopyranosyl?-oleanolic acid (1), beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl 3-O-?beta-D-glucopyra-nosyl(1-->2)-[alpha-L-arabinopyrano syl(1-->6)]-beta-D- glucopyranosyl?-oleanolate (2), 3 beta-?O-D-glucopyranosyl-(1-->2)-[O-alpha-L-arabinopyranosyl(1-->6 )] beta-D-glucopyranosyloxy?-machaerinic acid gamma-lactone (4), 3 beta-O-beta-D-glucopyranosiduronic acid (1-->2)-beta-D-glucopyranosyloxy]-machaerinic acid gamma-lactone (5), and A-homo-3a-oxa-5 beta-olean-12-en-3-one-28-oic acid (6), respectively. The complete assignment of the 1H and 13C resonances of 1, 2, 4 and 6 and of the peracetate of 5 were achieved by means of 2D-NMR studies.     

Alkaloids from Portulaca oleracea L

Five alkaloids (oleraceins A, B, C, D and E) were isolated from Portulaca oleracea L., and their structures determined by spectroscopic methods as 5-hydroxy-1-p-coumaric acyl-2,3-dihydro-1H-indole-2-carboxylic acid-6-O-beta-D-glucopyranoside, 5-hydroxy-1-ferulic acyl-2,3-dihydro-1H-indole-2-carboxylic acid-6-O-beta-D-glucopyranoside, 5-hydroxy-1-(p-coumaric acyl-7'-O-beta-D-glucopyranose)-2,3-dihydro-1H-indole-2-carboxylic acid-6-O-beta-D-glucopyranoside, 5-hydroxy-1-(ferulic acyl-7'-O-beta-D-glucopyranose)-2,3-dihydro-1H-indole-2-carboxylic acid-6-O-beta-D-glucopyranoside and 8,9-dihydroxy-1,5,6,10b-tetrahydro-2H-pyrrolo[2,1-a]isoquinolin-3-one, respectively.     

A flavonol triglycoside from Actinidia arguta var. giraldii.

In the course of a chemotaxonomic study of the genus Actinidia a new flavonol triglycoside, quercetin 3-O-beta-D-[2G-O-beta-D-xylopyranosyl-6G-O-alpha-L-rhamnopyranosyl] glucopyranoside was identified amongst the 15 flavonols found in Actinidia arguta var. giraldii. This compound was characterized, along with quercetin 3-O-beta-D-xylopyranosyl-(1-2)-O-beta-D-glucopyranoside, by 1H and 13C NMR spectroscopy. The kaempferol analogues were also isolated.     

天山棱子芹化学成分的研究

从天山棱子芹中首次分离得到15个已知化合物,通过NMR、MS及IR等波谱数据,分别鉴定为6,7-二羟基香豆素(1),( )-marmesin(2),marmesinin(3),5,7,4'-三羟基黄酮(4),莰非醇3-O-α-L-吡喃鼠李糖甙(5),藤黄菌素3'-O-β-D-吡喃葡萄糖甙(6),(R)-6-hydroxy-3-(2-hydroxypropan-2-yl)-6-methylcyclohex-2-enone(7),4-羟基苯甲酸(8),3-甲氧基4羟基苯甲酸(9),3-甲氧基-4,5-亚甲二氧基苯甲酸(10),丁香酸甲酯(11),丁香酸甲酯4-O-β-D-吡喃葡萄糖甙(12),姜油酮4’-O-β-D-吡喃葡萄糖甙(13),2-(4-羟基苯基)-乙醇(14)和正二十八醇(15)。其中化合物7为一新的天然产物。     

Constituents in Easter lily flowers with medicinal activity

Easter lily (Lilium longiflorum) flowers have been used in traditional medicine for alleviating many ailments. However, the chemical basis of its bioactivity has not been investigated. We have determined bioactive components in Easter lily flowers using lipid peroxidation and cyclooxygenase enzyme inhibitory assays and found to be kaempferol (1), kaempferol glycosides (2, 3, 4, 8, 9 and 10), quercetin glycosides (5, 6 and 7), a regaloside (11), a chalcone (12) and a fatty acid fraction (13). The structures of compounds were determined by NMR, IR, UV/VIS and mass spectroscopic studies. Compound 1 showed the highest COX-1 inhibition (94.1%) followed by 3, 8 and 12 with 38.7, 30.8 and 32.4%, respectively. Only compound 1 inhibited COX-2 enzyme by 36.9% at 80 ppm. In lipid peroxidation inhibitory assay, kaempferol showed 37 and 100 % inhibitions at 1 and 10 ppm, respectively. At 10 ppm, more than 20% inhibition was observed for compounds 4, 7, 10, 11 and 12 and 53% for compound 3. The compounds reported in here are isolated for the first time from Easter lily flowers including novel compounds 10, 11 and 12. Our results suggest that kaempferol and quercetin flavonoids contributed to the anecdotal medicinal properties of Easter lily flowers.     

桂火绳中化学成分的研究

从梧桐科火绳属桂火绳中提取分离到22个化合物,经结构鉴定为:羽扇豆醇(1),白桦脂酸(2),齐墩果酸(3),丁香脂素(4),(+)-异落叶松树脂醇(5),东莨菪内酯(6),对羟基肉桂酸(7),二十七碳酸单甘油酯(8),2-十八烯酸单甘油酯(9),sitoindosideⅡ(10),儿茶素(11),表儿茶素(12),表儿茶素3-O-β-D-吡喃木糖甙(13),山奈酚3-O-β-D-吡喃葡萄糖甙(14),5,7,4'-三羟基异黄酮(15),4'-O-methylgallocatechin(16),反式-二氢槲皮素-3-O-α-阿拉伯糖甙(17),顺式-二氢槲皮素-3-O-α-阿拉伯糖甙(18),反式-二氢槲皮素-3-O-β-吡喃葡萄糖甙(19),3,5,7,3',5'-五羟基-4'-甲氧基异黄酮(20),山奈酚-3-O-β-D-吡喃葡萄糖(6→1)-α-L-吡喃鼠李糖甙(21),以及槲皮素3-O-β-D-吡喃葡萄糖(6→1)-β-D-吡喃葡萄糖甙(22),这些化学成分首次从该属植物中分离出来。     

Cytotoxic and new tetralone derivatives from Berchemia floribunda (Wall.) Brongn

Two new alpha-tetralone (=3,4-dihydronaphthalen-1(2H)-one) derivatives, berchemiaside A and B (1 and 2, resp.), and one new flavonoid, quercetin-3-O-(2-acetyl-alpha-L-arabinofuranoside (3), together with ten known flavonoids compounds, eriodictyol (4), aromadendrin (5), trans-dihydroquercetin (6), cis-dihydroquercetin (7), kaempferol (8), kaempferol-3-O-alpha-L-arabinofuranoside (9), quercetin (10), quercetin-3-O-alpha-L-arabinofuranoside or avicularin (11), quercetin 3'-methyl ether, 3-O-alpha-L-arabinofuranoside (12), and maesopsin (13), were isolated from the bark of Berchemia floribunda. Their structures were determined by various NMR techniques and chemical studies. Compounds 3-13 were tested for their cytotoxic activity against human leukemia cells. Among them, kaempferol (8) and maesopsin (13) showed significant inhibitory activities against human leukemia cells CCRF-CEM and its multidrug-resistant sub-line, CEM/ADR5000, with IC(50) values of 14.0, 5.3, 10.2, and 12.3 microM, respectively.