Homoisoflavonoids from Ophiopogon japonicus Ker-Gawler

From the ethyl acetate extract of the tuberous roots of Ophiopogon japonicus (Liliaceae) eight known and five new homoisoflavonoidal compounds were isolated. The new compounds are 5,7-dihydroxy-8-methoxy-6-methyl-3-(2'-hydroxy-4'-methoxybenzyl)chroman-4-one (1), 7-hydroxy-5,8-dimethoxy-6-methyl-3-(2'-hydroxy-4'-methoxybenzyl)chroman-4-one (2), 5,7-dihydroxy-6,8-dimethyl-3-(4'-hydroxy-3'-methoxybenzyl)chroman-4-one (3), 2,5,7-trihydroxy-6,8-dimethyl-3-(3',4'-methylenedioxybenzyl)chroman-4-one (4) and 2,5,7-trihydroxy-6,8-dimethyl-3-(4'-methoxybenzyl)chroman-4-one (5). Their structures have been elucidated by mass and NMR spectroscopy. Compounds 4 and 5 are the first isolated homoisoflavonoids with a hemiacetal function at position 2.     

Muscarinic receptor binding activity of polyoxygenated flavones from Melicope subunifoliolata

The bark extract of Melicope subunifoliolata (Stapf) T.G. Hartley showed competitive muscarinic receptor binding activity. Six polymethoxyflavones [melibentin (1); melisimplexin (3); 3,3',4',5,7-pentamethoxyflavone (4); meliternatin (5); 3,5,8-trimethoxy-3',4',6,7-bismethylenedioxyflavone (6); and isokanugin (7)] and one furanocoumarin [5-methoxy-8-geranyloxypsoralen (2)] were isolated from the bark extract. Compounds 2 and 6 were isolated for the first time from M. subunifoliolata. The methoxyflavones (compounds 1, 3, 4, 5, 6, and 7) show moderate inhibition in a muscarinic receptor binding assay, while the furanocoumarin (compound 2) is inactive. The potency of the methoxyflavones to inhibit [(3)H]NMS-muscarinic receptor binding is influenced by the position and number of methoxy substitution. The results suggest these compounds are probably muscarinic modulators, agonists or partial agonists/antagonists.     

Flavonol and iridoid glycosides of Ajuga remota aerial parts

Six flavonol glycosides characterised as myricetin 3-O-alpha-rhamnosyl-(1'-->2')-alpha-rhamnoside-3'-O-alpha-rhamnoside, 5'-O-methylmyricetin 3-O-[alpha-rhamnosyl (1'-->2')][alpha-rhamnosyl (1'-->4')]-beta -glucoside-3'-O-beta-glucoside, 5'-O-methylmyricetin 3-O-alpha-rhamnosyl (1'-->2')-alpha-rhamnoside 3'-O-beta-galactoside, kaemferol 3-O-rutinoside-7-O-rutinoside, myricetin 3-O-rutinoside-3'-O-alpha-rhamnoside, myricetin 3-O-beta-glucosyl (1'-->2')-beta-glucoside-4'-O-beta-glucoside together with two iridoid glycosides identified as 6,8-diacetylharpagide and 6,8-diacetylharpagide-1-O-beta-(3',4'-di-O-acetylglucoside) have been isolated from extract of Ajuga remota aerial parts. Also isolated from the same extract were known compounds; kaempferol 3-O-alpha-rhamnoside, quercetin 3-O-beta-glucoside, quercetin 3-O-rutinoside, 8-acetylharpagide, ajugarin I and ajugarin II.     

Geranylated flavanones from the secretion on the surface of the immature fruits of Paulownia tomentosa

Chemical investigation of the methanol extract of the viscous secretion on the surface of immature fruits of Paulownia tomentosa furnished nine geranylated flavanones, 6-geranyl-5,7-dihydroxy-3',4'-dimethoxyflavanone (1), 6-geranyl-3',5,7-trihydroxy-4'-methoxyflavanone (2), 6-geranyl-4',5,7-trihydroxy-3',5'-dimethoxyflavanone (3), 6-geranyl-4',5,5',7-tetrahydroxy-3'-methoxyflavanone (4), 6-geranyl-3,3',5,7-tetrahydroxy-4'-methoxyflavanone (5), 4',5,5',7-tetrahydroxy-6-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]-3'-methoxyflavanone (6), 3,3',4',5,7-pentahydroxy-6-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]flavanone (7), 3,3',4',5,7-pentahydroxy-6-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]flavanone (8), and 3,4',5,5',7-pentahydroxy-3'-methoxy-6-(3-methyl-2-butenyl)flavanone (9), along with six known geranylated flavanones. Among these, compounds 4, 6-9 and the known 6-geranyl-3',4',5,7-tetraahydroxyflavanone (diplacone), 6-geranyl-3,3',4',5,7-pentahydroxyflavanone (diplacol) and 3',4',5,7-pentahydroxy-6-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]flavanone showed potent radical scavenging effects towards DPPH radicals.     

Non-alkaloid Constituents of Buxus sinica (Buxaceae)

From the aerial parts of Buxus sinica, ten non- alkaloid compounds were isolated and identified as cleomiscosin A ( 1 ), 3, 5-dihydroxyl-4', 6, 7-trimethyl flavone-3′- O-β- D-glucopyranoside ( 2 ), 3, 5, 3', 4′tetrahydroxyl-3, 6, 7-trimethyl flavone (3 ) , cleomiscosin A-4′- O-β- D-gluco-pyranoside (4 ), 3, 5-dimethoxybenzoicacid-4- O-β- D-glucopyranoside (5 ), 4′, 5-dihydroxyl-3, 6, 7-trimethyl flavone (6), lupine (7), ( + )-pinoresinol- O-β- D-glucopyranoside (8 ), β-sitosterol (9), and daucosterol (10). Their structures were identified by spectral evidence.     

Spasmolytic flavonoids from Syzygium samarangense (Blume) Merr. & L.M. Perry

The hexane extract of Syzygium samarangense (Ss.Hex) dose-dependently (10-1000 microg/ ml) relaxed the spontaneously contracting isolated rabbit jejunum. Four rare C-methylated flavonoids with a chalcone and a flavanone skeleton were isolated from Ss.Hex and were subsequently tested for spasmolytic activity. All flavonoids, identified as 2'-hydroxy-4',6'-dimethoxy-3'-methylchalcone (1), 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (2), 2',4'-dihydroxy-6'-methoxy-3'-methylchalcone (3), and 7-hydroxy-5-methoxy-6,8-dimethyl-flavanone (4), showed dose-dependent spasmolytic activity in the rabbit jejunum with IC50 values of 148.3 +/- 69.4, 77.2 +/- 43.5, 142.4 +/- 58.6 and 178.5 +/- 37.5 microg/ml (mean +/- SEM), respectively. The dihydrochalcone derivative of compound 1, 2'-hydroxy-4',6'-dimethoxy-3'-methyldihydrochalcone (5), when tested for spasmolytic activity, did not significantly relax the smooth muscle relative to the other compounds. Verapamil, a standard spasmolytic, has an IC50 value of 0.16 +/- 0.04 microg/ml. This is the first report of the relaxant activity of chalcones, specifically of compounds 1-3.     

Geranyl chalcone derivatives with antifungal and radical scavenging properties from the leaves of Artocarpus nobilis

Antifungal activity guided fractionation of the n-butanol extract from the methanol extract of the leaves of Artocarpus nobilis furnished 2',4',4-trihydroxy-3'-geranylchalcone (1), 2 ',4',4-trihydroxy-3'-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]chalcone (2), 2',4',4-trihydroxy-3'-[2-hydroxy-7-methyl-3-methylene-6-octaenyl]chalcone (3), 2',3,4,4'-tetrahydroxy-3'-geranylchalcone (4), 2',3,4,4'-tetrahydroxy-3'-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]chalcone (5). The chalcones 3 and 5 are new natural products whereas 1 and 2 are reported first time from the family Moraceae. All these compounds showed good fungicidal activity against Cladosporium cladosporioides and high radical scavenging activity towards the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical in TLC bio-autography method.     

Prolyl endopeptidase inhibitors from Syzygium samarangense (Blume) Merr. & L. M. Perry

Compounds isolated from the hexane extract of the leaves of Syzygium samarangense (Blume) Merr. & L. M. Perry were tested for inhibitory activity against the following serine proteases: trypsin, thrombin and prolyl endopeptidase. The compounds were identified as an intractable mixture of alpha-carotene and beta-carotene (1), lupeol (2), betulin (3), epi-betulinic acid (4), 2',4'-dihydroxy-6'-methoxy-3'-methylchalcone (5), 2'-hydroxy-4',6'-dimethoxy-3'-methylchalcone (6), 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (7), 2',4'-dihydroxy-6'-methoxy-3'-methyldihydrochalcone (8) and 7-hydroxy-5-methoxy-6,8-dimethylflavanone (9). Hydrogenation of compounds 5, 6 and 7 yielded compound 8, 2'-hydroxy-4',6'-dimethoxy-3'-methyldihydrochalcone (10) and 2',4'-dihydroxy-6'-methoxy-3',5'-dimethyldihydrochalcone (11), respectively. The hydrogenated products of compounds 6 and 7 were also tested for enzyme inhibitory activity. In addition, beta-sitosterol (12) and beta-D-sitosterylglucoside (13) were also isolated. This is the first report of the isolation of compounds 1-6, 8 and 13 from this plant. Compounds 3-8 and 10 exhibited significant and selective inhibition against prolyl endopeptidase among three serine proteases. This is the first report of this kind of activity for all these compounds.     

Antimicrobial and radical scavenging flavonoids from the stem wood of Erythrina latissima

From the stem wood of Erythrina latissima, two isoflavones and a flavanone were isolated and characterized as 7,3'-dihydroxy-4'-methoxy-5'-(gamma,gamma-dimethylallyl)isoflavone (erylatissin A), 7,3'-dihydroxy-6',6'-dimethyl-4',5'-dehydropyrano [2',3': 4',5']isoflavone (erylatissin B), (-)-7,3'-dihydroxy-4'-methoxy-5'-(gamma,gamma-dimethylallyl)flavanone (erylatissin C), respectively, in addition to 10 known flavonoids. Structures of these compounds were determined on the basis of their spectroscopic data. These compounds showed antimicrobial activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Candida mycoderma. The isolated compounds also exhibited weak radical scavenging properties towards DPPH radical.     

An anthraquinone and three naphthopyrone derivatives from Cassia pudibunda.

Chemical examination of the methanolic extract of the roots of Cassia pudibunda led to isolation of the new rubrofusarin-6-O-beta-D-glucopyranoside, quinquangulin-6-O-beta- D-apiofuranosyl-(1----6)-O-beta-D-glucopyranoside, quinquangulin-6-O-beta-D-glucopyranoside and chrysophanol dimethyl ether. Moreover the known chrysophanol, physcion, cis-3,3',5,5'-tetrahydroxy-4-methoxystilbene, trans-3,3',5,5' -tetrahydroxy-4-methoxystilbene, and cassiaside B were identified. The antimicrobial activity of some of these compounds is also reported.     

Chromenes from Peperomia serpens (Sw.) Loudon (Piperaceae)

Chromatographic separation of the CH2Cl2 extract from leaves of Peperomia serpens yielded two chromenes [5-hydroxy-8-(3',7'-dimethylocta-2',6'-dienyl)-2,2,7-trimethyl-2H-1-chromene (1) and 5-hydroxy-8-(3'-methyl-2'-butenyl)-2,2,7-trimethyl-2H-1-chromene-6-carboxylic acid (2)], besides the known chromene [methyl 5-hydroxy-2,2,7-trimethyl-2H-1-chromene-6-carboxylate (3)] and the flavonoid, dihydrooroxylin (4). Their structural elucidation were achieved by spectroscopic analyses. The antifungal activities of the CH2Cl2 extract and the isolated chromenes were measured bioautographically against Cladosporium cladosporioides and C. sphaerospermum, when it was found that the crude extract showed higher activity as compared to the pure compounds.     

New erythroxane-type diterpenoids from Fagonia boveana (Hadidi) Hadidi & Graf

The aerial parts of Fagonia boveana afforded two new erythroxane-type diterpenes, 3beta,15,16-trihydroxy-erythrox-4(18)-ene (2) and 15,16-dihydroxy-cis-ent-erythrox-3-ene (fagonene) (3) together with two known ones; 16-O-acetylfagonone (1) and 7beta-hydroxy fagonene (8). Also a new guaiane sesquiterpene alcohol, 6,10-epoxy-4alpha-hydroxy guaiane type sesquiterpene (4) has been isolated. In addition three 8-methoxy flavonols, 8-methoxy-quercetin-3,7,3'-trimethyl ether (ternatin) (5), gossypetin, 3,8,3',4' tetramethyl ether (6) and herbacetin-3,8-dimethyl ether (7) were also isolated. The structures of the isolated compounds have been determined on the basis of spectroscopic evidences as well as physical and chemical correlation with known compounds. On performing different assays for biological activities, 6 displayed significant cytotoxic activity against KA3IT and NIH3T3 cell lines, 8 was the most active antiviral against Herpes simplex type 1 while 7 was the most active cancer-preventive agent using protein-tyrosine kinase inhibitory method.     

Homoisoflavanones from Disporopsis aspera

From cytotoxic extracts of the roots of Disporopsis aspera Engl. (Liliaceae) a homoisoflavanone, disporopsin (3-(2',4'-dihydroxy-benzyl)-5,7-dihydroxy-chroman-4-one) (1) and three rare methyl-homoisoflavanones, 3-(4'-hydroxy-benzyl)-5,7-dihydroxy-6-methyl-chroman-4-one (2), 3-(4'-hydroxy-benzyl)-5,7-dihydroxy-6,8-dimethyl-chroman-4-one (3) and 3-(4'-hydroxy-benzyl)-5,7-dihydroxy-6-methyl-8-methoxy-chroman-4- one (4) along with five other known compounds, N-trans-feruloyl tyramine (5), adenine (6), 5-(hydroxymethyl)-2-furfural (7), beta-sitosterol (8) and beta-sitosteryl glucopyranoside (9) were isolated. The structures of compounds 1-2 were elucidated by spectral data (1, 2-D NMR and EIMS). The four homoisoflavanones (1-4) were found to be cytotoxic against a series of human cancer cell lines (HCT15, T24S, MCF7, Bowes, A549 and K562) with IC(50) ranging from 15 to 200 microM. Possible biosynthesis routes for homoisoflavonoids (1-4) are discussed.     

Isoflavonoids from roots of Erythrina zeyheri

Five isoflavonoids, (+/-)-7,2',4'-trihydroxy-8,3'-di(gamma,gamma-dimethylallyl)isoflavanone, (3R)-7,4'-dihydroxy-2'-methoxy-6,8-di(gamma,gamma-dimethylallyl)isoflavanone, (3R)-7,2',4'-trihydroxy-6,8-di(gamma,gamma-dimethylallyl)isoflavan, 2',4'-dihydroxy-8-gamma,gamma-dimethylallyl-2",2"-dimethylpyrano-[5,6:6,7]isoflavan and (6aS, 11aS)-3,6a-dihydroxy-9-methoxy-4,10-di(gamma,gamma-dimethylallyl)pterocarpan, along with five known compounds, were isolated from the roots of Erythrina zeyheri. Their structures were established on the basis of spectroscopic evidence, and their antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA) were estimated by determining minimum inhibitory concentrations.     

腺梗豨莶的新双色满

作者从腺梗莶的乙醚抽出物中分到一个新的双色满成分 ,基于光谱分析和应用二维核磁共振技术 ,它的化学结构已被确定为 3,3’ 双 (3,4 二氢化 6 甲氧基 2H 1 苯并吡喃 )或 3,3’ 双 (6 甲氧基色满 )。     

麻疯树皮的化学成分研究

从麻疯树(Jatrophac curcus L.)的树皮中分离得到12个化合物,经理化常数和波谱鉴定(IR,1H NMR,13C NMR,EI-MS)分别为二十六酸甲酯(1),β-谷甾醇(2),蒲公英萜醇(3),蒲公英甾醇(4),伪蒲公英甾醇(5),curcusones A(6),curcusones B(7),jatropholone A(8),jatropholone B(9),3,3′,4-三甲氧基鞣花酸(10),胡萝卜甙(11),蔗糖(12)。其中化合物1,4,5,10,12为首次从该植物中分离得到。     

Antioxidant and insect growth regulatory activities of stilbenes and extracts from Yucca periculosa

The methanol extract from the bark of Yucca periculosa F. Baker afforded 4,4'-dihydroxstilbene, resveratrol and 3,3',5,5'-tetrahydroxy-4-methoxystilbene and had growth regulatory activity against the Fall Army worm (Spodoptera frugiperda J.E. Smith, Lepidoptera:Noctuidae) an insect pest of corn. The most active compound was 3,3',5,5'-tetrahydroxy-4-methoxystilbene which had significant effects at 3 microg/g in diets. In addition to the inhibitory activity on bleaching of crocin induced by alkoxyl radicals, these compounds also demonstrated scavenging properties toward 2,2-diphenyl-1-picrylhydrazyl in TLC autographic and spectrophotometric assays. Our results indicate that these compounds could be involved in interference of sclerotization and moulting. These compounds appear to have selective effects on the pre-emergence metabolism of the insect. The results were fully comparable to known natural insect growth inhibitors such as gedunin and Cedrela extracts and have had a possible role as natural insecticidal agents.     

Glycosides of tricetin methyl ethers as chemosystematic markers in Stachys subgenus Betonica

Nine species from the genus Stachys L. representing subgenera Stachys and Betonica were surveyed for flavonoid glycosides by means of HPLC coupled to diode-array detection and LC-APCI-MS. Those species belonging to subgenus Betonica were characterised by the presence of glycosides of tricetin methyl ethers, including a new derivative, which was isolated from S. scardica Griseb. and identified as tricetin 3',4',5' -trimethyl ether 7-O-beta-glucopyranoside by spectroscopic methods. This type of flavonoid was absent from species belonging to subgenus Stachys and can be considered as a chemosystematic marker for subgenus Betonica.     

Antioxidant lignans from Larrea tridentata

Three lignans, (7S,8S,7'S,8'S)-3,3',4'-trihydroxy-4-methoxy-7,7'-epoxylignan, meso-(rel 7S,8S,7'R,8'R)-3,4,3',4'-tetrahydroxy-7,7'-epoxylignan, and (E)-4,4'-dihydroxy-7,7'-dioxolign-8(8')-ene, together with 10 known compounds, were isolated from the leaves of Larrea tridentata. The structures of the new compounds were determined primarily from 1D and 2D NMR spectroscopic analysis. Their antioxidant activities against intracellular reactive oxygen species were evaluated in HL-60 cells.     

Myricetin and quercetin methyl ethers from Haplopappus integerrimus var. Punctatus

Nine flavonoids including two new myricetin derivatives, myricetin 3′,4′-dimethyl ether and myricetin 3,3′, 4′-trimethyl ether, were obtained from Haplopappus integerrimus var. punctatus. The known compounds are quercetin 7,3′-dimethyl ether, querectin 3,3′-dimethyl ether, isorhamnetin, quercetin 3,7-dimethyl ether, quercetin 3-methyl ether, quercetin and quercetin 3-β-d-glucoside.