Dibenzofurans from the cultured lichen mycobionts of Lecanora cinereocarnea.

From the cultures of the spore-derived mycobionts of the lichen Lecanora cinereocarnea, five dibenzofurans, 3,7-dihydroxy-1,9-dimethyldibenzofuran, 2-chloro-3,7-dihydroxy-1,9-dimethyldibenzofuran, 2,8-dichloro-3,7-dihydroxy-1,9-dimethyldibenzofuran, 3-hydroxy-7-methoxy-1,9-dimethyldibenzofuran, and 2-chloro-7-hydroxy-3-methoxy-1,9-dimethyldibenzofuran, were isolated. Their structures were determined by spectroscopic methods.     

川芎内生菌Pseudeurotium ovale代谢产物研究

通过大孔树脂柱层析、凝胶柱层析和高效液相色谱等方法对川芎中分离得到的内生菌Pseudeurotium ovale的代谢物进行分离纯化,从中分离得到5个化合物,并通过核磁共振和质谱等波谱学技术手段确认所有化合物的结构,其中包含一个新的化合物4-methoxy-3-methyl-6-(1 E,3 E)-1,3-pentadien-1-yl-2 H-pyran-2-one(1)和四个首次从中分离得到的已知化合物:(2 E,4 E)-1-(2,6-dihydroxy-3,5-dimethylphenyl)-2,4-hexadien-1-one(2)、2-deoxy-sohirnone C(3)、trichodimerol(4)、3,7-dihydroxy-1,9-dimethyl-dibenzofuran(5)。体外抗炎活性测试表明化合物1可抑制经脂多糖(LPS)处理的RAW 264.7细胞中NO、IL-6和TNF-α等炎症因子的分泌。     

Xanthones from Swertia punctata

Isolation of 1-O-primeverosyl-3,8-dihydroxy-5-methoxyxanthone and 1-O-gentiobiosyl-3,7-dimethoxy-8-hydroxyxanthone, along with five known xanthones, isobellidifolin, methylbellidifolin, isoswertianin, methylswertianin and norswertianin-1-O-beta-D-glucoside, from the roots of Swertia punctata is reported. In the aerial parts four xanthones, bellidifolin, methylbellidifolin, swertianolin and mangiferin, and flavone-C-glucoside, isoorientin were identified. The chemotaxonomic and pharmacological significance of these results is discussed.     

C-methylated and C-prenylated isoflavonoids from root extract of Desmodium uncinatum

A pterocarpan, 1,9-dihydroxy-3-methoxy-2-methylpterocarpan (named uncinacarpan) and two isoflavanones, 5,7-dihydroxy-2',3',4'-trimethoxy-6-(3-methylbut-2-enyl)isoflavanone (named uncinanone D) and 5,4'-dihydroxy-7,2'-dimethoxy-6-methylisoflavanone (named uncinanone E), were isolated from the CH(2)Cl(2) root extract of Desmodium uncinatum (Jacq.) DC and characterised by spectroscopic methods. In addition, a rare pterocarpan edudiol and two known abietane diterpenes, 7-oxo-15-hydroxydehydroabietic acid and 7-hydroxycallitrisic acid were identified. The fraction of the root extract that was analysed induced germination of Striga hermonthica seeds, but none of the isolated compounds showed this activity.     

Phenolic constituents from Drypetes armoracia

The methanol extract of the dried stem bark of Drypetes armoracia Pax & Hoffm. afforded two compounds named drypearmoracein A, (E)-4,5,6,7-tetrahydroxy-2-benzylhept-2-enoic acid and drypearmoracein B, 2,3-dihydroxy-9,10-tetrahydroanthra-1,4-quinone along with five known compounds: friedelan-3 beta-ol, friedelin, friedelane-3,7-dione, drypemolundein B and beta-stigmasterol. Their structures were established on the basis of spectroscopic analysis and chemical evidence.     

Lack of altitudinal trends in phytochemical constituents of Swertia franchetiana (Gentianaceae)

Diverse biological characters commonly vary with altitude in species that have a wide altitudinal distribution, partly at least as a result of adaptation to differences in aridity, but whether such variation exists for phytochemical constituents remains unknown. Therefore, levels of seven important phytochemical constituents of Swertia franchetiana (swertiamarin, oleanolic acid, swertisin, mangiferin, 1,5,8-trihydroxy-3-methoxyxanthone, 1,8-dihydroxy-3,7-dimethoxyxanthone and 1,8-dihydroxy-3,5-dimethoxyxanthone) were studied and statistically compared, using materials collected from sites ranging from 2200 to 3960 m in altitude. Swertiamarin was the most abundant in all samples, then mangiferin, oleanolic acid and the other three xanthones. Throughout the distributional range of this species, no altitudinal trend was detected for other constituents except 1,8-dihydroxy-3,7-dimethoxyxanthone, which showed a negative correlation with altitude. However, the concentration of 1,8-dihydroxy-3,7-dimethoxyxanthone and mangiferin showed a significantly latitudinal and longitudinal correlation.     

Immunosuppressive constituents from Saussurea medusa.

The methanol extract of Saussurea medusa Maxim afforded two lignans: 2alpha-guaicyl-4-oxo-6alpha-catechyl-3,7-dioxabicyclo [3.3.0]octane and 1alpha-hydroxy-2alpha,4alpha-guaicyl-3,7-dioxabicyclo[3.3.0]octane; two chlorophyll derivatives: 13-epi-phaeophorbide-a and 13-epi-phaeophorbide-a methyl ester; one megastigmane derivative: 3beta-hydroxy-5alpha,6alpha-epoxy-7-megastigmen-9-one, along with 19 known compounds. Their structures were established on the basis of spectroscopic studies.     

Xanthones of Centaurium pulchellum

1-Hydroxy-3,7,8-trimethoxyxanthone, 1,8-dihydroxy-3,7-dimethoxyxanthone and 1,8-dihydroxy-3,5-dimethoxyxanthone have been isolated from the whole plant of Centaurium pulchellum; the compounds were characterized by UV and NMR spectroscopy.     

Sesquiterpene lactone glucosides and alkyl glycosides from the fruit of cumin

From the polar portion of the methanolic extract of cumin (fruit of Cuminum cyminum L.), two sesquiterpenoid glucosides, cuminoside A and B, and two alkyl glycosides were isolated together with five known compounds. Their structures were established as (1S,5S,6S,10S)-10-hydroxyguaia-3,7(11)-dien-12,6-olide beta-D-glucopyranoside, (1R,5R,6S,7S,9S,10R,11R)-1,9-dihydroxyeudesm-3-en-12,6-olide 9-O-beta-D-glucopyranoside, methyl beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside and ethane-1,2-diol 1-O-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside, respectively.     

The Chemical Constituents of Swertia przewalskii Pissjauk.

Seven xanthonenoid compounds and a triterpenic acid have been isolated from Swertia przewalskii Pissjauk. Their structures were identified as 1,8-dihydroxy-3,7-dimethoxyxarthone(Ⅰ), 1,7-dihydroxy-3,8-dimethoxyxanthone (Ⅱ), oleanolic acid (Ⅲ), l-hydroxy-3,7,8-trimethoxyxanthone (Ⅳ), 1,7,8-trihydroxy-3-methoxyxanthone (Ⅴ), 8-0-[β-D-xylopyranosyl-(l--6)-β-D-glucopyranosyl]- 1,7-dihydr0xy- 3-methoxyxanthone (Ⅵ), 1-O- [β-D-xylopyranosyl-(1-6)-β-D-glucopyranosyl]-7,8-dihydroxy- 3-methoxyxanthone (Ⅶ) and 1-O- [β-D-xylopyranosyl-(1-6)-β-D-glucopyranosyl]-8-hydroxy-3,7-dimethoxyanthone (Ⅷ) respectively, by means of chemical and spectral methods or comparing with the authentic samples directly.     

Flavonoids and coumarins from Platymiscium praecox

The wood of Platymiscium praecox Mart. (Leguminosae-Lotoideae) contains sitosterol, 4,2′,4′-trihydroxychalcone, (2R)-7-hydroxyflavanone, (±)-7,4′-dihydroxyflavanone, (2S, 3S)-3,7-dihydroxyflavanone, 3,7-dihydroxyflavone, 3,7,4′-trihydroxyflavone, 6,7-dihydroxy-4′-methoxyisoflavone and 6,7-dimethoxycoumarin. It also contains three novel compounds: 7-hydroxy-4-methoxy-5-methylcoumarin, 7-O-glucosyloxy-4-methoxy-5-methylcoumarin and 7-hydroxy-4,8-dimethoxy-5-methylcoumarin.     

Unusual naphthoquinones, catechin and triterpene from Byrsonima microphylla

The new triterpene Delta1-lupenone (1), together with lupeol, beta-amyrin and betulin were isolated from the wood of Byrsonima microphylla (Malpighiaceae). The new compounds 3-hydroxy-2-methoxy-8,8,10-trimethyl-8H-antracen-1,4,5-trione (2), 3,7-dihydroxy-2-methoxy-8,8,10-trimethyl-7,8-dihydro-6H-antracen-1,4,5-trione (3), (2S*,10aR*)-2,8-dihydroxy-6-methoxy-1,1,7-trimethyl-2,3,10, 10a-tetrahydro-1H-fenantren-9-one (4) and (2S,3S)-3'-hydroxy-4',5,7-trimethoxy-flavan-3-ol (5) were also isolated through monitored TLC using the antioxidant beta-carotene reagent. The antioxidant potential of the compounds 2-5 was measured and none of them showed activity. The structures of these compounds were elucidated by chemical and spectroscopic analysis based on NMR techniques (1H, 13C NMR, COSY, nOe difference, HMQC and HMBC), UV and MS.     

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.     

37-Dihydroxy-8-methoxyflavone from Zuccagnia punctata

A phytochemical examination of the leaves of Zuccagnia punctata resulted in the isolation and identification of 3,7-dihydroxyflavone and 3,7-dihydroxy-8-methoxyflavone. The latter is a new natural product.     

Xanthones from Frasera albomarginata and F. speciosa

Seven 1-hydroxyxanthones have been isolated from the roots of Frasera albomarginata. There were 1-hydroxy-3,7-dimethoxy-, 1-hydroxy-3,5-dimethoxy-, 1,8-dihydroxy-3,5-dimethoxy-, 1-hydroxy-2,3,4,7-tetramethoxy-, 1-hydroxy-2,3,4,5-tetramethoxy-, 1-hydroxy-3,4,7-trimethoxy- and 1-hydroxy-2,3,5-trimethoxyxanthone. Six 1-hydroxyxanthones were obtained from the roots of F. speciosa. These were 1-hydroxy-2,3,4,5-tetramethoxy-, 1-hydroxy-2,3,4,7-tetramethoxy-, 1-hydroxy-2,3,5-trimethoxy-, 1,7-dihydroxy-2,3,4-trimethoxy-, 1,7-dihydroxy-2,3-dimethoxy- and 1,3-dihydroxy-4,5-dimethoxyxanthone.     

Benzoquinone derivatives of Myrsine africana and Maesa lanceolata

The fruits of Myrsine africana afforded two new benzoquinone derivatives, methylvilangin and methylanhydrovilangin. On the other hand, from the fruits of Maesa lanceolata two more novel compounds; 2,5-dihydroxy-3-(nonadec-14-enyl)-benzoquinone and lanciaquinone were isolated. Their structural elucidation was achieved by spectroscopic measurements including 2D NMR experiments.     

Preparation and characterization of some keto-bile acid azines

New acyclic dimers of ketocholanic acids with hydrazine were obtained. Crystal structure was determined for the 3,7-dihydroxy-12-ketocholanic acid azine. Some distinctive (1)H NMR signals are assigned for the entire set of azines.     

Homoisoflavonoids from Caesalpinia sappan

Three new homoisoflavonoids, 7-hydroxy-3-(4′-hydroxybenzylidene)-chroman-4-one, 3,7-dihydroxy-3-(4′-hydroxybenzyl)-chroman-4-one and 3,4,7-trihydroxy-3-(4′-hydroxybenzyl)-chroman were isolated from the dried heartwood of Caesalpinia sappan, together with the known compounds 4,4′-dihydroxy-2′-methoxychalcone, 8-methoxybonducellin, quercetin, rhamnetin and ombuin.     

Study on the Chemical Constituents of Comastoma pulmonarium (Turcz.) Toyohuni

Eight compounds were isolated from Comastoma pulmonarium (Gentianaceae). Theirstructures are identified as1,8-dihydroxy-3,5-dimethoxyxanthone(Ⅰ),1,8-dihydroxy-3,7-dimetho-xyxanthone(Ⅱ), 1-hydroxy-3,7,8-trimethoxyxanthone(Ⅲ),8-hydroxy-l,3,5-trimethoxyxanthone(Ⅳ), 1,3,8-trihydroxy-7-methoxyxanthone(Ⅴ), 1-O-β-D-glucopyranosyl-3,8-dihydroxy-7-methxy-xanthone(Ⅵ), oleanolic acid(Ⅶ) and swertisin(Ⅷ) by means of chemical methods andUV, IR, NMR and MS respectively. The compound Ⅵ is a new natural product. It wasnamed as comastomaside.     

Flavonoids from shoots and roots of Trifolium repens (white clover) grown in presence or absence of the arbuscular mycorrhizal fungus Glomus intraradices

White clover (Trifolium repens) plants were grown in the presence or absence of the arbuscular mycorrhizal fungus Glomus intraradices. Flavones, 4',5,6,7,8-pentahydroxy-3-methoxyflavone and 5,6,7,8-tetrahydroxy-3-methoxyflavone, as well as two flavones 3,7-dihydroxy-4'-methoxyflavone and 5,6,7,8-tetrahydroxy-4'-methoxyflavone never previously reported in plants, were isolated. The known 3,5,6,7,8-pentahydroxy-4'-methoxyflavone, 2',3',4',5',6'-pentahydroxy-chalcone, 6-hydroxykaempferol, 4',5,6,7,8-pentahydroxyflavone and 3,4'-dimethoxykaempferol were also obtained. Analysis of extracts obtained from roots and shoots revealed that the compositions of the flavonoid mixtures varied with growing conditions. Quercetin, acacetin and rhamnetin accumulated in roots of inoculated plants, whereas they were not detected in non-inoculated plants.