A pentacyclic quinone diosindigo B from the heartwood of Diospyros melanoxylon

Diosindigo A, diosindigo B and biramentacéone have been isolated from heartwood of Diospyros melanoxylon. A violet pigment isolated from the same source has been shown to be a new pentacyclic quinone. Sunlight causes diosindigo B to change to the pentacyclic quinone and biramentacéone. The intense peaks at m/e 389 and 388 in the mass spectrum of diosindigo B are doublets which arise by fragmentation of both M⁺ and M⁺ + 2.     

The structure of jujubosides A and B,the saponins isolated from the seeds of Zizyphus jujuba

Stepwise chemical and enzymatic hydrolyses of jujubosides A and B, the saponins of the seeds of Zizyphus jujuba, afforded prosapogenins I, II and III. The sequence and configuration of the sugar linkages in the saponins and the pro-sapogenins were determined from the PMR data and the application of Klyne's rule of molecular rotations and structures were assigned to jujubosides A and B.     

Dulcosides A and B,new diterpene glycosides from Stevia rebaudiana

New diterpene glycosides, dulcosides A and B were isolated from Stevia rebaudiana Bertoni and their structures were established as 19-O-β-glu     

Dianthramides A and B,two N-benzoylanthranilic acid derivatives from elicited tissues of Dianthus caryophyllus

Two new phenolic derivatives, dianthramide A and B, were isolated from Dianthus caryophyllus tissues elicited with mycelial extracts of Phytophthora parasitica. The purified substances were identified on the basis of their spectral data and were characterized as N-salicyl-4-methoxyanthranilic acid (dianthramide A) and N-salicyl-4-hydroxyanthranilic acid methyl ester (dianthramide B). Dianthramides A and B co-occur in carnation tissues with the known phytoalexin dianthalexin.     

Steroidal saponins from Dioscorea floribunda: Structures of floribundasaponins A and B

Two steroidal saponins, floribundasaponins A and B isolated from the yams of Dioscorea floribunda, have been characterized as pennogenin-3-O-β-d-glucopyranoside and pennogenin-3-O-α-l-rhamnopyranosyl(1→4)-β-d-glucopyranoside.     

Cryptadines A and B, novel C27N3-type pentacyclic alkaloids from Lycopodium cryptomerinum

Two novel C₂₇N₃-type Lycopodium alkaloids, cryptadines A (1) and B (2) consisting of two octahydroquinoline rings (C₁₁N) and a piperidine ring (C₅N), have been isolated from the club moss Lycopodium cryptomerinum, and their structures and relative stereochemistry were elucidated on the basis of spectroscopic data, chemical transformations, and computational methods. Cryptadines A (1) and B (2) exhibited an inhibitory activity against acetylcholinesterase.     

Applanoxidic acids A, B, C and D, biologically active tetracyclic triterpenes from Ganoderma applanatum

Four novel polyoxygenated lanostanoid triterpenes, named applanoxidic acids A, B, C, and D, have been isolated from an Indonesian tropical fungus, Ganoderma applanatum. Their structures were determined by spectrocopic and chemical methods. Biological activity as an anti-tumour promoter was observed for these components.     

A pregnane ester and its glycoside from Orthenthera viminea

A new pregnane ester named ornogenin and its diglycoside designated as ornine were isolated from the dried twigs of Orthenthera viminea. On the basis of chemical and spectroscopic evidence, their structures were established as 12,20-di-O-cinnamoyl-sarcostin and 12,20-di-O-cinnamoyl-sarcostin-3-O-α-L-oleandropyranosyl(1 → 4)-O-β-D-cymaropyranoside, respectively.     

Flavescin: A new 1-ketopolyhydroxypregnene from Marsdenia flavescens

A new polyhydroxy-1-ketosteroid, flavescin, was isolated from Marsdenia flavescens A. Cunn. Its structure was elucidated as 12-O-acetyl-3β,8β,12β,14β-20-pentahydroxy-Δ⁵- pregnene-1-one.     

A pregnane ester triglycoside from Sarcostemma brevistigma

A new pregnane ester glycoside, brevine, was isolated from the dried twigs of Sarcostemma brevistigma. Its chemical and spectroscopic properties were consistent with the structure 11-O-benzoyl-sarcogenin-3-O-α-L-diginopyranosyl (1 → 4)-O-α-L-diginopyranosyl(1 → 4)-O-α-L-diginopyranoside.     

A pregnane ester diglycoside from hemidesmus indicus

A new pregnane ester diglycoside named desinine has been isolated from the dried twigs of Hemidesmus indicus. On the basis of chemical and spectroscopic evidence, its structure has been established as drevogenin B-3-O-β-D-oleandropyranosyl-(1→4)-β-D-oleandropyranoside.     

Amorfrutin A and B,bibenzyl antimicrobial agents from Amorpha fruticosa

Bioassay directed fractionation of the waxy fractions derived from the fruit of Amorpha fruticosa resulted in the isolation of amorfrutin A and B, active new antimicrobial agents. Spectroscopic studies, chemical degradation and synthesis showed them to be new bibenzyl metabolites.     

Viscidic acid A and B,two ent-labdane derivatives from Chrysothamnus viscidiflorus

The chemical investigation of Chrysothamnus viscidiflorus afforded, in addition to known bisabolene derivatives, elemicin and p-hydroxyacetophenone, two new diterpene acids. Their structures were determined, by spectroscopic methods and some chemical transformations, as ent-labd-8(17),13E-dien-15-ol-18-oic acid (viscidic acid A) and ent-labd-8(17),13E-dien-15-acetoxy-18-oic acid (visidic acid B).     

A pregnane ester diglycoside from Sarcostemma brevistigma

A pregnane ester diglycoside, brevinine, has been isolated from the dried twigs of Sarcostemma brevistigma. Its chemical and spectroscopic data are consistent with the structure 11-O-benzoyl-sarcogenin-3-O-α-L-diginopyranosyl-(1 → 4)-α-L-diginopyranoside.     

A pregnane ester diglycoside from periploca calophylla

A new pregnane ester diglycoside of ornogenin named as plocinine was isolated from the dried twigs of Periploca calophylla. On the basis of chemical and spectroscopic evidences its structure was established as 12,20-di-O-cinnamoyl sarcostin-3-O-α-L-oleandropyranosyl (1 → 4)-O-α-L-oleandropyranoside.     

云南匙羮藤甙A和B的结构

从云南匙羹藤(Gymnema yunnaflense Tsiang)中分离得到2个新C_(21)甾体甙,命名为云南匙羹藤甙A(Ⅰ)和B(Ⅱ)(gymnemaroside A, B)。据化学反应和光谱数据,推定其结构分别为:本波甙元3-氧-β-D-葡萄糖吡喃基-(1→4)-3-氧-甲基-6-去氧-β-D阿洛糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃甙〔penupogenin 3-O-β-D-glucopyranosyl-(1→4)-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside〕和吉马甙元3-氧-β-D-葡萄糖吡喃基-(1→4)-3-氧-甲基-6-去氧-β-D-阿洛糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃基-(1→4)-β-D-加拿大麻糖吡喃甙〔symnemarsgenm 3-O-β-D-glucopyranosyl-(1→4)-3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→d)-β-D-cymaropyranoside〕。     

Naphthoquinones and triterpenes from some asian Diospyros species

Investigation of the stem bark, wood and/or fruit of nine Asian Diospyros spp. (Ebenaceae) has revealed a range of triterpenes and naphthoquinones     

Intracellular distribution and origin of pentacyclic triterpenes in Calendula officinalis leaves

In Calendula officinalis leaves the cyclization of squalene to β-amyrin and its further oxidation to oleanolic acid as well as the biosynthesis of all derivatives of oleanolic acid 3-glucoside and some derivatives of oleanolic acid 3-glucuronoside occur in the microsomal fraction. The final metabolites of oleanolic acid 3-glucoside series i.e. pentaglycosides, are translocated from this fraction, one to the cell wall and plasmalemma fraction and the other to the cytosol. The derivatives of oleanolic acid 3-glucoronoside are synthesized partially in other fractions and accumulate in the different membraneous structures of the cell.     

A pregnane ester glycoside from Periploca calophylla

A new pregnane ester genin, plocigenin, and a new pregnane ester diglycoside, plocin, have been isolated from the dried twigs of Periploca calophylla. The chemical and spectroscopic properties are consistent with the structures 12,20-di-O-benzoyl drevogenin-D and 12,20-di-O-benzoyl drevogenin-D-3-O-β-D-oleandropyranosyl (1 → 4)-O-β-oleandropyranoside, respectively.     

Tetracyclic triterpenes from Parthenium fruticosum

The shrub Parthenium fruticosum was shown to contain the three isomeric tetracyclic triterpenes fruticin A, fruticin B and the known incanilin. Fruticins A and B are new substances with lanostane and cycloartane skeletons, respectively. Their structures were determined by chemical and spectroscopic methods. The stereochemistry of fruticin B was established by X-ray diffraction analysis.