Hepatoprotective studies on methanolic extract of caryopses of Echinochloa colona Link.

The caryopses (seeds) of Echinochloa colona Link of family Poaceae are traditionally used for the treatment of jaundice. The methanolic extract of caryopses of Echinochloa colona (ECME) was evaluated for its hepatoprotective activity in paracetamol (3g/kg per oral) and ethanol (5g/kg per oral) intoxicated rats while its antihepatotoxic activity against D-galactosamine (400mg/kg body weight intra peritoneal). The activity of the extract was assessed on the basis of improvement in the altered level of various serum biochemical parameters and in the changes occurred in the histology of liver of the rats. The extract was also investigated for its antioxidant potential by employing different in vitro methods. The extract exhibited ferrous ion reducing power, 1,1 Diphenyl-1-picryl hydrazyl (DPPH), superoxide, nitric oxide and hydroxyl radical scavenging activities. The significant (p<0.001) hepatoprotective and antioxidant activities exhibited by the extract ECME, in different in vivo models and in vitro studies respectively may be attributed to the flavonoids and phenolic compounds present in the extract.

Two Novel Spirostene Glycosides from Selaginella chrysocaulos and their Chemotaxonomic Significance.

During an investigation of the Indian heterosporous fern Selaginella chrysocaulos, two novel C28 spirostene monosides, chrysocauloside A and B were identified. Chrysocauloside A (1ß,3ß-dihydroxy-20S,22R-spirost-5-ene-1-yl ß-D-glucopyranoside) and chrysocauloside B (1ß,3ß-dihydroxy-20S,22R-spirost-5-ene-1-yl ß-D-galactopyranoside) are O-glycosylated at C-1 and each bear a methyl group at C-24 and C-25. Spectroscopic (NMR) and MS data for the new compounds are given and the taxonomic significance of the occurrence of spirostenes in the group of Lycophyta is discussed.

Cycloartanes from the gum resin of Gardenia gummifera L.f.

The gum resin exuding from the leaf buds of Gardenia gummifera was investigated. Eight new cycloartane triterpenes, 1-6, 8, and 10, together with two known triterpenes, 25-hydroxycycloart-23-en-3-one (7) and cycloartenone (9), were isolated and identified by extensive NMR spectroscopy. For cycloartenone (9), full NMR assignments are given as these data were not available in the literature. Eight compounds possess a C(3)=O group, two are 3,4-secocycloartanes bearing a free C(3)OOH group; in one of the cycloartanes, gummiferartane-9 (10), ring A occurs as a seven-membered lactone.

Minor pregnanes from Caralluma adscendens var. gracilis and Caralluma pauciflora.

Phytochemical investigation of Caralluma adscendens var. gracilis and Caralluma pauciflora (Asclepiadaceae) whole plant extracts allowed to isolate one pregnane glycoside and two pregnanes characterized as 12ß,20-O-dibenzoyl-5α,6-dihydrosarcostin ß-oleandropyranosyl-(1→4)-ß-cymaropyranosyl-(1→4)-ß-digitoxypyranosyl-(1→4)-ß-cymaropyranosyl-(1→4)-ß-cymaropyranoside (1), 12ß-O-benzoyl-3ß,11α,14ß,20R-pentahydroxy-pregn-5-ene (2), and 11α-O-benzoyl-3ß,12ß,14ß,20R-pentahydroxy-pregn-5-ene (3), respectively. Their structural characterization was obtained on the basis of extensive NMR spectral studies. Three known pregnane glycosides along with lupeol and ß-sitosterol were also isolated and characterized.

Cycloartane triterpenes from dikamali, the gum resin of Gardenia gummifera and Gardenia lucida.

We report on the chemical investigation of dikamali gum, which is the resin of Gardenia gummifera and G. lucida (Rubiaceae). Six new cycloartane triterpenes, dikamaliartanes A-F (1-6, resp.), together with a known flavonoid (7), were isolated and identified by NMR spectroscopy. All six cycloartanes are characterized by an open A-ring with a free COOH group at C(3). In four of them, the C-atoms C(23)-C(27) form a 4-methylfuran-2-yl moiety. Bacterial assays using Staphylococcus aureus, Candida albicans, and Mycobacteria have been carried out but did not reveal significant activity.

Pregnane glycosides from Caralluma adscendens var. fimbriata.

Eleven novel pregnane glycosides, 2-7 and 9-13, of which four, i.e., 10-13, comprised a new pregnane-type genin exhibiting a hydroxymethylene instead of a Me group at C(19), and the known pregnane glycoside stalagmoside V (8) were isolated from whole plants of Caralluma adscendens var. fimbriata, a native Indian succulent plant. Their structures were elucidated by extensive 2D-NMR spectroscopic studies.

Structurally unique biflavonoids from Selaginella chrysocaulos and Selaginella bryopteris.

Chemical investigation of Selaginella chrysocaulos from Northeast India yielded three new (i.e., 1-3) and two known biflavonoids. From Selaginella bryopteris, collected in the southern part of India, one new (11) and eleven known biflavonoids of the amentoflavone- and hinokiflavone-type were isolated and identified. The structures of the compounds were elucidated by 1D- and 2D-NMR spectroscopy, and by mass spectrometry. The absolute configurations of chiral biflavonoids with flavanone subunits (from S. bryopteris) were determined with the aid of circular-dichroism (CD) spectroscopy. Several very rare or even unprecedented substructures in biflavonoids were found.