[Studies on the chemical constituents of Urtica dioica L. grown in Tibet Autonomous Region].

Studies on the whole herb of Urtica dioica L. grown in Nyingchi area, China's Tibet Autonomous Region, resulted in the isolated of nine compounds: beta-sitosterol, trans-ferulic acid, dotriacotane, erucic acid, ursolic acid, scopoletin, rutin, quercetin and p-hydroxylbenzalcohol. Dotriacotane, erucic acid, scopoletin, rutin and p-hydroxylbenzalcohol were obtained from Urtica L.

Secondary metabolites from fungus Fomes cajanderi.

As a part of our systematic investigation of chemical constituents of Polyporaceous family fungi (Basidiomycetes), we studied the fungus of Fomes cajanderi P. Karst collected from Jiling province, China in 1997, and isolated 15 compounds, of which, compound 5 is a naturally occurring new metabolite, while 9, 11 and 12 are new derivatives. Their structures were identified by means of MS, NMR spectra and X-ray crystallographic analysis.

[Chemical study on bioactive natural products of novel structural types].

Bioactive natural products of novel structural types play a highly significant role in the drug discovery and development process. Of the 1,031 new chemical entities covering all diseases in the years 1981-2002, 48% were natural product mimics, 5% were the direct utility of natural products as sources of novel structures. Up to now, the main challenges are more efficient and rapid processes for discovery and isolation of bioactive natural products of novel structural types.

[Synthesis and anti-inflammatory analgesic activities of sinomenine derivatives].

Aim: To provide basic data for the synthesis of new sinomenine derivatives.

Methods: The C ring in sinomenine was modified.

Results: Seven compounds were prepared and screened for anti-inflammatory and analgesic activities.

Jenamidines A to C: unusual alkaloids from Streptomyces sp. with specific antiproliferative properties obtained by chemical screening.

Three new naturally occurring bicyclic alkaloids, jenamidines A (1), B (2) and C (3), were discovered and isolated from the culture broth of Streptomyces sp. (strain HKI0297) via the chemical screening approach. Fermentation, isolation, structure and biological activities of these three new secondary metabolites are reported.

New 2-o-methylrhamno-isoflavones from Streptomyces sp.

Chemical screening with extracts of Actinomycetes strains resulted in the detection, isolation and structure elucidation of five new isoflavone glycosides from Streptomyces sp. (GT 51173): 5-O-alpha-L-rhamnopyranosyl genestein (genestein G1, 1), 5-O-alpha-L-rhamnopyranosyl-7-O-[2-O-(methyl)-alpha-L-rhamnopyranosyl] genestein (genestein G2, 2), 7,4'-O-di-[2-O-(methyl)-alpha-L-rhamnopyranosyl] daidzein (daidzein G1, 3), 6-O-methyl-7-O-[2-O-(methyl)-alpha-L-rhamnopyranosyl] daidzein (daidzein G2, 4) and 7-O-[2-O-(methyl)-alpha-L-rhamnopyranosyl] daidzein (daidzein G3, 5). As a striking structural feature, 2-5 bear one or two alpha-L-rhamnopyranosyl sugar moieties with methoxy groups in an axial position at C-2.

Fomlactones A-C, novel triterpene sactones from Fomes cajanderi.

Investigation of the neutral ether extracts of the fungus Fomes cajanderi led to the isolation of three novel ketal lactones named fomlactones A (1), B (2), and C (3). These compounds were identified by analysis of IR, HRMS, CD, and 1D and 2D NMR data. The structure of fomlactone C (3) was confirmed by X-ray diffraction analysis.