[Chemical Constituents from Przewalskia tangutica].

Objective: To study the Chemical constituents from Przewalskia tangutica. Methods: The compounds were isolated and identified from n-butanol extract of Przewalskia tangutica by various chromatographic and spectral techniques. Results: Twelve polar compounds were isolated and identified as scopolin( 1),fabiatrin( 2),rutin( 3),queroetin-3-O-rutinoside-7-O-ß-D-glucopyranoside( 4),protocatechuate( 5),vanillic acid( 6),thymine( 7),uracil( 8),cytosine( 9),adenine( 10),uridine( 11) and adenosine( 12). Conclusion: Compounds 3 ~ 5,8 ~ 12 are obtained from Przewalskia tangutica for the first time.

Bioactive halogenated dihydroisocoumarins produced by the endophytic fungus Lachnum palmae isolated from Przewalskia tangutica.

Guided by the UPLC-ESIMS profile, seven previously undescribed halogenated dihydroisocoumarins, palmaerones A-G, along with eleven known dihydroisocoumarins, were isolated from Lachnum palmae, an endophytic fungus from Przewalskia tangutica by exposure to a histone deacetylase inhibitor SAHA. Structures of the isolates were elucidated by analysis of their NMR, MS and optical rotation values. The antimicrobial, anti-inflammatory and cytotoxic activities of palmaerones A-G were evaluated. Palmaerones A-G showed antimicrobial activities against the strains (C. neoformans, Penicillium sp., C. albicans, B. subtilis and S. aureus), and palmaerone E exhibited potential antimicrobial activities against all the test strains with the MIC value in the range of 10-55 µg/mL. Palmaerones A and E exhibited moderate inhibitory effects on NO production in LPS-induced RAW 264.7 cells, with the IC50 values of 26.3 and 38.7 µM, respectively and no obvious toxicities were observed at 50 µM. Palmaerone E showed weak cytotoxicity against HepG2 with the IC50 value of 42.8 µM. This work provides an effective strategy for expanding natural product resource.

Cytotoxic triterpenoid saponins from Clematis tangutica.

Eight previously undescribed oleanane-type triterpenoid saponins, clematangoticosides A-H, together with eight known saponins, were isolated from the whole plants of Clematis tangutica (Maxim.) Korsh. Their structures were elucidated by extensive spectroscopic analysis, in combination with chemical methods (acid hydrolysis and mild alkaline hydrolysis). Clematangoticosides D-G were found to be unusual 23, 28-bidesmosidic glycosides. The cytotoxic activities of all of the isolated saponins were evaluated against the four human cancer cell lines SGC-7901, HepG2, HL-60 and U251MG. Clematoside S, sapindoside B, kalopanax saponin A, and koelreuteria saponin A exhibited cytotoxicity against all of the test cancer cell lines with IC50 values in the range of 1.88-27.20 µM, while clematangoticoside D and F showed selective cytotoxicity against SGC-7901 with IC50 values of 24.22 and 21.35 µM, respectively.