Three new xanthones from Swertia bimaculata and their anti-5α-reductase activity.

Three new xanthones (1-3), together with five known ones (4-8), were isolated from whole herb of Swertia bimaculata. Their structures were established on the basis of detailed spectroscopic analysis (1D- and 2D-NMR, HRESIMS, UV, and IR) and comparison with data reported in the literature. New isolates were evaluated for their anti-5α-reductase activity. The results revealed that all new compounds showed weak activity with reductase inhibitions of 40.5 ± 2.8, 38.6 ± 2.5, and 48.9 ± 3.0%, respectively.

[Study on solid phase extraction and spectrophotometric determination of palladium with MCI-GEL resin].

Based on the color reaction of 2-(2-quinolinylazo)-5-diethylaminoaniline (QADEAA) with palladium(II) and the solid phase extraction of its colored complex with MCI-GEL reversed phase cartridge, a new method for the determination of trace palladium was established. In the presence of 0.2-2.0 mol x L(-1) of hydrochloric acid solution and CTMAB medium, QADEAA reacts with palladium(II) to form a stable 2:1 complex. The colored complex can be enriched by MCI-GEL reversed phase cartridge, and the retained chelates was then eluted by acetone. The eluant was determined by spectrophotometry at 615 nm. Beer's law is obeyed in the range of 0.01-1.5 mg x L(-1). This method was applied to the determination of palladium with good results.

Two new phenylpropanoids from Swertia atroviolacea and their anti-5α-reductase activity.

Two new phenylpropanoids (1-2), together with two known lignans (3-4), were isolated from whole herb of Swertia atroviolacea. The structures of the new metabolites were established on the basis of detailed spectroscopic analysis. Compounds 1 and 2 were evaluated for their anti-5α-reductase activity. The results revealed that 1 and 2 showed weak activity with reductase inhibitions of 45.6 ± 2.8% and 38.4 ± 2.5%, respectively.