OBJECTIVETo study the chemical constituents of the dried rhizome of Ardisia gigantifolia.

METHODThe 60% ethanol extract was extracted with EtOAc, and then separated and purified by column chromatography using silica gel and preparative HPLC. Their structures were identified on the basis of spectral analysis and physico-chemical properties.

RESULTNine compounds were isolated and identified as 11-O-galloylbergenin (1), 11-O-syringylbergenin (2), 11-O-protocatechuoylbergenin (3), 4-O-galloylbergenin (4), 11 -O-vanilloylbergenin (5), (-) -epicatechin-3-gallate (6), stigmasterol-3-O-beta-D-glucopyranoside (7), (-) -4'-hydroxy-3-methoxyphenyl-beta-D-[6-O-(4"-hydroxy-3", 5"-dimethoxybenzoyl)] -glucopyranoside (8), and beta-sitosterol (9).

CONCLUSIONCompounds 3, 4 and 7 were isolsted from the genus Ardisia for the first time, while compounds 1, 2, 5 and 6 were isolated from this plant for the first time.

Ardisia ; chemistry ; Rhizome ; chemistry

Based on Ag nanoparticles as the surface-enhanced Raman spectroscopy (SERS)-active nanostructure, the SERS of uric acid was presented in the paper. The absorption spectroscopies of uric acid and the mixture of silver colloids and uric acid were measured. The possible enhancing mechanism of the uric acid on silver colloid was speculated. The characteristic SERS bands of uric acid were tentatively assigned. The influence of absorption time and different ion on the SERS of uric acid were also discussed. The SERS spectral intensity changes linearly with the uric acid concentration, which indicated that the SERS might provide a new kind of direct and fast detecting method for the detection of uric acid. The detection limit of uric acid in silver sol is found to be 1 mg/L.
Metal Nanoparticles ; chemistry ; Silver ; chemistry ; Spectrum Analysis, Raman ; methods ; Surface Properties ; Uric Acid ; analysis