OBJECTIVETo analyze chlorogenic acids contained in Lonicera japonica water extracts, and to investigate the regularity of changes in chlorogenic acids during the water extraction process.

METHODAgilent Zorbax SB-C18 analytical column (4.6 mm x 250 mm, 5 microm) was eluted with 0.1% formic acid (A)-acetonitrile (B) as the mobile phase at a flow rate of 0.5 mL x min(-1). The detection wavelength was 327 nm and the column temperature was 30 degrees C. Negative MS(n) mode was adopted in mass spectrum for ananlyzing the 22 samples of L. japonica water extracts.

RESULTCaffeic acid and six organic acids were accurately identified from the water extracts. During the extraction, the contents of chlorogenic acid and 3,5-dicaffeoylquinic acid became stable or gradually decreased after reaching the highest value. The contents of other components had long been increasing, but with a decreasing rate of change.

CONCLUSIONThis study provides basis for improving the production process of traditional Chinese medicine preparations containing L. japonica.