Antimicrobial components in leaves of Lycium chinense Mill

Biologically active compounds in leaves of Lycium chinense (Lycii Folium) w ere examined to develop the effective use of this plant as a health food. T he methanol extract of Lycii Folium exhibited antimicrobial activities, and one of the active compounds was identified as lyciumoside I (1) which is a characteristic component of Lycium chinense. Furthermore, the methanol ext ract of Lycii Folium inhibited the growth of Helicobacter pylori. The activ e component against H. pylori was also identified as 1. Quantitative analys es revealed that 1 was extracted into Kuko tea in high concentration. The h ydrolysis products of 1 were also assayed for antimicrobial activity to stu dy their structure-activity relationship.