抄録
In our previous publications, we have reported that extract of cocklebur containsan antibacterial substance. This substance was purified using silica gel column chromatography and TLC; it was dissolved in acetone and successively crystallized by adding hexane. The crystal appeared needle-like and white, with a melting point of 60℃ and molecular weight of 246. IR, UV and 1H-NMR spectra revealed that the compound was xanthatin. Minimum inhibitory concentrations (MICs) of xanthatin obtained were 12.5-100 μg/ml against Bacillus sp. which usually contaminates koji (qu) used in the preparation of alcoholic beverages. MICs of xanthatin were 25-100 μg/ml against Candida sp., Pichia sp., Saccharomycopsis sp. and Torulaspora sp.. Therefore, the inhibitory effect exhibited by xanthatin from cocklebur leaf extract against Bacillus sp. and some film-forming yeasts would be very useful to prevent contamination in koji and during production of alcoholic beverages.
