Abstract
The growth of L. fermenti 36 which requires thiamine for its growth was inhibited by deoxythiamine (DOB_1), deoxymethylthiamine (DOMB_1) and deoxyethylthiamine (DOEB_1), but not for the growth of L. arabinosus and L. casei which do not require thiamine. The inhibition of these compounds for L. fermenti was recovered competitively and specifically by thiamine and their inhibition index was 200-300 for DOB_1 and DOMB_1,about 500 for DOEB_1. These compounds had no thiamine activity. The order of decreasing antithiamine potency was : pyrithiamine > DOB_1≒DOMB_1 > DOEB_1 > thiamine sulfuric acid ester > oxythiamine.
