Abstract
It was confirmed by bioautography that S-benzoyl derivatives of thiamine namely BTMP, SBT and DBT were de-S-benzoylated to change into TMP, thiamine and OBT, respectively, by L-cysteine in MaciasR's medium. BTMP and SBT have effect as much as thiamine on Lactobacillus fermenti 36 in this medium, but if there is no L-cysteine in the medium, these compounds have little thiamine activity. DBT does not affect as thiamine on this organism. BTMP, SBT, DBT and OBT have thiamine activity by autoclaving, even if there is no L-cysteine in the medium.
