Strictosidine is a key intermediate in the biosynthesis of the terpenoid indole alkaloid (TIA) pathway. It results from a condensation reaction, catalyzed by strictosidine synthase (STR), between tryptamine and secologanin. We have now developed a useful method, based on enzyme-assisted synthesis, to produce strictosidine. Our procedure utilizes leaf extracts from Japanese honeysuckle Lonicera japonica Thunb. as a secologanin source. In these experiments, an enzyme extract was prepared from transgenic yeast Saccharomyces cerevisiae that expresses the Catharanthus roseus STR (CrSTR) coding region. Strictosidine was then isolated with a 38% yield based on the initial amount of tryptamine in the enzymatic reaction.