ISOLATION AND PREPARATION OF H-3 TETRANDRINE

Tetrandrine is a bisbenzytehahydroisoquinoline alkaloid. Its structure is very complex and the preparation of labeled derivatives is difficu lt. We have prepared H-3-tetrandrine using the tritium gas exposure me thod.(1) This method produces many fragments which make isolation and purification of small quantities difficult. We investigated these frag ments of unlabeled d-tetrandrine and found almost all contain one to s everal hydroxide groups. Using this information, we designed a two-ste p paper chromatography method for isolation and purification of H-3-Te trandrine. This method involves the application of a pH 4.7 Na2HPO4-ci tric acid buffer to the paper to block the migration of hydroxide grou p fragments of tetrandrine. H-3-tetrandrine was successfully with a ra diochemical purity of 90%.