FORMATION OF BRYONOLIC ACID IN CUCURBITACEOUS PLANTS AND THEIR CELL-CULTURES

Twenty-one species or varieties of cucurbitaceous plants belonging to nine genera, and their cell cultures, were investigated with respect to their capability of producing bryonolic acid, a pentacyclic triterpene having anti-allergic activity. Bryonolic acid was found in all but two species, being localized exclusively in the roots of mature plants or in the radicles of seedlings. Tracer experiments using watermelon seedlings have shown that the radicle is the sole site of bryonolic acid biosynthesis in the seedling. On the other hand, cultured cells derived from bryonolic acid-containing plants were capable of producing a substantial amount of bryonolic acid, irrespective of the original organs used for callus induction.