Antineoplastic agents, 294. Variations in the formation of pancratistatin and related isocarbostyrils in hymenocallis littoralis

By cloning Hymenocallis littoralis, a practical biosynthetic procedure was developed for producing pancratistatin [1], The plant tissue culture→greenhouse→field production sequence was successively utilized for increasing an original 1.5 kg of wild H. littoralis bulbs to some 60,000 bulbs at present. In the central Arizona Sonoran Desert, the tropical H. littoralis was found to reach a maximum pancratistatin content in October and a minimum in May. Generally pancratistatin [1] was accompanied by lesser yields of narciclasine [2], 7-deoxynarciclasine [3], and 7-deoxy-trans-dihydronarcicasine [4], Improved laboratory and pilot-plant scale techniques were also developed for the isolation of pancratistatin [1] from difficult-to-separate mixtures of narciclasine [2] and 7-deoxynarciclasine [3] occurring in H. littoralis.