BIOSYNTHESIS OF THE INDOLIZIDINE ALKALOID CYCLIZIDINE - INCORPORATIONOF SINGLY AND DOUBLY LABELED PRECURSORS

Incorporation of (CH3CO2Na)-C-13-O-18 and (CD3CH2CO2Na)-C-13 into the indolizidine alkaloid cyclizidine 1, produced by Streptomyces species NCIB 11649, shows that the oxygen attached to C-2 is derived intact fr om acetate and that the cyclopropyl ring is derived from a single inta ct propionate unit. However, the level and stereochemistry of the inco rporation of deuteriated sodium propionate indicates that it undergoes unexpected modification during incorporation into the cyclopropyl rin g.