INHIBITORS OF MYOINOSITOL MONOPHOSPHATASE, ATCC-20928 FACTOR-A AND FACTOR-C - ISOLATION, PHYSICOCHEMICAL CHARACTERIZATION AND BIOLOGICAL PROPERTIES

During the course of a screening program for inhibitors of myo-inosito l monophosphatase we fermented the strain ATCC 20928, a known producer of L-671,776. We now show that this strain produces a complex of at l east three sesquiterpenic compounds, L-671,776 (termed factor B) and t wo structurally related substances, termed factors A and C. Both facto rs A and C, like L-671,776, exhibited inhibitory activity against myo- inositol monophosphatase. Six other fungi producing the above mentione d compounds were also isolated and taxonomically characterized.