L-687,781, a new member of the papulacandin family of beta-1,3-D-glucan synthesis inhibitors. I. Fermentation, isolation, and biological activity.

A new β-1, 3-D-glucan synthesis inhibitor, L-687, 781 is produced by the cultivation of Dictyochaeta simplex ATCC 20960. L-687, 781 exhibits potent in vitro antifungal activity as well as anti-Pneumocystis activity in a rat model.