Pradimicins T1 and T2, new antifungal antibiotics produced by an actinomycete. II: Structures and biosynthesis

Pradimicins T1 and T2 are new members of the pradimicin family of antibiotics produced by an actinomycete strain AA3798. Pradimicins T1 and T2 are dihydrobenzo[a]naphthacenequinones substituted with 3 and 2 sugar moieties, respectively. The salient feature in their structures is an L-xylose attached to the phenolic hydroxyl group at C-11. Bioconversion experiments using a blocked mutant B-54 of strain AA3798 not only explored a plausible biosynthetic pathway of pradimicins T1 and T2, but also provided evidence of 5S, 6S configuration.