Abstract
The biosynthesis of lasiodiplodin (1) and its (5S)-5-hydroxylated derivative (2) were investigated by the administration of 13C-labeled acetates to Lasiodiplodia theobromae. The labeling patterns of biosynthetically 13C-labeled 1 and 2 were determined by 13C-NMR and INADEQUATE spectra, demonstrating the octaketide origins of 1 and 2. Taking into account the biosynthetic study of resorcylic acid lactones, the involvement of highly reduced acyl intermediates in the biosynthesis of lasiodiplodins was presumed; thus, we synthesized 2H-labeled hypothetical acyl intermediates of 1, 9-hydroxydecanoic acid (4) and its N-acetylcysteamine thioester (SNAC, 5). When L. theobromae was incubated with 5 mM of a 2H-labeled intermediate, the 2H-label from the intermediate was incorporated at the expected position of 1. These incorporation studies revealed that 1 was produced via a pathway which closely resembles that of resorcylic acid lactone biosynthesis.
