Three New Pteridines from the LeechWhitmania pigra

Abstract Chemical investigation on the dried material of the leech Whitmania pigra has led to the isolation of three new pteridines, including two new lumazines bearing a thieno[3,2-g]lumazine skeleton, whitmanines A and B (1 and 2) and a new pterin, 5,8-dimethylleucopterin (3). Their structures were established mainly by spectroscopic methods, especially HR-ESI-MS and NMR techniques.