Haenamindole and fumiquinazoline analogs from a fungicolous isolate of Penicillium lanosum

Abstract

Three amino acid-derived compounds, haenamindole (1) and 2'-epi-fumiquinazolines C (2) and D (3), were isolated from cultures of a fungicolous isolate of Penicillium lanosum (MYC-1813=NRRL 66231). Compound 1 was also encountered in cultures of P. corylophilum (MYC-418=NRRL 28126). Structure elucidation of these metabolites was based mainly on high resolution mass spectrometry and NMR data analysis. Haenamindole (1) was found to be a recently reported diketopiperazine-type metabolite that incorporates an unusual β-Phe unit. Analysis of X-ray crystallographic data and the products of acid hydrolysis of 1 enabled a conclusive, slightly modified stereochemical assignment for haenamindole. Fumiquinazoline analog 2 is a new natural product, while related compound 3 has been previously reported only as a product of an in vitro enzymatic step and of a genetically engineered fungal culture. Compounds 1 and 3 showed antiinsectan activity against the fall armyworm Spodoptera frugiperda.