Penicamide A, A Unique N,N'-Ketal Quinazolinone Alkaloid from Ascidian-Derived Fungus Penicillium sp. 4829.

ABSTRACT: Previously unreported N,N'-ketal quinazolinone enantiomers [(-)-1 and (+)-1] and a new biogenetically related compound (2), along with six known compounds, 2-pyrovoylaminobenzamide (3), N-(2-hydroxypropanoyl)-2 amino benzoic acid amide (4), pseurotin A (5), niacinamide (6), citreohybridonol (7), citreohybridone C (8) were isolated from the ascidian-derived fungus Penicillium sp. 4829 in wheat solid-substrate medium culture. Their structures were elucidated by a combination of spectroscopic analyses (1D and 2D NMR and Electron Circular Dichroism data) and X-ray crystallography. The enantiomeric pair of 1 is the first example of naturally occurring N,N'-ketal quinazolinone possessing a unique tetracyclic system having 4-quinazolinone fused with tetrahydroisoquinoline moiety. The enantiomeric mixtures of 1 displayed an inhibitory effect on NO production in lipopolysaccharide-activated RAW264.7 cells, while the optically pure (-)-1 showed better inhibitory effect than (+)-1.

SUBMITTER: Chen S 

PROVIDER: S-EPMC6780914 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature