Prof. Guo Yuewei’s group in Shanghai Institute of Materia Medica, CAS has been committed to the research on the secondary metabolites from Chinese mangrove plants Bruguiera gymnorrhiza. Researchers have obtained series of structurally novel macrocyclic polydisulfides and spirodioxynaphthalenes.

These compounds showed significant inhibitory activity towards hPTP1B (human protein tyrosine phosphatase 1 B), a potential drug target for the treatment of Type II diabetes, and cytotoxic activity in vitro, respectively.

In the course of continuing efforts aimed at finding new bioactive substances and giving new insights into the pathway for their biosynthesis, the endophytic fungal strains isolated from the Chinese mangrove B. gymnorrhiza was selected and chemically studied for further investigation.

A novel pyrrolizidine alkaloid, penibruguieramine A, characterized by an unprecedented 1-alkenyl-2-methyl-8-hydroxymethylpyrrolizidin-3-one skeleton, was isolated from the endophytic fungus Penicillium sp., associated with the Chinese mangrove B. gymnorrhiza The absolute configuration of penibruguieramine A was established by TDDFT-ECD calculations of the vacuum and solution conformers, exploiting the transitions of the lactam chromophore.

The result has been published online on “Organic Letters” (DOI: 10.1021/ol5001523) and selected as ‘Hot off the press’ by authoritative journal “Natural Product Reports”.

Structure of penibruguieramine A（Image By SIMM）