Comparison of the bioactive secondary metabolites from the scale insect pathogens, Anamorph Paecilomyces cinnamomeus, and Teleomorph Torrubiella luteorostrata

Abstract

A scale insect pathogen Paecilomyces cinnamomeus BCC 9616 and its teleomorph Torrubiella luteorostrata BCC 9617, collected on the same host specimen, were fermented and chemically explored. Both fungi produced paecilodepsipeptide A (1) and zeorin (4) as major constituents of mycelia extracts. The culture broth extract of BCC 9616 provided a known diketopiperazine, terezine D (5), and a new xanthone glycoside, norlichexanthone-6-O-β-(4-O-methylglucopyranoside) (6). On the other hand, the broth extract of BCC 9617 contained small amounts of a new naphthopyrone glycoside, rubrofusarin-6-O-β-(4-O-methylglucopyranoside) (7) along with 5. Structures of the new compounds, 6 and 7, were elucidated by interpretation of NMR and mass spectroscopic data. The overall results demonstrated that the metabolite profiles of the cultured anamorph (BCC 9616) and teleomorph (BCC 9617) originating from the same host specimen resemble each other closely. The 1H-NMR spectroscopic analysis of the culture extracts from other strains of P. cinnamomeus and T. luteorostrata revealed that zeorin is the most commonly occurring fermentation product of these fungi, whereas paecilodepsipeptide A was the metabolite specific to the particular isolate BCC 9616/BCC 9617. © Japan Antibiotics Research Association.