Cytotoxic Norsesquiterpene Peroxides from the Endophytic Fungus Talaromyces flavus Isolated from the Mangrove Plant Sonneratia apetala

Abstract

Four new norsesquiterpene peroxides, named talaperoxides A-D (1-4), as well as one known analogue, steperoxide B (5, or merulin A), have been isolated from a mangrove endophytic fungus, Talaromyces flavus. Their structures were elucidated mainly by 1D and 2D NMR. Structures of 1, 2, and 5 were further confirmed by single-crystal X-ray diffraction, and their absolute configurations were also determined using copper radiation. Cytotoxic activities of compounds 1-5 were evaluated in vitro against human cancer cell lines MCF-7, MDA-MB-435, HepG2, HeLa, and PC-3. Compounds 2 and 4 showed cytotoxicity against the five human cancer cell lines with IC50 values between 0.70 and 2.78 μg/mL.

Peroxy natural products

“…208 The structures of 359, 360, 366 and 367 were further confirmed by X-ray crystallographic analysis, and the absolute configurations of the latter three compounds were also determined using copper radiation 204,206,208 Five peroxy cuparene-type sesquiterpenoids 370-374 were identified from the Japanese liverwort Jungermannia infusca. The stereostructure of 370 was confirmed by X-ray crystallographic analysis.…”

Antifungal Polyketides and Other Compounds from Amazonian Endophytic Talaromyces Fungi

“…2 Among distinct types of fungi present in this environment, endophytes are receiving attention due to their ability to produce biologically active natural products. 3,4 Endophytic strains of Talaromyces are still poorly studied, with few works reporting mainly secondary metabolites from the alkaloid, 5 terpene, 6 and polyketide classes. 7 Some of the described compounds possess remarkable pharmacological activities.…”

Three Pairs of New Isopentenyl Dibenzo[b,e]oxepinone Enantiomers from Talaromyces flavus, a Wetland Soil-Derived Fungus

“…Talaromyces flavus, the commonest species of the genus Talaromyces, has been reported to produce a series of bioactive compounds [8,9]. In our search for bioactive secondary metabolites from wetland fungi [10][11][12][13][14][15], several interesting molecules also had been isolated from this species [12][13][14][15].…”