Nigerasperones A~C, New Monomeric and Dimeric Naphtho-γ-pyrones from a Marine Alga-derived Endophytic Fungus Aspergillus niger EN-13

Abstract

Three new naphtho-g-pyrones, 5-hydroxy-6,8-dimethoxy-2-hydroxymethyl-4H-naphtho [2,3-b]pyran-4-one (1, nigerasperone A), 3,3Ј-dihydro-2,2Ј,5,5Ј-tetrahydroxy-8,8Ј,10,10Ј-tetramethoxy-2,2Ј-dimethyl-(6Ј,9-bi-4H-naphtho[1,2-b]pyran)-4,4Ј-dione (2, nigerasperone B), and 3Ј-hydro-2Ј,5,5Ј,8-tetrahydroxy-6,6Ј,8Ј-trimethoxy-2,2Ј-dimethyl-(7,10Ј-bi-4H-naphtho[2,3-b]pyran)-4,4Ј-dione (3, nigerasperone C), together with nine related known compounds were characterized from Aspergillus niger EN-13, an endophytic fungus isolated from the marine brown alga Colpomenia sinuosa. Their structures were elucidated by detailed analysis of spectroscopic data and by comparison with literature reports. In the cytotoxic assay, these compounds did not show remarkable inhibitory effects against A549 and SMMC-7721 tumor cell lines. However, 3 and several known compounds showed weak antifungal activity against Candida albicans and moderate activity on DPPH scavenging.

Secondary Metabolites from a Marine-Derived Endophytic Fungus Penicillium chrysogenum QEN-24S

“…In the past years, a number of new metabolites have been isolated and identified and their biological activities have been evaluated [2–4]. As part of our recently initiated program to assess the chemical and biological diversity of endophytic fungi derived from marine algae [5–12], Penicillium chrysogenum QEN-24S, an endophytic fungus obtained from the inner tissue of an unidentified marine red algal species of the genus Laurencia , attracted our attention. This fungus displayed inhibitory activity against the growth of pathogenic fungus Alternaria brassicae in our initial dual culture test (Figure 1).…”

New naphthopyrones from marine-derived fungus Aspergillus niger 2HL-M-8 and their in vitro antiproliferative activity

“…The 13 C NMR and HSQC spectra revealed that compound 1 contained 34 carbons, including two methyl groups, four methoxy groups, one sp 3 methine, one sp 3 methylene, six sp 2 methines, 20 quaternary sp 2 carbons, with two being conjugated carbonyls. The above evidences were indicative of a dimer consisting of two linear naphtho-g-pyrone monomers (Akiyama et al 2003;Zhang et al 2007).…”

Advances in Marine Microbial Symbionts in the China Sea and Related Pharmaceutical Metabolites

“…[32]. A new naphthoquinoneimine derivative, 5,7-dihydroxy-2-[1-(4-methoxy-6-oxo-6H-pyran-2-yl)-2-phenylethylamino]-[1,4]-naphthoquinone ( 30 ), and asperamides A ( 31 ), nigerasperone C ( 32 ) from the marine brown alga Colpomenia sinuosa- derived endophytic fungus Aspergillus niger EN-13 displayed moderate activity against Candida albicans [33–35]. Chaetopyranin ( 33 ) isolated from Chaetomium globosum , an endophytic fungus derived from the marine red alga Polysiphonia urceolata , exhibited moderate to weak cytotoxic activity [36].…”