Secondary metabolites from a peanut-associated fungus <i>Aspergillus niger</i> IMBC-NMTP01 with cytotoxic, anti-inflammatory, and antimicrobial activities
Trần Hồng Quang, Nguyen Viet Phong, Lê Ngọc Ánh, Trần Thị Hồng Hạnh, Nguyễn Xuân Cường, Nguyễn Thị Thanh Ngân, Nguyen Quang Trung, Nguyễn Hoài Nam, Châu Văn Minh
Abstract
Chemical investigation of a peanut-associated fungal strain Aspergillus niger IMBC-NMTP01 resulted in isolation and identification of 14 secondary metabolites, including two new, epi-aspergillusol (1) and aspernigin (3), and 12 known compounds: pyrophen (2), 2-(hydroxyimino)-3-(4-hydroxyphenyl)propanoic acid (4), aspergillusol A (5), rubrofusarin B (6), nigerasperone A (7), fonsecin (8), TMC-256C1 (9), pyranonigrin A (10), orlandin (11), nigerasperone C (12), asperpyrone A (13), and 5-(hydroxymethyl)-2-furancarboxylic acid (14). Compounds 9, 12-14 showed cytotoxicity toward all six human cancer cell lines, including HepG2, KB, HL-60, MCF-7, SK-Mel2, and LNCaP, with IC50 values ranging from 8.4 to 84.5 µM, compounds 3-5 were cytotoxic against five cancer cell lines except HepG2, whereas 1 exhibited cytotoxicity toward HepG2, KB, and MCF-7 cells. All of the compounds, except 2 and 13, inhibited NO overproduction in LPS-induced RAW264.7 cells. In addition, all of the compounds displayed antimicrobial effects against Enterococcus faecalis, whereas 13 compounds, except 10, significantly inhibited the growth of the yeast Candida albicans.