Bioactive Metabolites from Mangrove Endophytic Fungus Aspergillus sp. 16-5B

Abstract

Chemical investigation of the endophytic fungus Aspergillus sp. 16-5B cultured on Czapek’s medium led to the isolation of four new metabolites, aspergifuranone (1), isocoumarin derivatives (±) 2 and (±) 3, and (R)-3-demethylpurpurester A (4), together with the known purpurester B (5) and pestaphthalides A (6). Their structures were determined by analysis of 1D and 2D NMR spectroscopic data. The absolute configuration of Compound 1 was determined by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra, and that of Compound 4 was revealed by comparing its optical rotation data and CD with those of the literature. The structure of Compound 6 was further confirmed by single-crystal X-ray diffraction experiment using CuKα radiation. All isolated compounds were evaluated for their α-glucosidase inhibitory activities, and Compound 1 showed significant inhibitory activity with IC50 value of 9.05 ± 0.60 μM. Kinetic analysis showed that Compound 1 was a noncompetitive inhibitor of α-glucosidase. Compounds 2 and 6 exhibited moderate inhibitory activities.

Naturally Occurring Isocoumarins Derivatives from Endophytic Fungi: Sources, Isolation, Structural Characterization, Biosynthesis, and Biological Activities

“…For the extraction and isolation of isocoumarins, the fungal material was extracted with CH 2 Cl 2 , acetone or EtOAc. The total extracts were partitioned between n-hexane, CHCl 3 , EtOAc, and MeOH or fractionated on SiO 2 60 VLC using mixtures of n-hexane, EtOAc, and MeOH, or using petroleum ether, CH 2 Cl 2 , and MeOH, respectively [38][39][40]. The fractions were chromatographed over Sephadex LH-20 (CHCl 3 :MeOH 1:1), SiO 2 CC using gradient elution of CH 2 Cl 2 :MeOH; PE:EtOAc; n-hexane:EtOAc [31,36,37,[41][42][43] or RP-18 CC using MeOH-H 2 O (8:2, v/v) [33].…”

Polyketides with Immunosuppressive Activities from Mangrove Endophytic Fungus Penicillium sp. ZJ-SY2

“…In the past decades, our research group had been focusing on the exploration of new bioactive metabolites from mangrove endophytic fungi collected from the South China Sea [6,7,8,9,10,11,12,13]. The EtOAc extract of the fermentation of a mangrove endophytic fungus, Penicillium sp.…”

Antimicrobial and Cytotoxic Activities of Endophytic Fungi Isolated from Mangrove Plant Sonneratia alba Sm

“…The fungus was isolated from the leaves of Sonneratia apetala from Dongzhaigang Mangrove National Nature Reserve in Hainan Island, China. All isolated compounds were evaluated for their α-glycosidase inhibitory activities, and Aspergifuranone showed significant inhibitory activity with an IC 50 value of 9.05 ± 0.60 μM (Liu et al, 2015). A. sydowii has been reported mainly from marine sources and produce some biologically active compounds.…”