α-Glucosidase Inhibitors: Diphenyl Ethers and Phenolic Bisabolane Sesquiterpenoids from the Mangrove Endophytic Fungus Aspergillus flavus QQSG-3
Yingnan Wu,
Yan Chen,
Xishan Huang,
Yahong Pan,
Zhaoming Liu,
Tao Yan,
Wenhao Cao,
Zhigang She
Affiliations
Yingnan Wu
School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
Yan Chen
South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine Sciences, Sun Yat-Sen University, Guangzhou 510006, China
Xishan Huang
School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
Yahong Pan
School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
Zhaoming Liu
School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
Tao Yan
CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
Wenhao Cao
CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Key Laboratory of Marine Materia, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
Zhigang She
School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
Two new diphenyl ethers (1 and 2) and four new phenolic bisabolane sesquiterpenoids (3–6), together with five known related derivatives, were isolated from the culture of the endophytic fungus Aspergillus flavus QQSG-3 obtained from a fresh branch of Kandelia obobata, which was collected from Huizhou city in the province of Guangdong, China. The structures of compounds 1–6 were determined by analyzing NMR and HRESIMS data. The absolute configurations of 5 and 6 were assigned by comparing their experimental ECD spectra with those reported for similar compounds in the literature. All isolates were evaluated for their α-glucosidase inhibitory activity, of which compounds 3, 5, 10, and 11 showed strong inhibitory effects with IC50 values in the range of 1.5–4.5 μM.
