α-Glucosidase Inhibitors From the Coral-Associated Fungus Aspergillus terreus

• Published in: Frontiers in chemistry 2018-09, Vol.6, p.422-422
• Main Authors: Liu, Mengting, Qi, Changxing, Sun, Weiguang, Shen, Ling, Wang, Jianping, Liu, Junjun, Lai, Yongji, Xue, Yongbo, Hu, Zhengxi, Zhang, Yonghui
• Format: Article
• Language: English
• Subjects: Aspergillus terreus; butenolide derivatives; Chemistry; coral-associated fungus; structure reassignments; α-glucosidase inhibitors
• ISSN: 2296-2646; 2296-2646
• DOI: 10.3389/fchem.2018.00422

Nine novel butenolide derivatives, including four pairs of enantiomers, named (±)-asperteretones A-D ( ), and a racemate, named asperteretone E ( ), were isolated and identified from the coral associated fungus . All the structures were established based on extensive spectroscopic analyses, including HRESIMS and NMR data. The chiral chromatography analyses allowed the separation of (±)-asperteretones A-D, whose absolute configurations were further confirmed by experimental and calculated electronic circular dichroism (ECD) analysis. Structurally, compounds - represented the first examples of prenylated γ-butenolides bearing 2-phenyl-3-benzyl-4 -furan-1-one motifs, and their crucial biogenetically related metabolite, compound , was uniquely defined by an unexpected cleavage of oxygen bridge between C-1 and C-4. Importantly, (±)-asperteretal D and (4 )-4-decarboxylflavipesolide C were revised to (±)-asperteretones B ( / ) and D ( ), respectively. Additionally, compounds and were evaluated for the α-glucosidase inhibitory activity, and all these compounds exhibited potent inhibitory potency against α-glucosidase, with IC values ranging from 15.7 ± 1.1 to 53.1 ± 1.4 μM, which was much lower than that of the positive control acarbose (IC = 154.7 ± 8.1 μM), endowing them as promising leading molecules for the discovery of new α-glucosidase inhibitors for type-2 diabetes mellitus treatment.