Indole Diterpene Derivatives from the Aspergillus flavus GZWMJZ-288, an Endophytic Fungus from Garcinia multiflora .

A new indole diterpene, 26-dihydroxyaflavininyl acetate ( 1 ), along with five known analogs ( 2 - 6 ) were isolated from the liquid fermentation of Aspergillus flavus GZWMJZ-288, an endophyte from Garcinia multiflora . The structures of these compounds were identified through NMR, MS, chemical reaction, and X-ray diffraction experiments. Enzyme inhibition activity screening found that compounds 1 , 4 , and 6 have a good binding affinity with NPC1L1, among which compound 6 exhibited a stronger binding ability than ezetimibe at a concentration of 10 µM. Moreover, compound 5 showed inhibitory activity against α -glucosidase with an IC 50 value of 29.22 ± 0.83 µM, which is 13 times stronger than that of acarbose. The results suggest that these aflavinine analogs may serve as lead compounds for the development of drugs targeting NPC1L1 and α -glucosidase. The binding modes of the bioactive compounds with NPC1L1 and α-glucosidase were also performed through in silico docking studies.