1,2,3,4,6-penta-O-galloyl-β-d-glucose: A cholinesterase inhibitor from Terminalia chebula

The search for a novel pharmacotherapy from medicinal plants for neurodegenerative disorders has significantly advanced. Therefore, the present study was performed to evaluate the anticholinesterase activities of one hundred medicinal plants in Korea, where Terminalia chebula (T. chebula) fruits showed significant acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitions. Further bioassay monitored phytochemical exploration led to the isolation of 1,2,3,4,6-penta-O-galloyl-β-d-glucose (compound 1), which showed significant AChE and BChE inhibitory effects with IC50 values of 29.9 ± 0.3 µM and 27.6 ± 0.2 µM, respectively. The inhibitory effect of compound 1 towards acetylcholinesterase was also evaluated using TLC and compared with tacrine as the positive control; the positive effect was confirmed. Furthermore, compound 1 also displayed strong antioxidant activity by the FRAP assay (IC50 = 4.6 ± 0.2 µM). In conclusion, compound 1 may prove to be a potential natural anti-Alzheimer source based on noteworthy AChE and BChE inhibitions, and strong antioxidant activity.