Antioxidant, Cytotoxic, and Acetylcholinesterase Inhibitory Activities of Withanolides from Datura quercifolia

Abstract Five withanolides identified as daturalactone (1) , withanicandrin (2), withanolide B (3), nicandrin B (4), and daturalactone 2 (5) were isolated from the aerial parts (flowers, leaves, and stems) of Datura quercifolia Kunth. Their structures were determined by analysis of the IR, MS, 1D and 2D NMR spectra. All the isolates were evaluated for their cytotoxic and antioxidant activities, as well as for their capacity to inhibit the activity of the acetylcholinesterase enzyme (AChE). As result, the five withanolides showed weak cytotoxic and pro-oxidant activities, however, they displayed a relevant inhibitory activity against AChE, as indicated by the IC50 values ranging from 1.51 to 12.11 µM. The differences in AChE inhibition seem to be related to the functional group at C-12.