Chemical constituents from fruits of Cnestis ferruginea Vahl ex. DC (Connaraceae) and evaluation of their anticholinesterase and antiradical activities

The phytochemical investigation of the DCM/MeOH (1:1) extract of the fruits of Cnestis ferruginea led to the isolation and characterization of one new quinic acid derivative, ferruginoic acid (1), together with six known compounds 2–7. Compounds 3–7 were reported for the first time from this species. The structures of compounds 1–7 were elucidated on the basis of 1 D and 2 D NMR spectroscopic data, mass spectrometry and by comparison of spectroscopic data with those from the literature. The anticholinesterase (AChE and BChE) activity and DPPH free radical scavenging assay of compounds 1, 3, 4 and 7 were evaluated. Ferruginoic acid (1) exhibited moderate anticholinesterase activity with IC₅₀ value of 36.18 ± 1.78 µg/mL against AChE. Compounds 3, 4 and 7 showed high activity against free radical (DPPH^•) scavenging assay (DPPH) with IC₅₀ values 40.09 ± 0.96 µg/mL, 61.70 ± 0.78 µg/mL and 41.87 ± 0.62 µg/mL respectively. These results indicate that C. ferruginea and its constituents could be employed in the management of Alzheimer’s disease.