Two undescribed diarylheptanoids, 3-(R)-acetyl-1-(3',4'-dihydroxyphenyl)-7-(4''-hydroxy-3'' -methoxyphenyl)-heptane (1) and 11-Hydroxy-1,17-epoxy-7-(2-hydroxylphenyl)-13-(16-methoxyphenyl)-heptane (2) together with known compounds, namely, 11-Oxo-1,17-epoxy-7-(2-hydroxylphenyl)-13-(16-methoxyphenyl)-heptane (3) 3,4,5-Trihydroxytetralone (4) 4,8- Dihydroxytetralone (5), 4,5-Dihydroxytetralone (6), 5,8-Dihydroxy-3-methoxytetralone (7) were isolated from ethyl acetate extract of the green husk of Carya illinoinensis. The structures of compounds were established on the basis of IR, 1H NMR, 13C NMR, DEPT, HSQC, HMBC, COSY spectroscopic and ESI-MS analysis. The isolated compounds were evaluated for AChE (acetylcholinesterase inhibition) and observed that compound 5 was potent inhibitor with IC50 of 101.48 ± 4.00 µg/mL.
Keywords: Carya illinoinensis; acetylcholineesterase inhibition; diarylheptanoids; structure elucidation; tetralones.