Chemical constituents of Camellia kissi leaves with α -glucosidase, acetylcholinesterase, and nitric oxide inhibitory effects

One new phenolic glycoside, eugenyl O-β-D-allopyranoside (1), along with 11 known compounds, including sasanquin (2), vomifoliol (3), (6 R,9S)-3-O-oxo-α-ionol β-D-glucopyranoside (4), (+)-lyoniresinol 4-O-β-D-glucopyranoside (5), nudiposide (6), icariside E4 (7), dihydrodehydrodiconiferyl alcohol (8), 3β-hydroxy-olean-11,13(18)-dien-28-oic acid (9), oleanolic acid (10), 3,4,3′-tri-O-methylellaic acid (11), and kaempferol 3-O-α-L-rhamnopyranoside (12) were isolated from the leaves of Camellia kissi Wall. All compounds were evaluated for inhibitory activities against acetylcholinesterase, α-glucosidase, and nitric oxide production. As a result, compound 1 showed a significant inhibitory effect on acetylcholinesterase with an IC50 value of 10.09 ± 0.61 µM. Compounds 9 and 10 showed significant inhibitory α-glucosidase activity with an IC50 value of 17.62 ± 1.32 and 33.99 ± 1.97 µM, respectively. Compounds 2 and 9 showed significant nitric oxide inhibitory activity with IC50 values of 19.87 ± 1.09 and 16.74 ± 0.66 µM, respectively. These results represent the first phytochemical investigation and biological screening of constituents from C.kissi.