Cholinesterase-inhibitory diterpenoids and chemical constituents from aerial parts of Caryopteris mongolica

A diterpenoid diglucoside (12,19-di-O-beta-d-glucopyranosyl-11-hydroxyabieta-8,11,13-triene-19-one), isoscutellarein 7-O-[beta-d-xylopyranosyl-(1 -> 2)]-beta-d-glucopyranoside, isoscutellarein 7-O-[alpha-l-rhamnopyranosyl-(1 -> 2)]-beta-d-glucopyranoside, hypolaetin 7-O-[6aEuro(3)-O-(p-E-coumaroyl)]-beta-d-glucopyranoside, hypolaetin 7-O-[6aEuro(3)-O-(E-caffeoyl)]-beta-d-glucopyranoside, and 15 known compounds were isolated from aerial parts of the Mongolian medicinal plant Caryopteris mongolica. The cholinesterase-inhibitory activities of the constituents were estimated. The abietane diterpenoids (12-O-demethylcryptojaponol and 6 alpha-hydroxydemethylcryptojaponol) showed potent inhibitory activity against acetylcholinesterase from human erythrocytes and electric eel, and against butyrylcholinesterase from horse serum.