Anticholinesterase and β-Site Amyloid Precursor Protein Cleaving Enzyme 1 Inhibitory Compounds from the Heartwood of Juniperus chinensis

Two new compounds (2, 3) and 20 known compounds (1, 4-22) were isolated from the heartwood of Juniperus chinensis LINNE (Cupressaceae), and their structures were elucidated as 9'-methoxycalocedrin (1); α-methyl artoflavanocoumarin (2); 5,7,4'-trihydroxy-2-styrylchromone (3); cedrol (4); widdrol (5); savinin (6); calocedrin (7); 10-oxowiddrol (8); 12-hydroxywiddrol (9); (+)-naringenin (10); vanillic acid methyl ester (11); (+)-taxifolin (12); (+)-aromadendrin (13); kaempferol (14); quercetin (15); (7S,8R)-dihydro-3'-hydroxy-8- hydroxymethyl-7-(4-hydroxy-3-methoxyphenyl)-1'-benzofuranpropanol (16); styraxlignolide C (17); protocatechuic acid (18); vanillic acid (19); (7R,8S)-dihydro-3'-methoxy-8-hydroxymethyl-7-(4-hydroxy-3-methoxyphenyl)-1'-benzofuranpropanol 4-O-β-D-glucopyranoside (20); (7S,8S)-dihydro-3'-hydroxy-8-hydroxymethyl-7-(4-hydroxy-3-methoxyphenyl)-1'-benzofuranpropanol 4-O-α-L-rhamnopyranoside (21); and (+)-catechin (22) on the basis of spectroscopic evidence. The new compounds (2, 3) exhibited good inhibitory activities against β-site amyloid precursor protein cleaving Enzyme 1 (BACE1), with IC50 values of 6.25, and 11.91 µM, respectively.