A new fatty ester and a new triterpene from Skimmia laureola

Aerial parts of Skimmia laureola yielded a new fatty ester, (+)-skimmilaureol (1), and a new triterpene 16-29-dihydroxy, 20-ene cyclolaudenol (2). Five known compounds, namely, O-methyl-cyclolaudenol (3), (R)-7-methoxy-6-(3'-hydroxy-2'R-methoxy-3'-methyl butyl)coumarin (4), (+)-(S)-psi-ribalinine (5), (R)-(+)-ribalinine (6) and methyl isoplatydesmine (7), previously isolated from this plant were subjected to enzymatic bioassays for the first time. Compounds 3 and 4 were found to be prolyl endopeptidase inhibitors with IC(50) 8.21 +/- 0.407 and 39.63 +/- 1.502 microM, respectively, while compounds 5-7 were found to be acetyl-cholinesterase and butyryl-cholinesterase inhibitors with IC(50) 62.46 +/- 1.58, 153.31 +/- 1.9, 74.5 +/- 1.05 and 150.04 +/- 0.45, 12.99 +/- 0.31, 78.3 +/- 1.86 microM, respectively.