BACE1 (beta-secretase) inhibitory phenolic acids and a novel sesquiterpenoid from Homalomena occulta.

Four phenolic acids, namely 2-[(Z)-heptadec-11-enyl]-6-hydroxybenzoic acid (1), 2-[(6Z,9Z,12Z)-heptadeca-6,9,12-trienyl]-6-hydroxybenzoic acid (2), 2-[(9Z,12Z)-heptadeca-9,12-dienyl]-6-hydroxybenzoic acid (3), and 2-hydroxy-6-(12-phenyldodecyl)benzoic acid (4), and one sesquiterpene, asperpenoid (5), were isolated from the 95% EtOH extract of the roots of Homalomena occulta, among which 1, 2, and 5 represent new compounds. Further, the phenolic acids 1-4 exhibited BACE1 (beta-secretase) inhibitory activity with IC(50) values of 6.23+/-0.94, 6.28+/-0.63, 7.93+/-0.38, and 7.65+/-0.62 microM, respectively.