Isoflavonoids from Ficus benjamina and their inhibitory activity on BACE1

Abstract

Examination of an active extract of the fruit of Ficus benjamina var. nuda (Miq.) Barrett has led to the isolation of six new isoflavones and two coumarano-chroman-4-ones, along with fifteen known compounds. The structures of the eight new compounds were elucidated on the basis of extensive NMR experiments and mass spectrometric measurements. The inhibitory activity of the compounds on the proteolytic cleavage of amyloid precursor protein by the aspartic protease BACE1 was evaluated. Both coumarano-chroma-4-ones and some isoflavones showed moderate activity in this assay.

Fig. 1

Chemical structures of compounds 1-8.

Fig. 2

Selected HMBC (H → C) correlations of 1.

Fig. 3

Selected HMBC (H → C) and ROESY (↔) correlations of 3.