Isochaihulactone analogues: synthesis and anti-proliferative activity of novel dibenzylbutyrolactones.

A series of dibenzyl-γ-butyrolactones bearing a hydroxyl group at the benzylic position of 3-benzyl group were synthesized as hydrated analogue of isochaihulactone and evaluated against breast cancer human cell lines (MDA-M231, MCF-7 and T47D). The target compounds were synthesized in 7 steps from known lactone; (S)-(+)-γ-benzyloxymethyl-γ-butyrolactone. The key step was the aldol condensation between (+)-(R)-β-(benzo[d][1,3]dioxol-5-ylmethyl)-γ-butyrolactone and substituted benzaldehydes which afforded corresponding α-hydroxybenzyl butyrolactone analogues. The cytotoxic study of the synthesized compounds against breast cancer human cell lines showed that some of them inhibit breast cancer human cell proliferation with percentage inhibitions over 50% at concentrations less than 50 μg/mL.