HIV-1 protease inhibitory substances from Cassia garrettiana

Abstract

Cassia garrettiana Craib, a Thai medicinal plant locally known as Samae-sarn, was investigated for its active constituents against HIV-1 protease (HIV-1 PR). Bioassay-guided fractionation of the heart woodof this plant led to the isolation of a stilbene derivative (1, piceatannol) and an anthraquinone derivative (2, chrysophanol). Piceatannol exhibited appreciable inhibitory effect against HIV-1 PR with an IC50 value of25.4 μg/ml, whereas that of chrysophanol was 73.5 μg/ml. In addition, other two stilbenoids together with three anthraquinone derivatives were also investigated for their anti-HIV-1 PR activities. The resultindicated that resveratrol possessed anti-HIV-1 PR activity with an IC50 value of 85.0 μg/ml, whereas other stilbenoid (oxyresveratrol) and anthraquinone derivatives (emodin, aloe-emodin, rhein) were inactive (IC50 > 100 μg/ml).

Keywords

• HIV-1 protease
• inhibitory substances
• Cassia garrettiana