Tổng hợp tetrahydrocurcumin từ curcumin

Abstract

Tetrahydrocurcumin (THC) is 1.7-bis(4-hydroxy-3-methoxyphenyl)-heptane-3.5-dione with the empirical formula C₂₁H₂₄O₆ and a molecular weight 372 g/mol, and is a bioactive beta-diketone compound. It can be isolated from turmeric (Curcuma longa L.) or semi-synthesised from curcumin. THC could inhibit lipid peroxidation in erythrocyte membranes induced by tert-butyl hydroperoxide, showing a greater effect than curcumin, as well as ameliorate oxidative stress-induced renal injury. In addition, THC possesses anti-inflammatory, antioxidant, and anti-aging activities. In this article, THC was semi-synthesised from curcumin using two methods. In the first approach, curcumin was acetylated with acetic anhydride in pyridine to afford curcumin acetyl (1) to form THC-acetyl (2) via the catalytic hydrogenation using 10% Pd/C in EtOH at room temperature, followed by deacetylation with NaOH 8% at pH 9 to yield THC (3). In the second method, catalytic hydrogenation in the presence of 10% Pd/C in solvent or EtOH/NaOH (solid), or EtOH/NH₄OH 25% at room temperature to obtain THC (3) in good yields. The structures of the compounds were confirmed by nuclear magnetic resonance (NMR) and liquid chromatography-electrospray ionisation mass spectrometry (LC-ESI-MS).