Enzymatic Activation of the Emerging Drug Resveratrol.

The plant originated stilbene "resveratrol" (3,4',5-trans-trihydroxystilbene) is well known for its diverse health benefits including anti-tumor, anti-inflammatory, anti-microbial, and anti-oxidant properties. Besides a significant amount of reports on different aspects of its application as prodrug in the last 50 years, still, a strategy leading to the production of the active drug is missing. The aim of this work was to evaluate the enzymatic activation of prodrug resveratrol to the effective drug piceatannol, without engaging expensive cofactors. Five different heme proteins were analyzed for the transformation of resveratrol. Kinetic parameters of resveratrol transformation and analysis of the transformed products were conducted through HPLC and GC-MS. Effect of pH and organic solvent on the transformation process had also been evaluated. Among all tested heme proteins, only a variant of cytochrome P450BM3 from Bacillus megaterium (CYPBM3F87A) was found suitable for piceatannol production. The most suitable pH for the reaction conditions was 8.5, while organic solvents did not show any effect on transformation. For resveratrol transformation, the turnover rate (k cat) was 21.7 (± 0.6) min-1, the affinity constant (K M) showed a value of 55.7 (± 16.7) μM for a catalytic efficiency (k cat/K M) of 389 min-1 mM-1. GC-MS analysis showed that the only product from resveratrol transformation by cytochrome P450BM3 is the biologically active piceatannol. The enzymatic transformation of resveratrol, an emerging compound with medical interest, to active product piceatannol by a variant of cytochrome P450BM3 in the absence of expensive NADPH cofactor is demonstrated. This enzymatic process is economically attractive and can be scaled up to cover the increasing medical demand for piceatannol.