Biocatalytic synthesis of 3,4,5,3′,5′-pentahydroxy-trans-stilbene from piceatannol by two-component flavin-dependent monooxygenase HpaBC

Abstract

HpaBC monooxygenase was previously reported to hydroxylate resveratrol to piceatannol. In this article, we report a novel catalytic activity of HpaBC for the synthesis of a pentahydroxylated stilbene. When Escherichia coli cells expressing HpaBC were incubated with resveratrol, the resulting piceatannol was further converted to a new product. This product was identified by mass spectrometry and NMR spectroscopy as a 5-hydroxylated piceatannol, 3,4,5,3',5'-pentahydroxy-trans-stilbene (PHS), which is a reportedly valuable biologically active stilbene derivative. We attempted to produce PHS from piceatannol on a flask scale. After examining the effects of detergents and buffers on PHS production, E. coli cells expressing HpaBC efficiently hydroxylated piceatannol to PHS in a reaction mixture containing 1.5% (v/v) Tween 80 and 100 mM 3-morpholinopropanesulfonic acid-NaOH buffer at pH 7.5. Under the optimized conditions, the whole cells regioselectively hydroxylated piceatannol, and the production of PHS reached 6.9 mM (1.8 g L(-1)) in 48 h.

Short-step syntheses of naturally occurring polyoxygenated aromatics based on site-selective transformation

“…The corresponding aglycon, piceatannol (2b), was synthesized from resveratrol (4b) by biochemical hydroxylation at the C-3′ position (Scheme 3). 37,38) The partially acetylated form 2c was also prepared from 4c by chemical oxidation. 39) In the latter case with 2-iodoxybenzoic acid (IBX)mediated oxidation, a free hydroxy group at C-4′ is necessary, and others at C-3 and C-5 should be protected.…”

Biosynthesis of eriodictyol from tyrosine by Corynebacterium glutamicum

“…The enzyme complex HpaBC generally has a great demand for oxygen in the hydroxylation reaction [ 20 ]. However, we found that eriodictyol production was not linearly correlated with the culture volume, which is an indirect measure of oxygen supply.…”

Oxygenating Biocatalysts for Hydroxyl Functionalisation in Drug Discovery and Development

“…Kino et al have demonstrated that two-component FMO HpaBC could not only selectively hydroxylate chemically-complex resveratrol, [185] but also the hydroxylated-product, piceatannol. [186] The latter reaction afford 3,4,5,3',5'-pentahydroxy-trans-stilbene (PHS), a biologically-active stilbene derivative in 1.8 g L À 1 product titre, and represented the first example of this enzymatic hydroxylation. [186] Hong et al also studied the regioselective hydroxylation of stilbene compounds but with a different FMO, Sam5.…”

“…[186] The latter reaction afford 3,4,5,3',5'-pentahydroxy-trans-stilbene (PHS), a biologically-active stilbene derivative in 1.8 g L À 1 product titre, and represented the first example of this enzymatic hydroxylation. [186] Hong et al also studied the regioselective hydroxylation of stilbene compounds but with a different FMO, Sam5. [187] The group studied Sam5 3'-hydroxylase activities on a series of methylated-resveratrol analogues (pinostilbene and pterostilbene) and hydroxylated-resveratrol (oxyresveratrol), which produced the 3'-hydroxylated products in 37-54 % conversions.…”