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

Figures & data

Fig. 1. Consecutive hydroxylation of resveratrol via piceatannol to PHS by HpaBC.

Fig. 2. Hydroxylation of resveratrol via piceatannol to PHS by E. coli cells expressing HpaBC.

Notes: The reaction time courses for resveratrol (open squares), piceatannol (open circles), and PHS (closed circles) concentration are shown. Data are the average of two independent experiments, and error bars indicate standard deviation of the mean.

Fig. 3. HPLC chromatograms of the reaction products formed from resveratrol by E. coli cells expressing HpaBC after 0.5 h (A) and 12 h (B).

Notes: Peaks 1 (at 6.2 min), 2 (at 5.8 min), and 3 (at 5.3 min) were found to correspond to resveratrol, piceatannol, and PHS, respectively.

Fig. 4. Effect of detergents on PHS production.

Notes: E. coli cells expressing HpaBC were incubated with 10 mM piceatannol in the presence of Tween 80 (circles) or Triton X-100 (triangles) for 6 h, and the concentration of the product PHS was determined. Data are the average of two independent experiments, and error bars indicate standard deviation of the mean.

Fig. 5. Effect of buffers on PHS production.

Notes: E. coli cells expressing HpaBC were incubated with 10 mM piceatannol in each buffer for 6 h, and the concentration of the product PHS was determined. Data are the average of two independent experiments, and error bars indicate standard deviation of the mean.

Fig. 6. Production of PHS on a flask scale.

Notes: E. coli cells expressing HpaBC were incubated with 10 mM piceatannol without (A) or with (B) pH adjustment. In (B), the pH of the reaction mixture was adjusted to 7.3 using 2 M NaOH at 8 and 24 h. The reaction time courses for piceatannol (open circles) and PHS (closed circles) concentration and pH (open triangles) are shown.