Fig. 2

HLADH–SBFC-catalyzed oxidative lactonization of 1,4-BD. a Time-selectivity plots of HLADH-catalyzed oxidation of 1,4-BD. 1,4-BD (20 mM), NAD⁺ (0.5 mM), SBFC (0.1 mM), HLADH (0.3 g L⁻¹), and catalase (20 U/mL) in 1 mL of aqueous Tris–HCl buffer (50mM, pH 8.0) at 30 °C. b The results of reactions after 2 h, 4 h and 6 h detected by GC–MS. Peak A: 1,4-BD; Peak B: lactol; Peak C: butyrolactone