Fig. 4

HLADH-catalyzed oxidation lactonization of 1,4-BD in a two-liquid phase system (2LPS). Standard reaction conditions: NAD⁺ (0.1 mM), SBFC (0.05 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. a 1,4-BD (100 mM), and in different organic phase (5 mL), V_organic/V_aqueous = 5. Detection after 24 h. EtOAc ethyl acetate, DIPE diisopropyl ether, MTBE tert-butyl methyl ether. b At different substrate concentrations; organic phase: toluene (1 mL), V_organic/V_aqueous = 1. Detection after 48 h. Yields are average values of duplicates