Chemoenzymatic synthesis of phytosteryl ferulates and evaluation of their antioxidant activity.

The feasibility of a two-step chemoenzymatic synthesis of phytosteryl ferulates was successfully established in this work. An intermediate vinyl ferulate was first chemically produced and subsequently esterified with phytosterols through alcoholysis with Candida rugosa as a catalyst. The structures of phytosteryl ferulates were confirmed by Fourier transform infrared (FTIR) and high-performance chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS) using atmospheric pressure chemical ionization (APCI) under both positive and negative ion modes. The antioxidant activity of phytosteryl ferulates was higher than that of the starting material and the intermediate in the assays employed. The results indicated that phytosteryl ferulates had a good potential to be used as food antioxidants and may also serve as cholesterol-lowering agents.