| With Candida sp.99-125 lipase as a catalyst and n-caprylic acid as an acyl donor,β-sitosterol caprylate was synthesized.The synthesized product was characterized by thin layer chromatography, nuclear magnetic resonance analysis, differential scanning calorimetry, high performance liquid chromatography. In addition, the influences of solvent type, dosage of lipase, reaction temperature, substrate molar ratio, substrate concentration and reaction time on conversion rate were studied by single factor experiment.The results showed that synthesized product was identified as β-sitosterol caprylate, and the melting point of β-sitosterol decreased significantly after esterification with n-caprylic acid, which was helpful to broaden the application range of phytosterol. The conversion rate could reach above 90% under the conditions of 20 mg/mL Candida sp.99-125 lipase, 5 mL isooctane, 50 mmol/L β-sitosterol, molar ratio of β-sitosterol to n-caprylic acid 1∶ 1, 120 mg/mL 3 molecular sieves, reaction at 45 ℃ for 12 h. |
