Effect of enzymolysis after acid and alkali pretreatment on extraction of tanshinones from Salviae Miltiorrhizae Radix et Rhizoma residues

Abstract

Salviae Miltiorrhizae Radix et Rhizoma residues were pre-treated with acid and alkali, degraded by using cellulose, and the effects of different processing methods on the extraction rate of tanshinones were compared to provide scientific basis for development and utilization of tanshinones from Salviae Miltiorrhizae Radix et Rhizoma residues. The results showed that in the Salviae Miltiorrhizae Radix et Rhizoma residues without pre-treatment, enzymatic hydrolysis time of 4.5 d could make most of the cellulose degraded when the concentration of substrate enzyme concentration was 6 U•mL-1, and the highest glucose concentration was 59.74 mg•g⁻¹. It was found that the best effect was achieved after alkali pre-treatment-cellulose C degradation among the different pre-treatment methods, and the glucose content reached 119.50 mg•g⁻¹, followed by the same concentration of acid pre-treatment-cellulose C degradation. The extraction amount of tanshinone ⅡA was increased by 82.54% after enzyme degradation, with a mass fraction of 2.451 mg•g⁻¹; extraction amount of tanshinone I was increased by 81.82% after enzyme degradation, with a mass fraction of 2.373 mg•g⁻¹; extraction amount of cryptotanshinone was increased by 64.4% after enzyme degradation, with a mass fraction of 1.080 mg•g⁻¹; extraction amount of dihydrotanshinone I was increased by 61.3% after enzyme degradation, with a mass fraction of 0.601 2 mg•g⁻¹. Acid and alkali pre-treatment combined with cellulose degradation could effectively improve the extraction rate of tanshinones from Salviae Miltiorrhizae Radix et Rhizoma residues. This method is operable and practical, and it is beneficial for improving the utilization efficiency of tanshinones (resource based chemicals) from Salviae Miltiorrhizae Radix et Rhizoma residues.