Determination of dextranase activity using 3-methyl-2-benzothiazolinone hydrazone method: Substrate refinement and fast-dissolution, method development and validation.

A highly sensitive method has been developed for accurately measuring dextranase activity using 3-methyl-2-benzothiazolinone hydrazine. This method is based on the dextran refinement and fast-dissolving approach established in this study, as well as the assay method for enzymatic hydrolysates. The measurement parameters for the reducing sugar ends were optimized by examining the slope, intercept, R, and time stability of the standard curve of glucose solutions containing dextran. Kinetic determination was utilized to optimize enzymatic parameters and validate the method, which was subsequently utilized for the analysis of toothpaste and mouthwash. The findings suggest that the enzymatic hydrolysis follows a zero-order reaction, laying a solid foundation for the end-point assay of dextranase activity. The results demonstrated a linear correlation within the measurement range (0.7-6.5 mU/mL), exhibiting good repeatability, high sensitivity and accuracy. This method outperformed the 3,5-dinitrosalicylic acid method and circumvented potential interference from other components in toothpaste and mouthwash.