Quality assessment of Typhae Pollen Carbonisata based on chromaticity analysis combined with UPLC fingerprinting and thrombin activity

Introduction: Typhae pollen (TP) has been used as an anticoagulant in traditional Chinese medicine and throughout Asia. Typhae Pollen Carbonisata (TPC), a processed product of TP, has hemostatic properties. TPC is produced by frying TP, and the degree of processing can be judged by the colour change from yellow to brown.

Objective: To establish a novel method for quality assessment of TPC and discriminate TPC from underdone products and overdone products.

Methodology: The Commission Internationale de l'Eclairage (CIE) L^* a^* b^* colour space values of TP and TPC were measured to establish the colour model of TPC. Ultra-performance liquid chromatography was developed for fingerprinting. Thrombin activity promoting rates, clotting time, and bleeding time illustrated the difference in the hemostatic effect of the processed products. Chemometric approaches were performed to reveal the correlation between components and colour values or thrombin activity.

Results: Reference ranges of colour values and mathematical functions of TPC were established. The developed method was found to be fast, economic, sensitive, and stable. Fingerprints and thrombin activity in conjunction with partial least squares (PLS) demonstrated that peaks 2, 4, 7, 30, and 36 (isorhamnetin) were the main contributors for colour values and hemostatic activity of TPC.

Conclusions: TPC and its unqualified products can be effectively distinguished based on chromaticity analysis, which provides a powerful tool for the comprehensive evaluation of the quality of Chinese herbal medicines.

Keywords: Typhae Pollen Carbonisata; chemometric analysis; colour value; quality control.