[Quality evaluation of Galli Gigerii Endothelium Corneum based on HPLC fingerprints and content determination of nucleosides].

Galli Gigerii Endothelium Corneum(GGEC), the dried gizzard membrane of Gallus gallus domesticus is a Chinese medicinal material commonly used for digestion. However, due to the particularity of texture and composition, its active ingre-dients have not been clarified so far, and there is also a lack of quality evaluation indicators. In this study, UPLC-Q-TOF-MS was used to analyze the chemical components from the water extract of GGEC, and ten nucleosides were identified for the first time. HPLC fingerprints of the water extracts of GGEC were established and the content of seven nucleosides was determined. The fingerprint similarities of 40 batches of GGEC samples ranged from 0.765 to 0.959, indicating that there were great differences among the GGEC products processed with different methods. In addition, SPSS 22.0 and SIMCA 14.1 were used for hierarchical cluster analysis(HCA) and principal component analysis(PCA) on the 19 common peaks of the HPLC fingerprints of GGEC, and the 40 batches of samples were divided into three categories: raw GGEC, fried GGEC and vinegar-processed GGEC. Eight differential components in GGEC were marked by orthogonal partial least squares discrimination analysis(OPLS-DA), two of which were adenine and thymine. The results of content determination showed that the total content of the seven nucleosides in raw GGEC, fried GGEC and vinegar-processed GGEC were 182.5-416.8, 205.3-368.7, and 194.2-283.0 µg·g~(-1), respectively. There were significant differences in the content of hypoxanthine, thymine and thymidine among the GGEC products processed with different methods(P<0.05), which were graded in the order of fried GGEC>vinegar-processed GGEC>raw GGEC. This suggested that the content of hypoxanthine, thymine and thymidine tended to increase during the frying process, and the variation range might be related to the degree of heat exposure. The established methods in this study were simple and reproducible, and could be used for qualitative and quantitative analysis of GGEC and its processed pro-ducts. This study also provided reference for the establishment of quality standards of GGEC with chemical components as control index.