Preparation and Characterization of SHP

Paraformaldehyde was purchased from Tianjin Chemical Reagent Research Institute (Tianjin, China). PBS was purchased from Beijing Zhongshan Jinqiao Biotechnology Co., Ltd (Beijing, China). Ammonia was purchased from Hangzhou Changzheng Chemical Plant (Hangzhou, China). Hydrogen peroxide was purchased from Shanghai Yuanda Peroxide Co., Ltd (Shanghai, China). Methanol was purchased from Shanghai Zhenxing Chemical No. 1 Plant (Shanghai, China). Anhydrous ethanol was purchased from Hangzhou Chemical Reagent Co., Ltd (Hangzhou, China). Ethanol (95%) was purchased from Anhui Ante Biochemical Co., Ltd (Suzhou, China). SHP was previously prepared, and the chemical constituents were identified using UPLC-MS/MS [11 (link)].