2.1. Reagents
Herbal products with potential antivirus activity were obtained from Tianjiang Pharmaceutical Co., Ltd. (Jiangsu, China). Ammonium bicarbonate (NH4HCO3), dithiothreitol, and hydrochloric acid (HCl) were provided from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Urea was purchased from Dalian Meilun Biotechnology Co. Ltd. (Dalian, China). Iodoacetamide, chymotrypsin and trypsin were provided by Sigma-Aldrich (St. Louis, MO, USA). The peptide Dabcyl-KNSTLQSGLRK-Edans was synthesized from GenScript biology science and technology Co. Ltd. (Nanjing, China).