Milli q purifying system

Reference compounds of the sixteen chemicals of liquiritin apioside (1) and isoliquiritin apioside (4) were purchased from Nanjing Jingzhu Bio-technology Co., Ltd. (Nanjing, PR China); neoliquiritin (2), ononin (6), licochalcone B (8), isoliquiritigenin (11), glycyrrhizin (12), formononetin (13), and licoflavone A (14) were acquired from Chengdu Chroma-Biotechnology Co., Ltd. (Chengdu, PR China); liquiritin (3), liquiritigenin (9), echinatin (10), licochalcone A (15), and glycyrrhetinic acid (16) were obtained from Liangwei Chemical Reagent Co., Ltd. (Nanjing, PR China); isoliquiritin (5) and neoisoliquiritin (7) were offered by Chengdu Purechem-Standard Co., Ltd. (Chengdu, PR China). The purities of all chemical standards were greater than 98% by HPLC analysis. Ultra-pure water was prepared by a Milli-Q purifying system (Millipore, Bedford, MA, USA). Methanol and acetonitrile of HPLC grade were purchased from Merck (Damstadt, Germany). All other chemicals used in the experiments were of analytical reagent grade (Shanghai Yuanye-Biotechnology Co., Ltd., PR China).

Ultrapure water was prepared using a Milli-Q purifying system (Millipore, Bedford, MA, USA). Methanol and acetonitrile of HPLC grade were purchased from Merck (Damstadt, Germany). Standard compounds of histidine (1), arginine (3), cysteine (4), asparagine (5), serine (6), lysine (7), glutamine (8), proline (9), cytidine (10), hypoxanthine (11), deoxycytidine (12), uridine (13), tyrosine (14), guanine (15), guanosine(16), inosine(17), deoxyguanosine (19), isoleucine (20), leucine (21), thymidine (23), phenylalanine (24), tryptophan (27), epicatechin (33), rutin (34), hyperoside (35), and quercitrin (37) were purchased from Shanghai Yuanye Biotechnology (Shanghai, China); glutamic acid (2), gallic acid (22) and apigenin (43) were obtained from Chinese National Institute of Control of Pharmaceutical and Biological Products (Beijing, China); fumaric acid (18), gallocatechin (25), epigallocatechin (28), cryptochlorogenic acid (31), kaempferol 3-O-rutinoside (39) and amentoflavone (42) were acquired from Chengdu Chroma Biotechnology (Chengdu, China); neochlorogenic acid (26), chlorogenic acid (29), catechin (30), caffeic acid (32), isoquercitrin (36), avicularin (38), trifolin (40), and astragalin (41) were bought from Baoji Chenguang Biotechnology Co., LTD. (Baoji, China) with the purity greater than 98% and their structures were presented in Figure S4.

Methanol and acetonitrile of HPLC grade were purchased from Merck (Damstadt, Germany); ultrapure water was prepared using a Milli-Q purifying system (Millipore, Bedford, MA, USA); standard compounds of chlorogenic acid, cryptochlorogenic acid, neochlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, ferulic acid, caffeic acid, loganin, proline, alanine, serine, leucine, lysine, histidine, arginine, cytidine, uridine, adenosine, and phenylalanine were obtained from Shanghai Yuanye Biotechnology Co. Ltd (Shanghai, China); 1,3‐O‐dicaffeoylquinic acid, isochlorogenic acid C, protocatechuic acid were purchased from Chengdu Prefa Technology Development Co. Ltd (Sichuan, China); quinic acid, rutin, hyperoside, astragalin, isoquercitrin were acquired by the Control of Pharmaceutical and Biological Products (Beijing, China); diosmetin, apigenin, kaempferol, kaempferol‐3‐O-rutinoside, sweroside were purchased from Chengdu Chroma Biotechnology Co. Ltd (Sichuan, China); 4,5‐O-dicaffeoylquinic acid methyl ester, luteolin, luteoloside, rhoifolin, lonicerin, secologanic acid, loganin acid, morroniside were provided by Liangwei Chemical Reagent Co. Ltd (Nanjing, China); secoxyloganin were taken from Nanjing Jingzhu Biotechnology Co. Ltd (Nanjing, China). The purity of all standard compounds was more than 98%.