Salvianolic acid c

ER α, ER β, and buffer recombinant protein were purchased from Shanghai Tongwei Biotechnology Co., Ltd. (China). Ultrafiltration membranes (0.5 ml, 10 kDa) were purchased from Millipore Co., Ltd. (USA).
The MS-grade formic acid and acetonitrile were purchased from Thermo Fisher Scientific Co., Ltd. (USA). The ultra-pure water was obtained from Guangzhou Watsons Food & Beverage Co., Ltd. (China). Dimethyl sulfoxide (DMSO, W387520) was purchased from Sigma-Aldrich Chemical Co. (St. Louis, MO, USA). Other solvents were of analytical grade supplied by Aladdin Industrial Corporation. The chemical reference standards of malic acid, citric acid, caffeic acid, salvianolic acid B, rosmarinic acid, and salvianolic acid C were purchased from Chengdu Pufei De Biotech Co., Ltd. (China). Rutin, isoquercitrin, and quercetin were provided by Cheng Du Herbpurify Co., Ltd. (China). The purities of all the reference standards were above 98% according to HPLC-UV analysis.

MS grade formic acid and acetonitrile were purchased from Thermo Fisher Scientific Co., Ltd. (Waltham, MA, USA). Ultra-pure water was obtained from Guangzhou Watsons Food & Beverage Co., Ltd. (Guangzhou, China). Other solvents were of analytical grade and were supplied by the Aladdin Industrial Corporation (Shanghai, China). The chemical reference standards of shikonin, acetylshikonin, β,β-dimethylacrylshikonin, lithospermic acid, rosmarinic acid, salvianolic acid B, and salvianolic acid C were purchased from Chengdu Pufei De Biotech Co., Ltd. (Chengdu, China), while those of nicotiflorin, rutin, isoquercitrin, quercetin, hesperidin, naringenin, kaempferol, and baicalein were provided by Cheng Du Herbpurify Co., Ltd. (Chengdu, China). The purities of all reference standards were above 98% according to an HPLC-UV analysis. The brand and model of the sonication device was KQ-300DE from Kunshan Ultrasonic Instrument Co., Ltd. (Kunshan China).