Higenamine

S. acutum was purchased from Anhui FengyuanTongling Chinese Herbal Medicine Co., Ltd. (Anhui, China). Standards of higenamine, sinomenine, magnoflorine, tetrahydroberberine, tetrahydropalmatine, berberrubine, jatrorrhizine, columbamine, berberine, and palmatine were purchased from the Shanghai Yuanye Biological Technology Co., Ltd. (Shanghai, China). All aqueous solutions were prepared with bottled pure water (Wahaha, Hangzhou, China). High performance liquid chromatography grade acetonitrile and methanol were purchased from Fisher Scientific (Fair Lawn, NJ, USA). Other chemicals and solvents were all of analytical grade.

The standards of o-anisaldehyde (purity >96%), higenamine (purity >98%), and coryneine chloride (purity >98%) were purchased from Yuanye Biological Technology Co., Ltd (Shanghai, China). Salsolinol standard (purity >98%) was purchased from Tauto Biotech Co., Ltd (Shanghai, China). And cinnamic acid standard (purity >98%) was from Chinese National Institute for the Control of Pharmaceutical and Biological Products (Beijing, China). HPLC-grade acetonitrile and methanol were purchased from Tedia (Fairfield, USA). HPLC-grade phosphoric acid was supplied from Shanghai Aladdin Bio-Chem Technology Co., Ltd (Shanghai, China). Distilled water was used throughout the study.