Chelerythrine

The isoquinoline alkaloids and phenolic compounds identification and quantification of C. solida and P. lutea were performed using liquid chromatography equipped with electrospray ionization-tandem mass spectrometry with a triple quadrupole analyzer.
Reference substances such as protopine, berberine, sanguinarine, chelidonine, chelerythrine were purchased from Extrasynthese (Genay, France); allocryptopine, coptisine, malic acid, t-aconitic acid, quinic acid, caffeic acid, chlorogenic acid, p-coumaric acid, vanillin, rutin, and quercetin were purchased from Sigma-Aldrich (St. Louis, MO, USA).

Water, LC–MS-grade methanol, and eluent-additive LC–MS ultra-ammonium formate (NH₄HCO₂) were purchased from Fluka Analytical (St. Louis, MO, USA).
Alkaloid standards such as chelidonine (purity ≥ 95%), sanguinarine (purity ≥ 90%), chelerythrine (purity ≥ 90%), and berberine (purity ≥ 95%) were purchased from Extrasynthese (France). Coptisine (purity ≥ 98%), p-coumaric acid, tannic acid, salicylic acid, chlorogenic acid, vanillic acid, trans-caffeic acid, vanillin, rosmarinic acid, quinine sulfate, and quercetin were purchased from Sigma (St. Louis, MO, USA).
Water was deionized and purified by ULTRAPURE Millipore Direct-QVR 3UV-R (Merck, Darmstadt, Germany).

Alkaloid standards such as protopine (purity ≥ 95), berberine (purity ≥ 95%), chelidonine (purity ≥ 95%), chelerythrine (purity ≥ 90%), and sanguinarine (purity ≥ 90%) were purchased from Extrasynthese (France) and allocryptopine, (purity ≥ 95), coptisine (purity ≥ 98%) from Sigma (St. Louis, MO, USA). Ammonium acetate, acetic acid, HPLC grade methanol (MeOH), and acetonitrile (ACN) were from Merck (Darmstadt, Germany). Water was deionized and purified by ULTRAPURE Millipore Direct-QVR 3UV-R (Merck, Darmstadt, Germany).
Alkaloid mixtures used for bioactivity assays were obtained from the following sources:
sanguinarine (Sang), chelerythrine (Cheler) were isolated as a mixture from Coptis chinensis rhizoma (19g/100g yield). Three mixures were used: Sang-Cheler (0.2:1 w/w); Sang-Cheler-Chelid (0.2:1:1, w/w); Sang-Cheler-Berb (0.2:1:1, w/w).