Medicine, general, Health aspects, Analysis, Physiological aspects, Flowers & plants, CHEMISTRY, Medicinal plants, Environmental factor, Principal components analysis, Metabolism, Metabolites, Chromatography, Chinese medicine, UPLC-PDA, Quantitative analysis, Chemistry/Food Science, Rhubarb, Anthraquinone glycoside, Sennosides, Gastrointestinal agents, Botan...