Background: To analyse the flavonoid components of Fructus Aurantii processed using the Zhangband method. Fructus Aurantii, the dried immature fruit of Citrus aurantium L., achieves its highest medicinal efficacy using the Zhangband method of processing, a specialized system of traditional Chinese medicine developed in Jiangxi Province, China. The flavonoids responsible for the medicinal qualities have never been analysed.
Methods: Fructus aurantii was processed according to traditional methods. Flavonoids were isolated by chromatography and identified spectrophotometrically.
Results: Four principal flavonoids were isolated: naringin (I), hesperindin (II), neohesperindin (III), and hesperetin 7-O-β-D-glucopyranoside (IV).
Conclusions: Hesperetin 7-O-β-D-glucopyranoside was newly identified in Fructus Aurantii; the compound was present in Fructus aurantii after, but not before, processing using the Zhangband method. Processing appears to attenuate the drying characteristics of Fructus aurantii and to enhance its medicinal efficacy.