Dynamic changes of flavonoids in Abelmoschus manihot different organs at different growth periods by UPLC MS/MS

Abelmoschus manihot (Linn.) Medicus has been clinically used to treat chronic kidney disease, oral ulcers, bums, and dysmenorrhea in China for many centuries. The major pharmacologically-active components of A. manihot are flavonoids. In this study, a rapid and highly sensitive UPLC-MS/MS analysis method was established and successfully applied to the simultaneous determination of five major flavonoids (rutin, hyperoside, isoquercitrin, quercetin, and myricetin) in different parts of A. manihot harvested at ten growth periods. Under the optimized chromatographic conditions, good separation for five target components was obtained on an Acquity UPLC BEH C18 column within 18 min. The total contents of the five investigated flavonoids in A. manihot roots, stems, leaves and flowers ranged from 2.86 to 123.7 mu g/g, 46.39 to 141.0 mu g/g, 929.4 to 3096 mu g/g, and 10,150 to 19,390 mu g/g, respectively, indicating that the total flavonoids in the four parts could be mainly arranged in a decreasing order as flower > leaf > stem > root. The peak of total flavonoids in flowers and leaves appeared at G8 and G9, respectively. These results will be helpful for the determination of the suitable harvest time of A. manihot and the improvement of the utility value of the disused parts.