Comparative Study on Two Antioxidant Flavanol-3-O-α-L- Rhamnosides in the Leaves of Toona sinensis (Chinese Toon) from Different Production Sites by HPLC-UV

Abstract

Two antioxidant flavonol glycosides, quercetin-3-O-α-L-rhamnoside (1) and kaempferol-3-O-α-L-rhamnoside (2), were isolated from the leaves of Toona sinensis by column liquid chromatography. For the first time, a convenient RP-HPLC-UV method for the simultaneous quantitation of these two glycosides was developed and validated for linearity, precision, accuracy, stability, and repeatability. This newly established method was used to compare the quantity and content ratio of these two rhamnosides present in the raw material harvested from different production sites. It was found that the content of 1 as well as the ratio of 1 to 2 in the material harvested from renowned regions is higher than the other. The data also revealed that rhamnoside 2 is lesser and thus supporting our previous hypothesis that besides the content of bioactive compounds, the content ratio is likely to be another crucial root cause leading to the difference in quality and health benefits of the natural product.

Keywords:

• Chinese Toon
• HPLC-UV
• kaempferol-3-O-α-L-rhamnoside
• quercetin-3-O-α-L-rhamnoside
• rhamnoside
• Toona sinensis Roemer