The determination of the total flavonoids by UV and a flavone glycoside by HPLC in Torreya grandis Fort Leaves

Abstract

A UV method was established to determination the total flavonoids in extractive solution from Torreya grandis Fort, leaves, and a RP-HPLC method was developed and validated to quantify 4', 5, 7-Trihydroxyflavone- 5- O- [alpha- L- Rhamno-pyranosyl- (1rarr4)- 6- O- acetyl- beta- D- glucopyranoside] (FRG). The dried leaf samples were extracted using methanol. The extracts were directly analyzed, without any purification, on a reversed-phase ODS column (250 mm times 4.6 mm, 5mum) with acetonitrile-phosphate aqueous (pH 3.8) isocratic elution and the detection was carried out by UV at 330 nm. The UV method showed excellent linearity, precision and accuracy. The standard curve for total flavonoids was linear over the range of 4-18 mug-m-1 (R2 = 0.9995). The HPLC method was validated for linearity, precision, accuracy, limit of detection and quantification. The standard curve for FRG was linear over the range of 0.39 mug - 3.53 mug (R2 = 0.9998). This method showed excellent repeatability (relative standard deviation, R.S.D. < 2.0%), precision(R.S.D. = 1.4%) and accuracy(102.27; R.S.D. = 1.02%). The limits of detection (LOD) of FRG, based on a detector signal-to-noise ratio of 3, were 0.065 mg ml-1 and the lowest levels tested in Torreya grandis Fort, leaves by this procedure (limit of quantification, LOQ) were 0.196 mg m-1.This assay can be readily utilized as quality controlled method for Torreya grandis Fort preparations.