Isolation and identification carpaine in carica papaya L. Leaf by HPLC-UV method

Abstract

The carpaine was isolated from Carica papaya L. leaf, was identified by means of Fourier transform infrared spectroscopy, mass spectrometry, nuclear magnetic resonance, and was determined by HPLC. The powder of dried leaves was macerated and extracted with ethanol/water/HCl (89:10:1 V/V/V) to produce crude alkaloid. The extract was fractionated on a silica gel column chromatography using methanol/chloroform (5:95 v/v) as the eluate. The major fraction was isolated according to Rf values of thin-layer chromatography (TLC) (silica gel, methanol/chloroform [15:85 v/v]) exposed by Dragendroffs reagent. The extraction procedure, sample preparation, and HPLC conditions were evaluated and optimized. The method was fully validated in terms of accuracy, precision, specificity, and calibration model. Results showed that the developed HPLC method was suitable for the determination of carpaine using a single-point calibration. The calibration model was linear in the concentration range from 0.20 to 1.8 mg/mL. Analysis of different days showed that the method was precise with an average concentration of 0.93 g/kg and relative standard deviation of 0.062%. A recovery of between 97.6 and 100.1% was obtained in a 95% confidence interval indicating that the method was accurate and the content of the carpaine in the powdered Carica papaya leaves was 0.93 g/kg.