Pharmacognostic specification and quercitrin content of dendrophthoe pentandra leaves

Abstract

Dendrophthoe pentandra leaf has been used in traditional Thai medicine as aqueous adjuvant and also used to treat diuretic and hypertension. This study expected to establish the pharmacognostic specification and analyse the chemical complement, quercitrin by thin layer chromatographic densitometry and thin layer chromatographic image analysis. The crude drugs were collected from 13 different locations throughout Thailand. The macroscopic characteristics were shown dried leaves, ovate and elliptic shapes, thickly leaves, green and brown colors and different sizes. Anatomical and histological characteristics demonstrated epidermis, paracitic typed stomata and unicellular trichome. The total ash, acid insoluble ash, loss on drying and water content should be not more than 11.94±0.19, 4.17±0.88, 9.16±0.61 and 9.99±0.70 w/w respectively. Ethanol extractive value and water extractive value should be not less than 7.67±3.48 and 22.24±5.50 w/w respectively. Thin layer chromatographic fingerprint of ethanolic extracts of the leaves was developed using ethyl acetate: formic acid: acetic acid: H2O (13: 1: 1: 2.5) as mobile phase. Detection under daylight, ultraviolet light (254 and 366 nm) and dipping with ferric (III) chloride reagent indicated the apparent band at hRf 73.5%. Quantitative analysis of quercitrin was performed by TLC densitometry. Linearity range of quercitrin was 0.25-1.0 mg with correlation (r2) of 0.998. LOD and LOQ were 0.16 and 0.49 mg respectively. The precision determined by the % RSD of repeatability and intermediate precision, were between 2.46-4.30 % RSD and 5.99-7.39% RSD respectively. The recoveries were 96.41-100.97% recoveries. Quantitative analysis of quercitrin was performed by TLC image analysis. Linearity range of quercitrin was 0.25-1.0 mg with correlation (r2) of 0.995. LOD and LOQ were 0.16 and 0.50 mg respectively. The precision determined by the % RSD of repeatability and intermediate precision, were between 3.24- 6.14 % RSD and 4.05-9.02 % RSD respectively. The recoveries were 81.57-103.09 % recoveries. The comparison between TLC densitometric and TLC image analysis of quercitrin content in D. pentandra leaves was performed by paired t-test. The averages of quercitrin content by TLC densitometry and TLC analysis using imageJ were 3.71±1.33 g/100 g and 3.89±0.97 g/100 g respectively. The comparison was found that the quercitrin contents by two methods were not significantly different (P > 0.05).This result can be used as specification for quality control and standardization of D. pentandra leaves in Thailand