Method development for the simultaneous quantification of orcinol glucoside and curculigoside in Curculigo orchioides by UPLC-PDA

Abstract

In Vietnam, the rhizomes of Curculigo orchioides have been traditionally used for the treatment of cough, impotence, cold uterus, etc. The phenolic compounds were determined as active constituents of C. orchioides; however, there is no quantitative criterion for these compounds in C. orchioides in the Vietnamese Pharmacopoeia. Therefore, this study aimed to develop a simultaneous quantification method for orcinol glucoside (OG) and curculigoside (CG) by UPLC-PDA system, required for the standardisation of C. orchioides rhizome. The simultaneous quantification of OG and CG was performed on the Acquity UPLC-PDA (Waters) system, InfinityLab Poroshell 120 CS-C18 (3,0×150 mm, 2.7 µm). The method was evaluated according to The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. The quantitative analysis of OG and CG met all validation requirements, including system suitability, specificity, linearity (R²>0.999), inter-day and intra-day precisions
(RSD<2.0%), accuracy with OG and CG recovery rate of 97.08-103.60 and 100.28-111.25, respectively. The contents of OG and CG in 6 samples of Rhizoma curculiginis collected in Son La, Lao Cai, and Dak Nong varied according to the growing region and harvest time with the yield of OG and CG 0.36-1.301 and 0.041-0.123%, respectively.