Preparation of Reference Standards of Glycyrrhizic Acid and Glycyrrhetic Acid
from Licorice

Bui Thi Chau Phuong, Pham Quynh Khoa, 
Nguyen Minh Cang, Nguyen Minh Duc*

*Corresponding author: ducng@hcm.vnn.vn

(Received September 7^th, 2013)

Summary

Preparation of Reference Standards of Glycyrrhizic Acid and Glycyrrhetic Acid
from Licorice

This study established a stable and repeatable method for extraction, isolation and purification of glycyrrhizic acid (GA) and glycyrrhetic acid (GH) from licorice to be used as reference standards. The method is applicable for large-scale production of these substances. The isolated substances were checked with various criteria for reference standards such as TLC unity and purity, melting point; UV-Vis , IR, MS, NMR spectra and quantitative analysis and passed all tests.

Keywords: Reference standard, Licorice, Glycyrrhizic acid, Glycyrrhetic acid.

1. Introduction

Licorice as well as its active substances such as GA have been used widely in traditional medicine, and in pharmaceutical and food industry. At the moment, licorice used in Vietnam is mostly imported from China with unidentified origin and quality. Therefore, to avoid the use of poorly qualified products, it is necessary to build up quality control methods for licorice and its products. Nowadays, there are many reliable quality control methods such as chromatographic methods, especially high performance liquid chromatography (HPLC). These methods often require reference standards to ensure accurate and reliable analytical results.

The aim of this study is to prepare the reference standards of GA and GH to serve research works, quality control and standardization of licorice and its products.