Is 18α-Glycyrrhizin a real natural product? Improved preparation of 18α-Glycyrrhizin from 18β-Glycyrrhizin as a positive standard for HPLC analysis of licorice extracts

18α-Glycyrrhizin is an epimer of 18β-glycyrrhizin, a major component of licorice ( Glycyrrhiza sp.), which is widely used as a traditional medicine. Whether 18α-glycyrrhizin is a real natural product has been debated in the long history of glycyrrhizin chemistry because 18β-glycyrrhizin is epimeriza...

Full description

Saved in:
Bibliographic Details
Published in:Journal of natural medicines 2022-03, Vol.76 (2), p.367-378
Main Authors: Jitrangsri, Kritamorn, Kamata, Kazuaki, Akiba, Mana, Yajiri, Yoshie, Ishibashi, Masami, Tatsuzaki, Jin, Ishikawa, Tsutomu
Format: Article
Language:English
Subjects:
Biological Products
Biomedical and Life Sciences
Biomedicine
Chromatography, High Pressure Liquid - methods
Complementary & Alternative Medicine
Congeners
Esterification
Glycyrrhiza
Glycyrrhizic Acid
Glycyrrhizin
High-performance liquid chromatography
Medicinal Chemistry
Natural products
Original Paper
Pharmacology/Toxicology
Pharmacy
Plant Extracts
Plant Sciences
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:18α-Glycyrrhizin is an epimer of 18β-glycyrrhizin, a major component of licorice ( Glycyrrhiza sp.), which is widely used as a traditional medicine. Whether 18α-glycyrrhizin is a real natural product has been debated in the long history of glycyrrhizin chemistry because 18β-glycyrrhizin is epimerizable to a more thermodynamically stable 18α-glycyrrhizin under aqueous alkali conditions. We improved the preparation of 18α-glycyrrhizin from 18β-glycyrrhizin by successive epimerization reactions of 18β-glycyrrhizin, trimethyl esterification of the resulting epimerized mixture, and alkaline hydrolysis of a purified 18α-glycyrrhizin trimethyl ester. Approaches to the possible presence of 18α-glycyrrhizin in licorice extracts by HPLC using synthetic 18α-glycyrrhizin as a positive standard strongly suggested that 18α-glycyrrhizin could naturally exist as a minor congener of glycyrrhizin derivatives in Glycyrrhiza species. Graphical abstract
ISSN:1340-3443
1861-0293
DOI:10.1007/s11418-021-01589-9