Development of a Purification Method to Obtain High-purity Pentacyclic Triterpenoids from Fruit Processing Residues.

Abstract

Pentacyclic triterpenoids present in peels that are discharged in large quantities during fruit processing, exhibit many potentially exploitable physiological activities. Because the structure of each triterpenoid is similar, it is difficult to isolate and purify individual molecules. We thus developed a simple method for the isolation and purification of pentacyclic triterpenoids. Liquid chromatography (LC) with a C30 column was used to determine an optimal mobile phase. In primary purification, water, methanol, and acetonitrile were assessed as mobile phases for the simultaneous purification of multiple components. In secondary purification, water and acetonitrile were used as mobile phases to achieve higher purity of the primary purified product. Pentacyclic triterpenoids were purified from dried apple processing residues using an established method, and euscaphic, annurcoic, and pomolic acids were simultaneously purified in the primary purification. Secondary purification of an annurcoic acid fraction yielded a highly purified product with a purity of 95.7% (HPLC). Purification was repeated and 10.15 mg of annurcoic acid was obtained from 85.79 g of dried apple processing residue. This established method can easily yield multiple pure pentacyclic triterpenoids using preparative LC. This method is thus expected to simplify sample preparation and contribute to the effective utilization of processing residues as source materials.