Chapter 13 - Analysis of pentaterpenoids

Abstract

Triterpenes are the most representative group of phytochemicals, with over 30,000 compounds being known to exist. These compounds are composed of six C5 isoprene units and are biosynthesized via the cyclization of squalene. They have been found to possess several pharmacological properties such as anticancer, anti-HIV, and antiinflammatory actions. Interestingly, plants containing substantial levels of pentacyclic triterpenes have been used in folk medicine in many parts of the world since ancient times. The average daily consumption of pentacyclic triterpenes has been estimated to be around 250mg which is higher than that in the Mediterranean diet. Most of the pentacyclic triterpenes found in fruits such as oleanolic acid and ursolic acid are distributed within the skin and cuticular wax. Therefore, there is substantial loss of these compounds if the fruits have their skin removed during processing. Extraction of these compounds can be achieved through the use of different techniques, including conventional methods such as Soxhlet and shaking extraction and newer methods such as microwave-assisted extraction and supercritical fluid extraction. Future trends of analysis are also being reviewed such as high-speed countercurrent chromatography. New developments have been made to this analysis such as cross-axis countercurrent chromatography, foam countercurrent chromatography, dual countercurrent chromatography, and pH-zone-refining countercurrent chromatography.