Lupane-Type Triterpenoids Biotransformation

Abstract

A lot of scientific material has been accumulated in recent years about the biotransformation processes of lupine-type triterpenoids. The novelty of this review is the summary of these works, the analysis and identification of the most suitable biocatalysts for future researchers, and the presentation of development trends for new derivatives. The known biotransformation examples of the most common lupine-type triterpenoid representatives are considered. Analysis of their biosynthesis pathways starting with squalene is included also. Various approaches in this study are discussed to biotransformation using fungi, bacteria, and plant cell cultures. The conversion of betulin to betulinic acid is a process of special, even extreme interest. Cytochromes P450 are responsible for the catalysis of oxidation reactions while air oxygen is the oxidizer. The expression and activity of these enzymes are crucial factors for product yield. Basically, any given lupine-type triterpenoid can be transformed with P450 monooxygenases. Sadly, P450 catalysts are heme and NAD (P) H-dependent thus using isolated enzymes is not an option for biotransformation. So the whole-cell catalytic processes are completed by the formation of acids, ketones, or other oxidized products. Fungi cell cultures especially Cunninghamella blakesleeana, Armillaria luteo-virens, and Rhodotorula mucilaginosa are characterized by one of the highest conversion rates. Also, fungi cells are tolerant to the antibacterial activity of lupinetype triterpenoids. Thus fungi are the most successful biocatalysts for biotransformation. Applications of lupane-type triterpenoids such as pro-drugs and cosmetics are addressed in the final part of this study. It has clearly indicated development prospects for obtaining new useful derivatives.