In a previous work developed on our research group, the phytochemical study of the roots of young plants of Maytenus ilicifolia (Celastraceae), associated with the evaluation of biological activity, led to the isolation of quinonemethide triterpenes with potent antioxidant, antifungal, antitumor and trypanocidal activities, being maytenin and pristimerin the most active compounds. Phytochemical studies comparing young and adult plants of M. ilicifolia also indicated that the quinonemethide triterpenes are accumulated exclusively in young plants, while adult specimens produce sesquiterpene pyridine alkaloids. As part of our on-going program devoted to studying secondary metabolite biosynthesis within Celastraceae family a study was conducted to investigate quinonemethide triterpenes cyclization using 2,3- epoxysqualene as a precursor and enzyme extracts from the bark of the roots, leaves and twigs of young plants of M. ilicifolia. This study allowed us to obtain vast knowledge about the conditions of extraction, analysis, characterization and compartmentalization of the cyclase enzyme, which was reported as the first biosynthetic study of this class of compounds described in the literature. Quinonemethide triterpenes have some interesting chemical / biological features including the fact that their oxidation pattern at the E ring differs from that of a regular triterpene skeleton. Moreover, the different substituents at the E ring are considered as pharmacophoric groups, which are responsible for the observed biological activity. Studies carried out to determine the activity of the cytochrome P450 oxidoreductase type enzyme in the roots of M. ilicifolia indicated that this class of enzymes may mediate the oxidation steps that occur in the quinonemethide E ring. Therefore, this project aims to study the oxidoreductase-type enzyme cytochrome P 450 in M. ilicifolia. The analysis will focus on the use of young and adult plant specimens in order to facilitate a comparison of the total proteome in different stages of development and the identification of the type of cytochrome P 450 enzyme that is active in young plant extracts. This study will also help to establish a parallel between the pathways involved in the biosynthesis of quinonemethides and sesquiterpene pyridine alkaloids. The enzyme extract obtained will be pre-purified and analyzed by techniques of two-dimensional gel electrophoresis (SDS-PAGE) and mass spectrometry (MALDI-TOF or Q-ToF).
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