Study of the chemical variability of Brazilian propolis by mass spectrometry and the identification of compounds with antioxidant and antimicrobial activity

Abstract

Propolis is a resin used by bees for the protection of the hives, presenting a complex chemical composition which depends on the botanical ecology of each region. It is used by humanity since ancient times mainly due to its antiseptic and healing properties. Due to the ample diversity of native bees found in Brazil and the geographic and botanical variability, propolis with varied composition and therapeutic activity is found. One of the most frequently found species of native bees is the jataí (Tetragonisca angustula) which produces propolis with a similar composition throughout Brazil. There are few studies relation to the chemical composition, antimicrobial and antioxidant activity of these types of propolis. Among the types of propolis produced by the introduced bee species, Apis mellifera, we call attention to red propolis from the northeast of Brazil, which presents strong antioxidant and antimicrobial activity. The aim of this project is to study the chemical composition, antioxidant and antimicrobial activities of propolis produced by jataí and A. mellifera. The chemical composition will be initially evaluated by direct insertion mass spectrometry (fingerprinting) and then by ultra-high liquid chromatography-mass spectrometry (UHPLC-MS). The antioxidant activity will be evaluate using two different methods, DPPH and ORAC, and the antimicrobial activity will be evaluated against pathogenic Gram positive and negative bacteria and species of Candida. Propolis of other identified species of stingless bees may also be analyzed. The types of propolis that present promising activity will be fractioned by preparative chromatography and the activity of the fractions and isolated compounds will be revaluated. Finally the isolated active compounds will be analyzed by NMR, MS and IV to determine their structure. (AU)