Fotodegradação da sinefrina: estudos experimentais e teóricos

Abstract

Obesity represents a serious public health problem, coupled with social culture that impose certain beauty standards, associated with thinness, leads to an unbridled search for "natural" formulations that present weight loss or supposedly weight loss substances. In this context, we can highlight the synephrine, found in the Citrus aurantium L. fruit peel extract, which has been widely used for this purpose. The risk lies in the fact that most of the time these compounds have no scientific support for their efficacy and safety. Recent studies report the synephrine instability when exposed to ultraviolet light, forming degradation products. Toxicological studies have shown that photodegraded synephrine has cytotoxic potential, probably due to the presence of the formed products. The present work aims to develop a method by LC-ESI-MS and an in silico study to identify the main photodegradation products, as well as their degradation routes. The LC-ESI-MS method was developed following parameters such as: column C18 (250 x 4.6 mm, 5μm), mobile phase composed of methanol:water (50:50, v/v), flow rate of 0.4 mL min-1, capillary voltage 2.5 kV, source temperature 110° C, desolvation temperature 250° C, desolvation nitrogen flow 900L h -1 , cone nitrogen flow 90L h -1 and analysis spectrum between m/z 50-900. The in silico study was carried out according to computational methodology taking into account the calculation of hydrogen atoms abstraction of the synephrine chemical structure in the photolytic degradation. MS analysis and the in silico study results suggest the formation of the product 1methyl-2,3- dihydro-1H-indole-3,6-diol, due to the higher reactivity of the side chain amino group of the molecule, with formation of the amino-chroman group. The obtained data collaborate with the studies in the area and can be used to aid in the identification and determination of the synephrine degradation routes.