Aplicação da Amberlyst-15 na reação de Per-O-acetilação do 1,2:3,4-di-isopropilideno-d-galactopiranose e estudo in silico.

Abstract

Carbohydrates belong to the most abundant group of compounds found in natural sources, and several studies indicate the diversity of biological applications of these biomolecules. Specifically, the per-O-acetylation reaction is an important structural change from the point of view of carbohydrate chemistry, however, there are still many limitations in this transformation. An alternative to such limitations is the use of heterogeneous catalysts. Thus, this work proposes the development of a new method for the per-O-acetylation reaction of 1,2: 3,4-di-O-isopropylidene-α-D-galactopyranose through heterogeneous catalysis using amberlyst-15 . Initially, 1,2: 3,4-di-O-isopropylidene-α-D-galactopyranose was synthesized from D-galactose in an acidic medium according to the Shmidt protocol. Then, several reactions were carried out in order to optimize the method by evaluating different parameters such as energy employed, temperature and amberlyst-15 amount. The best method obtained was using 150% amberlyst-15 in a heated ultrasonic bath, since it led to 6-O-acetyl-1,2: 3,4- diisopropylidene-α-D-galactopyranose with 94% yield after 60 minutes of reaction. The use of amberlyst-15 in the reactions was effective even in minimal amounts, but an increase in reaction time was observed. The method proved to be efficient, simple and fast when compared to other methods using homogeneous catalysts. Amberlyst-15 was easily removed from the reaction medium by filtration and could be reused for four cycles, without significant loss of its catalytic activity. In silico methods pointed out that 6-O-acetyl-1,2: 3,4- diisopropylidene-α-D-galactopyranose possibly has a low probability of having toxic effects, good characteristics for becoming a good drug. , an excellent potential for oral bioavailability, and the probability of performing different functions through different pharmacological mechanisms.