| Grant number: | 17/09520-8 |
| Support Opportunities: | Scholarships in Brazil - Master |
| Start date: | January 01, 2018 |
| End date: | May 31, 2019 |
| Field of knowledge: | Physical Sciences and Mathematics - Chemistry - Organic Chemistry |
| Principal Investigator: | Mauricio Boscolo |
| Grantee: | Jorge Andrés Mora Vargas |
| Host Institution: | Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil |
Abstract The interest in sucrose derivatives has been increased due their different applications in various industrial sectors (pharmaceutical, cosmetic, bioengineering, chemistry, agriculture and food). One of the characteristics of sucrose is its behavior as a polyol, which allows synthesizing many value-added compounds, as well as being a low cost and environmentally friendly reagent. Sucrose esters are one of the possibilities of sugar derivatives with characteristics of non-ionic surfactants, emulsifiers, microbiological controllers, among others, and according to the nature of the acid group introduced into the sucrose molecule, may have different applications. On the other hand, pyridinic acids have been studied as antimicrobial agents, anticancer agents, dietary supplements, and thus are still unexplored. This study aims to synthesize pyridinic sucrose esters by transesterification reactions with homogeneous catalysis (sodium methoxide) with four pyridinic acids methyl esters (picolinic, nicotinic, isonicotinic and orotic) under ultrasound irradiation (20 kHz). Because of the polyactivity of sucrose, to control which and how many hydroxyls will undergo substitution is very difficult. In order to understand the factors governing the formation of the preferred regio-isomers derived from each pyridinic acid under different synthesis conditions, a factorial xn will be executed with the following three factors: (i) temperature (30 and 70 oC), (ii) The molar ratio of the starting ester to the sucrose (1: 1, 1: 2 and 1: 3); (Iii) reaction time (10, 20 and 30 min). In the conditions with the best synthesis yields, the influence of polyvalent metal ions (Cu2 +, Mn2 +, Fe3 +, Nb5 +) on the formation of regioisomers will also be tested. In this process the heterogeneous catalysis potential will also be studied by employing the solid Mg6Al2Ox as the catalyst. The products will be separated by preparative chromatography and the characterization will be done by refractive index, LC-ES-MS, ATR-FTIR, CHN and NMR, to observe the different degrees of esterification as well as the regioisomers, which should be tested for antimicrobial activity (two Gram + and two Gram -) by disc diffusion assay. (AU) | |
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