A new synthetic methodology for pyridinic sucrose esters and their antibacterial effects against Gram-positive and Gram-negative strains

摘要

Described are the development of a new synthetic method using ultrasonic irradiation and sodium methoxide as catalyst for a series of pyridinic sucrose esters (py-SEs), derived from transesterification of sucrose with picolinic, nicotinic and isonicotinic methyl esters. The reaction was optimized using a 3(2) x 2 experimental design, the reaction time, temperature and sucrose: methyl ester molar ratio being evaluated. The method proved to be efficient for obtaining monosubstituted esters (>= 83%) with high methyl ester consumption (>= 79%). The monosubstituted py-SEs were isolated by semipreparative HPLC, characterized by high-resolution mass spectrometry, calorimetry, vibrational spectroscopy, and H-1 and C-13 NMR. The py-SEs were tested against E. coli, S. aureos, and P. aeruginosa bacteria with minimum inhibitory concentration values equal or inferior to the reference drugs for both E. coli and P. aeruginosa.