Atividade antimicrobiana de análogos da piperina

Abstract

The structural modification of natural compounds is of significant importance for medicinal chemistry, from 1981 to 2014 1328 medicines were approved for commercialization, of which 51.5% are of natural origin and 26.8% are derived from phytochemicals. An example is the natural amide piperine, which is the target of several biological investigations, and which has demonstrated the potential to act as a precursor to new compounds with application in the modulation of biological phenomena with the 1,2,4 oxadiazole nucleus, which are a class of heterocyclic that exhibit a range of biological activities and that can be used for the synthesis of potential microbial agents. This work aims to report the extraction of piperine by microwave. Reflux hydrolysis of piperine to obtain piperinic acid in moderate yields. Obtaining the ethyl piperininate esters and 3,4 methylenedioxy ethyl cinnamate with excellent yields. The synthesis of amidoximes using the conventional methodology of stirring with hydroxylamine hydrochloride, sodium carbonate and the corresponding nitriles with the substituents (p-nitro, p-toluyl, m-toluyl, benzo, piperonyl, 4-pyridine) in yields of 37% -98%. Using the methodology of synthesis of oxadiazole by microwave using ethyl cyano acetate esters with piperonylamidoxime, ethyl ester 3,4-methylenedioxy cinnamate with 4-pyridine and p-toluyl amidoxime in the presence of K2CO3 and DMF. All oxadiazol precursors were elucidated by IV and the 1,2,4-oxadiazoles synthesized characterized by 1H and 13C NMR. Some compounds were tested bactericidal activities, where the 1,2,4-oxadiazoles presented excellent results against Staphylococcus aureus and Klebsiella pneumoniae and one of the compounds presented luminescent activity a little reported in the 1,2,4 oxadiazoles.