Chemical characterization, cytotoxicity, antimicrobial and antioxidant potential of Justicia pectoralis Jacq and Croton jacobinensis Baill extracts

Abstract In this research, aqueous and ethanolic extracts from Justicia pectoralis Jacq and Croton Jacobinensis Baill were characterized. The UPLC-QTOF-MSE analysis was performed on the extracts identified, predominantly, flavonoids, tannins and acids. The extracts did not indicate toxicity in human epithelial cells. C. jacobinensis presented a concentration of phenolics 60.5% higher than J. pectoralis in all scenarios evaluated and, for both samples, the hydroalcoholic extract at 70% exhibited the best efficiency in the extraction (14501.3 and 32521.5 mg GAE 100 g-1 for J. pectoralis and C. jacobinensis, respectively). The antioxidant activity presented a positive correlation with the concentration of phenolics, being 1.186,1 and 1.507,9 µM of Trolox for J. pectoralis and C. jacobinensis at 70% of ethanol; however, it was not verified statistical difference between the ethanolic solutions (p < 0.05). The antimicrobial activity of J. pectoralis extracts was highlighted once was the most effective against gram-positive bacteria. The results suggest that both J. pectoralis and C. jacobinensis extracts present the potential to be applied as natural additives due to their antioxidant and antimicrobial activity and safety. Thus, it is suggesting the development of studies that could investigate the interaction of these plant extracts with food matrices is required

Antimicrobial activity and chemical characterization of the bark decoction of cumaru stem / Atividade antimicrobiana e caracterização química do decocto da casca do caule de cumaru

ABSTRACT: The plant, Amburana cearensis A. C. Smith (Fabaceae), commonly called cumaru, is widespread in the Caatinga cearense, a less known ecosystem in Brazil. A. cearensis is rich in several compounds like protocatechuic acid, tannins, coumarin, flavonoids and phenolic heterosides, such as amburosides A and B, that have been isolated. The aim of this study was to determine the antimicrobial potential and draw the chemical profile of the distinct characteristics of A. cearensis stem bark decoction, for its possible potential as a food conservation agent. The chemical compounds were characterized by one- and two-dimensional 1H and 13C NMR analyses and Liquid Chromatography-Mass Spectrometry (LCMS). The compounds of coumarin, amburosides A and B, and glycosylated (Z)-o-coumaric acid. Using the plaque microdilution technique, the antimicrobial action was tested on Escherichia coli, Salmonella Enteritidis, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. The decoction demonstrated antimicrobial activity on Gram-positive bacteria. This was encouraging because natural antimicrobials are beneficial for food production, as they can inhibit the pathogenic microorganisms and boost the quality of hygiene and cleanliness.

RESUMO: Amburana cearensis A. C. Smith (Fabaceae) é uma planta comum na Caatinga cearense, onde é popularmente conhecida como cumaru. Vários compostos têm sido isolados de A. cearensis, incluindo ácido protocatecúico, taninos, cumarina, flavonóides e heterosídeos fenólicos, como por exemplo os amburosídeos A e B. O objetivo desse estudo foi avaliar o potencial antimicrobiano e caracterizar o perfil químico do decocto da casca do caule de A. cearensis, visando a sua possível utilização na conservação de alimentos. A caracterização dos compostos químicos foi realizada pelas análises de RMN uni e bidimensionais de 1H e 13C, e cromatografia líquida acoplada à espectrometria de massa. Foram identificados a cumarina, os amburosídeos A e B, e o ácido (Z)-o-cumárico glicosilado. A atividade antimicrobiana foi realizada pela metodologia de microdiluição em placa sobre Escherichia coli, Salmonella Enteritidis, Pseudomonas aeruginosa, Staphylococcus aureus e Listeria monocytogenes. O decocto mostrou atividade antimicrobiana sobre bactérias Gram-positivas. Antimicrobianos naturais podem oferecer vantagens para a produção de alimentos, inibindo microorganismos patogênicos e melhorando a qualidade higiênico-sanitária.