CHEMICAL CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY OF HYDROETHANOLIC CRUDE EXTRACT OF EUGENIA FLORIDA DC (MYRTACEAE) LEAVES

Objective: The present study aimed to characterize and quantify the total phenolics, flavonoids and tannins in a hydroethanolic crude extract (70% (v/v) (EB)) of the leaves of E. florida DC, as well as to evaluate the antimicrobial activity of the extract against different species of micro-organisms.Methods: EB was characterized using a mass spectrometer equipped with a direct insertion device for in-stream injection (FIA). Quantitative analyses of major compounds were carried out by spectrophotometry. In addition, we evaluated the sensitivity profiles of different strains of yeast and bacteria against different concentrations of EB.Results: The classes found were in agreement with those described in the literature: flavonoids, tannins, phenolic acids and saponins. EB showed levels of phenolic compounds, flavonoids and tannins equal to 25.82 mg gallic acid equivalents per gram of extract (EAG/g), 8.42 mg quercetin equivalents per gram of extract (EQ/g) and 7.30 mg tannic acid equivalents per gram of extract (AT/g), respectively. In the analysis of antimicrobial activity, EB was more active against yeasts but was not effective against the bacteria used in the test.Conclusion: We can conclude that E. florida DC has antimicrobial potential, due to the presence of bioactive secondary metabolites.Keywords: Phenolics, Micro-organisms, Mass spectrometer, Yeasts, Bacteria, PotentialÂ

Synthesis, chemical characterization and antimicrobial activity of new acylhydrazones derived from carbohydrates.

A new series of glycosylated acylhydrazones was synthesized and all the chemical structures were confirmed by High Resolution Mass Spectrometry (HRMS), 1 H and 13C Nuclear Magnetic Resonance (1 HNMR; 13C-NMR) and Fourier Transform Infrared (FTIR) spectroscopy methods. The mass accuracy between the calculated and found values observed in HRMS analyses were near or lower than 5 ppm, which are acceptable for proposing a molecular formula using this technique. All of the synthesized compounds were screened for their antibacterial, antifungal and antiviral activities. Five compounds (12, 13, 14, 16 and 19) exerted a modest antifungal activity against the strains evaluated. Derivative 14 showed fungicidal activity against Candida glabrata at 173.8 mM and saccharide unit contributed to the increase of the antifungal potential against this strain. New chemical manipulation of derivative 14 can make it possible to obtain new potentially antimicrobial agents