Modification of Antibiotic Activity by Fixed Oil of the Artocarpus heterophyllus Almond against Standard and Multidrug-Resistant Bacteria Strains.

Artocarpus heterophyllus (jackfruit) is an evergreen tree distributed in tropical regions and is among the most studied species of the genus Artocarpus. The jackfruit almond has been highlighted in relation to phytochemical studies, biological properties, and application in the development of food products. This study aimed to analyze jackfruit fixed oil regarding chemical components, antibacterial property alone, and in association with antibiotics against standard and MDR bacteria strains. In the analysis of the oil by gas chromatography coupled to a flame ionization detector (GC-FID), a high content of saturated fatty acids (78.51%) was identified in relation to unsaturated fatty acids (17.07%). The main fatty acids identified were lauric acid (43.01%), myristic acid (11.10%), palmitic acid (6.95%), and oleic acid (15.32%). In the antibacterial analysis, broth microdilution assays were used. The oil presented minimum inhibitory concentration (MIC) ≥ 1024 µg/mL in antibacterial analysis for standard and MDR bacterial strains. The oil showed synergistic effects in the association with gentamicin, ofloxacin, and penicillin against MDR strains, with significant reductions in the MIC of antibiotics. The results suggest that the fixed oil of A. heterophyllus has fatty acids with the potential to synergistically modify antibiotic activity.

Matrix effect in guava multiresidue analysis by QuEChERS method and gas chromatography coupled to quadrupole mass spectrometry.

"Quick, Easy, Cheap, Effective, Rugged and Safe" (QuEChERS)-GC/MS analytical technique was used to evaluated matrix effect of twenty-two pesticides in guava. Validation parameters (selectivity, linearity, LOD, LOQ, accuracy and precision) were determined for multiresidue analysis. Statistical test (t-student) was applied to the coefficients of the curves obtained for the guava matrix. The matrix effect (ME) for each pesticide was evaluated through the study of slope ratios obtained of solvent and guava matrix curves. Most of the compounds had positive ME. The rates of recovery were satisfactory (73.97-119.38%), with a coefficient of variation (CV) less than 20%. Analysis of commercial guava samples showed the presence of 5 types of pesticides residues at levels ranging from 0.1 to 0.5 mg·kg(-1). The results reveal the presence of unauthorized pesticides for cultivation of guava. This data can assist government agencies to ensure food security.

Evaluation of an analytical methodology using QuEChERS and GC-SQ/MS for the investigation of the level of pesticide residues in Brazilian melons.

A multiresidue method based on the sample preparation by modified QuEChERS and detection by gas chromatography coupled to single quadruple mass spectrometers (GC-SQ/MS) was used for the analysis of 35 multiclass pesticides in melons (Cucumis melo inodorus) produced in Ceara-Brazil. The rates of recovery for pesticides studied were satisfactory (except for the etridiazole), ranging from 85% to 117% with a relative standard deviation (RSD) of less than 15%, at concentrations between 0.05 and 0.20 mg kg(-1). The limit of quantification (LOQ) for most compounds was below the MRLs established in Brazil. The combined relative uncertainty (Uc) and expanded uncertainty (Ue) was determined using repeatability, recovery and calibration curves data for each pesticide. Analysis of commercial melons samples revealed the presence of pesticides bifenthrin and imazalil at levels below the MRLs established by ANVISA, EU and USEPA.