This work reports the theoretical and experimental study of fragmentation reactions in the gas phase of five phenolic acids using triple quadrupole mass spectrometry by electrospray ionization in negative ionic mode, as well as the isotope exchange experiments. MS/MS spectra were analyzed to suggest the fragmentation mechanisms, while theoretical calculations at the theory level B3LYP/6-311+G** were performed to expose the proposed mechanisms viability for this class of compounds. As expected, compounds with aromatic methoxy substitution presented •CH 3 radical elimination as the principal fragmentation pathway, forming dystonic ions. Compounds without methoxy substituents dissociate with higher energies losing the CO 2 , CO and H 2 O. The isotopic marking experiments indicated the exchange of hydrogens by deuterases in the hydroxyl protons, which corroborates with the proposed mechanisms.
Poly(ε-caprolactone), an aliphatic polyester with biodegradability and cytocompatibility, has been used to create scaffolds for tissue engineering purposes. However, the hydrophobicity and low water absorptivity of poly(ε-caprolactone) reduce cell anchorage on their membranes. Here, poly(ε-caprolactone)-based scaffolds were prepared by electrospinning of poly(ε-caprolactone)chitosan blend, and poly(ε-caprolactone)-dexamethasone solution. Chitosan and dexamethasone play an essential role to increase the scaffolding performance of poly(ε-caprolactone)-based electrospun membranes. A poly(ε-caprolactone) membrane without chitosan and dexamethasone did not provide satisfactory results to promote cell culture of adipose mesenchymal stem cells (AMSCs). Compared to the poly(ε-caprolactone)-dexamethasone surface, poly(ε-caprolactone)chitosan membrane imparts better cytoskeletal reorganization, and cell spreading, increasing the strength of cell attachment. Also, poly(ε-caprolactone)-chitosan composite provides strong antimicrobial activity against Pseudomonas aeruginosa (ca. 90% inhibition). Therefore, the poly(ε-caprolactone)-chitosan composite is a better alternative to treat skin diseases and promote skin regeneration than conventional approaches based on dexamethasone.
Cereal bars are considered a nutritious food with sweet and pleasant taste, source of vitamins, minerals, fiber, proteins and complex carbohydrates, besides its convenience and association with healthy foods. The present work produced a cereal bar enriched with collagen, and had as objective to analyze the physical-chemical, microbiological and sensorial characteristics. Determinations of ash, acidity, proteins, fibers, moisture and pH were performed. The samples were submitted to microbiological analysis of Salmonella spp., total and thermotolerant coliforms. The results showed that the collagen-containing cereal bars had a relatively acidic pH (6.08) and could favor inhibition of growth of microorganisms. In addition, the samples presented high fiber content, a fact that adds nutritional value to the product. The cereal bars produced with collagen, presented higher protein content when compared to the bars of cereals available in the market. In the analyzes of acceptability and intention of purchase the bar with collagen presented good acceptability for the attributes of appearance and flavor. Thus, the development of cereal bars with addition of collagen becomes viable as an alternative for the development of new products with high nutrient value.
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