Search

Abstract: The complexes of [Ln(2,3,4-tmoba)3phen]2 (Ln=Dy (1), Eu (2), Tb (3); 2,3,4-tmoba=2,3,4-trimethoxybenzoate; phen=1,10-phenanthroline) were synthesized and characterized by a series of techniques including the elemental analysis, IR and fluorescent spectra and TG/DSC-FTIR technology. The crystal structures were determined by X-ray crystallography. Each complex include two Ln3+ ions, six 2,3,4-tmoBA and two phen molecules forming a binuclear structure, giving the coordination number of nine. The three-dimensional IR accumulation spectra of gaseous products for the complexes 1 to 3 are analyzed and the thermal decomposition processes are further authenticated. Through means of differential scanning calorimeter (DSC), two solid-solid phase transition endothermic peaks were found in the complex 2, which was different from the complexes 1 and 3. The heat capacities of these complexes were measured and fitted to a polynomial equation with the least squares method for each complex on the basis of the reduce temperature x (x =[T −(T max + T min)/2]/[(T max − T min)/2]) over the range from (256.15 to 476.15)K. Subsequently, the smoothed molar heat capacities and thermodynamic functions (H T−H 298.15K), (S T−S 298.15K), and (G T−G 298.15K) of the complexes 1 to 3 were calculated based on the fitted polynomial of the heat capacities. The fluorescent intensity of the complexes 2 and 3 are markedly improved as well. [Copyright &y& Elsevier]

Candida albicans causes mastitis in dairy cows, which reduces milk production, causes milk quality decline and increases the risk of foodborne infections. Antimicrobial peptides (AMPs) play important roles in insects due to their ability to inhibit the growth of bacteria, fungi and viruses. Moreover, sorbic acid and benzoic acid are widely used preservatives in the food industry. In this study, one of the housefly larval AMPs, Phormicin C-NS, modified with sorbic acid or benzoic acid, was synthesized, and the anti- C. albicans activity was evaluated. In addition, the potential mechanism of action of Phormicin C-NS against C. albicans was revealed by transcriptomic analysis. Phormicin C-NS inhibited the C. albicans bud-to-hyphal transition and biofilm formation by downregulating the hypha-specific genes HWP1 , Ece1p and Als3. Moreover, it inhibited C. albicans propagation in pasteurized milk. The MIC of Phormicin C-NS for C. albicans was nearly 30 times lower than that of sorbic acid. Furthermore, Phormicin C-NS will significantly reduce sorbic acid usage in the milk industry as an alternative peptide. Eventually, the peptide is degraded into amino acids. In summary, Phormicin C-NS has good biosafety, enhances milk amino acid levels, and has great potential as a new preservative for use in the milk industry. [Display omitted] • Phormicin is an insect peptide, and a hemolysis assay demonstrated its good biosafety. • Phormicin is modified with sorbic acid, which is widely used in the food industry. • Phormicin C-NS alternatives would greatly reduce sorbic acid usage. • Phormicin C-NS is spontaneously degraded into amino acids in milk and is nontoxic. • Phormicin C-NS inhibits C. albicans growth in milk, and the underlying mechanism was revealed. [ABSTRACT FROM AUTHOR]