antifungal activity

Polyphenol oxidase(PPO) is a food enzyme which holds a very important place in the food industry mainly because of its impairing effects. This enzyme leads to the darkening of tissue when fruits are cut or any damage occurs which leads to the depreciation of nutritional value and food acceptability. It is not clear which roles this compound may have in cell metabolism. In plants, PPO contributes to defence mechanisms against pests and pathogens by producing toxic quinones that deter herbivory and inhibit microbial growth. In this report, the possible antifungal effects were examined. Analyses are carried out by properties of standard polyphenolic substances oxidized by PPO were assayed on Red delicious apple extract whose phenolics were previously isolated.

The novel metal chelates of 2-(8-quinolinol-5-yl)–methyl amino-5 -phenyl-1, 3, 4-thiadiazole (1) has been synthesized and their antimicrobial properties were evaluated. These compounds were synthesized by reaction of 2-(8-quinolinol-5-yl)–methyl amino-5 -phenyl-1, 3, 4-thiadiazole (1) with metal acetate and characterized using IR, 1H-NMR and elemental analysis. The synthesized compounds were screened for their in vitro antimicrobial activity against microorganism P. Expansum. B. Thiobromine, Nigras pora Sp. T. roseum, A. Niger, B. megaterium, S. aureus, P. aeruginosa and E. coli. All of the compounds are active against the microorganism in which some are exhibited moderate to good activity, whereas some were less active.

A series of novel benzimidazoles derivatives were synthesized in convenient, easy and cheap way. These benzimidazoles are characterized by bearing amino substituents (morpholine and N-methylpiperazine) at positions 5, in addition to pyrimidine, pyridine, furyl, thienyl and pyryl with amide linkage at positions 2. The methodology of such synthetic routes was represented in synthesis of novel structures that the microbes have never been presented with before; that would hopefully prevent the process in which microbes resist antimicrobial drugs. The structures of all new compounds were identified by 1H-NMR, 13C-NMR, M.S and FT-IR spectroscopic techniques and elemental analysis. All the compounds synthesized in this work were examined for their in vitro antimicrobial activities against Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), and the fungi (C.albicans and A.niger). Compared to Ciprofloxacin and Fluconazole as the reference substances, some of the synthesized compounds showed high antibacterial and antifungal activities against studied strains with inhibition zones between (12-27) mm.