Search results

Filters

  • Journals
  • Date

Search results

Number of results: 2
items per page: 25 50 75
Sort by:

Abstract

Five new derivatives of 4,6-di(thiophen-2-yl)pyrimidine (DTP) were designed by structural modification with the aim to tune the electro-optical and charge transfer properties. The effect of oligocene and oligocenothiophene incorporation/substitution was investigated on various properties of interests. The smaller hole reorganization energy revealed that compounds 1-5 might be good hole transfer contenders. The smaller hole reorganization energy of newly designed five DTP derivatives than the pentacene showed that prior compounds might be good/comparable hole transfer materials than/to that of pentacene. The computed electron reorganization energy of DTP derivatives 1-5 are 124, 185, 93, 95 and 189 meV smaller than the meridional-tris (8-hydroxyquinoline) aluminum (mer-Alq3) illuminating that electron mobility of these derivatives might be better/comparable than/to referenced compound.
Go to article

Abstract

MDAP-2 is a new antibacterial peptide with a unique structure that was isolated from house- flies. However, its biological characteristics and antibacterial mechanisms against bacteria are still poorly understood. To study the biological characteristics, antibacterial activity, hemolytic activi- ty, cytotoxicity to mammalian cells, and the secondary structure of MDAP-2 were detected; the results showed that MDAP-2 displayed high antibacterial activity against all of the tested Gram-negative bacteria. MDAP-2 had lower hemolytic activity to rabbit red blood cells; only 3.4% hemolytic activity was observed at a concentration of 800μg/ml. MDAP-2 also had lower cytotoxicity to mammalian cells; IC50 values for HEK-293 cells, VERO cells, and IPEC-J2 cells were greater than 1000 μg/ml. The circular dichroism (CD) spectra showed that the peptide most- ly has α-helical properties and some β-fold structure in water and in membrane-like conditions. MDAP-2 is therefore a promising antibacterial agent against Gram-negative bacteria. To deter- mine the antibacterial mechanism(s) of action, fluorescent probes, flow cytometry, and transmis- sion electron microscopy (TEM) were used to study the effects of MDAP-2 on membrane perme- ability, polarization ability, and integrity of Gram-negative bacteria. The results indicated that the peptide caused membrane depolarization, increased membrane permeability, and destroyed membrane integrity. In conclusion, MDAP-2 is a broad-spectrum, lower hemolytic activity, and lower cytotoxicity antibacterial peptide, which is mainly effective on Gram-negative bacteria. It exerts its antimicrobial effects by causing bacterial cytoplasm membrane depolarization, increas- ing cell membrane permeability and disturbing the membrane integrity of Gram-negative bacte- ria. MDAP-2 may offer a new strategy to for defense against Gram-negative bacteria.
Go to article

This page uses 'cookies'. Learn more