https://www.selleckchem.com/products/bufalin.html The interactions between calf thymus DNA, ctDNA, and a series of sugar-based gemini cationic surfactants with different hydrophobic chains were investigated. The surface properties of the cationic gemini surfactants were firstly examined, and then their interactions with DNA and induced condensation of DNA were studied by UV-vis, ethidium bromide exclusion assay, circular dichroism, dynamic light scattering, zeta potential and atomic force microscopy. With the increase of hydrophobic chains of the surfactants, critical micelle concentrations decreased significantly, and the interactions with DNA were remarkably strengthened, with the binding constant up to 1.95 × 107 L·mol-1 according to fluorescence quenching experiments by ethidium bromide exclusion. The gemini surfactant with hexadecyl hydrocarbon chain, 1c, exhibited the highest compaction capacity for DNA, accompanied with conformation changes, as confirmed by CD and DLS measurements. The DNA molecules could be compacted to about 140 nm in hydrodynamic diameter at 0.2 mM of 1c, and the overall shifts of the positive band and significant increase of negative molar ellipticity indicated the formation of a supramolecualr chiral order of ѱ phase in which DNA were supposed to be tightly packed. V.Caloric reduction (CR) is considered as the most reasonable intervention to delay aging and age-related diseases. Numerous studies in various model organisms provide the main basis for this hypothesis. Human studies exist, but they differ widely in study design, characteristics of test persons and study outcome. In this study we investigated CR in humans on a molecular level to gain a better understanding in these processes. For that purpose, we analyzed human peripheral blood mononuclear cells of healthy people fasting according to F. X. Mayr. In a previous study our group could show a significantly improved DNA repair capacity after fasting. Here we were able to confirm th