Application of Newly Synthesized Sulfobetaine Based on Sweet Almond Oil in Bath Liquids for Sensitive Skin

Three formulations for bath liquids were developed, differing in the type of amphoteric surfactant applied. The formulations used Cocamidopropyl Betaine, Cocamidpropyl Hydroxide and newly synthesized sulfobetaine based on sweet almond oil (Oleicamidopropyl Sultaine). The molecular structure of the surfactant used in the manufactured formulations has a negatively charged sulfonate group and a positively charged quaternary nitrogen atom. Such molecular structures suggest that the functional properties of this substance are mild. Based on the research, it was found that the bath fluid containing the newly synthesized sulfobetaine based on sweet almond oil had the lowest zein number, the lowest pH increase of bovine albumin solution and the lowest ability to emulsify fatty dirt. This indicates a very low irritant effect of the tested bath liquid.

Effects of Sterols on the Interaction of SDS, Benzalkonium Chloride, and A Novel Compound, Kor105, with Membranes

Sterols change the biophysical properties of lipid membranes. Here, we analyzed how sterols affect the activity of widely used antimicrobial membrane-active compounds, sodium dodecyl sulfate (SDS) and benzalkonium chloride (BAC). We also tested a novel benzalkonium-like substance, Kor105. Our data suggest that benzalkonium and Kor105 disturb the ordering of the membrane lipid packaging, and this disturbance is dampened by cholesterol. The disturbance induced by Kor105 is stronger than that induced by BAC because of the higher rigidity of the Kor105 molecule due to a shorter linker between the phenyl group and quaternary nitrogen. On the contrary, individual SDS molecules do not cause the disturbance. Thus, in the tested range of concentrations, SDS–membrane interaction is not influenced by cholesterol. To study how sterols influence the biological effects of these chemicals, we used yeast strains lacking Lam1–4 proteins. These proteins transport sterols from the plasma membrane into the endoplasmic reticulum. We found that the mutants are resistant to BAC and Kor105 but hypersensitive to SDS. Together, our findings show that sterols influence the interaction of SDS versus benzalkonium chloride and Kor105 with the membranes in a completely different manner.