Effect of New Surfactants on Biological Properties of Liquid Soaps

Liquid soaps are the basic cosmetics used to clean the skin of the hands. Frequent hand washing prevents viral contamination but may damage the skin’s hydro-lipid layer, leading to various types of irritation. Therefore, four liquid soap formulas were developed with three amphoteric surfactants: Cocamidopropyl Betaine (LS II), CocamidopropylHydroxysultaine (LS III), and newly synthesized Evening PrimroseaamidopropylSulfobetaine (LS IV). We evaluated the skin irritating potential (zein number, bovine albumin test) and cytotoxicity (AlamarBlue™, Cell viability, and Cell cycle assays) on HaCaT cell line. We observed lower values of the zein number and bovine albumin tests after adding soaps with surfactants (the highest differences in LS IV) compared to the base soap (LS I). However, LS I and LS II did not differ in cytotoxic assays. Therefore, adding LS III and LS IV seems potentially more dangerous to the cells. However, it should be noted that cells were continuously exposed to liquid soaps for more than 24 h, so its cytotoxic effects after dermal use in humans may be unnoticeable. Concluding, results suggest that the newly synthesized LS IV should improve the safety of liquid hand washing soaps.     

Crystal nucleation in an electric field

Nucleation of polar and apolar crystals in an electrostatic field has been analyzed. The analysis is based on the extended nucleation theory which takes into account orientation of amorphous kinetic elements and the resulting crystals. In an electric field free energy of transformation is orientation-dependent which leads to orientation and field effects in thermodynamic (critical crystallization temperature) and kinetic crystallization characteristics (thermal and athermal nucleation rates).     

Studies on the reaction of trityl derivatives with H‐phosphonate diesters: Their relevance to the synthesis of 4‐pyridylphosphonates

Transesterification of diphenyl H‐phosphonate with tritanol in pyridine afforded equimolar amounts of phenyl H‐phosphonate monoester and diphenyl 4‐pyridylphosphonate as the only phosphorus‐containing species. Using ³¹P NMR spectroscopy a plausible reaction pathway for the observed transformation was proposed and some of the postulated intermediates were identified. These studies also enabled us to develop an efficient protocol for the formation of diphenyl and diethyl 4‐pyridylphosphonates from the corresponding H‐phosphonate diesters under mild reaction conditions. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 492–499, 1999     

Stereospecific synthesis of P-epimeric (Rp1, Rp2)-bis-[O-l-menthylphenylphosphonothionyl] diselenide. A new variant of the stereoselective Staudinger reaction

An efficient procedure is described that leads to pure (S_P)- O -l-menthylphenylthiophosphinate. The absolute configuration of this diastereomer was assigned by chemical correlation and confirmed by X-ray crystallography. The reaction of the isomer with phenyl azide, leading to amidate, is a new variant of the stereoselective Staudinger reaction. Addition of elemental selenium to the (S_P)-thiophosphinate led to diastereomeric O-l-menthylphenylselenophosphonothioic acid, which was finally oxidized to the diastereomeric (R_P1,R_P2)-bis-[O-l-menthylphenylphosphonothionyl] diselenide. The diselenide structure was unambiguously confirmed by ³¹P NMR spectroscopy.