Effect of the Silica-Magnetite Nanocomposite Coating Functionalization on the Doxorubicin Sorption/Desorption.

A series of new composite materials based on FeO magnetic nanoparticles coated with SiO (or aminated SiO) were synthesized. It has been shown that the use of -(phosphonomethyl)iminodiacetic acid (PMIDA) to stabilize nanoparticles before silanization ensures the increased content of a SiO phase in the FeO@SiO nanocomposites (NCs) in comparison with materials obtained under similar conditions, but without PMIDA. It has been demonstrated for the first time that the presence of PMIDA on the surface of NCs increases the level of Dox loading due to specific binding, while surface modification with 3-aminopropylsilane, on the contrary, significantly reduces the sorption capacity of materials.

Acylative kinetic resolution of racemic methyl-substituted cyclic alkylamines with 2,5-dioxopyrrolidin-1-yl ()-2-phenoxypropanoate.

The diastereoselective acylation of a number of racemic methyl-substituted cyclic alkylamines with active esters of 2-phenoxypropanoic acid was studied in detail. The ester of ()-2-phenoxypropanoic acid and -hydroxysuccinimide was found to be the most selective agent. The highest stereoselectivity was observed in the kinetic resolution of racemic 2-methylpiperidine in toluene at -40 °C (selectivity factor = 73) with the predominant formation of (,)-amide (93.