Lipoate Ester Multifunctional Lubricant Additives

Construction of Peptide-Lipoic Acid Cationic Polymers with Redox Responsiveness and Low Toxicity for Gene Delivery

As gene therapy continues to evolve, the development of safe and effective cationic polymer carriers is critical. In this work, three polymers have been prepared by ring-opening polymerization on the basis of peptide-lipoic acid monomers. By adjusting the sequence of the peptides, redox-responsive cationic polymers with different positive charge numbers were obtained, as well as investigating their performance as gene carriers. The results showed that the polymers complexed with negatively charged genes by electrostatic interaction and successfully transported the genes into the cells, additionally degrading and releasing the genes under glutathione (GSH) conditions. Furthermore, the polymers as gene carriers in different cell lines demonstrated lower cytotoxicity, with an excellent cell survival rate of 8 times higher than the "gold standard" polyethylenimine (PEI) at the same concentration. In vitro transfection experiments showed that the polymers successfully released and transfected genes into cells, demonstrating their immense potential in gene therapy.

Modular Routes to 1,3-Dithian-2-ones and 1,2-Dithiolanes

Convergent routes to 1,3-dithian-2-ones based on the radical addition of xanthates to alkenes possessing a suitably located (latent) leaving group are described. These can be converted into 1,2-dithiolanes by base-mediated hydrolysis and oxidation. A broad variety of functional groups can be introduced, and the process is modular, uses inexpensive starting materials and reagents, and is atom economical, because both sulfur atoms of the xanthate end up in the products.

On the study of cucurbit[6]uril and 4-tert-butylcalix[6]arene as multifunctional lubricant additives

Cucurbit[6]uril and 4-tert-butylcalix[6]arene are found to be efficient multifunctional lubricant additives.

Multifunctional lubricant additive based on difluoroboron derivatives of a diphenylamine antioxidant

A metal-free and phosphorus-free novel multifunctional additive (E)-4-((3-(tert-butyl)-2-((difluoroboranyl)oxy)-5-((octylthio)methyl)benzylidene)amino)-N-phenylaniline (difluoroboron derivative 4a) was synthesized and characterized. The results show that its antioxidation and tribological properties are better than those of base oil, diphenylamine and zinc dialkyldithiophosphate (ZDDP), and it can also increase the extreme pressure performance of the base oil. In addition, it can be found that the diphenylamine functional group, boron and fluorine are the main contributors to the excellent antioxidation and antiwear properties of difluoroboron derivative 4a, respectively. Finally, the results of X-ray photoelectron spectroscopy on the worn surfaces reveal that B₂O₃, Fe₂O₃, a N-containing organic compound and iron fluoride comprise the boundary films, which effectively improve the difluoroboron derivative 4a's antiwear properties.