2,2'-(Ethylenedioxy)bis(ethylamine)

Objective:To evaluate the acute toxicity of carboxymethyl chitosan-2, 2' ethylenedioxy bis-ethylamine-folate (CMC-EDBE-FA) and as well as possible effect on microbial growth and in vitro cell cyto-toxicity. Methods:CMC-EDBE-FA was prepared on basis of carboxymethyl chitosan tagged with folic acid by covalently linkage through 2, 2' ethylenedioxy bis-ethylamine. In vivo acute toxicity, in vitro cyto-toxicity and antimicrobial activity of CMC-EDBE-FA nanoparticle were determined. Results:Vancomycin exhibited the antibacterial activity against vancomycin sensitive Staphylococcus aureus, but CMC-EDBE-FA nanoparticle did not give any antibacterial activity as evidenced by minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), disc agar diffusion (DAD) and killing kinetic assay. Further, the CMC-EDBE-FA nanoparticle showed no signs of in vivo acute toxicity up to a dose level of 1 000 mg/kg p.o., and as well as in vitro cyto-toxicity up to 250 µg/mL.Conclusions:These findings suggest that CMC-EDBE-FA nanoparticle is expected to be safe for biomedical applications.

The Fenton reaction has attracted extensive attention due to its potential to be a highly efficient and environmentally friendly wastewater treatment technology. Noble copper-doped carbon dots (CuCDs) are prepared through a simple one-step hydrothermal method with 3,4-dihydroxyhydrocinnamic acid, 2,2'-(ethylenedioxy)bis(ethylamine) and copper chloride, endowing the Fenton reaction with enhanced catalytic activity for rhodamine B (RhB) degradation. The effects of the concentration of CuCDs, temperature, pH, oxygen (O2), metal ions and polymers on the catalytic activity of CuCDs are investigated. It is worth noting that electron transfer happening on the surface of CuCDs plays a vital role in the RhB degradation process. As evidenced by radical scavenger experiments and electron spin resonance (ESR) studies, CuCDs significantly boost the formation of hydroxyl radicals (˙OH) and singlet oxygen (1O2), facilitating the Fenton reaction for RhB degradation. Due to the strong oxidation of ROS generated by the Fe2+ + H2O2 + CuCD system, RhB degradation may involve the cleavage of the chromophore aromatic ring and the de-ethylation process. Additionally, the toxicity of RhB degradation filtrates is assessed in vitro and in vivo. The as-prepared CuCDs may be promising catalytic agents for the enhancement of the Fenton reaction.

Mechanochemical syntheses of rotaxanes have attracted considerable attention of late because of the superior reaction rates and higher yields associated with their production compared with analogous reactions carried out in solution. Previous investigators, however, have focused on the demonstration of the mechanochemical syntheses of rotaxanes per se, rather than on studying the solid-phase host-guest molecular interplay related to their rapid formation and high yields. In this investigation, we attribute the lower yields of rotaxanes prepared in solution to the limited concentration and a desolvation energy penalty that must be compensated for by host-guest interactions during complexation that precedes the templation leading to rotaxane formation. It follows that, if the desolvation energy can be removed and higher concentrations can be attained, even weak host-guest interactions can drive the complexation of host and guest molecules efficiently. In order to test this hypothesis, we chose two host-guest pairs of permethylated pillar[5]arene/1,6-diaminohexane and permethylated pillar[5]arene/2,2'-(ethylenedioxy)bis(ethylamine) for the simple reason that they exhibit extremely low binding constants (2.7 ± 0.4 M-1 when 1,6-diaminohexane is the guest and <0.1 M-1 when 2,2'-(ethylenedioxy)bis(ethylamine) is the guest in CDCl3; i.e., ostensibly no pseudorotaxane formation is observed). We argue that the amount of pseudorotaxanes formed in the solid state is responsive to mechanical treatments or otherwise and changes in temperature during stoppering reactions. Compared to the amount of pseudorotaxanes that can be obtained in solution, large quantities of pseudorotaxanes are formed in the solid state because of concentration and desolvation effects. This mechanochemical enhancement of pseudorotaxane formation is referred to as a self-correction in the current investigation. Rotaxanes based on permethylated pillar[5]arene/1,6-diaminohexane and permethylated pillar[5]arene/2,2'-(ethylenedioxy)bis(ethylamine) have been synthesized in much higher yields compared to those obtained in solution, aided and abetted by self-correction effects during mechanical treatments and heating at a mild temperature of 50 °C.