Surface Activities, Antibacterial Activity and Corrosion Inhibition Properties of Gemini Quaternary Ammonium Surfactants with Amido Group and Carboxylic Counterions

The Interaction of a Gemini Surfactant with a DNA Quadruplex

DNA secondary structures are stabilized by mono- and divalent cations. To examine the stability of the DNA quadruplex formed from (TTAGGG)4, its interaction with a dicationic Gemini surfactant in standard phosphate buffer was investigated. The Gemini surfactant begins to form micelles in buffer at a cmc (critical micelle concentration) of 1.5 mM. In this study, solutions of DNA were prepared in buffer with surfactant concentrations ranging from 0.0 to 3.0 mM, i.e., above and below the cmc of the surfactant. In all samples of DNA and surfactant, a precipitate formed. The fraction of DNA precipitated depends upon both the initial DNA concentration and the initial concentration of the surfactant. In those samples where the DNA did not totally precipitate, the residual DNA assumed a quadruplex conformation. It was determined that two surfactant molecules per DNA phosphate are needed to completely precipitate all of the DNA in a particular sample. An estimated apparent K sp for the DNA:surfactant complex was determined.

Advances in the Synthesis of Biologically Active Quaternary Ammonium Compounds

This review provides a comprehensive overview of recent advancements in the design and synthesis of biologically active quaternary ammonium compounds (QACs). The covered scope extends beyond commonly reviewed antimicrobial derivatives to include synthetic agents with antifungal, anticancer, and antiviral properties. Additionally, this review highlights examples of quaternary ammonium compounds exhibiting activity against protozoa and herbicidal effects, as well as analgesic and anesthetic derivatives. The article also embraces the quaternary-ammonium-containing cholinesterase inhibitors and muscle relaxants. QACs, marked by their inherent permanent charge, also find widespread usage across diverse domains such as fabric softeners, hair conditioners, detergents, and disinfectants. The effectiveness of QACs hinges greatly on finding the right equilibrium between hydrophilicity and lipophilicity. The ideal length of the alkyl chain varies according to the unique structure of each QAC and its biological settings. It is expected that this review will provide comprehensive data for medicinal and industrial chemists to design and develop novel QAC-based products.

New Technology for the Synthesis of Glycerol Monooleate

Herein, a new approach for glycerol monooleate (GMO) was developed. GMO was synthesized via the esterification method using self-made sodium oleate and 3-chloro-1,2-propanediol as reactants, tetrabutylammonium bromide as the catalyst, and toluene as the solvent. The effects of the reaction molar ratio, type and amount of catalyst, and reaction temperature and time on the yield were investigated. Results showed that the optimal process conditions for synthesizing GMO were as follows. The molar ratio of sodium oleate to 3-chloro-1,2-propanediol was 1:2, the reaction temperature was 115°C, the reaction time was 6 h, weight of toluene was 25 g, and the catalyst dosage was 3.5%. Under these conditions, high-purity GMO was synthesized with a yield of 89.02%.