ABSTRACT
The toxicity of new surfactants containing a beta-lactam ring has been established by studying their interaction with a hybridoma cell line. An hour of contact is sufficient to generate an apoptotic signal after two days of culture. Under the experimental conditions chosen for the experiments, surfactants have been divided into three categories: i) biocompatible and non-apogenic; ii) surfactants triggering an apoptotic signal without inducing cell necrosis; iii) surfactants triggering an apoptotic signal at low concentrations and destroying the cells by necrosis at higher concentrations. The necrosis inducing surfactants also had haemolytic properties. These properties were related to the values of the hydrophilic-lipophilic balance of the molecules.
Subject(s)
Apoptosis , Detergents/toxicity , Erythrocytes/drug effects , Surface-Active Agents/toxicity , beta-Lactams/chemistry , Animals , Cell Survival , Detergents/chemistry , Hemolysis/drug effects , Humans , Mice , Molecular Structure , Surface-Active Agents/chemistry , Toxicity Tests , Tumor Cells, Cultured , beta-Lactams/analysisABSTRACT
Starting from glutamic acid, different types of surfactants have been synthesised by using original trimodular strategies. Monosubstituted zwitterionic amides of glutamic acid obtained with excellent yields show good surface activity. The grafting of a second hydrophobic side-chain leads to bicatenar cationic surfactants or to disubstituted nonionic cyclic compounds. In order to reduce the hydrophobic character of the bicatenar surfactants, a second synthetic method has been developed, allowing the introduction of a polar sugar group into these molecules. The surfactant properties of several of the products have been determined by physico-chemical methods such as surface tension measurements and compression isotherm studies by means of a Langmuir balance.
Subject(s)
Glutamic Acid/analogs & derivatives , Glutamic Acid/chemical synthesis , Surface-Active Agents/chemical synthesis , Alcohols/chemistry , Amines/chemistry , Magnetic Resonance Spectroscopy , Models, Chemical , Spectrophotometry, InfraredABSTRACT
The reaction of amines of sodium azide with 3-perfluoroalkyl-3-fluoroprop-2-enoate, followed by hydrogenation, affords perfluoroalkylated beta-alanine analogues in very good yields. These compounds can be linked via an amide bond to produce peptide analogues such as carnosine or carcinine derivatives, which could have surfactive and complexing properties.
Subject(s)
Peptides/chemical synthesis , Surface-Active Agents/chemistry , Acrylates/chemistry , Blood Substitutes , Carnosine/analogs & derivatives , Carnosine/chemistry , Fluorocarbons/chemistry , Peptides/chemistry , Sodium Azide/chemistryABSTRACT
Micellar extraction coupled with ultrafiltration techniques represents a potentially attractive tool for the removal of different kinds of contaminants from waste waters. Even though most industrial streams to be treated contain large amounts of electrolytes, very little is known about the behavior of micellar solutions in ultrafiltration when large amounts of salts are present. This paper is concerned with an investigation of two cationic surfactants (cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC)) and one anionic surfactant (sodium dodecylsulfate (SDS)) in the presence of several salts occurring in specific industrial processes (carbonates and hydrogenocarbonates, nitrites, nitrates). The ultrafiltration behavior of these systems, with individual salt concentrations up to 0.9 M, is studied from the viewpoint of the fluxes obtained, the amount of surfactant leakage and of the membrane "gel point." Two types of polymeric membranes with molecular weight cutoff of 10,000 Da are considered (cellulose and polysulfone), which show significantly different behaviors.