The aim of this project is to determine the effects of stereochemistry on the kinetic, rheological and thermodynamic behavior of chiral surfactants in monolayers at the air-water interface. There is no previous systemmatic study of this fundamental area despite its extensive implications for biophysical chemistry. An important component will be the investigation of the kinetics of stereoselective reactions between chiral substrates at the air-water interface using a Verger-type Langmuir trough developed primarily for the study of enzymatic reactions in monolayers. Particular concern will be given to clarifying the relationship between stereoselectivity in monolayers and micelles. We know of no previous study of stereoselective reactions in monolayers and the ability to control the degree of orientation should provide valuable information of relevance to biomimetic catalysis. Surfactant structure (chain length and head group), temperature and subphase acidity will be varied to determine the relations between chiral recognition in condensed phases compared to that in expanded phases where molecular packing is ipso facto much looser. Stereochemical interactions will be tested by comparing pure enantiomers versus their racemic mixtures and by comparing diastereomeric mixtures of different chiral surfactants and/or chiral surfactants with chiral additives such as drugs. Surface properties of monolayers will include surface tension, surface pressure, surface potential, surface viscosity and reactions in monolayers. The films will also be transferred to solid substrates and examined by appropriate surface techniques (e.g. elipsometry, FT-infrared, electron microscopy). The results should be of relevance to a broad range of biochemical and biophysical problems which involve the effects of stereoselective interactions as, for example, in membranes, vesicles, micelles, drug transport, asymmetric organic synthesis, resolution of racemic mixtures and lipid oxidation.
Arnett, E M; Gold, J M; Harvey, N et al. (1988) Stereoselective recognition in phospholipid monolayers. Adv Exp Med Biol 238:21-36 |
Arnett, E M; Harvey, N; Johnson, E A et al. (1986) No phospholipid monolayer-sugar interactions. Biochemistry 25:5239-42 |