title: Amino Acid based cationic surfactants in aqueous solution: physicochemical study and application of supramolecular chirality in ketone reduction.
abstract: The present study provides a molecular understanding of the origin of the chirality in aqueous micelles and its correlation with the proficiency of stereoselective ketone reduction. The effects of varied headgroup architecture on the surface-active properties as well as on other microstructural parameters were studied and correlated to the structural differences of these naturally occurring amino acid containing surfactants (1-4). Micropolarity sensed by pyrene showed that the micelles prepared using 1-4 are mostly hydrated; particularly large headgroup size surfactant produces more polar environment. A theoretical study was done to quantify the varied spatial dissymmetry for all four surfactants. Asymmetric reduction of prochiral ketones was carried out at the aqueous micellar interface of these chiral amphiphiles by exploiting the supramolecular chirality as evidenced from a circular dichroism study. The enantioselectivity of the reduction process is rationally improved through increase in spatial dissymmetry and steric constraint imposed at the micellar interface by the polar head of surfactants.
authors.affiliation: Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata.
authors.forename: Sangita
authors.initials: S
authors.lastname: Roy
authors.forename: Debapratim
authors.initials: D
authors.lastname: Das
authors.forename: Antara
authors.initials: A
authors.lastname: Dasgupta
authors.forename: Rajendra Narayan
authors.initials: RN
authors.lastname: Mitra
authors.forename: Prasanta Kumar
authors.initials: PK
authors.lastname: Das
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002412:Cations; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D007659:Ketones / Q000737:chemistry*; D012996:Solutions; D013050:Spectrometry, Fluorescence; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D002412:Cations; D007659:Ketones; D012996:Solutions; D013501:Surface-Active Agents