2390-84-3Relevant academic research and scientific papers
Experimental and Computer Modeling Studies of Micellar Diastereoselectivity
Moss, Robert A.,Hendrickson, Thomas F.,Ueoka, Ryuichi,Kim, Kwang Yoo,Weiner, Paul K.
, p. 4363 - 4372 (2007/10/02)
Diastereomeric dipeptide p-nitrophenyl esters, Z-(D or L)-Pro-L-Pro-PNP, or Z-(D or L)-Trp-(L)-Pro-PNP, were cleaved at pH 8 in buffer, nonfunctional cetyltrimethylammonium (CTA) ion micelles, and in thiolate- or iodosobenzoate-functionalized micelles.Kin
Origins of Micellar Diastereoselectivity
Moss, Robert A.,Chiang, Yuan-Ching P.,Hui, Yongzheng
, p. 7506 - 7513 (2007/10/02)
Thiol-functionalized surfactant micelles (n-C12H25N+Me2CH2CH2SH,Cl-) were used to cleave Z-Trp-Pro p-nitrophenyl dipeptide esters.Marked kinetic diastereoselectivity was observed in these reactions.For example at pH 8 and concentrations (ca.6-7)x1E-3 M, the micellar thiol cleaved the LL substrate 5-6 times more rapidly than its DL diastereomer.This kinetic diastereoselectivity was shown to develop at surfactant concentrations ca.5x1E-3 M, considerably above the cmc (ca.1x1E-3 M), i.e., at a second "critical concentration".Dynamic light-scattering measurements showed that micelles which had reacted with the LL (but not the DL) substrate underwent a marked increase in apparent hydrodynamic diameter (from ca. 15 to 26 nm) near this second critical concentration.Similar phenomena could be induced upon addition of 2x1E-5 M LL dipeptide surfactant reaction product to the thiol micelles.Micelles of n-C12H25N+Me2CH2CH2OH,Cl- or n-C12H25N+Me3,Cl- were unresponsive to such additions (light scattering).The results are discussed in terms of molecular and supramolecular interactions between surfactant and solubilizate molecules.
