Triton X-100 micelle

Among them, 38a and 38b are water soluble and they can be considered as the non-micellar counterparts. All other ligands are water insoluble but can be solubilized in CTAB or Triton X-100 micelles. 

The uncatalyzed rates in the Triton X-100 micelle are much smaller than those of the CTAB micelle as expected in ionic micellar reactions. However, in the catalyzed reactions much larger rate enhancements occur in the former micelle than in the latter micelle, similarly as in achiral systems (Table 4, 5). In Table 10, ester 50 shows... 

The ratios of these slopes for L- and D-esters are shown in Table 12. The kL/kD values of the acylation step in the CTAB micelle are very close to those in Table 9, as they should be. It is interesting to note that the second deacylation step also occurs enantioselectively. Presumably it is due to the deacylation ocurring by the attack of a zinc ion-coordinated hydroxide ion which, in principle, should be enantioselective as in the hydroxyl group of the ligand. Alternatively, the enantioselectivity is also expected when the free hydroxide ion attack the coordinated carbonyl groups of the acyl-intermediate with the zinc ion. At any rate, the rates of both steps of acylation and deacylation for the L-esters are larger than those for the D-esters in the CTAB micelle. However, in the Triton X-100 micelle, the deacylation step for the D-esters become faster than for the L-esters. 

Clouding and Aggregation of Triton X-100 Micelles Effect of Additives... 

I didn t use the triton X-100 example because it is a neutral entity. It is fine for an organic chemist, but inorganic entities can t interact with this micelle. However, a triton X-100 micelle is very well studied because biochemists are interested in using it as a model membrane since it makes big flat-disk micelles. Biochemists consider it as resembling a section of membrane, which can solubilize proteins. It is a good model for biological systems. 

In order to more closely represent the volatilization environment that would be encountered in an evaporation pond, Triton X-100, a non-ionic emulsifier similar to those used in some pesticide formulations, was added to prepared pesticide solutions at 1000 ppm. The presence of this emulsifier caused a decrease in the percent pesticide volatilized in one day in all cases except for mevinphos (Table VI). Three mechanisms are probably in operation here. First, Triton X-100 micelles will exist in solution because its concentration of 1000 ppm is well above its critical micelle concentration of 194 ppm (30). Pesticide may partition into these micelles, reducing the free concentration in water available for volatilization, which will in turn reduce the Henry s law constant for the chemical (31). Second, the pesticides may exhibit an affinity for the thin film of Triton that exists on the water surface. One can no longer assume that equilibrium exists across the air-water interface, and a Triton X-100 surface film resistance... 

The photodimerization of coumarin (60) is affected by the presence of micelles (Scheme XXI)52). Alterations in the nature of the micelle by employing anionic (SDS), cationic (HDTBr) and non-ionic (Triton X-100) micelles slightly affect the relative quantum efficiencies of the cycloaddition and supports the contention that... 

Bohm et al. (1997) showed that all the carotenoid radical cations studied reacted efficiently with ascorbic acid (AscH ) in both methanol and Triton X-100 micelles to regenerate (presumably) the parent carotenoid. 

Additional information <1> (<1> the enzyme binds substantial amounts of Triton X-100 and is actually present in detergent-containing solutions as a complex with a molecular weight of 120000 Da. It seems likely that the active species of the enzyme is a single 55000 Da polypeptide chain bound to essentially one Triton X-100 micelle ] ]) [1]... 

Kano et al. (68) used dansyldodecylamine (S-dimethylaminonaphthalene-1-sulfonic acid n-dodecylamide) as a probe in which the energy of the emission maximum decreases with the polarity of the environment. The results show that Triton X-100 micelles provide a less polar environment to the probe than SDS and CTAC micelles. This was discussed in terms of a more rigid structure of the Trition X-100 micelles. 

More quantitively, Fernandez and Fromheiz investigated the interfacial region of SDS, CTAB, and Triton X-100 micelles (194). They used fluorescent pH indicators, hydroxycoumarin and aminocoumarin dyes substituted by alkane chains, and measured shifts of the pK-values. The authors attributed these shifts partly to the dielectric constant at the micelle-water interface and pardy to the electrical potential at the surface of charged micelles. In this way they calculated... 

If we first examine the profile for electrically neutral Triton X-100 micelles, we... 

Brij-35 and Triton-X-100 micelles retard the reaction by 3-5 times. 

Figure 15.3 shows that a decrease in the fraction of ionic surfactant results in a decrease in the catalytic effect. In the case of the Brij-35 and Triton-X-100 micelles... 

Figure 16 Absorption spectra of Cu(II)-CAS complex in different media. Curve 1, in O/W Triton X-100- -C5HiiOH n-C9H2oOH-H20 microemulsion with weight ratio 0.03 0.02 0.005 0.945 curve 2, in Triton X-100 micelles curve 3, in water. (From Ref. 29.)...

Visser, A. J, W. G., van Hoek, A., and van Paridon, P. A, 1987, Time-resolved fluorescence depolarization studies of parinaroyl phosphatidylcholine in Triton X>100 micelles and rat skeletal muscle membranes, in Membrane Receptors. Dynamics, and Energetics, K. W, A, Wirtz (ed.). Plenum Press, New York, pp. 353-361. 

The chemical shifts of various phospholipids in organic solvent and Triton X-100 micelles are shown in Tables 9.13 and 9.14. A detailed discussion on P-NMR of phospholipids in micelles, including applications to membrane solubilization by detergents and phospholipase activity may be found in the recent review of Dennis and Pliickthun (1984). 

CD spectra of borohydride-treated and native Rb, sphaeroides R26 reaction centers are presented in Fig. 4. For comparison, the CD spectra of Rb, sphaeroides wild type strain 2.4.1 reaction centers are presented in Fig. 5. Because CD is a sensitive probe of the structure and environment of bound chromophores, it provides an opportunity to examine whether or not spheroidene is bound in the same manner for all the complexes. Furthermore, it is known that carotenoids are not optically active unless physically bound to the reaction center protein [8]. This is shown in Fig. 5 which demonstrates that spheroidene, incorporated into Triton X-100 micelles at a concentration equal to that of spheroidene bound to the reaction centers, does not display a CD spectrum. Upon binding to the reaction center protein, spheroidene becomes optically active, presumably either through exciton interactions with the amino acid residues in proximity to the chromophore or by an asymmetry in the carotenoid configuration or conformation, and displays a pronoimced CD spectrum. 

XO --MoO - PO -AsO The heteropoly acids formed will be subsequently reduced by ascorbic acid to form heteropoly blue species. Triton X-100 micelles were present... 

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