Chromatography reverse-phase thin layer

The lipophilicity (7 m value) and specific hydrophobic surface area of 1 ]/f-pyrido[2,]-fi]quinazolin-] 1-one and its isomeric 6//-pyrido[l, 2-u]qui-nazolin-6-one were determined by reversed-phase thin-layer chromatography (98MI4). 

In reversed-phase thin-layer chromatography (RP-TLC), the choice of solvents for the mobile phase is carried out in a reversed order of strength, comparing with the classical TLC, which determines a reversed order of values of compounds. The reversed order of separation assumes that water is the main component of the mobile phase. Aqueous mixmres of some organic solvents (diethyl ether, methanol, acetone, acetonitrile, dioxane, i-propanol, etc.) are used with good results. 

Lipophilicity and specific hydrophobic surface area were determined by using reversed-phase thin-layer chromatography for fused heterocyclic ring systems including five pyrido[2,iy][l,2,4]triazine derivatives <1998MI64>. 

The logarithm of the 1 -octanol - water partition coefficient, denoted log Kq j or log P, indicates the distribution of the compound between the organic and the water phase. For highly lipophilic compounds, the log P is determined via reversed-phase thin-layer chromatography, giving the so-called log P tlc value1. 

Reversed-phase thin-layer chromatography (TEC) (Ellgehausen et al. 1981, Bruggeman et al. 1982). 

Bruggeman, W. A., van der Steen, J., Hutzinger, O. (1982) Reversed-phase thin-layer chromatography of polynuclear aromatic hydrocarbons and chlorinated biphenyls. Relationship with hydrophobicity as measured by aqueous solubility and octanol-water partition coefficient. J. Chromatogr. 238, 335-346. 

T. Cserhati, E. Forgacs and J. Hollo, Separation of color pigments of Capsicum annuum by adsorption and reversed phase thin layer chromatography. J. Planar Chromatogr.—Mod. TLC 6 (1993) 472 175. 

R.T. Evans, B. Fried and J. Sherma, Effects of diet and larval trematode parasitism on lutein and / -carotene concentrations in planorbid snails as determined by quantitative high performance reversed phase thin layer chromatography. Comp. Biochem. Physiol. PartB 137 (2004) 179-186. 

D.M. Milojkovic-Opsenica, K. Lazarevic, V. Ivackovic and Z.Lj. Tesic, Reversed-phase thin-layer chromatography of some foodstuff dyes. J. Planar Chromatogr.-Mod TLC, 16 (2003) 276-279. 

Renberg, L.O., Sundstrom, S.G., and Rosen-Olofsson, A.-C. The determination of partition coefficients of organic compounds in technical products and waste waters for the estimation of their bioaccumulation potential using reversed phase thin layer chromatography, Toxicol. Environ. Chem., 10 333-349, 1985. 

A process in which the polarity of the stationary and mobile phases is reversed—i.e., the stationary phase is apolar and the solvent is polar—is known as reversed-phase thin-layer chromatography (RP-TLC). 

Isaksen M and Francis GW, Reversed-phase thin-layer chromatography of carotenoids. J Chromatogr 355 358-362 (1986). 

I. D. Wilson, S. Scalia, and E. D. Morgan, Reversed-phase thin-layer chromatography for the separation and analysis of ecdysteroids, J. Chromatogr., 212 211 (1981). 

Renberg, L., Sundstrom, G. (1979) Prediction of bioconcentration potential of organic compounds using partition coefficients derived from reversed phase thin layer chromatography. Chemosphere 7, 449 459. 

Mathew, T.V. and Kamath, K.S. (1978) Detection of vegetable oils in ghee and vice versa by reverse phase thin layer chromatography. Research and Industry, India, 23, 168-169. 

The utility of the highly soluble 6-cyclodextrin derivatives (soluble polymer and dimethyl-6-cyclodextrin) in RPTLC is illustrated in the separation of barbiturates. The lipophilicity of a barbiturate or any guest decreases when included in a cyclodextrin-cavity. Therefore its mobility is modified in reversed phase thin layer chromatography. With this simple and rapid method, the stability of a complex can be estimated empirically (Table II). The "b" value of the following equation is characteristic for the complex stability (in water ethanol =4 1 solution, R determined at 5 different cyclodextrin concentrations for 21 barbiturates) ... 

Partition Data of Chemotherapeutic and Steroid Agents Determined by Reversed-Phase Thin Layer Chromatography... 

A number of o- and ir values for substituents which were present within our set of compounds were missing in the published compilations. We calculated them from the regression equations in Figures 4 and 5. An interesting feature of both equations is that the substituent R at the carbonyl group of the hydrazones contributes in a very different way from that of the substituents in the aromatic ring to pK as well as to log P. Rm values from reversed-phase thin-layer chromatography (TLC) correlated poorly with the w constants and thus cannot be used in this case to derive hydrophobic substituent parameters (18). 

The log Kow values of Chloralkylene-12 components determined by reversed phase thin layer chromatography ranged from 4.56 to 9.53 with increasing chlorine and alkyl substitution degree [68]. Accordingly, isopropyl-PCBs could have a high bioconcentration potential. However, the first accumulation and excretion study of Chloralkylene-9-14C showed rapid metabolism in rats [69]. 

Jack, D.B., Hawker, J.L., Rooney, L., Beerahee, M, Loboand, J., Patel, P. (1988) Measurement of the distribution coefficients of several classes of drug using reversed-phase thin-layer chromatography. J. Chromatogr. 452, 257-264. 

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