Bovine serum albumin compounds separated using

CE is playing a major role in the separation of chiral compounds, a field that is gaining increasing attention in pharmaceutical sciences as well as in forensic toxicology (Lurie, 1994 Novotny et al., 1994 Ward, 1994). The chirally active selectors used in CE include optically active complexes such as Cu(II)-l-histidine, Cu(II)-aspartame, cyclodextrins, modified CDs, bile salts, crown ethers, and proteins (bovine serum albumin, aracid glycoprotein, etc.). 

Proteins with their inherent chiral nature are used in CSPs in coated and immobilized form. Bovine serum albumin was the first used in SCP in immobilized form [85] for the separation of acidic and neutral compounds. 

Aaltonen et al. (61) compared RRA and RIA for atropine. These workers obtained preparations of receptor from rat brain and lyophilized them to a stable, dry form, They used the tritium-labeled quinuclidinyl benzilate at 35 Ci/mmol. The affinity constant was 0.48 nM, and by analysis of 25- xL serum samples they could obtain a sensitivity down to 1.25 ng/mL in serum. Nonspecific binding was again quite reasonable (4%) and a filtration-type separation was used. The d isomer of an atropine did not bind, and therefore, the cross-reaction of the d,l compound was 50% that of the ( isomer. For comparison they used RIA developed by the method of Virtanen et al, (37). The immunogen was an /-hyoscyamine-bovine serum albumin conjugate, but the antiserum was sensitive to both d,l and I isomers. Racemic tritium-labeled atropine was used as the radioligand. 

This isotherm model has been used successfully to accoimt for the adsorption behavior of numerous compounds, particularly (but not only) pairs of enantiomers on different chiral stationary phases. For example, Zhou et ah [28] foimd that the competitive isotherms of two homologous peptides, kallidin and bradyki-nine are well described by the bi-Langmuir model (see Figure 4.3). However, most examples of applications of the bi-Langmuir isotherm are found with enantiomers. lire N-benzoyl derivatives of several amino acids were separated on bovine serum albumin immobilized on silica [26]. Figure 4.25c compares the competitive isotherms measured by frontal analysis with the racemic (1 1) mixture of N-benzoyl-D and L-alanine, and with the single-component isotherms of these compounds determined by ECP [29]. Charton et al. foimd that the competitive adsorption isotherms of the enantiomers of ketoprofen on cellulose tris-(4-methyl benzoate) are well accounted for by a bi-Langmuir isotherm [30]. Fornstedt et al. obtained the same results for several jS-blockers (amino-alcohols) on immobilized Cel-7A, a protein [31,32]. 

TLC/immunostaining has been used to detect solaso-dine glycosides by separation of the compounds on a silica gel layer, transfer to a polyvinylidene difluoride membrane, and treatment of the membrane with sodium periodate solution followed by bovine serum albumin (BSA), resulting in a solasodine-BSA conjugate. Individual zones were stained by monoclonal antibody against solamargine. 

Lepri et al. investigated the chromatographic behavior of racemic dinitropyridyl, dinitrophenyl, dinitrobenzoyl, 9-fluorenylmethoxycarbonyl amino acids, tryptophanamides, lactic acid derivatives, and unusual enantiomers such as binaphthols on reversed phase TLC plates developed with aqueous-organic mobile phase containing bovine serum albumin (BSA) as chiral agent. More than 75 racemates has been separated in these experiments with planar chromatography using BSA in mobile phase. BSA showed enantioselectivity towards racemates with structures completely different from amino acids, their derivatives, and similar compounds such as hydroxy acids. 

Handes et al., 1974), acetylated cellulose (Hesse and Hagel, 1975), starch (Hess et al., 1978), pectic acid (Popova and Kratchanov, 1972), alginic acid (Kratchanov et al., 1969), alginic acid-silica gel (A.M. El Din Awad and O.M. El Din Awad, 1974) and agarose-supported bovine serum albumin (Stewart and Doherty, 1973) have all been used to separate various amino acids and other compounds. One report of the preferential absorption of L-phenylalanine by kaolin (Jackson, 1971) has been refuted (Bonner and Flores, 1974). 

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