Interactions of Indole Derivatives with ß-Cyclodextrin: A Quantitative Structure-Property Relationship Study.

Retention factors for 31 indole derivatives, most of them with auxin activity, were determined by high-performance liquid chromatography, using bonded ß-cyclodextrin as a stationary phase. A three-parameter QSPR (quantitative structure-property relationship) model, based on physico-chemical and structural descriptors was derived, which accounted for about 98% variations in the retention factors. The model suggests that the indole nucleus occupies the relatively apolar cavity of ß-cyclodextrin while the carboxyl group of the indole -3-carboxylic acids makes hydrogen bonds with the hydroxyl groups of ß-cyclodextrin. The length and flexibility of the side chain containing carboxyl group strongly affect the binding of these compounds to ß-cyclodextrin. Non-acidic derivatives, unlike the indole-3-carboxylic acids, are poorly retained on the column. A reasonably well correlation was found between the retention factors of the indole-3-acetic acids and their relative binding affinities for human serum albumin, a carrier protein in the blood plasma. A less satisfactory correlation was obtained when the retention factors of the indole derivatives were compared with their affinities for auxin-binding protein 1, a plant auxin receptor.

Molecular recognition of indole derivatives by polymers imprinted with indole-3-acetic acid: a QSPR study.

Three molecularly imprinted polymers (MIPs) were prepared using the phytohormone indole-3-acetic acid (IAA) as a template molecule, 4-vinylpyridine (MIP-1 and MIP-2) or N,N-dimethylaminoethyl methacrylate (MIP-3) as functional monomers, ethylenglycol dimethacrylate as a cross linker and acetonitrile (MIP-1), a methanol-water mixture (MIP-2) or chloroform (MIP-3) as porogens. Retention factors for IAA and 29 indole derivatives were determined by high-performance liquid chromatography, using the molecularly imprinted polymers as stationary phases and acetonitrile as an eluent. High correlations between selectivity factors of above mentioned polymers indicate that their retention mechanisms are basically the same. A quantitative structure-property relationships analysis revealed that the presence of the terminal carboxyl group on the 3-side chain plays an essential role in the binding of the indole derivatives to the polymers. The derivatives without the carboxyl group exhibit a drastically lower affinity toward the polymers. Another factor which favors the binding is electronic density of indole nucleus. Substituents with electro-withdrawing properties enhance the binding, while electro-donating substituents have the opposite effect. The length of the 3-side chain also affects the binding. Indole-3-carboxylic acid having the carboxyl group directly attached to the ring as well as the derivatives whose side chain is longer than that of IAA bind to the polymers with a lower affinity.

Growth characteristics of channel catfish ovary cells-influence of glucose and glutamine.

The growth characteristics and influence of glucose and glutamine on the growth and maintenance of channel catfish ovary (CCO) cells were investigated. Besides glutamine, amino acids threonine, arginine, methionine and serine were found to be essential for CCO cell growth. In the glucose-free medium, glutamine is utilized as energy source and no cell growth limitation was observed. However, the lack of glutamine in culture medium did not stimulate CCO cells to efficient glucose consumption. When both glucose and glutamine were deficient, cell growth was also observed suggesting no rigorous nutritional requirements. Obtained results are useful for further understanding of culture processes using CCO cells.