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Starting from 5-sulfamoylisatins, 6-sulfamoyl-4-quinolinecarboxylic acids and 2-methyl-6-sulfamoylquinoline-3,4-dicarboxylic acids were prepared by the Pfitzinger reaction. These acids and diacids were then converted to the corresponding amide and imide libraries. A patent based on these new combinatorial chemical libraries has been applied for. All the newly synthesized compounds are crystalline substances that were purified by recrystallization from suitable solvents and characterized primarily by 1H NMR, 13C NMR, and mass spectrometry.

3,3-Dichloro-5-(4-methylpiperidinosulfonyl)-2-indolinone (3) and 5-sulfamoylisatins 4 have been synthesized from 5-chlorosulfonyl-3,3-dichloro-2-indolinone (1). Compounds 4 are promising scaffolds for the solid- and liquid-phase syntheses of new combinatorial libraries of various heterocycles. Thus, the reactions of 4 with 1,2-diamines, such as o-phenylenediamine (5) and aminoguanidine hydrochloride (6), 1,2-diaminoimidazoles (9), and thiosemicarbazide led, respectively, to new heterocycles 7 and 8 and new combinatorial libraries of triazinoindoles 10 and 15. Chemsets 4, 10, and 15 were isolated as crystalline solids that were purified by recrystallization from a suitable solvent and characterized by spectroscopic methods.

An approach to the analysis of isotherms of cooperative binding is developed that allows to calculate approximately affinity profiles, i.e. dependencies of binding constants on binding densities. The comparison of the affinity profiles of the interactions of Ca2+ and Sr2+ ions with sodium pectate as well as sodium alginates with the different content of the blocks of alpha-L-guluronic acid residues (GG-blocks) and blocks of mixed composition showed that (1) pectate has higher affinity to both ions as compared with alginates; (2) the affinity of pectate to Ca2+ ions is comparable to its affinity to Sr2+ ions but in the case of Ca2+ ions the maximum of the affinity profile falls on the substantially lesser value of the binding density in comparison to Sr2+ ions that seems to be unfavorable from the standpoint of the use of this polyuronide in preventive or medicinal nutrition; (3) the affinity of both alginates to Sr2+ ions at relatively low binding densities exceeds their affinity to Ca2+ ions; (4) the affinity of alginates to Sr2+ ions increases with the increase in the content of GG-blocks, whereas the affinity to Ca2+ ions practically does not depend on the composition of the alginate; (5) the maximum binding density of Sr2+ ions to the alginates approximately corresponds to the content of GG-blocks. These results corroborate the practice of the use of alginates rich in residues of alpha-L-guluronic acid for the removal of radioactive strontium from the digestive tract. The binding constants of Pb2+ ions to pectate over a wide range of binding densities are more than an order of magnitude greater than those of alkali-earth metal ions.

Investigation has been conducted using equilibrium dialysis on the sorption of flavor compounds (FC) in solutions of low- and high-esterified pectinates (LEP and HEP, respectively). The compounds include 2-acetyl pyridine, 2,3-diethyl pyrazine, 2-acetyl thiophene and some normal 2-ketones. A method of direct gas chromatographic analysis has been developed for the determination of the FC in aqueous solutions at concentrations as low as 10(-3)% v/v. Additional information was obtained by the analysis of circular dichroism (CD) and apparent molar heat capacity. The results indicate: (1) In LEP solutions, sorption of normal aliphatic 2-ketones with chain length greater than C6 presumably proceeds via van der Waals interactions between alkyl groups of the 2-ketone and hydrophobic regions of the pectinate. The sorption increases with increased alkyl chain length. The Gibbs energy of the methylene group transferring from the solvent to the LEP solution is found to be 1.8 kJ/mol for 2-ketones at C7-C9. (2) In acidic media, binding of heterocyclic FC with pectinates mostly proceeds via hydrogen bonding involving the hydrogen atoms in undissociated carboxyl groups in the pectinate macromolecules. It can also be affected by the self-association of the pectinate macromolecules, depending on pH and pectinate concentration. (3) Under neutral conditions, the presence of Mg2+, Ca2 and Zn2+ ions or the formation of the calcium-pectinate gel network has little effect on the sorption of 2-ketones with the LEP. However, in acidic media, metal ions inhibit the sorption of FC through hydrogen bonding. The sorption of 2-octanone in acidic media depends extremely on Ca++ concentration by the correlationship with changes in the structure of LEP solutions in terms of apparent molar heat capacity.