title: [1H-NMR analysis of the heteroassociation of caffeine with the antibiotic actinocyl-bis(3-dimethylaminopropylamine) in aqueous solution].
abstract: The heteroassociation of caffeine (CAF) and the synthetic antibiotic actinocyl-bis(3-dimethylaminopropylamine) (ACT) was studied in aqueous solution by one- and two-dimensional 1H NMR spectroscopy at 500 MHz. The equilibrium reaction constants, thermodynamic parameters (delta H and delta S) of ACT heteroassociation with CAF, the limiting values of proton chemical shifts of their molecules in the heteroassociation complex, and the spatial structure of the ACT-CAF complex were determined from the experimental dependences of proton chemical shifts of the aromatic molecules on concentration and temperature. The parameters of CAF heteroassociation with the phenoxazone antibiotic actinomycin D and its synthetic analogue ACT were comparatively analyzed and conclusions were made on the crucial role of stacking interactions of the chromophores of CAF and the phenoxazone antibiotics in the formation of the heterocomplexes in aqueous solution.
authors.affiliation: Department of Physics, Sevastopol State Technical University, Streletskaya balka, Sevastopol, Crimea, 99053 Ukraine. veselkov@sevgtu.sebastopol.ua
authors.forename: A N
authors.initials: AN
authors.lastname: Veselkov
authors.forename: A O
authors.initials: AO
authors.lastname: Lantushenko
authors.forename: D A
authors.initials: DA
authors.lastname: Veselkov
authors.forename: D B
authors.initials: DB
authors.lastname: Davies
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry*; D002110:Caffeine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010078:Oxazines / Q000737:chemistry*; D011437:Propylamines / Q000737:chemistry*; D012996:Solutions; D013816:Thermodynamics; D014867:Water
chemical_list: D000970:Antineoplastic Agents; D010078:Oxazines; D011437:Propylamines; D012996:Solutions; C465425:actinocyl-bis(3-dimethylaminopropylamine); D014867:Water; D002110:Caffeine