title: Designing of the centers for adsorption of bile acids on a silica surface.
abstract: Silicas chemically modified with attached aminopropyl, imidazolyl, and trimethylsilyl groups, with adsorptive and coordinative grafted hemin were synthesized. Adsorption of some bile acids on the surface of hydroxylated silica, synthesized siliceous adsorbents and cholestyramine has been studied. It was found that the main contribution to the total adsorption is caused by electrostatic attraction between anions of bile acids and positively charged sites of the surface of modified silica and also by dispersion interactions between steroid skeleton of bile acids and functional groups of modified silicon dioxides. It was established that the kinetic parameters of adsorption and adsorptive capacity for all investigated siliceous adsorbents exceed similar characteristics for cholestyramine. The best of synthesized adsorbents is hemin-containing adsorbent IX, and the sequence of increase in its adsorptive capacity in relation to bile acids corresponds to the following series: I < III < II, IV < VI < V < VIII < VII < IX.
authors.affiliation: Institute of Surface Chemistry, National Academy of Sciences of Ukraine, ul. Generala Naumova 17, Kiev 03680, Ukraine. v-bel@mail.kar.net
authors.forename: Lyudmila A
authors.initials: LA
authors.lastname: Belyakova
authors.forename: Liliya N
authors.initials: LN
authors.lastname: Besarab
authors.forename: Nadiya V
authors.initials: NV
authors.lastname: Roik
authors.forename: Diana Y
authors.initials: DY
authors.lastname: Lyashenko
authors.forename: Nataliya N
authors.initials: NN
authors.lastname: Vlasova
authors.forename: Lyudmila P
authors.initials: LP
authors.lastname: Golovkova
authors.forename: Aleksey A
authors.initials: AA
authors.lastname: Chuiko
mesh_terms: D000327:Adsorption; D000838:Anions; D001647:Bile Acids and Salts / Q000737:chemistry*; D001665:Binding Sites; D002792:Cholestyramine Resin / Q000737:chemistry; D006427:Hemin / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006900:Hydroxylation; D007093:Imidazoles / Q000737:chemistry; D007700:Kinetics; D016062:Porosity; D011437:Propylamines / Q000737:chemistry; D012822:Silicon Dioxide / Q000138:chemical synthesis*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity; D013256:Steroids / Q000737:chemistry / Q000378:metabolism; D013499:Surface Properties; D014297:Trimethylsilyl Compounds / Q000737:chemistry
chemical_list: D000838:Anions; D001647:Bile Acids and Salts; D007093:Imidazoles; D011437:Propylamines; D013256:Steroids; D014297:Trimethylsilyl Compounds; D002792:Cholestyramine Resin; D006427:Hemin; D012822:Silicon Dioxide