Aminoacid-derivatised picolinato-oxidovanadium(IV) complexes: characterisation, speciation and ex vivo insulin-mimetic potential
| Autor: | Eugenio Garribba, Hossein Esbak, Dieter Rehder, Hiromu Sakurai, Éva A. Enyedy, Tamás Kiss, Yutaka Yoshikawa |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Stereochemistry
Substituent Biochemistry Diabetes Mellitus Experimental Inorganic Chemistry chemistry.chemical_compound Blood serum Biomimetics Amide medicine Adipocytes Moiety Animals Humans Hypoglycemic Agents Insulin Amino Acids Picolinic Acids Ternary complex chemistry.chemical_classification Chemistry Vanadium Phosphate Human serum albumin Amino acid Rats medicine.drug |
| Zdroj: | Journal of inorganic biochemistry. 103(4) |
| ISSN: | 1873-3344 |
| Popis: | The proligands PicMe-AaR (PicMe=methoxipicolyl-5-amide, where the amide substituent is an amino acid AaR=HisH, HisMe, IleH, IleMe, TrpH, TrpMe, HTyrEt, tBuTyrMe, HThrMe, tBuThrMe) and the complexes [VO(Pic-AaR)(2)] have been synthesised and characterised. A detailed EPR study of the VO(2+)/Pic-His systems in water revealed the predominance of the complex [VO(Pic-His)H(2)O] in the pH range 2-6, with tridentate coordination of Pic-His via the picolinate moiety and imidazole-Ndelta. Speciation analyses of the binary systems VO(2+)/Pic-Aa (Aa=His, Ile, Trp) and the ternary systems VO(2+)/Pic-Aa/B (Aa=His, Ile; B=citrate (cit), lactate (lac), phosphate) showed a predominance of the ternary complexes [VO(Pic-Aa)(cit/lac)] and [VO(Pic-Aa)(cit/lac)OH](-) in the physiological pH regime. If, in addition, human serum albumin (HAS) and apotransferrin (Tf) are present, with all of the low and high molecular mass constituents in their blood serum concentrations, about two thirds of VO(2+) is bound to the protein, while there is still a sizable amount of ternary complex [VO(Pic-Aa)(cit/lac)] present (about 1/4 for Pic-His and 1/3 for Pic-Ile) when the vanadium(IV) concentration is relatively high; at lower concentrations Tf is the predominant binder. Insulin-mimetic studies for VO(2+)/Pic-Aa (Aa=His, Ile, Tyr and Trp), based on a lipolysis assay with rat adipocytes, provided IC(50) values of 0.41(1) for VO(2+)/Pic-His and VO(2+)/Pic-Ile, which compares with 0.87(17) for VOSO(4). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect