Study On Synthesis, Characterization And Properties Of Vanadium Complexes

Vanadium has been proposed and accepted to be an essential trace element in human body. The insulin-like effect of Inorganic vanadate and vanadium complexes was the most remarkable finding and a few of vanadium compounds have been used into clinical trials. Inorganic vanadate has many drawbacks, such as: toxicity, small fat-solubility, low bioavailability and dose requirements, so vanadium complex draws hot attention and becomes a hot research. In order to reduce the toxicity and improve the absorption and efficacy of the vanadium, we should select the appropriate ligands.In this paper, four new vanadium (V) hydroxylamido complexes with several biological ligands were synthesized. Their structures were also characterized. The stability, the fat-solubility of the complexes and PTP1B protein tyrosinase activity experiments were studied. The main work of the research as follows:1. Four new vanadium (V) hydroxylamido complexes with ligands including leucine, hisdine, Phenylalanine, o-aminobenzoic acid were synthesized. The basic compositions of the complexes were determined by the elemental analysis, thermogravimetric analysis and the IR, UV spectra respectively. Moreover, we carried out single crystal diffraction analysis of vanadium (V) hydroxylamido complex with leucine, determined its crystal structure, and provided reference values for the study of crystal structure of vanadium complexes.2. A series performance of new synthesized complexes was tested, including: stability, fat-solubility, activity test. Stability: the stability of the four new vanadium complexes at three different pH values of the solution was tested. Fat-solubility study: (determination of the partition coefficient): The absorbance of vanadium complexes dissolved in a Krebs-Ringer bicarbonate (KRB) buffer (pH = 7.4) / n-octanol system were determined respectively, and its partition coefficient was calculated in accordance with formula. The results showed that, the new complexes had certain stability and certain solubility which provided prerequisite for new potential drugs. Activity test: An initial model experiment of protein tyrosine Phosphatase PTP1B was carried out. The results showed that, inhibition rate of the new complexes to PTP1B were less than 50% with a low selectivity and activity on the PTP1B. We will test the other activities of the new synthesized vanadium complexes as vanadium's an essential trace element to the organism. Because of time constraints, this part of the study was still under study.A series of work conducted, accumulated a number of basic researches for the vanadium complexes as insulin mimics and enriched the vanadium contenting bioinorganic chemistry at the same time.