Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, United States.
J Inorg Biochem. 2009 Dec;103(12):1652-7. doi: 10.1016/j.jinorgbio.2009.09.006. Epub 2009 Sep 20.
The coordination chemistry of bisphosphonates with Yb(3+) was investigated to evaluate the potential of the UV-vis based detection method using the Yb(3+)-pyrocatechol complexation reaction as a sensor for bisphosphonates. The complexation chemistry of Yb(3+) with phosphate and ATP analogs was previously described (E. Gaidamauskas, K. Saejueng, A.A. Holder, S. Bharuah, B.A. Kashemirov, D.C. Crans, C.E. McKenna, J. Biol. Inorg. Chem. 13 (2008) 1291-1299), and we here studied the complexation chemistry of bisphosphonates in this system. The spectrophotometric assay yields direct evidence for formation of a 4:3 metal to ligand complex at neutral pH. Direct evidence for Yb(3+):methylenebis(phosphonate) complexes with 1:1 and 1:2 stoichiometry was also obtained by potentiometry at acidic and basic pH. Direct evidence for complex formation was obtained using (1)H NMR spectroscopy although the stoichiometry was not accessed at neutral pH. Our results suggest that the spectroscopic observation of the YbPV complex can be used to conveniently measure concentrations of bisphosphonates down to 2-3 microM.
研究了双膦酸盐与 Yb(3+) 的配位化学，以评估使用 Yb(3+)-邻苯二酚络合反应作为双膦酸盐传感器的基于紫外-可见的检测方法的潜力。先前已经描述了 Yb(3+)与磷酸盐和 ATP 类似物的络合化学（E. Gaidamauskas、K. Saejueng、A.A. Holder、S. Bharuah、B.A. Kashemirov、D.C. Crans、C.E. McKenna、J. Biol. Inorg. Chem. 13 (2008) 1291-1299），我们在这里研究了该体系中双膦酸盐的络合化学。分光光度测定法在中性 pH 下直接证明了 4:3 金属与配体络合物的形成。通过在酸性和碱性 pH 下的电位法也获得了亚甲基双膦酸盐与 Yb(3+)的 1:1 和 1:2 化学计量比的直接证据。尽管在中性 pH 下无法获得化学计量比，但使用（1）H NMR 光谱学也获得了络合形成的直接证据。我们的结果表明，可以使用 YbPV 络合物的光谱观察来方便地测量低至 2-3 μM 的双膦酸盐浓度。
