Three phosphono-containing multidentate ligands were employed to synthesize quinquedentate binuclear copper complexes, [Cu2L2] (1–3) (H2L1 = diethyl(propane-1,3-diylbis(azanediyl))bis((2-hydroxyphenyl)methylene)bis(hydrogen phosphonate), H2L2 = diethyl(ethane-1,2-diylbis(azanediyl))bis((2-hydroxyphenyl)methylene)bis(hydrogen phosphonate), H2L3 = diethyl(hexane-1,6-diylbis(azanediyl))bis((2-hydroxyphenyl)methylene)bis(hydrogen phosphonate)), which were characterized by elemental analysis, IR, X-ray diffraction analysis, electrospray ionization mass spectra. Complexes 1 and 2 crystallized in the triclinic system with space group P. The speciation of the Cu–H2L1 system in aqueous solution was investigated by potentiometric pH titrations. The three dicopper complexes exhibited potent and almost the same inhibitory effects against protein tyrosine phosphatase 1B (PTP1B) and T-cell protein tyrosine phosphatase (TCPTP) with IC50 of 0.16–0.24 μM, about 10-fold stronger inhibition than against Src homology phosphatase 1 (SHP-1), 30-fold than against Src homology phosphatase 2 (SHP-2) and more than 100-fold than against megakaryocyte protein-tyrosine phosphatase 2 (PTP-MEG2). Fluorescence titrations revealed complex 1 bond to the five PTPs with molar ratio of 1 : 1 and binding constants of 1.62 × 106, 3.09 × 106, 1.95 × 105, 2.24 × 105, 1.55 × 104 M−1 for PTP1B, TCPTP, SHP-1, SHP-2 and PTP-MEG2, respectively, consistent with the inhibitory abilities from IC50 and Ki values. Also, the three copper complexes could inhibit phosphatase activity of cell extracts from C6 rat glioma cells. The results suggested the structures of copper complexes influence selectivity over different PTPs.
采用三种含
磷多叉
配体合成了五价双核
铜配合物 [Cu2
L2] (1-3)(H2L1 =
二乙基(
丙烷-1,3-二基双(偶氮二基))双((2-羟基苯基)亚甲基)双(
膦酸氢盐)、H2
L2 =
二乙基(
乙烷-1、H2L3=(己烷-1,6-二基双(偶氮二基))双((2-羟基苯基)亚甲基)双(
膦酸氢盐)
二乙基),它们通过元素分析、红外光谱、X 射线衍射分析和电喷雾质谱进行了表征。通过电位 pH 滴定法研究了 Cu-H2L1 体系在
水溶液中的形态。这三种二
氯化
铜复合物对蛋白
酪氨酸磷酸酶 1B (
PTP1B) 和 T 细胞蛋白
酪氨酸磷酸酶 (
TCPTP) 具有强效且几乎相同的抑制作用,IC50 为 0.16-0.24 μM,抑制作用比 Src 同源
磷酸酶 1 (SHP-1) 强 10 倍,比 Src 同源
磷酸酶 2 (SHP-2) 强 30 倍,比巨核细胞蛋白-
酪氨酸磷酸酶 2 (
PTP-
MEG2) 强 100 倍以上。荧光滴定显示,复合物 1 与五种
PTP 的摩尔比为 1 :1,与
PTP1B、
TCPTP、SHP-1、SHP-2 和
PTP-
MEG2 的结合常数分别为 1.62 × 106、3.09 × 106、1.95 × 105、2.24 × 105、1.55 × 104 M-1,与 IC50 和 Ki 值的抑制能力一致。此外,这三种
铜复合物还能抑制 C6 大鼠胶质瘤细胞
提取物的
磷酸酶活性。结果表明,
铜复合物的结构会影响对不同
PTPs 的选择性。