Department of Biological Science and Technology, National Chiao Tung University, 75 Bo-Ai Street, Hsinchu 300, Taiwan.
Dalton Trans. 2011 May 14;40(18):5018-25. doi: 10.1039/c1dt10033e. Epub 2011 Mar 31.
In this study, we have developed two new L-tryptophan based contrast agents Gd(Try-TTDA)(H(2)O) and Gd(Try-ac-DOTA)(H(2)O). Upon addition of Cu(II) to Gd(Try-TTDA)(H(2)O), significant increases in the relaxivity (r(1)) and hydration number of Gd(Try-TTDA)(H(2)O) were observed. However, it only induced a minute increase in the relaxivity (r(1)) in the case of Gd(Try-ac-DOTA)(H(2)O). Furthermore, the interaction of Cu(II) with the indole ring of Gd(III) complexes was explored by measuring the intrinsic fluorescence of the tryptophan of the Gd(III) complex. With the addition of one equivalent of Cu(II) to Gd(Try-TTDA)(H(2)O) the indole fluorescence was completely quenched. Moreover, the Gd(Try-TTDA)(H(2)O) complex shows excellent selectivity towards Cu(II) over other metal ions (Cu(II) > La(III) > Mg(II)). Importantly, the significant signal intensity (2073 ± 67) for in vitro MR imaging using Gd(Try-TTDA)(H(2)O) in the presence of Cu(II) implicates that this new smart contrast agent (Gd(Try-TTDA)(H(2)O)) can serve as a Cu(II) sensor for MR imaging.
在这项研究中，我们开发了两种基于 L-色氨酸的新型造影剂 [Gd(Try-TTDA)(H2O)]2- 和 [Gd(Try-ac-DOTA)(H2O)]-。向 [Gd(Try-TTDA)(H2O)]2- 中加入 Cu(II)后，观察到 [Gd(Try-TTDA)(H2O)]2- 的弛豫率 (r1) 和水合数显著增加。然而，在 [Gd(Try-ac-DOTA)(H2O)]-的情况下，仅诱导了弛豫率 (r1) 的微小增加。此外，通过测量 Gd(III)配合物中色氨酸的本征荧光，研究了 Cu(II)与 Gd(III)配合物中吲哚环的相互作用。向 [Gd(Try-TTDA)(H2O)]2- 中加入一当量的 Cu(II)，吲哚荧光完全猝灭。此外，[Gd(Try-TTDA)(H2O)]2- 配合物对 Cu(II)表现出优于其他金属离子 (Cu(II) > La(III) > Mg(II)) 的优异选择性。重要的是，在存在 Cu(II)的情况下，使用 [Gd(Try-TTDA)(H2O)]2- 进行体外磁共振成像的信号强度显著增加（2073 ± 67），表明这种新型智能造影剂 ([Gd(Try-TTDA)(H2O)]2-)可以作为磁共振成像的 Cu(II)传感器。
