In this study, we have developed two new L-tryptophan based contrast agents [Gd(Try-TTDA)(H2O)]2â and [Gd(Try-ac-DOTA)(H2O)]â. Upon addition of Cu(II) to [Gd(Try-TTDA)(H2O)]2â, significant increases in the relaxivity (r1) and hydration number of [Gd(Try-TTDA)(H2O)]2â were observed. However, it only induced a minute increase in the relaxivity (r1) in the case of [Gd(Try-ac-DOTA)(H2O)]â. 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)(H2O)]2â the indole fluorescence was completely quenched. Moreover, the [Gd(Try-TTDA)(H2O)]2â 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)(H2O)]2â in the presence of Cu(II) implicates that this new smart contrast agent ([Gd(Try-TTDA)(H2O)]2â) can serve as a Cu(II) sensor for MR imaging.
在这项研究中,我们开发了两种新的基于
L-色氨酸的造影剂[Gd(Try-
TTDA)(
H2O)]2â和[Gd(Try-ac-DOTA)( )]â。在[Gd(Try-
TTDA)( )]2â中加入
铜(II)后,[Gd(Try-
TTDA)( )]2â的弛豫度(r1)和
水合数显著增加。然而,在[Gd(Try-ac-DOTA)( )]â的情况下,它只引起了弛豫度(r1)的微小增加。此外,通过测量 Gd(III)络合物色
氨酸的本征荧光,还探索了 Cu(II)与 Gd(III)络合物
吲哚环的相互作用。在[Gd(Try-
TTDA)( )]2â中加入一个当量的 Cu(II)后,
吲哚荧光被完全熄灭。此外,[Gd(Try-
TTDA)( )]2â 复合物对 Cu(II)的选择性优于其他
金属离子(Cu(II) > La(III) > Mg(II))。重要的是,使用[Gd(Try-
TTDA)( )]2â 在 Cu(II)存在下进行体外磁共振成像时,信号强度(2073 ± 67)显著,这表明这种新型智能造影剂([Gd(Try-
TTDA)( )]2â)可用作磁共振成像的 Cu(II)传感器。