Al Salmi Iman K, Al Mamari Hamad H, Robertson Craig C, Handa Makoto, Tavajohi Shohreh, Brookfield Adam, McInnes Eric J L, Hayashi Yoshihito, Moghadam Ebrahim S, Shongwe Musa S
Department of Chemistry, College of Science, Sultan Qaboos University, PO Box 36, Al-Khod, 123 Muscat, Sultanate of Oman.
School of Mathematical and Physical Sciences, University of Sheffield, Sheffield S3 7HF, UK.
ACS Omega. 2025 May 28;10(22):23440-23460. doi: 10.1021/acsomega.5c01984. eCollection 2025 Jun 10.
Single-crystal X-ray structures of hydrated di-(2-pyridyl) ketone 4,4-dimethyl-3-thiosemicarbazone (HDpk44mT·HO), the ternary ionic copper-(II) complexes [Cu-(Dpk-H-44mT)-(phen)]-(ClO)·1-(1/2)-MeOH (1-(1/2)-MeOH) and [Cu-(Dpk44mT)-(phen)]-ClO () (Dpk-H-44mT = zwitterionic) form of HDpk44mT; phen = 1,10-phenanthroline and the molecular dioxovanadium-(V) complex [VO(Dpk44mT)] () have been determined. Additionally, the solution structures of HDpk44mT·HO and complex have been elucidated with the aid of NMR spectroscopic techniques. Coordination compounds 1-(1/2)-MeOH, and represent extremely rare examples of thiosemicarbazone complexes of their specific kind possessing a moiety. Under slightly acidic conditions, complex 1-(1/2)-MeOH is produced with the thiosemicarbazone ligand occurring in the zwitterionic thio-enolate form, but readily converts to complex in basic medium. In the crystal lattice, these two copper-(II) complexes show vastly different patterns of π-π stacking interactions. However, they have in common the ligand-imposed distorted square-pyramidal coordination geometry exhibiting a tetragonally induced disparity between the distances of the axial-equatorial Cu-N bonds. X-band EPR spectroscopy demonstrated retention of the coordination sphere ( > > 2.00; > ) in frozen solution. The crystallographic asymmetric unit of [VO(Dpk44mT)] comprises two discrete molecules, one of which exhibits π-π stacking interactions. Their coordination geometry at the vanadium-(V) center is severely distorted square pyramidal. Complexes 1-(1/2)-MeOH, and are electroactive with reduction potentials lying within the biologically accessible redox potential window. While the copper-(II) complexes are highly efficacious as antiproliferative agents against the cancer cell lines HeLa and MCF-7, the main drawback is the lack of selectivity over the normal cell line MCF-10A. In sharp contrast, [VO(Dpk44mT)] is specifically and selectively potent toward MCF-7 over HeLa and MCF-10A cells, and may provide impetus for further antitumor investigations.
已测定了水合二（2 - 吡啶基）酮4,4 - 二甲基 - 3 - 硫代半卡巴腙（HDpk44mT·H₂O）、三元离子型铜（II）配合物[Cu-(Dpk-H-44mT)-(phen)]-(ClO₄)·1-(1/2)-MeOH（1-(1/2)-MeOH）和[Cu-(Dpk44mT)-(phen)]-ClO₄（）（Dpk-H-44mT为HDpk44mT的两性离子形式；phen = 1,10 - 菲咯啉）以及分子型二氧钒（V）配合物[VO(Dpk44mT)]（）的单晶X射线结构。此外，借助核磁共振光谱技术阐明了HDpk44mT·H₂O和配合物的溶液结构。配合物1-(1/2)-MeOH、和代表了具有特定基团的硫代半卡巴腙配合物中极为罕见的例子。在微酸性条件下，生成配合物1-(1/2)-MeOH，硫代半卡巴腙配体以两性离子硫代烯醇盐形式存在，但在碱性介质中容易转化为配合物。在晶格中，这两种铜（II）配合物表现出截然不同的π - π堆积相互作用模式。然而，它们的共同之处在于配体导致的扭曲四方锥配位几何结构，在轴向 - 赤道面Cu - N键距离之间呈现出四方诱导的差异。X波段电子顺磁共振光谱表明在冷冻溶液中配位球得以保留（> > 2.00；> ）。[VO(Dpk44mT)]的晶体学不对称单元包含两个离散分子，其中一个表现出π - π堆积相互作用。它们在钒（V）中心的配位几何结构严重扭曲为四方锥。配合物1-(1/2)-MeOH、和具有电活性，还原电位处于生物可及的氧化还原电位窗口内。虽然铜（II）配合物作为抗增殖剂对癌细胞系HeLa和MCF - 7具有高效性，但其主要缺点是对正常细胞系MCF - 10A缺乏选择性。与之形成鲜明对比的是，[VO(Dpk44mT)]对MCF - 7细胞比对HeLa和MCF - 10A细胞具有特异性和选择性的强效作用，可能为进一步的抗肿瘤研究提供动力。
