Departamento de Química-Centro de Síntesis Química de La Rioja (CISQ), Universidad de La Rioja, 26006, Logroño, Spain.
Lung Cancer and Respiratory Diseases Unit (CIBIR), Fundación Rioja Salud, 26006, Logroño, Spain.
Dalton Trans. 2023 Sep 13;52(35):12390-12403. doi: 10.1039/d3dt01759a.
Given the widely recognized bioactivity of 2-arylbenzothiazoles against tumor cells, we have designed a new family of luminescent heteroleptic pentafluorophenyl-bis(2-phenylbenzothiazolyl) Pt derivatives, -[Pt(pbt)(CF)L] ( = 1, 0) [L = 4-Mepy 1, 4-pyridylbenzothiazole (pybt) 2, 4,4'-bipyridine (4,4'-bpy) 3, 1,2-bis-(4-pyridyl)ethylene (bpe) 4 (/ ratio: 90/10), 1,4-bis-(pyridyl)butadiyne (bpyb) 5, trifluoroacetate (OCOCF) 6] and a dinuclear complex {Pt(pbt)(CF)}(μ-bpyb)7, in which the ligand to the metalated C-(pbt) was varied to modify the optical properties and lipophilicity. Their photophysical properties were systematically studied through experimental and theoretical investigations, which were strongly dependent on the identity of the N-bonded ligand. Thus, complexes 1, 3 and 6 display, in different media, emission from the triplet excited states of primarily intraligand ILCT nature localized on the pbt ligand, while the emissions of 2, 5 and 7 were ascribed to a mixture of close IL'(N donor)/ILCT(pbt) excited states, as supported by lifetime measurements and theoretical calculations. Irradiation of the initial / mixture of 4 (15 min) led to a steady state composed of roughly 1 : 1.15 ( : ) and this complex was not emissive at room temperature due to an enhanced intramolecular to isomerization process of the 1,2-bis-(4-pyridyl)ethylene ligand. Complexes 1-3 and 6 showed excellent quantum yields for the generation of singlet oxygen in aerated MeCN solution with the values of (O) ranging from 0.66 to 0.86 using phenalenone as a reference. Cationic complexes 1-3 exhibited remarkable efficacy in the nanomolar range against A549 (lung carcinoma) and HeLa (cervix carcinoma) cell lines with notable selectivity relative to the non-tumorigenic BEAS-2B (bronchial epithelium) cells. In the A549 cell line, the neutral complex 6 showed low cytotoxicity (IC: 29.40 μM) and high photocytotoxicity (IC: 5.75) when cells were irradiated with blue light for 15 min. These complexes do not show evidence of DNA interaction.
鉴于 2-芳基苯并噻唑对肿瘤细胞具有广泛认可的生物活性，我们设计了一系列新型发光杂化五氟苯基-双（2-苯基苯并噻唑基）Pt 衍生物，-[Pt(pbt)(CF)L]（=1、0）[L=4-Mepy 1、4-吡啶基苯并噻唑（pybt）2、4,4'-联吡啶（4,4'-bpy）3、1,2-双（4-吡啶基）乙烯（bpe）4（/ 比：90/10）、1,4-双（吡啶基）丁二炔（bpyb）5、三氟乙酸盐（OCOCF）6]和双核配合物[{Pt(pbt)(CF)}（μ-bpyb）]（PF）7，其中配体与金属化 C-（pbt）的结合方式不同，以改变光学性质和亲脂性。通过实验和理论研究系统研究了它们的光物理性质，这些性质强烈依赖于 N-键合配体的身份。因此，配合物 1、3 和 6 在不同介质中显示出主要来自配体 pbt 上的三重激发态的 ILCT 性质的配体内发射，而 2、5 和 7 的发射归因于紧密的 IL'（N 供体）/ILCT（pbt）激发态的混合物，如寿命测量和理论计算所支持。初始混合物 4（15 分钟）的辐照导致大致 1：1.15（：）的稳定状态，由于 1,2-双（4-吡啶基）乙烯配体的增强分子内 到 异构化过程，该复合物在室温下不发光。配合物 1-3 和 6 在有氧 MeCN 溶液中产生单线态氧的量子产率非常高，使用 phenalenone 作为参考时，值为（O）为 0.66 至 0.86。阳离子配合物 1-3 对 A549（肺癌）和 HeLa（宫颈癌）细胞系表现出优异的纳摩尔范围内的疗效，与非致瘤性 BEAS-2B（支气管上皮）细胞相比具有显著的选择性。在 A549 细胞系中，中性配合物 6 在细胞用蓝光照射 15 分钟时显示出低细胞毒性（IC：29.40 μM）和高光细胞毒性（IC：5.75）。这些配合物没有证据表明与 DNA 相互作用。
