生物必需过渡金属离子与天然螯合剂的光活性金属络合物作为癌症光动力疗法（PDT）的光细胞毒性剂越来越受到人们的关注。我们报道了六种新的钴(III)配合物，其具有混合配体配方[Co(B)2(L)](ClO4)2 (Co1-Co6)，其中B代表N,N-供体α-二亚胺配体，即、菲咯啉（phen；Co1、Co2）、联吡啶并[3,2-d:2',3'-f]喹喔啉（dpq；Co3、Co4）和联吡啶[3,2-a:2',3'- c]吩嗪 (dppz; Co5, Co6)，L 是天然黄酮类化合物白杨素 (chry; Co1, Co3, Co5) 和水飞蓟宾 (sili; Co2, Co4, Co6) 的单阴离子形式。配合物在 500-700 nm 范围内显示出 d-d 吸收带，并在溶液中表现出优异的暗稳定性和光稳定性。细胞毒性研究表明，Co5 和 Co6 在可见光 (400-700 nm) 照射下对宫颈 (HeLa) 和肺癌 (A549) 癌细胞具有显着活性，具有低微摩尔 IC50 值（2.3-3.4 µM，光毒性指数 ~ 15-30）。该复合物对正常 HPL1D 肺上皮细胞的毒性显着降低。流式细胞术分析揭示了复合物在辐射时引发的细胞损伤的凋亡模式。 ROS 生成测定表明单线态氧参与光照射时的细胞死亡机制。总体而言，配合物 Co5 和 Co6 与联吡啶吩嗪和类黄酮配体是癌症 PDT 应用的潜在候选者。© 2024 Wiley‐VCH GmbH。

Photoactive metal complexes of bioessential transition metal ions with natural chelators are gaining interest as photocytotoxic agents for cancer photodynamic therapy (PDT). We report six new cobalt(III) complexes with a mixed-ligand formulation [Co(B)2(L)](ClO4)2 (Co1-Co6), where B represents a N,N-donor α-diimine ligand, namely, phenanthroline (phen; Co1, Co2), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq; Co3, Co4), and dipyrido[3,2-a:2',3'-c]phenazine (dppz; Co5, Co6), and L is the monoanionic form of the naturally occurring flavonoids chrysin (chry; Co1, Co3, Co5) and silibinin (sili; Co2, Co4, Co6). Complexes displayed a d-d absorption band within 500-700 nm and exhibited excellent dark and photostability in solution. Cytotoxicity studies indicated significant activity of Co5 and Co6 against cervical (HeLa) and lung (A549) cancer cells under visible light (400-700 nm) irradiation giving low micromolar IC50 values (2.3-3.4 µM, phototoxicity index ~ 15-30). The complexes demonstrated notably low toxicity against normal HPL1D lung epithelial cells. Flow cytometry assay revealed an apoptotic mode of cell damage triggered by the complexes when irradiated. ROS generation assay indicated the involvement of singlet oxygen species in the cell death mechanism when irradiated with light. Overall, complexes Co5 and Co6 with coordinated dipyridophenazine and flavonoid ligands are potential candidates for cancer PDT applications.© 2024 Wiley‐VCH GmbH.