Cellular uptake and remarkable photocytotoxicity of pyrenylter pyridine oxovanadium(IV) complexes of dipyridophenazine bases

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• 作者：Bhabatosh Banik^a ; Kumar Somyajit^b ; Debasis Koley^c ; Ganesh Nagaraju^b ; ^{nganesh@biochem.iisc.ernet.in} ; Akhil R. Chakravarty^a ; ^{arc@ipc.iisc.ernet.in}
• 关键词：Oxovanadium(IV) complexes ; Dipyridophenazine bases ; DNA photocleavage ; Photocytotoxicity ; Structure&ndash ; activity relationship
• 刊名：Inorganica Chimica Acta
• 出版年：2012
• 出版时间：1 December, 2012
• 年：2012
• 卷：393
• 期：Complete
• 页码：284-293
• 全文大小：896 K

文摘

Pyrenylterpyridine (pytpy) oxovanadium(IV) complexes [VO(pytpy)(L)]Cl₂ (1-6) of the dipyridophenazine bases (L), viz., dipyrido-6,7,8,9-tetrahydrophenazine (dpqC in 1), dipyrido[3,2-a:2¡ä,3¡ä-c]phenazine-2-carboxylic acid (dppzc in 2), dipyrido[3,2-a:2¡ä,3¡ä-c]phenazine-11-sulfonic acid (dppzs in 3), 7-aminodipyrido[3,2-a:2¡ä,3¡ä-c]phenazine (dppza in 4), benzo-[i]dipyrido[3,2-a:2¡ä,3¡ä-c]phenazine (dppn in 5) and dipyrido[3,2-a:2¡ä,3¡ä-c]phenazine (dppz in 6) were prepared, characterized and their DNA binding, photocleavage activity and photocytotoxicity studied. The complexes which showed a d-d band near 750 nm in DMF are efficient binders to calf thymus DNA (K_b: 3.2 ¡Á 10⁵-2.9 ¡Á 10⁶ M^?1). The complexes showed significant pUC19 DNA cleavage in near-IR light of 785 nm forming OH radicals and photocytotoxicity in HeLa cells in visible light with the benzo-[i]dipyrido[3,2-a:2¡ä,3¡ä-c]phenazine complex 5 showing a remarkably low IC₅₀ value of 0.036 ¦ÌM. Flow-cytometric analysis shows a high sub-G1 phase cell cycle arrest in HeLa cells by the complexes on photo-irradiation. The photocytotoxicity correlates well with the hydrophobicity, photosensitizing ability and DNA binding propensity of the complexes.