Bromlanmış 8-Hidroksi Kinolinlerin ve Palladyum Komplekslerinin Antikanser Özelliklerinin İncelenmesi: Yapı-Aktivite İlişkisi (SAR)

Amaç: Bu çalışmada, 7-bromo-8-hidroksikinolin (2) ve 5,7-dibrom-8-hidroksikinolin (3) bileşiklerinin Palladyum (Pd) kompleksleri sentezlendi. Oluşan kompleks bileşikler (4 ve 5) ile başlangıç bileşiklerinin (2 ve 3) antikanser potansiyelleri ve sitotoksisiteleri karşılaştırmalı olarak incelendi. Yöntem: 8-Hidroksikinolin (8-OHQ, 1), moleküler brom (Br2) ile  muamele edildi. Reaksiyon sonucu, 7-bromo-8-hidroksikinolin (7-Br-8-OHQ, 2) ve 5,7-dibromo-8-hidroksikinolin (5,7-diBr-8-OHQ, 3) elde edildi. Bu moleküller, kompleksleşme reaksiyonları ile Palladyum koordinasyon bileşiklerine (4 ve 5) dönüştürüldü. Sentezlenen bileşik ve komplekslerin (2 -5) antikanser potansiyel ve özellikleri incelendi. Bu amaçla HeLa, HT29 ve C6 hücre hatlarına karşı SRB hücre proliferasyonu ile LDH sitotoksisite testleri uygulandı. Bulgular: 7-Br-8-OHQ 2 ve 5,7-dibromo-8-OHQ 3 bileşikleri test edilen hücre hatlarının hücre proliferasyonunu inhibe etmiştir.  Fakat bu bileşiklerin Palladyum (Pd) kompleksleri (4 ve 5) durumunda antiproliferatif etki önemli derecede azalmıştır. 7-Br-8-OHQ 2 ve 5,7-diBr-8-OHQ 3  bileşikleri HeLa hücre hatlarında düşük sitotoksik etki göstermesine rağmen, bu bileşiklerin (2 ve 3) C6 hücre hatlarında oldukça sitotoksik olduğu belirlenmiştir. Sonuç: Kinolin halkasında  C-8 konumunda –OH (hidroksi) fonksiyonel grubu yanında brom gruplarının bağlı olması   yüksek antiproliferatif etkiden sorumlu olduğu düşünülmektedir. Kompleksleşme ile kinolin yapısındaki hidroksi ve amin grupları bloke edilmektedir. Bu yüzden kompleks bileşikler (4 ve 5) durumunda  antikanser aktivite oldukça azalmaktadır.   

The Studies of Anti-Cancer Activity of Brominated 8-Hydroxy Quinolines and Their Palladium Complexes: Structure-Activity Relationship (SAR)

Aim: In this study, Pd coordination complexes of 7-bromo-8-hydroxyquinoline (7-Br-8-OHQ, 2) and 5,7-dibromo-8-hydroxyquinoline (5,7-diBr-8-OHQ,3) were prepared. The anticancer and cytotoxic potentials of Palladium complexes (4 and 5) obtained from bromo hydroxides 2 and 3 were studied comparatively. Method: 7-bromo-8-hydroxyquinoline (7-Br-8OHQ, 2) and 5,7-dibromo-8-hydroxyquinoline (5,7-diBr-8-OHQ,3) were generated when 8-hydroxyquinoline (1) was treated with molecular bromine (Br2). These compounds were converted to corresponding Pd coordination compounds 4 and 5 via complexation reactions. Antiproliferative and Cytotoxic potentials of the compounds 2-5 against HeLa, HT29 and C6 cell lines were tested by using SRB cell proliferation and LDH cytotoxcity assays.  Findings: 7-Br-8-OHQ 2 and 5,7-diBr-8-OHQ 3  inhibited the proliferation of all cell lines tested. The antiproliferative potential of Pd complexes (4 and 5) of the molecules (2 and 3) was significantly higher. The cytotoxic activities of 7-Br-8-OHQ 2 and 5,7-diBr-8-OHQ 3 were different on HeLa and C6 cells, indicating cell selective activity.  Conclusion: We concluded that the OH functional group at C-8 position and the bromo groups at C5 and/or C7 positions of quinoline skeleton may be responsible for high antiproliferative potential. On the other hand, low anticancer activity of the coordination compounds (4 and 5) may be attributed to blocking hydroxy and amine groups of quinoline core by complexation.  

___

  • 1. Prachayasittikul V, Prachayasittikul S, Ruchirawat S, Prachayasittikul V. 8-Hydroxyquinolines: a review of their metal chelating properties and medicinal applications. Drug Des. Dev. Ther. 2013;7:1157–1178.
  • 2. Chan-On W, Huyen N, Songtawee N, Suwanjang W, Prachayasittikul S, Prachayasittikul V. Quinoline-based clioquinol and nitroxoline exhibit anticancer activity inducing Fox M1 inhibition in cholangiocarcinoma cells. Drug Des. Dev. Ther. 2015;9:2033–2047.
  • 3. Naber KG, Niggemann H, Stein G. Review of the literature and individual patients’ data meta-analysis on efficacy and tolerance of nitroxoline in the treatment of uncomplicated urinary tract infections. BMC Infect. Dis. 2014;14:628.
  • 4. Lazovic J, Guo L, Nakashima J, Mirsadraei L, Yong W, Kim HJ. Nitroxoline induces apoptosis and slows glioma growth in vivo. Neuro-Oncol. 2015;17(1):53–62.
  • 5. Jampilek J, Dolezal M, Kunes J, Buchta V, Kralova K. Investigating the Antiproliferative Activity of Quinoline-5,8-Diones and Styrylquinolinecarboxylic Acids on Tumor Cell Lines. Med. Chem. 2005;1:591.
  • 6. Li L, Xu B. Synthesis and characterization of 5-substituted 8-hydroxyquinoline derivatives and their metal complexes. Tetrahedron. 2008;64:10986-10995.
  • 7. Khan H, Badshah A, Murtaz G, Said M, Rehman Z, Neuhausen C, Todorova M, Jean-Claude BJ, Butler IS. Synthesis, characterization and anticancer studies of mixed ligand dithiocarbamate palladium(II) complexes. Eur. J. Med. Chem. 2011;46:4071-4077.
  • 8. Navarro M, Peña NP, Colmenares I, Gonzáles T, Arsenak M, Taylor P. Synthesis and characterization of new palladium–clotrimazole and palladium–chloroquine complexes showing cytotoxicity for tumor cell lines in vitro. J. Inorg. Biochem. 2006; 100:152-157.
  • 9. Jiang H, Taggart JE, Zhang X, Benbrook DM, Lind SE, Ding WQ. Nitroxoline (8-hydroxy-5-nitroquinoline) is more a potent anti-cancer agent than clioquinol (5-chloro-7-iodo-8-quinoline). Cancer Lett. 2011; 312:11-17.
  • 10. Sahin A, Cakmak O, Demirtas I, Okten S, Tutar A. Efficent and Selective Synthesis of Quinoline Derivatives. Tetrahedron. 2008;64:10068-10074.
  • 11. Ökten S, Eyigün D, Çakmak O. Synthesis of Brominated Quinolines, Sigma J. Eng. Nat. Sci. 2015;33:8-15.
  • 12. Ökten S, Çakmak O. Synthesis of Novel Cyano Quinoline Derivatives. Tetrahedron Lett. 2015;56(39):5337–5340. 13. Şahin ÖY, Ökten S, Tekin Ş, Çakmak O. Determination of anticancer activities of some quinoline derivatives against C6 tumor cells. J Biotech. 2012;161:S24.
  • 14. Ökten S, Şahin ÖY, Tekin Ş, Çakmak O. In vitro antiproliferative/cytotoxic activity of novel quinoline compound SO-18 against various cancer cell lines. J Biotech. 2014;185:S106.
  • 15. Köprülü TK, Tekin Ş, Ökten S, Çınar M, Duman S, Çakmak O. Detection of mechanism and anticancer activity of the new quinoline compounds MC20 and MC21. J Biotech. 2014;185:S93.
  • 16. Ökten S, Çakmak O, Tekin Ş, Köprülü TK. A SAR Study: Evaluation of bromo derivatives of 8-substituted quinolines as novel anticancer agents, Letters in Drug Design and Discovery. 2017: revizyon hali kabul edildi.
  • 17. Ökten S, Çakmak O, Saddiqa A, Keskin B, Özdemir S, İnal M. Reinvestigation of bromination of 8-substituted quinolines and synthesis of novel phthalonitriles. Org. Comm. 2016; 9(4):82-93.
  • 18. Skehan P, Storeng R, Scudiero D, Monks A, McMahon J, Vistica D, Warren JT, Bokesch H, Kenney S, Boyd MR. New colorimetric cytotoxicity assay for anticancer-drug screening. J. Natl. Cancer Inst. 1990;82:1107–1112.
  • 19. Papazisis KT, Geromichalos GD, Dimitriadis KA, Kortsaris AH. Optimization of the sulforhodamine B colorimetric assay. J. Immunol. Methods. 1997;208:151–158.