A ruthenium(II)-trithiacyclononane curcuminate complex: Synthesis, characterization, DNA-interaction, and cytotoxic activity

• Published in: Journal of coordination chemistry Vol. 70; no. 14; pp. 2393 - 2408
• Main Authors: Henriques, Magda Carvalho, Faustino, Maria Amparo F., Silva, Artur M. S., Felgueiras, Juliana, Fardilha, Margarida, Braga, Susana Santos
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 18-07-2017; Taylor & Francis Ltd
• Subjects: Coordination compounds; Curcumin; Cytotoxicity; Deoxyribonucleic acid; DNA; DNA-intercalation; Fluorescence; In vitro methods and tests; Infrared radiation; Melting; NMR; Nuclear magnetic resonance; Prostate; Ruthenium; ruthenium complexes; Ruthenium compounds; Salmon; spectroscopic characterization; Structural analysis; Viability
• ISSN: 0095-8972; 1029-0389
• DOI: 10.1080/00958972.2017.1336232

The coordination of ruthenium(II) complexes to anionic oxygen-based donors are very rare. This study describes a simple, one-pot method for obtaining [ruthenium(II)(trithiacyclononane)(curcumin)(S-DMSO)]Cl (1) in 37% yield. The structural characterization of complex 1 by elemental analysis, FT-IR, 1-D and 2-D NMR, ESI
+
-MS as well as UV-vis and fluorescence spectroscopies are presented. The DNA-melting temperature (T
m
) assay shows that salmon sperm DNA (smDNA) in the presence of complex 1 has a higher melting temperature, with ΔT
m
 = 7.4 °C, while in the presence of curcumin the melting temperature remains unaltered. The in vitro cytotoxic activities of curcumin and complex 1 were investigated using the tumor human prostate cell line, PC-3, and the healthy cell line, PNT-2. Complex 1 is innocuous toward normal prostate epithelial cells and, whereas curcumin is toxic, with inhibition rates of ca. 35 and 65% at 50 and 80 μM, respectively. On the tumor cell line PC-3, complex 1 did not cause viability changes, whereas curcumin exhibited dose-dependent inhibition, with ca. 73% inhibition at the highest concentration tested, i.e. 80 μM. This study suggests that coordination with the trithiacyclononane ruthenium(II) scaffold stabilizes the photochemical properties of curcumin and strongly changes its biologic activity.