A rice fungicide blasticidin S efficiently binds Cu(II) ions and prevents DNA from metal-induced damage

• Published in: Journal of inorganic biochemistry 2013-10, Vol.127, p.73-78
• Main Authors: Stokowa-Sołtys, Kamila, Jeżowska-Bojczuk, Małgorzata
• Format: Article
• Language: English
• Subjects: Antioxidant; Blasticidin S; Coordination Complexes - chemistry; Coordination Complexes - pharmacology; Copper - chemistry; Copper - metabolism; Copper(II) coordination; DNA - chemistry; DNA copper-induced degradation; DNA Damage - drug effects; Electron Spin Resonance Spectroscopy; Fungicide; Humans; Ions; Models, Molecular; Nucleosides - chemistry; Nucleosides - metabolism; Nucleosides - pharmacology; Oryza; Oryza sativa
• ISSN: 0162-0134; 1873-3344
• DOI: 10.1016/j.jinorgbio.2013.06.014

Blasticidin S is a representative of the aminoacylnucleoside class of antibiotics and it possesses fungicidal properties against the virulent fungus which causes a serious rice blast disease in Asia. It is widely used to control rice blast by foliar application as a crop protection agent. Serious copper contamination is observed in some areas of China. Moreover, some paddy soils present a potential risk of copper accumulation in the human body through the food chain, leading to several disorders. This work presents the results of combined potentiometric and spectroscopic (UV–visible, EPR, CD, NMR) data which lead to the conclusion that the antibiotic is capable of binding copper, and the resulting complexes are likely to form in the soil. The process of complex formation has a potential influence on the population feeding on a rice-based diet. Moreover, the results of electrophoretic experiments revealed that complexes do not cleave DNA. On the contrary, the presence of blasticidin S may prevent DNA from a Cu(II)-induced damage. Copper(II) complex of blasticidin S was studied regarding its coordination pattern as well as the impact on the plasmid DNA. Surprisingly, DNA damage is not observed. This result indicates that BS can be considered as a ligand that effectively lowers the oxidative activity of Cu(II) ion. [Display omitted] •Acid-base characteristic of the blasticidin S•Increased copper level in the soil facilitate formation of complexes•Stability constants and structures of Cu(II)-blasticidin S complexes•Blasticidin S diminish the oxidative properties of Cu(II) ion