Bangladesh Pharmaceutical Journal 15(1): 83-87, 2012 Synthesis and Antimicrobial Studies of Copper (II) Metal Complexes that Specifically Recognize Nucleic Acid Bases A.K. M. Nur Alam Siddiki 1 , Md. Shahidur Rahman 1 , Mohammad Arifur Rahman 1 , Md. Abdus Salam 1 , Abdus Salam 1 , Md. Abu Yousuf 2 , Md. Farhadul Islam 3 and Md. Azharul Arafat 4 1 Department of Chemistry, University of Dhaka, Dhaka-1000, Bangladesh 2 Khulna University of Engineering and Technology, Khulna, Bangladesh 3 Rajshahi University, Department of Biochemistry and Molecular Biology, Bangladesh 4 Sylhet University of Science and Technology, Sylhet, Bangladesh Abstract Antimicrobial activities of metal complexes have been investigated due to their potential biological activity. S1 and S2 have been synthesized and their antibacterial and antifungal activities have been studied against some pathogenic bacterial and fungal strains by using disc diffusion method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were studied by serial dilution method against some gram positive and gram negative pathogenic bacteria. The compounds showed significant antimicrobial activities against all tested organisms, which are quite comparable to standard antibiotic kanamycin. The MIC values of the compounds were found to be in the range of 32~256 μg/mL. The low MIC and MBC values and high sensitivity of pathogenic microorganisms to the synthesized compounds led to conclude that the complexes of have potential antibiotic properties. Key words: Metal complex, Antibiotic, Antimicrobial agents, MIC and MBC. Introduction The discovery and development of antibiotics are among the most powerful and successful achievement of modern science and technology for the control of infectious diseases. However, the increasing microbial resistance to antibiotics in use now-a-days necessitates the search for new compounds with potential effects against pathogenic bacteria. Extensive investigations in the field of metal complexes and their Schiff bases have been reported. Their preparation, chemical and physical properties have been described by various workers. For developing potential antibiotic, metal complexes have been drawn attention of many investigators (Çukurovali et al., 2010; Carcelli et al., 1995; Anacona and Silva, 2005; Srinivasan, et al., 2005; Hossain, et al., 2008; Ajani, 2008; Nagar, 1990; Anacona and Patricia, 2010; Nagwa and Nassir, 2010) owing to their potential applications such as antibacterial, antifungal, antiviral, anti-inflammatory (Demertzi et al., 2009; Chohan et al., 2002; Hunoor et al., 2011), anti-tubercular (William and Ronald 1958; Qin-xi et al., 2000; Sandbhor et al., 2002), anti-HIV, herbicidal (Matsuzawa et al., 1987), etc. activities. Nickel (ìì) complexes of semicarbazone derivatives showed potent anticancer activity against MCF–7 cell lines (Afrasiabi et al., 2005). Two new alkylamine–substituted nickel (II)- salphen complexes have been prepared and their interactions with DNA were investigated and they showed that these complexes had a remarkable ability to stabilize G–quadruplex DNA and was inhibited telomerase activity (Julie et al., 2006). Mixed-Ligand Copper (II)–phenolate complexes showed potent anticancer activity against human cervical epidermoid carcinoma cell line (ME180) (Rajendiran et al., 2007). Antimicrobial and antifungal activities of various metal complexes have also been reported (Zahid et al., 2006). In this work, the synthesis and characterization of some metal complexes for pharmacological studies are reported. Materials and Methods Bacterial and fungal stains: The microorganisms used in the work were collected from the Microbiology Laboratory of the Institute of Nutrition and Food Sciences (INFS), Dhaka University. Chemicals and reagents: All the chemicals and reagents used throughout the investigation were of reagent grade. Correspondence to: Md. Abdus Salam; E-mail: abdussalam69@yahoo.com