Synthesis of Novel Schiff Base Metal Complexes of Aminophenols as Potential Antiseptic Agents
A Thesis Submitted to the School of Postgraduate Studies, University of Lagos
Advances in medicinal chemistry have been promoted by the role of organic compounds in regulating biological activities. Organic compounds such as benzimidazoles, benzothiazoles and Schiff bases have been reported to regulate biological activities (Jigna et al., 2005). One of the biological agents regulated by organic compounds include antibiotics. The discovery and development of antibacterial agents are among the most powerful and successful achievements of modern science and technology for the control of infectious diseases (Parekh et al., 2005). However, there have been increasing reports of resistance to existing antibacterial agents (Pablos-Mendez, 1998, Schrag et al., 2001). Resistance of microorganisms to existing antibacterial agents accounts for more than 85% of the mortality reported from infection worldwide (WHO, 2009). This has led to deaths from acute respiratory infections, diarrhoea, measles, AIDS, malaria and tuberculosis. Some of these infections are hospital acquired. Hospital-acquired infection (HAI) are infections not present and without evidence of incubation at the time of admission to a healthcare setting such as nosocomial. Hospital-onset infections have been associated with resistance of microorganisms to antiseptics and disinfectants (Coffin and Zaoutis, 2008). Common antiseptics and disinfectants used to counter HAI include chloroxylenols (Dettol, Morigad, Tiscol), chlorohexidines (Savlon, Purit), sodium hypochlorite (Jik) and hydrogen peroxide. Although chloroxylenol was launched for use in 1933, its use in hospitals has been discouraged due to reports that it is easily inactivated (Shanson, 1999), hence there is need for constant research into new compounds that are active against microorganisms and towards which resistance has not yet been developed. The effect of various brands of chloroxylenol disinfectants on some common hospital pathogens showed that chloroxylenol and chlorhexidines had less activity against gram negative organisms, inhibiting them only in the undiluted form (Ogunsola et al., 2000). Both developed and resource-poor countries are faced with the burden of healthcare-associated infections. A World Health Organization (WHO) study in 55 hospitals in 14 countries from four WHO regions showed that about 8.7% of hospitalized patients had nosocomial infections (Tikhomirov, 1987). The study on the efficacy of nosocomial infection control project (SENIC) from the 1970s showed nosocomial rates could be reduced by 32% if infection surveillance was coupled with appropriate infection control programs such as disinfection of hospital rooms (Hughes, 2008).