CHAPTER ONE
1.l INTRODUCTION
Antibiotics belong to a class of compounds of biosynthetic or semi-synthetic in nature. Most of them are produced by various species of microorganisms and other living synthetics and are capable in small concentrations of inhibiting the growth of or killing bacteria and other micro-organisms. An extensive review on the metal complexes of various antibiotics was published (1) It includes complexes of tetracycline and bleomycin, valinomycin, beauverian and otherenniatins, gramicidins, nactins, lasalcid, monensin, calcimycinand related antibiotics D-eycloserine and related aminoacids with antibiotics properties and iron-containing antibiotics.
Chlorotetracycline (aureomucin) and oxytetracycline (terramycin) were shown to have high affinity for the cations of heavy metals, the acidity of terracycline towards first row transition metals ions and the corresponding stability constants of the metal complexes have been reported. The stoichiometeries and concentrations of the different metal complexes formed by tetracyclines in vivo could be assessed on a quantitative basis by using high speed.(2) Thiadiazole derivates have been reported to be biologically versatile compounds, possessing antiviral, anti-bacterial, anti-pyretic, anti fungicidal, and analgesic activities. Complexes of 4-acetyl-2-(acetylamino)-5-dimethyl- 2-l, 3, 4-thiadiazole with cadmium, mercury and first-row transition metals have been described.