Structural, Spectral, Biological and Electrochemical Studies Of Some ...

Recently radionuclides have attracted considerable attention In nuclear
medicine because they include isotopes with both diagnostic and therapeutic potential
[9]. They are becoming increasingly available to the medicinal community using
generator systems and improvements in small cyclotron production. It is reported
that Ga(lll) complexes of 2-acetylpyridine thiosemicarbazones gained more attention
because they offer a convenient source of y-ray emitters for position emission
tomography imaging in institutions that do not have a site cyclotron [10]. Recently
Kepper et al developed gallium complexes which showed profound antiviral and
antitumor activity with energy, which make them useful for medical diagnostic agent
[11]. There appeared some reports on the synthesis and single crystal studies of
thiosemicarbazones ofaluminum.
Thiosemicarbazones exhibit significant antimycobacterial activity against
both tubercle and leprosy bacilli in vivo. The antibacterial activity of
thiosemicarbazones against mycobacterium tuberculosis in vitro was first reported by
Domagk et.al and later confirmed in vivo. The most important one is thiacetazone (p­
acetamido benzaldehyde) thiosemicarbazones. The drawbacks such as toxic effects
including hemolytic anemia, edema, excessive skin eruptions and hepatic
dysfunctions and development of resistance to the drugs are overcome by coupling
thiacetazone with other antitubercular drugs, especially isoniazide. Dobek et al
reported [12] the synthesis of certain thiosemicarbazones derived from
2-acetylpyridine, having substantial clinical significance for human beings.
Recently it is reported that thiosemicarbazones of 2-acetylpyridine possess
antileprotic activity and ribonucleotide diphosphate reductase (RDR) activity. This
series of compounds correlates well with the observed antileprotic properties in
mycobacterial systems suitable for in vitro testing [13]. The strong metal chelating
ability of tridentate thiosemicarbazones is thought to be responsible for their
biological activity and any alteration that hinders this chelation leads to loss of
activity. Recently there appeared a report on the biological effects of
thiosemicarbazones on Friend erytholeukemia cells by an in vitro test [14].
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