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

g)/mL. Since then, several workers have reported the antimicrobial activity of
thiosemicarbazones against selected plant pathogenic and saprophytic fungi [30].
The antiviral effect ofthiosemicarbazones was first demonstrated by Hamre et al who
showed that p-aminobenzaldehyde -3-thisemicarbazone and several of its derivatives
were active against vaccinia virus in mice [31]. These studies were extended to
include thiosemicarbazones of isatin, benzene, thiophene, pyridine and quinoline
derivatives, which also showed activity against vaccinia - induced encephalitis.
Later Bauer and eo-workers isolated isatin-3-thiosemicarbazone having greatest
activity against vaccinia virus. Thiosemicarbazones have also been tested against a
variety of other viral infections including herpes virus, adenovirus, poliovirus,
rhinovirus and RNA tumor virus with mixed results [32]. An extensive series of
thiosemicarbazones obtained from 2-acetylpyridine was tested by Klayman et al for
antimalarial activity against plasmodium berghi in mice. Recently, it has been shown
that 2-fonnylpyridine thiosemicarbazones inhibited adenosine uptake in rodent
erythrocytes and reticulocytes parasitized with plasmodium berghi. The
thiosemicarbazone derived from 2-fonnylpyridine showed mild antileukemic activity
against 1-1210 tumor in mice [33]. These observations have provided an impetus to
the synthesis of large number of transition metal complexes of heterocyclic
thiosemicarbazones.
1.4Objective and scope of the present work
Transition metal complexes with thiosemicarbazones exhibit a wide range of
stereochemistries and possess potential biological activity. Metal complexes of
thiosemicarbazones are proved to have improved pharmacological and therapeutic
effects because ofthe following factors.
• Considerable reduction ofdrug resistance on complexation.
• Form complexes with biologically essential elements.
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