Antifungal and antitumor activity of heterocyclic thiosemicarbazones and their metal complexes: current status

Abstract

More than 75 substituted thiosemicarbazones and a number of metal complexes of each have been assayed for their antifungal activity. Their activity is significantly affected by the substituted groups attached at both 1N and 4N of the thiosemicarbazone moiety. Greatest activity occurs for 2-substituted pyridine thiosemicarbazones with differences observed for 2-formylpyridine, 2-acetylpyridine and 2-benzoylpyridine derivatives and their metal complexes. Further, there are activity differences for 4N-alkyl-, 4N-aryl-, 4N-dialkyl- and 3-azacyclothiosemicarbazones and their metal complexes as well as changes in the substituent size among each of these subgroups. Cu(II) complexes are often more active than the uncomplexed thiosemicarbazones, with the latter showing similar activity to Ni(II) complexes in many instances. The reduction potential of the thiosemicarbazone ligand in a Cu(II) complex, the strength of the ligand field and various spectral properties can be correlated to the inhibitory activity.

Synthesis and biological activity of acetylacetone thiosemicarbazone and their metallic complexes

“…Thiosemicarbazones are of considerable interest because of their chemistry and potentially beneficial biological activity, such as antibacterial, antifungal, antiviral, antiamoebic, antimalarial and antitumor activity (Klayman et al, 1979;Scovill et al, 1984;Klayman et al, 1984;Liberta et al, 1992;West et at., 1993;Liu et al, 1995;Sharma et al, 2005;Rebolleo et al, 2005). The biological activities of thiosemicarbazones are considered to be due to their ability to form chelates with metals.…”

Synthesis, spectral characterization and biological activity studies of transition metal complexes of Schiff base ligand containing indole moiety

“…The analysis of the spectrum gives g 2.25 and g ⊥ 2.06 (Table 4). The trend g > g ⊥ > 2.0023 observed for the complex under study indicates that the unpaired electron is localized in the d 2 x − y 2 orbital of the Cu(II) ion. The observed geometric parameter calculated by the …”

2-Acetylpyridinium 4N-Phenylthiosemicarbazone Chloride 1.25-Hydrate

“…Thiosemicarbazones (TSCs) have aroused considerable interest in chemistry and biology owing to their antibacterial, antimalarial, antineoplastic and antiviral activities (Liberta & West, 1992, and references therein). TSCs represent some of the most potent inhibitors of ribonucleoside diphosphate reductase known.…”

“…TSCs represent some of the most potent inhibitors of ribonucleoside diphosphate reductase known. The reductive conversion of ribonucleotides to their deoxyribonucleotide counterparts is a particularly critical step in the synthesis of DNA since deoxyribonucleotides are present at extremely low levels in mammalian cells and it has been argued that an inhibitor of ribonucleotide reductase could be more effective than an inhibitor of DNA polymerase in blocking DNA synthesis (Corey & Chiba, 1989;Liberta & West, 1992, and references therein).…”