2-Acetylpyridine thiosemicarbazones. 1. A new class of potential antimalarial agents

Abstract

Based on the antimalarial properties observed for 2-acetylpyridine 4-phenyl-3-thiosemicarbazone (1), an extensive series of related thiosemicarbazones was prepared and tested against Plasmodium berghei in mice. Screening results indicated that the presence of the 2-pyridylethylidene group was critical and that certain phenyl, benzyl, phenethyl, or cycloalkyl groups at N4 of the thiosemicarbazone moiety also contribute to antimalarial activity.

Design, synthesis and biological evaluation of thiosemicarbazones, hydrazinobenzothiazoles and arylhydrazones as anticancer agents with a potential to overcome multidrug resistance

“…Literature data suggest that the imino carbon of thiosemicarbazones [68], aroylhydrazones [51], arylhydrazones [13] and benzothiazoles [49,50] may be a sensitive position for finetuning the biological activity of these Schiff bases. The role of imino carbon methylation on the toxicity of the investigated compounds is also evident from the structure-activity matrix shown in Figure 4.…”

“…Here assay dependent artefacts were excluded by using two complementary viability assays ( Figure S2). In many cases not only free ligands, but also their metal complexes possess biological activity: picolinylidene TSC derivatives or their metal complexes have been reported to possess antimalarial [68], modest antibacterial [86], modest (to no) antifungal [87,88], but promising antitumor activity [88][89][90]. Salicylidene TSCs form redox-active complexes with various metal ions, including Ru(II) [91,92] and Cu(II) [93][94][95].…”

Synthesis, Spectral and Biocidal Studies of Co(II), Ni(II) and Cu(II) Complexes of Hydrazone

“…The proposed geometry is further supported 27,28 by high µ eff value in the range 4.84-4.97B.M. The Ni(II) complexes display three electronic bands in the regions, 13000, 17400 and 23000; assignable to transitions, 3 A 2g (F) → 3 T 2g (F), Ni(II) complexes is also supported by m eff value in the range 3.11-3.17 BM respectively. The electronic spectra of all the Cu(II) complexes exhibit two spectral bands in the regions 12000cm -1 and 18000 cm -1 indicating octahedral 26,30 geometry for Cu(II) complexes.…”

2-Acetylpyridinium 4N-Phenylthiosemicarbazone Chloride 1.25-Hydrate

“…This planar arrangement leads to enhanced possibilities for resonance. This is confirmed by a shortening of the N4--C7 bond to 1.330o(3),~, an elongation of the N3--C7 bond to 1.376 (3)A, a shortening of the N2mN3 bond to 1.363 (4)~,, an elongation of the N2--C6 bond to 1.284 (3)A and a shortening of the C6--C5 bond to 1.474 (4) 2-Acetylpyridine 4N-phenylthiosemicarbazone (HAc4NPh) N4 was prepared by reacting equimolar amounts of thio-Cl semicarbazide dissolved in ethanol and 2-acetylpyridine (Klay-c2 man, Bartosevich, Griffin, Mason & Scovill, 1979 Intensities were corrected for Lorentz and polarization effects.…”