Synthesis, characterization and antidiabetic properties of N(1)-2,4-dihydroxybenzylidene-N(4)-2-hydroxybenzylidene-S-methyl-thiosemicarbazidato-oxovanadium(IV)

A new oxovanadium(IV) chelate [VOL] (L: N(1)-2,4-dihydroxybenzylidene-N(4)-2-hydroxybenzylidene-S-methyl-thiosemicarbazidato) was synthesized and characterized by elemental analysis, conductivity and magnetic measurements, UV-vis, IR, EPR spectroscopy and mass spectrometry. The biochemical and immunohistochemical effects of the administration of the vanadium complex (VOL) into the pancreas of normal and streptozotocin-induced diabetic rats were profoundly investigated. The animals were randomly divided into four groups. Group I: control (intact) animals. Group II: control animals administered with VOL. Group III: STZ-induced diabetic animals. Group IV: STZ-induced diabetic animals administered with VOL. VOL was given to some of the experimental animals by gavage at a dose of 0.2mM/kg every day for 12 days. Blood samples were collected from animals, on 0 and 1, 6 and 12 days after STZ injection. On day 12, the pancreatic tissues were taken from the animals. The tissue sections were labelled with streptavidin biotin peroxidase technique for insulin. In the diabetic group, the blood glucose levels, aspartate and alanine transaminases, alkaline phosphatase activities were increased. But, in the diabetic+VOL groups, the blood glucose levels, aspartate and alanine transaminases, alkaline phosphatase activities were reduced. In the diabetic group, a decrease in the pancreatic glutathione levels, glutathione peroxidase and superoxide dismutase activities and an increase in the pancreatic lipid peroxidation level and catalase activities were observed. The administration of VOL to the diabetic rats reversed this diabetic effect due to its insulinomimetic effects. According to the immunohistochemical and biochemical results obtained, it was concluded that VOL can regenerate B cells of the pancreas in experimental diabetes and has an antidiabetic and protective effects on the pancreas.     

Cytotoxic activities of new iron(III) and nickel(II) chelates of some <Emphasis Type="Italic">S</Emphasis>-methyl-thiosemicarbazones on K562 and ECV304 cells

The S-methyl-thiosemicarbazones of the 2-hydroxy-R-benzaldehyde (R= H, 3-OH 3-OCH₃ or 4-OCH₃) reacted with the corresponding aldehydes in the presence of FeCl₃ and NiCl₂. New ONNO chelates of iron(III) and nickel(II) with hydroxy- or methoxy-substitued N ¹,N ⁴-diarylidene-S-methyl-thiosemicarbazones were characterized by means of elemental analysis, conductivity and magnetic measurements, UV-Vis, IR and ¹H-NMR spectroscopies. Cytotoxic activities of the compounds were determined using K562 chronic myeloid leukemia and ECV304 human endothelial cell lines by MTT assay. It was determined that monochloro N ¹-4-methoxysalicylidene-N ⁴-4-methoxysalicylidene-S-methyl-thiosemicarbazidato-iron(III) complex showed selective anti-leukemic effects in K562 cells while has no effect in ECV304 cells in the 0.53 μg/ml (IC₅₀) concentrations. Also, some methoxy-substitued nickel(II) chelates exhibit high cytotoxic activitiy against both of these cell lines in low concentrations. Cytotoxicity data were evaluated depending on cell lines origin and position of the substituents on aromatic rings.     

Synthesis, characterisation and cytotoxic properties of the N1,N4-diarylidene-S-methyl-thiosemicarbazone chelates with Fe(III) and Ni(II)

Reactions of 2-hydroxy-3-methoxy, 2-hydroxy-4-methoxy-benzaldehyde with 3- and 4-methoxy-substituted salicylaldehyde S-methyl-thiosemicarbazones in the presence of FeCl(3) and NiCl(2) resulted in the corresponding methoxy-substituted N(1),N(4)-diarylidene-S-methyl-thiosemicarbazone chelates. Characterisation of the compounds in the [Fe(L)Cl] and [Ni(L)] general formula was accomplished by means of elemental analysis, conductivity and magnetic measurements, (1)H NMR, UV-vis, IR and mass spectroscopy. Cytotoxicity and proliferation experiments using K562 chronic myeloid leukemia cell line and ECV 304 human endothelial cell line imply that the iron(III) chelates may have anti-leukemic effects with 3.5 microg/dl LD(50) dose.