Soil of arable land and meadows from the Ap horizon, taken from ten different localities, were investigated for different forms of Fe, including total (HF), pseudo-total (HNO 3 ), 0.1 M HCl extractable and DTPA (diethylenetriaminepentaacetic acid)-extractable. A sequential fractional procedure was employed to separate the Fe into fractions: water soluble and exchangeable Fe (I), Fe specifically adsorbed with carbonates (II), reducibly releasable Fe in oxides (III), Fe bonded with organic matter (IV) and Fe structurally bonded in silicates (residual fraction) (V). The soil pH, cation exchange capacity, and size fractions (clay and silt) had a strongest influence on the distribution of the different forms of Fe. The different extraction methods showed similar patterns of the Fe content in arable and meadow soils. However, the DTPA iron did not correspond with the total iron, which confirms the widespread incidence of irondeficiency in vertisols is independent of the total iron in soils. The amount of exchangeable (fraction I) and specifically adsorbed (II) iron showed no dependence on its content in the other fractions, indicating low mobility of iron in vertisols. The strong positive correlation (r = 0.812 and 0.956) between the content of iron in HNO 3 and HF and its contents in the primary and secondary minerals (fraction -V) indicate a low content of plant accessible iron in the vertisol. The sequential fractional procedure was confirmed as suitable for accessing the content and availability of iron in the vertisols of Serbia.

Square planar complexes of Ni(II) and Cu(II) with potassium 3-dithiocarboxy 3-aza-5-aminopentanoate have been prepared by direct synthesis. The obtained neutral complexes were characterized by elemental analysis, magnetic susceptibility measurements, infrared and electronic spectra. The thermal behaviour of both the Ni(II) and Cu(II) complexes, and the ligand itself was investigated by DSC and TG.

Complexes of zinc(II), cadmium(II), platinum(II) and palladium(II) with a new polydentate dithiocarbamate ligand, 3-dithiocarboxy-3-aza-5-aminopentanoate (daap-), of the type M(daap)2.nH2O (M= Zn(II), Cd(II), n = 2, or M= Pt(II) Pd(II), n = 0), have been prepared and characterized by elemental analysis IR and UV/VIS spectroscopy, as well as magnetic measurements. The spectra of the complexes suggest a bidentate coordination of the daap- ligand to the metal ions via the sulfur atoms of the deprotonated dithiocarbamato group. The fact that under the same experimental conditions its S-methyl ester does not form complexes could be taken as proof of the suggested coordination mode.

A novel (S,S)-R 2 eddip ester, O,O′-diisopentyl-(S,S)-ethylenediamine--N,N′-di-2-propanoate dihydrochloride (1) was synthesized and characterized by IR, 1 H-and 13 C-NMR spectroscopy, mass spectroscopy and elemental analysis. In vitro antitumor action of 1, and two more R 2 eddip esters, dialkyl (S,S)-ethylenediamine-N,N′-di-2-propanoate dihydrochlorides, obtained before (alkyl = n-Bu or n-Pe, 2 and 3, respectively), was determined against cervix adenocarcinoma (HeLa), human melanoma (Fem-x), human chronic myelogenous leukemia (K562) cells, and a non-cancerous cell line human embryonic lung fibroblast (MRC-5), using the microculture tetrazolium test MTT assay. Esters 1-3 showed higher cytotoxicity and better selectivity in comparison to cisplatin, used as reference compound. The highest activity was expressed by 1, with IC 50 (Fem-x) value of 1.51±0.09 µM.

Three octahedral chromium(III) complexes of the general formula Na[Cr(S,S-eddp)L].2H2O, where eddp = the tetradentate O-N-N-O-type ligand ethylenediamine-N,N?-di-S,S-2-propionate and L = a bidentate O-O-type ligand, either oxalate or malonate, were prepared. The complexes were synthesized by the reaction of chromium(III) chloride, S,S-eddp and malonic acid or sodium oxalate, at 60?C. The complexes were isolated chromatographically and the geometric configuration of the complexes was proposed on the basis of their infrared and electronic absorption spectra.