Synthesis, cytotoxicity, and antileishmanial activity of N,N'-disubstituted ethylenediamine and imidazolidine derivatives.

This paper describes the preparation of N,N'-disubstituted ethylenediamine and imidazolidine derivatives and their in vitro biological activities against Leishmania species. Of the nine synthesized compounds, five displayed a good activity in both L. amazonensis and L. major promastigotes. The compounds 1,2-Bis(p-methoxybenzyl) ethylenediamine (4) and 1,3-Bis(p-methoxybenzyl)imidazolidines (5) showed the best activity on intracellular amastigotes, with IC50 values of 2.0 and 9.4 microgram/mL, respectively. In addition, none of compounds were cytotoxic against mammalian cells. The leishmanicidal activity can be related with inhibition of polyamine synthesis and cellular penetration within biological membranes.

Synthesis of a new series of N,N'-dimethyltetrahydrosalen (H2[H2Me]salen) ligands by the reductive ring-opening of 3,3'-ethylene-bis(3,4-dihydro-6-substituted-2H-1,3-benzoxazines).

A new series of N,N'-bis(2'-hydroxy-5'-substituted-benzyl)-N,N -dimethylethane-1,2-diamines (N,N'-dimethyltetrahydrosalen) ligands were prepared in good yield by reduction of the respective 3,3'-ethylene-bis(3,4-dihydro-6-substituted-2H-1,3-benzoxazine) precursors with sodium borohydride . The ligands were characterized by IR, NMR, and elemental analysis, which showed the compounds to be consistent with the proposed structures. Ring-opening reactions of bis-1,3-benzoxazines in the presence of sodium borohydride to produce N,N'-dimethylated tetrahydrosalens (H(2) [H(2)Me]salen) have not been reported in the literature.

Encapsulation of Fe(III) and Cu(II) complexes in NaY zeolite.

The use of nonporphyrin complexes encapsulated in zeolites as catalysts for oxidation reactions has been improved in the past decades by the discovery of increasing numbers of nonheme monoxygenases. The zeolite lattice can change the oxidative chemistry of the metallocomplexes, resulting in a catalytic effect different from those observed in homogeneous reactions. We report the encapsulation of iron and copper metallocomplexes with the ligand (2-hydroxybenzyl)(2-methylpyridyl)amine, Hbpa, and iron complexes with the ligand N,N'-bis(2-hydroxybenzyl)-N,N'-bis(2-methylpyridyl) ethylenediamine, H(2)bbpen. The zeolite-encapsulated metallocomplexes were prepared by diffusion of the ligands through the pores of the zeolites, already exchanged with the respective metal. The syntheses were performed in methanol and toluene solutions. Elemental analysis of solids with the Hbpa ligand have indicated better complexation for synthesis in toluene, where 74% of the iron atoms were coordinated by the ligand, against 37% for the synthesis in methanol. For the immobilization with the H(2)bbpen ligand in toluene it was observed that 46% of the iron atoms are coordinated, showing that the diffusion of the small ligand Hbpa through the zeolite cage was facilitated. The EPR spectra of the solids show signals at g = 2.0, which was attributed to an Fe-Fe interaction from the noncoordinated atoms, and g = 4.3 attributed to iron (III) in a rhombic geometry.