Mahmood-ul-hassan, Z. Chohan, C. Supuran
2002
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0
Influential Citations
62
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Journal
Main Group Metal Chemistry
Abstract
A condensation reaction of 4-acetamidobenzaldehyde with 2-aminobenzothiazole, 2-amino-4methylbenzothiazole, 2-amino-4-methoxybenzothiazole, 2-amino-4-chlorobenzothiazole, 2-amino-6nitrobenzothiazole and 6-(methylsulfonyl)benzothiazole to form tridentate Schiff bases was used. These Schiff bases have been converted into their Zn(II) chelates. These Schiff bases and Zn(II) chelates of the type [M(L)2]C12 have been characterized by physical, spectral, and analytical data. The Schiff bases act tridentately and are proposed to have octahedral geometry. These compounds have also been screened for their antibacterial properties against pathogenic bacterial species i.e., Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. INTRODUCTION Benzothiazoles are well known biologically active compounds'". Much research has been focused" to highlight the ligational and biological behavior of Schiff bases and their derivatives. The azomethine linkage (CH=N), is significant feature that makes them interesting candidates" for biological activities as well as in the coordination chemistry. The biological activity of certain compounds is related to their ability to form complexes with the metal ions which may induce through coordination a "lock geometry" of the apoprotein metal binding site so that only certain substances are able to become attached to the framework formed by this interaction. Many of the anticancer drugs are versatile ligands, some of which exhibit increased 10 ?Π anticancer activity when administered in the form of their metal complexes ' . It has been suggested" despite some controversy that certain types of cancers are virus-caused. The interaction between the metal ion and the ligand with cancer-associated viruses might represent an important route in designing new anticancer therapies. The inverse process, i.e., coordinating a metal ion from an important biomolecule, for instance a zinc finger protein, has recently been used to design novel antiviral therapies, targeted against virus-causing infections 4 . All these observations and the essential role of azomethine linkage attracted our attention to synthesize some benzothiazole derived Schiff bases (HL'-HL ) (Fig 1) and their Zn(II) chelates (Table 2) and to study their biological behavior via their coordination with the expectation that this alteration may result in achieving new targets in synthesizing and designing of compounds that could fight agressively against antibiotic resistant strains. These synthesized compounds have been characterized by physical, spectral and analytical data and also screened for their antibacterial activities against pathogenic bacterial species i.e., Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. R=4-H (L) R=4-CH3 (L) R=4-OCH3(L) R=4-C1 (L) R=6-N02 (L) R=6-S02CH3 (L) Fig 1. Structure of Schiff bases EXPERIMENTAL Material and Methods All chemicals and solvents used were of Analar grade. All metal(II) salts were used as chlorides. IR spectra were recorded on a Philips Analytical PU 9800 FTIR spectrophotometer. UV-Visible spectra were obtained in DMF on a Hitachi U-2000 double-beam spectrophotometer. C, Η and Ν analyses was carried out by Butterworth Laboratories Ltd. Conductance of the metal complexes was determined in DMF on a Hitachi YSI-32 model conductometer. Magnetic measurements were made on solid complexes using the Gouy method. Melting points were recorded on a Gallenkamp apparatus and are uncorrected.