ABSTRACT
The ability of hesperidin [HP] to form complexes with five metals; cobalt, nickel, zinc, calcium and magnesium was investigated. The complexation was studied using U.V spectroscopic titration, in methanol as well as aqueous buffer solutions [physiological conditions]. Potential complexes were studied by IR and NMR spectroscopy, melting point and their solubility were also evaluated. The interaction of HP and its metal complexes with DNA was investigated by U.V spectroscopy. HP and its potential complexes were also tested for their ability to inhibit alpha amylase and alpha glucosidase enzymes. The results indicated that HP can form 1:1 complexes with cobalt, nickel and zinc in methanolic solution but not in aqueous buffers. Both HP and its metal complexes were found to intercalate DNA, at physiological condition, with preference to GC rich sequences. HP-metal complexes appeared to have higher affinity towards poly A DNA than the free HP. Neither HP nor its complexes exhibited antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa or Candida albicans. Results showed that HP has little inhibitory action on glucosidase and amylase enzymes with no obvious effect of complexation on the behavior of free HP. In conclusion HP was shown to form 1: complexes with the studied metal in methanol but not in aqueous buffer solutions. In presence of DNA however, complex formation in aqueous solutions seem to be encouraged with differential effect between the complexes and free HP
ABSTRACT
In this work the complexation of five NSAIDs with iron [Fe[3+]] was studied and the role of these iron complexes in reducing the proliferation of cancer cells was investigated. The stoichiometry and the formation constants of the complexes formed with different NSAIDs were calculated using the conductivity method. The metal-drug ratio for all drugs was 1:2 and their formation constant values were between 10[9] to 10[14]. The antiproliferative activity of the NSAIDs in their free and complex form was assessed using MCF-7 cells. After 72 hours incubation with the free drugs, mefenamic acid and diclofenac sodium showed the strongest antiproliferative effects with IC[50] of 70.54 +/- 15.29 microM and 108.38 +/- 11.28 microM, respectively. Indomethacin, naproxen and meloxicam had moderate to no effect at the concentrations tested. A linear correlation, with r= 0.876, between the formation constants of NSAlDs-Fe[3+] complexes and their cytotoxic effects was observed after 6 hours incubation. The ability of each drug to bind to DNA was examined together with the influence of ferric ions on the binding process. Drug-iron complexes were shown to bind to DNA, though with slightly different ratio. The results suggest that the complexes possess intrinsic cytotoxic effect
ABSTRACT
A simple spectroscopic method was developed for the quantitative determination of the macrolide antibacterials, clarithromycine [Clar] roxithromycin [Rox]. The method is based on the ability of both drugs to form ion associates [ion pair complex] with bromophenol blue which are extractable into dichloromethane. The ion pair complex exhibit maximum absorption at 414 nm with E 1 percent, 1cm of 228 and 234 for Clar and Rox respectively. A linear relationship [r> 0.9994] was established between the absorbance of the extract at 414 nm and the concentration of each drug. The method was linear in the concentration range 10-40 micro g/ml for both drugs. Percentage relative standard deviation of the absorbance values [n=10] at 10 micro g/ml was less than 0.7. The method was used to analyze the antibacterials Clar and Rox in tablets and raw material. Clar was also analyzed in suspension dosage from. Comparison of the method with standard HPLC method has shown that the method is accurate, precise and selective enough for determining the level of the antibacterials in a tablet or suspension preparation