Some nontoxic metal-based drugs for selected prevalent tropical pathogenic diseases.

Metal coordination of bioorganic compounds from both natural and synthetic products is not only gaining recognition in drug design and medicinal inorganic chemistry research, also they are being considered in the improvement of the bioactivity of drugs. What is done in this paper is a review of recent advances in the study of coordination-driven drug delivery, i.e., metal-based drugs (MBDs). The role of some late first row transition metal ions namely Fe, Cu and Zn in the biological activities of metallodrugs such as antimalarials and antimicrobials are highlighted. It was revealed that the interaction between these bio-essential transition metal ions and the organic drugs could enhance the diagnostic and therapeutic potentials of such formed drugs. This is because such interactions were proved to have improved the stability, bioavailability and cell delivery functions of the metallodrugs. Emphasizing on the challenge of metal ions toxicity, the researchers concluded on the need for the development of MBDs to combat drug resistant parasites without causing injury to normal cells. This would be of significance in addressing the concern World Health Organisation of ameliorating the increasing mortality rate in developing countries.

Poly[beta-(1-->4)-2-amino-2-deoxy-D-glucopyranose] based zero valent nickel nanocomposite for efficient reduction of nitrate in water.

Chemical reduction of nitrate using metal nanoparticles has received increasing interest due to over-dependence on groundwater and consequence health hazard of the nitrate ion. One major drawback of this technique is the agglomeration of nanoparticles leading to the formation of large flocs. A low cost biopolymeric material, poly [beta-(1-->4)-2-amino-2-deoxy-D-glucopyranose] (beta-PADG) obtained from deacetylated chitin was used as stabilizer to synthesize zero valent nickel (ZVNi) nanoparticles. The beta-PADG-ZVNi nanocomposite was characterized using infra red (IR), UV-Vis spectrophotometric techniques and Scanning Electron Microscope (SEM). The morphology of the composite showed that beta-PADG stabilized-ZVNi nanoparticles were present as discrete particles. The mean particle size was estimated to be (7.76 +/- 2.98) nm and surface area of 87.10 m2/g. The stabilized-ZVNi nanoparticles exhibited markedly greater reactivity for reduction of nitrate in water with 100% conversion within-2 hr contact owing to less agglomeration. Varying the beta-PADG-to-ZVNi ratio and the ZVNi-to-nitrate molar ratio generally led to a faster nitrate reduction. About 3.4-fold difference in the specific reaction rate constant suggests that the application of the beta-PADG-stabilizer not only increased the specific surface area of the resultant nanoparticles, but also greatly enhanced the surface reactivity of the nanoparticles per unit area.