A Rapid and Simple Spectrophotometric Determination of Traces of Chromium (VI) in Waste Water Samples and in Soil samples by using 2-Hydroxy, 3-Methoxy Benzaldehyde Thiosemicarbazone (HMBATSC)
A rapid and simple Spectrophotmetric method has been developed for the determination of microgram amount of Chromium (VI) in aqueous dimethyl formamide (DMF). Chromium (VI) forms a yellowish green coloured M:L complex with 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone in the acidic buffer medium (pH=6.0) at room temperature. The complex shows maximum absorption at 385nm. Beer's law is obeyed in the range 0.260 to 2.60 
Antileishmanial effect of mevastatin is due to interference with sterol metabolism
Visceral leishmaniasis (VL) is one of the most severe forms of leishmaniasis which is fatal if left untreated. Sterol biosynthetic pathway in Leishmania is currently being explored for its therapeutic potential. In the present study, we have evaluated the antileishmanial efficacy of mevastatin, a known inhibitor of 3-hydroxy-3-methyl glutaryl-CoA reductase (HMGR) enzyme. Mevastatin inhibited Leishmania donovani promastigotes and intracellular amastigotes with an 50 % inhibitory concentration (IC50) value of 23.8 ± 4.2 and 7.5 ± 1.1 μM, respectively, without exhibiting toxicity towards host cell line. Mevastatin also inhibited recombinant L. donovani HMGR (LdHMGR) enzyme activity with an IC50 value of 42.2 ± 3.0 μM. Kinetic analysis revealed that the inhibition of recombinant LdHMGR activity by mevastatin was competitive with HMG-CoA. Mevastatin-treated parasites exhibited 66 % reduction in ergosterol levels with respect to untreated parasites. Incubation of mevastatin-treated L. donovani promastigotes with ergosterol resulted in revival of cell growth, whereas cholesterol supplementation failed to cause reversal in cell death. To further prove the specificity of mevastatin for HMGR enzyme, HMGR-overexpressing parasites were used which showed almost threefold resistance to mevastatin. It also induced morphological changes in the parasite accompanied by lipid body accumulation. Hence, antileishmanial effect of mevastatin was due to the inhibition of HMGR, which eventually leads to reduction in ergosterol levels and hence parasite death. The present study may have implications in the treatment of visceral form of leishmaniasis.
Extraction-spectrophotometric determination of palladium(II) with 3,5-dichlorosalicylaldehyde-4-phenyl-3-thiosemicarbazone
A method for the extraction-spectrophotometric determination of palladium with 3,5-dichlorosalicylaldehyde-4-phenyl-3-thiosemicarbazone (CSAPS) is described. The method is based on the formation of an insoluble palladium(II)-CSAPS complex, which is extractable into chloroform from an aqueous solution at pH 0. The absorbance is measured at 410 nm and the molar absorptivity is 14300 l mol–1 cm–1. The complex system conforms to Beer's law for up to 8 p.p.m. of palladium(II). The method has been applied successfully to the determination of palladium in standard palladium carbon powder (palladium catalyst).