K. Kiran

Facile and sensitive spectrophotometric determination of vanadium in various samples

Novel reactions were developed for facile, sensitive and selective rapid spectrophotometric determination of trace amounts of vanadium(V) in various samples. The methods were based on the interactions of 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) with N-(1-naphthyl)ethylenediamine dihydrochloride (NEDA) in the presence of vanadium to give blue colored derivative or on oxidation of dopamine hydrochloride (DPH) by vanadium in acidic medium and coupling with MBTH to yield pink color derivative. The blue color derivative having an absorbance maximum at 595nm was stable for 9 days and the pink color derivative with λ(max) 526nm for 5 days. Beers law is obeyed for vanadium in the concentration range 0.05-6.0μgml(-1) (blue color derivative) and 0.06-7.0μgml(-1) (pink color derivative), respectively. The optimum reaction conditions and other important analytical parameters were established. Interference due to various non-target ions was also investigated. The proposed methods were applied to the analysis of vanadium(V) in environmental, biological, pharmaceutical and steel samples. The performance of proposed method was evaluated in terms of Students t-test and variance ratio F-test that indicates the significance of proposed method over reported method.

Synthesis and biological evaluation of boswellic acid-NSAID hybrid molecules as anti-inflammatory and anti-arthritic agents

Methyl esters of the β-boswellic acid (BA) and 11-keto-β-boswellic acid (KBA) obtained from Boswellia serrata resin were subjected to Steglich esterification with the different non-steroidal anti-inflammatory drugs (NSAID) viz., ibuprofen, naproxen, diclophenac and indomethacin. The novel hybrids of methyl boswellate (5-8) and that of methyl 11-keto boswellate (9-12) were evaluated for anti-inflammatory activity by carrageenan-induced rat hind paw edema model and anti-arthritic activity by Complete Freunds Adjuvant (CFA) induced arthritis in Wister albino rat. Significant inhibition on carrageenan-induced paw edema has been observed with 5, 6 and 10 where as in CFA induced rats, hybrids 5, 8, 9 and 12 exhibited pronounced antiarthritic activity. Hybrid molecules 5 and 9 have been found to be more effective in inhibiting in-vivo COX-2 than ibuprofen by itself, thus showing the synergistic effect. Hybrid 5 and 9 tested for in-vitro lipoxygenase and cyclooxygenase-2 (LOX/COX-2) inhibitory activity. The studies revealed that both 5 and 9 inhibited COX-2 relatively better than LOX enzyme.

Novel solid-phase extraction and preconcentration technique coupled with ICP-AES for the determination of Cr(III), Ni(II), and Zn(II) in various water samples

Newly synthesized 2-propylpiperidine-1-carbodithioate (2-PPC) was used for the extraction of Cr(III), Ni(II), and Zn(II) from various water samples. In the present investigation, the use of a syringe loaded with sorbent for the separation and enrichment of Cr(III), Ni(II), and Zn(II) prior to their determination by inductively coupled plasma-atomic emission spectrometry (ICP-AES) was proposed to substitute the batch and column techniques. The described method was compared with the column technique with respect to fastness, simplicity, recovery, and risk of contamination. The syringe was loaded with 1.0 g of sorbent in order to retain the analyte elements. Next, 7.0 mL of sample solution (pH 5.0 ± 0.2) was drawn into the syringe in 15 s and discharged over 15 s. Then, an eluent (3.0 M HCl) was drawn into the syringe and ejected back to desorb the analyte elements. At the optimum conditions, the percentage recoveries of Cr(III), Ni(II), and Zn(II) were in the range of 94.50 to 99.62% with a standard deviation (S.D.) of 0.03%. The elements could be concentrated by drawing and discharging several portions of sample successively and eluting only one time. The detailed study of various interferences proved the method to be highly selective. The risk of contamination is less than that with the column technique. The method was successfully applied to the determination of Cr(III), Ni(II), and Zn(II) in spiked and natural water samples. The results obtained are in good agreement with those obtained by the reported methods at the 95% confidence level.

RETRACTED: Development of novel reactions for the simple and sensitive spectrophotometric determination of vanadium in various samples

This article has been retracted at the request of the Editors-in-Chief. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). Reason: Considerable concern was raised about the research purportedly conducted at Sri Venkateswara University, India with the alleged involvement of Professor P. Chiranjeevi. Questions were raised as to the volume of publications, the actual capacity (equipment, orientation and chemicals) of the laboratory in which Professor Chiranjeevi worked, the validity of certain of the research data identified in the articles, the fact that a number of papers appear to have been plagiarized from other previously published papers, and some aspects of authorship. Professor Chiranjeevi was given the opportunity to respond to these allegations. Thereafter, a committee was constituted by the University to look into these allegations. Based on the enquiry committee report, we have been informed by the head of the Department of Chemistry at Sri Venkateswara University that the university authorities have taken disciplinary action against ProfessorChiranjeevi, as the university considers that there are grounds for such action. Therefore, based on the results of this investigation, the Editors-in-Chief are retracting this article.