Definitive identification of cysteine and glutathione complexes of bismuth by mass spectrometry: assessing the biochemical fate of bismuth pharmaceutical agents

Solutions containing BiCl3, bismuth subsalicylate or Bi(NO3)3 with L-cysteine, DL-homocysteine, D-methionine or glutathione have been examined by electrospray mass spectrometry. Prominent peaks are assigned to bismuth complexes of these biomolecules and provide insight towards understanding the bioactivity of bismuth compounds.     

Formation of nitrogen‐containing heterocycles using di(imidazole‐1‐yl)methanimine

A mild and efficient synthesis of five‐ and six‐membered nitrogen containing heterocyclic compounds, in which di(imidazole‐1‐yl)methanimine serves as a one‐carbon source, is reported.     

Visible light induced photocatalytic reaction of rhodamine B dye via 12-tungstosilicic acid in water

Using 12-tungstosilicic acid (SiW124-) as the catalyst, rhodamine B (RhB) dye in an aerated aqueous solution can undergo an effective photocatalytic stepwise N-deethylation process under visible light irradiation, and dioxygen is reduced to hydrogen peroxide by the reducedSiW12 4-. This provides the potential for moving polyoxometalate-based photocatalytic processes from the near-UV into the visible region of the spectrum.     

Education by Teaching Analytical Chemistry in Romania

A review is given on the history of the development of analytical chemistry in Romania, its present role in University teaching, and on measures that are planned in order to improve teaching and education.Received January 12, 2003; accepted March 7, 2003 Published online July 16, 2003     

The effect of implementation of the ISO 9000 on customer complaints; a 5-year follow-up study in a regional laboratory.

Although the importance of quality management in the medical laboratory has been emphasized, we are unaware of any interventional studies demonstrating benefits of implementation of recommendations of the International Standards Organization (ISO). In the following 5-year follow-up study, we implemented quality management as stipulated by the ISO, received a certificate of approval, and determined how the program affected customer complaints. From 1997 to 2001 there was only a slight decrease in the number of customer complaints, but a significant continuing downward trend in the proportion of justified complaints (chi-squared test, p<0.001). In fact in 2001 the proportion of justified complaints had decreased by nearly 80% (relative risk, 0.22; 95% confidence interval, 0.09–0.52)), to only 10.9% of the total complaints. We conclude that the use of the ISO 9000 along with good laboratory practice resulted in a significant decrease in the proportion of justified complaints.     

Development of a tandem cyclization mediated by samarium(II) iodide: sequential intramolecular conjugate addition/nucleophilic acyl substitution

The development of a one-pot tandem intramolecular conjugate addition/nucleophilic acyl substitution using samarium(II) iodide is reported. The reaction relies on the reagent’s unique ability to mediate both radical and anionic pathways, which are likely integral to the mechanism of this transformation. The tricyclic hemiacetal product was formed in good yield, with excellent diastereoselectivity, and its structure was verified by X-ray crystallographic analysis.     

Characterization of distribution of pi-electrons amongst benzenoid rings for Randić’s “algebraic” Kekulé structures

For benzenoid hydrocarbons the distribution of pi-electrons amongst rings is characterized in the context of Randis mode of assignment attending to the different Kekulé structures. In particular the mean and mean deviation from the mean are considered, and the benzenoids which achieve maximum deviation are identified.     

Crystal structure of (1rs, 14sr, 17rs, 18rs)-2,20-dioxa-17-methyltricyclo [16,3,0,0] heneicosa-15-ene-3,19,21-trione; a macrocyclic lac

An X-ray study of the major product of the intramolecular Diels-Alder reaction of the diene-anhydride (2) has confirmed it as being the desired cytochalasan analogue (3). In particular the cyclisation has been regioselective, and has taken place via the endo transition state to generate the adduct with the correct relative configurations at the four chiral centres. Details of the conformational geometry of (3) are discussed.