Enantiomerically highly enriched unsaturated β-ketoesters bearing a quaternary stereocenter can be utilized as building blocks for the synthesis of natural occurring terpenes, i. a., trisporic acid and its derivatives. An advanced building block has been synthesized in a short reaction sequence, which involves an oxidative allylic rearrangement initiated by pyridinium dichromate (PDC) as the ke...

Abstract Chemical oxygen demand (COD) is one of the critical environmental parameters in determining organic matter water matrices. The conventional dichromate method employs hazardous reagents and heat reflux. In order to reduce waste, several alternative methods have been proposed replace dichromate. photoelectrochemical COD (PeCOD) has become a promising for being less time-consuming, enviro...

BACKGROUND Exposure to chromium during electroplating is a recognised though poorly characterised cause of occupational asthma. The first series of such patients referred to a specialist occupational lung disease clinic is reported. METHODS The diagnosis of occupational asthma was made from a history of asthma with rest day improvement and confirmed by specific bronchial provocation testing w...

The basis of the method is the measurement of the color change produced by the reducing action of fatty acid or cholesterol on a sulfuric acid-dichromate mixture. This reaction has been used in several ways for the determination of fatty acids and other organic material. Bang (1) made it the basis of a micromethod by titrating the excess of dichromate with starch-iodine and thiosulfate. In this...

The basis of the method is the measurement of the color change produced by the reducing action of fatty acid or cholesterol on a sulfuric acid-dichromate mixture. This reaction has been used in several ways for the determination of fatty acids and other organic material. Bang (1) made it the basis of a micromethod by titrating the excess of dichromate with starch-iodine and thiosulfate. In this...

SEROTONIN (5-hydroxytryptamine, 5-HT) in blood is transported almost exclusively by circulating platelets.1 Early biochemical and pharmacologic studies demonstrated that most of the 5-HT was found in granules present in platelet hyaloplasm.2” Recently, several laboratories have suggested that platelet serotonin is concentrated within a specific type of platelet organelle, the dense body58 ( Fig...

Gas-chromatographic methods for ethanol quantitation provide greater specificity than traditional oxidimetric methods. The specificity of oxidimetric methods such as those of Kozelka-Hine (1) and Widmark (2) rely on the arguments that: (a) the sample came from a living person and (b) drugs or chemicals that would appreciably react with potassium dichromate could not be expected to be present in...

background the increasing use of herbal drugs and their easy availability have necessitated the use of mutagenicity tests to analyze their toxicity and safety. objectives the aim of this study was to determine the in vitro mutagenicity of artemisia draconculus l., a herbal drug, by performing single cell gel electrophoresis (scge). materials and methods in this study, we obtained a herbal drug ...

The asymmetric unit of the title compound, [Ni(C(12)H(8)N(2))(3)][Cr(2)O(7)]·4H(2)O, contains one cation, one anion and four water mol-ecules, three of which are disordered over two sites with equal occupancies. In the cation, the metal centre is coordinated by six N atoms from three 1,10-phenanthroline ligands in a distorted octa-hedral geometry. The [Cr(2)O(7)](2-) anion exhibits a staggered ...