Fast identification of mycobacterium species by GC analysis with trimethylsulfonium hydroxide (TMSH) for transesterification

Trimethylsulfonium hydroxide (TMSH) reproducibly converts fatty acids bound in, e.g., biomolecules such as phospholipids and/or glycerides, into the corresponding fatty acid methyl esters (FAMEs). The transesterification can be performed at room temperature in a fast single step reaction. Surprisingly, secondary alcohols and mycolic acid cleavage products (MACPs) are also released from mycobacteria under these conditions. The complex reaction mixtures containing FAMEs, MACPs, and secondary alcohols can easily be separated by high resolution temperature-programmed capillary GC. Different species of mycobacteria give rise to characteristic chromatographic patterns and the amount of lipids from a single colony of mycobacteria is sufficient for reliable identification of the bacteria. The profiles of the chromatograms match well those obtained from other sample preparation techniques. The TMSH method of identification of mycobacteria from the patterns of the gas chromatograms is faster and more sensitive than conventional methods, which also involve transesterification. The identification of mycobacterial species by microbiological culture techniques is difficult to perform and requires several weeks.     

Heat capacity measurements of SnSe and SnSe2

The heat capacities of SnSe and SnSe₂ were measured in the temperature range 230–580 K using a computer interfaced differential scanning calorimeter. From these measurements, the Debye temperatures of SnSe and SnSe₂ were calculated as a function of temperature. An estimated Debye temperature of 220 K for SnSe was used to calculate the absolute entropy of SnSe at 298 K to be 85.2 ± 6.0 J K^?1 mole^?1. In the light of other work, the suitability of Debye temperatures for estimating low temperature heat capacities of SnSe₂ is questioned.     

Über die komplexe Dielektrizitätskonstante von Tellur bei Mikrowellenfrequenzen

Zeitschrift für Physik A Hadrons and nuclei - Messungen der komplexen Dielektrizitätskonstanten an Tellureinkristallen zwischen ?170 °C und Zimmertemperatur geben für den...     

Zur Kenntnis der Dampfdruckkurve von Chlordioxid

Ohne ZusammenfassungMit 3 AbbildungenHerrn Prof. Dr.O. Kratky zum 60. Geburtstag.     

Ger?te zum Arbeiten mit wasserempfindlichen Substanzen

Ohne Zusammenfassung     

Meilenstein Salicylsäuresynthese

In early Christian times treating the sick was considered as blasphemy, and it had only to be in the hands of the Almighty alone (“Do not meddle in the Almighty's creation”). But by and by people did not take diseases as god‐given, and tried and learned to combat them. For some millenniums only natural “remedies” like herbs, animal, and inorganic products were available. Finally, at the beginning of the 19th century it became possible to isolate pure natural substances from herbs, characterize, and modify them by partial synthesis, in order to optimize efficacy, resorption and side effects.On January 2nd 1874 the total chemical synthesis of drugs in industrial scale began in a mansion in the city of Dresden, when Hermann Kolbe jointly with Rudolf Schmitt and Friedrich von Heyden produced Salicylic acid from phenol and carbon dioxide.Until then this drug substance could only be made from willow bark or the plant Spirea ulmaria. Today many substances of natural origin as well of completely newly structured compounds can be made by total synthesis. Biotechnology, and Gene technology are broadening the methods to prepare new drugs.