Proteome analysis of Corynebacterium glutamicum.

By the use of different Corynebacterium glutamicum strains more than 1.4 million tons of amino acids, mainly L-glutamate and L-lysine, are produced per year. A project was started recently to elucidate the complete DNA sequence of this bacterium.

Transesterification reactions of parabens (alkyl 4-hydroxybenzoates) with polyols in aqueous solution.

Accelerated stability tests of aqueous solutions containing parabens and polyols were performed using concentrations similar to pharmaceutical and cosmetic formulations. Reaction products were detected in these solutions by HPLC and identified by chromatographic and spectroscopic means. Using xylitol and methylparaben as model reactants, three unknown peaks having the relation 1:2:4 were obtained together with the hydrolysis product 4-hydroxybenzoic acid.

Structural investigation of Cetrorelix, a new potent and long-acting LH-RH antagonist.

The new decapeptide SB-75 (INN: Cetrorelix) has been characterized as a potent antagonist of luteinizing-hormone releasing hormone (LH-RH). Such derivatives are of great medicinal interest owing to their potential application in areas such as hormone-dependent tumors, uterine fibroids, and in diseases and conditions which result from inappropriate hormone levels or which can be treated by suppression of estrogens. SB-75 is the subject of intensive ongoing clinical evaluation and is an accepted standard for the design of new LH-RH antagonists.

A mass spectral study of cyclophosphamide concerning a thermally induced rearrangement reaction.

The electron impact mass spectra of cyclophosphamide (1) are very sensitive towards experimental conditions in view of the kind of sample handling, the type of mass spectrometer used and the temperature of evaporation. The reason for this phenomenon is the elimination of HCl from the molecular ion by a specific 1,5-hydrogen transfer yielding an ion at m/z 224 which is structurally related to the bicyclic compound 4 with its typical fragment ions at m/z 175 and 147. Thermal excitation of the sample increases the intensity of this fragmentation pathway.

Application of chromatographic chiral stationary phases to pharmaceutical analysis. Enantiomeric purity of D-penicillamine.

The enantiomeric purity of the pharmaceutical D-penicillamine (I) has been determined by a novel high-performance liquid chromatographic technique involving the formation of 5,5-dimethylthiazolidine-4-carboxylic acid (III) by reaction of I with formaldehyde and separation of the optical antipodes by means of ligand exchange chromatography using the copper(II) complex of (2S,4R,2'RS)-4-hydroxy-1-(2'-hydroxydodecyl)proline, which is coated on a reversed-phase column. The limit of determination for the L-antipode is ca. 0.