Publications by authors named "Ulrike Riese"

A new pyridone alkaloid, (+)-N-deoxymilitarinone A (1), was isolated from Paecilomyces farinosus RCEF 0097 along with the related metabolites, militarinone D and militarinone B. The sterol 22E,4R-ergosta-7,22-diene-3beta,5alpha,6beta,9alpha-tetraol was also identified. The structures were established by spectroscopic methods, in particular with the aid of extensive NMR experiments.

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Two new yellow pigments, farinosones A (1) and B (2), were isolated from the mycelial extract of the entomogenous fungal strain Paecilomyces farinosus RCEF 0101, together with farinosone C (3), a new metabolite derived from an early step of pyridone alkaloid biosynthesis. The structures were determined by spectroscopic means, in particular by extensive NMR experiments. Compounds 1 and 3 induced neurite outgrowth in the PC-12 cell line at concentrations of 50 microM, while compound 2 was inactive.

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The fungal metabolite militarinone A (MILI A) promotes neurite outgrowth in PC12 cells. This study was conducted to investigate the signaling pathways involved in the cellular differentiation processes induced by the compound, with a focus on cascades implicated with nerve growth factor (NGF)-mediated neuritogenesis. MILI A possessed pronounced amphiphilic properties.

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An assay for the HPLC-based search for monoamine oxidase-A (MAO-A) inhibitors in plant extracts was established. It combines human recombinant MAO-A, expressed as GST-fusion protein in yeast, with a kinetic measurement of the conversion of kynuramine to 4-hydroxyquinoline. Substrate selectivity and kinetic parameters of the GST-fusion protein were comparable to the wild-type enzyme.

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Three yellow pigments were isolated from a mycelial extract of the entomopathogenic fungus Paecilomyces militaris. With the aid of spectroscopic means, one compound was identified as a new pyridone alkaloid, militarinone D (1). The two other metabolites were characterized as two novel 3-acyl tetramic acids, militarinones B (2) and C (3).

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The molecular mechanisms underlying the regulation of interleukin (IL)-10 transcription in monocytic cells by various stimuli during inflammation and the stress reaction are not fully understood. Recently, we provided evidence that stress-induced IL-10 promoter activation in monocytic cells is mediated by catecholamines via a cAMP-dependent signaling pathway including CREB/ATF (cAMP-responsive element binding protein/activating transcription factor) binding to two CRE motifs. However, the mutation of these sites diminished cAMP responsiveness by only 50%, suggesting a role for additional transcription factors and elements in the cAMP-dependent regulation of the human IL-10 promoter.

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Cold-pressed, non-raffinated evening primrose oil was found to contain lipophilic radical scavengers. A highly enriched fraction of these compounds could be obtained from the oil by extraction with aqueous ethanol and subsequent liquid-liquid partitioning with petroleum. LC-DAD-MS analysis revealed that the fraction contained three aromatic compounds with identical UV and ESI-MS spectra.

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To evaluate the invasive potential of early tumorous lesions of the breast, especially DCIS, we have analyzed semiquantitative telomerase activity in well defined microdissected tissue areas from malignant or benign breast lesions from 145 patients. In order to prove the relationship to cell cycle defects, p53 and p21 proteins were analyzed in corresponding cryostat sections by immunohistochemistry. Telomerase activity was detected in 3 (33.

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Unusual, highly symmetrical cubes are formed by the dodecameric cationic phosphoraneiminato complexes of copper(I) and silver(I) [M (NPEt ) ] , in which the metal atoms occupy the edges and the N atoms of NPEt groups the corners of the cube (see figure). The structures can be understood as molecular sections of the Cu N structure, which is inverse to the ReO -type structure.

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