Asymmetric enamine catalysis.

Cyanines during the 1990s: A Review

Microwave assisted organic reactions

2,5-Diketopiperazines: synthesis, reactions, medicinal chemistry, and bioactive natural products.

The formation of mitotically derived spores, called conidia, is a common reproductive mode in filamentous fungi, particularly among the large fungal class Ascomycetes. Asexual sporulation strategies are nearly as varied as fungal species; however, the formation of conidiophores, specialized multicellular reproductive structures, by the filamentous fungus Aspergillus nidulans has emerged as the leading model for understanding the mechanisms that control fungal sporulation. Initiation of A. nidulans conidipohore formation can occur either as a programmed event in the life cycle in response to intrinsic signals or to environmental stresses such as nutrient deprivation. In either case, a development-specific set of transcription factors is activated and these control the expression of each other as well as genes required for conidiophore morphogenesis. Recent progress has identified many of the earliest-acting genes needed for initiating conidiophore development and shown that there are at least two antagonistic signaling pathways that control this process. One pathway is modulated by a heterotrimeric G protein that when activated stimulates growth and represses both asexual and sexual sporulation as well as production of the toxic secondary metabolite, sterigmatocystin. The second pathway apparently requires an extracellular signal to induce sporulation-specific events and to direct the inactivation of the first pathway, removing developmental repression. A working model is presented in which the regulatory interactions between these two pathways during the fungal life cycle determine whether cells grow or develop.

/pdf/asexual-sporulation-in-aspergillus-nidulans-3pdjxo10gt.pdf

Asexual Sporulation in Aspergillus nidulans

Les auteurs decrivent la synthese enantioselective de la (+)-brefeldine C. Cette synthese utilise une amine chirale: la (t-butyl-2 methyl-4 phenyl-5) oxazolidine

Synthetic studies in the brefeldin series: asymmetric enamine-enal cycloaddition and intramolecular Nozaki reactions

Structural elucidation of sporogenic fatty acid metabolites from aspergillus nidulans

Stereochemistry of the intramolecular enamine/enal (enone) cycloaddition reaction and subsequent transformations

A microscale method for identifying the monosaccharide units and their linkages in oligosaccharides is presented. Sugar components are identified by UV and CD spectroscopy of chromophoric degradation products. CD spectral data for approximately 150 different glycopyranoside components are provided for use as reference spectra in the identification of unknown derivatives. Procedures for the conversion of oligosaccharides to monosaccharide subunits bearing 4-bromobenzoate and 4-methoxycinnamate chromophores have been developed based on acetolysis/bromination reactions for glycosidic cleavage of per (bromobenzoylated) oligosaccharides. The method offers an alternative means to conventional methylation analysis of oligosaccharides.

A CD‐Spectroscopic Alternative to Methylation Analysis of Oligosaccharides: Reference Spectra for Identification of Chromophoric Glycopyranoside Derivatives

Harold V. Meyers

Papers

Synthetic studies in the brefeldin series: asymmetric enamine-enal cycloaddition and intramolecular Nozaki reactions

Structural elucidation of sporogenic fatty acid metabolites from aspergillus nidulans

Stereochemistry of the intramolecular enamine/enal (enone) cycloaddition reaction and subsequent transformations

A CD‐Spectroscopic Alternative to Methylation Analysis of Oligosaccharides: Reference Spectra for Identification of Chromophoric Glycopyranoside Derivatives

Regioselective functionalization of bicyclic piperazinedione bridgehead carbanions