Computational Approaches for the Prediction of Environmental Transformation Products: Chlorination of Steroidal Enones.

There is growing interest in the fate and effects of transformation products generated from emerging pollutant classes, and new tools that help predict the products most likely to form will aid in risk assessment. Here, using a family of structurally related steroids (enones, dienones, and trienones), we evaluate the use of density functional theory to help predict products from reaction with chlorine, a common chemical disinfectant. For steroidal dienones (e.

Broomeanamides: Cyclic Octapeptides from an Isolate of the Fungicolous Ascomycete from India.

The genus comprises fungi that colonize basidiomata of wood-inhabiting fungi, including important forest pathogens. Studies of fermentation cultures of an isolate (TFC201724) collected on the foothills of Himalayas, and closely related to isolates from Europe, led to the identification of a new cyclic octapeptide along with two closely related analogues (-) and four dioxopiperazines (-). The structure of the lead compound, broomeanamide A (), was assigned mainly by analysis of 2D NMR and HRESIMS data.

Anti-cryptococcal activity of preussolides A and B, phosphoethanolamine-substituted 24-membered macrolides, and leptosin C from coprophilous isolates of Preussia typharum.

Cryptococcus neoformans is a serious human pathogen with limited options for treatment. We have interrogated extracts from fungal fermentations to find Cryptococcus-inhibiting natural products using assays for growth inhibition and differential thermosensitivity. Extracts from fermentations of four fungal strains from wild and domestic animal dung from Arkansas and West Virginia, USA were identified as Preussia typharum.

Sphaerostilbellins, New Antimicrobial Aminolipopeptide Peptaibiotics from .

is a mycoparasitic fungus that can be found parasitizing wood-decay basidiomycetes in the southern USA. Organic solvent extracts of fermented strains of exhibited potent antimicrobial activity, including potent growth inhibition of human pathogenic yeasts and the respiratory pathogenic fungus , and the Gram-positive bacterium . Bioassay-guided separations led to the purification and structure elucidation of new peptaibiotics designated as sphaerostilbellins A and B.

Photolysis of Trenbolone Acetate Metabolites in the Presence of Nucleophiles: Evidence for Metastable Photoaddition Products and Reversible Associations with Dissolved Organic Matter.

Photolysis of trenbolone acetate (TBA) metabolites in the presence of various nitrogen-, sulfur-, or oxygen-containing nucleophiles (, azide, ammonia, or thiosulfate, respectively) results in rapid (half-lives ∼20-60 min), photochemically induced nucleophile incorporation across the parent steroid's trienone moiety. The formation of such nucleophile adducts limits formation of photohydrates, suggesting competition between the nucleophile and water for photochemical addition into the activated steroid structure. Analogous to previously reported photohydration outcomes, LC/MS analyses suggest that such photonucleophilic addition reactions are reversible, with more rapid elimination rates than thermal dehydration of photohydrates, and regenerate parent steroid structures.