Afurika nanbu ni okeru gengo no kiki - Matthias Brenzinger-shi ni kiku [Language Endangerment ion Southern Africa - Interview with Matthias Brenzinger]

Viridicatumtoxins, which belong to a rare class of fungal tetracycline-like mycotoxins, were subjected to comprehensive spectroscopic and chemical analysis, leading to reassignment/assignment of absolute configurations and characterization of a remarkably acid-stable antibiotic scaffold. Structure activity relationship studies revealed exceptional growth inhibitory activity against vancomycin-resistant Enterococci (IC₅₀ 40 nM), >270-fold more potent than the commercial antibiotic oxytetracycline

Trichodermides A–E: New Peptaibols Isolated from the Australian Termite Nest-Derived Fungus <i>Trichoderma virens</i> CMB-TN16

Chemical analysis of a fermentation of the Australian termite nest-derived fungus <i>Trichoderma virens</i> CMB-TN16 yielded five new acyclic nonapeptides, trichodermides A–E (<b>1</b>–<b>5</b>). Amino acid residues, configurations, and sequences were determined by a combination of spectroscopic (NMR and MS-MS) and chemical (C₃ Marfey’s) methods. The trichodermides adhere to the sequence homology pattern common to <i>Trichoderma</i> 11 amino acid residue peptaibols; however, unlike other peptaibols the trichodermides do not exhibit antibacterial or antifungal activity and exhibit low to no cytotoxicity against mammalian cells. This variability in biological activity highlights the importance of knowing both planar structures and absolute configurations when interpreting structure–activity relationships

C₃ and 2D C₃ Marfey’s Methods for Amino Acid Analysis in Natural Products

We validate the improved resolution and sensitivity of the C₃ Marfey’s method, including an ability to resolve all Ile isomers, against an array of amino acids commonly encountered in natural products and by comparison to an existing Marfey’s method. We also describe an innovative 2D C₃ Marfey’s method as an analytical approach for determining the regiochemistry of enantiomeric amino acid residues in natural products. The C₃ and 2D C₃ Marfey’s methods represent valuable tools for probing and defining the stereocomplexity of hydrolytically accessible amino acid residues in natural products