Structure of cytochalasin E, a toxic metabolite of Aspergillus clavatus

Identification of a Hybrid PKS/NRPS Required for Pseurotin A Biosynthesis in the Human Pathogen Aspergillus fumigatus

“…However, it is often the case that fungal secondary-metabolic genes are transcribed at very low levels; this makes detection of products difficult. Species of A. clavatus are also known to produce cytochalasin E, [26] which like pseurotin A includes a g-lactam moiety. Cytochalasin E is derived from phenylalanine, methionine, and acetate or malonate, so it is possible that the putative orthologous cluster of A. clavatus is responsible for cytochalasin biosynthesis.…”

The structure of chaetoglobosin A: a novel use of quartet invariants

“…All H atoms were found and the structure was refined by a blocked least-squares approach, with isotropic thermal parameters for the H atoms and anisotropic parameters for the others, to an R factor of 0.033. While it was expected that the absolute stereochemistry of chaetoglobosin A would be similar to that of the 11-cytochalasins to which it is chemically related and whose absolute configuration is known (Tsukuda & Koyama, 1972;Buchi, Kitaura, Yuan, Wright, Clardy, Demain, Glinsukin, Hunt & Wogan, 1973), there is no direct evidence and, therefore, both possible enantiomers were refined using anomalous-scattering factors for C, N and O. The expected enantiomer gave the lower R factor but the difference was not significant.…”

Aspergillus Toxins Other Than Aflatoxin

“…A recent report implicated cytochalasin Ε from Aspergillus clavatus to human mortality from ingestion of mold-damaged rice (74,75). Cyto chalasin Ε (Structure XIX) contained mono-substituted aromatic, sec ondary amide, epoxide, ketone, and alkyl vinyl carbonate moieties (75).…”

“…Cyto chalasin Ε (Structure XIX) contained mono-substituted aromatic, sec ondary amide, epoxide, ketone, and alkyl vinyl carbonate moieties (75).…”

“…two exchangeable protons appeared at δ 6.93 (NH proton on C-2) and The corrected structure and stereochemistry were obtained via single crystal x-ray diffraction analysis (75). Cytochalasin Ε reportedly killed rats within a few hours after dosing.…”