Abstract
A new antibacterial dioxopiperazine, dehydroxybisdethiobis(methylthio)gliotoxin (1), and the previously described bisdethiobis(methylthio)gliotoxin (2) and gliotoxin (3), have been isolated from the broth of a marine-derived fungus of the genus Pseudallescheria. The structure and absolute stereochemistry of the new compound was assigned on the basis of NMR and CD experiments. Compounds 1 to approximately 3 exhibit potent antibacterial activity against the methicillin-resistant and multidrug-resistant Staphylococcus aureus with MIC values of 31.2, 31.2, and 1.0 microg/ml, respectively. Compound 3 also exhibited a significant radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC50 value of 5.2 microM.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Anti-Bacterial Agents / chemistry
-
Anti-Bacterial Agents / isolation & purification
-
Anti-Bacterial Agents / pharmacology*
-
Circular Dichroism
-
Free Radical Scavengers / isolation & purification
-
Free Radical Scavengers / pharmacology
-
Gliotoxin / analogs & derivatives*
-
Gliotoxin / chemistry
-
Gliotoxin / isolation & purification
-
Gliotoxin / pharmacology*
-
Magnetic Resonance Spectroscopy
-
Microbial Sensitivity Tests
-
Molecular Structure
-
Phaeophyceae / microbiology
-
Pseudallescheria / isolation & purification
-
Pseudallescheria / metabolism*
-
Seawater / microbiology
-
Staphylococcus aureus / drug effects*
Substances
-
Anti-Bacterial Agents
-
Free Radical Scavengers
-
dehydroxybisdethiobis(methylthio)gliotoxin
-
Gliotoxin