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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
22
pubmed:dateCreated
2008-5-29
pubmed:abstractText
The Candida albicans Fitness Test, a whole-cell screening platform, was used to profile crude fermentation extracts for novel antifungal natural products with interesting mechanisms of action. An extract with intrinsic antifungal activity from the fungus Fusarium larvarum displayed a Fitness Test profile that strongly implicated mRNA processing as the molecular target responsible for inhibition of fungal growth. Isolation of the active components from this sample identified a novel class of isoxazolidinone-containing natural products, which we have named parnafungins. These natural products were isolated as an interconverting mixture of four structural- and stereoisomers. The isomerization of the parnafungins was due to a retro-Michael ring-opening and subsequent reformation of a xanthone ring system. This interconversion was blocked by methylation of an enol moiety. Structure elucidation of purified parnafungin derivatives was accomplished by X-ray crystallography and NMR analysis. The biochemical target of these natural products has been identified as the fungal polyadenosine polymerase. Parnafungins demonstrated broad spectrum antifungal activity with no observed activity against gram-positive or gram-negative bacteria. The intact isoxazolidinone ring was required for antifungal activity. In addition, the natural products were efficacious in a mouse model of disseminated candidiasis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
4
pubmed:volume
130
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7060-6
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Isolation and structure elucidation of parnafungins, antifungal natural products that inhibit mRNA polyadenylation.
pubmed:affiliation
Natural Products Chemistry, Infectious Diseases, and Process Research, Merck Research Laboratories, Merck and Company, P.O. Box 2000, Rahway, New Jersey 07065, USA. craig_parish@merck.com
pubmed:publicationType
Journal Article