Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1990-2-2
pubmed:abstractText
The amatoxins, highly toxic components of Amanita mushrooms, strongly inhibit the DNA-dependent RNA polymerase II (or B) in eukaryotic cell nuclei. For optimal binding to the enzyme a gamma-hydroxyisoleucine side chain in the 3-position is important as in gamma-amanitin (compound 1), where the OH-group is bound in the [S]-configuration. Amanullin, a non-toxic component, having an oxygen-free isoleucine side chain no. 3, exhibits an inhibitory effect on RNA polymerase II about two orders of magnitude smaller than that of gamma-amanitin. An equal, relatively weak, inhibitory effect has previously been found with the synthetically obtained Ile3-analog 7. In the present paper the synthesis of an analog (2) bearing a gamma-hydroxyl group in the isoleucine side chain is described. The compound was found to have about the same inhibitory effect on RNA polymerase II from Drosophila embryos as amanullin and the Ile3-analog 7. Structure analysis by X-ray diffraction revealed that the hydroxyl group at the -carbon atom of side chain-3 has the [R]-configuration, the new analog thus being -deoxo[( )-hydroxy-[Ile3]-amaninamide. It follows that the [S]-configuration of this chiral center is a prerequisite to maximal toxicity. Crystallographic data demonstrating great similarity between the peptide backbones of the new analog and those of natural amatoxins are given.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0367-8377
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
222-8
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Structure-toxicity relationships in the amatoxin series. Synthesis of S-deoxy[gamma(R)-hydroxy-Ile3]-amaninamide, its crystal and molecular structure and inhibitory efficiency.
pubmed:affiliation
Department of Pharmaceutical Studies, University La Sapienza, Rome, Italy.
pubmed:publicationType
Journal Article