Linked Life Data

11559051

Source:http://linkedlifedata.com/resource/pubmed/id/11559051

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2001-9-17
pubmed:abstractText
The use of hair as a matrix for the determination of a history of drug abuse is becoming increasingly widespread. Melanin has been shown to play a key role in the incorporation of drugs in hair. The mechanism of this incorporation and the nature of the interaction remains poorly understood. Cationic drugs, such as amphetamine, are thought to be ionically bound to melanin; however, their inextricability has led to the suggestion that they may be covalently bound to a great degree. Identification of covalent adducts remains elusive due to the insoluble polymeric nature of melanin. We succeeded in identifying several such adducts by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF) analysis of the products of in vitro synthesis of melanin in the presence of amphetamine. Amphetamine was incubated with L-DOPA and mushroom tyrosinase under a stream of oxygen. After 1 h, a signal at m/z 281.1324 (n = 1, R = H) was observed. After 2 h, the major adduct mass visible in the spectrum was at m/z 470.1074. This appeared to be derived from the mono-decarboxylation of a minor adduct at m/z 514.1245 (n = 2, R = CO(2)H). A totally decarboxylated adduct was also observed at m/z 426.1448 (n = 2, R = H). These were identified as amphetamine adducts of indole quinones. Corroboration of their identity was obtained by observing the mass shifts with deuterated L-DOPA and amphetamine analogues. Accurate mass measurements using the reflectron mode of the MS showed that the smaller adduct was within 14 ppm, and the larger adducts were within 70 ppm of their theoretical monoisotopic masses. Postsource decay experiments agreed with our structural assignments.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0893-228X
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1339-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Amphetamine adducts of melanin intermediates demonstrated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
pubmed:affiliation
Program in Molecular and Environmental Toxicology, School of Pharmacy, The University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.