Linked Life Data

16665189

Source:http://linkedlifedata.com/resource/pubmed/id/16665189

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2010-6-29
pubmed:abstractText
Immature seeds of apricot (Prunus armeniaca L.) were fed the native gibberellin A(5) (GA(5)) as 1- and 1,2-[(3)H]GA(5) (5.3 Curies per millimole to 16 milliCuries per millimole) at doses (42 nanograms to 10.6 micrograms per seed) 2 to 530 times the expected endogenous level. After 4 days of incubation, seeds were extracted and free [(3)H]GA-like metabolites were separated from the highly H(2)O-soluble [(3)H]metabolites. For high specific activity feeds the retention times (Rts) of radioactive peaks were compared with Rts of authentic GAs on sequential gradient-eluted --> isocratic eluted reversed-phase C(18) high performance liquid chromatography (HPLC) -radiocounting (RC). From high substrate feeds (530 and 230 x expected endogenous levels) HPLC-RC peak groupings were subjected to capillary gas chromatography-selected ion monitoring (GC-SIM), usually six characteristic ions. The major free GA metabolites of [(3)H] GA(5) were identified as GA(1), GA(3), and GA(6) by GC-SIM. The major highly water soluble metabolite of [(3)H]GA(5) at all levels of substrate GA(5) had chromatographic characteristics similar to authentic GA(1)-glucosyl ester. Expressed as a percentage of recovered radioactivity, low substrate [(3)H]GA(5) feeds (2 x expected endogenous level) yielded a broad spectrum of metabolites eluting at the Rts where GA(1), GA(3), GA(5) methyl ester, GA(6), GA(22), GA(29) (17, 14, 1.6, 7, 1.1, 0.5%, respectively) and GA glucosyl conjugates of GA(1), GA(3), GA(5), and GA(8) (33, 11, 1, 0.1%, respectively) elute. Metabolites were also present at Rts where GA glucosyl conjugates of GA(6) and GA(29) would be expected to elute (8 and 0.1%, respectively). Only 5% of the radioactivity remained as GA(5). Increasing substrate GA(5) levels increased the proportion of metabolites with HPLC Rts similar to GA(1), GA(6), and especially GA(1) glucosyl ester, primarily at the expense of metabolites with HPLC Rts similar to GA(3), GA(3)-glucosyl ester, and a postulated conjugate of GA(6). There was evidence that high doses of substrate GA(5) induced new metabolites which often, but not always, differed from GA(1), GA(3), and GA(6) in HPLC Rt. These same metabolites, when analyzed by GC-SIM yielded m/e ions the same as the M(+) and other characteristic m/e ions of the above GAs, albeit at differing GC Rt and relative intensities.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jan
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
83
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
137-42
pubmed:dateRevised
2010-9-14
pubmed:year
1987
pubmed:articleTitle
Metabolism of [H]Gibberellin A(5) by Immature Seeds of Apricot (Prunus armeniaca L.).
pubmed:affiliation
Plant Physiology Research Group, Department of Biology, The University of Calgary, Calgary, Alberta T2N 1N4 Canada.
pubmed:publicationType
Journal Article