Linked Life Data

19415927

Source:http://linkedlifedata.com/resource/pubmed/id/19415927

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2009-5-6
pubmed:abstractText
Compositional analysis by liquid chromatography/mass spectrometry of triterpenoid glycosides in different tomato cultivars, ripening stages, and parts of fruits showed that alpha-tomatine was generally most abundant in the flesh of the mature green stage, whereas esculeoside A was predominant in that of the red ripe stage. The sum of these glycoalkaloids was more or less constant, suggesting that alpha-tomatine is converted to esculeoside A during ripening. Besides various substitutions, the C22alphaN --> C22betaN isomerization is an important step in this transformation. By quantum chemical calculations it was shown that hydroxylation at C27 of the triterpenoidal skeleton is the driving force behind the isomerization. For the protonated form of the glycoalkaloid (predominant at the pH of tomato tissue), the C22betaN configuration becomes more favorable than that of C22alphaN, through the extra energy provided by the hydrogen bond between the protonated nitrogen and the lone pair of the oxygen of the C27-OH.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1520-5118
pubmed:author
pubmed:issnType
Electronic
pubmed:day
13
pubmed:volume
57
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3786-91
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
C22 isomerization in alpha-tomatine-to-esculeoside A conversion during tomato ripening is driven by C27 hydroxylation of triterpenoidal skeleton.
pubmed:affiliation
Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
pubmed:publicationType
Journal Article