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dc.creatorTrifunović, Snežana
dc.creatorMilosavljević, Slobodan
dc.creatorVajs, Vlatka
dc.creatorMacura, Slobodan
dc.creatorTodorović, Nina
dc.date.accessioned2019-01-30T17:19:03Z
dc.date.available2019-01-30T17:19:03Z
dc.date.issued2008
dc.identifier.issn0749-1581
dc.identifier.urihttp://cer.ihtm.bg.ac.rs/handle/123456789/476
dc.description.abstractFrom detailed study of ID and 2D NMR spectra of ten natural 1,2-epoxyguaianolides (bis-1,2:3,4-epoxyguaianolides and guaianolide-1,2- epoxychlorohydrins), we identified general spectral traits helpful for stereochemical assignment of such sesquiterpene lactones. We found that the chemical shifts of certain 1H and 13C nuclei are consistently dependent on the configuration of 1,2-epoxy-ring which could be used as a simple rule for establishing this configuration. Then, from 1D and 2D (COSY, NOESY, HMQC, HMBC) NMR data, applying the observed rule, the structure and stereochemistry of two new, diastereomeric guaianolide-1,2- epoxychlorohydrins, isolated from Achillea serbica, are determined. The NMR data, namely, nuclear overhauser enhancement (NOE) correlations, pointed out two conformations of guaianolide's cycloheptane ring. The semiempirical calculations (AMI and PM3 methods), performed inordertogainadditional information regarding conformations, resulted in three geometries of investigated lactones. Even so, the conformations derived from the NMR data agreed well with those calculated by semiempirical methods. Copyrighten
dc.relationinfo:eu-repo/grantAgreement/MESTD/MPN2006-2010/142053/RS//
dc.rightsrestrictedAccess
dc.sourceMagnetic Resonance in Chemistry
dc.subject2D NMRen
dc.subject13C NMRen
dc.subject1H NMRen
dc.subjectAchillea Len
dc.subjectConformational analysisen
dc.subjectGuaianolide-1,2-epoxychlorohydrinsen
dc.subjectSesquiterpene lactonesen
dc.titleStereochemistry and conformations of natural 1,2-epoxy-guaianolides based on 1D and 2D NMR data and semiempirical calculationsen
dc.typearticle
dc.rights.licenseARR
dcterms.abstractМацура, С.; Милосављевић, С.; Трифуновић, С.; Тодоровић, Нина; Вајс, В.;
dc.citation.volume46
dc.citation.issue5
dc.citation.spage427
dc.citation.epage431
dc.citation.other46(5): 427-431
dc.citation.rankM22
dc.identifier.pmid18306444
dc.identifier.doi10.1002/mrc.2193
dc.identifier.rcubConv_4155
dc.identifier.scopus2-s2.0-43749113808
dc.identifier.wos000255250600004
dc.type.versionpublishedVersion


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