Stereochemistry and conformations of natural 1,2-epoxy-guaianolides based on 1D and 2D NMR data and semiempirical calculations
Samo za registrovane korisnike
2008
Autori
Trifunović, Snežana S.Milosavljević, Slobodan M.
Vajs, Vlatka
Macura, Slobodan
Todorović, Nina
Članak u časopisu (Objavljena verzija)
Metapodaci
Prikaz svih podataka o dokumentuApstrakt
From detailed study of 1D 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 H-1 and 13 C 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 1 D 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 (AM1 and PM3 methods), performed in order to gain additional information regarding conformations, resulted in three geometries of in...vestigated lactones. Even so, the conformations derived from the NMR data agreed well with those calculated by semiempirical methods. Copyright (C) 2008 John Wiley & Sons, Ltd.
Ključne reči:
H-1 NMR / C-13 NMR / 2D NMR / sesquiterpene lactones / guaianolide-1,2-epoxychlorohydrins / conformational analysis / Achillea LIzvor:
Magnetic Resonance in Chemistry, 2008, 46, 5, 427-431Izdavač:
- Wiley, Hoboken
Finansiranje / projekti:
- Sekundarni metaboliti samoniklih, lekovitih biljaka: izolovanje, karakterizacija i biloška aktivnost (RS-142053)
DOI: 10.1002/mrc.2193
ISSN: 0749-1581
PubMed: 18306444
WoS: 000255250600004
Scopus: 2-s2.0-43749113808
Kolekcije
Institucija/grupa
Hemijski fakultet / Faculty of ChemistryTY - JOUR AU - Trifunović, Snežana S. AU - Milosavljević, Slobodan M. AU - Vajs, Vlatka AU - Macura, Slobodan AU - Todorović, Nina PY - 2008 UR - https://cherry.chem.bg.ac.rs/handle/123456789/935 AB - From detailed study of 1D 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 H-1 and 13 C 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 1 D 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 (AM1 and PM3 methods), performed in order to gain additional 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. Copyright (C) 2008 John Wiley & Sons, Ltd. PB - Wiley, Hoboken T2 - Magnetic Resonance in Chemistry T1 - Stereochemistry and conformations of natural 1,2-epoxy-guaianolides based on 1D and 2D NMR data and semiempirical calculations VL - 46 IS - 5 SP - 427 EP - 431 DO - 10.1002/mrc.2193 ER -
@article{ author = "Trifunović, Snežana S. and Milosavljević, Slobodan M. and Vajs, Vlatka and Macura, Slobodan and Todorović, Nina", year = "2008", abstract = "From detailed study of 1D 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 H-1 and 13 C 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 1 D 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 (AM1 and PM3 methods), performed in order to gain additional 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. Copyright (C) 2008 John Wiley & Sons, Ltd.", publisher = "Wiley, Hoboken", journal = "Magnetic Resonance in Chemistry", title = "Stereochemistry and conformations of natural 1,2-epoxy-guaianolides based on 1D and 2D NMR data and semiempirical calculations", volume = "46", number = "5", pages = "427-431", doi = "10.1002/mrc.2193" }
Trifunović, S. S., Milosavljević, S. M., Vajs, V., Macura, S.,& Todorović, N.. (2008). Stereochemistry and conformations of natural 1,2-epoxy-guaianolides based on 1D and 2D NMR data and semiempirical calculations. in Magnetic Resonance in Chemistry Wiley, Hoboken., 46(5), 427-431. https://doi.org/10.1002/mrc.2193
Trifunović SS, Milosavljević SM, Vajs V, Macura S, Todorović N. Stereochemistry and conformations of natural 1,2-epoxy-guaianolides based on 1D and 2D NMR data and semiempirical calculations. in Magnetic Resonance in Chemistry. 2008;46(5):427-431. doi:10.1002/mrc.2193 .
Trifunović, Snežana S., Milosavljević, Slobodan M., Vajs, Vlatka, Macura, Slobodan, Todorović, Nina, "Stereochemistry and conformations of natural 1,2-epoxy-guaianolides based on 1D and 2D NMR data and semiempirical calculations" in Magnetic Resonance in Chemistry, 46, no. 5 (2008):427-431, https://doi.org/10.1002/mrc.2193 . .