Stereochemistry and conformations of natural 1,2-epoxy-guaianolides based on 1D and 2D NMR data and semiempirical calculations
Само за регистроване кориснике
2008
Чланак у часопису (Објављена верзија)
Метаподаци
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From 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 investi...gated lactones. Even so, the conformations derived from the NMR data agreed well with those calculated by semiempirical methods. Copyright
Кључне речи:
2D NMR / 13C NMR / 1H NMR / Achillea L / Conformational analysis / Guaianolide-1,2-epoxychlorohydrins / Sesquiterpene lactonesИзвор:
Magnetic Resonance in Chemistry, 2008, 46, 5, 427-431Финансирање / пројекти:
- Секундарни метаболити самониклих, лековитих биљака: изоловање, карактеризација и билошка активност (RS-MESTD-MPN2006-2010-142053)
DOI: 10.1002/mrc.2193
ISSN: 0749-1581
PubMed: 18306444
WoS: 000255250600004
Scopus: 2-s2.0-43749113808
Институција/група
IHTMTY - JOUR AU - Trifunović, Snežana AU - Milosavljević, Slobodan AU - Vajs, Vlatka AU - Macura, Slobodan AU - Todorović, Nina PY - 2008 UR - https://cer.ihtm.bg.ac.rs/handle/123456789/476 AB - From 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. Copyright 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 and Milosavljević, Slobodan and Vajs, Vlatka and Macura, Slobodan and Todorović, Nina", year = "2008", abstract = "From 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. Copyright", 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., Milosavljević, S., 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, 46(5), 427-431. https://doi.org/10.1002/mrc.2193
Trifunović S, Milosavljević S, 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, Milosavljević, Slobodan, 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 . .