Ascorbigen A—NMR identification

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F19%3A00507455" target="_blank" >RIV/61388963:_____/19:00507455 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/67985858:_____/19:00507455 RIV/61389030:_____/19:00507455 RIV/00216224:14740/19:00111526

Výsledek na webu

<a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/mrc.4890" target="_blank" >https://onlinelibrary.wiley.com/doi/abs/10.1002/mrc.4890</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/mrc.4890" target="_blank" >10.1002/mrc.4890</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Ascorbigen A—NMR identification

Popis výsledku v původním jazyce

The connectivities of all atoms in ascorbigen A, an important metabolite, were determined unambiguously for the first time. The connectivity between carbon atoms was established by 2D INADEQUATE, and one‐bond 13C–13C coupling constants were determined for all pairs of directly connected carbon atoms except for two strongly coupled carbon pairs. The 13C–13C coupling in one of the pairs was proved by a modification of standard INADEQUATE, however, the signals from the other pair were too weak to be observed. The connectivity within the two strongly coupled C–C pairs was confirmed by a combination of COSY and gHSQC, the latter experiment also identified all C–H bonds. The proton nuclear magnetic resonance (1H NMR) spectra in dry dimethyl sulfoxide allowed identification and assignment of the signals due to NH and OH protons. The derived structure, 3‐((1H‐indol‐3‐yl)methyl)‐3,3a,6‐trihydroxytetrahydrofuro[3,2‐b]furan‐2(5H)‐one, agrees with the structure suggested for ascorbigen A in 1966. The density functional theory (DFT) calculations showed that among 16 possible stereoisomers, only two complied with the almost zero value of the measured 3J(H6–H6a). Of the two stereoisomers, 3S,3aS,6S,6aR and 3R,3aR,6R,6aS, the latter was excluded on synthetic grounds. The nuclear Overhauser effect measurements unveiled close proximity between H2′ proton of the indole and the H6a proton of the tetrahydrofuro[3,2‐b]furan part. Detailed structural interpretation of the measured NMR parameters by means of DFT NMR was hampered by rotational flexibility of the indole and tetrahydrofuro[3,2‐b]furan parts and inadequacy of Polarizable Continuum Model (PCM) solvent model.n

Název v anglickém jazyce

Ascorbigen A—NMR identification

Popis výsledku anglicky

The connectivities of all atoms in ascorbigen A, an important metabolite, were determined unambiguously for the first time. The connectivity between carbon atoms was established by 2D INADEQUATE, and one‐bond 13C–13C coupling constants were determined for all pairs of directly connected carbon atoms except for two strongly coupled carbon pairs. The 13C–13C coupling in one of the pairs was proved by a modification of standard INADEQUATE, however, the signals from the other pair were too weak to be observed. The connectivity within the two strongly coupled C–C pairs was confirmed by a combination of COSY and gHSQC, the latter experiment also identified all C–H bonds. The proton nuclear magnetic resonance (1H NMR) spectra in dry dimethyl sulfoxide allowed identification and assignment of the signals due to NH and OH protons. The derived structure, 3‐((1H‐indol‐3‐yl)methyl)‐3,3a,6‐trihydroxytetrahydrofuro[3,2‐b]furan‐2(5H)‐one, agrees with the structure suggested for ascorbigen A in 1966. The density functional theory (DFT) calculations showed that among 16 possible stereoisomers, only two complied with the almost zero value of the measured 3J(H6–H6a). Of the two stereoisomers, 3S,3aS,6S,6aR and 3R,3aR,6R,6aS, the latter was excluded on synthetic grounds. The nuclear Overhauser effect measurements unveiled close proximity between H2′ proton of the indole and the H6a proton of the tetrahydrofuro[3,2‐b]furan part. Detailed structural interpretation of the measured NMR parameters by means of DFT NMR was hampered by rotational flexibility of the indole and tetrahydrofuro[3,2‐b]furan parts and inadequacy of Polarizable Continuum Model (PCM) solvent model.n

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Magnetic Resonance in Chemistry

ISSN

0749-1581

e-ISSN

—

Svazek periodika

57

Číslo periodika v rámci svazku

12

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

13

Strana od-do

1084-1096

Kód UT WoS článku

000473987100001

EID výsledku v databázi Scopus

2-s2.0-85068378971