Revisiting the structure of Heliannuol L: A computational approach.

Autor: Martorano LH; Department of Organic Chemistry, Chemistry Institute, Fluminense Federal University (UFF), Niterói, Brazil., Brito JT; Department of Organic Chemistry, Chemistry Institute, Fluminense Federal University (UFF), Niterói, Brazil., de Albuquerque ACF; Department of Organic Chemistry, Chemistry Institute, Fluminense Federal University (UFF), Niterói, Brazil., Ribeiro CMR; Department of Organic Chemistry, Chemistry Institute, Fluminense Federal University (UFF), Niterói, Brazil., Fiorot RG; Department of Organic Chemistry, Chemistry Institute, Fluminense Federal University (UFF), Niterói, Brazil., Carneiro JWM; Department of Inorganic Chemistry, Chemistry Institute, Fluminense Federal University (UFF), Niterói, Brazil., Costa FLP; Chemistry Institute, Federal University of Jataí (UFJ), Jataí, Brazil., Valverde AL; Department of Organic Chemistry, Chemistry Institute, Fluminense Federal University (UFF), Niterói, Brazil., Dos Santos Junior FM; Department of Organic Chemistry, Chemistry Institute, Fluminense Federal University (UFF), Niterói, Brazil.
Jazyk: angličtina
Zdroj: Magnetic resonance in chemistry : MRC [Magn Reson Chem] 2022 Apr; Vol. 60 (4), pp. 434-441. Date of Electronic Publication: 2021 Nov 13.
DOI: 10.1002/mrc.5230
Abstrakt: Recently, structural elucidation of natural products has undergone a revolution. The combined use of different modern spectroscopic methods has allowed obtaining a complete structural assignment of natural products using small amounts of sample. However, despite the extraordinary ongoing advances in spectroscopy, the mischaracterization of natural products has been and remains a recurrent problem, especially when the substance presents several stereogenic centers. The misinterpretation of nuclear magnetic resonance (NMR) data has resulted in frequent reports addressing structural reassignment. In this context, a great effort has been devoted to developing quantum chemical calculations that simulate NMR parameters accurately, allowing to achieve a more precise spectral interpretation. In this work, we employed a protocol for theoretical calculations of 1 H NMR chemical shifts and coupling constants using density functional theory (DFT), followed by the application of the DP4+ method to revisit the structure of Heliannuol L, a member of the Heliannuol class, isolated from Helianthus annuus. Our results indicate that the originally proposed structure of Heliannuol L needs a stereochemical reassignment, placing the hydroxyl bonded to C10 in the opposite side of the methyl and hydroxyl groups bonded to C7 and C8, respectively.
(© 2021 John Wiley & Sons, Ltd.)
Databáze: MEDLINE
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