A combined experimental and computational chiroptical approach to establish the biosynthesis and absolute configuration of licochalcone L.

Autor: Pandey P; National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677-1848, United States., Neal WM; Department of BioMolecular Sciences, Division of Pharmacognosy, School of Pharmacy, University of Mississippi, University, MS 38677-1848, United States., Zulfiqar F; National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677-1848, United States., Ali Z; National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677-1848, United States., Khan IA; National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677-1848, United States; Department of BioMolecular Sciences, Division of Pharmacognosy, School of Pharmacy, University of Mississippi, University, MS 38677-1848, United States. Electronic address: ikhan@olemiss.edu., Ferreira D; National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677-1848, United States; Department of BioMolecular Sciences, Division of Pharmacognosy, School of Pharmacy, University of Mississippi, University, MS 38677-1848, United States., Chittiboyina AG; National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677-1848, United States. Electronic address: amar@olemiss.edu.
Jazyk: angličtina
Zdroj: Phytochemistry [Phytochemistry] 2023 Aug; Vol. 212, pp. 113732. Date of Electronic Publication: 2023 May 26.
DOI: 10.1016/j.phytochem.2023.113732
Abstrakt: Often, chiral natural products exist as single stereoisomers; however, simultaneous occurrences of both enantiomers can exist in nature, resulting in scalemic or racemic mixtures. Ascertaining theabsolute configuration (AC) of natural products is pivotal for attributing their specific biological signature. Specific rotation data commonly characterize chiral non-racemic natural products; however, measurement conditions, viz., solvent and concentration, can influence the sign of specific rotation values, especially when characterizing natural products possessing small values. For example, licochalcone L, a minor constituent of Glycyrrhiza inflata, was reported with a specific rotation of [α] D 22 = +13 (c 0.1, CHCl 3 ); however, not establishing the AC and the reported zero specific rotation for an identical compound, licochalcone AF1, resulted in debatable chirality and its biogenesis. In this study, a combined experimental and computational chiroptical approach involving specific rotation and electronic circular dichroism (ECD) data, supported by time-dependent density functional theory (TDDFT), were effectively utilized to establish the AC of licochalcone L as the (E, 2″S)-isomer. Establishing the 2″S absolute configuration permitted the conception of a reasonable biosynthetic pathway involving intramolecular '5-exo-tet' ring opening of a chiral oxirane to form chiral licochalcone L in G. inflata.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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