Hyperelatolides A-D, Antineuroinflammatory Constituents with Unusual Carbon Skeletons from Hypericum elatoides

J Nat Prod. 2023 Aug 25;86(8):1910-1918. doi: 10.1021/acs.jnatprod.3c00226. Epub 2023 Aug 2.

Abstract

Four new δ- and γ-lactone derivatives, hyperelatolides A-D (1-4, respectively), were discovered from the aerial portions of Hypericum elatoides R. Keller. Their structures were elucidated by analysis of NMR spectra, HRESIMS, quantum chemical calculations of NMR and ECD spectra, and X-ray crystallographic data. Hyperelatolides A (1) and B (2) represent the first examples of δ-lactone derivatives characterized by a (Z)-(5,5-dimethyl-2-(2-oxopropyl)cyclohexylidene)methyl moiety and a benzoyloxy group attached to the β- and γ-positions of the δ-lactone core, respectively, while hyperelatolides C (3) and D (4) are unprecedented γ-lactone derivatives featuring substituents similar to those of 1 and 2. All compounds were tested for their inhibitory effects on NO production in LPS-activated BV-2 cells. Lactones 1 and 2 exhibited considerable antineuroinflammatory activity, with IC50 values of 5.74 ± 0.27 and 7.35 ± 0.26 μM, respectively. Moreover, the mechanistic study revealed that lactone 1 significantly suppressed nuclear factor kappa B signaling and downregulated the expression of inducible nitric oxide synthase and cyclooxygenase-2 in LPS-induced cells, which may contribute to its antineuroinflammatory activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Hypericum* / chemistry
  • Lactones / chemistry
  • Lactones / pharmacology
  • Lipopolysaccharides / pharmacology
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Nitric Oxide
  • Signal Transduction

Substances

  • Lipopolysaccharides
  • Lactones
  • Nitric Oxide