Pauciflorins A-E, Unexpected Chromone-Monoterpene-Derived Meroterpenoids from Centrapalus pauciflorus

J Nat Prod. 2023 Apr 28;86(4):891-896. doi: 10.1021/acs.jnatprod.2c01132. Epub 2023 Mar 18.

Abstract

Five unusual meroterpenoids based on new carbon skeletons, pauciflorins A-E (1-5), were isolated by multistep chromatographic separations of a methanol extract of the aerial parts of Centrapalus pauciflorus. Compounds 1-3 are derived by the connection of a 2-nor-chromone and a monoterpene unit, whereas 4 and 5 are dihydrochromone-monoterpene adducts with a rarely occurring orthoester functionality. The structures were solved using 1D and 2D NMR, HRESIMS, and single-crystal X-ray diffraction. Pauciflorins A-E were evaluated for antiproliferative activity against human gynecological cancer cell lines, but were inactive (IC50 < 10 μM) in each case.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromones* / pharmacology
  • Crystallography, X-Ray
  • Humans
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Monoterpenes*

Substances

  • Monoterpenes
  • Chromones