Synthesis and Biological Evaluation of Falcarinol-Type Analogues as Potential Calcium Channel Blockers

J Nat Prod. 2021 Aug 27;84(8):2138-2148. doi: 10.1021/acs.jnatprod.1c00136. Epub 2021 Jul 28.

Abstract

A series of enantiomers of falcarinol analogues (2) were synthesized using a chiral 1,1'-binaphth-2-ol (BINOL)-based catalytic system. The neuroprotective effects of falcarinol (1a) and its analogues (2) on PC12 cells injured by sodium azide (NaN3) were investigated. The structure-function relationships and possible mechanism were studied. Pretreatment of PC12 cells with falcarinol analogues (R)-2d and (R)-2i for 1 h following addition of NaN3 and culture in a CO2 incubator for 24 h resulted in significant elevation of cell viability, as determined by a CCK-8 assay and Hoechst staining, with reduction of LDH release and MDA content, increase of SOD activity, and decrease of ROS stress, when compared with the activity of natural falcarinol (1a). These observations indicated that the falcarinol analogues (R)-2d and (R)-2i can protect PC12 cells against NaN3-induced apoptosis via increasing resistance to oxidative stress. For the first time, falcarinol (1a) and its analogue (R)-2i were found to have potential L-type calcium channel-blocking activity, as recorded using a manual patch clamp technique on HEK-293 cells stably expressing hCav1.2 (α1C/β2a/α2δ1). These findings suggest that the mechanism of the L-type calcium channel-blocking activity of falcarinol (1a) and its analogue (R)-2i might be involved in neuroprotection by falcarinol-type analogues by inhibiting calcium overload in the upstream of the signaling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium Channel Blockers / chemical synthesis
  • Calcium Channel Blockers / pharmacology*
  • Cell Survival / drug effects
  • Diynes / chemical synthesis
  • Diynes / pharmacology*
  • Fatty Alcohols / chemical synthesis
  • Fatty Alcohols / pharmacology*
  • HEK293 Cells
  • Humans
  • Molecular Structure
  • Neuroprotective Agents / chemical synthesis
  • Neuroprotective Agents / pharmacology*
  • Oxidative Stress / drug effects
  • PC12 Cells
  • Rats
  • Signal Transduction / drug effects

Substances

  • Calcium Channel Blockers
  • Diynes
  • Fatty Alcohols
  • Neuroprotective Agents
  • falcarinol