TRPA1 Modulating C14 Polyacetylenes from the Iranian Endemic Plant Echinophora platyloba

Abstract

Phytochemical investigation of the apolar extract obtained from aerial parts of the Iranian endemic plant Echinophora platyloba DC (Apiaceae) resulted in the characterization of the polyacetylene fraction of this plant. This resulted to be composed of the known echinophorins A and B, embedding the very rare α-pyrone terminal, and of the new echinophorin D (3), including also three conjugated triple bonds. The chemical structures of these compounds were secured by detailed inspection of MS and 1D/2D NMR spectra. The isolated polyacteylenes were evaluated for their modulation of six thermo-TRP channels and they revealed a selective activity on TRPA1, an ion channel involved in the mediation of neuropathic and inflammatory pain. This is the first report on the activity of plant polyacetylenes on transient receptor potential (TRP) channels.

Mammalian Transient Receptor Potential TRPA1 Channels: From Structure to Disease

“…Other reported TRPA1 agonists of natural origin are leucettamols, bifunctionalized sphingoid-like compounds from a marine sponge Leucetta sp (157), C 14 polyacetylenes from the plant Echinophora platyloba (Apiaceae) (158), and compounds from the Himalayan ritual medicinal plant Waldheimia glabra (277).…”

Genus Echinophora—Biological Activity, Chemical Composition, and Future Perspectives

“…Phytochemical studies regarding the composition of Echinophora extracts are limited. In general, the main compounds identified in extracts of this botanical genus are polyphenolic compounds, including phenolic acids, flavonoids, and coumarins, as well as polyacetylenes, fatty acids, and terpenoids, namely phytosterols [ 2 , 11 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. An overview of the secondary metabolites identified and isolated from extracts of Echinophora species is depicted in Table 1 .…”

“…Characteristic bioactive chemical compounds for the Apiaceae family are polyacetylenes, mainly represented by the falcarinol-type C 17 -polyacetylenes [ 27 ]. The archetypal C 17 -polyacetylene falcarinol is an aliphatic alcohol biosynthesized from fatty acids, the structure of which contains two triple bonds and two double bonds ( Figure 2 A) [ 2 , 27 ]. A less common class of polyacetylenes, the C 14 -polyacetylenes, have been described in extracts of different plant species, including Codonopsis pilosula [ 28 ], Coreopsis tinctoria [ 29 , 30 ], and species from the genus Lobelia and the genus Siphocampylus [ 31 ].…”

“…The name Echinophora originates from ancient Greek and is composed of the words echino (spine) and phora (leaf), which describe the spiny leaves of the species within the genus [ 2 ]. The genus is distributed in regions of the Mediterranean and the Balkan Peninsula, Anatolia, eastward to Iran and Afghanistan [ 3 ].…”

“…It was found that these compounds demonstrate significant selectivity toward the transient receptor potential channels of ankyrin type-1 (TRPA1). Echinophorins are considered to have a promising potential in the management of pain and inflammation [ 2 ].…”