Retrochalcone derivatives are positive allosteric modulators at synaptic and extrasynaptic GABA(A) receptors in vitro.

Background And Purpose: Flavonoids, important plant pigments, have been shown to allosterically modulate brain GABA(A) receptors (GABA(A)Rs). We previously reported that trans-6,4'-dimethoxyretrochalcone (Rc-OMe), a hydrolytic derivative of the corresponding flavylium salt, displayed nanomolar affinity for the benzodiazepine binding site of GABA(A)Rs. Here, we evaluate the functional modulations of Rc-OMe, along with two other synthetic derivatives trans-6-bromo-4'-methoxyretrochalcone (Rc-Br) and 4,3'-dimethoxychalcone (Ch-OMe) on GABA(A)Rs.

Flavylium salts as in vitro precursors of potent ligands to brain GABA-A receptors.

The synthesis of a series of derivatized flavylium cations was undertaken and the affinity to the benzodiazepine binding site of the GABA-A receptor evaluated. The observed high affinity for some derivatives (sub-muM range) was explained by an in vitro transformation of the flavylium cations into the corresponding trans-retrochalcones, components which are proposed to be the active species in this series.

Croton lobatus, an African medicinal plant: spectroscopic and chemical elucidation of its many constituents.

The chemical constituents of the African medicinal plant Croton lobatus were elucidated and characterised using 1D and 2D-NMR analysis and the application of the technique of High Resolution Electron Ionization Mass Spectrometry (HREIMS) and High Resolution Mass Spectrometry (HRMS). The novel triglyceride lobaceride or 3-((6Z,9Z)dodeca-6,9-dienoyloxy)-2-octanoyloxypropyl (6Z,9Z)dodeca-6,9-dienoate, along with ten compounds were isolated from the stems and leaves of Croton lobatus.

Anti-mitotic properties of resveratrol analog (Z)-3,5,4'-trimethoxystilbene.

(Z)-3,5,4'-Trimethoxystilbene is a natural polyphenol present in five different plants, Virola cuspidata, Virola elongata, Centipeda minima, Schoenus nigricans and Rheum undulatum. This molecule was prepared in a three-step sequence in good overall yield. The isomerisation from the (E)- to (Z)-isomer is performed using UV irradiation.

Concise synthesis of dihydrochalcones via palladium-catalyzed coupling of aryl halides and 1-aryl-2-propen-1-ols.

An expedient route to substituted dihydrochalcones is reported. The key step is a palladium-assisted arylation of 1-aryl-2-propen-1-ols. This two-step/one-purification process allows the synthesis of a wide range of compounds with original substitution patterns, including polyphenolic derivatives.