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.

Why are grape/fresh wine anthocyanins so simple and why is it that red wine color lasts so long?

Vitis vinifera red berries are characterized by anthocyanins whose chemical structures are among the simplest encountered in higher plants. On the contrary, many plants, including orchids, petunias, red cabbage, elderberries, potatoes for instance, have developed very complicated anthocyanins featuring side-chains at the available positions of the aglycone skeleton. Such pigments were shown to possess bio-physico-chemical properties not to be seen with the grape common anthocyanins.

Analysis and biological activities of anthocyanins.

Anthocyanins are naturally occurring compounds that impart color to fruits, vegetables, and plants. They are probably the most important group of visible plant pigments besides chlorophyll. Apart from imparting color to plants, anthocyanins also have an array of health-promoting benefits, as they can protect against a variety of oxidants through a various number of mechanisms.

Resveratrol analog (Z)-3,5,4'-trimethoxystilbene is a potent anti-mitotic drug inhibiting tubulin polymerization.

Resveratrol (3,5,4'-trihydroxystilbene) a natural polyphenol present in medicinal plants, grapes and wines, has potent chemopreventive properties on intestinal carcinogenesis. A methylated derivative (Z-3,5,4'-trimethoxystilbene: R3) was synthesized. R3 at 0.

Two diacylated malvidin glycosides from Petunia hybrida flowers.

Two novel diacylated and two known anthocyanins were isolated from violet flowers of Petunia hybrida cv Festival. The new anthocyanins are malvidin 3-O-(6-O-(4-O-(4-O-(6-O-feruloyl-beta-D-glucopyranosyl)-E-p-coumaroyl)-alpha-rhamnosyl)-beta-D-glucopyranoside)-5-beta-D-glucopyranoside and malvidin 3-O-(6-O-(4-O-(4-O-(6-O-E-p-coumaroyl-beta-D-glucopyranosyl)-E-p-coumaroyl)-alpha-rhamnosyl)-beta-D-glucopyranoside)-5-beta-D-glucopyranoside. The two known pigments are the 3-caffeoylglucosyl-p-coumaroylrutinoside-5-glucosides of malvidin and petunidin.

Influence of trans-cis isomerisation of coumaric acid substituents on colour variance and stabilisation in anthocyanins.

The recently isolated pigments from Petunia integrifolia and Triteleia bridgesii present a distinct feature that sheds new light on the understanding of intramolecular copigmentation of anthocyanins. These are among the infrequent anthocyanins that naturally present a coumaric acid substituent in both cis and trans forms. As a consequence, the two isomers demonstrate substantial variations of their thermodynamic and kinetic constants and also colour properties.

Polyphenols produced during red wine ageing.

Over the past few years, it has been accepted that a moderate red wine consumption is a factor beneficial to human health. Indeed, people of France and Italy, the two major wine-producing European countries, eat a lot of fatty foods but suffer less from fatal heart strokes than people in North-America or in the northern regions of Europe, where wine is not consumed on a regular basis. For a time, ethanol was thought to be the "good" chemical species hiding behind what is known as the "French paradox".

New aspects of anthocyanin complexation. Intramolecular copigmentation as a means for colour loss?

Two series of structurally related anthocyanins, extracted from the blue flowers of Evolvulus pilosus cv. Blue Daze and from the blue-purple flowers of Eichhornia crassipes, exhibit remarkable colour stabilities in aqueous solution at mildly acidic pH values. All the pigments possess the same chromophore (delphinidin), but a different pattern of glycosylation and acylation.

The effect of liver denervation on hepatic hemodynamics during hypovolemic shock in swine.

This study tested the hypothesis that the denervated liver is more susceptible to hypovolemic shock than the normal liver. Fourteen swine, seven nondenervated and seven after liver denervation, were studied during hypovolemic shock to 50% of baseline blood pressure. Hepatic artery and portal vein flows were measured using transonic flow probes, and cardiac output and central venous pressure were measured using Swan-Ganz catheters.

An in vivo examination of rat brain during sepsis with 31P-NMR spectroscopy.

Neurological symptoms including lethargy, obtundation, and confusion are early and common findings in patients with sepsis. The etiology of the mental status changes that occur during severe infection is not known. We investigated the effects of sepsis on the levels of high-energy phosphates to determine whether decreased energy metabolism was a factor in the depressed neurological state.

Water vapor pressure calculation.

Accurate calculation of water vapor pressure for systems saturated with water vapor can be performed using the Goff-Gratch equation. A form of the equation that can be adapted for computer programming and for use in electronic databases is provided.

Splenic sequestration and ineffective erythropoiesis in hemoglobin E-beta-thalassemia disease.

A 13-year-old Thai female with hemoglobin E-beta-thalassemia was evaluated for anemia and splenomegaly. Globin chain synthesis in a whole cell system revealed an absence of betaA chains and excessive alpha chains. The alpha/betaE + gamma ratio was 1.

RBC transfusions in paroxysmal nocturnal hemoglobinuria.

Frozen-thawed, deglycerolized RBCs can be substituted for saline-washed RBCs for transfusion of patients with paroxysmal nocturnal hemoglobinuria (PNH). The effect of transfusion is to decrease bone marrow production of RBCS, which results in a decreased percentage of complement-sensitive erythrocytes. In the presence of small numbers of complement-sensitive erythrocytes, major vascular surgery can be performed without hemolytic problems.

Endogenous production of carbon monoxide as measured simultaneously in blood and gas phase.

Endogenous carbon monoxide (CO) production rates and total body haemoglobin content were determined simultaneously in blood and gas phase in 15 individuals. At 24% oxygen (O2) concentration in the closed rebreathing system, a correlation was obtained which revealed that a 1 mumole rise in CO in the gas phase of the system was the result of 48.94 +/- 5.

Effect of blood in the gut on measurements of endogenous carbon monoxide production.

Changes induced in measurements of endogenous carbon monoxide (CO) production by blood in the lumen of the gut were studied in five normal volunteers. The study was undertaken because exogenous heme is absorbed by intestinal mucosal cells where the porphyrin ring is split with the release of CO that could contribute to blood CO levels and lead to a fallacious diagnosis of hemolytic disease. Volunteers who consumed 200 ml of their own blood doubled their endogenous production of CO (0.