Analytik von Carbons�urehydroxytryptamiden in Kaffee

Two New βN-Alkanoyl-5-Hydroxytryptamides with Relevant Antinociceptive Activity

In this work, we describe a new route for the synthesis and the antinociceptive effects of two new ^βN-alkanoyl-5-hydroxytryptamides (named C_20:0-5HT and C_22:0-5HT). The antinociceptive activities were evaluated using well-known models of thermal-induced (reaction to a heated plate, the hot plate model) or chemical-induced (licking response to paw injection of formalin, capsaicin, or glutamate) nociception. The mechanism of action for C_20:0-5HT and C_22:0-5HT was evaluated using naloxone (opioid receptor antagonist, 1 mg/kg), atropine (muscarinic receptor antagonist, 1 mg/kg), AM251 (cannabinoid CB1 receptor antagonist, 1 mg/kg), or ondansetron (5-HT3 serotoninergic receptor antagonist, 0.5 mg/kg) 30 min prior to C_20:0-5HT or C_22:0-5HT. The substances both presented significant effects by reducing licking behavior induced by formalin, capsaicin, and glutamate and increasing the latency time in the hot plate model. Opioidergic, muscarinic, cannabinoid, and serotoninergic pathways seem to be involved in the antinociceptive activity since their antagonists reversed the observed effect. Opioid receptors are partially involved due to tolerant mice demonstrating less antinociception when treated with both compounds. Our data showed a quicker and simpler route for the synthesis of the new ^βN-alkanoyl-5-hydroxytryptamides. Both compounds demonstrated significant antinociceptive effects. These new compounds could be used as a scaffold for the synthesis of analogues with promising antinociceptive effects.

Quantitation of (beta)N-Alkanoyl-5-hydroxytryptamides in coffee by means of LC-MS/MS-SIDA and assessment of their gastric acid secretion potential using the HGT-1 cell assay

A straightforward stable isotope dilution analysis (SIDA) for the reliable quantitative determination of (beta)N-C(18:0)- to (beta)N-C(24:0)-alkanoyl-5-hydroxytryptamides (C5HTs) in coffee powder and beverages by means of LC-MS/MS was developed. The developed SIDA showing accuracy values of 92.6-107% and precision between 0.5 and 7% relative standard deviation for the individual derivatives allowed the sensitive and selective quantification of the target compounds in coffee beverages. Depending on the type of coffee, quantitation revealed C5HT levels between 65 and 144 microg/L in filtered coffee and up to 3500 microg/L in a French press beverage, thus indicating that about 0.3 or 7.2% of the C5HTs were extracted from the coffee powder into the beverage when using the cellulose filter method or the French press, respectively. To estimate the potential contribution of the C5HTs to the phenomenon of stomach irritation after ingestion of coffee brew, in vitro cell studies were performed with pure individual 5-hydroxytryptamides and a mixture of the predominating derivatives in ratios matching those found in coffee. All substances tested induced a decrease in the intracellular proton index (IPX) coined as an indicator of stomach acid secretion. While the biomimetic C5HT mixture was highest in its inducing effect, the individual stearic acid, oleic acid, and linoleic acid 5-hydroxytryptamide did not differ significantly from each other, but showed a less pronounced effect compared to arachinic acid 5-hydroxytryptamide. In conclusion, not the grade of saturation seems to determine the C5HT's mode of action in driving the stomach acid secretion, rather than the fatty acid chain length.

The lipid fraction of the coffee bean

The lipid fraction of coffee is composed mainly of triacylglycerols, sterols and tocopherols, the typical components found in all common edible vegetable oils. Additionally, the so-called coffee oil contains diterpenes of the kaurene family in proportions of up to 20 % of the total lipids. Diterpenes are of interest because of their analytical and physiological effects. The composition of the main lipid components of the two most important coffee species, Coffea arabica and Coffea canphora var. Robusta is presented. In addition, the influences of typical processes like roasting and steaming on selected lipid components as well as the effects of the storage of green coffee beans under different conditions will be described. Furthermore, new findings regarding the 5-hydroxytryptamides, the main parts of the coffee wax located on the outer layer of the bean and the recently identified components coffeadiol and arabiol I will also be discussed.