On the Cholesterol Raising Effect of Coffee Diterpenes Cafestol and 16--Methylcafestol: Interaction with Farnesoid X Receptor.

The diterpene cafestol represents the most potent cholesterol-elevating compound known in the human diet, being responsible for more than 80% of the effect of coffee on serum lipids, with a mechanism still not fully clarified. In the present study, the interaction of cafestol and 16--methylcafestol with the stabilized ligand-binding domain (LBD) of the Farnesoid X Receptor was evaluated by fluorescence and circular dichroism. Fluorescence quenching was observed with both cafestol and 16--methylcafestol due to an interaction occurring in the close environment of the tryptophan W454 residue of the protein, as confirmed by docking and molecular dynamics.

Validation of a rapid ultra-high-performance liquid chromatography-tandem mass spectrometry method for quantification of chlorogenic acids in roasted coffee.

Chlorogenic acids (CGAs) are a large class of esters formed between quinic acid and hydroxycinnamic acids. They are present in coffee as a complex mixture of positional and geometric isomers, where caffeoylquinic acids (CQAs) are the most abundant, followed by dicaffeoylquinic acids (diCQAs), feruloylquinic acids (FQAs), and p-coumaroylquinic acids (p-CoQAs). The aim of this work is to develop a new reliable and fast liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous identification and quantification of total amount of 11 CGAs in roasted coffee.

16-O-Methylated diterpenes in green Coffea arabica: ultra-high-performance liquid chromatography-tandem mass spectrometry method optimization and validation.

Coffee diterpenes are the main constituents of the coffee oil unsaponifiable fraction. The three most important diterpenes are cafestol, kahweol, and 16-O-methylcafestol (16-OMC), and they are produced, except for cafestol, only by plants of the Coffea genus. Recently, in addition to these three major diterpenes, another 16-O-methylated diterpene (16-O-methylkahweol: 16-OMK) has been identified and quantified, for the first time, in Robusta coffee.

Limited genotypic and geographic variability of 16-O-methylated diterpene content in Coffea arabica green beans.

The acknowledged marker of Robusta coffee, 16-O-methylcafestol (16-OMC), can be quantified by NMR as a mixture with 16-O-methylkahweol (16-OMK), which accounts for approximately 10% of the mixture. In the present study, we detected and quantified 16-O-methylated diterpenes (16-OMD) in 248 samples of green Coffea arabica beans by NMR. We did not observe any differences between genotypes introgressed by chromosomal fragments of Robusta and non-introgressed genotypes.

Interaction of the Coffee Diterpenes Cafestol and 16--Methyl-Cafestol Palmitates with Serum Albumins.

The main coffee diterpenes cafestol, kahweol, and 16--methylcafestol, present in the bean lipid fraction, are mostly esterified with fatty acids. They are believed to induce dyslipidaemia and hypercholesterolemia when taken with certain types of coffee brews. The study of their binding to serum albumins could help explain their interactions with biologically active xenobiotics.

Interaction of coffee compounds with serum albumins. Part II: Diterpenes.

Cafestol and 16-O-methylcafestol are diterpenes present in coffee, but whilst cafestol is found in both Coffea canephora and Coffea arabica, 16-O-methylcafestol (16-OMC) was reported to be specific of only C. canephora. The interactions of such compounds, with serum albumins, have been studied.