Quality Assessment of Ground Coffee Samples from Greek Market Using Various Instrumental Analytical Methods, In Silico Studies and Chemometrics.

Coffee is one of the most widely consumed beverages worldwide due to its sensory and potential health-related properties. In the present comparative study, a preparation known as Greek or Turkish coffee, made with different types/varieties of coffee, has been investigated for its physicochemical attributes (i.e., color), antioxidant/antiradical properties, phytochemical profile, and potential biological activities by combining high-throughput analytical techniques, such as infrared spectroscopy (ATR-FTIR), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and in silico methodologies. The results of the current study revealed that roasting degree emerged as the most critical factor affecting these parameters. In particular, the L* color parameter and total phenolic content were higher in light-roasted coffees, while decaffeinated coffees contained more phenolics. The ATR-FTIR pinpointed caffeine, chlorogenic acid, diterpenes, and quinic esters as characteristic compounds in the studied coffees, while the LC-MS/MS analysis elucidated various tentative phytochemicals (i.e., phenolic acids, diterpenes, hydroxycinnamate, and fatty acids derivatives). Among them, chlorogenic and coumaric acids showed promising activity against human acetylcholinesterase and alpha-glucosidase enzymes based on molecular docking studies. Therefore, the outcomes of the current study provide a comprehensive overview of this kind of coffee preparation in terms of color parameters, antioxidant, antiradical and phytochemical profiling, as well as its putative bioactivity.

Towards the Optimization of Microwave-Assisted Extraction and the Assessment of Chemical Profile, Antioxidant and Antimicrobial Activity of Wine Lees Extracts.

Wine lees, a sub-exploited byproduct of vinification, is considered a rich source of bioactive compounds, such as (poly)phenols, anthocyanins and tannins. Thus, the effective and rapid recovery of these biomolecules and the assessment of the bioactive properties of wine lees extracts is of utmost importance. Towards this direction, microwave-assisted extraction (MAE) factors (i.e., extraction time, microwave power and solvent/material ratio) were optimized using experimental design models in order to maximize the (poly)phenolic yield of the extracts. After optimizing the MAE process, the total phenolic content (TPC) as well as the antiradical, antioxidant and antimicrobial activity of the extracts were evaluated. Furthermore, Fourier transform infrared spectroscopy (FTIR) was employed to investigate the chemical profile of wine lees extracts. Red varieties exhibited higher biological activity than white varieties. The geographical origin and fermentation stage were also considered as critical factors. The white variety Moschofilero presented the highest antioxidant, antiradical and antimicrobial activity, while Merlot and Agiorgitiko samples showed noteworthy activities among red varieties. Moreover, IR spectra confirmed the presence of sugars, amino acids, organic acids and aromatic compounds. Thus, an efficient, rapid and eco-friendly process was proposed for further valorization of wine lees extracts.

Quality Assessment of Pork and Turkey Hams Using FT-IR Spectroscopy, Colorimetric, and Image Analysis.

The implementation of fast and nondestructive methods in meat products and colds cuts have become increasingly important to evaluate their quality in relation to different factors such as origin, type of processing, freshness, adulteration, and authenticity. In this study, Fourier Transform Infrared Spectroscopy (FT-IR), colorimetric, and image-analysis methods were implemented to characterize and classify ham cold cuts in terms of meat type, processing, and shelf life during refrigerated storage. Two types of commercial hams (made from pork and turkey) and three types of processing (boiled, smoked, and roasted) were selected. By using the most appropriate color parameters, a*, h, and C*, as well as the textural features' angular second moment, long-running emphasis, and standard deviation of image intensity from the hams' images, high-classification values for the different ham samples were achieved. The FT-IR analysis revealed the presence of absorbance bands of proteins, triglycerides, fatty acids, and carbohydrates with different intensities according to meat type and processing. Refrigeration storage caused significant alterations of color parameters and a partial degradation of triglycerides and proteins. Moreover, the image-analysis findings indicated that storage period caused significant degradation of ham images relating to local linearity, and structural and textural continuum.

A computational study on cannabinoid receptors and potent bioactive cannabinoid ligands: homology modeling, docking, de novo drug design and molecular dynamics analysis.

When X-ray structure of a ligand-bound receptor is not available, homology models of the protein of interest can be used to obtain the ligand-binding cavities. The steroelectronic properties of these cavities are directly related to the performed molecular model coordinates. Thus, the use of different template structures for homology may result in variation of ligand-binding modes. We have recently reported the MD simulations of a potent CB ligand at bovine rhodopsin-based CB1 and CB2 receptors (Durdagi et al., Bioorg Med Chem 16:7377-7387, 2008). In this present study, a homology modeling study based on the beta2-adrenergic receptor for both CB1 and CB2 receptors was performed, and the results were compared with rhodopsin-based models. In addition, the role of membrane bilayers to the adopted conformations of potent AMG3 CB ligand has been analyzed for receptor-free and membrane-associated receptor systems. The performed MD trajectory analysis results have shown that gauche conformations at the terminal segment of the alkyl side chain of AMG3 are not favored in solution. Different adopting dihedral angles defined between aromatic and dithiolane rings at the active sites of the CB1 and CB2 receptors, which are adapted lead to different alkyl side chain orientations and thus, may give clues to the medicinal chemists to synthesize more selective CB ligands. The binding sites of receptors derived by rhodopsin-based models have been regenerated using the beta2-adrenergic based template receptors. The re-obtained models confirmed the ligand-binding pockets that were derived based on rhodopsin.

Structure elucidation and conformational study of V8: a novel synthetic non peptide AT(1) antagonist.

AT(1) antagonists constitute the most recent class of antihypertensive drugs which act through the Renin Angiotensin System (RAS). In an effort to comprehend their stereoelectronic features, a study was initiated to compare the conformational properties of drugs already marketed for the treatment of hypertension with synthetic ones, possessing common structural characteristics. In this study, the synthetic AT(1) antagonist V8 is structurally elucidated and its conformational properties are studied through a combination of NMR spectroscopy and computational analysis. Its conformational properties are compared with those of the structurally similar prototype AT(1) antagonist losartan.

Structure elucidation and conformational properties of eprosartan, a non peptide angiotensin II AT1 antagonist.

A novel approach to treat hypertension is to interfere with the Renin-Angiotensin system (RAS) by blocking the binding of vasoconstrictive hormone Angiotensin II to the AT(1) receptor site. This approach led to the beneficial drug losartan (COZAAR) and other similar in structure to the antihypertensive drugs (sartans). In an effort to compare the stereoelectronic features of pharmacophoric segments of the different sartans, a research activity was initiated in our laboratory related to the conformational properties of these drugs. In a previous study, the structural features which determine the pharmacophoric segments of losartan were examined. In this study, the conformational properties of eprosartan (TEVETEN), a drug with fewer side effects, were examined. In addition, the superimposition ability of losartan and eprosartan with the peptide antagonist sarmesin was studied.