Omanische Heilpflanze im Fokus der Phytochemie IPB-Wissenschaftler und Partner aus Dhofar haben jüngst die omanische Heilpflanze Terminalia dhofarica unter die phytochemische Lupe genommen. Die Pflanze ist reich an…
Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Hegazi, N. M.; Khattab, A. R.; Frolov, A.; Wessjohann, L. A.; Farag, M. A.;Authentication of saffron spice accessions from its common substitutes via a multiplex approach of UV/VIS fingerprints and UPLC/MS using molecular networking and chemometricsFood Chem.367130739(2022)DOI: 10.1016/j.foodchem.2021.130739
Saffron is a spice revered for its unique flavor and health attributes
often subjected to fraudulence. In this study, molecular networking as a
visualization tool for UPLC/MS dataset of saffron and its common
substitutes i.e. safflower and calendula (n = 21) was employed for determining genuineness of saffron and detecting its common substitutes i.e. safflower and calendula. Saffron was abundant in flavonol-O-glycosides
and crocetin esters versus richness of flavanones/chalcones glycosides
in safflower and cinnamates/terpenes in calendula. OPLS-DA identified
differences in UPLC/MS profiles of different saffron accessions where
oxo-hydroxy-undecenoic acid-O-hexoside was posed as saffron
authentication marker and aided in discrimination between Spanish
saffron of high quality from its inferior grade i.e. Iranian saffron along with crocetin di-O-gentiobiosyl ester and kaempferol-O-sophoroside. Kaempferol-O-neohesperidoside and N,N,N,-p-coumaroyl spermidine were characteristic safflower metabolites, whereas, calendulaglycoside C and di-O-caffeoyl
quinic acid were unique to calendula. UV/VIS fingerprint spectral
regions of picrocrocin (230–260 nm) and crocin derivatives (400–470 nm)
were posed as being discriminatory of saffron authenticity and
suggestive it can replace UPLC/MS in saffrom quality determination.
Publikation
Frolova, N.; Soboleva, A.; Nguyen, V. D.; Kim, A.; Ihling, C.; Eisenschmidt-Bönn, D.; Mamontova, T.; Herfurth, U. M.; Wessjohann, L. A.; Sinz, A.; Birkenmeyer, C.; Frolov, A.;Probing glycation potential of dietary sugars in human blood by anintegrated in vitro approachFood Chem.347128951(2021)DOI: 10.1016/j.foodchem.2020.128951
Glycation is referred to as the interaction of protein amino and guanidino groups with reducing sugars and carbonyl products of their degradation. Resulting advanced glycation end-products (AGEs) contribute to pathogenesis of diabetes mellitus and neurodegenerative disorders. Upon their intestinal absorption, dietary sugars and á-dicarbonyl compounds interact with blood proteins yielding AGEs. Although the differences in glycation potential of monosaccharides are well characterized, the underlying mechanisms are poorly understood. To address this question, D-glucose, D-fructose and L-ascorbic acid were incubated with human serum albumin (HSA). The sugars and á-dicarbonyl intermediates of their degradation were analyzed in parallel to protein glycation patterns (exemplified with hydroimidazolone modifications of arginine residues and products of their hydrolysis) by bottom-up proteomics and computational chemistry. Glycation of HSA with sugars revealed 9 glyoxal- and 14 methylglyoxal-derived modification sites. Their dynamics was sugar-specific and depended on concentrations of á-dicarbonyls, their formation kinetics, and presence of stabilizing residues in close proximity to the glycation sites.
Publikation
Farag, M. A.; El-Kersh, D. M.; Ehrlich, A.; Choucry, M. A.; El-Seedi, H.; Frolov, A.; Wessjohann, L. A.;Variation in Ceratonia siliqua pod metabolome in context of its different geographical origin, ripening stage and roasting processFood Chem.283675-687(2019)DOI: 10.1016/j.foodchem.2018.12.118
Carob is a legume tree of a considerable commercial importance for the flavor and sweet industry. In this context, it is cultivated mostly for its pods, which are known for their nutritive value and multiple health benefits. However, metabolite patterns, underlying these properties are still mostly uncharacterized. In this study, the role of geographical origin, ontogenetic changes and thermal processing on the Ceratonia siliqua pod metabolome was assessed by mass spectrometry (MS)-based metabolomics. Thereby, a total of 70 fruits primary metabolites, represented mainly by carbohydrates, organic and amino acids were detected. Analysis of secondary bioactive metabolites assessed by ultra-high-performance liquid chromatography-electrospray ionization high resolution mass spectrometry (UHPLC-ESI-HR-MS) revealed in total 83 signals. The major signals, most significantly contributing in discrimination of C. siliqua specimens were assigned to tannins and flavonoids. PCA models derived from either UHPLC-MS or GC-MS proved to be powerful tools for discrimination of C. siliqua specimens.
Publikation
Rasheed, D. M.; Porzel, A.; Frolov, A.; El Seedi, H. R.; Wessjohann, L. A.; Farag, M. A.;Comparative analysis of Hibiscus sabdariffa (roselle) hot and cold extracts in respect to their potential for α-glucosidase inhibitionFood Chem.250236-244(2018)DOI: 10.1016/j.foodchem.2018.01.020
Roselle (Hibiscus sabdariffa) is a functional food with potential health benefits, consumed either as hot or cold beverage. To ensure quality control of its various products, accurate measurement of active metabolites is warranted. Herein, we propose a combination of ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) and nuclear magnetic resonance (NMR) analytical platforms for the untargeted characterization of metabolites in two roselle cultivars, Aswan and Sudan-1. The analyses revealed 33 metabolites, including sugars, flavonoids, anthocyanins, phenolic and aliphatic organic acids. Their relative contents in cultivars were assessed via principle component analysis (PCA) and orthogonal projection to latent structures analysis (OPLS). Impact of the different extraction methods (decoction, infusion and maceration) was compared by quantitative 1H NMR spectroscopy, revealing cold maceration to be optimal for preserving anthocyanins, whereas infusion was more suited for recovering organic acids. The metabolite pattern revealed by the different extraction methods was found in good correlation for their ability to inhibit α-glucosidase enzyme.