- Ergebnisse als:
- Druckansicht
- Endnote (RIS)
- BibTeX
- Tabelle: CSV | HTML
Publikation
Publikation
Publikation
Publikation
Publikation
Publikation
Publikation
Publikation
Publikation
Publikation
Leitbild und Forschungsprofil
Molekulare Signalverarbeitung
Natur- und Wirkstoffchemie
Biochemie pflanzlicher Interaktionen
Stoffwechsel- und Zellbiologie
Unabhängige Nachwuchsgruppen
Program Center MetaCom
Publikationen
Gute Wissenschaftliche Praxis
Forschungsförderung
Netzwerke und Verbundprojekte
Symposien und Kolloquien
Alumni-Forschungsgruppen
Publikationen
Publikation
The production of fine-flavor cocoa represents a promising avenue to enhance socioeconomic development in Colombia and Latin America. Premium chocolate is obtained through a post-harvesting process, which relies on semi-standardized techniques. The change in the metabolic profile during cocoa processing considerably impacts flavor and nutraceutical properties of the final product. Understanding this impact considering both volatiles and non-volatile compounds is crucial for process and product re-engineering of cocoa post-harvesting. Consequently, this work studied the metabolic composition of cocoa liquor by untargeted metabolomics and lipidomics. This approach offered a comprehensive view of cocoa biochemistry, considering compounds associated with bioactivity and flavor in cocoa liquor. Their variations were traced back over the cocoa processing (i.e., drying, and roasting), highlighting their impact on flavor development and the nutraceutical properties. These results represent the basis for future studies aimed to re-engineer cocoa post-harvesting considering the variation of key flavor and bioactive compounds over processing.
Publikation
Tomatoes show diverse phytochemical attributes that contribute to their nutritive and health values. This study comprehensively dissects primary and secondary metabolite profiles of seven tomato varieties. UHPLC-qTOF-MS assisted molecular networking was used to monitor 206 metabolites, 30 of which were first-time to be reported. Flavonoids, as valuable antioxidants, were enriched in light-colored tomatoes (golden sweet, sun gold, and yellow plum) versus high tomatoside A, an antihyperglycemic saponin, in cherry bomb and red plum varieties. UV–Vis analysis revealed similar results with a strong absorbance corresponding to rich phenolic content in light varieties. GC–MS unveiled monosaccharides as the main contributors to samples’ segregation, found abundant in San Marzano tomato accounting for its sweet flavor. Fruits also demonstrated potential antioxidant activities in correlation to their flavonoids and phospholipids. This work provides a complete map of tomatoes’ metabolome heterogeneity for future breeding programs and a comparative approach utilizing different metabolomic platforms for tomato analysis.
Publikation
M. oleifera known as “miracle tree” is increasingly used in nutraceuticals for the reported health effects and nutritional value of its leaves. This study presents the first metabolome profiling of M. oleifera leaves of African origin using different solvent polarities via HR-UPLC/MS based molecular networking followed by multivariate data analyses for samples classification. 119 Chemicals were characterized in both positive and negative modes belonging to 8 classes viz. phenolic acids, flavonoids, peptides, fatty acids/amides, sulfolipids, glucosinolates and carotenoids. New metabolites i.e., polyphenolics, fatty acids, in addition to a new class of sulfolipids were annotated for the first time in Moringa leaves. In vitro anti-inflammatory and anti-aging bioassays of the leaf extracts were assessed and in correlation to their metabolite profile via multivariate data analyses. Kaempferol, quercetin and apigenin-O/C-glycosides, fatty acyl amides and carotenoids appeared crucial for biological activities and leaves origin discrimination.
Publikation
The impact of cocoa lipid content on chocolate quality has been extensively described. Nevertheless, few studies have elucidated the cocoa lipid composition and their bioactive properties, focusing only on specific lipids. In the present study the lipidome of fine-flavor cocoa fermentation was analyzed using LC-MS-QTOF and a Machine Learning model to assess potential bioactivity was developed. Our results revealed that the cocoa lipidome, comprised mainly of fatty acyls and glycerophospholipids, remains stable during fine-flavor cocoa fermentations. Also, several Machine Learning algorithms were trained to explore potential biological activity among the identified lipids. We found that K-Nearest Neighbors had the best performance. This model was used to classify the identified lipids as bioactive or non-bioactive, nominating 28 molecules as potential bioactive lipids. None of these compounds have been previously reported as bioactive. Our work is the first untargeted lipidomic study and systematic effort to investigate potential bioactivity in fine-flavor cocoa lipids.
Publikation
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
With a favored taste and various bioactivities, coffee has been consumed as a daily beverage worldwide. The current study presented a multi-faceted comparative metabolomics approach dissecting commercially available coffee products in the Middle East region for quality assessment and functional food purposes using NMR and GC/MS platforms. NMR metabolites fingerprinting led to identification of 18 metabolites and quantification (qNMR) of six prominent markers for standardization purposes. An increase of β-ethanolamine (MEA) reported for the first time, 5-(hydroxymethyl) furfural (5-HMF), concurrent with a reduction in chlorogenic acid, kahweol, and sucrose levels post roasting as revealed using multivariate data analyses (MVA). The diterpenes kahweol and cafestol were identified in green and roasted Coffea arabica, while 16-O-methyl cafestol in roasted C. robusta. Moreover, GC/MS identified a total of 143 metabolites belonging to 15 different chemical classes, with fructose found enriched in green C. robusta versus fatty acids abundance, i.e., palmitic and stearic acids in C. arabica confirming NMR results. These potential results aided to identify novel quality control attributes, i.e., ethanolamine, for coffee in the Middle East region and have yet to be confirmed in other coffee specimens.
Publikation
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
Ziziphus plants are well recognized for their nutritive and medicinal value worldwide, albeit their chemical profile has yet to be fully reported. The secondary metabolites profile of three traditionally used Ziziphus leaf accessions was investigated via ultra-high performance liquid chromatography coupled to photodiode array and electrospray ionization mass detectors (UHPLC/PDA/ESI-MS). A total of 102 metabolites were characterized revealing the first holistic approach onto Ziziphus leaf metabolome and to include the first report of several novel flavonoids and cyclopeptide alkaloids. Fragmentation pattern for cyclopeptide alkaloids was proposed via ESI-MS. Principal component analysis (PCA) revealed close metabolite resemblance among Z. spina-christi and Z. mauritiana leaf specimens found enriched in saponins and distinct from that of Z. jujuba in which quercetin-3-O-(2-pentosyl)-rhamnoside was most abundant. Further, in-vitro antioxidant, anti-inflammatory and antidiabetic assays revealed for Z. spina-christi and Z. mauritiana strong effects compared to Z. jujuba and in correlation with their metabolites repertoire.
Publikation
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
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.