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Publikationen - Natur- und Wirkstoffchemie

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Publikation

Farag, M. A.; Zayed, A.; Sallam, I. E.; Abdelwareth, A.; Wessjohann, L. A.; Metabolomics-based approach for coffee beverage improvement in the context of processing, brewing methods, and quality attributes Foods 11, 864, (2022) DOI: 10.3390/foods11060864

Coffee is a worldwide beverage of increasing consumption, owing to its unique flavor and several health benefits. Metabolites of coffee are numerous and could be classified on various bases, of which some are endogenous to coffee seeds, i.e., alkaloids, diterpenes, sugars, and amino acids, while others are generated during coffee processing, for example during roasting and brewing, such as furans, pyrazines, and melanoidins. As a beverage, it provides various distinct flavors, i.e., sourness, bitterness, and an astringent taste attributed to the presence of carboxylic acids, alkaloids, and chlorogenic acids. To resolve such a complex chemical makeup and to relate chemical composition to coffee effects, large-scale metabolomics technologies are being increasingly reported in the literature for proof of coffee quality and efficacy. This review summarizes the applications of various mass spectrometry (MS)- and nuclear magnetic resonance (NMR)-based metabolomics technologies in determining the impact of coffee breeding, origin, roasting, and brewing on coffee chemical composition, and considers this in relation to quality control (QC) determination, for example, by classifying defected and non-defected seeds or detecting the adulteration of raw materials. Resolving the coffee metabolome can aid future attempts to yield coffee seeds of desirable traits and best flavor types.
Publikation

Farag, M. A.; Abdelwareth, A.; Zayed, A.; Eissa, T. F.; Dokalahy, E.; Frolov, A.; Wessjohann, L. A.; A comparative metabolomics approach for egyptian mango fruits classification based on UV and UPLC/MS and in relation to its antioxidant effect Foods 11, 2127, (2022) DOI: 10.3390/foods11142127

Mango (Mangifera indica L.) is a tropical climacteric fruit that encompasses a myriad of metabolites mediating for its nutritive value, unique taste, flavor, and medicinal uses. Egypt is among the top mango producers worldwide, albeit little characterization has been made toward its fruits’ chemical composition. This study aims to assess metabolites difference via comparative profiling and fingerprinting of Egyptian mango in context to its cultivar (cv.) type and/or growth province. To achieve such goal, hyphenated chromatographic techniques (UPLC/MS) and UV spectroscopy were employed and coupled to multivariate data analysis for Egyptian mango fruits’ classification for the first time. UPLC/MS led to the detection of a total of 47 peaks identified based on their elution times and MS data, belonging to tannins as gallic acid esters, flavonoids, xanthones, phenolic acids and oxylipids. UV/Vis spectra of mango fruits showed similar absorption patterns mostly attributed to the phenolic metabolites, i.e., gallic acid derivatives and phenolic acids showing λmax at ca. 240 and 270 nm. Modeling of both UPLC/MS and UV data sets revealed that cv. effect predominated over geographical origin in fruits segregation. Awees (AS) cv. showed the richest phenolic content and in agreement for its recognition as a premium cv. of mango in Egypt. Results of total phenolic content (TPC) assay revealed that AS was the richest in TPC at 179.1 mg GAE/g extract, while Langara from Ismailia (LI) showed the strongest antioxidant effect at 0.41 mg TE/g extract. Partial least square modeling of UV fingerprint with antioxidant action annotated gallates as potential contributor to antioxidant effect though without identification of exact moieties based on UPLC/MS. The study is considered the first-time investigation of Egyptian mango to aid unravel phytoconstituents responsible for fruits benefits using a metabolomics approach.
Publikation

El-Hawary, E. A.; Zayed, A.; Laub, A.; Modolo, L. V.; Wessjohann, L.; Farag, M. A.; How does LC/MS compare to UV in coffee authentication and determination of antioxidant effects? Brazilian and Middle Eastern coffee as case studies Antioxidants 11, 131, (2022) DOI: 10.3390/antiox11010131

Coffee is a popular beverage owing to its unique flavor and diverse health benefits. The current study aimed at investigating the antioxidant activity, in relation to the phytochemical composition, of authenticated Brazilian green and roasted Coffea arabica and C. robusta, along with 15 commercial specimens collected from the Middle East. Ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-ESI–HRMS) and UV spectrometry were employed for profiling and fingerprinting, respectively. With the aid of global natural product social molecular networking (GNPS), a total of 88 peaks were annotated as belonging to different chemical classes, of which 11 metabolites are reported for the first time in coffee seeds. Moreover, chemometric tools showed comparable results between both platforms, with more advantages for UV in the annotation of roasting products, suggesting that UV can serve as a discriminative tool. Additionally, antioxidant assays coupled with the UHPLC-ESI–HRMS dataset using partial least-squares discriminant analysis (PLS-DA) demonstrated that caffeoylquinic acid and caffeine were potential antioxidant markers in unroasted coffee versus dicaffeoyl quinolactone and melanoidins in roasted coffee. The study presents a multiplex metabolomics approach to the quality control of coffee, one of the most consumed beverages.
Publikation

El Harrar, T.; Davari, M. D.; Jaeger, K.-E.; Schwaneberg, U.; Gohlke, H.; Critical assessment of structure-based approaches to improve protein resistance in aqueous ionic liquids by enzyme-wide saturation mutagenesis Comp Struct Biotechnol J 20, 399-409, (2022) DOI: 10.1016/j.csbj.2021.12.018

Ionic liquids (IL) and aqueous ionic liquids (aIL) are attractive (co-)solvents for green industrial processes involving biocatalysts, but often reduce enzyme activity. Experimental and computational methods are applied to predict favorable substitution sites and, most often, subsequent site-directed surface charge modifications are introduced to enhance enzyme resistance towards aIL. However, almost no studies evaluate the prediction precision with random mutagenesis or the application of simple data-driven filtering processes. Here, we systematically and rigorously evaluated the performance of 22 previously described structure-based approaches to increase enzyme resistance to aIL based on an experimental complete site-saturation mutagenesis library of Bacillus subtilis Lipase A (BsLipA) screened against four aIL. We show that, surprisingly, most of the approaches yield low gain-in-precision (GiP) values, particularly for predicting relevant positions: 14 approaches perform worse than random mutagenesis. Encouragingly, exploiting experimental information on the thermostability of BsLipA or structural weak spots of BsLipA predicted by rigidity theory yields GiP = 3.03 and 2.39 for relevant variants and GiP = 1.61 and 1.41 for relevant positions. Combining five simple-to-compute physicochemical and evolutionary properties substantially increases the precision of predicting relevant variants and positions, yielding GiP = 3.35 and 1.29. Finally, combining these properties with predictions of structural weak spots identified by rigidity theory additionally improves GiP for relevant variants up to 4-fold to ∼10 and sustains or increases GiP for relevant positions, resulting in a prediction precision of ∼ 90% compared to ∼ 9% in random mutagenesis. This combination should be applicable to other enzyme systems for guiding protein engineering approaches towards improved aIL resistance.
Publikation

Dube, M.; Raphane, B.; Sethebe, B.; Seputhe, N.; Tiroyakgosi, T.; Imming, P.; Häberli, C.; Keiser, J.; Arnold, N.; Andrae-Marobela, K.; Medicinal plant preparations administered by Botswana traditional health practitioners for treatment of worm infections show anthelmintic activities Plants 11, 2945, (2022) DOI: 10.3390/plants11212945

Schistosomiasis and soil-transmitted helminths are some of the priority neglected tropical diseases (NTDs) targeted for elimination by the World Health Organization (WHO). They are prevalent in Botswana and although Botswana has begun mass drug administration with the hope of eliminating soil-transmitted helminths as a public health problem, the prevalence of schistosomiasis does not meet the threshold required to warrant large-scale interventions. Although Botswana has a modern healthcare system, many people in Botswana rely on traditional medicine to treat worm infections and schistosomiasis. In this study, ten plant species used by traditional health practitioners against worm infections were collected and tested against Ancylostoma ceylanicum (zoonotic hookworm), Heligmosomoides polygyrus (roundworm of rodents), Necator americanus (New World hookworm), Schistosoma mansoni (blood fluke) [adult and newly transformed schistosomula (NTS)], Strongyloides ratti (threadworm) and Trichuris muris (nematode parasite of mice) in vitro. Extracts of two plants, Laphangium luteoalbum and Commiphora pyaracanthoides, displayed promising anthelmintic activity against NTS and adult S. mansoni, respectively. L. luteoalbum displayed 85.4% activity at 1 μg/mL against NTS, while C. pyracanthoides displayed 78.5% activity against adult S. mansoni at 10 μg/mL.
Publikation

Dube, M.; Llanes, D.; Saoud, M.; Rennert, R.; Imming, P.; Häberli, C.; Keiser, J.; Arnold, N.; Albatrellus confluens (Alb. & Schwein.) Kotl. & Pouz.: Natural fungal compounds and synthetic derivatives with in vitro anthelmintic activities and antiproliferative effects against two human cancer cell lines Molecules 27, 2950, (2022) DOI: 10.3390/molecules27092950

Neglected tropical diseases affect the world’s poorest populations with soil-transmitted helminthiasis and schistosomiasis being among the most prevalent ones. Mass drug administration is currently the most important control measure, but the use of the few available drugs is giving rise to increased resistance of the parasites to the drugs. Different approaches are needed to come up with new therapeutic agents against these helminths. Fungi are a source of secondary metabolites, but most fungi remain largely uninvestigated as anthelmintics. In this report, the anthelmintic activity of Albatrellus confluens against Caenorhabditis elegans was investigated using bio-assay guided isolation. Grifolin (1) and neogrifolin (2) were identified as responsible for the anthelmintic activity. Derivatives 4–6 were synthesized to investigate the effect of varying the prenyl chain length on anthelmintic activity. The isolated compounds 1 and 2 and synthetic derivatives 4–6, as well as their educts 7–10, were tested against Schistosoma mansoni (adult and newly transformed schistosomula), Strongyloides ratti, Heligmosomoides polygyrus, Necator americanus, and Ancylostoma ceylanicum. Prenyl-2-orcinol (4) and geranylgeranyl-2-orcinol (6) showed promising activity against newly transformed schistosomula. The compounds 1, 2, 4, 5, and 6 were also screened for antiproliferative or cytotoxic activity against two human cancer lines, viz. prostate adenocarcinoma cells (PC-3) and colorectal adenocarcinoma cells (HT-29). Compound 6 was determined to be the most effective against both cell lines with IC50 values of 16.1 µM in PC-3 prostate cells and 33.7 µM in HT-29 colorectal cells.
Publikation

Dippe, M.; Davari, M. D.; Weigel, B.; Heinke, R.; Vogt, T.; Wessjohann, L. A.; Altering the regiospecificity of a catechol O‐methyltransferase through rational design: Vanilloid vs. isovanilloid motifs in the B‐ring of flavonoids ChemCatChem 14, e202200511, (2022) DOI: 10.1002/cctc.202200511

Rational re-design of the substrate pocket of phenylpropanoid-flavonoid O-methyltransferase (PFOMT) from Mesembryanthe-mum crystallinum, an enzyme that selectively methylates the 3’-position (= meta-position) in catechol-moieties of flavonoids to guiacol-moieties, provided the basis for the generation of variants with opposite, i. e. 4’- (para-) regioselectivity and enhanced catalytic efficiency. A double variant (Y51R/N202W) identified through a newly developed colorimetric assay efficiently modified the para-position in flavanone and flavano-nol substrates, providing access to the sweetener molecule hesperetin and other rare plant flavonoids having an isovanil-loid motif.
Publikation

Díaz-Bustamante, M. L.; Fernández-Niño, M.; Reyes, L. H.; Alvarez Solano, O. A.; Multiscale approach to dairy products design Frontiers in Chemical Engineering 4, 830314, (2022) DOI: 10.3389/fceng.2022.830314

Dairy products are among the most popular nutritious foods in the world. Understanding the relationship between the composition, process, and structural properties at different scales (molecular, microscopic, and macroscopic) is fundamental to designing dairy products. This review highlights the need to analyze this relationship from different scales as an essential step during product design through a multiscale approach.
Publikation

Zhang, Y.; Cui, L.; Lu, Y.; He, J.; Hussain, H.; Xie, L.; Sun, X.; Meng, Z.; Cao, G.; Qin, D.; Wang, D.; Characterization of silver nanoparticles synthesized by leaves of Lonicera japonica thunb International Journal of Nanomedicine 17, 1647-1657, (2022) DOI: 10.2147/ijn.s356919

Background: The leaves of L. japonica (LLJ) are widely used as medicine in China. It is rich in caffeoylquinic acids, flavonoids and iridoid glycosides and has strong reducing capacities. Therefore, it can be used as a green material to synthesize silver nanoparticles.Methods: LLJ was used as a reducing agent to produce the LLJ-mediated silver nanoparticles (LLJ-AgNPs). The structure and physicochemical properties of LLJ-AgNPs were characterized by ultraviolet spectroscopy (UV-Vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and x-ray powder diffraction (XRD). Antioxidant activity of LLJ-AgNPs was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging. Antibacterial activity was determined by 96 well plates (AGAR) gradient dilution, while the anticancer potential was determined by MTT assay.Results: The results showed LLJ-AgNPs had a spherical structure with the maximum UV-Vis absorption at 400 nm. In addition, LLJAgNPs exhibited excellent antioxidant properties, where the free radical scavenging rate of LLJ-AgNPs was increased from 39% to 92% at concentrations from 0.25 to 1.0 mg/mL. Moreover, LLJ-AgNPs displayed excellent antibacterial properties against E. coli and Salmonella at room temperature, with minimum inhibitory values of 10−6 and 10−5 g/L, respectively. In addition, the synthetic LLJAgNPs exhibited a better inhibition effect in the proliferation of cancer cells (HepG2, MDA-MB −231, and Hela cells).Conclusion: The present study provides a green approach to synthesize LLJ-AgNPs. All those findings illustrated that the produced LLJ-AgNPs can be used as an economical and efficient functional material for further applications in food and pharmaceutical fields.
Publikation

Zayed, A.; Abdelwareth, A.; Mohamed, T. A.; Fahmy, H. A.; Porzel, A.; Wessjohann, L. A.; Farag, M. A.; Dissecting coffee seeds metabolome in context of genotype, roasting degree, and blending in the Middle East using NMR and GC/MS techniques Food Chem. 373, 131452, (2022) DOI: 10.1016/j.foodchem.2021.131452

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.
  • Die Leibniz-Gemeinschaft
  • Digitalisierung in der Landwirtschaft
  • Martin-Luther Universität Halle
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