Browsing by Author "Wessjohann L.A."

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    Effect of oxylipins, terpenoid precursors and wounding on soft corals' secondary metabolism as analyzed via UPLC/MS and chemometrics
    (MDPI AG, 2017) Farag M.A.; Westphal H.; Eissa T.F.; Wessjohann L.A.; Meyer A.; Department of Pharmacognosy; College of Pharmacy; Cairo University; Kasr El Aini St.; Cairo; 11562; Egypt; Department of Chemistry; School of Sciences and Engineering; American University in Cairo; New Cairo; 11835; Egypt; Leibniz Centre for Tropical Marine Research; Fahrenheit Str.6; Bremen; D-28359; Germany; Department of Geosciences; Bremen University; Fahrenheit Str.6; Bremen; D-28359; Germany; Department of Pharmacognosy; College of Pharmacy; Modern Science and Arts University; Cairo; 12566; Egypt; Department of Bioorganic Chemistry; Leibniz Institute of Plant Biochemistry; Weinberg 3; Halle; D-06120; Germany
    The effect of three oxylipin analogues, a terpenoid intermediate and wounding on the secondary metabolism of the soft corals Sarcophyton glaucum and Lobophyton pauciflorum was assessed. Examined oxylipins included prostaglandin (PG-E1), methyl jasmonate (MeJA), and arachidonic acid (AA) in addition to the diterpene precursor geranylgeranylpyrophosphate (GGP). Post-elicitation, metabolites were extracted from coral heads and analyzed via UPLC-MS followed by multivariate data analyses. Both supervised and unsupervised data analyses were used for sample classification. Multivariate data analysis revealed clear segregation of PG-E1 and MeJA elicited S. glaucum at 24 and 48 h post elicitation from other elicitor samples and unelicited control group. PG-E1 was found more effective in upregulating S. glaucum terpene/sterol levels compared to MeJA. Metabolites showing upregulation in S. glaucum include campestene-triol and a cembranoid, detected at ca. 30- and 2-fold higher levels compared to unelicited corals. Such an elicitation effect was less notable in the other coral species L. pauciflorum, suggesting a differential oxylipin response in soft corals. Compared to MeJA and PG, no elicitation effect was observed for GGP, AA or wounding on the metabolism of either coral species. � 2017 by the authors. Licensee MDPI, Basel, Switzerland.
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    Phytochemical profiles and antimicrobial activities of Allium cepa red cv. and A. sativum subjected to different drying methods: A comparative MS-based metabolomics
    (Institute of Electrical and Electronics Engineers Inc., 2017) Farag M.A.; Ali S.E.; Hodaya R.H.; El-Seedi H.R.; Sultani H.N.; Laub A.; Eissa T.F.; Abou-Zaid F.O.F.; Wessjohann L.A.; Pharmacognosy Department; College of Pharmacy; Cairo University; Kasr el Aini St.; Cairo; Egypt; Department of Pharmaceutical Biology; Faculty of Pharmacy and Biotechnology; German University in Cairo; P.B. 11835; Cairo; Egypt; Plant Production Department; Desert Research Center; P.B. 11714; Cairo; Egypt; Division of Pharmacognosy; Department of Medicinal Chemistry; Uppsala University; Box 574; Uppsala; SE-75 123; Sweden; Department of Chemistry; Faculty of Science; El-Menoufia University; Shebin El-Kom; 32512; Egypt; Leibniz Institute of Plant Biochemistry; Dept. Bioorganic Chemistry; Weinberg 3; Halle (Saale); D-06120; Germany; Pharmacognosy Department; College of Pharmacy; Modern Science and Arts University; P.B. 12566; Cairo; Egypt
    Plants of the Allium genus produce sulphur compounds that give them a characteristic (alliaceous) flavour and mediate for their medicinal use. In this study, the chemical composition and antimicrobial properties of Allium cepa red cv. and A. sativum in the context of three different drying processes were assessed using metabolomics. Bulbs were dried using either microwave, air drying, or freeze drying and further subjected to chemical analysis of their composition of volatile and non-volatile metabolites. Volatiles were collected using solid phase micro-extraction (SPME) coupled to gas chromatography-mass spectrometry (GC/MS) with 42 identified volatiles including 30 sulphur compounds, four nitriles, three aromatics, and three esters. Profiling of the polar non-volatile metabolites via ultra-performance liquid chromatography coupled to high resolution MS (UPLC/MS) annotated 51 metabolites including dipeptides, flavonoids, phenolic acids, and fatty acids. Major peaks in GC/MS or UPLC/MS contributing to the discrimination between A. sativum and A. cepa red cv. were assigned to sulphur compounds and flavonoids. Whereas sulphur conjugates amounted to the major forms in A. sativum, flavonoids predominated in the chemical composition of A. cepa red cv. With regard to drying impact on Allium metabolites, notable and clear separations among specimens were revealed using principal component analysis (PCA). The PCA scores plot of the UPLC/MS dataset showed closer metabolite composition of microwave dried specimens to freeze dried ones, and distant from air dried bulbs, observed in both A. cepa and A. sativum. Compared to GC/MS, the UPLC/MS derived PCA model was more consistent and better in assessing the impact of drying on Allium metabolism. A phthalate derivative was found exclusively in a commercial garlic preparation via GC/MS, of yet unknown origin. The freeze dried samples of both Allium species exhibited stronger antimicrobial activities compared to dried specimens with A. sativum being in general more active than A. cepa red cv. � 2017 by the authors.