Browsing by Author "Eldahshan O."

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    Acylated flavonol diglucosides from Ammania auriculata
    (Verlag der Zeitschrift fur Naturforschung, 2015) Nawwar M.; Ayoub N.; El-Raey M.; Zaghloul S.; Hashem A.; Mostafa E.; Eldahshan O.; Lindequist U.; Linscheid M.W.; National Research Center; Department of Phytochemistry and Plant Systematics; El Bohooth Str.; P.O. 12622; Dokki; Cairo; Egypt; Faculty of Pharmacy; Department of Pharmacognosy; Ain-Shams University; Cairo; Egypt; October University for Modern Sciences and Arts; 6th October City; Egypt; Department of Pharmacognosy; Faculty of Pharmacy; Institute of Pharmacy; Pharmaceutical Biology; Ernst-Moritz-Arndt-Universit�t Greifswald; Greifswald; Germany; Laboratory of Applied Analytical and Environmental Chemistry; Department of Chemistry; Humboldt-Universit�t zu Berlin; Berlin; Germany
    Chemical investigation of the extract of the whole Ammania auriculata plant resulted in the identification of 13 polyphenols, including the hitherto unknown flavonoids, kaempferol 3-O-?-(6?-galloylglucopyranoside)- 7-O-?-glucopyranoside, and its quercetin analogue. The structures of all isolates were elucidated by conventional methods, spectroscopic analysis, including 1D and 2D NMR, and by HRESI-MS as well.
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    Polyphenols in Ammania auriculata: Structures, antioxidative activity and cytotoxicity
    (Govi-Verlag Pharmazeutischer Verlag GmbH, 2014) Nawwar M.A.; Youb N.A.; El-Raey M.A.; Zaghloul S.S.; Hashem A.M.; Mostafa E.S.; Eldahshan O.; Werner V.; Becker A.; Haertel B.; Lindequist U.; Linscheid M.W.; Department of Phytochemistry and Plant Systematics; National Research Center; Dokki Cairo; Egypt; Department of Pharmacognosy; Faculty of Pharmacy; Ain-Shams University; Cairo; Egypt; October University for Modern Sciences and Arts; 6th October City; Egypt; Institute of Pharmacy; Pharmaceutical Biology; Ernst-Moritz-Arndt-Universit�t; Greifswald; Mecklenburg-Vorpommern; Germany; Department of Chemistry; Laboratory of Applied Analytical and Environmental Chemistry; Humboldt -University; Berlin; Germany
    Chemical and biological investigations of the extract of Ammania auriculata (Lytheraceae) resulted in the identification of eight polyphenols (1 - 8) for the first time from this plant, including the gallotannin, 2,3,6-tri-O-galloyl-(?,?)-4C1-glucopyranose (8), for which 1D and 2D-NMR spectra were recorded and assigned for the first time. The structures of all isolates (1 - 8) were elucidated by conventional methods, spectroscopic analysis, including 1D and 2D NMR, and by HR-ESIMS as well. All of the isolated compounds were evaluated for their antioxidant activities, determined by the DPPH and ORAC methods and for their cytotoxicity against the keratinocyte cell line HaCaT using the neutral red assay (NRU) and cell cycle analysis. Compounds 1, 3, 4, 5, and 6 significantly inhibited reactive oxygen species production with ED50 values between 3.22 and 9.79 ?g/ml. Compounds 1, 3, 4, and 5 showed cytotoxic activity against HaCaT cells with IC50 values between 30.7 and 84.1 ?g/ml. The new galloyl glucose (8) was found not cytotoxic. Ellagitannins, 2,3-hexahydroxy-(?/?)-glucopyranose (1) and 1-O-galloyl 2,3-hexahydroxy-(?)-glucopyranose (5) possess remarkable antioxidative and comparably weak cytotoxic activity.