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    A new iridoid skeleton from Galium asparagifolium and biological activity studies
    (Elsevier, 2022) Toktas, Umit; Sarikahya, Nazli Boke; Parlak, Cemal; Ozturk, Ismail; Kayalar, Husniye
    This study identifies the detailed phytochemical content and biological effects of Galium as-paragifolium, for the first time and gained one new iridoid aglycone ( 1 ), seven known iri-doid glycosides ( 2-8 ), two flavonoids ( 9-10 ), and one carbohydrate derivative ( 11 ) to the liter-ature. The 1D-, 2D-NMR analyses and ESI-Mass allowed us to resolve the structure of new compound as (1S,4aS, 8aS)-pyrano[4, 3-c] pyran-1, 4a, 5, 7, 8, 8a- hexahydro- 1- hydroxy-3-( 2- hydroxyethyl)- 8- methyl-8-carboxylic acid namely galiumic acid. The compounds 1-11 and extracts from G. asparagifolium were investigated in terms of cytotoxic activity by MTT assay, antioxidant activ-ity by DPPH method and antimicrobial activity by DDT and BMM methods. While all compounds and extracts did not show remarkable cytotoxicity, they had variable antimicrobial activities for a variety of gram-positive/gram-negative bacteria and yeast strains. Besides that, most of the compounds showed an-tioxidant effect with a wide range of DPPH% inhibition values. The structure of the new compound was also elucidated by some computational studies. (c) 2021 Elsevier B.V. All rights reserved.
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    X-ray fluorescence spectroscopic determination of heavy metals and trace elements in aerial parts of Origanum sipyleum L from Turkey
    (Pharmacotherapy Group, 2016) Durmuskahya, Cenk; Alp, Hakan; Hortooglu, Zehra Sinem; Toktas, Umit; Kayalar, Husniye
    Purpose: To determine the heavy metal and trace element composition of the powdered aerial parts of Origanum sipyleum L. and its water extract. Methods: The heavy metal and trace elements content of the powdered plant material and 2 % aqueous extract were evaluated by x-ray fluorescence spectroscopy with silicon drift detector SDD at a resolution of 145 eV and 10,000 pulses. The process conditions were 0.1 g sample weight, process time of 300 s at a voltage of 25 kV and 50 kV, and at a current of 0.5 and 1.0 mA under helium atmosphere. Results: The major elements, K, Ca and Na, known as macronutrients, constituted 11990, 10490 and 970 ppm of the powdered drug and 8910, 2991 and 810 ppm of the water extract, respectively. Among other constituents, arsenic, lead and uranium levels were < 1, 2.1 and < 3 ppm, respectively, in the powdered material while in the aqueous extract, the levels were < 1, < 2 and 200 ppm, respectively. Conclusion: O. sipyleum is a potential source of macro-and micronutrients from which useful food additives and health supplements can be derived.