Person: TOPÇU, GÜLAÇTI
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Publication Metadata only Antioxidant, anticholinesterase, and antimicrobial activities and fatty acid constituents of Achillea cappadocica Hausskn. et Bornm.(2014-01-01) Ertas, Abdulselam; Boga, Mehmet; Hasimi, Nesrin; Yesil, Yeter; GOREN, AHMET CEYHAN; Topcu, GÜLAÇTI; Kolak, Ufuk; GÖREN, AHMET CEYHAN; TOPÇU, GÜLAÇTIThis study was the first fatty acid analysis and biological activity report on an endemic Achillea species, Achillea cappadocica Hausskn. et Bornm. The major compounds in the fatty acid were identified as oleic (34.7%), palmitic (23.1%), and linoleic acids (20.6%). The methanol and water extracts indicated higher ABTS cation radical scavenging activity than that of alpha-tocopherol and BHT at 100 mu g/mL. The acetone extract showed 70.62% inhibitory activity against butyrylcholinesterase at 200 mu g/mL. The acetone and methanol extracts exhibited moderate antimicrobial activity.Publication Metadata only Anticholinesterase and Antioxidant Activities of Natural Abietane Diterpenoids with Molecular Docking Studies(2020-01-01T00:00:00Z) TOPÇU, GÜLAÇTI; AKDEMİR, ATİLLA; Kolak, Ufuk; Ozturk, Mehmet; Boga, Mehmet; BAHADORİ, FATEMEH; Cakmar, Seda Damla Hatipoglu; TOPÇU, GÜLAÇTI; AKDEMİR, ATİLLA; BAHADORİ, FATEMEHBackground: Alzheimer-s Disease (AD) is one of the most prevalent causes of dementia in the world, and no drugs available that can provide a complete cure. Cholinergic neurons of the cerebral cortex of AD patients are lost due to increased activity of cholinesterase enzymes.Publication Metadata only Two new indole alkaloids from Vinca herbacea L.(2011-12-01T00:00:00Z) Boga, Mehmet; Kolak, Ufuk; Topcu, GÜLAÇTI; Bahadori, Fatemeh; Kartal, Murat; FARNSWORTH, Norman R.; TOPÇU, GÜLAÇTI; BAHADORİ, FATEMEH; KARTAL, MURATSix indole alkaloids were isolated from the aerial parts of Vinca herbacea Waldst. et Kit. Structures of the isolated compounds were elucidated as two new alkaloids, 10-methoxyraucaffrinoline (1) and 11-methoxyburnamine (2), and four known alkaloids, picrinine (3), burnamine (4), caboxine A (5) and elegantine (6) by intensive 1D-and 2D-NMR spectroscopic techniques. Antioxidant and anticholinesterase activities were investigated for the methanol, alkaloidal and non-alkaloidal extracts of V. herbacea and isolated alkaloids (1-3, 6). The alkaloidal extract was found to be active in the three tested antioxidant assays and exhibited significant lipid peroxidation inhibitory and DPPH free radical scavenging activities. The alkaloidal extract also exhibited high anticholinesterase activity against AChE and BChE enzymes similar to galanthamine. However, none of the tested alkaloids 1-3, and 6 were found to be active in the tested antioxidant and anticholinesterase systems. The alkaloids 1, 2, 4, and 6 were also evaluated for cytotoxic activity against the MCF7 and HT29 cell lines, and showed no activity. (C) 2011 Phytochemical Society of Europe. Published by Elsevier B. V. All rights reserved.Publication Open Access Chemical profile and biological activities of Veronica thymoides subsp pseudocinerea(2015-03-01) Ertas, Abdulselam; Boga, Mehmet; Kizil, Murat; Ceken, Bircan; GOREN, AHMET CEYHAN; Hasimi, Nesrin; Demirci, Serpil; Topcu, GÜLAÇTI; Kolak, Ufuk; GÖREN, AHMET CEYHAN; TOPÇU, GÜLAÇTIContext: In Turkey, Veronica species (Plantaginaceae) have been used as a diuretic and for wound healing in traditional medicine. Objective: To examine the fatty acid and essential oil profiles, the antioxidant, anticholinesterase, antimicrobial, and DNA damage effects of Veronica thymoides P.H. Davis subsp. pseudocinerea M.A. Fischer as a potential source of natural active compounds. Materials and methods: GC/MS was used to analyze essential oil and fatty acid obtained from whole plant. The antioxidant activity was evaluated by the beta-carotene-linoleic acid test system, DPPH-free and ABTS cation radicals scavenging, and cupric reducing antioxidant capacity assays. The anticholinesterase and antimicrobial activities were determined by Ellman and broth macrodillution methods, respectively. The effect of the methanol extract on DNA cleavage was investigated. Results: Hexatriacontene (21.0%) was found to be the main constituent in essential oil, and linoleic acid (25.2%) and palmitic acid (20.6%) in fatty acid. Methanol extract demonstrated the best IC50 values in lipid peroxidation (49.81 +/- 0.31 mu g/ml) and DPPH-free radical scavenging activity (15.32 +/- 0.17 mu g/ml). Methanol and water extracts possessed strong ABTS cation radical scavenging activity with IC50 values 9.15 +/- 0.28 and 8.90 +/- 0.14 mu g/ml, respectively. The acetone extract exhibited moderate butyrylcholinesterase inhibitory activity. The highest antimicrobial activity was determined in methanol extract against Escherichia coli with 31.25 mu g/ml MIC value. Inhibition of methanol extract on plasmid DNA cleavage by OH radicals was found to be 93.32% at 500 mu g/ml. Conclusion: The methanol extract having strong antioxidant and DNA damage effects could be investigated phytochemically to find natural active compounds.Publication Metadata only Indole Alkaloids from Vinca major and V. minor Growing in Turkey(2012-06-01T00:00:00Z) Bahadori, FATEMEH; Topcu, Gulacti; Boga, Mehmet; Turkekul, Ayla; Kolak, Ufuk; Kartal, MURAT; BAHADORİ, FATEMEH; TOPÇU, GÜLAÇTI; KARTAL, MURATA new indole alkaloid, 11-hydroxypolyneuridine, was isolated from Vinca major subsp. major L. and the known indole alkaloids vallesiachotamine and isovallesiachotamine from Vinca minor L. This is the first report on the alkaloids of both Vinca species growing in Turkey; vallesiachotamine and isovallesiachotamine were isolated from a Vinca species for the first time. V. minor may be considered as a new source for these two alkaloids due to their occurrence in high amount in the aerial parts of the plant. The alkaloid extracts of the two Vinca species were found to have high lipid peroxidation inhibitory and DPPH radical scavenging activities. Anticholinesterase activity of the extracts was also very strong.