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Öğe Anatomy, trichome micromorphology and phytochemical profile of Stachys rizeensis R.Bhattacharjee from Turkey(Elsevier, 2022) Gercek, Yusuf Can; Sahin, Aydan Acar; Bayram, Nesrin Ecem; Celik, Saffet; Sefali, Abdurrahman; Gidik, Betul; Oz, Gul CevahirIn recent years, the popularity of natural products and natural product formulations has increased due to their beneficial effects on health. As a part of this trend, Lamiaceae family members have attracted attention due to their rich bioactive properties. Although the Stachys rizeensis R.Bhattacharjee plant is an endemic plant species in Turkey, no studies focus on its characterization. Hence, the present study aims to demonstrate the anatomical, morphological and phytochemical characterization of S. rizeensis in Turkey. In the first stage of the study, anatomical and trichome morphological characterization was performed to contribute to the taxonomic definition of S. rizeensis was found to be anatomically different from some other previously studied Stachys sp. by showing lacunar collenchyma type, uncertain cambium at the corners, two or three rows of endodermis in certain areas in the stem and two rows of palisade parenchyma, capitate and peltate glandular trichomes in the leaf. In the second stage, the phenolic profile, total phenolic/flavonoid content and antioxidant activity of the plant extracts prepared using solvents with different polarities (ethanol, methanol, water, ethyl acetate and hexane) were tested to determine the phytochemical content of the plant. The phytochem-ical analysis supported by chemometric analysis (PCA and HCA) revealed that methanol was the most efficient organic solvent for the extraction of the phytochemical compounds of the plant. Additionally, it was observed that chlorogenic acid (1842.40-217,086.19 mg/kg), verbascoside (2591.43-204,429.81 mg/kg), luteolin (3579.56-88,636.14 mg/kg) and kaempferol (9706.30-50,340.93 mg/kg) compounds were present at maximum levels in this plant, in which 31 different phenolic compounds were scanned using LC-MS/MS. In addition, results obtained from the phytochemical analysis revealed that S. rizeensis is a valuable plant that can be used for medical protection/treatment and that it could also have a variety of culinary applica-tions. The present study served as the first original report regarding the chemical profile and anatomical characteristics of S. rizeensis (Lamiaceae) from Turkey. (C) 2022 SAAB. Published by Elsevier B.V. All rights reserved.Öğe Chemical Analysis and Antimicrobial Effect of Propolis from Hakkari Province of Turkey against Some Pathogenic Microorganisms(İstanbul Üniversitesi, 2017) Bayram, Sinan; Bayram, Nesrin Ecem; Gercek, Yusuf Can; Aydogan, Mehmet Nuri; Oz, Gul CevahirThis study was performed to investigate the antimicrobial effect of propolis from Hakkari province of Turkey and its chemical content by Gas Chromatography–Mass Spectroscopy. In vitro inhibitory activity of propolis was studied by the disc diffusion method against six gram positive, three gram negative bacteria and one yeast like fungi. As a result of chemical analysis, the total flavonoid ratio of the propolis sample was found to be higher than the other compound groups. Pinostrobin chalcone, pinocembrin and chrysin were identified as major flavonoids. Also, all microorganisms tested were susceptible to the propolis extract except for Klebsiella pneumoniae. Minimum inhibition concentration (MIC) values were determined by microbroth dilution assay. MIC values against microorganisms ranged from 25 to 200 µg/mL. Antimicrobial susceptibility test results showed that inhibitory effect our propolis sample was somewhat weaker than ampicillin, but it had a broader spectrum.Öğe Quantification of phenolics by LC-MS/MS of monofloral and polyfloral Honey: Evaluation of the greenness of the method with MoGAPI and MoGSA(Elsevier, 2025) Gercek, Yusuf Can; Basturk, Fatma Nur; Ozkok, Asli; Oz, Gul Cevahir; Bayram, Nesrin EcemThis study evaluated the physicochemical properties, total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, proanthocyanidin content, and polyphenolic profiles of monofloral and multifloral honey samples produced in T & uuml;rkiye. In addition, the greenness of the analytical method was assessed using two different evaluation tools: MoGSA and MoGAPI. The TPC and TFC values for multifloral honeys ranged from 0.18-0.65 mg GAE/g and 0.01-0.09 mg QE/g, respectively, whereas for monofloral honeys, these values ranged from 0.16-0.98 mg GAE/g and 0.01-0.37 mg QE/g. The highest CUPRAC and DPPH values were observed in Erica spp. honey, consistent with its TFC and total individual polyphenolic compound results. Notably, the Erica spp. honey sample exhibited a significantly higher gallic acid content (26.13 mu g/g) compared to the other samples. These findings suggest that Erica spp. honey characterized by its high TPC, antioxidant activity, and distinctive polyphenolic profile, may serve as a notable dietary source of antioxidants. Additionally, the MoGAPI and MoGSA scores of the method were determined to be 84 and 91.67, respectively, demonstrating its high environmental sustainability.Öğe Screening for antioxidant capacity, pollen types and phytochemical profile by GC/MS and UHPLC from propolis(Mattioli 1885, 2020) Bayram, Nesrin Ecem; Gercek, Yusuf Can; Oz, Gul CevahirPropolis is a resinous mixture collected by honeybees from different parts of plants such as poplars, birches, alders, conifers, pines, palms and willows. This study aims to determine pollen types (by light microscope), chemical compound profile (by GC-MS), fatty acid composition (by GC-MS), total phenolic content (by the Folin-Ciocalteu method), total flavonoid content (by the aluminium chloride method) and antioxidant capacity (by the CUPRAC, ABTS and CERAC methods) of a propolis sample from the western part of Istanbul, Turkey. As a result of microscopic analysis of the sample, pollen types of taxa belonging to 27 plant families were diagnosed. The GC-MS analysis of propolis revealed the presence of 38 phytochemical constituents that may contribute to its quality. Of these compounds, rates of 4H-1-benzopyran-4-one, 2,3-dihydro-5,7-dihydroxy-2-phenyl-,(S) were highest. In addition, the concentrations of naringenin, pinocembrin and galangin were determined to be 2.45, 9.92 and 7.06 mg/ml by UHPLC analysis. The extract had significant antioxidant activity in all assays, with values of 282.8 +/- 9 mg TE/g in the CUPRAC, 425.7 +/- 18 mg TE/g in the CERAC and 186.4 +/- 8 mg TE/g in the ABTS assays. Antioxidant capacity of the propolis extract was positively associated with the total phenolic and flavonoid contents of the extract. Moreover, the major fatty acids were C20:1n9 (cis-11-eicosenoic acid), C22:1 (erucic acid) and C24:1 (nervonic acid). The results show that the propolis used in our study has important potential as an alternative food supplement and for cosmetic and therapeutic medicine and it can be used as an active agent in these areas.
