Person: TOPÇU, GÜLAÇTI
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- PublicationMetadata onlyFingerprint NMR Analysis of Indole Alkaloids Skeleton Using 1D and 2D-NMR Techniques(2017-11-17T00:00:00Z) Topçu, Gülaçtı; TOPÇU, GÜLAÇTI
- PublicationMetadata onlyAntioxidant and anticholinesterase active constituents from Micromeria cilicica by radical-scavenging activity-guided fractionation(2011-05-01T00:00:00Z) Ozturk, Mehmet; Kolak, Ufuk; Topcu, GÜLAÇTI; Oksuz, Sevil; CHOUDHARY, M. Iqbal; TOPÇU, GÜLAÇTIFrom the acetone extract of Micromeria cilicica, two new (1 and 2) and five known (3-7) compounds were obtained through radical-scavenging activity guided isolation. Structures of the compounds were identified as piperitone 7-O-beta-D-glucoside (1), isothymonin 4--methyl ether (2), sudachitin (3), isomucronulatol (4), rutin (5), ursolic acid (6) and saccharose (7), based on UV, 1D-and 2D-NMR and mass spectroscopic techniques. The antioxidant potentials of the extract and the isolated compounds were established by using three radical-scavenging assays, namely, DPPH. scavenging, O-2(center dot-) scavenging and ABTS(center dot+) scavenging, besides beta-carotene bleaching assay. Particularly, the acetone extract showed a strong inhibition of lipid peroxidation by beta-carotene bleaching assay, with a result close to that of (+)-catechin. Among the pure compounds, rutin (5) showed the strongest lipid peroxidation inhibition and antiradical activity while both sudachitin (3) and isomucronulatol (4) exhibited noticeable ABTS(center dot+) scavenging activity. The anticholinesterase activity of the compounds (1-7) was also determined. Against acetylcholinesterase, they exhibited weak inhibition while compounds 3, 4 and 6 exhibited moderate inhibition against butyrylcholinesterase. (C) 2010 Elsevier Ltd. All rights reserved.
- PublicationOpen AccessSelective in-vitro Enzymes- Inhibitory Activities of Fingerprints Compounds of Salvia Species and Molecular Docking Simulations(2020-01-01T00:00:00Z) ÖZHAN KOCAKAYA, ŞAFAK; ERTAŞ, ABDULSELAM; Yener, Ismail; Ercan, Bahadir; VARHAN ORAL, ELİF; Akdeniz, Mehmet; Kaplaner, Erhan; TOPÇU, GÜLAÇTI; Kolak, Ufuk; TOPÇU, GÜLAÇTIRecently Nutrition and Food Chemistry researches have been focused on plants and their products or their secondary metabolites having anti-alzheimer, anti-cancer, anti-aging, and antioxidant properties. Among these plants Salvia L. (Lamiaceae) species come into prominence with their booster effects due to high antioxidant contents, which have over 900 species in the world and 98 in Turkey. Some Salvia species are already in use as herbal treatment of vessel stiffness, Dementia like problems and cancer. Recently some species of Salvia are of extensive research topic. In this study, inhibitory potentials of secondary metabolites, rosmarinic acid, salvigenin, salvianolic acid A and B, tanshinone I and IIA, cyrtotanshinone, dihydrotanshinone I, carnosic acid, carnosol, and danshensu sodium salt were investigated against acetylcholinesterase, butyrylcholinesterase, urease and tyrosinase enzymes both in-vitro and in slico in detail. Elevated inhibitory effects on acetyl-and butyryl-cholinesterase of dihydrotanshinone I (IC50: 1.50 +/- 0.02 and 0.50 +/- 0.01 mu g/mL, respectively), carnasol (IC50: 11.15 +/- 0.05 ve 3.92 +/- 0.03 mu g/mL) and carnosic acid (IC50: 31.83 +/- 0.65 ve 4.12 +/- 0.04 mu g/mL) were observed. Furthermore, all other secondary metabolites were active against butyrylcholinesterase. Anti-urease (42.41 +/- 0.85%) and anti-tyrosinase (39.82 +/- 1.16%) activities of tanshinone I were also observed. Potential inhibitory effects of these molecules on target proteins were investigated using DOCK and molecular dynamics calculations. Dock score analysis and Lipinski parameters were demonstrated that these ligands are potential inhibitors against relevant enzymes. Our findings suggest that Salvia species can be utilized as a ptential source of anti-alzheimer active compounds for designing novel products.
- PublicationOpen AccessBioguided Isolation of Secondary Metabolites from Salvia cerino-pruinosa Rech. f. var. cerino-pruinosa(2021-11-01T00:00:00Z) Ertas, Abdulselam; Cakirca, Hatice; Yener, Ismail; Akdeniz, Mehmet; Fırat, Mehmet; TOPÇU, GÜLAÇTI; KOLAK, Ufuk; TOPÇU, GÜLAÇTIIn the current study, the ethanol extracts prepared from the aerial parts and roots of an endemic species, Salvia cerino-pruinosa Rech. f. var. cerino-pruinosa were fractionated on silica gel columns and tested for determination of their antioxidant activity using DPPH free radical and ABTS cation radical scavenging, and cupric reducing antioxidant capacity (CUPRAC) test assays. Twenty known secondary metabolites were isolated from the active antioxidant fractions; rosmarinic acid (1), chlorogenic acid (2), caffeic acid (3), 4-hydroxybenzoic acid (4), benzoic acid (5), luteolin 7-O-glucoside (6), bis-(2-ethylhexyl)benzene-1,2-dicarboxylate (7), salvianolic acid A (8), salvianolic acid B (9), 7-acetylroyleanone (10), 6,7-dehydroroyleanone (11), ferruginol (12), inuroyleanol (13), 12-hydroxy-6,7-secoabieta-8,11,13-triene-6,7-dial (14), ursolic acid (15), oleanolic acid (16), taraxasterol (17), lupenone (18), beta-sitosterol (19), and stigmasterol (20). Rosmarinic acid, which was obtained from the aerial parts, was found to be the best antioxidant compound among the isolated secondary metabolites in DPPH free radical and ABTS cation radical scavenging, and CUPRAC assays (IC50: 1.20 +/- 0.04 mu g/mL, IC50: 1.74 +/- 0.06 mu g/mL, A(0.5): 1.22 +/- 0.02 mu g/mL, respectively). Chlorogenic and caffeic acids, luteolin 7-O-glucoside, salvianolic acids A and B, and inuroyleanol exhibited also high antioxidant activity in the mentioned assays.
- PublicationMetadata onlyPrangos ilanae Bitkisinden Elde Edilen Kumarinlerin Antikoagülan Etkisinin İncelenmesi(2019-03-17) DİNCEL, DEMET; UÇKAYA, FATİH; Özer, Ö.F.; TOPÇU, GÜLAÇTI; DİNCEL, DEMET; UÇKAYA, FATİH; ÖZER, ÖMER FARUK; TOPÇU, GÜLAÇTI
- PublicationMetadata onlyAnticarcinogenic effect of a novel alkaloid: 1H-indole-2-hydroxy, 3-carboxylic acid(2019-09-27T00:00:00Z) ÖZGÜN ACAR, ÖZDEN; KALE, ELİF; GAZİOĞLU, IŞIL; TOPÇU, GÜLAÇTI; ŞEN, ALAATTİN; GAZİOĞLU, IŞIL; TOPÇU, GÜLAÇTI
- PublicationMetadata onlyEndemik Polygonum sivasicum Kit Tan &Yıldız Türünden Farklı Ekstraksiyon Yöntemleriyle Elde Edilen Ekstrelerin Antioksidan Aktivitesi ve LC-MS ile Fenolik Bileşiklerin in vitro Biyoerişilebilirliğinin Belirlenmesi(2022-06-23T00:00:00Z) Erol, Ebru; Doğan, Kübra; Özeren, Dilara; Kızılarslan Hançer, Çağla; Topçu, Gülaçtı; EROL, EBRU; KIZILARSLAN HANÇER, ÇAĞLA; TOPÇU, GÜLAÇTIPolygonaceae familyası, yaklaşık 48 cins ve 1200 tür ile temsil edilmektedir. ÜlkemizdePolygonumtürleri ile yapılan çalışmalar daha çok, Türkiye’de madımak olarak bilinenPolygonum cognatumMeissn. bitkisi üzerinedir1.Bu çalışmada ise endemikPolygonum sivasicumKit Tan &Yıldız(Sivas madımağı) türünün toprak üstü kısmından farklı ekstraksiyon yöntemleriyle elde edilen ekstrelerin antioksidan aktiviteleri metal bağlama ve CUPRAC yöntemleri, antiradikal aktiviteleri ise DPPH serbest radikal giderimi ve ABTS katyon radikali giderimi yöntemleriyle belirlendi.Diyetimizin bir parçası olarak, polifenoller birçok sağlık faydası ile bağırsakta sindirim sürecinden geçerek sindirim yoluyla dolaşıma katılmaktadır.Diyet polifenollerinin, insanlarda mide sağlığı açısından etkilerini anlamak için bu bileşenlerinin vitrobiyoerişilebilirlik çalışması ağız, mide ve bağırsakda sindirime uğratıldı. Sindirim öncesi ve sonrası fenolik bileşik profili LC-MS ile belirlendi, 27 bileşiğin tanımlandığı analizde rutin, hiperosit ve klorojenik asit majör fenolik bileşikler olarak belirlendi.
- PublicationMetadata onlyAntiprotease and Antioxidant Activities of Salvia montbretii.(2015-10-17) Uçakaya, Meryem; UÇKAYA, FATİH; BEKTAY, MUHAMMED YUNUS; TOPÇU, GÜLAÇTI; UÇKAYA, FATİH; BEKTAY, MUHAMMED YUNUS; TOPÇU, GÜLAÇTI
- PublicationMetadata onlyNovel Terpenoids with Potential Anti-Alzheimer Activity from Nepeta obtusicrena(2016-01-01) Yilmaz, ANIL; Boga, Mehmet; Topcu, GÜLAÇTI; YILMAZ, ANIL; TOPÇU, GÜLAÇTIDichloromethane extract of Nepeta obtusicrena Boiss. Et Kotschy Ex Hedge afforded two novel terpenoids, a diterpenoid and a triterpenoid in addition to two known triterpenoids, oleanolic acid and ursolic acid. Purification of the diterpenoid was carried out by HPLC, and its structure was elucidated as 14a-acetoxy-6-oxo-abieta-7-ene, and structure of the triterpenoid was elucidated as 2 alpha, 3 beta, 19 alpha, 24-tetrahydroxy-11-oxo-olean-12-ene. Both of the novel terpenes were obtained from nature for the first time and named as obtusicrenone and nemrutolone, respectively. Anticholinesterase (anti-Alzheimer) and antioxidant activities [DPPH free radical scavenging activity, ABTS cation radical scavenging activity, lipid peroxidation inhibitory activity, CUPRAC (Cupric Reducing Antioxidant Capacity)] of the dichloromethane and methanol extracts and the isolated four terpenoids were investigated. Both of the extracts and the isolated four terpenoids exhibited high anticholinesterase activity, particularly against acetylcholinesterase (AChE) enzyme. None of the samples tested showed high antioxidant activity.
- PublicationOpen AccessLamiaceae Family Plants as a Potential Anticholinesterase Source in the Treatment of Alzheimer’s Disease(2014-02-01) TOPÇU, GÜLAÇTI; KUŞMAN, TUBA; TOPÇU, GÜLAÇTI; KUŞMAN, TUBAAlzheimer’s disease (AD) is one of the most common and progressive neurodegenerative disorders with dementia in the world. The precise causes of AD are not fully understood yet, although several important features of its pathophysiology are well described. Current AD treatment is symptomatic and is mainly, but not exclusively, focused on the inhibition of cholinesterases (ChEs). There are four cholinesterase inhibitors approved by the U.S. Food and Drug Administration (FDA): tacrine, donepezil, rivastigmine, and galantamine. Among them, galantamine is a natural drug, and rivastigmine is a derivative of the natural drug physostigmine. In addition, only an NMDA (N-methyl- D-aspartate) receptor antagonist, memantine, is also approved by the FDA in the treatment of patients with moderate to severe AD. However, none of them provides a satisfactory treatment for Alzheimer’s disease, and studies are still going on to find new potential drugs from both synthetic chemicals and natural sources. In this review, studies on the discovery of new cholinesterase inhibitors from natural sources, particularly from Lamiaceae family plants were evaluated, and a number of terpenoids and phenolics/flavonoids isolated are presented as potential drugs in the treatment of Alzheimer’s disease.