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TOPÇU, GÜLAÇTI

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Eczacılık Fakültesi

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GÜLAÇTI

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TOPÇU

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Now showing 1 - 10 of 17

Open Access
Triterpenoids and steroids isolated from Anatolian Capparis ovata and their activity on the expression of inflammatory cytokines
(2020-01-01T00:00:00Z) GAZİOĞLU, IŞIL; Semen, Sevcan; Acar, Ozden Ozgun; KOLAK, Ufuk; Sen, Alaattin; TOPÇU, GÜLAÇTI; GAZİOĞLU, IŞIL; TOPÇU, GÜLAÇTI
Context: Capparis L. (Capparaceae) is grown worldwide. Caper has been used in traditional medicine to treat various diseases including rheumatism, kidney, liver, stomach, as well as headache and toothache. Objective: To isolate and elucidate of the secondary metabolites of the C. ovata extracts which are responsible for their anti-inflammatory activities. Materials and methods: Buds, fruits, flowers, leaves and stems of C. ovata Desf. was dried, cut to pieces, then ground separately. From their dichloromethane/hexane (1:1) extracts, eight compounds were isolated and their structures were elucidated by NMR, mass spectroscopic techniques. The effects of compounds on the expression of inflammatory cytokines in SH-SY5Y cell lines were examined by qRT-PCR ranging from 4 to 96 mM. Cell viability was expressed as a percentage of the control, untreated cells. Results: This is a first report on isolation of triterpenoids and steroids from C. ovata with anti-inflammatory activity. One new triterpenoid ester olean-12-en-3b,28-diol, 3b-pentacosanoate (1) and two new natural steroids 5a,6a-epoxycholestan-3b-ol (5) and 5b,6b-epoxycholestan-3b-ol (6) were elucidated besides known compounds; oleanolic acid (2), ursolic acid (3), b-sitosterol (4), stigmast-5,22-dien-3b-myristate (7) and bismethyl-octylphthalate (8). mRNA expression levels as EC10 of all the tested seven genes were decreased, particularly CXCL9 (19.36-fold), CXCL10 (8.14-fold), and TNF (18.69) by the treatment of 26 mM of compound 1 on SH-SY5Y cells. Discussion and conclusions: Triterpenoids and steroids isolated from C. ovata were found to be moderate-strong anti-inflammatory compounds. Particularly, compounds 1 and 3 were found to be promising therapeutic agents in the treatment of inflammatory and autoimmune diseases.
Open Access
Synthesis and Characterization of Biodegradable Amphiphilic Star and Y-Shaped Block Copolymers as Potential Carriers for Vinorelbine
(2014-01-01T00:00:00Z) Bahadori, Fatemeh; Dag, Aydan; Durmaz, Hakan; Cakir, Nese; ONYUKSEL, Hayat; Tunca, Ümit; Topcu, Gulacti; Hızal, Gürkan; BAHADORİ, FATEMEH; DAĞ, AYDAN; TOPÇU, GÜLAÇTI
Two amphiphilic block copolymers using hydrophobic poly(e-caprolactone) (PCL) and hydrophilic poly(ethylene glycol) (PEG) were successfully synthesized. One of them is an (A-b-B)(4) type star polymer [(PCL-b-PEG)(4)] and the other one is a Y-shaped PEG-(PCL)(2). A star-shaped polymer (PCL-b-PEG)(4) was prepared by ring-opening polymerization (ROP) of epsilon-caprolactone continued by click reaction of (PCL-azide)(4) and PEG-alkyne. The synthesis of Y-shaped PEG-(PCL)(2) block copolymer was carried out via Diels-Alder click reaction of a furan protected maleimide end-functionalized PEG (PEG-MI) with an anthracene end-functionalized PCL following the ROP of epsilon-caprolactone. The characterization of micelles is carried out using both materials in aqueous media as drug delivery vehicles, which showed satisfying results and enhanced the cytotoxic effect of the anti-cancer drug vinorelbine (VLB). However, micelles consisted of Y-shaped unimers were found to be more convenient for delivery of hydrophobic drugs such as VLB because they formed in lower concentration, carrying a higher amount of drugs and owing a monomodal distribution. We concluded that the free tails of hydrophobic chains in Y-shaped block copolymer facilitate the assembly of amphiphilic material in water to form micelles.
Open Access
Special issue dedicated to the memory of Professor Ayhan Ulubelen (1931-2020)
(2021-01-01T00:00:00Z) TOPÇU, GÜLAÇTI; TOPÇU, GÜLAÇTI
Open Access
Antioxidant and toxicological in-vivo and in-vitro examination of licorice extract
(2016-09-01) Bektay, MUHAMMED YUNUS; Uckaya, FATİH; Guler, E. M.; Bayindir, NİHAN; Kocyigit, ABDÜRRAHİM; Esrefoglu, MUKADDES; Topcu, GÜLAÇTI; BEKTAY, MUHAMMED YUNUS; UÇKAYA, FATİH; GÜLER, ERAY METİN; BAYINDIR, NİHAN; KOÇYİĞİT, ABDÜRRAHİM; EŞREFOĞLU, MUKADDES; TOPÇU, GÜLAÇTI
Open Access
Bioguided 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, GÜLAÇTI
In 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.
Open Access
Anticholinesterase furocoumarins from Heracleum platytaenium, a species endemic species to Ida Mountains
(2013-01-01) Dincel, DEMET; Hatipoglu, Seda Damla; GOREN, AHMET CEYHAN; Topcu, Gulacti; DİNCEL, DEMET; GÖREN, AHMET CEYHAN; TOPÇU, GÜLAÇTI
The petroleum ether extract of Heracleum platytaenium afforded 8 furocoumarins (psoralen, bergapten, xanthotoxin, pimpinellin, isopimpinellin, sphondin, byakangelicin, and heraclenol) and the methanol extract of H. platytaenium gave only 1 glycosylated dihydrofurocoumarin, apterin. In addition, stigmasterol was also obtained from petroleum ether extract. Structure identification of the isolated compounds has been achieved by using spectroscopic methods, namely 1D and 2D NMR experiments and mass spectral analyses. The antioxidant activity of the extracts and pure compounds was investigated by 2 methods, including DPPH free radical scavenging activity and lipid peroxidation inhibitory activity by beta-carotene-linoleic acid assays. The anticholinesterase activity of petroleum ether and methanol extracts of the plant and the isolated furocoumarins was investigated against acetylcholinesterase and butyrylcholinesterase enzymes by the Ellman method in vitro.
Open Access
Cytotoxic, Apoptotic and Genotoxic Effects of Lipid-Based and Polymeric Nano Micelles, an In Vitro Evaluation
(2017-11-01) BAHADORİ, FATEMEH; KOÇYİĞİT, ABDÜRRAHİM; DAĞ, AYDAN; TOPÇU, GÜLAÇTI; BAHADORİ, FATEMEH; KOÇYİĞİT, ABDÜRRAHİM; DAĞ, AYDAN; TOPÇU, GÜLAÇTI
Self-assembly systems (SAS) mainly consist of micelles, and liposomes are the classes of Nano Drug Delivery Systems with superior properties compared to traditional therapeutics in targeting cancer tumors. All commercially available nano-formulations of chemotherapeutics currently consist of SAS. According to our knowledge, a specific toxicity comparison based on material differences has not yet been performed. The purpose of this study was to evaluate and compare the toxicity of two SAS consisting of Sterically Stabilized Micelles (SSM) made of a lipid-based amphiphilic distearoyl-sn-glycero-phosphatidylethanolamine-polyethylene glycol (PEG)-2000 and a polymeric micelle (PM) consisting of Y-shape amphiphilic block copolymer, synthesized using poly ε-caprolactone and PEG. The mechanism of cytotoxicity and genotoxicity of micelles on L-929 healthy mouse fibroblast cells was assessed using Sulforhodamine-B, WST-1, Acridine Orange/Ethidium Bromide and alkaline single-cell gel electrophoresis assays. Results showed that SSM in conc. of 40 mg/mL shows very low cytotoxicity at the end of 24, 48 and 72 h. The DNA damage caused by SSM was much lower than PM while the latter one showed significant toxicity by causing apoptosis with the ED50 value of 3 mg/mL. While the DNA damage caused by SSM was ignorable, some DNA chain breaks were detected on cells treated with PM.
Open Access
Isoquinoline alkaloids isolated from Glaucium corniculatum var. corniculatum and Glaucium grandiflorum subsp. refractum var. torquatum with bioactivity studies
(2023-06-01) Kuşman Sayğı T.; Tan N.; Alim Toraman G. Ö.; Gürer Ç.; Tugay O.; Topçu G.; ALİM TORAMAN, GÜLBAHAR ÖZGE; TOPÇU, GÜLAÇTI
Context: The genus Glaucium Mill., one of the important Papaveraceae family plants, is rich in isoquinoline alkaloids and distributed worldwide. Objective: Isolation and identification of bioactive alkaloids from Glaucium grandiflorum Boiss. & Huet. subsp. refractum (Nabelek) Mory var. torquatum (Cullen) Mory and G. corniculatum (L.) Rudolph var. corniculatum (Aslan 2012), and investigation of their antioxidant and anticholinesterase activities. Materials and methods: The aerial parts of each plant were dried, powdered, and percolated with methanol, then each extract was fractionated between 50% aqueous acetic acid and petroleum. Their aqueous acidic layer was adjusted to pH 7-8 with NH4OH and extracted with chloroform, the extract was subjected to CC separation and isolation. Structures of the isolated alkaloids were elucidated by 1D and 2D-NMR and mass spectral analyses. The alkaloid extracts and their pure alkaloids were tested for anti-cholinesterase (AChE and BuChE) and antioxidant (ABTS, CUPRAC, β-carotene linoleic acid tests) activities in vitro. Results: Methanol extracts of Glaucium grandiflorum subsp. refractum var. torquatum and G. corniculatum var. corniculatum afforded a novel compound glauciumoline and seven known isoquinoline alkaloids three of which have an aporphine-type and the other five have a protopine-type skeleton. Among them, trans-protopinium (7) and cis-protopinium (8) were isolated from a Glaucium species for the first time. Tertiary amine extracts (TAEs) of both plants showed very strong acetylcholinesterase inhibitory activity. The TAE of the plants also showed strong antioxidant activity while the isolated alkaloids showed no meaningful activity in the anticholinesterase and antioxidant tests. Discussion and conclusions: Glaucium species are considered promising therapeutic agents in the treatment of Alzheimer's disease.
Open Access
SAR Evaluation of Disubstituted Tacrine Analogues as Promising Cholinesterase and Carbonic Anhydrase Inhibitors
(2019-04-01) ÖKTEN, S; EKIZ, M; TUTAR, A; BÜTÜN, BURCU; Gülçin, İlhami; TOPÇU, GÜLAÇTI; BÜTÜN, BURCU; TOPÇU, GÜLAÇTI
Background: The inhibition of both hydrolysis products of acetylcholine (ACh), Acetylcholinesterase (AChE) and Butyrylcholinesterase (BChE), is essential for successful treatment of Alzhemier patients. Objectives: This study was investigated inhibition potentials of recently synthesized disubstituted tacrines derivatives on going our research against AChE, BChE and carbonic anhydrase cyctosolic (hCA I and H) enzymes to explore the Structure activity relationship (SAR). Methods: Inhibitory activities of tested compounds against AChE and BChE were measured by spectrophotometric method, developed by Ellman et al. Furthermore, the disubstituted tacrines were determined as inhibitors of two physiologically relevant CA isoforms, the cytosolic hCA I and H by an esterase assay method. Results: The silyl, thiomethyl and cyano substituted seven membered hydrocycle tacrines (9, 11 and 14) significantly inhibited AChE, compared with starting compound 3 (6,8-dibromo-2,3,4,5-teytrahydro-1H-cyclohepta[1,2-b] quinoline) and reference compounds, galantamine and tacrine, while methoxy substituted seven membered hydrocycle tacrine derivative 10 showed selective inhibition against BChE (IC50 = 563 nM). Interestingly, disubstituted tacrines displayed higher or parallel inhibition to galantamine. Additionally, all these tacrine analogues were recorded to be powerful inhibitor compounds of the cytosolic isoenzyme hCA I with K-i in the range of 43.81-471.67 nM, as well as a moderate selectivity toward hCA II isoenzyme with K-i in the range from 87.14 to 614.68 nM compared with AZA, as standard. Conclusion: The disubstituted seven membered hydrocycle tacrine analogues 9-12 and 14 may have promising anti Alzhemier drug candidate and dibromo six membered hydrocycle 2 and dibromo seven membered hydrocycle 3 derivatives may be novel hCA I and II enzyme inhibitors.
Open Access
Flavonoid constituents of Sideritis caesarea
(2013-01-01) Halfon, Belkis; Ciftci, Ece; Topcu, GÜLAÇTI; TOPÇU, GÜLAÇTI
The acetone extract of the aerial parts of Sideritis caesarea Duman, Aytac & Baser (Lamiaceae) afforded the flavonoids penduletin (1) and apigenin (2) and 6 glycosylated flavonoids, 4--O-methyl-isoscutellarein-7-O-[6 --O-acetyl-beta-D-allopyranosyl-(1 -> 2)]-6 --O-acetyl-beta-D-glucopyranoside (3), 4--O-methylhypolaetin-7-O-[6 --O-acetyl-beta-D-allopyranosyl-(1 -> 2)]-6 --O-acetyl-beta-D-glucopyranoside (4), isoscutellarein-7-O-[6 --O-acetyl-beta-D-allopyranosyl-(1 -> 2)]-6 --O-acetyl-beta-D-glucopyranoside (5), isoscutellarein-7-O-[6 --O-acetyl-beta-D-allopyranosyl-(1 -> 2)]-beta-D-glucopyranoside (6), 4--O-methylhypolaetin-7-O-[6 --O-acetyl-beta-D-allopyranosyl-(1 -> 2)]-beta-D-glucopyranoside (7), and hypolaetin-7-O-[6 --O-acetyl-beta-D-allopyranosyl-(1 -> 2)]-beta-D-glucopyranoside (8). The compounds were identified by the use of 1D- and 2D-NMR and UV spectroscopic techniques and by comparisons with the reported data. The acetyl-cholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of the acetone, methanol, and water extracts of the plant and of the flavones penduletin and apigenin were evaluated at 200 mu g/mL. The water extract exhibited better activity against the enzyme AChE as compared to both the acetone and the methanol extracts. Penduletin (1) showed significant activity against BChE (66.58%) while apigenin (2) showed weak activity against both enzymes.