Ayhan Ulubelen

Istanbul University, İstanbul, Istanbul, Turkey

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Publications (156)377.44 Total impact

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    ABSTRACT: The hexane and dichloromethane extracts, obtained by re-extraction of the methanol extract of Salvia fruticosa Mill., afforded 7 diterpenoids (carnosol, carnosic acid, carnosic acid 12-methyl ether, rosmadial, isorosmanol, ferruginol, and manool), 4 triterpenoids (�alpha-amyryltetracosanoate, oleanolic acid, ursolic acid, and erythrodiol), a steroid (3-acetylsitosterol), and a flavone (salvigenin). The galls (apples) of the collected plant were separately extracted with hexane to a�ord fatty acids composed mainly of oleic acid (29%), palmitoleic acid (29%), and stearic acid (23.20%), which exhibited high anticholinesterase activity, particularly against BChE. The essential oil, obtained from the aerial parts of the plant, exhibited high AChE inhibitory activity, consisting of mainly 1,8-cineol (58.89%). The antioxidant activity according to 6 complementary tests and anticholinesterase potential of the methanol extracts and triterpenoids �alpha-amyryltetracosanoate, oleanolic acid, ursolic acid, and sitosterol acetate were also investigated, and methanol extract exhibited the highest antioxidant and anticholinesterase activity, surpassing the other tested extracts and pure compounds
    Full-text · Article · Jul 2013 · Turkish Journal of Chemistry
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    Ayhan Ulubelen · Ufuk Kolak · Mehmet Boğa

    Full-text · Article · Sep 2012 · Records of Natural Products
  • Ayhan Ulubelen · Ufuk Kolak · M. Boǧa
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    ABSTRACT: This paper covers the screening of the secondary plant products to find a cure against cancer which were piled up during the years. In early stages of these studies highly active antitumor glycoproteins were obtained from native Arizona (USA) plants. Later smaller molecules were isolated showing antitumor activity in different test systems. Among these compounds sesquiterpene lactones with an exo-methylene group in the lactone ring, unsaturated diterpenoids and some triterpenoids exhibited activity in vivo and in vitro test systems. A few Colchicum alkaloids showed high activity against murine lymphocytic leukemia (P388). Activity also established in some flavonoidal compounds. Today all around the world research on Natural Products is still going on.
    No preview · Article · Jan 2012 · Records of Natural Products
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    ABSTRACT: Two known quinolizidine alkaloids, lupanine and leontiformidine, were isolated from the tubers of L. leontopetalum subsp. ewersmannii. Lupanine having the highest inhibition of lipid peroxidation at 100 mu g/mL among the tested samples indicated almost the same ABTS cation radical scavenging activity with BHT, alpha-tocopherol and (+)-catechin at the same concentration. Lupanine and the alkaloidal extract showed almost the same butyrylcholinesterase inhibitory activity with galantamine at 200 mu g/mL.
    Full-text · Article · Mar 2011 · Records of Natural Products
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    ABSTRACT: The methanol extract of Plantago major subsp. intermedia (Gilib.) Lange afforded 4 known compounds, namely isomartynoside (1), 10-hydroxymajoroside (2), beta-sitosterol (3), and ursolic acid (4). Their structures were established by spectroscopic methods. After determination of the total phenolic and flavonoid contents of the methanol extract, the antioxidant potentials of the crude extract and isolated compounds 1-4 were determined by beta-carotene bleaching, DPPH free radical and ABTS cation radical scavenging, and cupric reducing antioxidant capacity methods. The methanol extract, rich in phenolic contents, indicated the same DPPH free radical scavenging activity (72% inhibition) as a standard compound, butylated hydroxytoluene, at 100 mu g/mL. Isomartynoside (1), a phenylpropanoid glycoside, showed the best inhibition of lipid peroxidation, ABTS cation radical scavenging activity, and cupric reducing antioxidant capacity among the tested samples. The anticholinesterase effects of the methanol extract and isolated compounds 1-4 were established using the Ellman method. A triterpenic acid, ursolic acid (4), exhibited moderate acetyl- (54.01 +/- 0.82%) and butyryl-cholinesterase (68.74 +/- 0.36%) inhibitory activity at 200 mu g/mL. Isomartynoside (1) was isolated here for the first time from a Plantago species; the antioxidant and anticholinesterase activities of P. major subsp. intermedia and compounds 1-2 were not previously determined.
    Full-text · Article · Feb 2011 · Turkish Journal of Chemistry
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    ABSTRACT: Seven diterpenoid alkaloids: delcosine(1), delsoline(2), gigactonine(3), lycoctonine(4), takaosamine(5), atisine(6) and hetisinone(7) have been isolated from the aerial parts of Consolida regalis subsp. paniculata var. paniculata. The presence of compounds 1,2,5,6 and 7 in this plant has not been previously reported.
    No preview · Article · Jul 2010 · ChemInform
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    ABSTRACT: Two triterpenoids, namely 2α,3α-dihydroxy-24-nor-4(23),12-oleanadien-28-oic acid (1) and ursolic acid (2); 4 flavonoids, namely 5-hydroxy-7,4'-dimethoxyflavone (3), cirsimaritin (4), eupatilin (5), and salvigenin (6); a diterpenoid, namely sclareol (7); and a steroid, namely β -sitosterol (8), were isolated from the aerial parts of Salvia poculata Nab., a Turkish endemic Salvia species. Total phenolic and flavonoid contents of the crude extract were determined as pyrocatechol and quercetin equivalents, respectively. The antioxidant activity of the crude extract and the isolated compounds (2-8) was established using β -carotene bleaching, superoxide anion radical, and ABTS cation radical scavenging activity. In addition, the anticholinesterase activity of the crude extract and the isolated compounds (2-8) against the enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) was determined. The phytochemistry and antioxidant and anticholinesterase activities of S. poculata were investigated for the first time in this study. The crude extract of S. poculata exhibited a significant antioxidant effect as well as butyrylcholinesterase inhibitory activity. Ursolic acid (2) and cirsimaritin (4) possessed high butyrylcholinesterase inhibitory activity.
    No preview · Article · Dec 2009 · Turkish Journal of Chemistry
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    ABSTRACT: The phytochemical and biological studies carried out on Salvia species showed that their extracts and constituents have various biological activities. The aim of this study was the isolation of diterpenoids from the roots of Salvia barrelieri Ettling and the determination of the antioxidant activity. Chromatographic methods were used for fractionation and isolation, respectively. Structure elucidation was established by spectroscopic methods. Five antioxidant assays were performed. Three new abietane diterpenoids barreliol, royleanone 12-methyl ether and 7-epi-salviviridinol, and six known diterpenoids, with a known dammarane triterpenoid, pyxinol were isolated. The absolute stereochemistry of pyxinol was confirmed by X-ray analysis. Taxodione exhibited the highest antioxidant activity among the tested compounds.
    Full-text · Article · Jul 2009 · Phytochemical Analysis
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    ABSTRACT: The essential oil from the aerial parts of Stachys cretica L. subsp. smyrnaea Rech. fil. (Lamiaceae), endemic to Turkey, was investigated by using GC and GC-MS. Thirty-four of 37 components, represented 99.7% of the total oil, were identified. The major components of the essential oil were trans-beta-caryophyllene (51.0%), germacrene-D (32.8%), a-humulene (3.1%), delta-cadinene (2.1%) and delta-elemene (2.1%). The antimicrobial activity of the essential oil, trans-beta-caryophyllene and five different extracts of the aerial parts of S. cretica L. subsp. smyrnaea were investigated by the standard disc diffusion method. The essential oil and trans-beta-caryophyllene exhibited antibacterial and antifungal activities. The activity increased with increasing concentrations of the essential oil and the extracts. The essential oil showed antimicrobial activity, particularly against Pseudomonas aeruginosa and Bacillus subtilis. The extracts exhibited either moderate or no activity.
    Full-text · Article · Feb 2009 · Natural product communications
  • Ayhan Ulubelen · Ufak Kolak
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    ABSTRACT: Recently, we have investigated Aconitum cochleare Woroschin and obtained three new alkaloids cochleareine, acoleareine from the aerial parts of the plant and cochleareinine from the roots. Cochlearenine exhibited antioxidant activity against DPPH free radical scavenging assay. The cardio active effect of has also have been studied on isolated heart preparations. Two new norditerpene alkaloids linearilobin and linearilin were isolated from Delphinium linearilobum (Trautv.) N. Busch. The antioxidant activity was established by using DPPH and metal chelating activity tests.
    No preview · Article · Jan 2009
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    ABSTRACT: Two triterpenoids, namely 2 α ,3 α -dihydroxy-24-nor-4(23),12-oleanadien-28-oic acid (1) and ursolic acid (2); 4 flavonoids, namely 5-hydroxy-7,4'-dimethoxyflavone (3), cirsimaritin (4), eupatilin (5), and salvigenin (6); a diterpenoid, namely sclareol (7); and a steroid, namely β -sitosterol (8), were isolated from the aerial parts of Salvia poculata Nab., a Turkish endemic Salvia species. Total phenolic and flavonoid contents of the crude extract were determined as pyrocatechol and quercetin equivalents, respectively. The antioxidant activity of the crude extract and the isolated compounds (2-8) was established using β -carotene bleaching, superoxide anion radical, and ABTS cation radical scavenging activity. In addition, the anticholinesterase activity of the crude extract and the isolated compounds (2-8) against the enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) was determined. The phytochemistry and antioxidant and anticholinesterase activities of S. poculata were investigated for the first time in this study. The crude extract of S. poculata exhibited a significant antioxidant effect as well as butyrylcholinesterase inhibitory activity. Ursolic acid (2) and cirsimaritin (4) possessed high butyrylcholinesterase inhibitory activity.
    Full-text · Article · Jan 2009
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    ABSTRACT: Ten diterpenoids [6a-hydroxysalvinolone (1), 6a-hydroxytaxodone (2), aethiopinone (3), microstegiol (4), ferruginol (5), saprorthoquinone (6), 11,12-dioxoabieta-8,13-diene (7), taxodione (8), hypargenin A (9), hypargenin D (10)] and three triterpenoids [lupeol 3-acetate, d-oleanol 3-acetate and ß-sitosterol] were isolated from the roots of Salvia hypargeia, a plant endemic to Turkey. The crude extract and compounds 1-2, 5-10 were tested against a panel of human cancer cell lines [human breast cancer (BC 1), human lung cancer (LU 2), human colon cancer (COL 2), human epidermoidal carcinoma in mouth (KB), vinblastine-resistant KB-VI, hormone-dependent human prostate cancer (LNCaP)] as well as P388 and ASK cells in culture. The crude extract was active in all of the test systems, except KB. Isolates 1 and 8 were also found to mediate a generalized cytotoxic response.
    No preview · Article · Sep 2008 · Pharmaceutical Biology
  • Gulacti Topcu · Ayhan Ulubelen
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    ABSTRACT: In our continuing studies on Lamiaceae family plants including Salvia, Teucrium, Ajuga, Sideritis, Nepeta and Lavandula growing in Anatolia, many terpenoids, consisting of over 50 distinct triterpenoids and steroids, and over 200 diterpenoids, several sesterterpenoids and sesquiterpenoids along with many flavonoids and other phenolic compounds have been isolated. For Salvia species abietanes, for Teucrium and Ajuga species neo-clerodanes for Sideritis species ent-kaurane diterpenes are characteristic while nepetalactones are specific for Nepeta species. In this review article, only some interesting and different type of skeleton having constituents, namely rearranged, nor- or rare diterpenes, isolated from these species will be presented. For structure elucidation of these natural diterpenoids intensive one- and two-dimensional NMR techniques (1H, 13C, APT, DEPT, NOE/NOESY, 1H–1H COSY, HETCOR, COLOC, HMQC/HSQC, HMBC, SINEPT) were used besides mass and some other spectroscopic methods.
    No preview · Article · Aug 2007 · ChemInform
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    ABSTRACT: The methanol extract of Salvia macrochlamys Boiss. and Kotschy was fractionated on a silica gel column to yield a group of terpenic compounds. After separation and cleaning, seven known and three new terpenoid compounds were isolated, and their structures were elucidated by spectroscopic methods, including intensive NMR and MS studies. The crude extract was tested in five different systems for antioxidant activity. The extract and monogynol A (1) and its three derivatives (2-4) were found to be highly active in a metal chelating test system on ferrous ions.
    Full-text · Article · Feb 2007
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    ABSTRACT: Acetone and methanol extracts of the fruits of Pistacia terebinthus L. subsp. terebinthus L. were studied for their antioxidant activity by investigating their total phenolic and flavonoid contents, β-carotene bleaching potential, DPPH radical scavenging effect, scavenging activity on superoxide anion radical, reducing power, and metal chelating effect on ferrous ion. Both extracts showed very similar chemical profile by checking on TLC plates, and exhibited high scavenging activity on superoxide anion radical and DPPH radical. Due to these similarities they were combined and fractionated on a silica gel column for their constituents, and the most active three fractions in DPPH assay were purified to afford a new flavone 6′-hydroxyhypolaetin 3′-methyl ether (1) besides a group of known flavonoids apigenin, luteolin, luteolin 7-O-glucoside, quercetin, quercetagetin 3-methyl ether 7-O-glucoside, isoscutellarein 8-O-glucoside. Their structures were established by UV, UV shift reagents, and 1H NMR spectroscopic techniques. Antioxidant activity of the new flavone was investigated by β-carotene bleaching and DPPH radical scavenging activity methods, and it showed a high activity in the first system, but not so good in the latter.
    Full-text · Article · Jan 2007 · Food Chemistry
  • Gulacti Topcu · Ufuk Kolak · Kubilay Balci · Ayhan Ulubelen
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    ABSTRACT: A new rearranged abietane diterpenoid, eriophoroxide (1), was obtained from the root extract of Salvia eriophora Boiss. and Kotschy ex Boiss. Its structure was elucidated by spectroscopic methods and semi-empirical/ab-initio calculations. DNA damaging, cytotoxic and antioxidant activities of the plant extract were tested.
    No preview · Article · Jan 2007 · Natural product communications
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    Ufuk Kolak · Mehmet Oztürk · Fevzi Ozgökçe · Ayhan Ulubelen
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    ABSTRACT: From the roots of Delphinium linearilobum (Trautv.) N. Busch two new norditerpene alkaloids linearilobin and linearilin, and the known alkaloids lycoctonine, 14-acetyltalatizamine, browniine, cammaconine, talatizamine, and cochlearenine were isolated. Spectroscopic techniques were used for structure determination. Antioxidant activity was performed by DPPH and metal chelating activity assays.
    Full-text · Article · Nov 2006 · Phytochemistry
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    Ufuk Kolak · Mehmet Öztürk · Fevzi Özgökçe · Ayhan Ulubelen

    Full-text · Article · Feb 2006
  • Ayhan Ulubelen · Mehmet Oeztuerk
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    ABSTRACT: Although there are a number of Ruta species in the world, R. graveolens L., R. chalepensis L., R. montana (L.) L., R. angustifolia Pers. and R. pinnata L. fil. are the most studied. However, the first two of them have been the most extensively investigated for their chemical constituents and biological activities. They are used for their anthelmintic, diuretic, emmenagogue, and aphrodisiac properties. In dermatology, they are used against psoriasis and vitiligo, and as mycosis fungicides. In many countries, the plant extracts have been used as birth control agents.
    No preview · Article · Jan 2006 · Natural product communications
  • Ayhan Ulubelen · Gulacti Topcu · Ufuk Kolak
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    ABSTRACT: There are about 200 genera in Labiatae family in the world, whereas in Turkish flora 45 genera are present. A literature survey revealed that only 10 genera are extensively investigated for the flavonoidal compounds, some work were done about 23 genera, but the rest had no flavonoidal investigation. The biological activities of flavonoids were also studied together with their structural studies. The most studied genus for the biological activities is Scutellaria. Baicalein, baicalin and wogonin showed a number of important activities.
    No preview · Article · Dec 2005 · Studies in Natural Products Chemistry

Publication Stats

2k Citations
377.44 Total Impact Points

Institutions

  • 1973-2013
    • Istanbul University
      • • Department of Analytical Chemistry
      • • Department of Pharmacognosy
      • • Department of Chemistry
      İstanbul, Istanbul, Turkey
  • 2001
    • Athens State University
      Athens, Alabama, United States
  • 1998
    • University of Peshawar
      Peshawar, Khyber Pakhtunkhwa, Pakistan
  • 1997-1998
    • TUBITAK Marmara Research Center
      Marmara, Balıkesir, Turkey
    • Ankara University
      • Faculty of Pharmacy
      Engüri, Ankara, Turkey
  • 1995
    • Texas Christian University
      • Department of Chemistry
      Fort Worth, Texas, United States
    • Universidad de La Laguna
      San Cristóbal de La Laguna, Canary Islands, Spain
  • 1994
    • University of Illinois at Chicago
      • Department of Medicinal Chemistry and Pharmacognosy
      Chicago, Illinois, United States
  • 1988
    • Marmara University
      İstanbul, Istanbul, Turkey
  • 1980-1984
    • University of Texas at Austin
      • Department of Botany
      Austin, Texas, United States