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Öğe Antimicrobial and antimalarial activities of some endemic Turkish Verbascum species(2004) Akdemir Z.Ş.; Tatli I.I.; Bedir E.; Khan I.A.The antimicrobial activities of ethyl acetate and methanol extracts of five Verbascum species were studied. The dried extracts of the aerial parts of Verbascum chionophyllum Hub.-Mor., V. cilicicum Boiss., V. pterocalycinum var. mutense Hub.-Mor., V. pycnostachyum Boiss. & Helder. and V. splendidum Boiss. were tested in vitro against Candida albicans (ATCC 90028), Cryptococcus neoformans (ATCC 90113), Staphylococcus aureus (ATCC 29213), methicillin-resistant S. aureus (ATCC 43300), Pseudomonas aeruginosa (ATCC 27853), Aspergillus fumigatus (ATCC 90906) and Mycobacterium intracellulare (ATCC 23068) using a 96-well microplate assay. Amphotericin B, ciprofloxacin and rifampin were used as positive controls. The antimalarial activities of the same extracts were also tested to Plasmodium falciparum clone [Sierra Leone D6 (chloroquine-sensitive)]. The antimalarial agents chloroquine and artemisinin were used as positive controls. None of the tested extracts showed important antimicrobial or antimalarial activities.Öğe Antioxidant flavonoids from Verbascum salviifolium boiss(2004) Akdemir Z.S.; Tatli I.I.; Bedir E.; Khan I.A.Phenolic natural products such as flavonoids are known as potential antioxidant compounds. The aim of this study was the isolation, structure elucidation and determination of radical scavenging properties of flavonoids which were guided by DPPH autographic assay from the methanolic extract of the aerial parts of Verbascum salviifolium. From the titled plant, four flavonoid glucosides, apigenin-7-O-ß-glucopyranoside (1), luteolin-7-O-ß- glucopyranoside (2), luteolin-3'-O-ß-glucopyranoside (3), and chrysoeriol-7-O-ß-glucopyranoside (4), were isolated. The structures of the compounds were established on the basis of the spectroscopic evidence. Compounds 1-4 demonstrated scavenging properties toward the 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical in TLC autographic assays.Öğe Antioxidant lignans from Larrea tridentata(2004) Abou-Gazar H.; Bedir E.; Takamatsu S.; Ferreira D.; Khan I.A.Three lignans, (7S,8S,7'S,8'S)-3,3',4'-trihydroxy- 4-methoxy-7,7'-epoxylignan and meso-(rel 7S,8S,7'S,8'S)-3,4, 3',4'-tetrahydroxy-7,7'-epoxylignan with significant antioxidant properties, and (E)-4,4'-dihydroxy-7,7'-dioxolign- 8(8')-ene, were isolated from the leaves of Larrea tridentata. The structures of the new compounds were determined primarily from 1D and 2D NMR analysis. Their antioxidant activities were evaluated on intracellular reactive oxygen species in HL-60 cells. Three lignans, (7S,8S,7'S,8'S)-3, 3',4'-trihydroxy-4-methoxy-7,7'-epoxylignan, meso-(rel 7S,8S,7'R,8'R)-3,4,3',4'-tetrahydroxy-7, 7'-epoxylignan, and (E)-4,4'-dihydroxy-7,7'-dioxolign- 8(8')-ene, together with 10 known compounds, were isolated from the leaves of Larrea tridentata. The structures of the new compounds were determined primarily from 1D and 2D NMR spectroscopic analysis. Their antioxidant activities against intracellular reactive oxygen species were evaluated in HL-60 cells. © 2004 Published by Elsevier Ltd.Öğe Bioactive constituents from Turkish Pimpinella species(2005) Tabanca N.; Bedir E.; Ferreira D.; Slade D.; Wedge D.E.; Jacob M.R.; Khan S.I.; Kirimer N.; Can Baser K.H.; Khan I.A.A new 'phenylpropanoid', 4-(3-methyloxiran-2-yl)phenyl 2-methylbutanoate (1), a new trinorsesquiterpene, 4-(6-methylbicyclo[4.1.0]hept-2-en-7-yl)butan-2-one (2), and eight known compounds (3-10) were isolated from the essential oils of several Pimpinella species growing in Turkey. The structures of the new compounds were determined by 1D- and 2D-NMR analyses. The absolute configuration of 1 was established via comparison of its optical rotation with that of 'epoxypseudoisoeugenyl 2-methylbutyrate' (11), the absolute configuration of which was determined by chemical degradation and an appropriate Mosher ester formation. Direct bioautography revealed antifungal activity of 1 and 11 against Colletotrichum acutatum, C. fragariae, and C. gloesporioides. Subsequent evaluation of antifungal compounds in a 96-well microtiter assay showed that compounds 1 and 11 produced the most-significant growth inhibition in Phomopsis spp., Colletotrichum spp., and Botrytis cinerea. Compounds 1 and 6 displayed antimicrobial activities against Mycobacterium intracellulare, with IC50 values of 2.78 and 1.29 µM, respectively. © 2005 Verlag Helvetica Chimica Acta AG, Zürich.Öğe Cycloartane-type glycosides from Astragalus schottianus(2012) Karabey F.; Khan I.A.; Bedir E.Three new cycloartane-type triterpene glycosides were isolated from the roots of Astragalus schottianus Boiss. Their structures were established as 20(R),25-epoxy-3-O-ß-d-xylopyranosyl-24-O-ß-d-glucopyranosyl-3ß, 6?,16ß,24?-tetrahydroxycycloartane (1), 20(R),25-epoxy-3-O- [ß-d-glucopyranosyl(1 › 2)]-ß-d-xylopyranosyl-24-O-ß-d- glucopyranosyl-3ß,6?,16ß,24?-tetrahydroxycycloartane (2), 3-O-ß-d-xylopyranosyl-3ß,6?,16ß,20(S),24(S), 25-hexahydroxycycloartane (3) by the extensive use of 1D and 2D-NMR techniques and mass spectrometry. © 2012 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.Öğe Effect of different levels of nitrogen on dry matter and grain yield of faba bean (Vicia Faba L.)(2008) Daur I.; Sepetoglu H.; Marwat K.B.; Hassan G.; Khan I.A.Faba bean is widely used in the Mediterranean region as source of protein in both human and animal nutrition. A legume member so fixes atmospheric nitrogen but with the assumption that nitrogen application to crops often results in yield improvement, a field experiment with N rates was conducted for two consecutive years. In the experiment 12 faba bean genotypes (KITIKI-2003, ERESEN-87, FİLİZ-99, SEVİL, SAKIZ, 95 ETA 225, 95 ETA 249, 95 ETA 276, 97 ETA 718, 97 ETA 727, 98 ETA 296 and 98 ETA 329) at 5 N rates (0, 50, 100, 150, and 200 kg ha-1) were evaluated for dry matter production and grain yield. Genotypes showed significant variation in grain yield and shoot dry weight. Genotype FİL·Z-99 was the highest yielding, whereas genotype SEVİL was the lowest yielding and the remaining genotypes were intermediate in grain yielding potential. Grain yield and shoot dry weight indicated significant quadratic relation with the increasing N rates between 0 and 200 kg ha.Öğe Effect of essential oils and isolated compounds from Pimpinella species on NF-?B: A target for antiinflammatory therapy(2007) Tabanca N.; Ma G.; Pasco D.S.; Bedir E.; Kirimer N.; Baser K.H.C.; Khan I.A.; Khan S.I.Pimpinella essential oils and isolated compounds were screened for their inhibitory activity against NF-?B mediated transcription in SW1353 cells. Twelve oils were effective in inhibiting NF-?B mediated transcription. Especially the roots of P. corymbosa, P. tragium and P. rhodanta showed potent activities with IC50 values of 2, 3 and 6 µg/mL, respectively. Five pure compounds, 7 (4-(2-propenyl)phenylangelate), 12 (4-(3-methyloxiranyl) phenyltiglate), 17 (4-methoxy-2-(3-methyloxiranyl)phenyl isobutyrate), 18 (4-methoxy-2-(3-methyloxiranyl)phenylangelate) and 21 (epoxy pseudoisoeugenol-2-methylbutyrate) inhibited NF-?B mediated transcription with IC50 values of 5.5, 1.2, 0.01, 3.6 and 11 µg/mL, respectively. None of the compounds were cytotoxic to mammalian cells. These findings add significant information to the pharmacological activity of Pimpinella species and their beneficial effects and use in disease prevention especially those related to inflammation. Copyright © 2007 John Wiley & Sons, Ltd.Öğe Estrogenic activity of isolated compounds and essential oils of Pimpinella species from Turkey, evaluated using a recombinant yeast screen(2004) Tabanca N.; Khan S.I.; Bedir E.; Annavarapu S.; Willett K.; Khan I.A.; Kirimer N.; Baser K.H.C.Several plants and plant-derived pure compounds, designated as phytoestrogens, have been reported to cause estrogenic effects. They have been used for alleviation of menopausal symptoms, prevention of osteoporosis, heart disease and cancer. There is an increased interest in studying phytoestrogens such as isoflavones and lignans for their use as replacements for synthetic estrogens. In this study, the estrogenic activity of essential oils of eleven Pimpinella species and the compounds isolated from these species were evaluated using the yeast estrogen screen (YES) assay. The essential oils containing (E)-anethole as major compound showed estrogenic activity in the YES assay, except for the aerial parts without fruits of P. anisetum and P. flabellifolia. The percent maximal response produced by most anethole-containing oils was 30-50%. Fruits of P. isaurica and P. peucedanifolia were estrogenic in spite of the absence or trace amount of anethole, respectively. This study indicates that the estrogenic activity of Pimpinella oils is not solely due to the presence of anethole. Components other than anethole may be responsible for contributing towards the estrogenic activity. The essential oils from different species varied in their estrogenic potencies (relative potency from 8.3 × 10 -8 to 1.2 × 10-6 compared to 17ß-estradiol) and among the different plant parts, the fruit oils of most species were estrogenic followed by the aerial parts without fruits and the root oils and their EC 50 values varied from 45 µg/mL to 650 µg/mL.Öğe Inhibition of human cytochromes P450 by components of Ginkgo biloba(2004) von Moltke L.L.; Weemhoff J.L.; Bedir E.; Khan I.A.; Harmatz J.S.; Goldman P.; Greenblatt D.J.The extraction, isolation and characterization of 29 natural products contained in Ginkgo biloba have been described, which we have now tested for their in-vitro capacity to inhibit the five major human cytochrome P450 (CYP) isoforms in human liver microsomes. Weak or negligible inhibitory activity was found for the terpene trilactones (ginkgolides A, B, C and J, and bilobalide), and the flavonol glycosides. However 50% inhibitory activity (IC50) was found at concentrations less than 10 µg mL-1 for the flavonol aglycones (kaempferol, quercetin, apigenin, myricetin, tamarixetin) with CYP1A2 and CYP3A. Quercetin, the biflavone amentoflavone, sesamin, as well as Z,Z)-4,4'-(1,4-pentadiene-1,5-diyl)diphenol and 3-nonadec-8-enyl-benzene-1,2-diol, were also inhibitors of CYP2C9. The IC50 of amentoflavone for CYP2C9 was 0,019 µg mL-1 (0.035 µM). Thus, the principal components of Ginkgo biloba preparations in clinical use (terpene trilactones and flavonol glycosides) do not significantly inhibit these human CYPs in-vitro. However, flavonol aglycones, the biflavonol amentoflavone and several other non-glycosidic constituents are significant in-vitro inhibitors of CYP. The clinical importance of these potential inhibitors will depend on their amounts in ginkgo preparations sold to the public, and the extent to which their bioavailability allows them to reach the CYP enzymes in-situ. © 2004 The Authors.Öğe Lotaustralin from Rhodiola rosea roots(2004) Akgul Y.; Ferreira D.; Abourashed E.A.; Khan I.A.Lotaustralin was isolated as a mixture of two diastereoisomeric forms from the methanol extract of Rhodiola rosea roots, together with the known compounds rosavin, rosarin, rosin, rosiridin, salidroside, and ß-sitosterol. The structure of lotaustralin was established by 1D and 2D-NMR spectroscopy, including 1H- 1H COSY, NOESY, HMQC, and HMBC, and FAB and HR MS. © 2004 Elsevier B.V. All rights reserved.Öğe A new antimalarial quassinoid from Simaba orinocensis(American Chemical Society, 2004) Muhammad I.; Bedir E.; Khan S.I.; Tekwani B.L.; Khan I.A.; Takamatsu S.; Pelletier J.; Walker L.A.A new antimalarial quassinoid, namely, orinocinolide (1), was isolated from the root bark of Simaba orinocensis, together with the previously reported simalikalactone D (2). The structure of 1 was determined primarily from 1D and 2D NMR analysis, as well as by chemical derivatization. Compound 1 was found to be as equally potent as 2 against Plasmodium falciparum clones D6 and W2 (IC50 3.27 and 8.53 ng/ mL vs 3.0 and 3.67 ng/mL, respectively), but was 4- and 28-fold less toxic than 2 against VERO cells (IC50 10 vs 2.3 µg/mL) and HL-60 (IC50 0.7 vs 0.025 µg/mL), respectively. In addition, 2 was >46- and >31-fold more potent than pentamidine and amphotericin B (IC50 0.035 vs 1.6 and 1.1 µg/mL) against Leishmania donovani, while 1 was inactive. Orinocinolide (1) inhibited growth of human cancer cells SK-MEL, KB, BT-549, and SK-OV-3, but was less potent than 2 (IC50 0.8-1.9 vs 0.3-1.0 µg/mL) against these cells.Öğe A New ß-lapachone derivative from Distictella elongata (vahl) urb.(Sociedade Brasileira de Quimica, 2009) Bedir E.; Pereira A.M.S.; Khan S.I.; Chittiboyina A.; Moraes R.M.; Khan I.A.The present study describes the structure elucidation of the new ß-lapachone type naphthoquinone isolated from the roots of Distictella elongata. Its structure, according to the molecular formula C16H16O6, was identified as 4,7-dihydroxy-10-methoxy-2,2-dimethyl-3,4-dihydro-2H-benzo[h]chromene-5,6-dione. The structure was assigned by spectrometric methods [HRESIMS, 1D NMR (1H and 13C), and 2D NMR (g-DQF-COSY, g-HMQC and g-HMBC]. Root chloroform extract of D. elongata showed significant inhibition of the growth of SK-MEL (melanoma) and SK-OV-3 (ovary adenocarcinoma) cells with IC50 values of 40 µg mL-1 and 56 µg mL-1, respectively. However, the naphthoquinone was not responsible for the cytotoxic activity exhibited by the extract. ©2009 Sociedade Brasileira de Química.Öğe Patterns of essential oil relationships in Pimpinella (Umbelliferae) based on phylogenetic relationships using nuclear and chloroplast sequences(2005) Tabanca N.; Douglas A.W.; Bedir E.; Dayan F.E.; Kirimer N.; Baser K.H.C.; Aytac Z.; Khan I.A.; Scheffler B.E.Hydro-distilled essential oils from fruits, aerial parts (without fruits) and roots of Pimpinella species native to Turkey and their phylogenetic relationships to one another were examined. Phytochemical investigation of the essential oils of 19 species resulted in isolation of 16 phenylpropanoids, four sesquiterpenes and two azulene-type norsesquiterpenes. The structures of the isolated compounds were determined primarily from 1D- and 2D-NMR experiments as well as liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Phylogenetic relationships among 26 species were evaluated using ITS 1, ITS 4 nuclear rDNA and psbA-trnH cpDNA sequences. In this study, significance and occurrence of phenylpropanoids, azulenes and geijerenes are discussed from a phylogenetic, chemical and biosynthetic perspective. The distribution of different classes of compounds and their putative associations with one another as per current knowledge of their biosynthetic pathways indicates that this information, in conjunction with the phylogeny, could provide valuable information regarding the presence and perhaps evolution of the different classes of compounds. Analysis of the phenylpropanoid components indicates that (E)-anethole is an obligatory intermediate of this pathway. The various Pimpinella species differ primarily in their ability to acylate anethole, suggesting that while the pathway leading to anethole is common to this genus, species differ in their enzymatic machinery leading to acylate. The relationship between azulenes and geijerenes is not as intuitive, but all Pimpinella species analysed in this study have the biochemical machinery required to synthesize these chemical classes. © NIAB 2005.Öğe Phlinoside F, a new phenylethanoid glycoside from Phlomis angustissima(2005) Yalçin F.N.; Ersöz T.; Bedir E.; Şahpaz S.; Bailleul F.; Khan I.A.; Dönmez A.A.; Çaliş I.From the overground parts of Phlomis angustissima, a new phenylethanoid triglycoside, ß-(3-hydroxy,4-methoxyphenyl)ethyl-O-[ß- xylopyranosyl(1›2)-?-rhamnopyranosyl-(1›3)] -O-4-O-feruloyl- ß-glucopyranoside, named phlinoside F, was isolated along with the known compounds alyssonoside, samioside, lamiide, auroside, naringenin, and syringaresinol-4-O-ß-D-glucopyranoside. The structure of the new glycoside was elucidated by spectroscopic methods. © TÜBİTAK.Öğe Search for antifungal compounds from some Verbascum species growing in Turkey(2004) Tatli I.I.; Akdemir Z.Ş.; Bedir E.; Khan I.A.Turkish medicinal plants provide a rich source of biologically-active natural products. With the use of simple bioassays, it is possible to evaluate the bioactivity of the natural compounds. Antifungal screening of 16 compounds in a matrix format from two Verbascum species growing in Turkey was conducted directly on thin-layer chromatographic (TLC) plates sprayed with a spore suspension. Compounds possessing strong antifungal activity produced a clear zone of inhibition bounded by a sharp margin regardless of the size of the inhibitory zone. Ilwensisaponin A and C from Verbascum pterocalycinum var. mutense Hub.-Mor. were found to be active. Bioautographic assay indicated that the saponins appeared to be the most effective against Colletotrichum acutatum, C. fragariae and C. gloeosporioides.Öğe Secondary metabolites from Centaurea ensiformis P.H. Davis(2010) Baykan-Erel S.; Bedir E.; Khan I.A.; Karaalp C.Centaurea ensiformis P.H. Davis was evaluated for its secondary metabolites. 20 different compounds have been isolated and identified; four phenolic compounds, one aminoacid, two acetophenone glycosides, three phenylpropanoide glycosides, one coumarin glucoside, four flavon glycosides, two neolignan glycosides, two megastigmane glycosides and schikimic acid methyl ester. © 2010 Elsevier Ltd.Öğe Toxicity of cephalaria species and their individual constituents against aedes aegypti(Natural Product Incorporation, 2015) Sarikahya N.B.; Kayce P.; Tabanca N.; Estep A.S.; Becnel J.J.; Khan I.A.; Kirmizigul S.Crude acetone and ethanol extracts of the aerial parts of 21 Cephalaria species collected from Turkey were investigated for larvicidal and adult topical activity against Aedes aegypti. The ethanol extracts from C. Elazigensis var. purpurea, C. Anatolica, and C. Elmaliensis possessed the highest mortality against first instar Ae. Aegypti larvae. Luteolin-7-O-ß-D-glycoside (1), isolated from C. Elmaliensis ethanol extract, demonstrated 33% and 53% mortality at 0.1 µg/mL concentration against first instar ORL (susceptible) and PR (pyrethroid resistant) strains, respectively. C. scoparia acetone extract showed 100% mortality against adult Ae. Aegypti. From this extract compounds 2-8 were isolated. Compound 2 (isoorientin) possessed the highest toxicity with 31.7% and 65% mortality at a 10 µg/mL concentration against adult ORL and PR strains, respectively. This is the first screening report of potential insecticides from Cephalaria species against the yellow fever mosquito, Ae. Aegypti, and the active compounds (1 and 2) could lead to the development of a new class of insecticide.Öğe Triterpene saponins from Nigella sativa L(2005) Taşkin M.K.; Alankuş Çalişkan Ö.; Anil H.; Abou-Gazar H.; Khan I.A.; Bedir E.Three known triterpene glycosides were isolated from the MeOH extract of dried and powdered seeds of Nigella sativa. The structures of the compounds were established as 3-O-[ß-D-xylopyranosyl-(1›3)-?-L- rhamnopyranosyl-(1›2)-?-L-arabinopyranosyl]-28-O-[?-L- rhamnopyranosyl-(1›4)-ß-D-glucopyranosyl(1›6)-ß-D- glucopyranosyl]-hederagenin (1), 3-O-[?-L-rhamnopyranosyl-(1›2)- ?-L-arabinopyranosyl]28-O-[?-L-rhamnopyranosyl-(1›4) -ß-D-glucopyranosyl-(1›6)-ß-D-glucopyranosyl]-hederagenin (2), and 3-O-[ß-D-xylopyranosyl-(1›3)-?-L-rhamnopyranosyl-(1›2)- ?-L-arabinopyranosyl] -hederagenin (3) by means of chemical and spectral methods. Compound 2 was isolated for the first time from the genus Nigella. © TÜBİTAK.Öğe Two new iridoid glucosides from Verbascum salviifolium Boiss.(2005) Akdemir Z.S.; Tatli I.; Bedir E.; Khan I.A.From the aerial parts of the plant Verbascum salviifolium, two new iridoid glucosides, 6-O-ß-D-glucopyranosylcatalpol (1) and 6-O-(6¨-O-trans-p- hydroxycinnamoyl)-ß-D-glucopyranosylaucubin (2) along with five known iridoid glycosides, 6-O-ß-D-glucopyranosylaucubin (3), 6-O-?-L- rhamnopyranosylcatalpol (4), verbaspinoside [= 6-O-(2¨-O-trans-cinnamoyl)- ?-L-rnamnopyranosylcatalpol] (5), pulverulentoside I [= 6-O-(2¨-O-trans-p-methoxycinnamoyl-3¨-O-acetyl)-?-L- rhamnopyranosylcatalpol] (6), and buddlejoside A8 [= 6-O-(4¨-O-trans-3,4-dimethoxycinnamoyl)-?-L-rhamnopyranosylcatalpol] (7) were isolated. The structures of the new compounds were established on the basis of spectroscopic evidence.
