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141.
Hybrid identification of 16 sunflower hybrids was confirmed using simple-sequence repeat methodology. Of 20 specific simple-sequence repeat primers, 18 authenticated the purity of these hybrids; the remaining two specific primer pairs gave ambiguous DNA fragments. The results indicate that simple-sequence repeat analysis for the identification of hybrids derived from the crossing of different inbred sunflower lines can improve the accuracy of selection, save time and reduce cost. 相似文献
142.
Shahid Umar Iram Diva Naser A. Anjum Muhammad Iqbal Iqbal Ahmad Eduarda Pereira 《Central European Journal of Biology》2011,6(6):1054-1063
Salinity is an important abiotic factor that adversely affects major agricultural soils of the world and hence limits crop
productivity. An optimum mineral-nutrient status of plants plays critical role in determining plant tolerance to various stresses.
A pot experiment was conducted on mustard (Brassica campestris L.) to study the protective role of added potassium (K, 40 mg kg−1 soil) against salinity-stress (0, 40 and 80 mM NaCl)-induced changes in plant growth, photosynthetic traits, ion accumulation,
oxidative stress, enzymatic antioxidants and non-enzymatic antioxidants at 30 days after sowing. Increasing NaCl levels decreased
the growth, photosynthetic traits and the leaf ascorbate and glutathione content but increased the leaf ion accumulation and
oxidative stress, and the activity of antioxidant enzymes. In contrast, K-nutrition improved plant growth, photosynthetic
traits, activity of antioxidant enzymes and the ascorbate and glutathione content, and reduced ion accumulation and oxidative
stress traits in the leaves, more appreciably at 40 mM than at 80 mM NaCl. The study illustrates the physiological and biochemical
basis of K-nutrition-induced NaCl tolerance in mustard as a means to achieving increased crop productivity in a sustainable
way. 相似文献
143.
144.
The microbial transformation of the 17alpha-ethynyl-17beta-hydroxyandrost-4-en-3-one (1) (ethisterone) and 17alpha-ethyl-17beta-hydroxyandrost-4-en-3-one (2) by the fungi Cephalosporium aphidicola and Cunninghamella elegans were investigated. Incubation of compound 1 with C. aphidicola afforded oxidized derivative, 17alpha-ethynyl-17beta-hydroxyandrosta-1,4-dien-3-one (3), while with C. elegans afforded a new hydroxy derivative, 17alpha-ethynyl-11alpha,17beta-dihydroxyandrost-4-en-3-one (4). On the other hand, the incubation of compound 2 with the fungus C. aphidicola afforded 17alpha-ethyl-17beta-hydroxyandrosta-1,4-dien-3-one (5). Two new hydroxylated derivatives, 17alpha-ethyl-11alpha,17beta-dihydroxyandrost-4-en-3-one (6) and 17alpha-ethyl-6alpha,17beta-dihydroxy-5alpha-androstan-3-one (7) were obtained from the incubation of compound 2 with C. elegans. Compounds 1-6 exhibited tyrosinase inhibitory activity, with compound 6 being the most potent member (IC(50)=1.72 microM). 相似文献
145.
Mahroof-Tahir M Brezina D Fatima N Choudhary MI Atta-ur-Tahman 《Journal of inorganic biochemistry》2005,99(2):589-599
The increasing interest in vanadium coordination chemistry is based on its well-established chemical and biological functions. A beta-diketonato complex of oxovanadium(IV) is known to be having numerous catalytic applications and also exhibits promising insulin mimetic properties. In continuation of our structure activity relationship studies of metal complexes, we report herein the synthesis and characterization of the vanadium complexes of beta-diketonato ligand system with systematic variations of electronic and steric factors. Two complexes, VO(tmh)(2) (tmh = 2,2,6,6,-tetramethyl-3,5-heptanedione), and VO(hd)(2) (hd = 3,5-heptanedione) were synthesized and characterized by using different spectroscopic techniques. Elemental and mass spectral analysis supports the presence of two beta-diketonato ligands per VO(2+) unit. UV-Vis spectra in different solvents indicate coordination of coordinating solvent molecules at sixth position resulting in red shift of the band I transition. NMR and IR spectra reveal binding of coordinating solvent molecule at vacant sixth position trans to oxo group without releasing beta-diketonato ligands. Enzyme inhibition studies of these and other related oxovanadium(IV) complexes with beta-diketonato ligand system are conducted with snake venom phosphodiesterase I (SPVDE). All of these complexes showed significant inhibitory potential and were found to be non-competitive inhibitors against this enzyme. 相似文献
146.
Ahmad AS Zia S Sayeed I Ansari MA Ahmad M Salim S Yousuf S Islam F 《Biological trace element research》2005,103(1):59-68
The effect of 0.05, 0.1, and 0.2 mg sodium selenite/kg body weight ip on the activities of neurobehavioral, acetyl cholinesterase,
monoamine oxidase, and the content of dopamine and its metabolites in circadian rhythm centers of male Wistar rats was studied
after 7 d of treatment. The results show an appreciable increase in locomotion, stereo-events, distance traveled, and average
speed at the dose of 0.1 and 0.2 mg sodium selenite/kg. The data have shown hyperactivity of animals with various doses of
sodium selenite, and it was significant and dose-dependent after 3 d of treatment. The activity of acetylcholinesterase (AChE)
was inhibited dose dependently, and it was significant in preoptic area with 0.1 or 0.2 mg sodium selenite/kg. Conversely,
in the posterior hypothalamus its activity was significantly elevated with the dose of 0.2 mg sodium selenite/kg, but its
alteration in brain stem was not significant. Monoamine oxidase (MAO) activity was increased in preoptic area with the dose
of 0.1 mg sodium selenite/kg, but its alteration in posterior hypothalamus and brain stem was not significant. The content
of dopamine (DA), 3,4-dihydroxyphenyl acetic acid (DOPAC), and homovanilic acid (HVA) was elevated dose dependently and it
was significant with the doss of 0.1 and 0.2 mg sodium selenite/kg, but the content of DOPAC and HVA in posterior hypothalamus
was not significant with the dose of 0.1 mg sodium selenite/kg. 相似文献
147.
Two new prenylated anthronoids, harunmadagascarins A and B, were isolated from the stem bark of Harungana madagascariensis along with six known compounds including two anthronoids: harunganol B and harungin anthrone, one benzophenone: methyl 3-formyl-2,4-dihydroxy-6-methyl benzoate and three pentacyclic triterpenes: friedelin, lupeol and betulinic acid. Harunmadagascarins A and B were characterized as 8,9-dihydroxy-4,4-bis-(3,3-dimethylallyl)-6-methyl-2,3-(2,2-dimethylpyrano)anthrone and 8,9-dihydroxy-4,4,5-tris-(3,3-dimethylallyl)-6-methyl-2,3-(2,2-dimethylpyrano)anthrone, respectively. The structures of these secondary metabolites were determined by spectroscopic means and comparison with the published data. Methyl 3-formyl-2,4-dihydroxy-6-methyl benzoate was isolated for the first time from a plant. Harunmadagascarins A and B, harunganol B and harungin anthrone exhibited significant antioxidant activity. 相似文献
148.
Choudhary MI Musharraf SG Nawaz SA Anjum S Parvez M Fun HK Atta-ur-Rahman 《Bioorganic & medicinal chemistry》2005,13(6):1939-1944
The microbial transformation of (-)-isolongifolol (1) by using the standard two-stage fermentation technique with Fusarium lini afforded polar oxygenated metabolites: 10-oxoisolongifolol (2), 10alpha-hydroxyisolongifolol (3), and 9alpha-hydroxyisolongifolol (4). Metabolites 3 and 4 were also formed with the incubation of 1 with Aspergillus niger. All three metabolites were found to be new. Compounds 3 and 4 inhibited butyrylcholinesterase enzyme in a concentration-dependent manner with IC50 values 13.6 and 299.5 microM, respectively. Compound 3 showed un-competitive mode of inhibition against butyrylcholinesterase with Ki value 15.0 microM. The structures of metabolites 2-4 were deduced on the basis of spectroscopic techniques and single-crystal X-ray diffraction techniques. 相似文献
149.
Amor EC Villaseñor IM Ghayur MN Gilani AH Choudhary MI 《Zeitschrift für Naturforschung. C, Journal of biosciences》2005,60(1-2):67-71
The hexane extract of Syzygium samarangense (Ss.Hex) dose-dependently (10-1000 microg/ ml) relaxed the spontaneously contracting isolated rabbit jejunum. Four rare C-methylated flavonoids with a chalcone and a flavanone skeleton were isolated from Ss.Hex and were subsequently tested for spasmolytic activity. All flavonoids, identified as 2'-hydroxy-4',6'-dimethoxy-3'-methylchalcone (1), 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (2), 2',4'-dihydroxy-6'-methoxy-3'-methylchalcone (3), and 7-hydroxy-5-methoxy-6,8-dimethyl-flavanone (4), showed dose-dependent spasmolytic activity in the rabbit jejunum with IC50 values of 148.3 +/- 69.4, 77.2 +/- 43.5, 142.4 +/- 58.6 and 178.5 +/- 37.5 microg/ml (mean +/- SEM), respectively. The dihydrochalcone derivative of compound 1, 2'-hydroxy-4',6'-dimethoxy-3'-methyldihydrochalcone (5), when tested for spasmolytic activity, did not significantly relax the smooth muscle relative to the other compounds. Verapamil, a standard spasmolytic, has an IC50 value of 0.16 +/- 0.04 microg/ml. This is the first report of the relaxant activity of chalcones, specifically of compounds 1-3. 相似文献
150.
Khan T Ahmad M Nisar M Ahmad M Lodhi MA Choudhary MI 《Journal of enzyme inhibition and medicinal chemistry》2005,20(3):245-249
The ethanolic extract derived from aerial parts of an indigenous medicinal plant Paeonia emodi was screened for enzyme inhibition activities against Urease (jack bean and Bacillus pasteurii) and alpha-Chymotrypsin. The extract was also investigated for its radical scavenging activity using DPPH assay. The crude extract was found to possess significant enzyme inhibition activities against jack bean (74%) and Bacillus pasteurii (80%) urease and a moderate activity (54%) against alpha-Chymotrypsin. The extract also displayed excellent (83%) radical scavenging activity. On the basis of these results, the crude extract was subsequently fractionated into n-hexane, chloroform, ethyl acetate, n-butanol and water fractions and tested independently for the aforesaid activities. Significant inhibitory activity against urease enzyme was observed for the ethyl acetate, n-butanol and water fractions while the n-hexane and chloroform fractions were devoid of any such activity. In the alpha-Chymotrypsin enzyme inhibition studies the activity was concentrated into the ethyl acetate fraction. All the fractions displayed potent radical scavenging activity. The crude extract and fractions thereof were also subjected to total phenolic content determination. A correlation between radical scavenging capacities of extracts and total phenolic content was observed in the majority of cases. 相似文献