排序方式: 共有72条查询结果,搜索用时 218 毫秒
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Iranshahi M Shahverdi AR Mirjani R Amin G Shafiee A 《Zeitschrift für Naturforschung. C, Journal of biosciences》2004,59(7-8):506-508
The chloroform extract of Ferula persica var. persica roots was found to inhibit red pigment production of Serratia marcescens. A bioguided fractionation study by preparative thin layer chromatography (PTLC) detected a fraction (Rf = 0.71, petroleum ether/EtOAc, 2:1 v/v), which was effective on depigmentation of Serratia marcescens. Using conventional spectroscopy methods, the active fraction was identified as umbelliprenin. Neither the chloroform extract nor the isolated umbelliprenin fraction showed any antibacterial activity against the test strain at a certain concentration. In contrast, they exhibited depigmentation zones on culture plates. 相似文献
33.
Mahdiyeh Hassanpour-Khaneghah Mortaza Iranifam Abdolhossein Naseri Haider A. J. Al Lawati 《Luminescence》2022,37(7):1184-1191
In this article, nickel(II) oxide (NiO) hollow microspheres (HMSs) were fabricated and used to catalyze chemiluminescence (CL) reaction. The studied CL reaction is the luminol-oxygen reaction that was used as a sensitive analytical tool for measuring tuberculostatic drug isoniazid (IND) in pharmaceutical formulations and water samples. The CL method was established based on the suppression impact of IND on the CL reaction. The NiO HMSs were produced by a simple hydrothermal method and characterized by several spectroscopic techniques. The result of essential parameters on the analytical performance of the CL method, including concentrations of sodium hydroxide (NaOH), luminol, and NiO HMSs were investigated. At the optimum conditions, the calibration curve for IND was linear in the range of 8.00 × 10−7 to 1.00 × 10−4 mol L−1 (R2 = 0.99). A detection limit (3S) of 2.00 × 10−7 mol L−1 was obtained for this method. The acceptable relative standard deviation (RSD) was obtained for the proposed CL method (2.63%, n = 10) for a 5.00 × 10−6 mol L−1 IND solution. The mechanism of the CL reaction was also discussed. 相似文献
34.
Eimani H Mamzoji SS Soleimani MM Abnosi MH Valojerdi MR Yazdi PE Shahverdi A Guorabi H 《BioFactors (Oxford, England)》2007,31(2):117-126
The aim of this study was to investigate the growth and survival rate of preantral follicles isolated from vitrified ovarian tissue by Cryotop and conventional methods. The ovaries of 14-day-old mice were separated and divided into four groups as following: Cryotop group, vitrified by Cryotop; CV (Conventional; CV) group, vitrified by conventional straw; toxicity test group and control group. After warming the vitrified ovaries, isolated preantral follicles from four groups were cultured for 4 days to compare survival rate and follicular growth between above-mentioned groups. Survival rate (97.3%) in toxicity test group alike the control group (98.7%) were significantly higher (P<0.05) than the Cryotop (92.7%) and CV (47.7%) groups. Increase in follicle diameters after 4 days in Cryotop and CV groups was significantly lower (P<0.05) than the control and toxicity test groups, but growth and survival rate of follicles in Cryotop group was significantly higher (P<0.05) than the CV group. These results demonstrated that ovarian tissue vitrification by Cryotop highly preserves the viability rate of preantral follicles. 相似文献
35.
The investigation of the polar fractions of the aerial parts of O. leptolepis afforded two new elemanolides, their structures being elucidated by spectroscopic methods and by partial synthesis starting with onopordopicrin. 相似文献
36.
A.R. Shahverdi F. Saadat M.R. Khorramizadeh M. Iranshahi M.R. Khoshayand 《Phytomedicine》2006,13(9-10):712-717
Matrix metalloproteinases (MMPs) play a role in several physiologic and pathologic events. There is some evidence indicating the involvement of MMPs in tumor invasion and inflammatory diseases. Here we studied the chloroform extract of Ferula persica var. persica. The influence of these extracts vs. a reference drug, diclofenac sodium, on MMP production by the fibrosarcoma cell line was investigated using an in vitro cytotoxicity assay, sodium dodecyl sulfate-polyacrylamide, and gelatin zymography. The total extract of the roots was found to exhibit a selective inhibitory effect on tumor cell invasion. The bioactivity-guided fractionation of this extract led to the isolation of two compounds. These compounds showed highest MMP inhibitory effect at minimal toxic dose levels. Using conventional spectroscopy methods, the active fractions were identified as t-butyl 3-[(1-methylthiopropyl)dithio]-2-propenyl malonate (persicasulphide B) and umbelliprenin, previously isolated from F. persica var. latisecta. Since inhibition of MMP activity has been employed in modality therapy in diseases such as cancer, this compound might be promising in the preparation of anti-MMP therapeutic derivatives. 相似文献
37.
Mohammad-Hossein Sorouraddin Kaveh Amini Abdolhossein Naseri Javad Vallipour Jalal Hanaee Mohammad-Reza Rashidi 《Journal of biosciences》2010,35(3):395-403
Lineweaver-Burk plot analysis is the most widely used method to determine enzyme kinetic parameters. In the spectrophotometric
determination of enzyme activity using the Lineweaver-Burk plot, it is necessary to find a wavelength at which only the substrate
or the product has absorbance without any spectroscopic interference of the other reaction components. Moreover, in this method,
different initial concentrations of the substrate should be used to obtain the initial velocities required for Lineweaver-Burk
plot analysis. In the present work, a multi-wavelength model-based method has been developed and validated to determine Michaelis-Menten
constants for some enzyme reactions. In this method, a selective wavelength region and several experiments with different
initial concentrations of the substrate are not required. The absorbance data of the kinetic assays are fitted by non-linear
regression coupled to the numeric integration of the related differential equation. To indicate the applicability of the proposed
method, the Michaelis-Menten constants for the oxidation of phenanthridine, 6-deoxypenciclovir and xanthine by molybdenum
hydroxylases were determined using only a single initial concentration of the substrate, regardless of any spectral overlap. 相似文献
38.
Fakhimi A Iranshahi M Emami SA Amin-Ar-Ramimeh E Zarrini G Shahverdi AR 《Zeitschrift für Naturforschung. C, Journal of biosciences》2006,61(9-10):769-772
In this study the enhancement effect of Sophora pachycarpa roots' acetone extract on the antibacterial activity of gentamycin was evaluated against Staphylococcus aureus. Disc diffusion and broth dilution methods were used to determine the antibacterial activity of gentamycin in the absence and presence of plant extract and its various fractions separated by TLC. A clinical isolate of S. aureus was used as test strain. The active component of the plant extract involved in enhancement of gentamycin's activity had Rf = 0.72 on a TLC plate. The spectral data (1H NMR, 13C NMR) of this compound revealed that this compound was 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone (sophoraflavanone G), previously isolated from Sophora exigua. In the presence of 0.03 microg/ mL of sophoraflavanone G the MIC value of gentamycin for S. aureus decreased from 32 to 8 microg/mL (a four-fold decrease). These results signify that the ultra-low concentration of sophoraflavanone G potentiates the antimicrobial action of gentamycin suggesting a possible utilization of this compound in combination therapy against Staphylococcus aureus. 相似文献
39.
Iranshahi M Hosseini ST Shahverdi AR Molazade K Khan SS Ahmad VU 《Phytochemistry》2008,69(15):2753-2757
Seven sesquiterpene lactone derivatives, diversolides A-G (1-7), together with two known compounds, diversin (8) and stigmasterol, were isolated from the roots of Ferula diversivittata. The structures of these compounds were elucidated by extensive spectroscopic methods including 1D-(1H and 13C) and 2D-NMR experiments (DQF-COSY, HSQC, HMBC, and NOESY) as well as high-resolution EIMS. Compounds 1, 4 and 6-8 were tested for their in vitro antifungal and antibacterial activities. Some of the tested compounds showed moderate antifungal and antibacterial activities with minimum inhibitory concentration (MIC) values from 40 to 80 μg/ml. 相似文献
40.
Abdolhossein Rustaiyan Minoo Dabiri Rajinder K. Gupta Ferdinand Bohlmann 《Phytochemistry》1981,20(6):1429-1430
A sesquiterpene glycoside has been isolated from the aerial parts of Carthamus turkistanikus and identified as α-bisabolol-β-desoxy-p-altropyra 相似文献