排序方式: 共有9条查询结果,搜索用时 15 毫秒
1
1.
Reza Dowlatabadi Farshad Farshidfar Zohreh Zare Morteza Pirali Maryam Rabiei Mohammad Reza Khoshayand Hans J. Vogel 《Metabolomics : Official journal of the Metabolomic Society》2017,13(2):19
Introduction
The high market value of saffron (Crocus sativus L.) has made it an attractive candidate for adulteration. Safflower (Carthamus tinctorius L.) and tartrazine are among the most common herbal and synthetic foreign materials that may be added to pure saffron for the purpose of adulteration. In spite of encouraging advances achieved in the identification of adulteration in saffron samples, the lack of a simple method with sufficient power for discrimination of pure high grade saffron from meticulously adulterated saffron samples persuaded us to perform this study.Objectives
In this work, we show that 1H NMR spectroscopy together with chemometric multivariate data analysis methods can be used for the detection of adulteration in saffron.Methods
Authentic Iranian saffron samples (n?=?20) and adulterated samples that were prepared by adding either different quantities of natural plant materials such as safflower, or synthetic dyes such as tartrazine or naphthol yellow to pure saffron (n?=?22) composed the training set. This training set was used to build multivariate Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) models. The predictive power of the PLS-DA model was validated by testing the model against an external dataset (n?=?13).Results
PCA and PLS-DA models could both discriminate between the authentic and adulterated samples, and the external validation showed 100% sensitivity and specificity for predicting the authenticity of suspicious samples. Peaks specific to authentic and adulterated samples were also characterized. Proximity of samples with unknown adulteration status to the samples adulterated with known compounds in the PCA provided insight regarding the identity of the adulterant in the suspicious samples. Furthermore, the authentic samples could be distinguished based on their cultivation site.Conclusion
The present study demonstrates that the application of 1H NMR spectroscopy coupled with multivariate data analysis is a suitable approach for detection of adulteration in saffron specimens. Outstanding sensitivity and specificity of the PLS-DA model in discriminating the authentic from adulterated samples in external validation confirmed the high predictive power of the model. The advantage of the present method is its power for detecting a wide spectrum of adulterants, ranging from synthetic dyes to herbal materials, in a single assay.2.
Reza Ahmadkhaniha Abbas Shafiee Noushin Rastkari Mohammad Reza Khoshayand Farzad Kobarfard 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(11-12):845-852
Providing “real blank sample” is a problem in determination of endogenous steroids in complex matrices. A new quantification strategy is proposed in the present study, which is based on using isotope-labeled steroids instead of natural steroids for constructing calibration line. This approach is called surrogate analyte and it is shown that its accuracy is better than some of the previously described methods at low concentrations and comparable to standard addition method at medium and high concentration levels. The method was fully validated to satisfy the ICH criteria and it was applied for determination of endogenous steroids in several urine samples. 相似文献
3.
Tarane Gazori Mohammad Reza Khoshayand Ebrahim Azizi Parisa Yazdizade Alireza Nomani Ismaeil Haririan 《Carbohydrate polymers》2009,77(3):599-606
Nanoparticles comprising Alginate/Chitosan polymers were prepared by pregel preparation method through drop wise addition of various concentrations of CaCl2 to a defined concentration of Sodium Alginate. Then, Chitosan/Antisense solution with a certain N/P ratio was added to the pregel to make the nanoparticles. The effect of such parameters as polymer ratio, CaCl2/Alginate ratio and N/P ratio on the particle size distribution and loading efficacy was studied. The optimum conditions were 1:1 (w/w) Alginate to Chitosan ratio, 0.2% CaCl2/Alginate ratio and N/P ratio of 5 at pH 5.3. The resulting nanoparticles had a loading efficacy of 95.6% and average size of 194 nm as confirmed by PCS method and SEM images showed spherical and smooth particles. The zeta potential of optimized nanoparticles prepared by this method was about +30 mV which could result in good stability of nanoparticles during manipulation and storage. 相似文献
4.
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
5.
The aim of this study was the preparation, optimization, and in vitro characterization of insulin nanoparticles composed of methylated N-(4-N,N-dimethylaminobenzyl), methylated N-(4-pyridinyl), and methylated N-(benzyl) chitosan. Three types of derivatives were synthesized by the Schiff base reaction followed by quaternization. Nanoparticles
were prepared by the polyelectrolyte complexation method. Experimental design D-optimal response surface methodology was used for the optimization of the nanoparticles. Independent variables were pH of
polymer solution, concentration ratio of polymer/insulin, and also polymer type. Dependent variables include size, zeta potential,
polydispersity index (PdI), and entrapment efficiency (EE%). Optimized nanoparticles were studied morphologically by transmission
electron microscopy (TEM), and in vitro release of insulin from nanoparticles were determined under phosphate buffer (pH = 6.8) condition. Although a quadratic model
has been chosen to fit the responses for size, PdI, and EE%, the zeta potential of the particles has been best fitted to 2-FI
model. The optimized nanoparticles were characterized. The size of the particles were found to be 346, 318, and 289 nm; zeta
potentials were 28.5, 27.7, and 22.2 mV; PdI of particles were 0.305, 0.333, and 0.437; and calculated EE% were 70.3%, 84.5%,
and 69.2%, for methylated (aminobenzyl), methylated (pyridinyl), and methylated (benzyl) chitosan nanoparticles, respectively.
TEM images show separated and non-aggregated nanoparticles with sub-spherical shapes and smooth surfaces. An in vitro release study of the prepared nanoparticles showed that the cumulative percentage of insulin released from the nanoparticles
were 47.1%, 38%, and 68.7% for (aminobenzyl), (pyridinyl), and (benzyl) chitosan, respectively, within 300 min. 相似文献
6.
Rezaie Rezvan Rezaei Shahla Jafari Nasrin Forootanfar Hamid Khoshayand Mohammad Reza Faramarzi Mohammad Ali 《Extremophiles : life under extreme conditions》2017,21(6):993-1004
Extremophiles - Lignocellulose bioconversion is a harsh process requiring the use of surfactants and organic solvents. Consequently, the incorporation of laccases in this bioconversion requires the... 相似文献
7.
Khalaj A Doroudi AR Ostad SN Khoshayand MR Babai M Adibpour N 《Bioorganic & medicinal chemistry letters》2006,16(23):6034-6038
Two novel dual functional agents, 3[3-(2,4-dinitro-phenylamino)-propyl]-5-fluoro-1H-pyrimidine-2,4-dione 7 and N-[3-(2,4-dinitro-phenylamino)-propoxy]urea 8, resulting from linkage of 2,4-dinitrophenylamine through three carbon atoms with 5-fluorouracil 5 and hydroxyurea 6, respectively, were prepared and their in vitro aerobic cytotoxicities in HT-29 cell line with and without radiation were determined. Compounds 7 and 8 unlike their components were not cytotoxic but showed radiosensitizing activity. 相似文献
8.
9.
Feriyar Khoshayand Sanaz Goodarzi Ahmad Reza Shahverdi Mohammad Reza Khoshayand 《Probiotics and antimicrobial proteins》2011,3(3-4):159-167
Soymilk was fermented with Lactobacillus casei, and statistical experimental design was used to investigate factors affecting viable cells of L. casei, including temperature, glucose, niacin, riboflavin, pyridoxine, folic acid and pantothenic acid. Initial screening by Plackett-Burman design revealed that among these factors, temperature, glucose and niacin have significant effects on the growth of L. casei. Further optimization with Box-Behnken design and response surface analysis showed that a second-order polynomial model fits the experimental data appropriately. The optimum conditions for temperature, glucose and niacin were found to be 15.77 °C, 5.23 and 0.63 g/L, respectively. The concentration of viable L. casei cells under these conditions was 8.23 log10 (CFU/mL). The perfect agreement between the observed values and the values predicted by the equation confirms the statistical significance of the model and the model’s adequate precision in predicting optimum conditions. 相似文献
1