Optimization of Ultrasound-assisted Extraction of Phenolic Compounds from Yarrow (Achillea beibrestinii) by Response Surface Methodology

Davoud Salar Bashi,Seyyed Ali Mortazavi,Karamatollah Rezaei,Ahmad Rajaei,Mohamad Mahdi Karimkhani 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.4

An efficient ultrasound-assisted extraction (UAE)technique was applied to extract total phenolic content (TPC) from yarrow (Achillea beibrestinii). A response surface methodology was employed to evaluate the effects of 4 independent variables (temperature, pH, solvent to sample ratio, and time) on the TPC. The optimum extraction conditions were as follows: liquid to solid ratio 20, pH 6.3, extraction temperature 35oC, and extraction time 35 min. Under the above-mentioned conditions, the experimental TPC was 11.7 mg gallic acid equivalent/g dry matter. EC50 of the UAE extract at optimal conditions was found at 30.6±0.6 mg/L level and total flavonoids (TF)were obtained at 12.6±0.2 mg/10 g sample. Also, the results of HPLC analysis showed that gallic acid and pcoumaric acid were the predominant phenolic compounds in the plant.

An Improved Convergent Approach for Synthesis of Erlotinib, a Tyrosine Kinase Inhibitor, via a Ring Closure Reaction of Phenyl Benzamidine Intermediate

Davoud Asgari,Ayuob Aghanejad,Javid Shahbazi Mojarrad 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.3

An improved convergent and economical method has been developed for the synthesis of erlotinib, a 4-anilinoquinazoline and an EGFR-tyrosine kinase inhibitor for treatment of non-small-cell lung cancer. The final two steps for the formation of this 4-anilinoquinazoline from suitable 2-aminobenzonitrile intermediate and 3-ethynylaniline were modified and were performed in a simple one-pot reaction. The ring-closing mechanism for the formation of erlotinib from the suitable formamidine intermediate and 3-ethynylaniline was investigated and determined to proceed via the formation of phenyl benzamidine intermediate rather than involving Dimroth rearrangement reported earlier. The new benzamidine intermediate was isolated for the first time and characterized.

Autolysin (lytA) recombinant protein: a potential target for developing vaccines against pneumococcal infections

Davoud Afshar,Farzaneh Rafiee,Mozhgan Kheirandish,Solmaz Ohadian Moghadam,Mohammad Azarsa 대한백신학회 2020 Clinical and Experimental Vaccine Research Vol.9 No.2

Purpose: N-acetylmuramoyl-l-alanine amidase known as lytA, is an immunogenic protein that plays an important role in the pathogenesis of Streptococcus pneumoniae. It is highly conserved among S. pneumoniae strains and is absent among other Streptococcus species. In the present study, the level of antibodies against the lytA recombinant protein was evaluated in healthy individuals’ sera. Materials and Methods: DNA was extracted from S. pneumoniae ATCC 49619 to amplify lytA gene by polymerase chain reaction assay. The lytA amplicon and pET28a vector were separately double digested using Nde-1 and Xho1 restriction enzymes and then ligated together with ligase enzyme. The recombinant plasmid was expressed in Escherichia coli BL21 strain and the lytA recombinant protein purified using nickel-nitrilotriacetic acid affinity chromatography. Western blot was carried to detect lytA recombinant protein. Sixty healthy individual’s sera (at three age groups: group 1, <2; group 2, 2–40; and group 3, 60–90 years old) were collected and the titers of anti-lytA antibodies were determined. Results: The lytA gene was highly expressed in E. coli BL21 host. The recombinant lytA protein was purified and confirmed by western blotting. Tukey test analysis showed that there were no significant differences among the age groups considering the anti-lytA titer of 10. However, at the anti-lytA titer of 60, significant differences were observed between group 1 vs. group 2 (p<0.001); group 1 vs. group 3 (p=0.003), and group 2 vs. group 3 (p=0.024). Conclusion: The lytA protein seems to be a highly immunogenic antigen and a potential target for developing vaccines against pneumococcal infections.

An experimental study on polymer cathode materials in lead-acid battery energy storage systems

Davoud Jahani,Amin Nazari,Mohammadreza Yazdan Panah,Nader Javani,Fatemeh Moharaminezhad 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.8

The replacement of lead grids with acrylonitrile butadiene styrene (ABS) polymer grids in the negativeelectrode of lead-acid batteries was studied experimentally, while the positive electrode remained unchanged. A polymergrid was activated by nickel plating using a chemical solution, and then coated with chrome and copper conductiveplating. The polymer grid was coated with a layer of lead. Using a lead-coated polymer grid, a 30-amp 12-voltbattery was produced and tested, and the results were compared with a 30-hour production line lead-acid battery. Theresults show that the polymer grid has a strong ability to generate an appropriate voltage in the charge and dischargecycle and create a stable capacity. The results also show the polymer grid weight has decreased significantly (about50%) compared to the conventional lead grid. In this work, the adhesion of a negative paste to the surface of the polymergrid covered with the lead-exposed expand grid was studied, and the results show that the polymer grid canadhere to the negative dough perfectly.

Determination Moisture Stress Pistachio Tree by Using Sap Flow Measurement

Davoud Zarehaghi,Mohammad Reza Neyshabouri,Manoucher Gorji 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Biodiversity status of Tulipa (Liliaceae) in Iran inferred from molecular characterization

Davoud Asgari,Alireza Babaei,Mohammad Reza Naghavi,Mahmoud Kiani 한국원예학회 2020 Horticulture, Environment, and Biotechnology Vol.61 No.3

Here, we used data generated from amplifi ed fragment length polymorphism (AFLP) analysis to address the biodiversitystatus and taxonomic relationships among 47 wild accessions representing 9 species of the genus Tulipa in Iran. A high levelof genetic diversity within the genus was observed; the most distant taxa were T. humilis and T. schrenkii , while the highestdegree of similarity was found between T. montana and T. bifl ora . Twelve AFLP primer sets amplifi ed 342 fragments, ofwhich 304 were polymorphic (88.1%). The average number of polymorphic bands per AFLP primer pair was 28.5. A hierarchicalcluster analysis was carried out on the genetic profi le of the taxa, and the results mostly reconfi rmed the recognizedtaxonomy of the genus. However, we found evidence for recognition of a new subgenus for T. biebersteiniana .

Circadian variation in midgut digestive enzyme activity in cotton bollworm Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

Davoud Mohammadi,Reza Farshbaf Pour Abad,Mohammad Reza Rashidi,S. AbolghasemMohammadi 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.2

In this study, total protease, α-amylase and lipase activity of cotton bollworm were studied under four different photoperiod regimes. Insects were reared from first larval stages on artificial diet under controlled conditions (26 ± 2 °C temperature, 60 ± 5 % RH) in incubators under four photoperiod regimes, including light (24: 0), dark (0: 24), 12:12 h (L:D) and 16:8 h (L:D). Sixth larval stage was used for enzyme assays and after dissection, alimentary canal of larva was separated frombody and transferred to 1.5 ml micro tubes containing 1 ml cold glycine– NaOH, pH 10 buffer. Contents of tubeswere homogenized and centrifuged, and the supernatantswere used as enzyme source. Samplingwas carried out for 24 h at 3 h intervals. The enzyme activity (α-amylase and lipase) wasmeasured using diagnostic kit and azocaseinolytic assay carried out for total protease assays. Results indicated that photoperiod regimes changed enzyme activity profile, and digestive enzyme activity was significantly changed during the diel period. Alpha-amylase activity increased from 9:00 h to 15:00 h in all the studied photoperiods. Alpha-amylase and lipase activity in light photoperiod wasmore than the dark one, but total protease activity increased in dark photoperiod especially from12:00 to 18:00 h, compared with the other photoperiods. A slight increase in digestive enzyme activity was observed at 3:00 h in light and dark photoperiods.

Semi-analytical solution for time-dependent deformations in swelling rocks around circular tunnels

Davoud Parsapour,Ahmad Fahimifar 한국지질과학협의회 2016 Geosciences Journal Vol.20 No.4

Underground structures in swelling rocks bear timedependent swelling effects. Upon excavation of underground spaces, the state of stresses and displacements change compared with the initial state. The stress and displacement variations depend on tunnel advance and the rheological behavior of surrounding rock mass. The swelling behaviour of rocks is known as a complicated phenomenon and very important task in tunnel design process. The paper aim is to predict the time-dependent displacement of the tunnel after the excavation has stopped or after installing the support system. The assumption is made that the medium around tunnel is both isotropic and homogenous. The section of tunnel is also assumed circular which in view of stress field, is excavated in Hydrostatic and non-hydrostatic conditions. A semi-analytical model on the basis of experimental results is adopted to evaluate the ground swelling strains as a function of time and stress. Given the current assumptions and conditions, a semi-analytical solution is derived to predict the time-dependent displacements and lining pressure for a circular shaped tunnel section in a swelling ground. Eventually, the model is loaded by an axisymmetric far-field pressure and the effect of the tunnel face on the lining pressure is also considered. On the whole, the comparison between modeling results and actual data, proved an accordance between them. As the results indicate, such parameters as, time dependent modulus of swelling and swelling strain coefficient as well as the initial aspect ratio, play a prominent role in controlling the swelling deformations. The set up time of lining is also considered as an impressing factor controlling the swelling pressure. In mediums of high swelling potential, the temporary support system installation has to be made to allow some ground deformations prior to the permanent support (lining) gets installed which causes the swelling deformation to get relieved.

Organic–inorganic Z-scheme g-C3N4-NiTi-layered double hydroxide films for photocatalytic applications in a fixed-bed reactor

Davoud Yazdani,Ali Akbar Zinatizadeh,Mohammad Joshaghani 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.63 No.-

A novel graphitic carbon nitride g-C3N4-NiTi-layered double hydroxide heterojunction film photo-catalyst (g-C3N4-NiTi-LDH) was prepared by facile hydrothermal synthesis. The g-C3N4 and g-C3N4-NiTi-LDH film samples were characterized by AFM, SEM, EDX, PL, XRD and DRS analysis. DRS analysis indicated a significant red shift of absorption edge due to the interfacial coupling effect between g-C3N4 and NiTi-LDH. PL analysis showed an efficient inhibition of electron-hole recombination in the blended g-C3N4-NiTi-LDH. A fixed-bed photoreactor containing conjugated g-C3N4-NiTi-LDH film-coated glass was fabricated and employed to photocatalytic degradation of methyl orange (MO). As a result, the g-C3N4-NiTi-LDH film showed greater photocatalytic activity compared with pure samples of g-C3N4 and NiTi-LDH film samples. Maximum MO degradation efficiency (100%) was achieved using g-C3N4-NiTi-LDH films within 240 min.

Spatial Memory and Antioxidant Protective Effects of Raisin (Currant) in Aged Rats

Davoud Ghorbanian,Mohammed Gol,Mohsen Pourghasem,Jamshid Faraji,Kaveh Pourghasem,Nabiollah Soltanpour 한국식품영양과학회 2018 Preventive Nutrition and Food Science Vol.23 No.3

Diets rich in fruits and vegetables can prevent age-related diseases. This research was conducted to evaluate the effects of raisin consumption on the spatial memory and morphometric parameters of brain tissue in aging rats. Old rats (20 months of age) were divided into 2 groups: control and raisin, with 6 rats in each group. The raisin group received 6 g of raisins daily in addition to their food and water for 90 days. After treatments, all animals were evaluated by behavioral tests to assess spatial memory and learning alongside other tests including the ferric reducing antioxidant power (FRAP), malondialdehyde, and histological examinations. The results showed that there are significant differences in the Morris water task and passive avoidance learning of behavioral tests and biochemical tests (FRAP and thiobarbituric acid reactive substances) between the two groups. The histological study indicated that the cell count of the hippocampus, the diameter of the lateral ventricle, and area of the corpus callosum in the raisin group changed in comparison with the control group but they were not significant. The results demonstrated that raisins significantly raise antioxidant levels in blood and promotes cognitive and motor performance in aging rats.