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961.
Bahadori F Topçu G Boğa M Türkekul A Kolak U Kartal M 《Natural product communications》2012,7(6):731-734
A new indole alkaloid, 11-hydroxypolyneuridine, was isolated from Vinca major subsp. major L. and the known indole alkaloids vallesiachotamine and isovallesiachotamine from Vinca minor L. This is the first report on the alkaloids of both Vinca species growing in Turkey; vallesiachotamine and isovallesiachotamine were isolated from a Vinca species for the first time. V. minor may be considered as a new source for these two alkaloids due to their occurrence in high amount in the aerial parts of the plant. The alkaloid extracts of the two Vinca species were found to have high lipid peroxidation inhibitory and DPPH radical scavenging activities. Anticholinesterase activity of the extracts was also very strong. 相似文献
962.
Zolfigol Mohammad Ali Khazaei Ardeshir Mokhlesi Mohammad Zare Abdolkarim Safaiee Maliheh Derakhshan‐Panah Fatemeh Keypour Hassan Ali Dehghani‐Firouzabadi Ahmad Merajoddin Maria 《中国化学》2012,30(2):345-352
Aluminum chloride (AlCl3) efficiently catalyzes one‐pot multicomponent condensation of enolizable ketones or alkyl acetoacetates with aldehydes, acetonitrile and acetyl chloride to afford β‐acetamido ketone or ester derivatives in high to excellent yields and in relatively short reaction times. Moreover, by this synthetic method, some novel β‐acetamido ketones and esters (i.e. one complex structure) are prepared. 相似文献
963.
One-pot, three-component coupling reactions of indole, aromatic aldehydes, and heteroaryl amines under solvent-free conditions lead to the formation of the corresponding novel 3-[(N-heteroaryl)(aryl)methyl]indoles in moderate to high yields. The key features of this multi-component reaction are the simple reaction procedure, no organic solvent or acid catalyst, and easy product separation without further purification. 相似文献
964.
The aim of this paper is a better comprehension of the encapsulation and interaction an anticancer drug Altretamine into BN nano ring [BNNR(9,9-5)] and AlN nano ring [AlNNR(9,9-5)]. The electronic and adsorption properties of the molecule Altretamine over the BNNR and AlNNR were theoretically studied in the solvent phase at the B3LYP/6-31G* level of theory for the first time. With the non-bonded interaction of Altretamine, the electronic properties of the BN and AlN nano-cages can be significantly changed. The electronic spectra of the Altretamine drug, complex BNNR/Altretamine and AlNNR/Altretamine in solvent water were calculated by Time Dependent Density Functional Theory (TD-DFT) for the investigation of adsorption effect. According to the natural bond orbital (NBO) results, the molecule Altretamine, BNNR and AlNNR play as both electron donor and acceptor at the complexes BNNR/Altretamine and AlNNR/Altretamine. On the other hand, the charge transfer is occurred between the bonding, antibonding or nonbonding orbitals in the molecule drug, BNNR and AlNNR. As a consequence, BNNR(9,9-5) and AlNNR(9,9-5) can be considered as a drug delivery system for the transportation of Altretamine as anticancer drug within the biological systems. 相似文献
965.
Ahmad Shaabani Fatemeh Hajishaabanha Hamid Mofakham Mojtaba Mahyari Bagher Lali 《Helvetica chimica acta》2012,95(2):246-254
A novel and efficient isocyanide‐based multicomponent reaction between alkyl or aryl isocyanides 1 , 2,3‐diaminomaleonitrile ( 2 ), naphthalene‐2,3‐diamines ( 6 ) or benzene‐1,2‐diamine ( 9 ), and 3‐oxopentanedioic acid ( 3 ) or Meldrum's acid ( 4 ) or ketones 7 was developed for the ecologic synthesis, at room temperature under mild conditions, of 1,6‐dihydropyrazine‐2,3‐dicarbonitriles 5a – 5f in H2O without using any catalyst, and of 3,4‐dihydrobenzo[g]quinoxalin‐2‐amine and 3,4‐dihydro‐3,3‐dimethyl‐quinoxalin‐2‐amine derivatives 8a – 8g and 10a – 10e , respectively, in the presence of a catalytic amount of p‐toluenesulfonic acid (TsOH) in EtOH, in good to excellent yields (Scheme 1). 相似文献
966.
Seyed Mojtaba Taghizadeh Yadollah YaminiMohammad Hosein Naeeni Fatemeh MohamadniaReza Sardeh Moghadam 《Polymer Testing》2012,31(2):297-303
A simple and efficient method based on hollow fiber protected headspace liquid-phase in conjunction with high performance liquid chromatography has been introduced for extraction and determination of three residual monomers (2-ethylhexyl acrylate (EHA), vinyl acetate (VA), glycidyl methacrylate (GM)) in polymer latex. Using this methodology, the analytes of interest extracted from a sample are led into organic solvent located inside the porous hollow fiber membrane. Initially, several experimental parameters were controlled and optimized and the optimum conditions were reached with 8 cm neatly cut hollow fibers containing heptanol, which were exposed to the headspace of a 12 mL sample solution containing 20% (w/v) NaCl thermostated at 110 °C and stirred at 800 rpm for 20 min. Finally, 20 μL of the extraction solution was withdrawn into a syringe and injected into HPLC for analysis. The calibration curves were linear (r2 ≥ 0.994) over the concentration range of 0.05-10 mg L−1 for VA and 0.02-10 mg L−1 for other analytes. The relative standard deviation (RSD%) for three-replicate extractions and measurements was below 8.6%. The limits of detection of this method for quantitative determination of the analytes were found within the range of 0.005 to 0.011 mg kg−1 with the enrichment factors within the 5-164 range. The method was successfully applied for determination of residual monomers in polymer latex. 相似文献
967.
Ali Reza Keshtkar Fatemeh Kafshgari Mohammad Ali Mousavian 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(2):501-512
Simultaneous biosorption of uranium(VI) and nickel(II) ions onto Ca-pretreated Cystoseira indica biomass was studied and compared with single uranium or nickel biosorption in a fixed-bed column. Results of single biosorption
showed the breakthrough and exhaustion time increase with the increase of the flow rate and inlet metal concentration for
both metal ions. Also, it was observed that there was an optimum flow rate of 1.4 mL min−1 (surface loading of 0.792 cm min−1) for both metal ions in the column. Results from both single and binary systems showed the adsorption capacity of C. indica for both metal ions increases with the increasing inlet concentration of each component and C. indica had a stronger affinity for uranium than nickel ions. The binary system results showed that the presence of the second component
affected the adsorption of the first one by C. indica so the antagonistic action was observed. Also, the inhibitory effect of uranium ions on the nickel adsorption was greater
than nickel ions on the uranium adsorption. The uranium and nickel breakthrough curves under different conditions were described
by the Thomas, Yoon-Nelson and Yan models. Among these models, the Yan model appeared to describe the experimental results
better. 相似文献
968.
The longest path problem is a well-known NP-hard problem and so far it has been solved polynomially only for a few classes of graphs. In this paper, we give a linear-time algorithm for finding a longest path between any two given vertices in a rectangular grid graph. 相似文献
969.
We study spin dependent transport through a magnetic bilayer graphene nanojunction configured as a two-dimensional normal/ferromagnetic/normal structure where the gate voltage is applied on the layers of ferromagnetic graphene. Based on the four-band Hamiltonian, conductance is calculated by using the Landauer-Buttiker formula at zero temperature. For a parallel configuration of the ferromagnetic layers of bilayer graphene, the energy band structure is metallic and spin polarization reaches its maximum value close to the resonant states, while for an antiparallel configuration the nanojunction behaves as a semiconductor and there is no spin filtering. As a result, a huge magnetoresistance is achievable by altering the configurations of ferromagnetic graphene around the band gap. 相似文献
970.