fe3o4 magnetic nanoparticles were synthesized by co-precipitation of fe2+ and fe3+ in aqueous naoh. then silica was coated on the obtained nanoparticles and the whole composite was functionalized with chlorosulfonic acid in ch2cl2. the obtained nanocomposite (fe3o4@sio2-so3h) was characterized by ft-ir, vsm and xrd techniques and was used as an efficient catalyst in condensation reaction of ind...

a simple and efficient method for synthesis of tetrahydropyrimido[4,5-b]quinoline derivatives via three component reaction of aromatic aldehydes, dimedone and 6-amino uracil derivatives using a catalytic amount of sulfonic acid functionalized nanoporous silica (sba-15-pr-so3h) is described. the advantages of this method are easy and clean work-up, high yield, mild reaction condition, reusable c...

Fe3O4 magnetic nanoparticles were synthesized by co-precipitation of Fe2+ and Fe3+ in aqueous NaOH. Then silica was coated on the obtained nanoparticles and the whole composite was functionalized with chlorosulfonic acid in CH2Cl2. The obtained nanocomposite (Fe3O4@SiO2-SO3H) was characterized by FT-IR, VSM and XRD techniques and was used as an efficient catalyst in condensation reaction of ind...

A new efficient method for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones and spiroquinazolinones via a condensation reaction of aldehydes and ketones with anthranilamide in the presence of nano Fe3O4@SiO2-SO3H as catalyst in ethanol has been described. The reactions are completed in short times, and the corresponding dihydroquinazolinones are produced with high yields. The present procedure...

The cytotoxic effects of thiopurine drugs are mostly exerted through the formation of thioguanine nucleotide and its subsequent incorporation into DNA. The 6-thioguanine (6-TG) in DNA can be converted to S6-methylthio-2-aminopurine (2-AP-6-SCH3) and 2-aminopurine-6-sulfonic acid (2-AP-6-SO3H) upon reaction with S-adenosyl-L-methionine and irradiation with UVA light, respectively. Here we prepar...

Peptide growth factors were isolated from conditioned medium derived from rice (Oryza sativa L.) suspension cultures and identified to be a sulfated pentapeptide [H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-Gln-OH] and its C-terminal-truncated tetrapeptide [H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-OH]. These structures were identical to the phytosulfokines originally found in asparagus (Asparagus officinalis L.) mesoph...

Sodium praseodymium silicate glasses of nominal composition 0.3Na2O xPr2O3 (0.7 x)SiO2, where 0pxp0:10; have been studied by magnetisation and X-ray photoelectron spectroscopy (XPS). The magnetisation data fail to collapse to a single curve in the M versus H=T representation for all values of x and the spread increases with x; indicating an increase in the magnetic exchange interaction. The M v...

Thermally excited luminescence from rare-earth element doped SiO2 fibers were studied for the fiber-optic thermometer application in high temperature. Thermal radiation similar to the black body radiation was observed in visible light region from the SiO2 fibers doped with Y, La, Ce, Pr, Eu, Tb and Lu. Visible light radiation peaks due to f-f transitions of rare-earth ions were clearly observed...