RESUMO
An iron(III) complex of thiacalix[4]arenetetrasulfonate attached to an anion-exchanger (Fe(3+)-TCASA-500) showed high peroxidase-like catalytic activity at pH 5 - 8 for the formation of quinoid dye, following the color reaction between 3-methyl-2-benzothiazolinone hydrazone (MBTH) and N-ethyl-N-(3-sulfopropyl)aniline (ALPS) in the presence of H2O2. This catalytic activity of Fe(3+)-TCASA-500 for the MBTH-ALPS system was applied for the spectrophotometric determination of H2O2, glucose, uric acid, and cholesterol. The calibration curves were linear in the concentration range from 1.0 to 15 µg of H2O2 in a 1.0-mL sample solution, and from 5.0 to 60 µg of glucose, 2.0 to 30 µg of uric acid, and 11.6 to 116 µg of cholesterol in a 0.5-mL sample solution. The apparent molar absorptivity of H2O2 was determined as 2.31 × 10(4) L mol(-1) cm(-1), which was about 70% of that by peroxidase under the same conditions. The determination method using Fe(3+)-TCASA-500 was applied for the determination of glucose and uric acid in both control sera I and II.
RESUMO
Four new eremophilane-type sesquiterpenes, culcitiolides A-D, were isolated from the stem of Senecio culcitioides Sch. Bip (Asteraceae). Their structures were established by detailed 2D NMR spectroscopic and single-crystal X-ray experiments. These compounds were assessed for inhibitory activity against nuclear factor kappaB (NF-kappaB). Culcitiolides C and D at 20 microM showed 97 and 100% inhibition of NF-kappaB activity, respectively.
Assuntos
Senécio/química , Sesquiterpenos/análise , Estrutura Molecular , Naftalenos/análise , Naftalenos/química , Sesquiterpenos Policíclicos , Sesquiterpenos/químicaRESUMO
(1S,3R)-1-Aminocyclopentane-1,3-dicarboxylic acid (ACPD), a potent agonist of metabotropic glutamate receptors, was synthesized from L-serine. The chiral quaternary center was constructed by C-H insertion of the alkylidenecarbene, this being generated by the reaction between lithiotrimethylsilyldiazomethane and the corresponding ketone.
