Paeonins A and B,lipoxygenase inhibiting monoterpene galactosides from Paeonia emodi

Paeonins A and B, new monoterpene galactosides have been isolated from the chloroform-soluble fraction of the roots of Paeonia emodi and showed potent lipoxygenase inhibitory activity. The structures of 1 and 2 have been assigned on the basis of spectral analysis including one- and two-dimensional NMR techniques.     

Highly oxygenated triterpenes from the roots of Atropa acuminata

Two new oleanane triterpenes; 2alpha,3alpha,24-trihydroxyolean-12-ene-28,30-dioic acid ([structure: see text]) and 2alpha,3alpha,24,28-tetrahydroxyolean-12-ene ([structure: see text]) have been isolated from the roots of Atropa acuminata. Anti-oxidant p-hydroxyphenethyl trans-ferulate ([structure: see text]), beta-sitosterol-3-O-beta-D-glucopyranoside ([structure: see text]) and oleanolic acid ([structure: see text]) have also been reported for the first time from this species. The structures were determined by spectroscopic studies including 2D-NMR.     

Selective colorimetric and fluorometric sensing of Cu(II) by iminocoumarin derivative in aqueous buffer

A new iminocoumarin based receptor L (C(27)H(26)N(4)OS) is synthesized with pyridyl and benzothiazolyl functionality. Synthesis of L is easy and it is isolated in good yield. L shows a selective and distinct color change from yellow to orange with Cu(2+) over Li(+), Na(+), Ca(2+), Mg(2+), Cr(2+), Mn(2+), Fe(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Pb(2+), and Ag(+) whereas a slight change in color is also observed in the case of Hg(2+) but L shows selective fluorescent quenching only in the presence of Cu(2+) in aqueous HEPES buffer (pH 7.0). The naked eye detection limit of Cu(2+) is determined at 2 μM whereas an emission experiment shows a lower detection limit at 200 nM. Selectivity studies of L in presence of 50 equivalents of other ion(s) by emission experiment show no interference toward the detection of 1 equivalent of Cu(2+). Both UV-Vis and fluorescence studies in the presence of Cu(2+)-salts of different counter anions with various sizes and shapes (Cl(-), ClO(4)(-), NO(3)(-), CF(3)SO(3)(-), SO(4)(2-) and BF(4)(-)) show almost similar spectral output in buffer media irrespective of the nature of the counter anions. The detailed UV-Vis and fluorescence titration experiments suggest the existence of both 1:1 and 2:1 (L:Cu(2+)) complexation stoichiometry and EPR study shows d(x(2)-y(2)) ground state of the Cu(II) centre in the complex. Furthermore the formation of a mononuclear [Cu(L)(CH(3)CN)].2ClO(4) complex and the flexible conformation of L in the solid state are confirmed by the single-crystal X-ray structural study.     

A new three-component reaction: green synthesis of novel isoindolo[2,1-a]quinazoline derivatives as potent inhibitors of TNF-α

Concurrent construction of five and six membered fused N-heretocyclic ring was achieved via a conceptually new three-component reaction affording 6,6a-dihydroisoindolo[2,1-a]quinazoline-5,11-diones as novel inhibitors of TNF-αin vitro. This represents one of the few examples of direct TNF-α inhibition by small molecules.     

Effect of Adenine Sulphate Interaction on Growth and Development of Shoot Regeneration and Inhibition of Shoot Tip Necrosis Under In Vitro Condition in Adult Syzygium cumini L.—a Multipurpose Tree

An efficient method for cloning Syzygium cumini (above 40 years old) through mature nodal segments has been successfully developed and that could be exploited for large-scale production of this valuable multipurpose tree. Nodal segments from mature tree were taken as explants and cultured on MS basal medium with different cytokinins (BA, Kin, AdS). The application of BA proved to be the best responsive cytokinin for the induction of shoot buds and shoots, but the proliferated shoots exhibited slower and stunted growth accompanied with abscission of leaves and shoot tip necrosis (STN). The problem of leaf abscission and STN was considerably reduced by the application of an adjuvant, adenine sulphate (AdS) in the optimal medium which led to the production of a maximum of 14 shoots. Further improvement in shoot bud regeneration and improved growth pattern of the regenerating tissue was obtained on the media comprised of MS?+?BA (10 μM)?+?GA₃ (2.5 μM). A total number of 15 shoots with mean shoot length of 5.9 cm was obtained. The healthy elongated shoots were then rooted on MS basal augmented with NAA (5 μM). The plantlets obtained were healthy and were successfully acclimatized and transferred under field condition with 70 % survival rate.     

Interaction of Fluorescently Labeled Triethyleneglycol and Peptide Derivatives with β‐Cyclodextrin

A triethyleneglycol (TEG) chain, a linear peptide, and a cyclic peptide labeled with 7‐methoxycoumarin‐3‐carboxylic acid (MC) and 7‐diethylaminocoumarin‐3‐carboxylic acid (DAC) were used to thoroughly study Förster resonance energy transfer (FRET) in inclusion complexes. ¹H NMR evidence was given for the formation of a 1:1 inclusion complex between β‐cyclodextrin (β‐CD) and the fluorophore moieties of model compounds. The binding constant was 20 times higher for DAC than for MC derivatives. Molecular modeling provided additional information. The UV/Vis absorption and fluorescence properties were studied and the energy transfer process was quantified. Fluorescence quenching was particularly strong for the peptide derivatives. The presence of β‐CDs reduced the FRET efficiency slightly. Dye‐labeled peptide derivatives can thus be used to form inclusion complexes with β‐CDs and retain most of their FRET properties. This paves the way for their subsequent use in analytical devices that are designed to measure the activity of matrix metalloproteinases.     

双金属镍-锰／γ-Al2O3催化剂对甲烷二氧化碳重整反应的影响

用浸渍法制备γ-Al2O3负载的Ni-Mn双金属催化剂．在500-700。C按照17：17：2的C02／CHa／N2比例,以36mL／min的载气流速进行甲烷二氧化碳重整反应,利用甲烷二氧化碳的转化率、生成的合成气H2／CO比例以及长期稳定性等指标评价了催化剂的催化性能．实验表明,添加Mn提高催化性能并使双金属催化剂的稳定性更高,比单金属催化剂更好地抑制焦炭生成,Mn最合适的添加量为0．5wt％．通过BET、C02-TPD、TGA、XRD、SEM、EDX和FTIR各种技术对催化剂进行了表征．