Search results for "Rite"

Acylated triterpene saponins from the roots of Securidaca longepedunculata.

2009

Abstract Four triterpene saponins , 3- O -β- d -glucopyranosylpresenegenin 28- O -β- d -apiofuranosyl-(1 → 3)-β- d -xylopyranosyl-(1 → 4)-[β- d -apiofuranosyl-(1 → 3)]-α- l -rhamnopyranosyl-(1 → 2)-{4- O -[( E )-3,4,5-trimethoxycinnamoyl]}-β- d -fucopyranosyl ester, 3- O -β- d -glucopyranosylpresenegenin 28- O -β- d -apiofuranosyl-(1 → 3)-β- d -xylopyranosyl-(1 → 4)-[β- d -apiofuranosyl-(1 → 3)]-α- l -rhamnopyranosyl-(1 → 2)-[(6- O -acetyl)-β- d -glucopyranosyl-(1 → 3)]-{4- O -[( E )-3,4,5-trimethoxycinnamoyl]}-β- d -fucopyranosyl ester, 3- O -β- d -glucopyranosylpresenegenin 28- O -β- d -apiofuranosyl-(1 → 3)-β- d -xylopyranosyl-(1 → 4)-[β- d -apiofuranosyl-(1 → 3)]-α- l -rhamnopyranosyl-(…

In vivo anti-inflammatory activity of saponins from Bupleurum rotundifolium

2001

Seven oleanane-type triterpene saponins were isolated from the methanolic extract of the aerial parts of Bupleurum rotundifolium. They were identified on the basis of their spectral data as 3-O-[alpha-L-rhamnopyranosyl (1--2)-beta-D-glucopyranosyl (1--2)-beta-D-glucopyranosyl]-28-O-[beta-D-glucopyranosyl (1--2)-beta-D-glucopyranosyl] echinocystic acid (saponin 1), 3-O-[alpha-L-rhamnopyranosyl (1--2)-beta-D-glucopyranosyl (1--2)-beta-D-fucopyranosyl] 11-methoxy-primulagenin A (saponin 2), rotundioside E (saponin 3), rotundioside F (saponin 4), 3beta-sulfate, 28-O-[beta-D-glucopyranosyl (1--6)-beta-D-glucopyranosyl (1--2)-beta-D-glucopyranosyl (1--2)-beta-D-glucopyranosyl] ester of primulagen…

Mechanical, structural and magnetic properties of polypropylene/iron ferrite magnetic nanocomposites

2012

In this research, composites of polypropylene (PP) and a relatively small concentrations of iron ferrite (Fe3O4) nanopowder equal to 2, 5 and 10 wt.% have been made. An methacrylate monomer 2,2'-bis-(4-(2-methylprop-2-enoyloxy)phenyl)- propane (BAD) was added at a small amount (3 wt.%) to part of the composites during the thermoplastic mixing. The BAD has been used as a compatibilizing agent on the phase interaction between the filler and the matrix of polypropylene. It has been found that composites have adjustable mechanical, structural and magnetic properties dependent on the content of magnetic filler. Increase of concentration of ferrite particles affects a notable increase of elastic …

Interplays between nitric oxide and reactive oxygen species in cryptogein signalling

2014

The cellular messenger nitric oxide (NO) has many functions in plants. In this study, we investigated its interplays with Reactive Oxygen Species (ROS) in the defense responses triggered by the elicitin cryptogein produced by the oomycete Phytophthora cryptogea. The production of NO induced by cryptogein in tobacco cell suspensions was partly regulated through a ROS-dependent pathway involving the NADPH oxidase NtRBOHD. In turn, NO down-regulated the level of H2O2 derived from NtRBOHD activity. Both NO and ROS synthesis appeared to be under the control of two redundant isoforms of histone deacetylases of type 2 acting as negative regulators of cell death. Occurrence of an interplay between …

‘Interrupted’ diazotization of 3-aminoindoles and 3-aminopyrroles

2014

Abstract ‘Interrupted’ diazotization of 3-aminoindoles and 3-aminopyrroles, achieved by quenching with cold water immediately after the addition of nitrite, led, in good yields, to stable compounds whose structures were identified to be the diazonium species with nitrate as the counter ion, which show no saline character.

2015

The rationale of the study was two-fold: (i) develop a functional synthetic model of the Cytochrome c oxidase (CcO) active site, (ii) use it as a convenient tool to understand or predict the outcome of the reaction of CcO with ligands (physiologically relevant gases and other ligands). At physiological pH and potential, the model catalyzes the 4-electron reduction of oxygen. This model was immobilized on self-assembled-monolayer (SAM) modified electrode. During catalytic oxygen reduction, electron delivery through SAMs is rate limiting, similar to the situation in CcO. This model contains all three redox-active components in CcO's active site, which are required to minimize the production o…

Uncoupling of Endothelial Nitric Oxide Synthase in Cardiovascular Disease and its Pharmacological Reversal

2010

Publisher Summary This chapter discusses the role of oxidative stress in vascular dysfunction and atherogenesis, and strategies for its prevention. Endothelial dysfunction and oxidative stress have been identified as a common denominator of many cardiovascular risk factors. They support pro-inflammatory, prothrombotic, proliferative, and vasoconstrictor mechanisms that are involved in the initiation, progression, and complications of atherosclerosis. The pathophysiologic causes of oxidative stress involve changes in a number of different enzyme systems. Increased production of ROS by uncoupled eNOS is likely to contribute significantly to vascular oxidative stress and endothelial dysfunctio…

30-Norfriedelane triterpenes from the stem bark ofCaloncoba glauca

1992

Abstract The stem bark of Caloncoba glauca has yielded three friedelane triterpenes of which two are characterized by the loss of C-30 and the presence of a C-27, C-15 lactone. They were identified, with considerable use of long-range C H coupling studies, as the known compound trichadonic acid (3-oxofriedelan-27-oic acid) and two new 30-norfriedelane derivatives, 3,27-dioxo-30-norfriedelan-20(29)-en-27,15α-lactone (caloncobalactone) and 3,27-dioxo-21β-hydroxy-30-norfriedelan-20(29)-en-17,15α-lactone (21β-hydroxycaloncoba lactone).

Friedelane triterpenes from the stem bark of Caloncoba glauca

1993

Further investigation of the stem bark of Caloncoba glauca has yielded three minor (D:A)-friedo-oleanane derivatives. These have been identified, on the basis of NMR studies, as the known compound kokoonol [3-oxo-(D:A)-friedo-olean-27-ol] and the novel natural products kokoonal [3-oxo-(D:A)-friedo-olean-27- al] and 3β,21β-dihydroxy-30-nor-(D:A)-friedo-olean-27-oic acid.

Polyacanthoside A, a new oleanane-type triterpenoid saponin with cytotoxic effects from the leaves of Acacia polyacantha (Fabaceae)

2018

The chemical investigation of the leaves and stem bark of Acacia polyacantha (Fabaceae) led to the isolation of a new oleanane-type triterpenoid saponin named polyacanthoside A 1 together with fifteen known compounds. Their structures were established from spectral , mainly HRESIMS, 1D NMR and 2D NMR and by comparison with literature data. The cytotoxicity of compound 1 and the analogues 8 as well as doxorubicin was determined in a panel of 9 cancer cell lines including sensitive and drug resistant phenotypes. Unlike the analogue 8, compound 1 as well as doxorubicin displayed cytotoxic effects in all the 9 tested cancer cell lines with IC50 values ranged from 8.90 μM (towards CCRF-CEM leuke…