Search results for "Heterocyclic compound"
showing 10 items of 382 documents
Relaxant effects of flavonoids on the mouse isolated stomach: structure-activity relationships.
2008
Flavonoids are a large heterogeneous group of benzo-gamma-pyrone derivatives, which are abundantly present in our diet. In this study we investigated the effects of six flavonoids (apigenin, genistein, quercetin, rutin, naringenin and catechin) on the gastric tone in mouse isolated stomach. The mechanical activity was recorded as changes of intraluminal pressure. All flavonoids tested produced a concentration-dependent relaxation, which was reversible after washout. The relative order of potency of the flavonoids was apigenin> or =genistein>quercetin>naringenin> or =rutin>catechin. Analysis of the chemical structure showed that the relaxant activity was progressively diminished by the prese…
Influence of anti-inflammatory flavonoids on degranulation and arachidonic acid release in rat neutrophils.
1994
We assessed the effects of 24 flavonoid derivatives, reported as anti-inflammatory, on lysosomal enzyme secretion and arachidonic acid release in rat neutrophils. Amentoflavone, quercetagetin- 7-O -glucoside, apigenin, fisetin, kaem pferol, luteolin and quercetin were the most potent inhibitors of β-glucuronidase and lysozyme release. The first com pound was also able to inhibit basal release. These flavonoids besides chrysin and to a reduced extent, naringenin, significantly inhibited arachidonic acid release from membranes. A correlation between degranulation and arachidonic acid release was found for this series of compounds. Structureactivity relationships and implications for the anti-…
Harmful and Protective Effects of Phenolic Compounds from African Medicinal Plants
2014
Phenolic phytochemicals include flavonoids, phenolic acids, tannins, lignans, coumarins, quinones, xanthones, cucurmin, and several other plant compounds owing hydroxyl group bonded directly to an aromatic hydrocarbon group. In plants, they play a variety of protective effects against abiotic stresses like UV light or biotic stresses such as predator and pathogen attacks. This role is exploited by humans to treat several ailments including bacterial, fungal, protozoal and viral infections, inflammation, cancer, and diabetes. Numbers of them are known to display direct protection on cells or organs in humans and animals. In contrast, some of others rather have harmful or toxic effects. In th…
Design of Bimodal Ligands of Neurotensin Receptor 1 for Positron Emission Tomography Imaging and Fluorescence-Guided Surgery of Pancreatic Cancer
2020
International audience; Neurotensin receptor 1 (NTSR1) is overexpressed in most human pancreatic ductal adenocarcinomas. It makes it an attractive target for the development of pancreatic cancer imaging agents. In this study, we sought to develop a bimodal PET-fluorescent imaging agent capable of specifically targeting these receptors. Starting from the structure of a known NTSR1 agonist, a series of tracers was synthesized, radiometalated with gallium-68 and evaluated in vitro and in vivo, in mice bearing an AsPC-1 xenograft. PET imaging allowed us to identify the compound [ 68 Ga]Ga-NODAGA-Lys(Cy5**)-AEEAc-[Me-Arg 8 , Tle 12 ]-NT(7-13) as the one with the most promising biodistribution pr…
Heterocycles from α-aminonitriles.
2014
Owing to their various modes of reactivity, α-aminonitriles represent versatile building blocks for the construction of a wide range of nitrogen heterocycles. The present Concept article focuses on synthetic methodologies using their bifunctional nature which is the basis of their reactivity as α-amino carbanions and as iminium ions. Reactions exclusively taking place on either the amine or on the nitrile moiety will not be considered.
A Versatile Synthesis of Fluorinated Uracils in Solution and on Solid-Phase.
2004
[reaction: see text] An efficient and convenient two-step synthesis of new fluorinated uracils is described. The first step involves the condensation of an ester enolate with a fluorinated nitrile to furnish fluorinated beta-enamino esters. In turn, these compounds react with organic isocyanates or isothiocyanates to give C-6 fluorinated uracils or thiouracils, respectively, in excellent yields. This synthesis has been successfully adapted to solid-phase conditions with high diversity, thereby facilitating the creation of small (thio)uracil libraries.
Concise asymmetric synthesis of Linezolid through catalyzed Henry reaction
2013
A new asymmetric synthesis of the antibiotic Linezolid was performed through a copper-catalyzed Henry reaction as the key step. The use of camphor-derived aminopyridine ligands helped to improve the yields of the chiral precursor and to obtain Linezolid in good overall yield and enantiomeric excess.
Mycobiota and mycotoxin producing fungi from cocoa beans.
2008
The present study reports on the natural mycobiota occurring in cocoa beans, paying special attention to the incidence of fungal species that are potential producers of mycotoxins. The results show that predominant fungi were different species of the genus Aspergillus belonging to section Flavi and Nigri. Of the 214 strains of Aspergillus section Flavi collected from cocoa beans, 120 were identified as A. flavus and 94 as A. tamarii. Of Aspergillus section Nigri 138 strains were isolated, with 132 belonging to A. niger aggregate and 6 to A. carbonarius species. Potential ability to produce aflatoxins (AFs) B1, B2, G1 and G2, cyclopiazonic acid (CPA) and ochratoxin A (OTA) was studied by iso…
Plerixafor is effective and safe for stem cell mobilization in heavily pretreated germ cell tumor patients.
2010
Up to 10% of germ cell tumor patients require salvage high-dose chemotherapy with stem cell support, achieving cure rates in the range of 10-60%. Stem cell mobilization may be difficult in these patients because of multiple lines of treatment known to seriously hamper stem cell recovery. Plerixafor significantly enhances the success of the CD34+ cell harvest, even in cases where prior mobilization attempts have failed. Six germ cell tumor patients provided informed consent and were included in the compassionate use program. All patients were heavily pretreated, with a median of 3.5 prior lines of therapy. All failed prior mobilization with G-CSF in combination with chemotherapy. Five patien…
Gemcitabine plus sorafenib versus gemcitabine alone in advanced biliary tract cancer: a double-blind placebo-controlled multicentre phase II AIO stud…
2014
Background: Since sorafenib has shown activity in different tumour types and gemcitabine regimens improved the outcome for biliary tract cancer (BTC) patients, we evaluated first-line gemcitabine plus sorafenib in a double-blind phase II study. Patients and methods: 102 unresectable or metastatic BTC patients with histologically proven adenocarcinoma of gallbladder or intrahepatic bile ducts, Eastern Cooperative Oncology Group (ECOG) 0–2 were randomised to gemcitabine (1000 mg/m2 once weekly, first 7-weeks + 1-week rest followed by once 3-weeks + 1-week rest) plus sorafenib (400 mg twice daily) or placebo. Treatment continued until progression or unacceptable toxicity. Tumour samples were p…