Search results for "Pyrrole"

Pyrrolo[2,1-d][1,2,3,5]tetrazine-4(3H)-ones, a new class of azolotetrazines with potent antitumor activity.

2003

Pyrrolo[2,1-d][1,2,3,5]tetrazinones 10a-o, compounds that hold the deaza skeleton of the antitumor drug temozolomide, were prepared by reaction of 2-diazopyrroles 9 and isocyanates. Such a synthetic route represents, among those leading to azolotetrazinones reported so far, the only possible one since attempts to cyclize to the title ring system 2-amino-1-carbamoylpyrroles 11 or the mono substituted 2-triazenopyrrole 12 failed. Compounds 10 were screened at the National Cancer Institute (NCI) for their activity against a panel of about 60 human tumor cell lines. Most of them possess remarkable antineoplastic activity having GI(50) values in the low micromolar or sub-micromolar range and rea…

Halothane inhibits endothelium-dependent relaxation elicited by acetylcholine in human isolated pulmonary arteries.

1997

This study examined whether a clinically relevant concentration of the volatile anaesthetic halothane modifies the endothelium-dependent relaxation produced by acetylcholine (3 nM-10 microM), histamine (1 pM-0.1 microM) and anti-human immunoglobulin E (1:1000) in human isolated pulmonary arteries submaximally precontracted with noradrenaline. An inhibitor of nitric oxide formation, N(G)-nitro-L-arginine (100 microM), attenuated acetylcholine-induced relaxation but failed to inhibit histamine- and anti-human immunoglobulin E-induced relaxation. Indomethacin (2.8 microM, a cyclooxygenase inhibitor) preferentially reduced the relaxation to histamine and anti-human IgE. Halothane (2%) significa…

SYNTHESIS OF NEW OLIGOPEPTIDE PYRROLE DERIVATIVES

2008

Synthesis of the new oligopeptide pyrrole derivative isonetropsin and its one pyrrole unit analogue

2013

We have designed and synthesized isonetropsin and its one pyrrole unit analogue in which the amine and carbonyl groups have been switched in positions 2 and 4, respectively instead of 4 and 2 positions of the natural antibiotic netropsin.

Efficacy and safety of regorafenib for advanced gastrointestinal stromal tumours after failure of imatinib and sunitinib (GRID): an international, mu…

2013

Contains fulltext : 118365.pdf (Publisher’s version ) (Closed access) BACKGROUND: Until now, only imatinib and sunitinib have proven clinical benefit in patients with gastrointestinal stromal tumours (GIST), but almost all metastatic GIST eventually develop resistance to these agents, resulting in fatal disease progression. We aimed to assess efficacy and safety of regorafenib in patients with metastatic or unresectable GIST progressing after failure of at least imatinib and sunitinib. METHODS: We did this phase 3 trial at 57 hospitals in 17 countries. Patients with histologically confirmed, metastatic or unresectable GIST, with failure of at least previous imatinib and sunitinib were rando…

Ferrocenyl (P,N)-diphosphines incorporating pyrrolyl, imidazolyl or benzazaphospholyl moieties: Synthesis, coordination to group 10 metals and perfor…

2013

Abstract Three novel symmetrical ferrocenyl diphosphines with tertiary phosphorus atoms holding respectively nitrogen-containing heterocyclic derivatives of pyrrole, imidazole and benzazaphosphole were synthesized and characterized. Up to now, integration of heteroaromatic fragments, or more generally hetero-cycles, as substituents on the tertiary phosphines of symmetrical ferrocenyl diphosphines has been limited to the furyl motif. Their coordination to palladium and platinum group 10 transition metals was exemplified, and analyzed using single crystal X-ray diffraction. The performances obtained in palladium-catalyzed copper-free Sonogashira and Suzuki cross-coupling reactions using bromo…

SYNTHESIS OF PYRROLO[3,2-H]QUINOLINONES WITH GOOD PHOTOCHEMOTHERAPEUTIC ACTIVITY AND NO DNA DAMAGE

2010

In the search for new photochemotherapeutic agents, a series of derivatives of the ring system pyrrolo[3,2-h]quinoline--bioisosters of the angular furocoumarin angelicin--were synthesized through a four-step synthetic approach, in reasonable overall yields. Eight of the synthesized derivatives showed a remarkable phototoxicity against a panel of four human tumor cell lines and a great dose UV-A dependence, reaching IC₅₀ values at submicromolar level. The mode of cellular death photoinduced by pyrrolo[3,2-h]quinolines was evaluated through a series of flow cytometric analysis and other tests were performed to clarify their mechanism of action.

Pyrrolo[1,2-f]phenanthridines and related non-rigid analogues as antiviral agents.

2002

Abstract The pyrrolo[1,2- f ]phenanthridines 8 – 22 and the corresponding non-rigid analogues 23 – 41 were synthesised and their ability to inhibit the replication of HIV-1 was tested. Only the polycyclic derivatives 10 , 11 , and 13 showed a weak anti -HIV activity, whereas several pyrrolo-phenanthridines ( 8 , 10 , 16 – 18 ) were found to stimulate the multiplication of MT-4 cells at low concentrations. Derivative 10 demonstrated to possess the unique property of stimulating the multiplication of lymphocytes joined to HIV inhibition.

Influence of the electrodeposition conditions on the energetics of polypyrrole thin films

2008

The influence of the solvent used for the electrodeposition and that of the dopant anion on the energetics of electrochemically grown polypyrrole were studied by means of a non-destructive optical technique: Photocurrent Spectroscopy. Polypyrrole films doped with the same anion and grown in different solvents, both aqueous and non- aqueous, show the same HOMO-LUMO gap and the same Fermi level location in respect to HOMO. Polypyrrole films doped with different anions in aqueous solutions, present different values of indirect band gap and flat band potential, indicating that dopant anion influences both the defects band and the Fermi level locations.

Photoelectrochemical Bisphenol S Sensor Based on ZnO‐Nanoroads Modified by Molecularly Imprinted Polypyrrole

2019

Molecularly imprinted polymers are important tools for the design of sensors and other molecular recognition based analytical systems. In this paper the development of a photoelectrochemical sensor for selective bisphenol determination is reported. The sensor is based on a glass/ZnO/MIP‐Ppy structure consisting of glass modified by a ZnO layer (glass/ZnO), which is functionalized by molecularly imprinted conducting polymer polypyrrole (MIP‐Ppy). The sensitivity of the sensor to bisphenol is in the range of 0.7–12.5 µm. Selectivity tests to other bisphenolic compounds are performed. Some aspects of a photoinduced response mechanism in glass/ZnO/MIP‐Ppy nanostructures are predicte…