Search results for "Azine"
showing 10 items of 1589 documents
Stochastic dynamics of leukemic cells under an intermittent targeted therapy
2009
The evolutionary dynamics of cancerous cell populations in a model of Chronic Myeloid Leukemia (CML) is investigated in the presence of an intermittent targeted therapy. Cancer development and progression is modeled by simulating the stochastic evolution of initially healthy cells which can experience genetic mutations and modify their reproductive behavior, becoming leukemic clones. Front line therapy for the treatment of patients affected by CML is based on the administration of tyrosine kinase inhibitors, namely imatinib (Gleevec) or, more recently, dasatinib or nilotinib. Despite the fact that they represent the first example of a successful molecular targeted therapy, the development o…
A linear open-chain piperazine-pyridine ligand and its meso-helical Co complex
1998
Abstract An oligomeric ligand (HPPy) 2 P, N , N ′-bis[2-(6-( N -( N ′-(2-hydroxyethyl)piperazinyl)methyl)]piperazine, was designed to resemble structurally open-chain aza-crowns. Owing to the all- trans configuration of piperazine and pyridine free electron pairs, it should adopt a near linear overall structure in solvent. Theoretical calculations at ab initio level confirm the overall linear structure of free ligand. The crystal structure of the complex [(HPPy) 2 P][Co(NO 3 ) 2 ] 2 shows a contraction from ∼3 to 2 nm structure. Each coordination site creates either a Δ or Δ configuration around the metal ion, thus causing a ligand with an even number of coordination centres to be meso -hel…
Beyond Pseudo‐natural Products: Sequential Ugi/Pictet‐Spengler Reactions Leading to Steroidal Pyrazinoisoquinolines That Trigger Caspase‐Independent …
2021
In this work, we describe how stereochemically complex polycyclic compounds can be generated by applying a synthetic sequence comprising an intramolecular Ugi reaction followed by a Pictet-Spengler cyclization on steroid-derived scaffolds. The resulting compounds, which combine a fragment derived from a natural product and a scaffold not found in nature. are both structurally distinct and globally similar to natural products at the same time, and interrogate an alternative region of the chemical space. One of the new compounds showed significant antiproliferative activity on HepG2 cells through a caspase-independent cell-death mechanism, an appealing feature when new antitumor compounds are…
Membrane D-lactate oxidase in Zymomonas mobilis: evidence for a branched respiratory chain.
1998
Respiratory chain composition of the ethanol-producing bacterium Zymomonas mobilis was studied. Its membrane D-lactate oxidase was characterised. With NADH, but not D-lactate as substrate, a cytochrome o-like component was seen in CO difference spectra. Chlorpromazine specifically inhibited reduction of cytochrome d, while myxothiazol eliminated the cytochrome o-like features in CO difference spectra. It is suggested that electrons from NADH are distributed between branches terminated by the cytochrome o-like component, cytochrome a, and cytochrome d. With D-lactate, electrons are transported to cytochrome a, or an unidentified CN(-)-sensitive oxidase, and cytochrome d.
11H‑Pyrido[3′,2′:4,5]pyrrolo[3,2‑c]cinnoline and Pyrido[3′,2′:4,5]pyrrolo[1,2‑c][1,2,3]benzotriazine: Two New Ring Systems with Antitumor Activity
2014
Derivatives of new ring systems 11H-pyrido[3',2':4,5]pyrrolo[3,2-c]cinnoline and pyrido[3',2':4,5]pyrrolo[1,2-c][1,2,3]benzotriazine have been prepared from the key intermediates 2-(1H-pyrrolo[2,3-b]pyridin-2-yl)anilines in excellent yields (94-99%) and screened by the National Cancer Institute (Bethesda, MD) on about 60 human tumor cell lines derived from nine cancer cell types. The tested compounds exhibited antiproliferative activity against all the human cell lines, showing comparable MG_MID (mean graph midpoint) values in the range of 0.74-1.15 μM. A particular efficacy was observed against the leukemia subpanel (GI50 = 0.73-0.0090 μM). Flow cytometric analysis of the cell cycle demons…
Synthesis and cytotoxicity of 6,11-Dihydro-pyrido- and 6,11-Dihydro-benzo[2,3-b]phenazine-6,11-dione derivatives
2003
6,11-Dihydro-pyrido[2,3-b]phenazine-6,11-diones and 6,11-dihydro-benzo[2,3-b]phenazine-6,11-diones were synthesized from 6,7-dichloro-5,8-quinolinedione and 2,3-dichloro-1,4-naphthoquinone. The study on the cytotoxicity on these products revealed that the pyridophenazinediones, tetracyclic heteroquinone analogues with three nitrogen atoms exhibited a high cytotoxicity on several human tumor cell lines. Compound 9c and 9e showed in vitro antitumor activity comparable or superior to doxorubicin against the human ovarian tumor cells (SK-OV-3) and the human CNS cells (XF 498). The IC(50) value for compound 9e was 0.06 microM against the human CNS cells (XF 498), which was 2.6 times higher than …
Synthesis and in vitro antileukemic activity of new 4-triazenopyrazole derivatives
2003
Several new 4-(3,3-dimethyltriazeno)-5-benzamidopyrazole derivatives were prepared by reacting 4-diazo-5-benzamidopyrazole derivatives with dimethylamine. The compounds were tested at 10 microM for their vitro antileukemic activity against K562 (Human chronic myelogenous leukemia) and Raji (human Burkitt limphoma ) cell lines. Dacarbazine and methotrexate were used for comparative purpose. The 3-methyl-4-(3,3-dimethyltriazeno)-5-(substituted benzamido)pyrazoles, bearing the pyrazole nucleus free at 1 position, resulted more active than the 1-(substituted phenyl)-3-methyl-4-(3,3-dimethyltriazeno)-5-benzamidopyrazoles. Dacarbazine at 10 microM showed no activity in the above tests. The observ…
[Fe(TPT)(2/3){M(I)(CN)2}2]⋅nSolv (M(I) = Ag, Au): new bimetallic porous coordination polymers with spin-crossover properties.
2013
Two new heterobimetallic porous coordination polymers with the formula [Fe(TPT)2/3{MI(CN)2}2]¿nSolv (TPT=[(2,4,6-tris(4-pyridyl)-1,3,5-triazine]; MI=Ag (nSolv=0, 1¿MeOH, 2¿CH2Cl2), Au (nSolv=0, 2¿CH2Cl2)) have been synthesized and their crystal structures were determined at 120¿K and 293¿K by single-crystal X-ray analysis. These structures crystallized in the trigonal R-3m space group. The FeII ion resides at an inversion centre that defines a [FeN6] coordination core. Four dicyanometallate groups coordinate at the equatorial positions, whilst the axial positions are occupied by the TPT ligand. Each TPT ligand is centred in a ternary axis and bridges three crystallographically equivalent Fe…
Heterotetranuclear Complexes of Reduced and Non-reduced Bridging 1,2,4,5-Tetrazine Ligands with 1,1′-Bis(diphenylphosphanyl)-ferrocene-copper(I)
2015
The complexes {(μ-bptz)[Cu(dppf)]2}(BF4)2 [(1)(BF4)2] [bptz = 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine, dppf = 1,1′-bis(diphenylphosphanyl)ferrocene] and {(μ-bpztz)[Cu(dppf)]2}(PF6)2 [(2)(PF6)2] [bpztz = 3,6-bis(2-pyrazinyl)-1,2,4,5-tetrazine] contain two redox-active heterodinuclear FeIICuI moieties, bridged by a redox-active ligand. A crystal structure determination of (1)(BF4)2·2CH2Cl2 confirms the non-reduced aromatic nature of the bridge, in contrast to previous results on dicopper(I) complexes of bptz. Facile one-electron reduction produces the radical complexes {(μ-bptz)[Cu(dppf)]2}+ (1+) and {(μ-bpztz)[Cu(dppf)]2}+ (2+), which could be isolated [as (1)(BF4)] and studied by variable freq…
Herbizide, VI [1] kernfluorierte 2,4-dianilino-6-(dihexylamino)-1,3,5-triazine
1985
Zusammenfassung Auf dem Wege der nucleophilen Substitution der Chloratome in 2,4-Dichlor- 6-(dihexylamino)-1,3,5-triazin durch Anilin werden das 2,4-Dianilino-6-(dihexylamino)-1,3,5-triazin und durch fluorierte Amine die (Dihexylamino)- 1,3,5-triazine mit den folgenden Resten zuganglich: (2-Fluoranilino)-, (3-Fluoranilino)-, (4-Fluoranilino)-, (2,4-Difluoranilino)-, (2,5-Difluoranilino)- und (2,6-Difluoranilino)-. Zur Charakterisierung der neuen Verbindungen sind die IR-, 1 H-NMR- und Massenspektroskopie herangezogen worden. 2,4-Bis-(2,4-difluoranilino)-6-(dihexylamino)-1,3,5-triazin vermag insbesondere herbizide und antidiabetische Wirkungen auszuuben.