1445-69-8Relevant articles and documents
Phthalazine-1,4-dione derivatives as non-competitive AMPA receptor antagonists: design, synthesis, anticonvulsant evaluation, ADMET profile and molecular docking
El-Helby, Abdel-Ghany A.,Ayyad, Rezk R. A.,El-Adl, Khaled,Elkady, Hazem
, p. 283 - 298 (2019)
In view of the anticonvulsant activity reported for phthalazine derivatives as non-competitive AMPA receptor antagonists, a new series of phthalazine-1,4-diones (2–12) were designed and synthesized. The neurotoxicity was assessed using rotarod test. The molecular docking was performed for the synthesized compounds to assess their binding affinities toward AMPA receptor as non-competitive antagonists. The molecular modeling data were strongly interrelated to biological screening data. Compounds 8, 7b, 7a, 10 and 3a exhibited the highest binding affinities as non-competitive AMPA receptor antagonists and also showed the highest relative potencies of 1.78, 1.66, 1.60, 1.59 and 1.29, respectively, as anticonvulsants in comparison with diazepam. The most active compounds 8, 7b, 7a, 10 and 3a were further tested against maximal electroshock seizure (MES). Compounds 8 and 7b and 3a showed 100% protection at a dose level of 125?μgm/kg, while compounds 7a and 10 exhibited 83.33% protection at the same dose level. These agents exerted low neurotoxicity and high safety margin in comparison with valproate as a reference drug. Most of our designed compounds exhibited good ADMET profile.
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Casadio et al.
, p. 97 (1968)
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Reaction of α-Acetoxy-N-nitrosopyrrolidine with Deoxyguanosine and DNA
Wang, Mingyao,McIntee, Edward J.,Shi, Yongli,Cheng, Guang,Upadhyaya, Pramod,Villalta, Peter W.,Hecht, Stephen S.
, p. 1428 - 1434 (2001)
We investigated the reactions of α-acetoxy-N-nitrosopyrrolidine (α-acetoxyNPYR) with dGuo and DNA. α-AcetoxyNPYR is a stable precursor to the major proximate carcinogen of NPYR, α-hydroxyNPYR (3). Our goal was to develop appropriate conditions for the analysis of DNA adducts of NPYR formed in vivo. Products of the α-acetoxyNPYR-dGuo reactions were analyzed directly by HPLC or after treatment of the reaction mixtures with NaBH3CN. Products of the α-acetoxyNPYR-DNA reactions were released by enzymatic or neutral thermal hydrolysis of the DNA, then analyzed by HPLC. Alternatively, the DNA was treated with NaBH3CN prior to hydrolysis and HPLC analysis. The reactions of α-acetoxyNPYR with dGuo and DNA were complex. We have identified 13 products of the dGuo reaction - 6 of these were characterized in this reaction for the first time. They were four diastereomers of N2-(3-hydroxybutylidene)-dGuo (20,21), 7-(N-nitrosopyrrolidin-2-yl)Gua (2), and 2-(2-hydroxypyrrolidin-1-yl)deoxyinosine (12). Adducts 20 and 21 were identified by comparison to standards produced in the reaction of 3-hydroxybutanal with dGuo. Adduct 2 was identified by its spectral properties while adduct 12 was characterized by comparison to an independently synthesized standard. With the exception of adduct 2, all products of the dGuo reactions were also observed in the DNA reactions. The major product in both the dGuo and DNA reactions was N2-(tetrahydrofuran-2-yl)dGuo (10), consistent with previous studies. Several other previously identified adducts were also observed in this study. HPLC analysis of reaction mixtures treated with NaBH3CN provided improved conditions for adduct identification, which should be useful for in vivo studies of DNA adduct formation by NPYR.
An improved procedure for the preparation of aminomethyl polystyrene resin and its use in solid phase (peptide) synthesis
Harris, Paul W.R.,Yang, Sung Hyun,Brimble, Margaret A.
, p. 6024 - 6026 (2011)
2-Aminoethanol was used to successively replace hydrazine in the preparation of aminomethyl polystyrene resin thereby facilitating purification and by-product removal. The syntheses of the polypeptides ACP (65-74) and oxytocin demonstrated that the use of aminomethyl polystyrene resin prepared in this manner was equal to or better than that prepared using the hydrazine method.
A Peptide Backbone Stapling Strategy Enabled by the Multicomponent Incorporation of Amide N-Substituents
Ricardo, Manuel G.,Marrrero, Javiel F.,Valdés, Oscar,Rivera, Daniel G.,Wessjohann, Ludger A.
, p. 769 - 774 (2019)
The multicomponent backbone N-modification of peptides on solid-phase is presented as a powerful and general method to enable peptide stapling at the backbone instead of the side chains. This work shows that a variety of functionalized N-substituents suitable for backbone stapling can be readily introduced by means of on-resin Ugi multicomponent reactions conducted during solid-phase peptide synthesis. Diverse macrocyclization chemistries were implemented with such backbone N-substituents, including the ring-closing metathesis, lactamization, and thiol alkylation. The backbone N-modification method was also applied to the synthesis of α-helical peptides by linking N-substituents to the peptide N-terminus, thus featuring hydrogen-bond surrogate structures. Overall, the strategy proves useful for peptide backbone macrocyclization approaches that show promise in peptide drug discovery.
Single-particle and ensemble diffusivitiesa-test of ergodicity
Feil, Florian,Naumov, Sergej,Michaelis, Jens,Valiullin, Rustem,Enke, Dirk,Kaerger, Joerg,Braeuchle, Christoph
, p. 1152 - 1155 (2012)
To prove the ergodic theorem experimentally the diffusivities of guest molecules inside a nanostructured porous glass were measured by using two conceptually different approaches under identical conditions. The data obtained through the direct observation of dye-molecule diffusion by single-molecule tracking experiments (red circles) was in perfect agreement with the ensemble value obtained in pulsed-field gradient NMR experiments (black squares). Copyright
Design, synthesis, molecular modeling and biological evaluation of novel 2,3-dihydrophthalazine-1,4-dione derivatives as potential anticonvulsant agents
El-Helby, Abdel Ghany A.,Ayyad, Rezk R.,Sakr, Helmy M.,Abdelrahim, Adel S.,El-Adl,Sherbiny, Farag S.,Eissa, Ibrahim H.,Khalifa, Mohamed M.
, p. 333 - 351 (2017)
In view of their expected anticonvulsant activity, some novel derivatives of 2,3-dihydrophthalazine-1,4-dione 4–22 were designed, synthesized and evaluated using pentylenetetrazole (PTZ) and picrotoxin as convulsion-inducing models. Moreover, the most active compounds were tested against electrical induced convulsion using maximal electroshock (MES) models of seizures. Most of the tested compounds showed considerable anticonvulsant activity in at least one of the anticonvulsant tests. Compounds 13 and 14g were proved to be the most potent compounds of this series with relatively low toxicity in the median lethal dose test when compared with the reference drug. Molecular modeling studies were done to verify the biological activity. The obtained results showed that the most potent compounds could be useful as a template for future design, optimization, and investigation to produce more active analogues.
Effects of mixed H2O-CH3CN solvents on the rate of hydrazinolysis of N-phenylphthalimide: Spectral and kinetic evidence for the occurrence of N-aminophthalimide on the reaction path
Ariffin, Azhar,Leng, Sim Yoke,Lan, Lai Chwee,Khan, M. Niyaz
, p. 147 - 161 (2005)
Kinetic study on the cleavage of N-phenylphthalimide (NPhPT) in the presence of 0.05 M NH2NH2 and mixed H2O-CH 3CN solvents reveals the occurrence of reaction scheme B ← A → C →-An C1↑E → F where A, B, C, C1, An, E, and F represent NPhPT, 0-CO2 -C6H4CONHC6H5, 0-CONHNH2C6H4-CONHC6H5, N-aminophthalimide, aniline, 0-CO2-C6H 4CONHNH2, and 0-CONHNH2C6H 4-CONHNH2, respectively. But, in the presence of either nonbuffered ≥0.20 M NH2NH2 or hydrazine buffer of pH～7.30-8.26 with total buffer concentration ([Buf]T) of > 0.02 M, further conversion of F to 2,3-dihydrophthalazine-1,4-dione (DHPD) has been detected depending upon the length of the reaction time (t), the values of [Buf]T, and pH. It has been shown that the rate of conversion of C1 to F is much faster than that of C to C1 which is much faster than that of F to DHPD. The reaction step A → C involves general base (GB) catalysis, while step C → C1 seems to involve specific base-general acid (GA) and GB-GB catalysis.
Pharmacological evaluation of some new 1-substituted-4-hydroxy-phthalazines
Sivakumar, Ramaiya,Kishore Gnanasam, Sundararaj,Ramachandran, Somasundaram,Thomas Leonard, Joseph
, p. 793 - 801 (2002)
In the present study, a series of 1-substituted-4-hydroxyphthalazines were synthesized and characterized by IR, 1H-NMR and Elemental analysis. The compounds were assayed against seizures induced by maximal electroshock (MES) and pentylenetetrazole (scMet). Neurologic deficit was evaluated by the rotarod test. The decrease in the elevated motor activity by introceptive chemical stimuli (amphetamine antagonistic activity) was studied at the dose level of 25 and 50 mg kg-1 and cardiac activity was also studied. All the compounds exhibited significant anticonvulsant activity. Compounds 4, 12, 13 and 17 were most active of the seriesagainst MES-induced seizures. Compounds 2, 4, 13 and 17 exhibited significant decrease in the elevated motor activity at the dose of 50 mg kg-1. Remarkable sympathetic blocking activity was observed with 3, 5, 6, 7, 9 and 15 only.
Kinetic Evidence for the Occurence of a Stepwise Mechanism in Hydrazinolysis of Phthalimide
Khan, M. Niyaz
, p. 4536 - 4541 (1995)
The apparent second-order rate constants, knapp, for the reaction of hydrazine with phthalimide at a constant pH follow the empirical relationship knapp = A1T/(1 + A2T), where T represents the total hydrazine buffer concentration.The nonlinear variation of knapp against T is attributed to the change in the rate-determining step with change in T at a constant pH, and this provides evidence for the existence of an intermediate on the reaction path.The cyclization of o-(aminocarbamoyl)benzamide to 2,3-dihydrophthalazine-1,4-dione involves N-aminophthalimide as the intermediate.
An improved non-chromatographic scale-up synthesis of a new 1,6,7,8-substituted-4-oxo-1,4-dihydroquinoline-3-carboxylic acid as a potent bacterial topoisomerase inhibitor
Li, Xun,Youells, Scott,Russell, Ronald K.,Roessler, Armin,Schmid, Tobias,Faessler, Roger,Weidner-Wells, Michele A.,Grant, Eugene B.,Macielag, Mark J.
, p. 151 - 160 (2010)
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Artificial Iron Proteins: Modeling the Active Sites in Non-Heme Dioxygenases
Batyuk, Alexander,Bhowmick, Asmit,Borovik, A. S.,Brewster, Aaron S.,Follmer, Alec H.,Fuller, Franklin D.,Green, Michael T.,Gul, Sheraz,Heinisch, Tillmann,Kern, Jan,Kim, In-Sik,Miller, Kelsey R.,Mittra, Kaustuv,Paretsky, Jonathan D.,Sauter, Nicholas K.,Sutherlin, Kyle D.,Ward, Thomas R.,Yano, Junko
, p. 6000 - 6009 (2020)
An important class of non-heme dioxygenases contains a conserved Fe binding site that consists of a 2-His-1-carboxylate facial triad. Results from structural biology show that, in the resting state, these proteins are six-coordinate with aqua ligands occupying the remaining three coordination sites. We have utilized biotin-streptavidin (Sav) technology to design new artificial Fe proteins (ArMs) that have many of the same structural features found within active sites of these non-heme dioxygenases. An Sav variant was isolated that contains the S112E mutation, which installed a carboxylate side chain in the appropriate position to bind to a synthetic FeII complex confined within Sav. Structural studies using X-ray diffraction (XRD) methods revealed a facial triad binding site that is composed of two N donors from the biotinylated ligand and the monodentate coordination of the carboxylate from S112E. Two aqua ligands complete the primary coordination sphere of the FeII center with both involved in hydrogen bond networks within Sav. The corresponding FeIII protein was also prepared and structurally characterized to show a six-coordinate complex with two exogenous acetato ligands. The FeIII protein was further shown to bind an exogenous azido ligand through replacement of one acetato ligand. Spectroscopic studies of the ArMs in solution support the results found by XRD.
Structural identification between phthalazine-1,4-diones and n-aminophthalimides via vilsmeier reaction: Nitrogen cyclization and tautomerization study
Chung, Cheng-Yen,Li, Sin-Min,Lin, Hui-Yi,Tsai, Shuo-En,Tseng, Ching-Chun,Wong, Fung Fuh
supporting information, (2021/05/31)
N-aminophthalimides and phthalazine 1,4-diones were synthesized from isobenzofuran1,3-dione, isoindoline-1,3-dione, furo [3,4-b] pyrazine-5,7-dione, or 1H-pyrrolo [3,4-c] pyridine-1,3dione with monohydrate hydrazine to carry out the 5-exo or 6-endo nitrogen cyclization under the different reaction conditions. Based on the control experimental results, 6-endo thermodynamic hydrohydrazination and kinetical 5-exo cyclization reactions were individually selective formation. Subsequently, Vilsmeier amidination derivatization was successfully developed to probe the structural divergence between N-aminophthalimide 2 and phthalazine 1,4-dione 3. On the other hand, the best tautomerization of N-aminophthalimide to diazinone was also determined under acetic acid mediated solution.
N-Amino-1,8-Naphthalimide is a Regenerated Protecting Group for Selective Synthesis of Mono-N-Substituted Hydrazines and Hydrazides
Manoj Kumar, Mesram,Venkataramana, Parikibanda,Yadagiri Swamy, Parikibanda,Chityala, Yadaiah
supporting information, p. 17713 - 17721 (2021/11/10)
A new route to synthesis of various mono-N-substituted hydrazines and hydrazides by involving in a new C?N bond formation by using N-amino-1,8-naphthalimide as a regenerated precursor was invented. Aniline and phenylhydrazines are reproduced upon reacting these individually with 1,8-naphthalic anhydride followed by hydrazinolysis. The practicality and simplicity of this C?N dihalo alkanes; developed a synthon for bond formation protocol was exemplified to various hydrazines and hydrazides. N-amino-1,8-naphthalimide is suitable synthon for transformation for selective formation of mono-substituted hydrazine and hydrazide derivatives. Those are selective mono-amidation of hydrazine with acid halides; mono-N-substituted hydrazones from aldehydes; synthesis of N-aminoazacycloalkanes from acetohydrazide scaffold and inserted to hydroxy derivatives; distinct synthesis of N,N-dibenzylhydrazines and N-benzylhydrazines from benzyl halides; synthesis of N-amino-amino acids from α-halo esters. Ecofriendly reagent N-amino-1,8-naphthalimide was regenerated with good yields by the hydrazinolysis in all procedures.
