Copper‐Assisted Click Reactions for Activity‐Based Proteomics: Fine‐Tuned Ligands and Refined Conditions Extend the Scope of Application

Copper‐catalysed alkyne–azide 1,3‐dipolar cycloaddition (CuAAC) is the predominantly used bioconjugation method in the field of activity‐based protein profiling (ABPP). Several limitations, however, including conversion efficiency, protein denaturation and buffer compatibility, restrict the scope of established procedures. We introduce an ABPP customised click methodology based on refined CuAAC conditions together with new accelerating copper ligands. A screen of several triazole compounds revealed the cationic quaternary {3‐[4‐({bis[(1‐tert‐butyl‐1H‐1,2,3‐triazol‐4‐yl)methyl]amino}methyl)‐1H‐1,2,3‐triazol‐1‐yl]propyl}trimethylammonium trifluoroacetate (TABTA) to be a superior ligand. TABTA exhibited excellent in vitro conjugation kinetics and optimal ABPP labelling activity while almost exclusively preserving the native protein fold. The application of this CuAAC‐promoting system is amenable to existing protocols with minimal perturbations and is even compatible with previously unusable buffer systems such as Tris ? HCl.     

Design, synthesis, and in vitro antifungal activity of 1-[(4-substituted-benzyl)methylamino]-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazol-1-yl)propan-2-ols

As part of our studies focused on the design of 1‐[((hetero)aryl‐ and piperidinylmethyl)amino]‐2‐phenyl‐3‐(1H‐1,2,4‐triazol‐1‐yl)propan‐2‐ols as antifungal agents, we report the development of new extended benzylamine derivatives substituted at the para position by sulfonamide or retrosulfonamide groups linked to alkyl or aryl chains. These molecules have broad‐spectrum antifungal activities not only against Candida spp., including fluconazole‐resistant strains, but also against a filamentous species (A. fumigatus). Concerning fluconazole resistance, selected compounds exhibit the capacity to overcome CDR and ERG11 gene upregulation and to maintain antifungal activity despite a recognized critical CYP51 substitution in C. albicans isolates. Synthesis, investigation of the mechanism of action by sterol analysis in a C. albicans strain, and structure–activity relationships (SARs) are reported.     

Dinitrophenyl Triazoles – “A Class of Energetic Azoles”: Synthesis,Characterisation, and Performance Evaluation Studies

Energetic azoles have shown great potential as powerful energetic molecules, which find various applications in both military and civilian fields. This work describes the synthesis, characterization and performance evaluation of two energetic triazole derivatives, viz. N‐(2,4‐dinitrophenyl)‐3‐nitro‐1H‐1,2,4‐triazole ( 1a ) and N‐(2,4‐dinitrophenyl)‐3‐azido‐1H‐1,2,4‐triazole ( 1b ). The compounds were synthesized from 3‐nitro‐1,2,4‐triazole and 3‐azido‐1,2,4‐triazole, by a simple synthetic route and structurally characterized using FT‐IR and NMR (¹H, ¹³C) spectroscopy as well as elemental analysis. Thermal analyses on the molecules were performed using simultaneous TG‐DTA. Both compounds ( 1a , 1b ) showed good thermal stability with exothermic decomposition peaks at 348 °C and 217 °C, respectively, on DTA. The energetic and sensitivity properties of both compounds like friction sensitivities and heats of formation are reported. The heats of combustion at constant volume were determined using oxygen bomb calorimetry and the results were used to calculate the standard molar heats of formation (Δ_fH^m). The azido derivative ( 1b ) showed a higher positive heat of formation. The thermo‐chemical properties of the compounds as well as the thermal decomposition products were predicted using the REAL thermodynamic code.     

Studies on polyurethanes and polyurethane–ureas derived from divalent metal salts of mono(hydroxybutyl) hexolate

Divalent metal salts of mono(hydroxybutyl)hexolate [M(HBH)₂), M=Ca²⁺, Mn²⁺or Pb²⁺] were synthesized by the reaction of 1,4‐butanediol, 5,6,7,8,10,10‐hexachloro‐3a,4,4a,5,8,8a,9,9a‐octahydro‐5,8‐methanonaphtho‐[2,3‐C]‐furan‐1,3‐dione and divalent metal acetates. Hexamethylene bis [N′‐(1‐hydroxy‐2‐methyl‐prop‐2‐yl)urea] (HBHMPU) and tolylene 2,4‐bis[N ′‐(1‐hydroxy‐2‐methyl‐prop‐2‐yl)urea] (TBHMPU) were synthesized by reacting 2‐amino‐2‐methyl‐propan‐1‐ol with hexamethylene diisocyanate (HMDI) and tolylene 2,4‐diisocyanate (TDI), respectively, in toluene solvent. Flame‐retardant metal‐containing polyurethanes were synthesized by the solution polymerization of HMDI with M(HBH)₂ and the polyurethane–ureas by reacting HMDI with 1:1 mixture of M(HBH)₂ and HBHMPU or TBHMPU, respectively, in DMSO as solvent. The polymers have been characterized by elemental analysis, solubility, viscosity and IR and ¹H NMR spectroscopy. The thermal stability of the polymers has been studied by thermogravimetry. The flame‐retardant property of the polymers has been investigated by measuring limiting oxygen index values. © 2000 Society of Chemical Industry     

Mono‐, Di‐ and Tetra‐Cationic Surfactants as Carbon Steel Corrosion Inhibitors

Corrosion inhibition of three new synthesized cationic surfactants, N‐(2‐(((Z)‐4‐(pyridin‐4‐yl)but‐3‐en‐1‐yl)amino)ethyl)‐N‐(2‐((E)‐(pyridin‐4‐ylmethylene)amino)ethyl)dodecan‐1‐aminium bromide I(4N), N¹,N²‐didodecyl‐N¹‐((Z)‐4‐(pyridin‐4‐yl)but‐3‐en‐1‐yl)‐N²‐(2‐((E)‐(pyridin‐4‐ylmethylene)amino)ethyl)ethane‐1,2‐diaminium bromide II(4N) and 1‐dodecyl‐4‐((E)‐((2‐(dodecyl(2‐(dodecyl((Z)‐4‐(1‐dodecylpyridin‐1‐ium‐4‐yl)but‐3‐en‐1‐yl)ammonio)ethyl)ammonio)ethyl)imino)methyl)pyridin‐1‐ium bromide IV(4N) on carbon steel was investigated by weight loss, electrochemical impedance spectroscopy and polarization measurements. Results show that the synthesized cationic surfactants inhibit corrosion of carbon steel in 1 M HCl. The inhibitive action occurs by virtue of adsorption on the metal surface following a Langmuir adsorption isotherm model. Polarization curves reveal that the investigated cationic surfactants can be classified as mixed inhibitor types. The variations in the corrosion inhibition efficiency between three cationic surfactants are correlated with their chemical structures, with more hydrophobic surfactants yielding higher inhibition efficiency.     

N-[2-Methyl-5-(triazol-1-yl)phenyl]pyrimidin-2-amine as a scaffold for the synthesis of inhibitors of Bcr-Abl

N‐[2‐Methyl‐5‐(triazol‐1‐yl)phenyl]pyrimidin‐2‐amine derivatives were synthesized and evaluated in vitro for their potential use as inhibitors of Bcr‐Abl. The design is based on the bioisosterism between the 1,2,3‐triazole ring and the amide group. The synthesis involves a copper(I)‐catalyzed azide–alkyne cycloaddition (CuAAC) as the key step, with the exclusive production of anti‐(1,4)‐triazole derivatives. One of the compounds obtained shows general activity similar to that of imatinib; in particular, it was observed to be more effective in decreasing the fundamental function of cdc25A phosphatases in the K‐562 cell line.     

Design,Synthesis, and in vitro Biological Evaluation of 3,5‐Dimethylisoxazole Derivatives as BRD4 Inhibitors

BRD4 has been identified as a potential target for blocking proliferation in a variety of cancer cell lines. In this study, 3,5‐dimethylisoxazole derivatives were designed and synthesized with excellent stability in liver microsomes as potent BRD4 inhibitors, and were evaluated for their BRD4 inhibitory activities in vitro. Gratifyingly, compound 11 h [3‐((1‐(2,4‐difluorophenyl)‐1H‐1,2,3‐triazol‐4‐yl)methyl)‐6‐(3,5‐dimethylisoxazol‐4‐yl)‐4‐phenyl‐3,4‐dihydroquinazolin‐2(1H)‐one] exhibited robust potency for BRD4(1) and BRD4(2) inhibition with IC₅₀ values of 27.0 and 180 nm , respectively. Docking studies were performed to illustrate the strategy of modification and analyze the conformation in detail. Furthermore, compound 11 h was found to potently inhibit cell proliferation in the BRD4‐sensitive cell lines HL‐60 and MV4‐11, with IC₅₀ values of 0.120 and 0.09 μm , respectively. Compound 11 h was further demonstrated to downregulate c‐Myc levels in HL‐60 cells. In summary, these results suggest that compound 11 h is most likely a potential BRD4 inhibitor and is a lead compound for further investigations.     

Polymerization of 4‐(4′‐N‐1,8‐naphthalimidophenyl)‐1,2,4‐triazolidine‐3,5‐dione with diisocyanates

4‐(4′‐Aminophenyl)‐1,2,4‐triazolidine‐3,5‐dione ( 1 ) was reacted with 1,8‐naphthalic anhydride ( 2 ) in a mixture of acetic acid and pyridine (3 : 2) under refluxing temperature and gave 4‐(4′‐N‐1,8‐naphthalimidophenyl)‐1,2,4‐triazolidine‐3,5‐dione ( NIPTD ) ( 3 ) in high yield and purity. The compound NIPTD was reacted with excess n‐propylisocyanate in N,N‐dimethylacetamide solution and gave 1‐(n‐propylamidocarbonyl)‐4‐[4′‐(1,8‐naphthalimidophenyl)]‐1,2,4‐triazolidine‐3,5‐dione ( 4 ) and 1,2‐bis(n‐propylamidocarbonyl)‐4‐[4′‐(1,8‐naphthalimidophenyl)]‐1,2,4‐ triazolidine‐3,5‐dione ( 5 ) as model compounds. Solution polycondensation reactions of monomer 3 with hexamethylene diisocyanate ( HMDI ), isophorone diisocyanate ( IPDI ), and tolylene‐2,4‐diisocyanate ( TDI ) were performed under microwave irradiation and conventional solution polymerization techniques in different solvents and in the presence of different catalysts, which led to the formation of novel aliphatic‐aromatic polyureas. The polycondensation proceeded rapidly, compared with conventional solution polycondensation, and was almost completed within 8 min. These novel polyureas have inherent viscosities in a range of 0.06–0.20 dL g^?1 in conc. H₂SO₄ or DMF at 25°C. Some structural characterization and physical properties of these novel polymers are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2861–2869, 2003     

Microreactor Technology as a Tool for the Synthesis of a Glitazone Drug Intermediate

One of the bottlenecks in the pharmaceutical industry is drug production scale‐up, which can be performed by microreactor technology. Such an approach was applied to the synthesis of (Z)‐5‐(4‐hydroxybenzylidene)thiazolidine‐2,4‐dione, a bioactive aromatic heterocyclic compound belonging to the class of glitazones. n‐Propanol was the best solvent and piperidine the best catalyst for the batch reaction, which was completed in only 5.5 h. In the microreactor, the productivity was almost independent of solvent. The microreactor behaved as a plug‐flow reactor and operated at a steady state for ten hours without efficiency loss. The results suggest that microreactors may replace batch reactors in scaling up drug production.     

Heme Oxygenase Inhibition by 1‐Aryl‐2‐(1H‐imidazol‐1‐yl/1H‐1,2,4‐triazol‐1‐yl)ethanones and Their Derivatives

Previous studies by our research group have been concerned with the design of selective inhibitors of heme oxygenases (HO‐1 and HO‐2). The majority of these were based on a four‐carbon linkage of an azole, usually an imidazole, and an aromatic moiety. In the present study, we designed and synthesized a series of inhibition candidates containing a shorter linkage between these groups, specifically, a series of 1‐aryl‐2‐(1H‐imidazol‐1‐yl/1H‐1,2,4‐triazol‐1‐yl)ethanones and their derivatives. As regards HO‐1 inhibition, the aromatic moieties yielding best results were found to be halogen‐substituted residues such as 3‐bromophenyl, 4‐bromophenyl, and 3,4‐dichlorophenyl, or hydrocarbon residues such as 2‐naphthyl, 4‐biphenyl, 4‐benzylphenyl, and 4‐(2‐phenethyl)phenyl. Among the imidazole‐ketones, five ( 36 – 39 , and 44 ) were found to be very potent (IC₅₀<5 μM ) toward both isozymes. Relative to the imidazole‐ketones, the series of corresponding triazole‐ketones showed four compounds ( 54 , 55 , 61 , and 62 ) having a selectivity index >50 in favor of HO‐1. In the case of the azole‐dioxolanes, two of them ( 80 and 85 ), each possessing a 2‐naphthyl moiety, were found to be particularly potent and selective HO‐1 inhibitors. Three non‐carbonyl analogues ( 87 , 89 , and 91 ) of 1‐(4‐chlorophenyl)‐2‐(1H‐imidazol‐1‐yl)ethanone were found to be good inhibitors of HO‐1. For the first time in our studies, two azole‐based inhibitors ( 37 and 39 ) were found to exhibit a modest selectivity index in favor of HO‐2. The present study has revealed additional candidates based on inhibition of heme oxygenases for potentially useful pharmacological and therapeutic applications.     

Glucocerebrosidase Enhancers for Selected Gaucher Disease Genotypes by Modification of α‐1‐C‐Substituted Imino‐D‐xylitols (DIXs) by Click Chemistry

A series of hybrid analogues was designed by combination of the iminoxylitol scaffold of parent 1C9‐DIX with triazolylalkyl side chains. The resulting compounds were considered potential pharmacological chaperones in Gaucher disease. The DIX analogues reported here were synthesized by CuAAC click chemistry from scaffold 1 (α‐1‐C‐propargyl‐1,5‐dideoxy‐1,5‐imino‐D ‐xylitol) and screened as imiglucerase inhibitors. A set of selected compounds were tested as β‐glucocerebrosidase (GBA1) enhancers in fibroblasts from Gaucher patients bearing different genotypes. A number of these DIX compounds were revealed as potent GBA1 enhancers in genotypes containing the G202R mutation, particularly compound DIX‐28 (α‐1‐C‐[(1‐(3‐trimethylsilyl)propyl)‐1H‐1,2,3‐triazol‐4‐yl)methyl]‐1,5‐dideoxy‐1,5‐imino‐D ‐xylitol), bearing the 3‐trimethylsilylpropyl group as a new surrogate of a long alkyl chain, with approximately threefold activity enhancement at 10 nM . Despite their structural similarities with isofagomine and with our previously reported aminocyclitols, the present DIX compounds behaved as non‐competitive inhibitors, with the exception of the mixed‐type inhibitor DIX‐28.     

Potent,Metabolically Stable 2‐Alkyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐adenines as Adenosine A2A Receptor Ligands

Inhibition of adenosine A_2A receptors has been shown to elicit a therapeutic response in preclinical animal models of Parkinson’s disease (PD). We previously identified the triazolo‐9H‐purine, ST1535, as a potent A_2AR antagonist. Studies revealed that ST1535 is extensively hydroxylated at the ω‐1 position of the butyl side chain. Here, we describe the synthesis and evaluation of derivatives in which the ω‐1 position has been substituted (F, Me, OH) in order to block metabolism. The stability of the compounds was evaluated in human liver microsomes (HLM), and the affinity for A_2AR was determined. Two compounds, (2‐(3,3‐dimethylbutyl)‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐6‐amine ( 3 b ) and 4‐(6‐amino‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐2‐yl)‐2‐methylbutan‐2‐ol ( 3 c ), exhibited good affinity against A_2AR (K_i=0.4 nM and 2 nM , respectively) and high in vitro metabolic stability (89.5 % and 95.3 % recovery, respectively, after incubation with HLM for two hours).     

Microwave‐assisted rapid polycondensation reaction of 4‐(4′‐acetamidophenyl)‐1,2,4‐triazolidine‐3,5‐dione with diisocyanates

4‐(4′‐Aminophenyl)‐1,2,4‐triazolidine‐3,5‐dione was reacted with 1 mol of acetyl chloride in dry N,N‐dimethylacetamide (DMAc) at ?15°C and 4‐(4′‐acetamidophenyl)‐1,2,4‐triazolidine‐3,5‐dione [4‐(4′‐acetanilido)‐1,2,4‐triazolidine‐3,5‐dione] (APTD) was obtained in high yield. The reaction of the APTD monomer with excess n‐isopropylisocyanate was performed at room temperature in DMAc solution. The resulting bis‐urea derivative was obtained in high yield and was finally used as a model for the polymerization reaction. The step‐growth polymerization reactions of monomer APTD with hexamethylene diisocyanate, isophorone diisocyanate, and tolylene‐2,4‐diisocyanate were performed under microwave irradiation and solution polymerization in the presence of pyridine, triethylamine, or dibutyltin dilaurate as a catalyst. Polycondensation proceeded rapidly, compared with conventional solution polycondensation; it was almost completed within 8 min. The resulting novel polyureas had an inherent viscosity in the range of 0.07–0.17 dL/g in dimethylformamide or sulfuric acid at 25°C. These polyureas were characterized by IR, ¹H‐NMR, elemental analysis, and thermogravimetric analysis. The physical properties and structural characterization of these novel polyureas are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2103–2113, 2004     

From Mono‐Triazolium Salt to Bis‐Triazolium Salt: Improvement of the Asymmetric Intermolecular Benzoin Condensation

A solution to the long‐standing challenge of developing a highly effective method for the enantioselective intermolecular benzoin condensation of aromatic aldehydes is described. The chiral bis‐bicyclic triazolium salt – 1,3‐bis{(S)‐5‐benzyl‐6,8‐dihydro‐5H‐[1,4]oxazino[2,1‐c][1,2,4]triazol‐2‐ium‐2‐yl}benzene dichloride [(S)‐ 5a‐1 ] is currently the most efficient precatalyst for the asymmetric variant of the benzoin condensation.     

Design of gem‐Difluoro‐bis‐Tetrahydrofuran as P2 Ligand for HIV‐1 Protease Inhibitors to Improve Brain Penetration: Synthesis,X‐ray Studies,and Biological Evaluation

The structure‐based design, synthesis, biological evaluation, and X‐ray structural studies of fluorine‐containing HIV‐1 protease inhibitors are described. The synthesis of both enantiomers of the gem‐difluoro‐bis‐THF ligands was carried out in a stereoselective manner using a Reformatskii–Claisen reaction as the key step. Optically active ligands were converted into protease inhibitors. Two of these inhibitors, (3R,3aS,6aS)‐4,4‐difluorohexahydrofuro[2,3‐b]furan‐3‐yl(2S,3R)‐3‐hydroxy‐4‐((N‐isobutyl‐4‐methoxyphenyl)sulfonamido)‐1‐phenylbutan‐2‐yl) carbamate ( 3 ) and (3R,3aS,6aS)‐4,4‐difluorohexahydrofuro[2,3‐b]furan‐3‐yl(2S,3R)‐3‐hydroxy‐4‐((N‐isobutyl‐4‐aminophenyl)sulfonamido)phenylbutan‐2‐yl) carbamate ( 4 ), exhibited HIV‐1 protease inhibitory K_i values in the picomolar range. Both 3 and 4 showed very potent antiviral activity, with respective EC₅₀ values of 0.8 and 3.1 nM against the laboratory strain HIV‐1_LAI. The two inhibitors exhibited better lipophilicity profiles than darunavir, and also showed much improved blood–brain barrier permeability in an in vitro model. A high‐resolution X‐ray structure of inhibitor 4 in complex with HIV‐1 protease was determined, revealing that the fluorinated ligand makes extensive interactions with the S2 subsite of HIV‐1 protease, including hydrogen bonding interactions with the protease backbone atoms. Moreover, both fluorine atoms on the bis‐THF ligand formed strong interactions with the flap Gly 48 carbonyl oxygen atom.     

Synthesis and Structure–Activity Relationship Studies of Derivatives of the Dual Aromatase–Sulfatase Inhibitor 4‐{[(4‐Cyanophenyl)(4H‐1,2,4‐triazol‐4‐yl)amino]methyl}phenyl sulfamate

4‐{[(4‐Cyanophenyl)(4H‐1,2,4‐triazol‐4‐yl)amino]methyl}phenyl sulfamate and its ortho‐halogenated (F, Cl, Br) derivatives are first‐generation dual aromatase and sulfatase inhibitors (DASIs). Structure–activity relationship studies were performed on these compounds, and various modifications were made to their structures involving relocation of the halogen atom, introduction of more halogen atoms, replacement of the halogen with another group, replacement of the methylene linker with a difluoromethylene linker, replacement of the para‐cyanophenyl ring with other ring structures, and replacement of the triazolyl group with an imidazolyl group. The most potent in vitro DASI discovered is an imidazole derivative with IC₅₀ values against aromatase and steroid sulfatase in a JEG‐3 cell preparation of 0.2 and 2.5 nM , respectively. The parent phenol of this compound inhibits aromatase with an IC₅₀ value of 0.028 nM in the same assay.     

Fluorescence from fluorescent dye based polyurethane ionomer(III)

A series of reactive fluorescent dyes were successfully synthesized and their structure was proven by IR spectra, NMR spectra, elemental analysis, and mass spectra. The fluorescence performance 6‐amino‐2(‐3‐phenyl‐propyl)‐benzo[de]isoquinoline‐1,3‐dione and 2‐benzyl‐6‐hydroxy‐benzo[de]isoquinoline‐1,3‐dione appears at around 276 and 437.4 nm, respectively, and their quantum yields are 0.662 and 0.562, respectively. It is important to indicate that the fluorescence performance is better for 6‐amino‐2(‐3‐phenyl‐propyl)‐benzo[de]isoquinoline‐1,3‐dione than for as a result of more electron donating groups linked to the 6‐amino‐2(‐3‐phenyl‐propyl)‐benzo[de]isoquinoline‐1,3‐dione molecule. These fluorescent dyes further react with toluene diisocyanate and other additives to form fluorescent dye based polyurethane (PU) ionomer molecules, and their structures are demonstracted by IR spectra. In aqueous solution, the fluorescence performance appears to be better for 6‐amino‐2(‐3‐phenyl‐propyl)‐benzo[de]isoquinoline‐1,3‐dione based PU ionomer than for 6‐amino‐2‐phenyl‐ethyl‐benzo[de]isoquinoline‐1,3‐dione based PU ionomer. For the fluorescent dye based PU ionomer molecule system, the number‐average particle sizes of the fluorescent dye based PU ionomer molecules in water increase with increasing concentration of the fluorescent dye, as a result of the increased free volume of the ionomer molecule. This may be the result of increased intermolecular interactions between ionomer– molecules themselves. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 455–465, 2005     

Synthesis,Biological Activity,and Mechanism of Action of 2‐Pyrazyl and Pyridylhydrazone Derivatives,New Classes of Antileishmanial Agents

In this work, we report the antileishmanial activity of 23 compounds based on 2‐pyrazyl and 2‐pyridylhydrazone derivatives. The compounds were tested against the promastigotes of Leishmania amazonensis and L. braziliensis, murine macrophages, and intracellular L. amazonensis amastigotes. The most potent antileishmanial compound was selected for investigation into its mechanism of action. Among the evaluated compounds, five derivatives [(E)‐3‐((2‐(pyridin‐2‐yl)hydrazono)methyl)benzene‐1,2‐diol ( 2 b ), (E)‐4‐((2‐(pyridin‐2‐yl)hydrazono)methyl)benzene‐1,3‐diol ( 2 c ), (E)‐4‐nitro‐2‐((2‐(pyrazin‐2‐yl)hydrazono)methyl)phenol ( 2 s ), (E)‐2‐(2‐(pyridin‐2‐ylmethylene)hydrazinyl)pyrazine ( 2 u ), and (E)‐2‐(2‐((5‐nitrofuran‐2‐yl)methylene)hydrazinyl)pyrazine ( 2 v )] exhibited significant activity against L. amazonensis amastigote forms, with IC₅₀ values below 20 μm . The majority of the compounds did not show any toxic effect on murine macrophages. Preliminary studies on the mode of action of members of this hydrazine‐derived series indicate that the accumulation of reactive oxygen species (ROS) and disruption of parasite mitochondrial function are important for the pharmacological effect on L. amazonensis promastigotes.     

Non‐Isothermal Kinetic Study of the Thermal Decomposition of Melamine 3‐Nitro‐1,2,4‐triazol‐5‐one Salt

Study on thermal behavior of 3‐nitro‐1,2,4‐triazol‐5‐one (NTO) salts was required to obtain important data for application purposes. These compounds have been shown to be useful intermediates for gun propellant ingredients, high energetic ballistic modifiers for solid propellants and other potential applications. In this paper, thermal decomposition and non‐isothermal kinetics of melamine 3‐nitro‐1,2,4‐triazol‐5‐one salt (MNTO) were studied under non‐isothermal conditions by DSC and TG methods. The kinetic parameters were obtained from analysis of the DSC and TG curves by Kissinger and Ozawa methods. The critical temperature of thermal explosion (T_b) was 574 K. The results show that MNTO is thermally more stable than NTO when compared in terms of the critical temperature of thermal explosion. Finally, the values of ΔS^#, ΔH^#, and ΔG^# of its decomposition reaction were calculated.     

Synthesis and properties of some fluorescent 1,8‐naphthalimide derivatives and their copolymers with methyl methacrylate

Six new fluorescent derivatives of 1,8‐naphthalimide were synthesized. Three were dyes, and three were fluorescent whitening agents (FWAs) containing a tetramethylpiperidine (TMP) stabilizer fragment. The FWAs were obtained under phase‐transfer catalysis conditions. Five of the compounds were copolymerized with methyl methacrylate, so copolymers with an intense color and/or fluorescence stable against solvents were obtained. The chemical bonding of the synthesized monomers in the polymers was confirmed spectrophotometrically. The participation of the monomer compounds did not significantly affect the process of copolymerization or the molecular masses of the obtained copolymers. The quantity of chemically bonded naphthalimide monomer in the copolymers was determined to be over 60%. The spectral properties of the compounds and their photostability in solution and in the copolymers were studied. The influence of the compounds on the photostability of the copolymers was determined. The compounds, especially those containing a stabilizer (TMP) fragment in their molecules, showed a positive stabilizing effect on the photodegradation of poly(methyl methacrylate). Polyamide fabrics with 2‐allyl‐6‐hydrazino‐benzo[de]isoquinoline‐1,3‐dione, 2‐allyl‐6‐(2‐amino‐ethylamino)‐benzo[de]isoquinoline‐1,3‐dione, and 2‐chloro‐N′‐(2‐methyl)‐1,3‐dioxo‐2,3‐dihydro‐1H‐benzo[de] isoquinoline‐6‐yl) acetohydrazide were dyed, and materials with an intense yellow color and fluorescence were obtained. Cotton fabrics were whitened with 2‐(2,2,6,6‐tetramethyl‐piperidin‐4‐yl)‐6‐methoxy‐benzo[de]isoquinoline‐1,3‐dione, 2‐(2,2,6,6‐tetramethyl‐piperidin‐4‐yl)‐6‐allyloxybenzo[de]isoquinoline‐1, 3‐dione, and 2‐[2‐(2,2,6,6‐tetramethyl‐piperidin‐4‐yl)‐1,3‐dioxo‐2,3‐dihidro‐1H benzo [de]isoquinoline‐6‐oxy]ethyl‐2‐methacrylate, and materials with bright whiteness and intense bluish fluorescence were obtained. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009