Synthesis,Structure, and Explosive Properties of a New Trinitrate Derivative of an Unexpected Condensation Product of Nitromethane with Glyoxal

In the condensation reaction of nitromethane with glyoxal carried out in an aqueous solution of sodium hydroxide, 3,6‐dinitro‐cyclohexane‐1,2,4,5‐tetraol was obtained (the expected product, described in the literature) and, unexpectedly, also tricyclic nitro‐triol (6b‐nitrohexahydro‐2H‐1,3,5‐trioxacyclopenta[cd]‐pentalene‐2,4,6‐triol), which has been unknown until now, was obtained as the main product. The structure of the compound was confirmed with ¹H NMR and ¹³C NMR spectroscopy, LR, and HR‐MS techniques and with single‐crystal X‐ray diffractometry. The tricyclic triol (formally a hemiacetal) was transformed into 6b‐nitrohexahydro‐2H‐1,3,5‐trioxacyclopenta[cd]‐pentalene‐2,4,6‐triyl trinitrate by reaction with 98 % HNO₃. Some explosive properties of this compound were determined including: friction and impact sensitivity, activation energy, detonation velocity, heat of combustion in an oxygen atmosphere and enthalpy of formation. The nitrate ester is a powerful explosive with performance close to that of pentaerythritol tetranitrate (PETN).     

Synthesis,characteristics, and phase behavior of a thermosensitive and pH‐sensitive polyelectrolyte

A series of poly(N‐isopropylacrylamide‐co‐methacrylic acid‐co‐octadecyl acrylate) (poly(NIPAM‐co‐MAA‐co‐ODA)) with different monomer molar ratios was synthesized. Critical micelle concentration (CMC) of the polyelectrolyte solution was determined and the CMC increase with methacrylic acid content in the polyelectrolyte. The phase behaviors of the polyelectrolyte solution were studied, and the effects of various factors on the phase transition were discussed. The experimental results indicate that the lower critical solution temperature and the phase transition pH depend on the monomer molar ratio in the polyelectrolyte. Effect of polyelectrolyte concentration on phase transition pH was studied, and results shown that the phase‐transition pH is independent of the polyelectrolyte concentration. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis,extraction, and anti‐bacterial studies of some new bis‐1,2,4‐triazole derivatives part I

A series of new bis triazole Schiff base derivatives (4) were prepared in good yields by treatment of 4‐amino‐3,5‐diphenyl‐4H‐1,2,4‐triazole (3) with bisaldehydes (1). Schiff bases (4) were reduced with NaBH₄ to afford the corresponding bisaminotriazoles (5). All the new compounds were characterized by IR, ¹H NMR and ¹³C NMR spectral data. Their overall extraction (log K_ex) constants for 1 : 1 (M : L) complexes and CHCl₃/H₂O systems were determined at 25 ± 0.1°C to investigate the relationship between structure and selectivity toward various metal cations. The extraction equilibrium constants were estimated using CHCl₃/H₂O membrane transfer with inductively coupled plasma‐atomic emission spectroscopy spectroscopy. The stability sequence of the triazole derivatives in CHCl₃ for the metal cations was exhibited a characteristic preference order of extractability to metal ions [Fe(III) > Cu(II) > Pb(II) > Co(II) > Ni(II) > Mn(II) > Zn(II) > Mg(II) > Ca(II)]. The compounds were tested for anti‐microbial activity applying agar diffusion technique for 11 bacteria. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Coumarin‐based polymer and its silver nanocomposite as advanced antibacterial agents: Synthetic path,kinetics of polymerization,and applications

A novel polymer bearing coumarin pendants of 4‐allyloxy‐2H‐chromen‐2‐one (ACO) was synthesized by atom transfer radical polymerization (ATRP) in toluene at 110°C using 2‐Bromoisobutyryl bromide (BIBB), Cu (I) Br, and 2,2′‐bipyridyl (bpy) as initiator, catalyst, and ligand, respectively. The most appropriate molar concentration ratio of [ACO] : [BIBB] : [Cu (I) Br] : [bpy] was found to be 40 : 1 : 1 : 2 for controlled polymerization. Successful chain extension polymerization of poly (4‐allyloxy‐2H‐chromen‐2‐one) (PACO) confirms the livingness of the process. The activation energy (E_a) (76.26 kJ mol^?1) and enthalpy of activation (ΔH^?) (73.07 kJ mol^?1) were in good agreement to each other proving the feasibility of the reaction and negative value of entropy of activation (ΔS^?) (?320 J mol^?1 K^?1) supported the highly restricted movement of reacting species in transition state during polymerization. Initial polymer decomposition temperature of PACO was found to be 130°C. SEM analysis revealed that polymer surface is not smooth with pointed rod like shapes. The polymer/Ag nanocomposite was synthesized and examined in view of antibacterial effect against Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Proteus mirabilis, and Klebsiella pneumonae. PACO and its Ag nanocomposite (PACON) have been found to be active selectively against bacterial pathogen E. fecalis with minimum inhibitory concentration of 50 and 32 μg mL^?1, respectively. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis, antiproliferative activity, and structure-activity relationships of 3-aryl-1H-quinolin-4-ones

The antiproliferative activities of 36 3-aryl-1H-quinolin-4-ones were determined against two cancer cell lines (Hep G2 and KB) in vitro. The results indicate that most of these compounds show good cytotoxic activity against human cancer cell lines, but no cytotoxicity against a human normal cell line (L02). The positive control compounds genistein and 5-fluorouracil show no selectivity at inhibiting the growth of the above three cell lines. Generally, compounds that bear a halogen atom at the 8 position and a methoxy group at the 3' position exhibited remarkable cytotoxicity toward human cancer cell lines. Electron-withdrawing substituents at the 6 position decrease the antiproliferative activity significantly. We also put forward a pharmacophore model for 3-aryl-4-quinolinones binding with epidermal growth factor receptor protein tyrosine kinases (EGFR PTK). Out of the 36 synthetic compounds, 34 are reported for the first time.     

Solvent Extraction of Indium,Gallium, and Zinc Ions with Acidic Organophosphates having Bulky Alkyl Groups

The extraction equilibria of In³⁺, Ga³, and Zn²⁺ with bis(4‐ethylcyclohexyl)phosphoric acid (D4ECHPA), bis(4‐cyclohexylcyclohexyl)phosphoric acid (D4DCHPA), and bis(2‐ethylhexyl)phosphoric acid (D2EHPA) were investigated in acidic aqueous sulfate media. The order of extractability of metal ions is D4DCHPA > D2EHPA > D4ECHPA, which corresponds to the lipophilicity (log P) of the extractants. The separation factors, β_(In/Ga) and β_(Ga/Zn), of D4ECHPA and D4DCHPA are greater or comparable than that of D2EHPA, because of the steric hindrance of the bulky cyclohexyl groups. In³⁺ can be therefore separated from simulated liquor containing a high concentration of Zn²⁺ by D4DCHPA.     

Synthesis,characterization, and biodegradation of carboxymethylchitosan‐g‐medium chain length polyhydroxyalkanoates

Grafting of medium chain length polyhydroxyalkanoates (mcl‐PHA) produced by Comamonas testosteroni onto carboxymethylchitosan (CMCH) using ceric ammonium nitrate (CAN) as an initiator was carried out under nitrogen atmosphere in aqueous medium. The grafting composition was 2 g CMCH, 0.2M CAN, and 0.5 g mcl‐PHA. The reaction was carried out at 40°C ± 1°C for 4.5 h, and reaction product was extracted by acetone precipitation. The CMCH‐g‐mcl‐PHA copolymers were characterized by Fourier transform infrared spectroscopy, Thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. The data obtained showed successful grafting of mcl‐PHA onto CMCH polymer. TGA results indicated that the graft was stable up to 380°C, and the solubility studies revealed a high % grafting efficiency. Biodegradation studies of the graft in terms of microbial growth, extracellular protein concentration, and % weight loss in the graft were carried out for 30 days using a bacterial isolate Burkholderia cepacia 202 and a fungal isolate Aspergillus fumigatus 202. 93% weight loss of the graft was obtained in case of A. fumigatus 202, whereas B. cepacia 202 showed 76% loss in weight of the graft. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

D-SAP: a new, noncytotoxic, and fully protease resistant cell-penetrating peptide

Protease resistant cell-penetrating peptides (CPPs) are promising carriers for drugs unable to cross the cell membrane. As these CPPs are stable in vivo for much longer periods of time compared to other classes of therapeutic peptides, noncytotoxicity is a property sine qua non for their pharmacological development. Described herein is a fully protease resistant CPP that is noncytotoxic at concentrations up to 1 mM. Proteolytic stability was obtained by chiral inversion of the residues of a known self-assembling CPP-from all L-amino acids to all D-amino acids-and then assessed against trypsin and human serum. Circular dichroism studies confirmed the enantiomeric structure of the analogue, and transmission electron microscopy (TEM) studies indicated that the new inverso analogue retains the ability of the original peptide to self-assemble. The results of uptake experiments indicate that the protease-stable (that is, D-amino acid) analogue of the peptide is internalised by cells to the same extent as the protease-susceptible (that is, L-amino acid) parent peptide. Also reported herein are the results of studies on the cellular internalisation mechanism of the all-D analogue, which reveal the steps followed by the peptide upon its entry into the cell.     

Retention of Eucalyptol,a Natural Volatile Insecticide,in Delivery Systems Based on Hydroxypropyl‐β‐Cyclodextrin and Liposomes

Eucalyptol (Euc) is a natural monoterpene with insecticide effects. Being highly volatile and sensitive to ambient conditions, its encapsulation would enlarge its application. Euc‐loaded conventional liposomes (CL), cyclodextrin/drug inclusion complex, and drug‐in‐cyclodextrin‐in‐liposomes (DCL) are prepared to protect Euc from degradation, reduce its evaporation, and provide its controlled release. The liposomal suspension is freeze‐dried using hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as cryoprotectant. The liposomes are characterized before and after freeze‐drying. The effect of Euc on the fluidity of liposomal membrane is also examined. A release study of Euc from delivery systems, in powder and reconstituted forms, is performed by multiple head extraction at 60 °C after 6 months of storage at 4 °C. CL and DCL suspensions are homogeneous, show nanometric vesicles size, spherical shape, and negative surface charge before and after freeze‐drying. Moreover, HP‐β‐CD does not affect the fluidity of liposomes. CL formulations present a weak encapsulation for Euc. The loading capacity of eucalyptol in DCL is 38 times higher than that in CL formulation. In addition, freeze‐dried DCL and HP‐β‐CD/Euc inclusion complex show a higher retention of eucalyptol than CL delivery system. Both carrier systems HP‐β‐CD/Euc and Euc‐loaded DCL decrease Euc evaporation and improve its retention. Practical Applications: Eucalyptol is a natural insecticide. It is highly volatile and poorly soluble in water. To enlarge its application, its encapsulation in three delivery systems (conventional liposomes, cyclodextrin/drug inclusion complex, combined system composed of cyclodextrin inclusion complex and liposome) is studied. In this paper it is proved that cyclodextrin/eucalyptol inclusion complex and eucalyptol‐in‐cyclodextrin‐in‐liposome are effective delivery systems for encalyptol encapsulation, retention, and release.     

Structural changes of regenerated cellulose dissolved in FeTNa,NaOH/thiourea,and NMMO systems

Regenerated cellulose was prepared from microcrystalline cellulose (MCC) via dissolution in three well‐known nonderivatizing systems: ferric chloride/sodium tartarate/sodium hydroxide (FeTNa), sodium hydroxide/thiourea (NaOH/thiourea), and N‐methylmorpholine‐N‐oxide (NMMO) systems. The effect of regeneration using the different systems on the supramolecular structure of the regenerated celluloses was studied using X‐ray diffraction and Fourier transform infrared (FTIR). The effect of regeneration on supermolecular structure, morphology, and thermal stability of regenerated celluloses were studied using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The effect of regeneration systems used on the chemical reactivity of cellulose toward carboxymethylation, acetylation, and cyanoethylation reactions was briefly studied. The results showed dependence of all the aforementioned properties on the dissolution reagent used in spite of that all studied reagents cause the same change in cellulose crystalline structure (from cellulose I to cellulose II). The degree of polymerization, crystallinity, and thermal stability of the regenerated cellulose (RC) samples were in the following order: NaOH/thiourea RC > FeTNa RC > NMMO RC. SEM micrograph showed unique surface for the NMMO RC sample. The reactivity of the different regenerated cellulose samples toward carboxymethylation, cyanoethylation, and acetylation depended mainly on the reaction system and conditions used rather than on crystallinity of regenerated cellulose. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Determination of the Initiating Capability of Detonators Containing TKX‐50, MAD‐X1, PETNC,DAAF, RDX,HMX or PETN as a Base Charge,by Underwater Explosion Test

A comprehensive investigation to determine the initiation power of detonators containing as a base charge the novel explosives: dihydroxylammonium 5,5′‐bis(tetrazolate‐1N‐oxide) – TKX‐50, dihydroxylammonium 5,5′‐bis(3‐nitro‐1,2,4‐triazolate‐1N‐oxide) – MAD‐X1, pentaerythritol tetranitrocarbamate – PETNC and 3,3′‐diamino‐4,4′‐azoxyfurazan – DAAF in comparison with RDX, HMX and PETN was undertaken. In order to estimate the initiation power of the detonators, the underwater initiating capability test was used. The total energy as a sum of the primary shock wave energy and the bubble gas energy was determined for each of these explosives, by measuring the overpressure of the shock waves generated in water. Moreover, the complete synthesis for novel explosives is presented. The thermal behavior of the explosives was investigated using DSC (differential scanning calorimetry). The gas phase absolute molar enthalpies at 298 K and 10⁵ Pa were calculated theoretically using the modified complete basis set method (CBS‐4M; M referring to the use of minimal population localization) with the Gaussian 09 software. Gas phase standard molar enthalpies of formation (ΔH_f°_(g)) at 298 K were computed using the atomization energy method. Standard molar enthalpies of formation (▵H_(s)°) were calculated using ΔH_f°_(g) and the standard molar enthalpies of sublimation by applying Trouton’s rule. The Chapman‐Jouguet (CJ) characteristics based on calculated ▵H_(s)° values were computed using the EXPLO5 V6.01 thermochemical computer code. For the calculations the theoretical maximum densities and densities obtained during the experiments presented in this work were used.     

An Ab Initio Theoretical Study of 2,4,6‐Trinitro‐1,3,5‐Triazine, 3,6‐Dinitro‐1,2,4,5‐Tetrazine,and 2,5,8‐Trinitro‐Tri‐s‐Triazine

In order to evaluate 2,4,6‐trinitro‐1,3,5‐triazine (TNTAz), 3,6‐dinitro‐1,2,4,5‐tetrazine (DNTAz), and 2,5,8‐trinitro‐tri‐s‐triazine (TNTsTAz), the geometries of these compounds have been fully optimized employing the B3LYP density functional method and the AUG‐cc‐pVDZ basis set. The accurate gas phase enthalpies of formation have been obtained by using the atomization procedure and designing isodesmic reactions in which the parent rings are not destroyed. Based on B3LYP/AUG‐cc‐pVDZ calculated geometries and natural charges, the crystal structures have been predicted using the Karfunkel–Gdanitz method. Computed results show that there exists extended conjugation over the parent rings of these compounds. More energy content is reserved in DNTAz than in both TNTAz and TNTsTAz. The title compounds are much more sensitive than 1,3,5‐trinitrobenzene. The calculated detonation velocity of DNTAz reaches 9.73–9.88 km s⁻¹, being larger than those of CL‐20 and TNTAz. TNTsTAz has no advantage over the widely used energetic compounds such as RDX and HMX.     

Aliphatic–aromatic polyester–polyaniline composites: preparation,characterization, antibacterial activity and conducting properties

Poly(butylene adipate‐co‐terephthalate) (PBAT) composites containing polyaniline (PANI) were prepared using a melt blending process. Acrylic‐acid‐grafted PBAT (PBAT‐g‐AA) and PANI were used to improve the compatibility and dispersibility of PANI within the PBAT matrix. The composites were characterised morphologically using scanning electron microscopy, chemically using Fourier transform IR spectrometry and ¹³C solid‐state nuclear magnetic resonance, and optically using UV‐visible spectroscopy. The electrical conductivity of the composites was also evaluated with a resistance tester and a cyclic voltameter. Escherichia coli (BCRC 10239) was chosen as the standard bacterium for determining the antibacterial properties of the composite materials. The anti‐static properties of the composites were also evaluated. The PBAT‐g‐AA/PANI composite showed markedly enhanced antibacterial and anti‐static properties due to the formation of amide bonds by the condensation of the carboxylic acid groups of PBAT‐g‐AA with the amino groups of PANI. The optimal level of PANI was 9 wt%, as excess PANI led to separation of the two organic phases, lowering their compatibility. Copyright © 2012 Society of Chemical Industry     

Well‐defined polymers containing 1,3‐dichloro‐tetra‐n‐butyl‐distannoxane moiety: Synthesis,mechanism, and applications in catalysis

A series of well‐defined different chain lengths polymers, which contain the organometallic 1,3‐dichloro‐tetra‐n‐butyl‐distannoxane core in the main chain, was obtained in one‐pot via a novel 1,3‐dichloro‐tetra‐n‐butyl‐distannoxane (complex A )/azobisisobutyronitrile (AIBN) initiating system used in reverse atom transfer radical polymerization of styrene in different concentrations. The introduction of organotin complex A was supported by ¹H‐NMR, ¹³C–NMR, and the Inductive Coupled Plasma Emission Spectrometer analysis of the organotin‐containing polymer. Moreover, the mechanism of polymerization was investigated by changing the ratio of complex A to AIBN. It was concluded that the complex A not only acted as an important part of the initiator system but also introduced the functional organometallic group into the polymer chain. Additionally, the organotin‐containing polymer could be used as catalyst for esterification, and the reaction products' conversion could reach high up to 99% and does not decrease after four successive cycles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

3-Chloro-2-hydroxypropyl Dimethyl Dehydroabietyl Ammonium Chloride: Synthesis,Characterization, and Physicochemical Properties

3‐Chloro‐2‐hydroxypropyl dimethyl dehydroabietyl ammonium chloride (CHPDMDHA) was synthesized from dehydroabietylamine (DHA) and epichlorodrin. The synthesis was done in three steps. First, DHA was transformed into N,N‐dimethyl dehydroabietyl amine (DMDHA) through Eschweiler‐Clarke Reaction. Second, the DMDHA was reacted with hydrochloric acid and translated into DMDHA hydrochloride. Third, the CHPDMDHA was obtained after the DMDHA hydrochloride had reacted with epichlorodrin and recrystallized using a solvent composed of ethyl acetate and ethanol. The critical micelle concentrations (CMC) of CHPDMDHA at 25 °C was found to be 2.56 × 10^?4 mol L^?1, and its surface tension at the CMC (γ_CMC) was determined to be 27.4 mN m^?1; these data suggest that the surface activities of CHPDMDHA are better than those of benzalkonium chloride (BC), so that CHPDMDHA could be used as a good alternative to BC.     

Oxidative Aminocarbonylation of Terminal Alkynes for the Synthesis of Alk‐2‐ynamides by Using Palladium‐on‐Carbon as Efficient,Heterogeneous, Phosphine‐Free,and Reusable Catalyst

Palladium‐on‐carbon (Pd/C)‐catalyzed oxidative aminocarbonylations of alk‐1‐ynes with secondary amines provide the corresponding alk‐2‐ynamides in a good to excellent yields. This new methodology is applicable for the synthesis of a wide range of biologically active alk‐2‐ynamide derivatives. The developed protocol avoids the use of phosphine ligands, with an additional advantage of palladium catalyst recovery and reuse for up to four consecutive cycles.     

Alpha‐Linolenic Acid,but Not Palmitic Acid,Negatively Impacts Survival,Asexual Reproductive Rate,and Clonal Offspring Size in Hydra oligactis

Hydra, as sit‐and‐wait predators with limited food selectivity, could serve as model organisms for the analysis of the effect of a particular dietary component on growth and reproduction. We investigated the effect of food quality and of diets enriched with palmitic (PAM) or α‐linolenic acid (ALA) on the life history traits of two hydra species: Hydra oligactis and Hydra vulgaris. We tested the hypothesis that a diet enriched with polyunsaturated fatty acids (PUFA) can stimulate growth and reproduction in simple metazoans with a sit‐and‐wait type of predatory strategy. Our results revealed that a diet based on Artemia nauplii, which are not a natural food for freshwater hydra, stimulated growth, asexual reproduction, and survival in hydra. Artemia nauplii were characterized by the highest lipid content of all used food sources. The analysis of the fatty acid content of hydra indicated the domination the n‐6 fatty acids over n‐3 (eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA], and ALA). Arachidonic acid appeared to be the dominant PUFA in Hydra, irrespective of diet supplementation with palmitic acid or ALA. The dietary supplementation of ALA negatively affected the survival, asexual reproductive rate, and size of clonal offspring of H. oligactis and had no effect on the life history traits of H. vulgaris. Our results also suggest that the hydras are not able to efficiently convert ALA into other essential fatty acids, such as EPA and DHA. To our knowledge, this is the first report about the adverse effects of n‐3 fatty acid supplementation in primitive metazoans such as hydra.