Isopropylamine Research Articles

Toxicity of Cúspide 480SL® spray mixture formulation of glyphosate to aquatic organisms.

In 2011, an alternative formulation of glyphosate (Cúspide 480SL®) was chosen to replace Roundup-SL®, Fuete-SL®, and Gly-41® for the control of Erythroxylum coca, the source of cocaine, in Colombia. Cúspide 480SL contains the active ingredient glyphosate isopropylamine (IPA) salt, which is the same active ingredient used in previous formulations. However, Cúspide 480SL contains an alkyl polyglycoside surfactant rather than the polyethoxylated tallow amine (POEA) surfactant used in other formulations and known to be more toxic to nonprimary producing aquatic organisms than glyphosate itself. An adjuvant, Cosmo-Flux F411, and water also are added to the spray mixture before application. Aquatic ecosystems adjacent to the target coca fields might be exposed to the spray mix, placing aquatic organisms at risk. Because no toxicity data were available for spray mixture on aquatic organisms, acute toxicity tests were conducted on aquatic plants, invertebrates, and fish, by using the Cúspide 480SL spray mix as described on the label. Based on the median effective concentration (EC50) values for similar organisms, the spray mixture was less toxic to aquatic organisms than formulations previously used for the control of coca (i.e., Roundup-SL, Fuete-SL, and Gly-41). A physical effect induced by Cosmo-Flux F411 was observed in Daphnia magna, Ceriodaphnia dubia, and Hyalella azteca, causing the invertebrates to be trapped in an oily film that was present at the surface of the water. However, a hazard assessment for the Cúspide 480SL spray mix, using estimated worst-case exposure scenario concentrations and EC50 values from the toxicity tests, indicated de minimis hazard for the tested aquatic animals, with hazard quotients all <<1.

Continuous Monoisopropyl Amine Manufacturing: Sustainable Process Design and Plantwide Control

Conceptual design, steady state economic optimization, and decentralized plantwide control of a conventional “reaction followed by separation” process for continuous manufacture of monoisopropyl amine (MIPA) via the catalytic amination of isopropyl alcohol (IPA) is studied. A unique feature of the design is the recycle to extinction of the diisopropyl amine (DIPA) side product for a sustainable zero DIPA discharge process. The reactor effluent mixture separation is complicated by the presence of DIPA–water, IPA–water, and IPA–DIPA minimum boiling binary azeotropes. Using the residue curve map tool, two alternative designs, without a decanter (FS1) and with a decanter (FS2), are devised and optimized with respect to the dominant design variables. A high single-pass reactor conversion is necessary so that the reactor effluent composition is in the appropriate distillation region to guarantee feasibility of the separation scheme. Also, reactor oversizing is needed to ensure operability for a moderately large...

Development of a mitochondria-targeted Hsp90 inhibitor based on the crystal structures of human TRAP1.

The mitochondrial pool of Hsp90 and its mitochondrial paralogue, TRAP1, suppresses cell death and reprograms energy metabolism in cancer cells; therefore, Hsp90 and TRAP1 have been suggested as target proteins for anticancer drug development. Here, we report that the actual target protein in cancer cell mitochondria is TRAP1, and current Hsp90 inhibitors cannot effectively inactivate TRAP1 because of their insufficient accumulation in the mitochondria. To develop mitochondrial TRAP1 inhibitors, we determined the crystal structures of human TRAP1 complexed with Hsp90 inhibitors. The isopropyl amine of the Hsp90 inhibitor PU-H71 was replaced with the mitochondria-targeting moiety triphenylphosphonium to produce SMTIN-P01. SMTIN-P01 showed a different mode of action from the nontargeted PU-H71, as well as much improved cytotoxicity to cancer cells. In addition, we determined the structure of a TRAP1-adenylyl-imidodiphosphate (AMP-PNP) complex. On the basis of comparative analysis of TRAP1 structures, we propose a molecular mechanism of ATP hydrolysis that is crucial for chaperone function.

The effect of non-ionic surfactant in the microwave-assisted synthesis of MTT zeolite optimized by Taguchi method

Here, we report the combination of microwave-assisted synthesis with surfactant as a growth modifier optimized by an orthogonal design method. The effect of a nonionic surfactant, polyoxyethylene 20 stearyl ether (Brij 78) was investigated in the synthesis of MTT zeolite under microwave irradiation. Incorporation of Brij 78 surfactant into a synthesis mixture of SiO2–Al2O3–NaOH–Brij 78–isopropyl amine–H2O was performed at different Brij 78/SiO2 ratio (0.00, 0.04 and 0.07) with different sample precursor aging time in the range of 5 to 48 h. The Taguchi method and the Pareto Analysis of variance were used to elaborate the effects of Brij 78/SiO2 ratio and aging time in (i) minimizing samples mean crystal length (MCL) and (ii) maximizing BET surface areas. Aging time was the most significant parameter in minimizing the MCL of samples, while Brij 78/SiO2 ratio played a significant role in improving specific surface area.

Synthesis of (R)- or (S)-valinol using ω-transaminases in aqueous and organic media

Valinol is part of numerous pharmaceuticals and has various other important applications. Optically pure valinol (ee >99%) was prepared employing different ω-transaminases from the corresponding prochiral hydroxy ketone. By the choice of the enzyme the (R)- as well as the (S)-enantiomer were accessible. Reductive amination was performed in organic solvent (MTBE) using 2-propyl amine as amine donor whereas alanine was applied in or in aqueous medium. Transformations in phosphate buffer were successfully performed even at 200mM substrate concentration (20.4g/L) leading to 99% (R) and 94% (S) conversion with perfect optical purity (>99% ee).

Immobilization of (R)- and (S)-amine transaminases on chitosan support and their application for amine synthesis using isopropylamine as donor

Transaminases from Aspergillus fumigatus ((R)-selective, AspFum), Ruegeria pomeroyi ((S)-selective, 3HMU) and Rhodobacter sphaeroides 2.4.1 ((S)-selective, 3I5T) were immobilized on chitosan with specific activities of 99, 157, and 163U/g and acceptable yields (54, 21, and 23%, respectively) for glutaraldehyde (GA) immobilization. Besides GA, also divinylsulfone was used as linker molecule leading to a similar efficient immobilization for two enzymes, GibZea and NeoFis, whereas GA was superior in the other cases. Storage of the GA-immobilized enzymes for one month resulted in increased relative activities between 120 and 180%. The thermal stability was improved, especially for the GA-immobilized AspFum compared to the free enzyme after incubation for 4h at 60°C (10% vs. 235% residual activity). Especially after incubation of AspFum (free or immobilized) for 2h at 50°C a strongly increased activity was observed (up to 359% of the initial activity). This effect was studied in more detail, revealing that one heat activation prior and one after immobilization increased the overall immobilization efficiency. Recycling of the immobilized ATAs resulted only in a small reduction of activity after four batches. Asymmetric synthesis of (R)- or (S)-1-methyl-3-phenylpropylamine from the prostereogenic ketone using isopropylamine (IPA) as amino donor was applied with conversions up to 50% (AspFum) or 75% (3HMU). Except for NeoFis, all immobilized ATAs showed higher conversions compared to the free enzyme.

Determination of Primary Amine Content in Bonding Agent Used in Composite Solid Propellants

AbstractThe primary amine content in tetraethylenepentamine (TEPA) and TEPAN, a bonding agent used in composite solid propellants, was determined by near infrared (NIR) spectroscopy and the results were compared to those obtained by potentiometry. The band at 4930 cm−1, which showed to be influenced only by primary amine groups, was chosen as the analytical band. The calibration curves based on isopropylamine (IPA) and isopropylamine/dibutylamine (IPA/DBA) mixtures proved to be suitable for determining the NH2 content of TEPA or of samples containing mixtures of NH and NH2 groups. It was found that TEPA contains 26.4 % of NH2 and 25.7 % of NH, and that TEPAN contains 0.5 % of NH2, confirming the low content of primary amine of this bonding agent. The lowest amine equivalent of TEPA is 31.1±0.3 g/eq, as determined by potentiometry, was found because this technique measures the total hydrogen content, including primary and secondary amines. The literature value of 62.6 g/eq for TEPA ACROS obtained by potentiometry in a non aqueous medium and related to the first inflection of the primary amine, validates the value obtained by NIR in this work for a similar type of amine. The equivalent weight obtained by NIR spectroscopy (62.7 g/eq) allowed to calculate the molar mass of TEPA of 195.6 g mol−1, which is close to the typical value of 200 g mol−1.

Hierarchical N‐Doped TiO 2 Microspheres with Exposed (001) Facets for Enhanced Visible Light Catalysis

Hierarchical N-doped TiO2 microspheres with exposed (001) facets [N-TiO2-(001)] were synthesized through a simple, fluorine-free solvothermal reaction with subsequent thermal treatment. The results show that the hierarchical N-TiO2-(001) microspheres are made up of numerous TiO2 nanosheets, and that isopropylamine (IPAN) acts as both the nitrogen source and the capping and shape-controlling agent that generates the high-energy (001) facets. In addition, IPAN is also effective in increasing the onset temperature of the phase transformation of TiO2 from anatase to rutile. Compared with the commercially available P25 TiO2, the as-prepared TiO2 microspheres exhibit good photocatalytic activity and high stability under visible-light irradiation. The high photocatalytic performance is derived from the synergy effect of N-doping and the separation of photogenerated electrons and holes among different facets, as evidenced by surface photovoltage spectroscopy.

Plantwide Control Design of the Monoisopropylamine Process

Plantwide regulatory control system design for a monoisopropylamine (MIPA) process is presented from the perspective of plantwide transient variability propagation. The process consists of a hot reaction section followed by a cold separation section with three columns and a decanter with two liquid recycles. Two control structures with the throughput manipulator (TPM) at, respectively, the limiting reactant fresh feed (CS1) and the decanter feed (CS2) are evaluated. The decanter level control scheme dramatically affects the overall plantwide response speed. The response is extremely sluggish when total decanter hold-up is regulated using the organic outflow (Scheme 1) and is significantly speeded-up (> 3 times) when the total (organic + aqueous) outflow (Scheme 2) is manipulated instead. The reason is traced to Scheme 2 effectively propagating water imbalance transients out of the plant to the water by-product stream and not to the organic recycle stream, which disturbs the side-product recycle-to-extinction balance. The case-study affirms the heuristic of structuring the plantwide control system to propagate transients out of a recycle loop for improved dynamic performance.

폴리아크릴로니트릴의 가수분해와 아미드화에 의한 열감응성 폴리(N-이소프로필아크릴아미드)의 합성과 특성분석

A two-step method for obtaining poly(N-isopropylacrylamide) (PNIPAAm) from poly(acrylonitrile) (PAN) was investigated in order to find a feasibility of imparting thermo-responsive property onto textile fiber materials. PAN was converted to poly(acrylic acid) (PAA) by hydrolysis at a first-step, and then PAA was converted to PNIPAAm at a second step via an amidation reaction of PAA with isopropylamine (IPA) in DMF medium using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) as catalysts. High content of carboxylic groups at the first step was obtained by the successive alkaline and acid hydrolysis of PAN. The degree of conversion of PAA to PNIPAAm at the second step was dependent on the amount of catalysts EDC and NHS. PNIPAAm converted from PAA through amidation reaction showed a lower critical solution temperature (LCST) behavior when the conversion was higher than about 53%.

Synthesis and Characterization of Perfluoro Quaternary Ammonium Ion Exchange Membranes for Fuel Cell Applications

In this work alkaline exchange membranes were prepared from the 3M perfluorinated ionomer by functionalization with two amine species that were further alkylated to quaternary ammonium cations. The methyl amine polymer was successfully quaternized to produce an ion exchange capacity (IEC) of 0.72 meq g-1, while the isopropyl amine did not quaternize resulting a negligible IEC of 0.02 meq g-1. Membrane swelling under a range of humidity conditions was characterized before and after thermal annealing through small angle x-ray scattering. Swelling in the methyl cationic membrane was isolated to the ionic domain and showed little change by thermal annealing. The as-cast aminated isopropyl membranes exhibited inconsistent morphological ordering and hysteresis during humidity cycling. Thermal annealing of the isopropyl amine membrane induced structural reorganization that resisted change during humidity cycling. This work highlights the importance of morphology and thermal conditioning of ion exchange membranes to produce consistent long-term performance.

Comparison of supercritical fluid chromatography and reverse phase liquid chromatography for the impurity profiling of the antiretroviral drugs lamivudine/BMS-986001/efavirenz in a combination tablet

Dual and triple combinations of antiretroviral drugs are a cornerstone of human immunodeficiency virus type 1 (HIV-1) treatment. Supercritical fluid chromatography (SFC) and reverse phase liquid chromatography (RPLC) methods have been developed for the impurity profiling of a prototype combination tablet containing three such drugs: lamivudine, BMS-986001 and efavirenz. Separation by SFC was achieved using a Princeton 2-ethyl pyridine stationary phase and a mobile phase B consisting of methanol with 10mM ammonium acetate and 0.1% isopropyl amine. This combination of mobile phase additives was required for both the separation of minor components and to minimize peak tailing of the active pharmaceutical ingredients (APIs). Separation by RPLC was achieved using a Discovery HSF5 stationary phase and a mobile phase consisting of 10mM ammonium acetate, pH 5.5 and methanol. Mobile phase gradient elution was employed in each case to elute components with a wide range of polarities. Both these methods were found to have advantages and disadvantages. Out of the three APIs and 13 possible impurity/degradation products selected, all were resolved by RPLC. By SFC, 15 peaks were resolved with one co-eluting pair and a high degree of orthogonality was achieved relative to RPLC. A more even distribution of peaks across the separation space, a non-sloping baseline and fewer system peaks were significant advantages associated with the SFC method. Particular attention had to be paid to optimizing the reverse phase diluent strength/initial mobile phase composition to avoid distortion of the peak shapes for early eluting components. This was not an issue with SFC, as the diluent of choice (methanol) was also the solvent of choice (in combination with ≤20% water) for the dissolution of the triple combination tablet. As with RPLC, SFC was found to exhibit the required sensitivity for successful quantitation of potential impurities/degradation products at the 0.05–0.1 area% level.

Synthesis and Surface Activity of N-(2-Hydroxylpropyl) Perfluorooctane Amide Foaming Agent

Non-ionic fluorocarbon surfactant N-(2-hydroxypropyl) perfluorooctane amide was synthesized via the fattyacid method using perfluorooctanoic acid and isopropyl amine as precursors.The structures of products were characterized by infrared adsorption spectra(IR) and nuclear magnetic resonance spectroscopy(NMR).The bubbling potential,foam stability,salt resistance and surface tension of the samples were evaluated and compared with sodium dodecylsulfate(SDS).The results show that foam comprehensive exponent of the product is 1.6 times that of SDS.The foaminess is not obviously influenced by the concentration of inorganic ions.The surface tensions of the samples can be increased up to 9.275 mN/m.At lower concentration,the capability of reducing surface tension is better than that of SDS.The property of the products is strongly influenced by the type and quantity of hydrogen bonds,and the content of amides in the chain of the products.

O2-functionalized methylamine diazeniumdiolates: evidence for E ⇄ Z equilibration in an acyclic system.

Diazeniumdiolates that have the structure RHN-N(O)═NOR' are of interest as prodrug (caged) forms of the bioeffectors nitric oxide (NO) and nitroxyl (HNO). Previous work has focused on examples possessing α-branched R groups, with isopropylamine (IPA)/NO (R = isopropyl) being the smallest examined to date. To probe the effect of minimizing the alkyl-group size on the chemistry of IPA/NO, we prepared the corresponding methylamine derivative as a sodium salt that was highly unstable but could be trapped in very low overall yield as the stable O(2)-benzyl derivative. To prepare enough for efficient characterization, we devised an alternate synthesis involving a novel N-dealkylation route. CH(3)HN-N(O)═NOBn, synthesized in high yield and crystallized as the Z isomer as determined by X-ray crystallography, was observed to exist as a 11:1 mixture of two isomeric forms in dynamic equilibrium in solution. Similar results were seen for the O(2)-ethyl derivative, whose two equilibrium constituents were partially separated by HPLC to reveal essentially identical UV and mass spectra, indicating them to be Z and E isomers of CH(3)HN-N(O)═NOEt. The results could lead the way to a fuller understanding of the chemistry of the acyclic (E)-diazeniumdiolates.

Structural Transformation of Isopropylamine Semiclathrate Hydrates in the Presence of Methane as a Coguest

Guest-induced structural transformation in amine semiclathrate hydrates is a unique pattern caused by modifying the hydrophobic-hydrophilic balance, and thus, it can be applied to potential gas storage and transportation areas. The experimental results of the structural transformation of isopropylamine (IPA) semiclathrate hydrates in the presence of methane (CH(4)) as a coguest are presented with a focus on the macroscopic phase behavior and microscopic analytical methods such as powder X-ray diffraction (PXRD) and NMR spectroscopy. The introduction of CH(4) molecules as coguests changed the structure of the IPA·8.0H(2)O semiclathrate hydrates (hexagonal, P6(3)/mmc) to sII gas hydrates (cubic, Fd3m). The microscopic analysis results indicate that the guest gas distribution and the clathrate hydrate composition can be altered with adjustment of the IPA concentration. The overall experimental results are valuable for increased understanding of the stability conditions, structural details, and guest-host interactions in hydrophobic guest gas + IPA clathrate hydrates.

Experimental Study of Improving the CO&lt;sub&gt;2&lt;/sub&gt; Flooding Development Effect in Ultra-Low Permeability Reservoir

In order to improve the development effect of Chang-6 Oil Reservoir, five sets of different production pressure (1MPa, 2MPa, 3MPa, 4MPa, 5MPa) was designed to do CO2 immiscible flooding experiment to analyze the channeling laws. The experimental results showed that gas breakthrough time and gas channeling time were all shortened with the increasing of the pressure difference, but the ultimate recovery had a fluctuation change, increasing first and decreasing afterwards. And the production sharply increased in the gas breakthrough before and after. The best displacement effect was in 3MPa differential pressure. Then plugging experiment was made under the condition of 3MPa differential pressure, isopropyl amine was as plugging channeling agent. The experimental results: the residual resistance coefficient of plugging channeling agent was 8.56, and the range of enhancing recovery efficiency was 15%.

Green nanoemulsion‐laden glyphosate isopropylamine formulation in suppressing creeping foxglove (A. gangetica), slender button weed (D. ocimifolia) and buffalo grass (P. conjugatum)

Pesticides are developed with carriers to improve their physicochemical properties and, accordingly, the bioefficacy of the applied formulation. For foliar-applied herbicide, generally less than 0.1% of the active ingredient reaching the target site could reduce pesticide performance. Recently, a carrier of nanoemulsion consisting of oil, surfactant and water, with a particle size of less than 200 nm, has been shown to enhance drug permeability for skin penetration in pharmaceutical delivery systems. In the present work, the aim was to formulate a water-soluble herbicide, glyphosate isopropylamine (IPA), using a green nanoemulsion system for a biological activity study against the weeds creeping foxglove, slender button weed and buffalo grass. The nanoemulsion formulations displayed a significantly lower spray deposition on creeping foxglove (2.9-3.5 ng cm(-2) ), slender button weed (2.6-2.9 ng cm(-2) ) and buffalo grass (1.8-2.4 ng cm(-2) ) than Roundup(®) (3.7-5.1 ng cm(-2) ). The visible injury rates of weeds treated with the nanoemulsion formulations were statistically equivalent to those relating to Roundup(®) at 14 days after treatment, with a control range of 86.67-96.67%. It was hypothesised that the significant difference in spray deposition with equal injury rates can be attributed to enhanced bioactivity of the nanoemulsion formulations. This initial discovery could be the platform for developing better penetration of agrochemical formulations in the future.

Immobilization of Escherichia coli containing ω‐transaminase activity in LentiKats®

Whole Escherichia coli cells overexpressing ω-transaminase (ω-TA) and immobilized cells entrapped in LentiKats® were used as biocatalysts in the asymmetric synthesis of the aromatic chiral amines 1-phenylethylamine (PEA) and 3-amino-1-phenylbutane (APB). Whole cells were permeabilized with different concentrations of cetrimonium bromide (CTAB) and ethanol; the best results were obtained with CTAB 0.1% which resulted in an increase in reaction rate by 40% compared to the whole cells. The synthesis of PEA was carried out using isopropyl amine (IPA) and L-alanine (Ala) as amino donors. Using whole cell biocatalysis, the reaction with IPA was one order of magnitude faster than with Ala. No reaction was detected when permeabilized E. coli cells containing ω-TA were employed using Ala as the amino donor. Additionally, the synthesis of APB from 4-phenyl-2-butanone and IPA was studied. Whole and permeabilized cells containing ω-TA and their immobilized LentiKats® counterparts showed similar initial reactions rates and yields in the reaction systems, indicating 100% of immobilization efficiency (observed activity/activity immobilized) and absence of diffusional limitations (due to the immobilization). Immobilization of whole and permeabilized cells containing ω-TA in LentiKats® allowed improved stability as the biocatalyst was shown to be efficiently reused for five reaction cycles, retaining around 80% of original activity.

Screening strategies for achiral supercritical fluid chromatography employing hydrophilic interaction liquid chromatography-like parameters

A thorough evaluation of 5μm bare silica from two major vendors for achiral supercritical fluid chromatography of polar analytes has been carried out. Columns were the same dimension, and a virgin column was reserved for each modifier-mixture combination. Three mixtures were prepared and chromatographically separated via a gradient of methanol-modified CO2 that incorporated 5% (w/w) water as a neutral additive. Mixture (A) invoked both trifluoroacetic acid and water as additives. Mixture (B) utilized isopropyl amine and water; while mixture (C) employed either ammonium acetate and water as additives or only water. Regardless of the mixture components and mobile phase composition, duplicate separations with superior selectivity and excellent peak resolution were observed on five analysis days over a 15-day period. Subsequent removal of water (i.e. primary additive) from each of the mobile phases led to lower selectivity for early eluting components but excellent peak resolution prevailed for later eluting peaks during a later 5-day testing period with only the secondary additive. The re-introduction of 5% water into the mobile phase (after allowing the bare silica columns that were used with no water to sit for 30days) slowly yielded the original separation after approximately five injections. A hydrophilic interaction liquid chromatography (HILIC)-like mechanism for SFC whereby analyte partitions between water absorbed on the silica and water in the mobile phase is proposed. The general utility of this experimental approach with bare silica was subsequently demonstrated by single injection of ten drug-like compounds with each of the four mobile phases that previously were utilized with the three model compound mixtures. In each case, sharp peaks were observed for each drug-like compound regardless of the additive although retention times varied with the additive employed.

Physicochemical characterization and formation of glyphosate-laden nano-emulsion for herbicide formulation

A nano-emulsion system was developed for pesticide formulation. Pseudoternary phase diagrams were constructed consisting emulsion system of long-chain fatty acid methyl esters (LFAMEs)/mixed surfactant/water and a quarternary component, glyphosate isopropylamine (IPA) as a herbicide active. Isotropic (L) regions were formed in the phase diagrams using mixed surfactant long-chain alkylpolyglucosides (LAPG) and ethoxylated 3-(3-hydroxypropyl)-heptamethyltrisiloxane (organosilicone) at the ratios of 9:1, 8:2 and 7:3. Pre-formulation concentrates were chosen from the L regions with less than 20% (w/w) of inerts (LFAMEs+mixed surfactant) and were characterized with regard to particle size, particle aging rate and thermostability study. A pre-formulation concentrate with the lowest aging rate and stable at high temperature (54°C) was selected for the mechanisms study of the pre-formulation concentrate in conjunction with the development of nano-emulsion formulation. The transmission electron microscopy (TEM) result showed that the pre-formulation concentrate appeared as a polymerized multi-connected network. Upon water dilution of the pre-formulation concentrate with gentle stirring (low-energy emulsification method), well-dispersed nanoparticles were formed with no needle structure being observed. The nano-emulsion particles were incorporated well with the glyphosate IPA thus inferring that this nano-emulsion system could ameliorate the bioactivity and bioavailability of the herbicide.