Secondary Amino Research Articles

Intrinsic proclivity of left-handed conformation in large Nest motif peptides inferred from molecular dynamics

The ‘Nest’ motif plays a functional role in protein owing to its ligand binding potential aided by geometric concavity. The presence of less favored left-handed conformation (L-state) in its structure makes this concavity possible and in shaping the native chemical environment amenable to stable binding interactions. To understand the persistent appearance of L-state torsion in the Nest motif, we analyzed 0.5μs Molecular Dynamics (MD) simulation trajectories of 35 six-residue peptides (out of a total of 50 large Nest sequences of ≥6 residues) identified in our previous study. Analysis of the MD trajectories of the individual peptides reveals initial L-state in 60% of the peptides persists for >40% of the trajectory. Further, Nests with different sequences appear to adopt a specific conformational state driven by the neighboring L-state residues. The sequences also possess short secondary structures and amino acid repeats, suggesting evolutionary conservation and the specific role of amino acids in locally predisposing the torsion angle to the L-state. These findings help us to understand how L-state conformation is an essential prerequisite in stabilizing the Nest motif and shed light on the sequence-structure-function paradigm in the rational design of peptides and peptidomimetics for therapeutics. Communicated by Ramaswamy H. Sarma

Delineating host responses induced by Trichoderma in castor through comparative transcriptome analysis

Trichoderma has been recognized as a beneficial fungus to promote crop growth and resistance against pathogens in plants. However, our understanding about the underling molecular mechanism is limited. Delineating the plant's responses to Trichoderma colonization is crucial to understand the molecular basis of their interaction. Therefore, to detect the key differentially expressed genes (DEGs), a pairwise transcriptome analysis was carried at 48 h post inoculation (hpi) between control and Trichoderma-treated roots of castor (Ricinus communis L.). A total of 20,696 plant transcripts were detected using EdgeR software, of which 1508 were DEGs. 474 of these putative DEGs were upregulated while the remaining were downregulated (p < 0.05) in the root samples of the castor genotype, DCS107 treated with Trichoderma asperellum strain 1736. Majority of the DEGs that were downregulated were related to stress, hypersensitive response, reactive oxygen species (ROS), phenylpropanoid pathway, secondary metabolite biosynthesis, carbohydrate and amino acid biosynthesis/metabolism, ABC transporters and transcription factors accompanied by proteins involved in electron transport. Further, to confirm the findings, Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was carried at 12, 24 and 48 hpi for a set of 9 DEGs with a putative role in stress and defense responses. 5 of these genes involved in stress response were found to be downregulated, similar to the transcriptome result. Likewise, the expression of the remaining genes- WRKY71, RPV, ZAT5 and RPS2 with a function in defense were found to be upregulated suggesting that these genes might be playing a crucial role in Trichoderma-mediated responses in castor.

Performance of a high capacity polyamine: Measurement and modeling of the solubility of carbon dioxide in aqueous solutions of 1, 4-bis (3-amino-propyl) piperazine and its heat of absorption

This study focused on measuring the carbon dioxide (CO2) uptake capacity of an amine, 1, 4-Bis (3-aminopropyl) piperazine. The solubility of CO2 was measured at 313.15 K and 333.15 K for three amine concentrations (10, 20, and 30 wt%) of importance in industry and different CO2 partial pressures up to 2.4 MPa. CO2 loadings (mol of CO2/mol amine) were measured using the pressure decay method. At all concentrations, 1,4-Bis(3-aminopropyl) piperazine showed a higher CO2 loading compared to two benchmark amines namely, ethanolamine (MEA) and Piperazine (PZ). The proposed amine had also a higher capacity for CO2 than all other polyamines found in the literature, except, 3, 3 ’-Iminobis (N, N-dimethyl-propylamine) which has two tertiary and one secondary amino group. The experimental measurements were modeled comprehensively with the electrolyte–Non-Random Two Liquid (NRTL) model and the Redlich-Kwong (RK) equation of state (EOS) for the gas phase. The binary NRTL and molecule–ion pair parameters were regressed and reported. The overall percentage of the average absolute deviation (%AAD) between the experimental and estimated values for the temperature, pressure, and mole fractions were 0.12%, 0.07%, and 0.32%, respectively. Finally, the heats of absorption of CO2 in 1, 4-Bis (3-aminopropyl) piperazine were calculated using the Gibbs-Helmholtz equation based on the obtained experimental solubility data. The modeling results for MEA, DEA, and MDEA between the elec-NRTL and the soft-SAFT models were compared. The estimation of the heat of absorptions for the amines was almost the same.

Heterogeneity changes of active bacterial community on cigar filler leaves after fermentation based on metagenome.

Microorganisms play an important role in cigar fermentation. To further explore the dynamic changes of bacterial community composition, the changes of surface bacterial diversity of cigar filler leaves were investigated in the present study by high-throughput sequencing technology. It was found that the surface bacterial richness was declined after fermentation, and the dominant microorganisms on the surface of cigar filler leaves evolved from Pseudomonas spp. and Sphingomonas spp. before fermentation to Staphylococcus spp. after fermentation. The chemical composition and sensory quality evaluation of cigar filler leaves were closely related to the changes of surface bacterial community. The changes of the dominant surface bacterial community led to the differences of metabolic functions, among which the metabolic pathways such as the synthesis of secondary metabolites, carbon metabolism, and amino acid biosynthesis were significantly different. The results provide a basis for clarifying the roles of bacteria in fermentation of cigar filler leaves.

Metabolomics-based exploration the response mechanisms of Saussurea involucrata leaves under different levels of low temperature stress

BackgroundSaussurea involucrata (Sik.) is alpine plant that have developed special adaptive mechanisms to resist adverse environmental conditions such as low temperature chilling during long-term adaptation and evolution. Exploring the changes of its metabolites under different temperature stresses is helpful to gain insight into its cold stress tolerance.MethodsUltra-performance liquid chromatography and tandem mass spectrometry were used to analyze the metabolites in the leaves of Sik. under low different temperature stress conditions. Results: A total of 753 metabolites were identified, and 360 different metabolites were identified according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) involved in the biosynthesis of secondary metabolites and amino acids and sugars. Sucrose and trehalose synthesis, glycolysis, tricarboxylic acid cycle, pentose phosphate pathway, glutamic acid-mediated proline biosynthesis, purine metabolism, amino acid metabolism, phenylpropane synthesis pathway metabolites all respond to low temperature stress. Under cold stress conditions, carbohydrates in Sik. leaves accumulate first than under freezing conditions, and the lower the temperature under freezing conditions, the less amino acids accumulate, while the phenolic substances increase. The expression of various substances in LPE and LPC increased more than 10-fold after low temperature stress compared with the control, but the content of LPE and LPC substances decreased after cold adaptation. In addition, purines and phenolics decreased and amino acids accumulated significantly under freezing conditions. Conclusion: The metabolic network of Sik. leaves under different low temperature stress conditions was proposed, which provided a reference for further exploration of the metabolic mechanism related to low temperature stress tolerance of Sik.

Physiological and transcriptional studies reveal Cr(VI) reduction mechanisms in the exoelectrogen Cellulomonas fimi Clb-11.

A facultative exoelectrogen, Cellulomonas fimi strain Clb-11, was isolated from polluted river water. This strain could generate electricity in microbial fuel cells (MFCs) with carboxymethyl cellulose (CMC) as the carbon source, and the maximum output power density was 12.17 ± 2.74 mW·m-2. In addition, Clb-11 could secrete extracellular chromate reductase or extracellular electron mediator to reduce Cr(VI) to Cr(III). When the Cr(VI) concentration was less than 0.5 mM in Luria-Bertani (LB) medium, Cr(VI) could be completely reduced by Clb-11. However, the Clb-11 cells swelled significantly in the presence of Cr(VI). We employed transcriptome sequencing analysis to identify genes involved in different Cr(VI) stress responses in Clb-11. The results indicate that 99 genes were continuously upregulated while 78 genes were continuously downregulated as the Cr(VI) concentration increased in the growth medium. These genes were mostly associated with DNA replication and repair, biosynthesis of secondary metabolites, ABC transporters, amino sugar and nucleotide sugar metabolism, and carbon metabolism. The swelling of Clb-11 cells might have been related to the upregulation of the genes atoB, INO1, dhaM, dhal, dhak, and bccA, which encode acetyl-CoA C-acetyltransferase, myo-inositol-1-phosphate synthase, phosphoenolpyruvate-glycerone phosphotransferase, and acetyl-CoA/propionyl-CoA carboxylase, respectively. Interestingly, the genes cydA and cydB related to electron transport were continuously downregulated as the Cr(VI) concentration increased. Our results provide clues to the molecular mechanism of Cr(VI) reduction by microorganisms in MFCs systems.

Bench-scale CO2 capture using water-lean solvent of 2-(ethylamino) ethanol, 1-methyl-2-pyrrolidinone, and water

Water-lean amine are promising solvent for CO2 capture to significantly reduce regeneration energy. However, existing water-lean solvent hasn’t been put into commercial application due to high reaction heat, slow CO2 absorption rate, and high amine volatility of amine. In this paper, amines with one secondary amino (—NH), one hydroxyl (—OH), and carbon chain length between 3 and 6 (C3-C6) in structure were preferred for water-lean solvent in the light of amine structure–activity relationship. 2-(ethylamino) ethanol (EMEA) dissolving into 1-methyl-2-pyrrolidinone (NMP) and water were favorable water-lean solvent for CO2 capture, and EMEA/NMP was tested in a bench-scale platform. EMEA/NMP solvents have equivalent CO2 removal efficiencies, and 40–69% lower regeneration energy compared to blended amines and MEA solvents. The lower regeneration energy of EMEA/NMP results from lower water vapor ratio, lower reaction heat, and lower heat capacity. Viscosity of EMEA/NMP at rich loading is 6.92–11.11 mPa·s at 40℃. Increased stripper temperature increases CO2 removal efficiency by decreasing lean loading in EMEA/NMP solvents. CO2 desorption dominates mass transfer in stripper at low temperature while water evaporation dominates at high temperature. The lowest regeneration energy obtained with 5.0 M EMEA/NMP at liquid/gas ratio of 10.5 L/m3 and stripper temperature of 80℃ was 0.99 kWh/kg CO2 (equivalent to 3.6 GJ/tCO2), which is 69% lower than that of 5 M MEA. EMEA/NMP has an increasing amine emission from 109 to 1891 mg/m3 as absorber temperature increases from 34℃ to 54℃. Advanced processes would be employed for volatile amine emission control in future study.

Fully Room Temperature Reprogrammable, Recyclable, and Photomobile Soft Actuators from Physically Cross-Linked Main-Chain Azobenzene Liquid Crystalline Polymers.

Fully room temperature three-dimensional (3D) shape-reprogrammable, recyclable, and photomobile azobenzene (azo) polymer actuators hold much promise in many photoactuating applications, but their development is challenging. Herein, we report on the efficient synthesis of a series of main-chain azo liquid crystalline polymers (LCPs) with such performances via Michael addition polymerization. They have both ester groups and two kinds of hydrogen bond-forming groups (i.e., amide and secondary amino groups) and different flexible spacer length in the backbones. Such poly(ester-amide-secondary amine)s (PEAsAs) show low glass transition temperatures (Tg ≤ 18.4 °C), highly ordered smectic liquid crystalline phases, and reversible photoresponsivity. Their uniaxially oriented fibers fabricated via the melt spinning method exhibit good mechanical strength and photoinduced reversible bending/unbending and large stress at room temperature, which are largely influenced by the flexible spacer length of the polymers. Importantly, all these fibers can be easily reprogrammed under strain at 25 °C into stable fiber springs capable of showing a totally different photomobile mode (i.e., unwinding/winding), mainly owing to the presence of low Tg and both dynamic hydrogen bonding and stable crystalline domains (induced by the uniaxial drawing during the fiber formation). They can also be recycled from a solution at 25 °C. This work not only presents the first azo LCPs with 3D shape reprogrammability, recyclability, and photomobility at room temperature, but also provides some important knowledge of their structure-property relationship, which is useful for designing more advanced photodeformable azo polymers.

Protic ion-crosslinked polymer ionic liquid (PIL) based on linear oligomers

A method for the synthesis of a protic ion-crosslinked polymeric ionic liquid (PIL) which turns into a liquid state at a temperature below 50 °C using a reaction of basic and acidic linear oligomers was developed. The product of interaction of α,ω-diglycidyl ester of oligoethylene oxide MM 1000 with an excess of 1-(3-aminopropyl)imidazole (PEO–2Im) was used as the basic oligomer. It contains two types of basic centers with a significant difference in basicity (aliphatic secondary amino groups and imidazole heterocycles), as well as secondary hydroxyl groups at the ends of oligoether chain. A linear oligomer with terminal sulfonic acid groups (PEO–2SO3H) was obtained by the interaction of of oligoethylene oxide MM 1000 with 2-sulfobenzoic acid cyclic anhydride. Protic ion-crosslinked PIL was synthesized by completely neutralization of basic centers of oligomer PEO–2Im by acidic oligomer PEO–2SO3H at their molar ratio 1:2 respectively. The structure of the obtained PIL was characterized by FTIR and 1Н NMR- spectroscopy methods. According to DSC, the synthesized ion-crosslinked PIL contains two types of crystalline formations with melting temperatures of 36,3 °C and 45,8 °C formed by fragments of oligoethylene oxide during the transfer of protons between different types of ion centers. Determined by the TGA method the temperature of the onset of decomposition, which corresponds to 5% mass loss, is 265 °C. The proton conductivity of the ion-crosslinked PIL was studied by the DRS method in anhydrous conditions in the temperature range from 40 to 100 °C. At a temperature of 100 °C, the proton conductivity is 3,1·10-4 S/cm. The achieved values of proton conductivity and thermal stability make the obtained compound promising as a proton-conducting medium for various electrochemical devices.

Abatement of some commercial fungicide content from model dispersions by a new thiourea-graft-polyethyleneimine derivative

A new derivative of polyethyleneimine (PEI) with 9% degree of substitution of its primary and secondary amino groups with thiourea moieties (TU9-PEI) has been synthesized and investigated as flocculant in model suspensions of commercial fungicide formulations Dithane M45, Melody Compact 49 WG, Cabrio®Top, and their mixtures. The structure of TU9-PEI, obtained by an aqueous one-pot strategy involving formaldehyde mediated coupling of PEI and TU, was confirmed by FTIR and 1H NMR spectroscopy as well as the streaming potential measurements. The settling time, polymer dose, and fungicide type and concentration were the parameters used for assessing the flocculation ability of the new polycation sample. The UV-Vis spectroscopy measurements revealed a good removal efficiency of TU9-PEI for all of the fungicides investigated, between 88 and 94%. Slightly higher removal percent was found for greater fungicide concentrations. The charge neutralization was indicated by zeta potential measurements (values close to zero recorded at the optimum polymer dose) as the main mechanism which contributed to the Dithane and Cabrio®Top particle removal and a combined effect of the TU9-PEI/fungicide particle electrostatic attractions and hydrogen bonds between both the amine and thiourea groups of the polycation chains and the hydroxyl ones on the copper oxychloride particles (negative values) in case of the Melody Compact 49 WG particle separation. Particle size and surface morphology analysis data gave supplementary evidences regarding the TU9-PEI ability to separate the fungicides investigated from simulated wastewater.

Evaluation of phytochemicals and amino acid profiles of four vegetables grown on a glyphosate contaminated soil in Southwestern Nigeria

Abstract Green vegetables are examples of staple plants eating in Nigeria, and are assumed to be a well-off basis of phytochemicals and amino acids that are useful for the management and prevention of infections. However, in the farming of these vegetables, glyphosate-based herbicides (GBH (round up™)) are used as control against pests invasions which has cause reasons to be concern about their effects on the phyto-constituents present in these vegetables. In this study, we evaluated the phytochemicals constituents and amino acid profile of the leaves of Telfairia occidentalis Hook F, Amaranthus viridis Linn, Celosia argentea Linn and Cnidoscolus aconitifolius (Mill.) I. M. Johnst popular edible vegetables in Southwestern Nigeria. The vegetables seeds of these plants mentioned above were acquired from Institute of Agricultural Research and Training (IAR&amp;T) Ibadan. And on a land designed and previously treated with a GBH (round up™) the seeds were planted and allowed to grow. A destructive method of leaves after maturation was achieved by out rightly plucking them out and air-drying under shade. Phytochemical assessments were done on milled plant samples to determine the presence of ten phyto-constituents. Centrifugation of powdered samples (2 g each) with acetonitrile at 1000 rotations per minute’s (rpm) was used to extract amino acids. Thereafter the extracts were individually spotted on a thin layer chromatography (TLC) plate and developed using the mobile phase consisting of methanol: acetic acid: water in ratio 7:2:1 v/v. The visualization for the presence of amino acids was completed by spraying the developed chromatographic plates with 0.5% ninhydrin in 2-propanol solution and observed in both day light and under the ultraviolet lamp and the retention factor (R f ).calculated for the different spots developed to determine the type of amino acids present. The assessment of phytochemicals from the four vegetables reveals the presence of alkaloids, tannins and steroids in all samples while anthraquinone glycosides, terpenoids and cardiac glycosides were absent and other phytochemicals varying in them. Ssaponins was found absent in Telfairia occidentalis and flavonoids in Cnidoscolus aconitifolius respectively. The observation of the TLC plates in daylight shows that the vegetables likely contained primary, secondary and proline amino acids while the calculation of the R f values of the TLC spots observed under an ultraviolet (UV) light indicated that amino acids found in the vegetables were methionine, tyrosine, leucine, isoleucine. However, phenylalanine was found only in Celosia argentea. The study evaluated phytochemicals and amino acids parameters in four leafy vegetables grown on contaminated glyphosate based herbicide soil and assessments shows that their medicinal properties were not altered with the minimal exposure to contaminant.

Enhancing Top-Down Characterization of Membrane Proteoforms with C8-Functional Amine-Bridged Hybrid Monoliths.

Comprehensive characterization of membrane proteins at the level of proteoforms in complex biological samples by top-down mass spectrometry (MS) is of vital importance in revealing their precise functions. However, severe peak broadening in the separation of hydrophobic membrane proteins, caused by resistance to mass transfer and strong adsorption on separation materials, leads to MS spectra overlap and signal suppression, which makes against the in-depth research on membrane proteoforms. Herein, C8-functional amine-bridged hybrid monoliths with an interconnected macroporous structure were developed by the in situ one-step sol-gel reaction of triethoxy(octyl)silane and bis[3-(trimethoxysilyl)propyl]amine in capillaries. Due to the unique macroporous structure and bridged secondary amino groups in the framework, the monolith possessed reduced resistance to mass transfer, low nonspecific adsorption, and electrostatic repulsion to membrane proteins. These features tremendously alleviated peak broadening in the separation of membrane proteins, thus outperforming traditional reversed-phase columns in top-down characterization of membrane proteoforms. With this monolith, a total of 3100 membrane proteoforms were identified in the mouse hippocampus, representing the largest membrane proteoform database obtained by top-down analysis so far. The identified membrane proteoforms revealed abundant information, including combinatorial post-translational modifications (PTMs), truncation, and transmembrane domains. Furthermore, the proteoform information was integrated into the interaction network of membrane protein complexes involved in oxidative phosphorylation processing, opening up new opportunities to uncover more detailed molecular basis and interaction in the biological processes.

Chalcopyrite-activated sodium percarbonate oxidation for sludge dewaterability enhancement: Synergetic roles of •OH and 1O2

Efficient dewatering of sewage sludge is an energy- and carbon-saving procedure of sludge treatment in wastewater treatment facilities. Due to the limiting factors of hydrophilic extracellular polymeric substances, it is crucial to weaken the water-holding capacity and hydrophilicity for high-performance sludge-water separation. The current study successfully put forward a combination process of chalcopyrite + sodium percarbonate (SPC) to proficiently facilitate sludge dewaterability. Results showed that after the optimized treatment, the water removal efficiency augmented from 51.3 to 94.9%, while the water content of sludge cake declined from 90.1 to 52.0 wt%. Mechanism investigation demonstrated that the chalcopyrite + SPC system could consecutively generate reactive oxygen species via strong Fe3+/Fe2+ and Cu2+/Cu+ conversion cycles. The dominant reactive radical •OH and non-radical 1O2 could effectively degrade the macromolecular EPS into low-molecular biopolymers, decrease the high-polarity hydrophilic protein secondary structure and amino acids, and further reduce water-holding interfacial affinity. Afterward, the electrostatic force and interfacial free energy were decreased and turned out to enhance self-flocculation and flowability. Accordingly, bound water reduction and sludge-water separation efficiency were promoted. Furthermore, the chalcopyrite + SPC system could be viewed as a surrogate to Fenton/Fenton-like strategies for sludge dewaterability with economic advantage and low environmental risk. These findings inspire the application prospect of the chalcopyrite + SPC conditioning technique, which expects to save energy and reduce carbon emissions.

New High-Performance Fluorescent Dye Scaffolds: Applications for Bioimaging and Biosensing

AbstractFluorescence imaging in the shortwave infrared region (SWIR, 850–2500 nm) window has become an indispensable tool in biomedical research because it has weaker absorption, less light scattering, and less background fluorescence in this window. As we know, the design and synthesis of fluorescent dyes and fluorescent probes are the cores of fluorescence imaging and biosensing. Thus, their photophysical mechanisms exploring and bioanalytical applications are multidisciplinary and cutting-edge research topics. In this regard, we have been working on high-performance fluorescent dyes and fluorescent probes for years. In short, we have developed a series of bright, stable, aggregation-resistant, SWIR fluorescent dyes ECXs, based on a carbon-bridged spiro ring strategy. We also developed a series of high-performance SWIR fluorescent dyes CXs and Chrodols, which combine the structural advantages of cyanine and xanthenoid dyes. Based on these new SWIR scaffolds, we further constructed some activatable SWIR fluorescent probes with OFF-ON or ratiometric properties for biosensing in vivo. Therefore, the main line of our work is to gain an in-depth understanding of the photophysical mechanisms of fluorescent dyes, to create high-performance luminescent dyes, and to further develop fluorescent probes for bioimaging and biosensing.1 Introduction2 ECX Dyes Based on a Carbon-Bridged Spiro Ring Strategy3 Fluorescent Dyes and Fluorescent probes Combining the Structures of Cyanine and Xanthenoid Dyes3.1 CX Series Dyes3.2 A Functionalized Modified CX probe NRh3.3 CX-like Dyes with a Secondary Amino Py-23.4 Chrodol Series Dyes4 Conclusion and Future Prospects

Abiotic Stress in Crop Production.

The vast majority of agricultural land undergoes abiotic stress that can significantly reduce agricultural yields. Understanding the mechanisms of plant defenses against stresses and putting this knowledge into practice is, therefore, an integral part of sustainable agriculture. In this review, we focus on current findings in plant resistance to four cardinal abiotic stressors-drought, heat, salinity, and low temperatures. Apart from the description of the newly discovered mechanisms of signaling and resistance to abiotic stress, this review also focuses on the importance of primary and secondary metabolites, including carbohydrates, amino acids, phenolics, and phytohormones. A meta-analysis of transcriptomic studies concerning the model plant Arabidopsis demonstrates the long-observed phenomenon that abiotic stressors induce different signals and effects at the level of gene expression, but genes whose regulation is similar under most stressors can still be traced. The analysis further reveals the transcriptional modulation of Golgi-targeted proteins in response to heat stress. Our analysis also highlights several genes that are similarly regulated under all stress conditions. These genes support the central role of phytohormones in the abiotic stress response, and the importance of some of these in plant resistance has not yet been studied. Finally, this review provides information about the response to abiotic stress in major European crop plants-wheat, sugar beet, maize, potatoes, barley, sunflowers, grapes, rapeseed, tomatoes, and apples.

Ultrasound-assisted alkaline extraction of protein from Tenebrio molitor larvae: Extraction kinetics, physiochemical, and functional traits

Currently, as a promising alternative protein source, the interest of edible insect protein has been continuously increased. However, the extraction processing had distinct effects on the physicochemical properties and functionalities of this novel and sustainable protein. In this study, Tenebrio molitor larvae protein (TMLP) was extracted via ultrasound (US)-assisted alkaline extraction. The changes of extraction kinetics, physicochemical characteristics, and functional properties of TMLP as a function of US time (10, 20, 30, 40, 50 min) were investigated. The results showed that 30 min US treatment rendered the maximum protein yield (60.04 %) (P < 0.05). Meanwhile, Peleg's model was considered a suitable model to represent the extraction kinetics of TMLP, with a correlation coefficient of 0.9942. Moreover, the protein secondary structure, particle size, and amino acid profiles of TMLP were changed under the US-assisted alkaline extraction process. Additionally, a significant improvement of the functional properties of TMLP extracted with this method was observed compared to traditional alkaline extraction. In conclusion, the present work suggests that US-assisted alkaline extraction could be considered as a potential method to improve the protein yield, quality profiles, and functional properties of TMLP.

Effect of amino acids on growth, elemental content, functional groups, and essential oils composition on hydroponically cultivated coriander under different conditions

Amino acids act as crucial growth promoters by improving plant metabolism. Coriander is an herbaceous plant mainly cultivated from fruits. The present study objective was to analyze the effect of amino acids solution on growth, elemental content, chlorophyll, carotenoid, amino acids, and essential oils profile of coriander cultivated hydroponically under board range red & blue (BRB) and white light. The experiments were done in three sets, with three different concentrations (0, 100, & 200 ppm) of amino acid solution. The incorporation of amino acids into the nutrient solutions stimulates the nearly 20% morphological changes in the coriander plant, especially at 100 ppm in an aqueous medium in BRB light condition. The quantitative values of the 23% nitrogen, 18% phosphorous, 31% potassium, 44% magnesium, 16% iron, 76% sodium, 16% nickel, and 143% zinc in hydroponically cultivated coriander were higher at 100 ppm of amino acids solution. The use of 100 ppm amino acids solution in the nutrients used for hydroponics witnessed radical enhancement in the chlorophyll and carotenoid content and diversity of functional groups in coriander. The hydroponically cultivated coriander at 100 ppm of amino acid solution under BRB light allowed the synthesis of a higher amount of many amino acid accumulations. Plants cultivated at 100 ppm amino acids solutions contained more aromatic monoterpenes and higher linalool content (59.71%). Our study concluded that coriander cultivated at 100 ppm of an amino acid solution under BRB light condition had a positive impact on plant growth, primary and secondary metabolic accumulation Amino acids increase the plant growth, elemental content, chlorophyll, carotenoid, amino acids, and essential oils profile of coriander.

Structure–Property Relationships in Epoxyurethane Polymers Based on Erythritol Dicarbonate

AbstractThe highly reactive erythritol dicarbonate (EDC) allows facile design and preparation of solvent‐ and catalyst‐free epoxyurethane polymers. Diglycidyl ether of bisphenol‐A (DGEBA) and oligo polyhydroxyurethanes are used to produce epoxyurethane polymers (o‐PHUs). The o‐PHUs are prepared using cyclic carbonates derived from erythritol and various diamines (aliphatic amine and polyether amine) or polyamines (diethylene triamine (DETA) and triethylne tetramine (TETA)). Active secondary amino groups derived from o‐PHUs polyamines form hydrogen bonds between urethane carbonyls in epoxy hybrid networks with the highest cross‐linking density (1293 mol m−3), glass transition temperature Tg (93 °C), and ultimate tensile strength (34 MPa). And the ether bond provides a significant potential for hydrogen bonding between hydroxyl group and ether oxygen, forming strong hydrogen bond cross‐linking between molecular chains, with cross‐linking density and ultimate tensile strength comparable to polyepoxyurethane derived from polyamines, except for a lower Tg (27 °C). In addition, these polyepoxyurethanes have superior adhesion to wood, aluminum alloy, and polymethyl methacrylate (PMMA) substrates. This versatile oligo PHUs would provide a wide range of fabrication options for adhesive epoxyurethane polymers.

Alkylation of N,N-Dibenzylaminoacetonitrile: From Five- to Seven-Membered Nitrogen-Containing Heterocyclic Systems.

The syntheses of several alkaloids and nitrogen-containing compounds including N-Boc-coniine (14b), pyrrolizidine (1), δ-coniceine (2), and pyrrolo[1,2a]azepine (3) are described. New C-C bonds in the α position relative to the nitrogen atom were formed by the alkylation of metalated α-aminonitriles 4 and 6a-c with alkyl iodides possessing the requisite size and functionality. In all of the reported cases, the pyrrolidine ring was formed in the aqueous medium through a favorable 5-exo-tet process involving a primary or a secondary amino group and a terminal δ-leaving group. Conversely, the azepane ring was efficiently formed in N,N-dimethylformamide (DMF), as the preferred aprotic solvent, through an unreported 7-exo-tet cyclization process involving a more nucleophilic sodium amide and a terminal mesylate borne by a saturated six carbon chain unit. In this way, we successfully synthesized pyrrolo[1,2a]azepane 3 and 2-propyl-azepane 14c in good yields from inexpensive and readily available materials without tedious separation methods.

Synergism of mixed cationic collectors in the flotation of quartz unveiled by AFM, solution chemistry and quantum chemical calculations

The considerable increase in worldwide demand for iron ore requires more studies for efficiency of silicate gangue flotation. New reagents and synergistic mixtures have been pursued to tackle this technological problem. Although there are several studies of collector mixtures in the literature, very few were dedicated to mixtures of cationic collectors. To fill such gap, the interaction between ethermonoamine (M) and etherdiamine (D) was evaluated using bench flotation tests with a typical Brazilian iron ore, solution chemistry analysis and density functional theory calculations (DFT) for the first time in literature. The combined use of these collectors in the proportion 3 D: 1 M, w/w, at pH 10.5, provided the best recovery and selectivity, showing synergism. The iron recovery was 83.9% with a rougher concentrate presenting an iron and silica content of 64.0% and 4.6%, respectively. Differences in the pKa values of primary and secondary amino groups point to minimization of electrostatic repulsion between adsorbed collectors. Interaction free energy values indicate that the complexes M(0)-D(+) (−8.29 kcal/mol), D(0)-D(+) (−7.74 kcal/mol) and M(+)-D(0) (−8.66 kcal/mol) are the most thermodynamically favored and, therefore, confirm the experimental results and explain the nature of the favorability, which is related to the reorganization of the collectors in order to minimize ether-ether and cation-cation repulsion and maximize ether-amine or amine–amine neighbors, especially when the amino group is protonated.