Quick Synthesis Research Articles

Conducting a rapid review for quick turnaround knowledge synthesis

Conducting a rapid review for quick turnaround knowledge synthesis

Quick synthesis of isatin-derived knoevenagel adducts using only eco-friendly solvent

A variety of knoevenagel compounds from isatin were synthesized using an eco-friendly methodology. It was used only the binary solvent ethanol: water (3:7 v/v) without the presence of metal catalyst what enabled the reaction between different isatins with malononitrile in a quick reaction time of 2–5 min and isolated yields 80–96%. When cyanoesters were used as methylene actives, the reactions were longer and the knoenevagel products were obtained 79–92% isolated yields.

Green Synthesis of Silver Nanoparticles Using Nymphae odorata Extract Incorporated Films and Antimicrobial Activity

Silver nanoparticles (AgNPs) synthesis was formulated by the green method using Nymphae odorata plant extract as reducing and capping agent. Plants offer a good platform for synthesizing nanoparticles (NPs) which can act as a non-toxic, natural capping/reducing agent and can convert Ag+ to Ag0. The 5 min reduction time (the extract contains a lot of reduction agents, which leads to quick synthesis and such can be a great advantage) is a best experimental condition for the effective biological synthesis of AgNPs. Sodium alginate films were doped by these NPs. The antimicrobial study of AgNPs and doped films were examined by Staphylococcus aureus and Escherichia coli. As a result, at very low concentration of about 25 µl of AgNPs was found to inhibit the entire bacterial strains studied and films also showed a similar result. The results confirmed the effectiveness of prepared AgNPs and films as an antibacterial agent. Hence, it can be used for nano-biotechnology, biomedical and industrial applications.

Microwave-assisted one-pot quick synthesis of 1-monosubstituted 1,2,3-triazoles from arylboronic acids, sodium azide and 3-butyn-2-ols

Microwave-assisted one-pot quick synthesis to 1-monosubstituted 1,2,3-triazoles was achieved with good to excellent yields using the widely available arylboronic acids, sodium azide and 3-butyn-2-ols within 15 min. This method features high efficient and facile as organic azides, acetylene gas and harsh conditions were avoided. Microwave-assisted one-pot quick synthesis to 1-monosubstituted 1,2,3-triazoles was achieved with good to excellent yields using the widely available arylboronic acids, sodium azide and 3-butyn-2-ols within 15 min.

Palladium‐Catalzyed Atroposelective 16‐Membered Macrocyclization: Total Synthesis of Isoplagiochin D†

Summary of main observation and conclusionIsoplagiochin D is a ring‐strained macrocyclic bisbibenzylis, which showed stable axial chirality in one biaryl structure, and semistable axial chirality in the other biaryl moiety. We reported here an unprecedented example for the catalytically asymmetric synthesis of ring‐strained atropisomers via Pd‐catalyzed macrocyclization between benzyl halides and carbenes. This newly developed Pd‐catalyzed asymmetric macrocyclization protocol enabled us a quick synthesis of isoplagiochin D in a highly enantioselective manner.

Columnas, tartas y un italiano ilustre. Representación gráfica de variables cualitativas.

La estadística descriptiva es aquella rama de la estadística que utilizamos habitualmente para obtener una primera aproximación a los resultados de nuestro estudio. Con frecuencia se recurre a la representación gráfica de las variables para conseguir una síntesis rápida más sencilla de comprender. Se revisan los tres gráficos más utilizados para la representación de las variables cualitativas. ABSTRACT Columns, pies and an illustrious Italian. Graphical representation of qualitative variables. Descriptive statistics is that branch of statistics that we usually use to obtain a first approximation of the results of our study. Frequently, graphic representation of variables is used to achieve a quick synthesis that is easier to understand. We review the three most frequently used graphs for the representation of qualitative variables.

Speedy ceramic sintering

Ceramics Synthesizing ceramics can require heating for long times at high temperatures, making the screening of high-through-put materials challenging. C. Wang et al. developed a new ceramic-sintering technique that uses resistive heating of thin carbon strips to ramp up and ramp down temperature quickly. This method allows for the quick synthesis of a wide variety of ceramics while mitigating the loss of volatile elements. Ultrafast sintering is ideal for synthesizing many compositions to screen for ideal properties for a variety of applications, including the development of new solid-state electrolytes. Science , this issue p. [521][1] [1]: /lookup/doi/10.1126/science.aaz7681

A general method to synthesize and sinter bulk ceramics in seconds.

Ceramics are an important class of materials with widespread applications because of their high thermal, mechanical, and chemical stability. Computational predictions based on first principles methods can be a valuable tool in accelerating materials discovery to develop improved ceramics. It is essential to experimentally confirm the material properties of such predictions. However, materials screening rates are limited by the long processing times and the poor compositional control from volatile element loss in conventional ceramic sintering techniques. To overcome these limitations, we developed an ultrafast high-temperature sintering (UHS) process for the fabrication of ceramic materials by radiative heating under an inert atmosphere. We provide several examples of the UHS process to demonstrate its potential utility and applications, including advancements in solid-state electrolytes, multicomponent structures, and high-throughput materials screening.

Long-Distance Cooperative and Antagonistic RNA Polymerase Dynamics via DNA Supercoiling

Genes are often transcribed by multiple RNA polymerases (RNAPs) at densities that can vary widely across genes and environmental conditions. Here, we provide in vitro and in vivo evidence for a built-in mechanism by which co-transcribing RNAPs display either collaborative or antagonistic dynamics over long distances (>2 kb) through transcription-induced DNA supercoiling. In Escherichia coli, when the promoter is active, co-transcribing RNAPs translocate faster than a single RNAP, but their average speed is not altered by large variations in promoter strength and thus RNAP density. Environmentally-induced promoter repression reduces the elongation efficiency of already-loaded RNAPs, causing premature termination and quick synthesis arrest of no-longer-needed proteins. This negative effect appears independent of RNAP convoy formation and is abrogated by topoisomerase I activity. Antagonistic dynamics can also occur between RNAPs from divergently-transcribed gene pairs. Our findings may be broadly applicable given that transcription on topologically-constrained DNA is the norm across organisms.

Quick synthesis of homogeneous Nb2O5 nanorod arrays via a microwave-assisted hydrothermal method

Homogeneous nanostructures of Nb2O5 were synthesized rapidly using a microwave-assisted hydrothermal method. Niobium plates were used as raw materials without the addition of corrosive HF nor any directing agent. The composition and morphology of the structures were determined by scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–vis and Raman spectroscopies. The results show that microwave irradiation reduced synthesis time from several days to 2 h. SEM images reveal the formation of structured nanorod arrays at 200 °C. The optical band gap of the nanorods suggests a large-gap semiconducting behavior. These results indicate that the microwave-assisted hydrothermal method is a fast and cheaper technique for the production of homogeneous Nb2O5 nanorod arrays.

Removal of metal ions Cd(II), Cr(VI) and Ni(II) from aqueous solution using an organic aerogel and carbon aerogel obtained by acid catalysis

In this work, we evaluated the adsorption capacity of the metal ions Cd(II), Cr(VI) and Ni(II) from aqueous solution of an organic aerogel, a carbon aerogel and a commercial activated carbon. Aerogel (Ae) was obtained by acid catalysis using HCl, achieving a quick synthesis, then, a process of carbonization to obtain the carbon aerogel (CAe) was performed. Structural, textural and chemical parameters of the porous solids obtained were characterized by different experimental techniques: scanning electron microscopy (SEM), adsorption isotherms of N2 at 77 K and CO2 at 273 K, Boehm titrations and pHPZC determination. The three adsorbents were employed in simple adsorption systems of Ni(II), Cd(II) and Cr(VI) from aqueous solution. It was determined that the synthesized aerogel is the material that performed the highest adsorption capacity of the three metal ions: Ni (32.2 mg g–1) Cd (18.6 mg g–1) and Cr (35.5 mg g–1).

Stable Colloidal Silica Particles Doped with a Fluorescent Dye

In this study, we described the quick synthesis strategy of stable colloidal silica particles encapsulated with a fluorescent dye. Atomic Force Microscopy AFM, Fourier-Transform Infrared Spectroscopy FTIR, and Fluorescence Spectroscopy FS were utilized to characterize the obtained silica particles. AFM analysis revealed that obtained silica particles have a spherical shape with a mean size of 210 ± 13 nm. FS analysis showed that fluorescent dye was successfully incorporated into a silica matrix. In particular, eye-visible green fluorescence emission with a peak maximum at 526 nm was detected. The emission stability of prepared particles was tested in a biologically-relevant pH range, under constant UV irradiation and at different storage time intervals.

Long-Distance Cooperative and Antagonistic RNA Polymerase Dynamics via DNA Supercoiling.

Genes are often transcribed by multiple RNA polymerases (RNAPs) at densities that can vary widely across genes and environmental conditions. Here, we provide invitro and invivo evidence for a built-in mechanism by which co-transcribing RNAPs display either collaborative or antagonistic dynamics over long distances (>2 kb) through transcription-induced DNA supercoiling. In Escherichia coli, when the promoter is active, co-transcribing RNAPs translocate faster than a single RNAP, but their average speed is not altered by large variations in promoter strength and thus RNAP density. Environmentally induced promoter repression reduces the elongation efficiency of already-loaded RNAPs, causing premature termination and quick synthesis arrest of no-longer-needed proteins. This negative effect appears independent of RNAP convoy formation and is abrogated by topoisomerase I activity. Antagonistic dynamics can also occur between RNAPs from divergently transcribed gene pairs. Our findings may be broadly applicable given that transcription on topologically constrained DNA is the norm across organisms.

A facile microwave synthesis of rGO, ZrO2 and rGO–ZrO2 nanocomposite and their room temperature gas sensing properties

Microwave irradiation technique provides a simple and quick synthesis route for nanomaterials at controlled experimental conditions. In this view, nanostructures of rGO, ZrO2, and rGO–ZrO2 composite were synthesized using microwave synthesis technique. Herein, we experimented the preparation of rGO using optimized conditions using convection mode at 373 K in a commercial microwave oven. Structural properties revealed the formation of mixed phases of the orthorhombic and rhombohedral crystal structure of ZrO2. The preferential plane orientation was found to be in c-axis (002) for rGO–ZrO2 nanocomposite, which revealed the predominance of rGO in the nanocomposite. Morphology of the prepared nanostructures exhibited agglomerated sheets, denser nanograins and randomly aggregated nanosheets for rGO, ZrO2, and mixed nanocomposite respectively. Room temperature gas sensing properties of the prepared nanostructures were investigated and reported. rGO showed responses of 5.3 and 5.2 towards 200 ppm of trimethylamine (TMA) and methanol. ZrO2 nanostructure showed a response of 35 towards 200 ppm of ammonia with response–recovery times of 91 and 6 s.

Mechanochemical enzymatic synthesis of 1,4‐dihydropyridine calcium antagonists and derivatives

AbstractBACKGROUNDEnzyme promiscuity has attracted significant attention from chemists and biochemists in recent years. However, long reaction time and use of toxic organic solvents limit its applications for industrial processes. 1,4‐Dihydropyridine (1,4‐DHP) calcium antagonists are recommended for the first line treatment of hypertension. Although some chemical protocols for the preparation of 1,4‐DHP calcium antagonists have been developed, enzymatic synthesis of these compounds still remains uncovered.RESULTSSolvent‐free quick synthesis of 1,4‐DHP calcium antagonists felodipine, nitrendipine, nifedipine and nemadipine B and their derivatives was achieved by Lipozyme® RM IM (triacylglycerol acylhydrolase, EC3.1.1.3)‐catalyzed multicomponent reactions of aromatic aldehyde, alkyl acetoacetate and alkyl 3‐aminocrotonate under ball‐milling conditions. The products were obtained in moderate yields (up to 86.8%) and the influence of reaction conditions including catalyst loading, grinding auxiliary and grinding frequency was investigated.CONCLUSIONThe protocol successfully overcame some longstanding problems in the field of enzymatic promiscuity research, such as long reaction time and use of harmful organic solvents, and demonstrated the potential application value of promiscuous enzyme‐catalyzed reactions under ball‐milling conditions for pharmaceutical synthesis. © 2019 Society of Chemical Industry

<p>Quick synthesis of a novel combinatorial delivery system of siRNA and doxorubicin for a synergistic anticancer effect</p>

Purpose: Combining siRNA and other chemotherapeutic agents into one nanocarrier can overcome the multidrug resistance (MDR) phenomenon by synergistically MDR relative genes silencing and elevated chemotherapeutic activity. Most of these systems are typically fabricated through complicated procedures, which involves materials preparation, drug loading and modifications. Herein, the purpose of this study is to develop a new and fast co-delivery system of siRNA and doxorubicin for potentially synergistic cancer treatment.Methods: The co-delivery system is constructed conveniently by a stable complex consisting of doxorubicin bound to siRNA via intercalation firstly, followed by interacting with (3-Aminopropyl)triethoxysilane (APTES) electrostatically and Tetraethyl orthosilicate (TEOS) co-condensed, and the characterizations of the resultant nanocarrier are also investigated. Furthermore, this study evaluates the synergistic anti-cancer efficacy in MCF-7/MDR cells after treatment of siRNA and doxorubicin ‘two in one’ nanocarriers.Results: We establish a new and fast method to craft a co-delivery system of siRNA and doxorubicin with controllable and nearly uniform size, and the entire fabrication process only costs in about 10 minutes. The resultant co-delivery system presents high loading capacities of siRNA and doxorubicin, and the encapsulated doxorubicin plays a pH-responsive control release. Further, biological functionality tests of the synthesized co-delivery nanocarriers show high inhibition of P-gp protein encoded by MDR-1 gene in MCF-7/MDR cells (a variant of human breast cancer cell line with drug resistance) after transfection of these nanocarriers carrying MDR-1 siRNA and doxorubicin simultaneously, which sensitize the MCF-7/MDR cells to doxorubicin, overall leading to improved cell suppression.Conclusion: Collectively, this co-delivery system not only serves as potent therapeutics for synergistic cancer therapy, it also may facilitate the bench-to-bedside translation of combinatorial delivery system as a robust drug nanocarrier by allowing for fabricating a simply and fast nanocarrier for co-delivery of siRNA and doxorubicin with predictable high production rate.

Facile Synthesis of Pt Icosahedral Nanocrystals with Controllable Sizes for the Evaluation of Size‐Dependent Activity toward Oxygen Reduction

AbstractPlatinum icosahedral nanocrystals are intriguing catalytic materials owing to the presence of a large number of twin boundaries and well‐defined {111} facets on the surface. However, there are only two protocols available for their synthesis and the protocols required either the involvement of a metal carbonyl as the reductant or a very long reaction time up to one week. Here we report a facile route to the quick synthesis of Pt icosahedral nanocrystals with tunable sizes. The synthesis only involved Pt(acac)2, tetraethylene glycol, poly(vinyl pyrrolidone), and as the metal precursor, solvent/reductant, and colloidal stabilizer, respectively. Noticeably, the synthesis could be completed within 20 min. By simply varying the amount of the precursor, we were able to tune the size of the Pt icosahedral nanocrystals in the range of 10–25 nm. Additionally, when ascorbic acid was introduced as a co‐reductant to facilitate the reduction of the precursor, the size of the Pt icosahedral nanocrystals could be further reduced down to 7–12 nm. When used as a catalyst towards the oxygen reduction reaction, the Pt icosahedral nanocrystals with different sizes all exhibited a specific activity more than 2.4 times greater than that of commercial Pt/C. Moreover, their specific activity increased with the particle size. After 5,000 cycles of the accelerated durability test, the specific activities of the Pt icosahedral nanocrystals with three different sizes were still more than 2 times as high as that of the commercial Pt/C catalyst.

Quick synthesis of fluorescent nitrogen-doped carbon nanoparticles for selective and sensitive Fe(III) detection in water

Recently, fluorescent carbon nanostructures have attracted enormous attention thanks to their excellent optical properties, low-cost, chemical inertness and stability. In this study, we demonstrated a quick, facile, environment-friendly and low-cost synthesis method for the preparation of fluorescent nitrogen-doped carbon nanoparticles (N-CNPs). Prepared N-CNPs have excitation-dependent fluorescent properties and demonstrate high selectivity towards Fe(III) ions in water. We found that prepared N-CNPs can be used for sensitive detection of Fe(III) ions in the range of 1–30 ppm. Thus, fluorescent N-CNPs can be a promising material for fast and low-cost analysis of Fe(III) ions in water.

Biogenic synthesis of silver palladium bimetallic nanoparticles from fruit extract of Terminalia chebula – In vitro evaluation of anticancer and antimicrobial activity

Biogenic synthesis of nanoparticles used for biomedical application has received much attention nowadays owing to its quick synthesis, cost effectiveness and biocompatible nature. The present study focuses on the biosynthesis of silver palladium bimetallic nanoparticles (AgPd NPs) from aqueous fruit extract of Terminalia chebula. Synthesized AgPd NP was assessed for antimicrobial activity and anticancer potential against lung cancer cells (A549). XRD analysis confirmed the formation of face centered cubic crystalline structure with average size of 20 nm, which was affirmed by DLS analysis. Uniform spherical shaped nanoparticles were observed in SEM and TEM analysis. Zeta potential value of −14.4 mV illustrated the stability of AgPd NPs. Anticancer studies illustrated that AgPd NPs induced ROS generation in lung cancer cells, thereby stimulating mitochondrial apoptotic pathway causing cell death. AgPd NPs exhibited antimicrobial activity against methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa. In vitro toxicity studies revealed that AgPd NPs exhibited no cyototoxic and hemolytic effect upto its maximum dose (200 μg/ml), ensuring the biocompatibility of nanoparticles. Our findings demonstrated that aqueous extract of T. chebula act as effective reducing and stabilizing agent for green synthesis of biocompatible AgPd NPs, which exhibits potent antimicrobial and anticancer activities.

Approach to Fully Substituted Cyclic Nitrones from N‐Hydroxylactam Derivatives: Development and Application to the Total Synthesis of Cylindricine C

AbstractAn approach to cyclic nitrones from N‐hydroxylactam derivatives is documented. The nucleophilic addition of an organolithium reagent to an N‐OSEM [SEM=2‐(trimethylsilyl)ethoxymethyl] lactam forms a five‐membered chelated intermediate, which undergoes both elimination and deprotection to give a fully substituted nitrone in a one‐pot process. When combined with the N‐oxidation of easily available chiral lactams, this method becomes especially useful for the quick synthesis of chiral nitrones in enantio‐pure form, enabling the concise total synthesis of cylindricine C.