jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Takumi Yamamoto | Daisuke Aoki | K. Mikami | Hideyuki Otsuka
Source: ChemRxiv (preprint, 2023-10-12)
Field: Materials Science — Materials Chemistry

Diverse Metastable Diarylacetonitrile Radicals Generated by Polymer Mechanochemistry Fluorescent radicals have attracted great attention as luminescent materials, mostly on account of their potential to achieve higher luminescence efficiency than closed-shell molecules. However, analyzing fluorescent radicals at ambient conditions remains a challenging task, because radicals are usually unstable in air. In addition, to the best of our knowledge, research aimed at controlling fluorescence wavelengths through substituent changes has not yet been accomplished. Here, we report diverse metastable diarylacetonitrile (DAAN) radicals, which contain different substituents, generated by polymeric mechanochemical reactions. The DAAN radicals, generated by ball-milling powdered polystyrene together with DAAN derivatives, were dispersed within the polystyrene matrix, where they retained their radical state, which allowed measuring solid-state fluorescence spectra. These measurements revealed that a wide range of fluorescence wavelengths from green to red (λem,max = 517–635 nm) can be achieved only by changing the substituents on the aromatic rings in these DAAN radicals. This phenomenon has not been observed for the well-studied triarylmethyl radicals. The fluorescence wavelength of these DAAN radicals can be precisely estimated by time-dependent density-functional theory (TD-DFT) calculations. The amount of DAAN radicals generated upon ball-milling is discussed in conjunction with DFT calculations and experimental results. Our results suggest that the orbital interactions with polymeric mechanoradicals, the bond-dissociation enthalpy, and the steric protection of the radical center are of paramount importance for the generation of DAAN radicals. The results of this study can be expected to provide useful guidelines for the development of advanced fluorescent radicals. Radical ; Photochemistry ; Fluorescence ; Mechanochemistry ; Chemistry ; Polymer ; Dissociation (chemistry) ; Photodissociation ; Metastability ; Physical chemistry ; Organic chemistry Luminescence and Fluorescent Materials ; Organic Light-Emitting Diodes Research ; Electron Spin Resonance Studies
Authors: M Lavanya | Aishwarya S. Suvarna | P. Preethi Kumari
Source: Research Square (preprint, 2023-03-29)
Field: Materials Science — Materials Chemistry

Adsorption and corrosion inhibition behavior of Pterocarpus marsupium stem extract on mild steel in acid medium: Experimental and Statistical approach Abstract The present work emphasizes the corrosion mitigation behavior of Pterocarpus marsupium stem extract (PMSE) on mild steel (MS) in various concentrations of hydrochloric acid (HCl) solution using an electrochemical technique. The experiments were conducted in three different levels of acid concentrations (0.1, 0.25, and 0.5 M), three levels of inhibitor concentration (0.03, 0.12 and 0.24 g/L), and at three different temperatures (303 to 313 K) and optimized to get maximum inhibition efficiency. The inhibition efficiency increased with an increase in PMSE concentrations in all the acid concentrations and decreased with an increase in temperature. The Tafel polarization technique revealed mixed inhibition behaviour of PMSE with maximum inhibition efficiency (% IE) of 88.9 % at 303 K containing 0.24 g/L of PMSE in 0.1 M HCl solution. The adsorption mechanism of PMSE on the surface of MS is consistent with physisorption by obeying Freundlich’s adsorption isotherm. The corrosion inhibition of PMSE predominantly owing to protective film formation on the metal surface and is confirmed by surface morphological and FTIR spectral studies. RSM studies using the Taguchi method revealed the highest inhibition efficiency to be predicted at minimum temperature and acid concentration and at the maximum inhibitor concentration as obtained in the experiments. Tafel equation ; Physisorption ; Adsorption ; Chemistry ; Hydrochloric acid ; Corrosion ; Freundlich equation ; Nuclear chemistry ; Electrochemistry ; Inorganic chemistry ; Chromatography ; Organic chemistry ; Electrode ; Physical chemistry Corrosion Behavior and Inhibition ; Concrete Corrosion and Durability ; Electrodeposition and Electroless Coatings
Authors: I.N. Anuarbekova | Ye.S. Sychyeva | D.B. Markina | M. S. Mukanova
Source: Chemical Journal of Kazakhstan (article, 2023-09-15)
Field: Chemistry — Organic Chemistry

SYNTHESIS AND BIOLOGICAL ACTIVITY OF NEW MORPHOLIN-CONTAINING THIOANHYDRIDES Morpholine is a promising and versatile six-membered heterocycle, a popular pharmacophore with a wide spectrum of biological and pharmacological activity. The purpose of this work is the synthesis of biologically active compounds, based on 3-morpholinepropylamine, the determination of the structure and biological activity of the synthesized compounds. Results and discussion. Acetic, propionic, benzoic, 4-chlorobenzoic and 2,4-dichlorobenzoic 3-morpholinopropylcarbamothioic thioanhydrides have been synthesized as a result of acylation of sodium 3-morpholylpropylcarbadithioate with the corresponding acid’s chlorides. The synthesis has been carried out in acetone at the room temperature for 2 – 3 h. The structure of the synthesized compounds has been established on the basis of the elemental analysis data, IR spectra, 1Н and 13С NMR spectroscopy. Conclusion. As a result of the laboratory and field tests, it has been found that the use of morpholinopropylcarbamothioic thioanhydrides contribute to an increase in the seed shoot formation of wheat and spruce. Propionic 3-morpholinopropylcarbamothioic thioanhydride activates at a concentration of 0.01% the seedlings length of wheat seeds up to 5.1 cm and increases the germination of shoots up to 88%, and on spruce seeds, the seedlings length is 7.3 cm and the germination of shoots is 87% as compared with the control (4.4 cm, 86% and 4.0 cm, 84%), respectively. Benzoic (3-morpholinopropyl)carbamothioic thioanhydride has shown at a concentration of 0.01% a high shoot-forming ability, the length of shoots by cutting Spiraea Vanhouttei is on average 3.91 cm, as compared with the control (1.63 cm) and with the preparations Kornevin (2.58 cm) and KN-2 (3.59 cm). Shoot ; Morpholine ; Pharmacophore ; Chemistry ; Benzoic acid ; Biological activity ; Germination ; Acetic acid ; Acylation ; Acetone ; Nuclear chemistry ; Organic chemistry ; Horticulture ; Stereochemistry ; Biochemistry ; Biology Synthesis and biological activity ; Synthesis and Characterization of Heterocyclic Compounds ; Synthesis and Reactivity of Sulfur-Containing Compounds
Authors: Alicja Urbaniak | Chandramohan Bathula | Jyoti Chauhan | Prateek Rai | Joshua Thammathong | Christopher Clark | Billie Heflin | Annick De Loose | Nathan L. Avaritt | Analiz Rodriguez | Alan J. Tackett | Subhabrata Sen | Souvik Banerjee
Source: Chemistry & Biodiversity (article, 2023-11-23)
Field: Chemistry — Organic Chemistry

Synthesis and Anti‐Melanoma Activity of Acryloyl Pyridinone Analogues A major challenge for clinical management of melanoma is the prevention and treatment of metastatic disease. Drug discovery efforts over the last 10 years have resulted in several drugs that improve the prognosis of metastatic melanoma; however, most patients develop early resistance to these treatments. We designed and synthesized, through a concise synthetic strategy, a series of hybrid olefin-pyridinone compounds that consist of structural motifs from tamoxifen and ilicicolin H. These compounds were tested against a human melanoma cell line and patient-derived melanoma cells that had metastasized to the brain. Three compounds 7 b, 7 c, and 7 g demonstrated promising activity (IC50=0.4-4.3 μM). Cell cycle analysis demonstrated that 7 b and 7 c induce cell cycle arrest predominantly in the G1 phase. Both 7 b and 7c significantly inhibited migration of A375 melanoma cells; greater effects were demonstrated by 7 b. Molecular modelling analysis provides insight into a plausible mechanism of action. Melanoma ; Cell cycle ; Cell cycle checkpoint ; Chemistry ; Cancer research ; Drug ; Mechanism of action ; Cell culture ; Pharmacology ; In vitro ; Cell ; Medicine ; Biology ; Biochemistry Synthesis and biological activity ; Synthesis and Biological Evaluation ; Microbial Natural Products and Biosynthesis
Authors: Divya Patel | Kanaparedu P. C. Sekhar | Rati Ranjan Nayak | Sanjit Kanjilal
Source: Journal of Surfactants and Detergents (article, 2023-09-05)
Field: Chemistry — Organic Chemistry

Effect of aromatic ring on surface and self‐assembly properties of synthesized heterocyclic‐based surfactants Abstract Heterocyclic‐based cationic surfactants with dodecyl tail group bridged to the head group either via aromatic ether [3‐(4‐dodecyloxybenzyl)‐1‐methyl‐imidazolium bromide ( Ar‐I ) and 4‐(4‐dodecyloxybenzyl)‐4‐methyl‐morpholinium bromide ( Ar‐M )] or via aliphatic ether [3‐(2‐dodecyloxyethyl)‐1‐methyl imidazolium bromide ( Al‐I ) and 4‐(2‐dodecyloxyethyl)‐4‐methyl morpholinium bromide ( Al‐M )] were synthesized and characterized using different spectral techniques. For the synthesis of Ar‐I and Ar‐M, 4‐hydroxybenzoic acid was esterified initially, followed by O‐alkylation, reduction, bromination and finally quaternization either with 1‐methylimidazole or with 4‐methylmorpholine. For the synthesis of aliphatic analogues (Al‐I and Al‐M), ethylene glycol was initially alkylated, followed by tosylation, bromination and quaternization either with 1‐methylimidazole or with 4‐methylmorpholine. Synthesized surfactants were evaluated for surface and self‐assembly properties. Impact of the presence or absence of phenyl ring bridging the polar head and nonpolar tail of the surfactant and also type of heterocyclic moiety in the head group region on micellization and surface properties such as wetting, foaming and emulsification was studied. Surfactants with the bridged aromatic ether moiety were observed to display lower critical micelle concentration than those with the bridged aliphatic ether moiety irrespective of type of heterocyclic molecule in the head group region. Foam volume and stability of the aromatic ether‐bridged surfactant were observed to be superior to their corresponding aliphatic analogs. Similar trend was observed in stabilizing the emulsion. However, aromatic ether‐bridged surfactant depicted poor wetting ability compared to their aliphatic analog. Aliphatic ether bridged surfactant showed higher aggregation number compared to their aromatic counterparts, but depicted similar micellar core polarity. Chemistry ; Moiety ; Bromide ; Ether ; Pulmonary surfactant ; Cationic polymerization ; Polymer chemistry ; Alkylation ; Micelle ; Critical micelle concentration ; Ethylene glycol ; Organic chemistry ; Aqueous solution Surfactants and Colloidal Systems ; Advanced Polymer Synthesis and Characterization ; Environmental Chemistry and Analysis
Authors: Elham H Algahdali | Sawsan Hassan Mahassni
Source: Journal of Ayurvedic and Herbal Medicine (article, 2023-06-30)
Field: Materials Science — Biomaterials

The aqueous extract of Leptadenia Pyrotechnica Decne enhances the innate immune response and inhibits the acquired immune response, while the aqueous extract of Capparis Cartilaginea Decne does the exact opposite in Healthy Rats Leptadenia pyrotechnica (Forssk.) Decne. (LP) and Capparis cartilaginea Decne. (CC) are plants used in local folk medicine, although there are no published studies on their physiological, hematological, and immune system effects. This study is the first to determine and compare the effects of aqueous LP and CC extracts on body weight parameters, consumptions of feed and water, and the differential complete blood counts in blood samples of healthy Wister albino rats. Six groups of rats (3 rats/group) were orally gavage separately with the aqueous extracts of LP (groups LP1, LP2, and LP3, respectively) and CC (groups CC1, CC2, and CC3, respectively) at concentrations of 30, 100, and 200 mg/kg body weight, while three control rats were gavage with water, daily for two weeks. Body weights were measured daily. The mean total body weights were not significantly different between all groups, between the experimental groups and the control group, and between the equal concentrations of LP and CC groups. The mean total and daily body weight gains and percent relative total body weight gain for the LP3 group were significantly lower compared with the control group. The mean feed and water intakes were highly significantly lower for the LP2, LP3, CC2, and CC3 groups compared with the control group, and for the LP3 group it was significantly lower compared with the CC3 group. The FER for the LP3 group was significantly lower compared with the control group. The mean lymphocyte percent for CC1 was significantly higher and the mean lymphocyte count for LP1 was significantly lower compared with the control. The mean neutrophil percent for LP1 was significantly higher than for CC1 and the mean lymphocyte percents for LP1 and LP2 were significantly lower than for CC1 and CC2. In conclusion, the LP extract enhances the innate immune response and inhibits the acquired immune response, while the CC extract does the exact opposite. Thus, the extract may be used for modulating the immune response. Animal science ; Body weight ; Immune system ; Traditional medicine ; Lymphocyte ; Aqueous extract ; Biology ; Internal medicine ; Chemistry ; Pharmacology ; Medicine ; Immunology Phytochemistry and Bioactive Compounds ; Phytochemicals and Medicinal Plants ; Medicinal Plants and Bioactive Compounds
Authors: Chunyang Lu | K. Mitra | Kiran Mitra | Hanze Meng | Shane T. Rich-New | Fengbin Wang | Dong Si
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2023-11-17)
Field: Materials Science — Materials Chemistry

Protein-Ligand Binding Site Prediction and <i>De Novo</i> Ligand Generation from Cryo-EM Maps Abstract Identification of protein-ligand binding sites is one of the most challenging tasks in drug discovery and design. Recent advances in machine learning community, particularly deep learning, inspired considerable research into deep learning-based methods for protein ligand binding site prediction (PLBP) and have achieved promising results. However one limitation of these methods and models is that they are developed and evaluated using conventional databases consisting of relatively small protein structures determined from X-ray crystallography and NMR with high resolution. When current PLBP methods are directly applied to large protein complexes, they either fail or produce very poor results. Given the increasing popularity of protein structures determined from Cryo-EM maps, which usually capture large protein complexes at relatively low resolution, there is a strong need to apply PLBP methods to Cryo-EM maps. For this purpose, we created a novel database (EMD-Ligand Dataset) consisting of Cryo-EM maps and information about their ligand-binding partners. Our study of several state-of-the-art PLBP methods show that even though they perform reasonably well on conventional databases, they do poorly on the novel EMD-Ligand Dataset, which calls for more research and work to be done by the community. As current methods for determining protein structures experimentally from Cryo-EM maps are time-consuming and expensive, we integrated PLBP methods with DeepTracer, an automatic and fast, de novo Cryo-EM protein structure modeling method, and established an end-to-end system capable of predicting ligand binding sites directly from Cryo-EM maps. Additionally, we leveraged an existing ligand generator to generate drug-like ligands from our predicted ligand-binding pockets and demonstrated its effectiveness. Ligand (biochemistry) ; Computer science ; Artificial intelligence ; Protein ligand ; Resolution (logic) ; Deep learning ; Machine learning ; Pattern recognition (psychology) ; Data mining ; Chemistry Machine Learning in Materials Science ; Protein Structure and Dynamics ; Computational Drug Discovery Methods
Authors: Manoj Kumar Yadav | T. N. Mahadeva Prasad | R. Rathi | Vivek Kumar Kushwaha | Vinay Kumar | Sachin Yadav | Deepak Kumar | Satyam Rai
Source: International Journal of Pharma Professional’s Research (IJPPR) (article, 2023-05-20)
Field: Chemistry — Organic Chemistry

An overview of Quinazolines: Applicability of molecular docking in Cancer therapy Medicinal chemistry is distracted with the elaboration, discovery, confirmation of physical and chemical approaches, and the synthesis in laboratory. Quinazoline derivatives occupy crucial positions in modern medicinal chemistry and possess established application as medicine. Several researches have been accomplished on derivatives of the quinazoline for different many pharmacological activity are reported recently. The most important process molecular docking modification is the preliminary step in the drug designing of novel drugs. The main aim of this review is to quiz or examine recently molecular docking strategies used in medicinal chemistry and in the drug discovery, Investigating the advancement in the field of computer aided drug design, and important role play through the ligand-based method. The drug discovery and the field of CADD is fast flourishing area that has seen various successes. Several giant pharmaceutical industries, in additionally to academia, adopt computer aided drug design and discovery for drug lead discovery. Cancer therapy ; Docking (animal) ; Computational biology ; Computer science ; Cancer ; Medicine ; Internal medicine ; Biology Quinazolinone synthesis and applications ; Synthesis and Characterization of Heterocyclic Compounds ; Synthesis and Biological Evaluation
Authors: Matthew Warner | Tiffany Jeng | Sonya Ayar | Shraddha Sekhar | Delfina Marin | Anthony Engler | Danielle Coverdell | Jackson Ham | Paul A. Kohl
Source: Journal of Applied Polymer Science (article, 2023-03-21)
Field: Chemistry — Organic Chemistry

Reduced graphene oxide catalytically enhances the rate of cyanate ester curing under variable frequency microwave heating Abstract The curing of Lonza Primaset PT‐30 novolac cyanate ester resin and EPON 826 bisphenol‐A diglycidyl ether were investigated using convective thermal heating and variable frequency microwave (VFM) heating. The addition of 1 part per hundred reduced graphene oxide (r‐GO) to PT‐30 novolac cyanate ester increased the VFM cure rate compared to thermal heating. Curing it at 160°C for 240 min with VFM heating resulted in a 55% degree of cure compared to a 26% degree of cure with thermal heating. This observed VFM rate enhancement is due to selective microwave heating of the r‐GO particles in the resin resulting in increased r‐GO catalytic activity toward cyanate ester curing. It is both a thermal and catalytic effect, the latter of which is absent when r‐GO is added to a bisphenol‐A diglycidyl ether resin with o ‐phenylenediamine hardener. Impurities present in the PT‐30 matrix do not appear to contribute to its overall cure kinetics, nor do they participate in the observed VFM rate enhancement. Cyanate ester ; Diglycidyl ether ; Curing (chemistry) ; Cyanate ; Materials science ; Bisphenol A ; Catalysis ; Diphenyl ether ; Oxide ; Thermal stability ; Composite material ; Epoxy ; Polymer chemistry ; Nuclear chemistry ; Chemistry ; Organic chemistry Microwave-Assisted Synthesis and Applications ; Epoxy Resin Curing Processes ; Synthesis and properties of polymers
Authors: Saul Antonio Hernandez Martinez
Source:  (article, 2023-01-01)
Field: Chemistry — Analytical Chemistry

Immobilized laccases on modified magnetic nanoparticles for degradation of common psychiatric drugs used during COVID-19 pandemic Coronavirus disease 2019 (COVID-19) ; Pandemic ; Laccase ; Degradation (telecommunications) ; Magnetic nanoparticles ; Nanoparticle ; 2019-20 coronavirus outbreak ; Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ; Virology ; Materials science ; Medicine ; Chemistry ; Nanotechnology ; Computer science ; Internal medicine ; Organic chemistry ; Infectious disease (medical specialty) Dye analysis and toxicity
Authors: Kiruthigadevi Kamaraj | Pierre H. Dixneuf | Joost N. H. Reek | Charles Beromeo Bheeter
Source: ChemRxiv (preprint, 2023-11-29)
Field: Chemistry — Inorganic Chemistry

"Liq. Hydrogen carrier and C1 source – Methanol” mediated Selective N-Methylation of Urea via Transfer Hydrogenation catalyzed by Pd/C We report the catalytic transfer hydrogenation of urea derivatives using green hydrogen from methanol, which is the most ambitious effort in this hydrogenation world. On enlarging this methodology, selective N-methylated amines achieved from urea which are widely featured in drugs, natural products, paints etc. Moreover, this methodology making a sustain-able alternative pathway for the synthesis of selective methylated derivative from CO2 derived compound. The key to the success of this transformation is the use of a commercially available Pd/C heterogenous catalyst and Methanol which act as both H2 and C1 sources. In addition, several control experiments with the plausible intermediates were performed to analyze this novel pathway. This transformation proceeds in an environmentally friendly greener protocol and high at-om-economy. Catalysis ; Methanol ; Urea ; Chemistry ; Transfer hydrogenation ; Environmentally friendly ; Methylation ; Hydrogen ; Combinatorial chemistry ; Transformation (genetics) ; Derivative (finance) ; Organic chemistry ; Business ; Biochemistry ; Gene ; Biology Asymmetric Hydrogenation and Catalysis ; Carbon dioxide utilization in catalysis ; Ammonia Synthesis and Nitrogen Reduction
Authors: Qi Zheng
Source: Highlights in Science Engineering and Technology (article, 2023-08-29)
Field: Materials Science — Biomaterials

Application of nanodiamond in the diagnosis and treatment of neurological diseases The blood-brain barrier has long been a barrier to the treatment of neurological diseases in the brain. It protects brain tissues from damage while limiting the access of drugs to the brain for drug delivery, so nanocarriers with smaller particle size are chosen to break the blood-brain barrier. This review summarizes the structural properties of nanodiamond, the interaction mechanism between nanodiamond and blood-brain barrier, and the application of nanodiamond as a carrier in the diagnosis and treatment of neurological diseases, which provides the theoretical basis for the subsequent diagnosis and treatment of neurological diseases. Nanodiamond ; Blood–brain barrier ; Nanocarriers ; Limiting ; Medicine ; Drug ; Intensive care medicine ; Neuroscience ; Pharmacology ; Materials science ; Internal medicine ; Central nervous system ; Biology Nanoparticle-Based Drug Delivery ; Nanoplatforms for cancer theranostics ; Intracranial Aneurysms: Treatment and Complications