NO2 Group Research Articles

Utilization of Recycled Egg Carton Pulp for Nitrocellulose as an Accelerant in Briquette Production.

Nitrocellulose (NC) is a conservative material that is used in a variety of applications, such as coating agents, biodegradable plastics, and propellant main charge. Nitrocellulose raw materials are easily obtained from lignocellulose sources, most notably cotton and wood pulp. The egg carton, a recycled paper waste designed for packaging and transporting eggs, is used in this study to make nitrocellulose in pulp form. The effects of different nitration durations (40, 50, and 60 min) from egg carton pulp bleached with various KOH concentrations (0.6 M, 1.0 M, and 1.5 M) on NC properties were evaluated. The accelerant properties of the NC of nitration time in 50 min were studied in a rice husk charcoal briquette. Rice husk charcoal briquettes are made in various ratios with nitrocellulose as an accelerant (97:3, 96:4, and 95:5). The NC was characterized using Fourier transform infrared (IR) spectroscopy and thermogravimetric (TG) analysis. 1.0 M of bleached egg carton pulp has the highest cellulose content (86.94%) with the presence of crystalline structure of cellulose at peak 1430 cm-1 after the bleaching process. Meanwhile, different nitration times revealed that 50 min had the highest nitrogen content (7.97%) with a 1.23 degree of substitution (DS) value. Based on its TG analysis, NC 50 has met the requirements for use as an accelerant for briquettes, with an onset temperature of 91.60 °C and a weight loss of 62.60%. Infrared at peak 1640 cm-1 confirmed the presence of NO2 groups in nitrocellulose successfully formed by nitration. After the addition of nitrocellulose, the calorific value of the briquette increased from 13.54% to 15.47%. Fixed carbon and volatile matter showed the same pattern. The combustion of nitrocellulose-briquette has also been demonstrated by Td10% of degradation, which degraded between 310 and 345 °C.

Systematically investigation on the spectral, antioxidant and antibacterial properties of fragrant methyl benzoate esters containing electron withdrawing and electron releasing groups

In this study, the effects of electron-withdrawing or electron-releasing groups in methyl benzoate esters, which are widely used in the fragrance industry, on the antioxidant and antibacterial activities of the compounds were investigated. Firstly, methyl benzoates with electron-withdrawing (NO2 and Cl groups) or electron-donating groups (CH3 and OCH3 groups) in the para position, which are commercial compounds, were synthesized, and extensively studied in terms of reaction conditions, and spectral data in their instrumental analysis methods. Then, the synthesized compounds were evaluated for their antioxidant, antibacterial, and cytotoxic activities. Among them, methyl 4-nitrobenzoate exhibited the highest inhibition against Staphylococcus aureus and Pseudomonas aeruginosa. Methyl 4-methoxybenzoate was selected for cytotoxicity evaluation due to its high antioxidant activity, and while the results indicated a dose-dependent decrease in cell viability, lower concentrations may still be considered for cosmetic applications. These findings suggest that antioxidant activity and cytotoxic activity are directly related to the electron density of the molecule. Therefore, this very up-to-date research covers many implications for organic chemistry, medicinal chemistry, biotechnology, and microbiology. Therefore, the results obtained may have great potential to be applied in the cosmetic industry and could be used as exceptionally useful information on alternative raw material selection for researchers in the fragrance industry. These results also suggest that methyl benzoates have potential as lead compounds for the development of novel antioxidant, antibacterial, and cytotoxic agents, but further studies are needed to fully explore their applications in various fields.

Naphthalene-Based Polymers as Catalytic Supports for Suzuki Cross-Coupling.

In this work, for the first time, naphthalene (NA)-based polymers were synthesized by one-stage Friedel-Crafts crosslinking. The influence of NA functionalization by -OH, -SO3H, and -NO2 groups on the polymers' porosity and distribution of the catalytically active phase (Pd) was studied. Synthesized catalytic systems containing 1 wt.% of Pd either in the form of Pd(II) species or Pd(0) nanoparticles supported on NA-based polymers were tested in a model reaction of Suzuki cross-coupling between 4-bromoanisole and phenylboronic acid under mild reaction conditions (60 °C, ethanol-water mixture as a solvent). These novel catalysts demonstrated high efficiency with more than 95% of 4-bromoanisole conversion and high selectivity (>97%) for the target 4-methoxybiphenyl.

Synthesis of Analogs to A-Type Proanthocyanidin Natural Products with Enhanced Antimicrobial Properties against Foodborne Microorganisms.

Developing new types of effective antimicrobial compounds derived from natural products is of interest for the food industry. Some analogs to A-type proanthocyanidins have shown promising antimicrobial and antibiofilm activities against foodborne bacteria. We report herein the synthesis of seven additional analogs with NO2 group at A-ring and their abilities for inhibiting the growth and the biofilm formation by twenty-one foodborne bacteria. Among them, analog 4 (one OH at B-ring; two OHs at D-ring) showed the highest antimicrobial activity. The best results with these new analogs were obtained in terms of their antibiofilm activities: analog 1 (two OHs at B-ring; one OH at D-ring) inhibited at least 75% of biofilm formation by six strains at all of the concentrations tested, analog 2 (two OHs at B-ring; two OHs at D-ring; one CH3 at C-ring) also showed antibiofilm activity on thirteen of the bacteria tested, and analog 5 (one OH at B-ring; one OH at D-ring) was able to disrupt preformed biofilms in eleven strains. The description of new and more active analogs of natural compounds and the elucidation of their structure-activity relationships may contribute to the active development of new food packaging for preventing biofilm formation and lengthening the food shelf life.

Endoplasmic reticulum-targeted fluorescent probes for metal-free tracking of carbon monoxide in living cells

Endoplasmic Reticulum (ER) targetable fluorescent probes, ER-NapNO2 and ER-NapAllyl, have been designed and synthesized based on 1,8-naphthalimide fluorophore, for the selective and targeted detection of carbon monoxide (CO) in aqueous buffer medium of pH 7.4 at 37 °C. ER-targetable moiety, methyl sulfonamide unit, was attached with the one part with the fluorophore and another part was connected with CO reactive zone i.e. 4-nitrobenzyle and allyl group. Very weak fluorescence signals were observed with both the probes due to the possible PET process operating from naphthalimide moiety to electron withdrawing units i.e. -NO2 and allyl group. Interestingly, both of the probes exhibited their selective detection behavior towards CO in aqueous reaction buffer in absence of any metal ions e.g., palladium, rhodium, iron etc. The possible expulsion of highly fluorescent naphthalimide-derivative was identified from the reaction mixture during the reaction of both the probes and CO. The detection technique is found to highly selective towards CO over various reactive oxygen, nitrogen, sulfur, and other biological species with low detection limit, 0.080 µM and 0.161 µM of ER-NapNO2 and ER-NapAllyl respectively. Theoretical study using time dependent density functional theory (TDDFT) optimized the end-products formed after the reaction with CO and probes which excellently corroborate with the experimental observation. Also, the sensing reactions are exothermic with computed free energy changes for ER-NapNO2 and ER-NapAllyl are − 158.74 kcal/mol and − 28.51 kcal/mol respectively. Cellular confocal fluorescence microscopic experiments showed that these probes are also efficient to detect CO in ER specific regions in living cells.

Synthetic transformation of 6-Fluoroimidazo[1,2-a]Pyridine-3-carbaldehyde into 6-Fluoroimidazo[1,2-a]Pyridine-Oxazole Derivatives: In vitro urease inhibition and in silico study

PurposeUlcer is a serious disease that is caused due to different bacteria and over usage of various NSAIDs which caused to reduce the defensive system of stomach. Therefore, some novel series are needed to overcome these issues. MethodsOxazole-based imidazopyridine scaffolds (4a-p) were designed and synthesized by two step reaction protocol and then subjected to urease inhibition profile (in vitro). All the newly afforded analogs (4a-p) were found potent and demonstrated moderate to significant inhibition profile. ResultsParticularly, the analogs 4i (IC50 = 5.68 ± 1.66 μM), 4o (IC50 = 7.11 ± 1.24 μM), 4 g (IC50 = 9.41 ± 1.19 μM) and 4 h (IC50 = 10.45 ± 2.57 μM) were identified to be more potent than standard thiourea drug (IC50 = 21.37 ± 1.76 μM). Additionally, the variety of spectroscopic tools such as 1H NMR, 13C NMR and HREI-MS analysis were employed to confirm the precise structures of all the newly afforded analogs. DiscussionThe structure–activity relationship (SAR) studies showed that analogs possess the substitution either capable of furnishing strong HB like –OH or had strong EW nature such as -CF3 & –NO2 groups displayed superior inhibitory potentials than the standard thiourea drug. A good PLI (protein–ligand interaction) profile was shown by most active analogs when subjected to molecular study against corresponding target with key significant interactions such as pi-pi stacking, pi-pi T shaped and hydrogen bonding.

Catalytically enhanced direct degradation of nitro-based antibacterial agents using dielectric barrier discharge cold atmospheric pressure plasma and rhenium nanoparticles

The common utilization of antimicrobial agents in medicine and veterinary creates serious problems with multidrug resistance spreading among pathogens. Bearing this in mind, wastewaters have to be completely purified from antimicrobial agents. In this context, a dielectric barrier discharge cold atmospheric pressure plasma (DBD-CAPP) system was used in the present study as a multifunctional tool for the deactivation of nitro-based pharmacuticals such as furazolidone (FRz) and chloramphenicol (ChRP) in solutions. A direct approach was applied to this by treating solutions of the studied drugs by DBD-CAPP in the presence of the ReO4− ions. It was found that Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS), generated in the DBD-CAPP-treated liquid, played a dual role in the process. On the one hand, ROS and RNS led to the direct degradation of FRz and ChRP, and on the other hand, they enabled the production of Re nanoparticles (ReNPs). The produced in this manner ReNPs consisted of catalytically active Re+4, Re+6, and Re+7 species which allowed the reduction of –NO2 groups contained in the FRz and ChRP. Unlike the DBD-CAPP, the catalytically enhanced DBD-CAPP led to almost FRz and ChRP removals from studied solutions. The catalytic boost was particularly highlighted when catalyst/DBD-CAPP was operated in the synthetic waste matrix. Re-active sites in this scenario led to the facilitated deactivation of antibiotics, achieving significantly higher FRz and ChRP removals than DBD-CAPP on its own.

Molecular properties and In silico bioactivity evaluation of (4-fluorophenyl)[5)-3-phen-(4-nitrophenyl yl-4,5-dihydro-1H-pyrazol-1-yl]methanone derivatives: DFT and molecular docking approaches

ObjectivesMolecular structures, spectroscopic properties, charge distributions, frontier orbital energies, nonlinear optical (NLO) properties and molecular docking simulations were analyzed to examine the bio-usefulness of a series of (4-fluorophenyl)[5-(4-nitrophenyl)-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl]methanone derivatives. MethodsThe compounds were studied through computational methods. Equilibrium optimization of the compounds was performed at the B3LYP/6-31G(d,p) level of theory, and geometric parameters, frequency vibration, UV–vis spectroscopy and reactivity properties were predicted on the basis of density functional theory (DFT) calculations. ResultsThe energy gap (ΔEg), electron donating/accepting power (ω−/ω+) and electron density response toward electrophiles/nucleophiles calculated for M1 and M2 revealed the importance of substituent positioning on compound chemical behavior. In addition, ω−/ω+ and ΔEn/ΔEe indicated that M6 is more electrophilic because of the presence of two NO2 groups, which enhanced its NLO properties. The hyperpolarizability (β0) of the compounds ranged from 5.21 × 10−30 to 7.26 × 10−30 esu and was greater than that of urea; thus, M1–M6 were considered possible candidates for NLO applications. Docking simulation was also performed on the studied compounds and targets (PDB ID: 5ADH and 1RO6), and the calculated binding affinity and non-bonding interactions are reported. ConclusionThe calculated ω− and ω+ indicated the electrophilic nature of the compounds; M6, a compound with two NO2 groups, showed enhanced effects. Molecular electrostatic potential (MEP) analysis indicated that amide and nitro groups on the compounds were centers of electrophilic attacks. The magnitude of the molecular hyperpolarizability suggested that the entire compound had good NLO properties and therefore could be explored as a candidate NLO material. The docking results indicated that these compounds have excellent antioxidant and anti-inflammatory properties.

Nematic Phase of Polar Unsymmetrical Bent-Core Molecules.

In liquid crystalline systems, the presence of polar groups at lateral or terminal positions is fundamentally and technologically important. Bent-core nematics composed of polar molecules with short rigid cores usually exhibit highly disordered mesomorphism with some ordered clusters that favourably nucleate within. Herein, we have systematically designed and synthesized two new series of highly polar bent-core compounds comprised of two unsymmetrical wings, highly electronegative -CN and -NO2 groups at one end, and flexible alkyl chains at the other end. All the compounds showed a wide range of nematic phases composed of cybotactic clusters of smectic-type (Ncyb ). The birefringent microscopic textures of the nematic phase were accompanied by dark regions. Further, the cybotactic clustering in the nematic phase was characterized via temperature-dependent XRD studies and dielectric spectroscopy. Besides, the birefringence measurements demonstrated the ordering of the molecules in the cybotactic clusters upon lowering the temperature. DFT calculations illustrated the favourable antiparallel arrangement of these polar bent-core molecules as it minimizes the large net dipole moment of the system.

Enhancement of Halogen Bond Strength by Intramolecular H-Bonds.

Quantum calculations study the potential of an intramolecular H-bond between the halogen atom (X) of a halobenzene and a substituent placed ortho to it, to amplify the ability of X to engage in a halogen bond (XB) with a Lewis base. H-bonding substituents NH2, CH2CH2OH, CH2OH, OH, and COOH were added to halobenzenes (X = Cl, Br, I). The amino group had little effect, but those containing OH increased the CX···N XB energy to a NH3 nucleophile by about 0.5 kcal/mol; the increment associated with COOH is larger, nearly 2 kcal/mol. These energy increments were approximately doubled if two such H-bonding substituents are present. Combining a pair of ortho COOH groups with an electron-withdrawing NO2 group in the para position has a particularly large effect, raising the XB energy by about 4 kcal/mol, which can amount to as much as a 4-fold magnification.

Performance of first derivative UV/Visible spectra for kinetic and isothermal study of simultaneous adsorption of o-nitrophenol and p-nitrophenol onto Al2O3 and HDTMA+/Al2O3 composite

Adsorption of ortho-nitrophenol (o-NP) and para-nitrophenol (p-NP) from single and binary aqueous solutions onto Al2O3 and its composite, hexadecyltrimethylammonium bromide (HDTMA+/Al2O3), were studied in batch experiments at T = 25 °C and at pH = 6. In order to overcome the problem of overlapping absorbance bands of o-NP and p-NP, a first-order derivative UV/Visible spectrophotometric method (FODS) was applied for the simultaneous determination of each adsorbate in their residual binary solutions. Experimental adsorption data of o-NP and p-NP in single and binary solutions were found to follow adequately a pseudo-second order kinetic model. Based on the values of R2, χ2 and Δq(%), the Freundlich model showed better fitting to the equilibrium isotherms data, followed by Redlich-Peterson and Langmuir models, suggesting the existence of heterogeneous sites on the adsorbent surfaces. In all the experiments, HDTMA+/Al2O3 showed a superior adsorption capacity for o-NP and p-NP than Al2O3, and the adsorption of o-NP on both adsorbents was favored. However, adsorption capacity of each isomer in binary mixtures were found lower than that in a single component, reflecting a competitive adsorption mechanism, involving mainly the hydrogen bonding between NO2 and OH groups of o-NP/p-NP and the functional groups of the adsorbents, which affected their selectivity.

Boosting Activity and Selectivity of UiO‐66 through Acidity/Alkalinity Functionalization in Dimethyl Carbonate Catalysis (Small 18/2023)

Pd-NO2-UiO-66 for DMC Catalysis In article number 2208238, Ye-Yan Qin, Yuan-Gen Yao, and co-workers first introduce acidity/alkalinity functionalized metal–organic frameworks (MOFs) into dimethyl carbonate (DMC) catalysis, and the Lewis acidic Pd-NO2-UiO-66 exhibits excellent catalytic behavior. In addition to affecting the interaction of Pd(II) and support, the -NO2 group has a dominant role in the chemisorption of methyl nitrite (MN) and CO for generating DMC.

Regulating Chemistry Composition on a Crystal Surface by Introducing a Cation Trapping Agent: A Novel Strategy to Tune Moisture Sensitivity of Crystals.

The crystal moisture sensitivity can be tuned by the chemical composition on the crystal surface. Ammonium dinitramide (ADN) crystal is a promising oxidizer for solid propellants. However, its strong moisture sensitivity greatly limits its practical applications. Here, we report a novel strategy to reduce moisture sensitivity by trapping ammonium cations with montmorillonite (MMT) to modulate the chemistry composition on the ADN crystal surface. An extraordinary phenomenon can be found: the crystal surface of the recrystallized ADN with 1% MMT (ADN-1% MMT) is rearranged with more low-surface-energy -NO2 groups (65.84%) and less high-surface-energy NH4+ groups (4.8%). In addition, ADN-1% MMT presents a more homogeneous low surface energy feature with a narrower surface energy distribution. As a result, ADN-1% MMT exhibits a noticeably lower hygroscopicity at 20 °C and 60% RH, which is accordant with the simulated hygroscopicity based on XRD and moisture sensitivity prediction based on surface energy. This study brings out a novel modification idea to adjust crystal moisture sensitivity by tuning the chemistry composition on the crystal surface based on trapping cations.

Design and computational studies on energetic compounds composing bridged bis triazolo-triazine framework

Density functional theory was used to design a new series of bridged (directly connected, –CH = CH–, –CH2–, –CH2–CH2–, –O–, –NH–, –NH–NH–, –N=N–) energetic compounds based on bis[1,2,4] triazolo[4,3-b:4′,3′-d][1,2,4]triazine (bis triazolo-triazine) backbone with explosophoric functionalities (–NO2, –NHNO2, and –NH2 groups). Using the predicted densities and heats of formation in Kamlet-Jacobs equations, detonation performance was assessed, which specify that the –NO2 group is a suitable explosophore for enhancing performance. Comparing the influence of different linkages on detonation properties it is observed that –O–, –NH–, and –N=N– linkages are more beneficial for enhancing performance. The bond dissociation energy (BDE), heat of detonation (Q), balance parameter (ν), and impact sensitivity (h50) values were utilized to determine stability and sensitivity. Some designed bis triazolo-triazine molecules have high densities (>1.85 g/cm3) and good detonation performance (VOD > 8.40 km/s and DP > 32 GPa), may be considered as the potential energetic material candidates.

Mesomeric Acceleration Counters Slow Initiation of Ruthenium-CAAC Catalysts for Olefin Metathesis (CAAC = Cyclic (Alkyl)(Amino) Carbene).

Ruthenium catalysts bearing cyclic (alkyl)(amino)carbene (CAAC) ligands can attain very high productivities in olefin metathesis, owing to their resistance to unimolecular decomposition. Because the propagating methylidene species RuCl2(CAAC)(=CH2) is extremely susceptible to bimolecular decomposition, however, turnover numbers in the metathesis of terminal olefins are highly sensitive to catalyst concentration, and hence loadings. Understanding how, why, and how rapidly the CAAC complexes partition between the precatalyst and the active species is thus critical. Examined in a dual experimental-computational study are the rates and basis of initiation for phosphine-free catalysts containing the leading CAAC ligand C1 Ph , in which a CMePh group α to the carbene carbon helps retard degradation. The Hoveyda-class complex HC1 Ph (RuCl2(L)(=CHAr), where L = C1 Ph , Ar = C6H3-2-O i Pr-5-R; R = H) is compared with its nitro-Grela analogue (nG-C1 Ph ; R = NO2) and the classic Hoveyda catalyst HII (L = H2IMes; R = H). t-Butyl vinyl ether (tBuVE) was employed as substrate, to probe the reactivity of these catalysts toward olefins of realistic bulk. Initiation is ca. 100× slower for HC1 Ph than HII in C6D6, or 44× slower in CDCl3. The rate-limiting step for the CAAC catalyst is cycloaddition; for HII, it is tBuVE binding. Initiation is 10-13× faster for nG-C1 Ph than HC1 Ph in either solvent. DFT analysis reveals that this rate acceleration originates in an overlooked role of the nitro group. Rather than weakening the Ru-ether bond, as widely presumed, the NO2 group accelerates the ensuing, rate-limiting cycloaddition step. Faster reaction is caused by long-range mesomeric effects that modulate key bond orders and Ru-ligand distances, and thereby reduce the trans effect between the carbene and the trans-bound alkene in the transition state for cycloaddition. Mesomeric acceleration may plausibly be introduced via any of the ligands present, and hence offers a powerful, tunable control element for catalyst design.

The substituent effect on CW laser beam self-action manifestation under UV irradiation of azo-azomethine PMMA composites thin films

We report synthesis and study of E→Z→E photoswitching transformations of methyl-substituted azo-aldehyde and six novel corresponding azo-azomethines containing electron withdrawing/donating substituents in para-position to – CHN– bond, being analyzed by UV–Vis and 1H NMR spectroscopy techniques. Impact of donor/acceptor substituent nature on isomerization kinetics was studied in THF solutions by light activation at 390 nm. We obtained high optical quality of PMMA thin films doped with mentioned dyes. It was characterized with both angularly resolved optical elastic scattering data and nonlinear refractive/absorptive optical responses analysis via CW laser beam self-action effects manifestation at wavelength 532 nm. Pronounced self-focusing effect contribution was shown for electron donating substituents (-CH3, -OCH3) and self-defocusing one for electron withdrawing -NO2 group. UV irradiation at 254 nm provides switching from self-defocusing to self-focusing mode of -NO2 substituted dye-doped film with refractive nonlinear optical response efficiency Re(χ(3)) ≈10−2 esu on background of moderate photoinduced absorption effects manifestation.

The pH dependence of photochemical reactions between methoxyphenols with Fe(III)-oxalates

The changes in optical properties and chemical compositions of four methoxyphenols, including guaiacol (GU), vanillin (VA), 4-nitroguaiacol (NGU) and 5-nitrovanillin (NVA) were investigated during the photochemical reaction with Fe(III)-oxalates. The reaction pathways of methoxyphenols with Fe(III)-oxalates were varied with solution pH. Four methoxyphenols were significantly decomposed by ·OH produced from Fe(III)-oxalates under irradiation at a solution pH of 3, followed by the formation of phenols, ketones and ethers. The degradation rate of methoxyphenols was closely correlated to electron-withdrawing groups on the benzene ring, such as NO2 and CHO groups. Under the neutral condition, the absorbance of methoxyphenols varied or remained unchanged, depending on the pKa values of methoxyphenols. The changes in the light absorption of VA and NGU solutions were contributed to the deprotonation of OH group in the presence of dissolved O2.

Effect of NO2 Aging on the Surface Structure and Thermal Stability of Silicone Rubber with Varying Al(OH)3 Contents

In this study, silicone rubber (SiR) with 0, 90, and 180 parts of aluminum hydroxide (Al(OH)3, ATH) contents prepared in the laboratory was treated in a certain concentration of NO2 for 0, 12, 24, and 36 h. Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and thermogravimetry (TG) were used to study the changes in the surface structure and thermal stability of SiR, as well as the influence of Al(OH)3 on the properties of SiR. According to AFM, the root-mean-square roughness of ATH-90 SiR was 192 nm, which was 2.7 times of ATH-0 SiR. With the incorporation of ATH, the surface of SiR became more susceptible to corrosion by NO2. According to FT-IR and XPS, with the increase in aging time, the side chain Si-CH3 of polydimethylsiloxane (PDMS) was oxidized gradually and a few of nitroso -NO2 groups were formed. According to TG, the incorporation of ATH caused the maximum decomposition rate temperature of PDMS to advance from 458.65 °C to 449.37 and 449.26 °C, which shows that the thermal stability of SiR degraded by adding ATH. After NO2 aging, a new decomposition stage appeared between 75 and 220 °C (stage Ⅰ), and this decomposition trend was similar to aluminum nitrate, which was proven to reduce the thermal stability of PDMS. The effects of NO2 on the surface structure and thermal stability of different ATH contents of silicone rubber were preliminarily clarified by a variety of characterization methods, which provided ideas for the development of silicone rubber resistant to NO2 aging.

Parsing structural fragments of thiazolidin-4-one based α-amylase inhibitors: A combined approach employing in vitro colorimetric screening and GA-MLR based QSAR modelling supported by molecular docking, molecular dynamics simulation and ADMET studies

α-Amylase (EC.3.2.1.1) is a ubiquitous digestive endoamylase. The abrupt rise in blood glucose levels due to the hydrolysis of carbohydrates by α-amylase at a faster rate is one of the main reasons for type 2 diabetes. The inhibitors prevent the action of digestive enzymes, slowing the digestion of carbs and eventually assisting in the management of postprandial hyperglycemia. In the course of developing α-amylase inhibitors, we have screened 2-aryliminothiazolidin-4-one based analogs for their in vitro α-amylase inhibitory potential and employed various in silico approaches for the detailed exploration of the bioactivity. The DNSA bioassay revealed that compounds 5c, 5e, 5h, 5j, 5m, 5o and 5t were more potent than the reference drug (IC60 value = 22.94 ± 0.24 μg mL−1). The derivative 5o with –NO2 group at both the rings was the most potent analog with an IC60 value of 19.67 ± 0.20 μg mL−1 whereas derivative 5a with unsubstituted aromatic rings showed poor inhibitory potential with an IC60 value of 33.40 ± 0.15 μg mL−1. The reliable QSAR models were developed using the QSARINS software. The high value of R2ext = 0.9632 for model IM-9 showed that the built model can be applied to predict the α-amylase inhibitory activity of the untested molecules. A consensus modelling approach was also employed to test the reliability and robustness of the developed QSAR models. Molecular docking and molecular dynamics were employed to validate the bioassay results by studying the conformational changes and interaction mechanisms. A step further, these compounds also exhibited good ADMET characteristics and bioavailability when tested for in silico pharmacokinetics prediction parameters.

Modulating the Roaming Dynamics for the NO Release in ortho-Nitrobenzenes

The dynamics of NO release upon photodissociation of nitroaromatic compounds is dependent on the nature of the interaction between the NO2 group and substituent in the ortho position. A bimodal (slow and fast) translational energy distribution of the NO photofragment indicates the presence of two distinct NO elimination channels. The slow-to-fast branching ratio for the NO release is regulated by the hydrogen bonding ability of the ortho substituent and follows the order [OH > NH2 > CH3 > OCH3], indicating that the intramolecular hydrogen bonding plays a pivotal role in NO release dynamics. Further, the topology of the triplet state potential energy surface acts as a doorway to the dissociation pathway switching between the roaming and nonroaming mechanisms, with hydrogen bonding substituents (OH and NH2) favoring the roaming mechanism.