Benzenedicarboxylic Acid Research Articles

A highly sensitive and fully flexible Fe-Co metal-organic framework hydrogel based gas sensor for ppb level detection of acetone

Most nanomaterials based gas sensors are established on rigid substrates which require operation at elevated temperature and involve long recovery times, thus, limiting their practical applications. Addressing these issues, we demonstrate a fully flexible Fe/Co metal organic framework hydrogel (Fe/Co MOF HG) based gas sensor that detects ultra-low concentrations of acetone at room temperature. This hydrogel is synthesized using optimized concentration (3:1 M ratio) of Co:Fe with benzene dicarboxylic acid (BDC) in Fe/Co MOF via solvothermal method followed by lyophilization. Detailed morphological evaluation reveals 3-dimentional porous structure with multiple voids which largely enhances the specific surface area. Upon exposure to acetone, the Fe/Co MOF HG with Cu metal contacts based sensor exhibits a sensing response (S%) of 12.28 % to 500 ppb of acetone with a wide dynamic range of 200 ppb to 4 ppm. This remarkable sensitivity can be attributed to the abundance of water-adsorbed oxygen (Oc% = 24.58 %) in hydrogel as confirmed by XPS technique, which helps in the increase of the adsorption of a large proportion of acetone molecules on the surface of hydrogel. The limit of detection (LOD = 3σ/s) is found to be 103 ppb which is significantly lower than the other reported MOF-based acetone sensors. Further, the sensor demonstrates excellent selectivity against other common VOCs such as ammonia, benzene, toluene, and formaldehyde. Finally, the sensor’s outstanding stability (upto one-month), mechanical robustness when subjected to 230 cycles of bending and resilience to changes in humidity opens up new possibilities for the use of MOF-based hydrogels as gas sensors in several wearable device domains, such as health care and environmental monitoring.

Enhancing the electrochemical performance of supercapacitor electrodes using as-synthesized CuO and MOF-derived CuO nanostructures

Metal organic framework (MOF) have gained considerable attention in the field of energy storage and supercapacitors applications. Herein, we synthesized copper oxide (CuO) through the precipitation method and concurrently derived from the solvothermal prepared copper-benzene dicarboxylate (Cu-BDC) by calcination. The integration of MOF-derived nanostructures with traditional CuO to form a hybrid electrode material, has not been extensively explored. The synthesized materials were characterized using XRD, FTIR, XPS, BET and morphological analysis was conducted using SEM, affirming the composite's nature. Electrochemical impedance spectroscopy, galvanostatic charge-discharge, and cyclic voltammetry were used to evaluate the electrochemical properties of electrode material. With a specific capacitance of 691 F g-1 for CuO obtained from Cu-BDC (benzene dicarboxylic acid) and 236 Fg-1 for CuO via the precipitation method, measured at a scan rate of 5 mV/s in 6 M KOH was found to be the optimal performance solution for the electrode material. The mesoporous structures are crucial for their absorption ability and improved ion transport, resulting in optimized electrochemical performance. Finally, we demonstrate significant improvements in specific capacitance and cycling stability compared to pure CuO-based electrodes, highlighting the potential of this composite structure for advanced supercapacitor applications.

Enhanced Local Ion Transport in High-Performance Anion Exchange Membrane Water Electrolyzers Via Quaternary Ammonium-Functionalized Metal-Organic Framework Electrocatalysts

Anion-exchange membrane water electrolyzers (AEMWEs) present a multitude of advantages, particularly in the utilization of non-platinum group (non-PGM) catalysts. While diverse catalysts have demonstrated notable electrocatalytic activity in alkaline conditions, the integration of the ionomer with the electrocatalyst at the active catalyst layer is crucial for enhancing overall AEMWE performance in practical device demonstrations by improving mass transport. However, the intrinsic instability of polymeric ionomers, leading to physical detachments or alkaline (chemical) degradation, poses a challenge that can potentially diminish performance. In this study, drawing inspiration from the aforementioned ionomer chemistry, we introduce non-PGM NiFe-based metal-organic frameworks (MOFs) incorporating quaternary ammonium (QA) cation moieties covalently functionalized to benzenedicarboxylic acid (BDC) ligands as promising electrocatalysts for the oxygen evolution reaction (OER) in alkaline environments. Three specifically designed functional groups with varying ion exchange capacities (IEC) and alkaline stability—trimethylamine (TMA), N-methylpyrrolidine (C4N), and N-methylpiperidine (C5N)—were directly tethered to BDC ligands. The alkaline OER activity of Ni2Fe1-QA-MOF was meticulously assessed using rotating disk electrodes and AEMWE devices. These directly tethered QA groups markedly facilitated improved ionic transport of OH- ions at the catalyst/electrolyte interfaces compared to BDC ligands, ultimately leading to a significant enhancement in half-cell activity and AEMWE performance. In-situ IR/RAMAN spectroscopy revealed that QA moieties highly promoted local ionic transport at the interfaces, as evidenced by characteristic peaks indicating a robust interaction between QA and OH- ions. Unexpectedly, QA moieties not only contributed to ionic transport in local environments but also induced oxidation states of Ni metal sites, while Fe sites exhibited no changes during the applied potential in the OER region, as comprehensively revealed by synchrotron X-ray absorption spectroscopy (XAS). In comparison with conventional NiFe layered double hydroxide (LDH) structures, we posit that the substantial structural transformation of Ni moieties can be attributed to an increased degree of M-O bond interaction, enhanced by the local interaction between QA and OH- ions. Density functional theory (DFT) calculations also validate the balanced adsorption of OER intermediates on QA-MOFs. Finally, QA-NiFe-MOF was directly synthesized on a porous transport layer (PTL), and its AEMWE performance was evaluated without the use of any ionomer. At 1.0 M KOH, C4N, C5N, and TMA-based NiFe MOFs exhibited current densities of 9.35 A/cm2, 9.11 A/cm2, and 7.6 A/cm2, respectively. These current densities surpassed those of bare BDC-NiFe MOF and commercial IrO2 anode catalysts, which exhibited only 7.39 A/cm2 and 6.4 A/cm2, respectively. Consequently, we emphasize that the facilitation of local ionic transport could yield remarkable AEMWE performance, even in the absence of conventional polymeric ionomers.

Phytochemical Composition of Urtica dioica Essential Oil with Antioxidant and Anti-inflammatory Properties: In Vitro and In Vivo Studies

Urtica dioica (Urticaceae) has outstanding medicinal and pharmacological properties. This investigation was aimed to assess the chemical composition, the total polyphenol and flavonoid content, antioxidant, anti-proliferative, and anti-inflammatory effects of Urtica dioica essential oil (UDEO) GC/MS analysis was performed to assess the chemical composition, standard antioxidative test, the DPPH assay, the reducing power assay, as well as the anti-proliferative capacities of UDEO against HeLa cell lines using the MTT test. In addition, the anti-inflammatory activities of UDEO were evaluated using paw thickness measurements in rats with carrageenan-induced paw edema and pathologic evaluation of inflammation in paw sections. GC/MS analysis revealed benzene dicarboxylic acid (14.69%), β-linalool (9.79%), phytol (9.52%), menthol (6.65%), borneol (6.45%), 3-Eicosene (E) (6.10%), 1-8 cineole (5.60%) and camphor (5.36%) as the major components of UDEO. In vitro results showed that UDEO contained 191 ± 2.04 mg GAE/g of polyphenols and 83.59 ± 4.7 mg CE/g of flavonoids. In addition, the UDEO showed a radical scavenging activity with IC50 = 0.14 ± 0.003 mg/mL and a ferric reducing antioxidant power (FRAP) (optical density = 0.556). A side from the UDEO's antioxidant properties, our findings revealed a reduction in ROS generation in the HeLa cell line. Furthermore, the anti-proliferative activity of UDEO is accompanied by a cytotoxicity effect (IC50 at 3.20 μg ml-1). Data from inflammation models revealed that UDEO has an anti-inflammatory effect. The pretreatment with UDEO or Indomethacin (Ind) reduced significantly the volume of edema induced by Carr, the level of C-reactive protein (CRP), the reactive thiobarbituric acid (TBARS), the conjugated dienes (CD), the carbonyl proteins (CP) and the advanced protein oxidation products (AOPP). Furthermore, it restored the hematology parameters such as white blood cells (WBC), lymphocytes (LYM), and platelets (PLT). In addition, it increased the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). In UDEO-treated rats, the histopathological examinations of the paws revealed little infiltration of inflammatory cells. The decrease in paw edema and human cell lines HeLa cytotoxicity showed that UDEO possesses anti-inflammatory and antioxidant properties, which could be attributed to the high amount of phenolic and flavonoid contents.

Calcination process of porous metal–organic frameworks derived from nickel sulfide composites for supercapacitor and computer vision for investigating the porosity-electrochemical correlation

The utilization of metal–organic framework nanostructured electrode materials in supercapacitors and sensor applications is achieved by various chemical methods. In this study, we create NiS and NiS@MOF-BDC by employing nickel precursors and benzene dicarboxylic acid (BDC) as chelating organic linkers through a thermal reduction procedure at a temperature of 400 °C to produce the composite. The composite heterostructure enhanced the conductivity, porous characteristics, and diverse potential morphological qualities. The production of composite electrodes demonstrates a specific capacity of 260F/g (104C/g) when subjected to a current density of 1A/g. Additionally, these electrodes exhibit exceptional cyclic stability, enduring 5000 cycles, when used with a 2 M KOH electrolyte. Moreover, the synthesized composite HR-TEM images were analyzed using computer vision and AI techniques for estimating the porosity and investigating the enhanced electrochemical correlation.

Seagrass as a potential nutraceutical to decrease pro-inflammatory markers

BackgroundThe Pro-inflammatory mediators such as prostaglandin E2, nitric oxide and TNF-α are the key players in the stimulation of the inflammatory responses. Thus, the pro-inflammatory mediators are considered to be potential targets for screening nutraceutical with anti-inflammatory activity.MethodsIn this context, we explored the anti-inflammatory potency of seagrass extract with western blot (Bio-Rad) analysis by using LPS induced RAW macrophages as in-vitro models, western blot analysis, In-silico methods using Mastero 13.0 software.ResultsThe anti-inflammatory activity of Seagrass was demonstrated through down regulation of Pro-inflammatory markers such as Cyclooxygenase-2, induced Nitric oxide synthase and prostaglandin E synthase-1. The results were validated by docking the phytochemical constituents of seagrass namely Isocoumarin, Hexadecanoic acid, and Cis-9 Octadecenoic acid, 1,2 Benzene dicarboxylic acid and beta-sitosterol with TNF-alpha, COX-2, iNOS and PGES-1.ConclusionThe methanolic extract of seagrass Halophila beccarii is a potential nutraceutical agent for combating against inflammation with a significant anti-inflammatory activity.

Detection of phytoconstituents present in Spirulina platensis extract by GC-MS analysis and their formulation activities against Fusarium oxysporum f.sp. vanillae

Abstract Spirulina platensis represents promising sources of bioactive compounds for pharmaceutical and industrial applications. This study aimed to determine the active compounds in S. platensis extracts (SpE) formulation with three different solvents and in vitro testing against Fusarium oxysporum f.sp.vaniliae. This study was conducted from January to July 2023. Identification of the active compounds present in the three SpE formulations was carried out using the GC-MS method. The effectiveness of SpE formulations was carried out with an inhibition test on F. oxysporum using a completely randomized design (CRD). Based on the results of GC-MS analysis, it is known that the main compounds present in the SpE formulation with ethanol solvent (F1) are trilinolein (48.35%), nonadecatriene (12.50%) and cis-9-hexadecenal (6.47%). SpE formulations using ethyl acetate solvent (F2) are cis-9-hexadecenal (19.53%) and benzene dicarboxylic acid (10.73%). SpE formulations using hexane solvent (F3) are oxacycloheptadec (24.83%) and octadecanoic acid (10.41%). Based on the results of Particle Size Analysis (PSA), it is known that the F1 formulation measures 59.22 µm, the F2 (7.22 µm), and the F3 (7.84 µm). The effectiveness testing of the three formulations showed that the SpE formulation with different solvents effectively inhibited the growth of the fungus F. oxysporum with an average inhibition of 8.41% - 100% compared to the control. F2 treatment with 10% and 15% concentrations resulted in the highest inhibition effect, namely 100%. The 10% and 15% concentrations in the F1 treatment were 8.41% and 39.67%, respectively. The F3 treatment produced 0% inhibition because the growth of the fungus F. oxysporum was better than that of the control. This study implies that SpE formulation with ethanol and ethyl acetate solvents has the potential as an antifungal, especially for F. oxysporum. From this study, the active compounds that act as antifungals are cis-9-hexadecenal, benzene dicarboxylic acid and diisooctyl phthalate.

Chemical Profiling of Essential Oil Extracted from Fresh Walang Leaves (Etlingera walang (Blume) R. M. Sm.), an Indigenous Species in Banten, Indonesia

Essential oils are a group of secondary metabolite compounds that have a distinctive aroma and are volatile. Walang leaves are one of the plants suspected of having essential oil content. This study aims to determine the constituent components of essential oil compounds from fresh walang leaves. The method used to extract essential oil from fresh walang leaves is steam distillation. The essential oil produced was analyzed using Gas Chromatography Mass Spectroscopy (GC-MS). The results showed that the essential oil of fresh walang leaves contained 15 components of essential oil compounds and 2 main components of essential oil compounds, namely: Acetic acid (CAS) Ethylic acid 24.52%, 1,2 Benzenedicarboxylic acid, bis(2-methylpropyl) ester (CAS) Isobutyl phthalate 21.09%.

Zirconium-based hydrophobic-MOFs as innovative electrode modifiers for flibanserin determination: Exploring the electrooxidation mechanism using a comprehensive spectroelectrochemical study.

Threedifferent types of Zr-based MOFs derived from benzene dicarboxylic acid (BDC) and naphthalene dicarboxylic acid as organic linkers (ZrBDC, 2,6-ZrNDC, and 1,4-ZrNDC) were synthesized. They were characterized using X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform IR spectroscopy (FT-IR), and Transmission electron microscopy (TEM). Their hydrophilic/hydrophobic nature was investigated via contact angle measurements; ZrBDC MOF was hydrophilic and the other two (ZrNDC) MOFs were hydrophobic. The three MOFs were combined with MWCNTs as electrode modifiers for the determinationof a hydrophobic analyte, flibanserin (FLB), as a proof-of-concept analyte. Under the optimized experimental conditions, a significant enhancement in the oxidation peak current of FLB was observed when utilizing 2,6-ZrNDC and 1,4-ZrNDC, being the highest when using 1,4-ZrNDC. Furthermore, a thorough investigation of the complex oxidation pathway of FLB was performed by carrying out simultaneous spectroelectrochemical measurements. Based on the obtained results, it was verified that the piperazine moiety of FLB is the primary site for electrochemical oxidation. The fabricated sensor based on 1,4-ZrNDC/MW/CPE showed an oxidation peak of FLB at 0.8V vs Ag/AgCl. Moreover, it showed excellent linearity for the determinationof FLB in the range 0.05 to 0.80μmol L-1 with a correlation coefficient (r) = 0.9973 and limit of detection of 3.0nmol L-1. The applicability of the developed approach was demonstrated by determinationof FLB in pharmaceutical tablets and human urine samples with acceptable repeatability (% RSD values were below 1.9% and 2.1%, respectively) and reasonable recovery values (ranged between 97 and 103% for pharmaceutical tablets and between 96 and 102% for human urine samples). The outcomes of the suggested methodology can be utilized for the determinationof other hydrophobic compounds of pharmaceutical or biological interest with the aim of achieving low detection limits of these compounds in various matrices.

Identification and In-Silico Profiling of Phytoconstituents in Leaves of Punica grantum L.

Punica granatum L. also called Pomegranate, a valuable fruit belonging to Punicaceae family. Pomegranate is not only nutrious but has remarkable medicinal properties. This study aimed to identify the phytochemical constituents present in Pomegranate leaves utilizing Gas Chromatography-Mass Spectrometry (GC-MS) technique, and to assess their medicinal potential using the PASS online software. The results of the analysis revealed the presence of several important phytochemicals, like Neophytadiene,Phytol,1,2 Benzene Dicarboxylic acid known for their medicinal properties such as Saccharopepsin inhibitor, Retinol dehydrogenase inhibitor, anti-inflammatory, anti-pyretic and anti-cancer. From the screened potent compounds, notably Phytol showed good activity which can be further evaluated for in-vivo drug evaluation. This study contributes to the understanding of the phytochemical composition and medicinal potential of Pomegranate leaves, highlighting its significance as a valuable natural resource for pharmaceutical research and development.

3D WO3/BiMOF/Bi2WO6 with rich vacancies defects self-assembled via H2BDC anchoring Bi source of Bi2WO6 for high-performance visible light-driven nitrogen fixation and organic pollutant degradation

A novel photocatalyst WO3/BiMOF/Bi2WO6 was prepared by self-assembly of benzene dicarboxylic acid ligand (H2BDC) anchoring Bi source on the surface of Bi2WO6 to form BiMOF, in which WO3 spherical particles were scattered uniformly. Thereby, an amount of metal and oxygen vacancies (VM + O) are generated. The 3D flower-like spherical photocatalyst has a large specific surface area and close interfacial contacts, which can provide sufficient channels for carrier migration. The introduction of BiMOF enhanced the light absorption capability of photocatalyst. As a result, the flower-like WO3/BiMOF/Bi2WO6 structure exhibits excellent nitrogen fixation as well as high-level photocatalytic activity in degrading Rhodamine B (RhB) and tetracycline (TC) under visible light. For one thing, WO3/BiMOF/Bi2WO6 produce ammonia up to 227 μmol L−1 h−1. For another, the degradation efficacy displayed by RhB 99.3% in 15 min and TC 93.6% degradation in 50 min, respectively. In addition, the catalysts showed excellent cyclic stability, with constant degradation efficiencies for at least 4 cycles. The experimental results of free radical scavenging showed that holes (h+) and superoxide radical (·O2−) were the main active substances in the photodegradation process. Therefore, the photocatalytic mechanism of 3D flower-like WO3/BiMOF/Bi2WO6 was also proposed.

Cobalt and copper-based metal-organic frameworks synthesis and their supercapacitor application

In this study, two different metal-organic frameworks (MOFs) were synthesized using copper and cobalt metal ions with benzenedicarboxylic acid (bdc) as a common ligand. The prepared MOFs were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy-energy dispersive spectroscopy. Also, the electrochemical characteristics were analyzed using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy methods. Structural characterizations indicate that Co-bdc MOF is composed of three-dimensional non-uniform colloids and Cu-bdc MOF has a regular three-dimensional cuboidal structure, possessing good crystalline structure. The Cu-bdc MOF exhibited a maximum specific capacitance of 171 F/g, while Co-bdc MOF showed 368 F/g at the current density of 1 A/g. The solution resistance for the Co-bdc MOF was 0.09 Ω in comparison to 1.25 Ω for the Cu-bdc MOF. Also, the Co-bdc MOF demonstrated better cycling performance by retaining 85 % of its capacity after 2000 charge-discharge cycles. In contrast, the stability of the Cu-bdc MOF was lower, with only 78 % retention in capacity. Conclusively, the Co-bdc MOF demonstrated superior specific capacitance, lower resistance, and enhanced cyclic stability in 3 M KOH electrolyte system.

Environmental enrichment improves social isolation-induced memory impairment: The possible role of ITSN1-Reelin-AMPA receptor signaling pathway.

Environmental enrichment (EE) through combination of social and non-biological stimuli enhances activity-dependent synaptic plasticity and improves behavioural performance. Our earlier studies have suggested that EE resilience the stress induced depression/ anxiety-like behaviour in Indian field mice Mus booduga. This study was designed to test whether EE reverses the social isolation (SI) induced effect and improve memory. Field-caught mice M. booduga were subjected to behaviour test (Direct wild, DW), remaining animals were housed under SI for ten days and then housed for short-term at standard condition (STSC)/ long-term at standard condition (LTSC) or as group in EE cage. Subsequently, we have examined reference, working memory and expression of genes associated with synaptic plasticity. Our analysis have shown that EE reversed SI induced impairment in reference, working memory and other accompanied changes i.e. increased level of Intersectin 1 (ITSN1), Huntingtin (Htt), Synaptotagmin -IV (SYT4), variants of brain-derived neurotrophic factor (Bdnf - III), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor (GluR1) expression, and decreased variants of Bdnf (IV), BDNF, Reelin, Apolipoprotein E receptor 2 (ApoER2), very low-density lipoprotein receptor (VLDLR), Src family tyrosine kinase (SFKs), Disabled protein (Dab)-1, Protein kinase B (PKB/Akt), GluR2, Mitogen-activated protein kinase (MAPK) and Extracellular signal-regulated kinase (ERK1/2) expression. In addition, SI induced reduction in BDNF expressing neurons in dentate gyrus of hippocampus reversed by EE. Further, we found that SI decreases small neuro-active molecules such as Benzenedicarboxylic acid, and increases 2-Pregnene in the hippocampus and feces reversed by EE. Overall, this study demonstrated that EE is effectively reversed the SI induced memory impairment by potentially regulating the molecules associated with the ITSN1-Reelin-AMPA receptor pathway to increase synaptic plasticity.

Label-free and early detection of HER2 breast cancer biomarker based on UiO-66-NH2 modified gold chip (Au/UiO-66-NH2) using surface plasmon resonance technique

Breast cancer is one of the leading causes of cancer death for women worldwide. This cancer occurs when the breast cells grow abnormally and spread uncontrolled. Although there are several treatments, including chemotherapy, radiation, and surgery in a clinical setting to cure cancer, these treatments cannot provide a 100 % success rate in eliminating cancer, mainly due to the late diagnosis of the disease. Thus, early detection is the key to provide better breast cancer treatment and a higher chance for survival. Herein, simple and sensitive biosensor by combining the emerging multifunctional materials of metal-organic frameworks (MOFs) with a label-free surface plasmon resonance (SPR) instrument was developed. Two types of stable Zirconium (Zr)-based MOFs, namely Zr benzene dicarboxylic acid (Zr-BDC or UiO-66) and Zr 2-amino-benzene dicarboxylic acid (Zr-BDC-NH2 or UiO-66-NH2) were synthesized using the solvothermal method. X-ray diffractometer (XRD) and fourier transform infra red (FTIR) confirmed the formation of the prepared UiO-66 and UiO-66-NH2. The electron microscopy and nitrogen adsorption desorption isotherm characterization reveal that the MOFs have a cubic crystal structure with a high surface area of 672.4 m2/g for UiO-66 and 286.1 m2/g for UiO-66-NH2. The MOFs are then functionalized on the SPR gold (Au) chip surface to serve as a matrix of Human Epidermal Growth Factor Receptor 2(HER2) antibody receptors. Interestingly, the functionalized SPR biosensors could detect the HER2 protein target with high sensitivity in the ng/mL range and a remarkable detection limit, which is 0.457 ng/mL for UiO-66-NH2. This LOD value is significantly lower than clinical concentrations of HER2 proteins in human blood (∼15 ng/mL), which indicate that the biosensor can offer the capability of early detection test.

Antibacterial Activities of Secondary Metabolites Derived from Streptomyces sp. VITGV38 (MCC4869) against Selected Uropathogens

Streptomyces sp. VITGV38 (MCC8469) was obtained from the VIT University Microbiology Laboratory where it was isolated from tomato plants. This strain was mass-cultured for 15 days and its extracellular metabolites were extracted in ethyl acetate using a liquid–liquid extraction method. The antibacterial test was performed on the ethyl acetate crude extract against selected urinary tract pathogens, Proteus mirabilis (MTCC-442), Enterococcus faecalis (MTCC-439), Klebsiella pneumoniae (MTCC-109), and Escherichia coli (MTCC-1687), The extract developed a clear inhibition zone that measured between 17–21 mm. The minimum inhibition concentration was observed from a concentration of 25 μg/ml against all selected uropathogens. GC-MS analysis revealed 35 diverse compounds in the ethyl acetate crude extract, which includes 1,2 benzenedicarboxylic acid bis(2methylpropyl) ester, dibutyl phthalate, bis (2-ethylhexyl) phthalate, didodecyl phthalate, octadecanoic acid dodecyl ester, and dodecane. These six compounds are the major antimicrobial compounds present in the ethyl acetate extract. VITGV38 showed greyish aerial mycelium. Scanning electron microscopy revealed elliptical spores with a chain-like smooth orientation.

In Situ Growth of Sub-50-nm Zirconium Aminobenzenedicarboxylate Metal-Organic Framework Nanocrystals for Carbon Dioxide Capture.

Controlled synthesis of sub-50-nm metal-organic frameworks (MOFs), which are usually called porous coordination polymers, exhibits huge potential applications in gas storage and separation. Herein, surface-confined growth of zirconium aminobenzenedicarboxylate MOF (UIO-66-NH2) nanocrystals on polypyrrole hollow spheres (PPyHSs) is achieved through covalently grafted benzene dicarboxylic acid ligands using bridged molecules. PPyHSs modified with ligand molecules prohibit excessive growth of UIO-66-NH2 nanocrystals on their confined surface, resulting in smaller-sized nanocrystals (<50 nm) and a monolayer UIO-66-NH2 coating. Benefiting from the homogeneous dispersion of UIO-66-NH2 nanocrystals with a smaller size (40 ± 10 nm), the as-prepared PPyHSs@UIO-66-NH2 hybrids with high specific surface area and pore volume exhibit remarkable CO2 capture performance. Moreover, the time required to reach the maximum CO2 adsorption capacity shortens with decreasing UIO-66-NH2 crystals size. As a proof of concept, the proposed covalent grafting strategy can be used for synthesizing sub-50-nm UIO-66-NH2 nanocrystals for CO2 capture.

Enzymatic degradation and metabolic pathway of phenanthrene by manglicolous filamentous fungus Trichoderma sp. CNSC-2

Manglicolous filamentous fungi release extracellular lignolytic enzymes that can readily degrade polycyclic aromatic hydrocarbons (PAHs). The present study emphasizes the role of the extracellular enzyme in phenanthrene degradation by the manglicolous fungus Trichoderma sp. CNSC-2 isolated from the Indian Sundarban mangrove ecosystem. The removal efficiency reached 64.05 ± 0.75 % in 50 mg l−1 phenanthrene-amended mineral salt medium at pH 5.6 after 10 days of incubation. Phenanthrene removal was optimized at different pH, nutrient sources, and Cu2+ concentrations. The degradation significantly increased to 67.75 ± 4.32 % at pH 6 (P < 0.0001). The addition of Cu2+ (30 mg l−1) increased the degradation to 78.15 ± 0.36 % (P < 0.0001). The validation experiment confirmed the increase in phenanthrene degradation up to 79.9 ± 1.67 % under optimized conditions. The Lac1 and CytP450 genes encoding for extracellular and intracellular enzymes, respectively, were identified. The GC-MS derived phenanthrene degradation metabolites, i.e., phthalic acid, isobutyl 2-pentyl ester derivative, 1, 2 benzene dicarboxylic acid, butyl 2-methyl propyl ester derivative, TMS derivative of benzoic acid and 3,5 dihydroxy benzoic acid determined two possible metabolic pathways. The laccase enzyme activity was higher in the presence of Phe+Cu2+ (P < 0.0001), indicating the enzyme induction potential of PAH and Cu2+ ions. Purified laccase had a molecular weight of 45 kDa and was highly stable at pH 4–6 and temperature 20–50 °C. The enzyme retained 47 %, 87 %, and 63 % of enzyme activity at 30 mg l−1 concentration of Pb2+, Cd2+, and Hg2+. However, laccase activity was induced by 1.37 folds in the presence of 30 mg l−1 Cu2+ concentration. Thus, the study suggests the potential role of Trichoderma sp. CNSC-2 in phenanthrene degradation.

Upcycling plastic waste: Rapid aqueous depolymerization of PET and simultaneous growth of highly defective UiO-66 metal-organic framework with enhanced CO2 capture via one-pot synthesis

UiO-66(Zr) MOF was synthesized rapidly via one-pot synthesis in an acidic aqueous media starting with waste polyethylene terephthalate (PET) plastic flakes and Zr metal salt. Complete depolymerization of PET into BDC (benzene dicarboxylic acid) linkers and coordination with Zr metal clusters occurred in 30 mins under microwave irradiation. PET-derived UiO-66 showed a large micron-sized cuboctahedron crystal structure with high microporosity. The use of acetic acid as a modulator helps to increase the reo-topology defect within the MOFs improving CO2 uptake. PET-derived UiO-66 exhibited intense reo-defects than UiO-66 synthesized using a pristine BDC linker. This was likely due to the one-pot reaction of PET depolymerization with simultaneous MOF growth that results in an enhanced competition of modulator and byproducts formed during PET digestion along with the BDC to bind with Zr clusters inducing more defects in the structure. Heat treatment of the PET-derived UiO-66 with the optimal mole ratio of 1Zr:1PET yields UiO-66 with the highest BET surface area of 1200 m2g−1 and a total pore volume of 0.57 cm3g−1. The highest CO2 uptake of 2.06 mmolg−1 was shown by 1Zr:1PET, due to their high microporosity and profound reo-structure which demonstrated superior CO2 uptake than the UiO-66 synthesized using commercial BDC. The selectivity of the CO2 over N2 was over 25.3 times and exhibited excellent regeneration stability and recyclability over 5 cycles with 99% of persistent CO2 sorption capacity. This study demonstrated the utilization and recycling of PET waste to BDC linkers with simultaneous MOF growth which have a high potential to capture CO2 effectively.

Bioassay-guided isolation and in silico study of antihyperlipidemic compounds from Onosma hispidum Wall

Isolation of bioactive compounds from plants and their therapeutic evaluation is crucial in the pursuit of novel phytochemicals and contributes an indispensable role in drug discovery and design. The literature has documented the hypolipidemic effect of numerous Onosma species. Taking that into consideration, the current study was designed to isolate, purify and evaluate the antihyperlipidemic potential of leaves of Onosma hispidum Wall. For the first time, the bioassay-guided isolation led to the separation of 3 compounds that were identified by spectroscopic techniques as o-phthalic acid bis-(2-ethyl decyl)-ester (1), bis (2-ethyloctyl) phthalate (2), and 1,2 benzenedicarboxylic acid bis(2-methyl heptyl) ester (3). Lipase inhibition assay was utilized to scrutinize the antihyperlipidemic potential of methanolic extract fractions and subsequently isolated compounds. Further, the isolated compounds were employed for in silico studies via molecular docking, molecular mechanics with generalized born and surface area solvation (MM-GBSA), and MD simulations with Pancreatic Lipase Colipase (PDB ID: 1LPB). Molecular docking and MM-GBSA of isolated compounds were employed to explain the mode of binding between the protein–ligand complex and binding free energy calculation, respectively. Since compound (3) displayed the best docking score of −6.689 kcal/mol as compared to orlistat −5.529 kcal/mol with PDB: 1LPB. So, it was chosen for MD simulations to evaluate ligand stability and flexibility of the complex which was validated by the fluctuation of α-carbon chain, root mean square deviation (RMSD), root mean square fluctuation (RMSF), and type of interactions involved which authenticated the in vitro lipase inhibitory potential. Overall, in silico and in vitro results validated that compound (3) could be exploited as a promising pancreatic lipase inhibitor. Communicated by Ramaswamy H. Sarma

SAW Sensor with Langmuir-Blodgett Layer for Detection of Benzene and its Derivatives

Vapors of benzene and its derivatives are harmful and toxic for human beings and natural environment. Their detection has fundamental importance. For this purpose authors propose surface acoustic wave (SAW) sensor with skeletonized layer deposited by Langmuir-Blodgett (L-B) method. This layer was obtained by depositing a binary equimolar mixture of 5-[[1,3-dioxo-3-[4-(1-oxooctadecyl) phenyl]propyl]amino]–1,3–benzenedicarboxylic acid with cetylamine. The skeletonized sensor layer has been obtained by removing cetylamine. Response of this sensor depends mainly of the electrical dipole momentum of molecule. Among the tested compounds, benzene has a zero dipole moment and gives the smallest sensor response, and nitrobenzene has the largest dipole moment and the sensor reacts most strongly to its vapor.