RESUMO
The excessive emission of greenhouse gases, which leads to global warming and alarms the world, has triggered a global campaign for carbon neutrality. Carbon capture and sequestration (CCS) technology has aroused wide research interest as a versatile emission mitigation technology. Metal-organic frameworks (MOFs), as a new class of high-performance adsorbents, hold great potential for CO2 capture from large point sources and ambient air due to their ultra-high specific surface area as well as pore structure. In recent years, MOFs have made great progress in the field of CO2 capture and separation, and have published a number of important results, which have greatly promoted the development of MOF materials for practical carbon capture applications. This review summarizes the most recent advanced research on MOF materials for carbon capture in various application scenarios over the past six years. The strategies for enhancing CO2 selective adsorption and separation of MOFs are described in detail, along with the development of MOF-based composites. Moreover, this review also systematically summarizes the highly concerned issues of MOF materials in practical applications of carbon capture. Finally, future research on CO2 capture by MOF materials is prospected.
RESUMO
The capacity to emit isoprene, among other stresses, protects plants from drought, but the molecular mechanisms underlying this trait are only partly understood. The Arecaceae (palms) constitute a very interesting model system to test the involvement of isoprene in enhancing drought tolerance, as their high isoprene emissions may have contributed to make them hyperdominant in neotropical dry forests, characterized by recurrent and extended periods of drought stress. In this study we isolated and functionally characterized a novel isoprene synthase, the gene responsible for isoprene biosynthesis, from Copernicia prunifera, a palm from seasonally dry tropical forests. When overexpressed in the non-emitter Arabidopsis thaliana, CprISPS conferred significant levels of isoprene emission, together with enhanced tolerance to water limitation throughout plant growth and development, from germination to maturity. CprISPS overexpressors displayed higher germination, cotyledon/leaf greening, water usage efficiency, and survival than WT Arabidopsis under various types of water limitation. This increased drought tolerance was accompanied by a marked transcriptional up-regulation of both ABA-dependent and ABA-independent key drought response genes. Taken together, these results demonstrate the capacity of CprISPS to enhance drought tolerance in Arabidopsis and suggest that isoprene emission could have evolved in Arecaceae as an adaptive mechanism against drought.
Assuntos
Arabidopsis , Arecaceae , Arabidopsis/metabolismo , Árvores/genética , Ácido Abscísico , Resistência à Seca , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Arecaceae/genética , Estresse Fisiológico/genética , Secas , Água , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
Baeyer-Villiger monooxygenases (BVMOs) are remarkable biocatalysts for the Baeyer-Villiger oxidation of ketones to generate esters or lactones. The regioselectivity of BVMOs is essential for determining the ratio of the two regioisomeric products ("normal" and "abnormal") when catalyzing asymmetric ketone substrates. Starting from a known normal-preferring BVMO sequence from Pseudomonas putida KT2440 (PpBVMO), a novel BVMO from Gordonia sihwensis (GsBVMO) with higher normal regioselectivity (up to 97/3) was identified. Furthermore, protein engineering increased the specificity constant (kcat /KM ) 8.9-fold to 484â s-1 mM-1 for 10-ketostearic acid derived from oleic acid. Consequently, by using the variant GsBVMOC308L as an efficient biocatalyst, 10-ketostearic acid was efficiently transformed into 9-(nonanoyloxy)nonanoic acid, with a space-time yield of 60.5â g L-1 d-1 . This study showed that the mutant with higher regioselectivity and catalytic efficiency could be applied to prepare medium-chain ω-hydroxy fatty acids through biotransformation of long-chain aliphatic keto acids derived from renewable plant oils.
Assuntos
Oxigenases de Função Mista/metabolismo , Engenharia de Proteínas , Actinobacteria/enzimologia , Biocatálise , Oxigenases de Função Mista/genética , Mutagênese Sítio-Dirigida , Ácido Oleico/química , Ácido Oleico/metabolismo , Oxirredução , Pseudomonas putida/enzimologia , Ácidos Esteáricos/química , Ácidos Esteáricos/metabolismo , Estereoisomerismo , Especificidade por SubstratoRESUMO
Clenbuterol (CLE) and ractopamine (RAC) are two kinds of typical ß2-adrenergic agonists which pose a serious threat to the health of human beings. In this work, 10 kinds of metal-organic frameworks (MOFs) with high stability and various pore features are screened to assess adsorption performance for CLE and RAC. An Al(III)-MOF (BUT-19) with abundant ethyl groups exhibits exceptional performance in removing CLE and RAC from water. The maximum adsorption capacity for CLE and RAC are up to 294.1 and 366.3 mg/g under the optimum adsorption conditions, respectively. Meanwhile, the adsorption mechanism effects of pH, temperature, and coexisted ions are investigated systematically. It is found that the MOF pore size and weak hydrogen-bond interactions between CLE/RAC molecules and the MOF are the main causes leading to the extraordinary adsorption. This study provides a new idea for the purposeful design and synthesis of MOFs for removing environmental pollutants and sheds light on the depuration of contaminated water.
Assuntos
Alumínio/química , Clembuterol/isolamento & purificação , Estruturas Metalorgânicas/química , Fenetilaminas/isolamento & purificação , Clembuterol/química , Estrutura Molecular , Fenetilaminas/química , Poluentes Químicos da ÁguaRESUMO
BACKGROUND: Setting effects are different for each fish species tested. There is no published literature on the response of Amur sturgeon (Acipenser schrenckii) to increased setting times. This study investigated the effects of high-temperature setting (40 °C) for different durations on the gel properties of A. schrenckii surimi. As A. schrenckii is a new surimi material, it is also necessary to conduct a sensory evaluation and to report the surimi yields. RESULTS: Increasing setting durations (0.5-1.5 h) significantly improved the gel properties. The best results in terms of molecular forces, gel strength, texture profile analysis (TPA), water holding capacity (WHC), and whiteness were obtained by the gels with setting durations of 1 and 1.5 h. The protein degradation detected as a result of extended setting durations (>2 h) significantly decreased the gel properties. The most inferior gel properties were shown by the gel with setting for 3 h. Protein degradation also resulted in higher cooking loss and poor microstructures. The sensory evaluation indicated that A. schrenckii surimi was generally accepted by the panelists in terms of color, texture, and aroma. The surimi yield obtained in this study was 32.4%, which was similar to commercial surimi and higher than several surimi yields in recent studies. CONCLUSION: Setting durations from 0.5 to 1.5 h can be implemented to improve the properties of A. schrenckii surimi. Extended durations (>2 h) must be avoided. Overall, this work provided some necessary information about setting response, gel properties, sensory evaluation, and surimi yield in A. schrenckii, which will be useful for further studies. © 2020 Society of Chemical Industry.
Assuntos
Produtos Pesqueiros/análise , Proteínas de Peixes/química , Animais , Peixes , Manipulação de Alimentos , Géis/química , Temperatura Alta , Humanos , PaladarRESUMO
This Review focuses on research oriented toward elucidation of the various aspects that determine adsorption of CO2 in metal-organic frameworks and its separation from gas mixtures found in industrial processes. It includes theoretical, experimental, and combined approaches able to characterize the materials, investigate the adsorption/desorption/reaction properties of the adsorbates inside such environments, screen and design new materials, and analyze additional factors such as material regenerability, stability, effects of impurities, and cost among several factors that influence the effectiveness of the separations. CO2 adsorption, separations, and membranes are reviewed followed by an analysis of the effects of stability, impurities, and process operation conditions on practical applications.
RESUMO
Baeyer-Villiger monooxygenases (BVMOs) are versatile biocatalysts in organic synthesis that can generate esters or lactones by inserting a single oxygen atom adjacent to a carbonyl moiety. The regioselectivity of BVMOs is essential in determining the ratio of two regioisomers for converting asymmetric ketones. Herein, we report a novel BVMO from Pseudomonas aeruginosa (PaBVMO); this has been exploited for the direct synthesis of medium-chain α,ω-dicarboxylic acids through a Baeyer-Villiger oxidation-hydrolysis cascade. PaBVMO displayed the highest abnormal regioselectivity toward a variety of long-chain aliphatic keto acids (C16 -C20 ) to date, affording dicarboxylic monoesters with a ratio of up to 95 %. Upon chemical hydrolysis, α,ω-dicarboxylic acids and fatty alcohols are readily obtained without further treatment; this significantly reduces the synthetic steps of α,ω-dicarboxylic acids from renewable oils and fats.
Assuntos
Ácidos Carboxílicos/metabolismo , Oxigenases de Função Mista , Pseudomonas aeruginosa/metabolismo , Biocatálise , Ácidos Dicarboxílicos/metabolismo , Ésteres/metabolismo , Hidrólise , Isomerismo , Cetoácidos/metabolismo , Cetonas/metabolismo , Lactonas/metabolismo , Oxigenases de Função Mista/química , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Oxirredução , Especificidade por SubstratoRESUMO
The removal of C2 H2 and C2 H6 from C2 H4 streams is of great significance for feedstock purification to produce polyethylene and other commodity chemicals but the simultaneous adsorption of C2 H6 and C2 H2 over C2 H4 from a ternary mixture has never been realized. Herein, a robust metal-organic framework, TJT-100, was designed and synthesized, which demonstrates remarkably selective adsorption of C2 H2 and C2 H6 over C2 H4 . Breakthrough experiments show that TJT-100 can be used as an adsorbent for high-performance purification of C2 H4 from a ternary mixture of C2 H2 /C2 H4 /C2 H6 (0.5:99:0.5) to afford a C2 H4 purity greater than 99.997 %, beyond that required for ethylene polymerization. Computational studies reveal that the uncoordinated carboxylate oxygen atoms and coordinated water molecules pointing towards the pore can trap C2 H2 and C2 H6 through the formation of multiple C-Hâ â â O electrostatic interactions, while the corresponding C2 H4 -framework interaction is unfavorable.
RESUMO
Three new water-stable In(III)-based metal-organic frameworks, namely, [In3(TTTA)2(OH)3(H2O)]·(DMA)3 (BUT-70, DMA = N,N-dimethylacetamide), [In3(TTTA)2(CH3O)3] (BUT-70A), and [In3(TTTA)2(OH)3] (BUT-70B), with rod-shaped secondary building units (SBUs) and an new acrylate-based ligand, (2E,2'E,2â³E)-3,3',3â³-(2,4,6-trimethylbenzene-1,3,5-triyl)-triacrylate (TTTA3-) were obtained and structurally characterized. BUT-70A and -70B were generated in a single-crystal to single-crystal transformation fashion from BUT-70 through guest exchange followed by their removal. The solvents used for guest exchange were methanol and dichloromethane, respectively. Single-crystal structure analyses show that the guest exchange and removal process is accompanied by the substitution of coordinated water molecules of In(III) centers with uncoordinated carboxylate O atoms of TTTA3- ligands. Moreover, hydroxyl groups bridging two In(III) centers are also replaced by methoxyl groups in the transformation from BUT-70 to -70A. Overall, three metal-organic frameworks (MOFs) are constructed by infinite chains consisting of corner-sharing InO4(OR)2 (R = H or Me) octahedral entities, which are interconnected by TTTA3- ligands to form three-dimensional frameworks. Unlike most reported MOFs with infinite chains as SBUs, such as well-known MIL-53 and M-MOF-74, which have one-dimensional channels along the chain direction, the BUT-70 series contain two-dimensional intersecting channels. The Brunauer-Emmett-Teller surface area and pore volume of BUT-70A were estimated to be 460 m2 g-1 and 0.18 cm3 g-1, respectively, which are obviously lower than those of BUT-70B (695 m2 g-1 and 0.29 cm3 g-1). Gas adsorption experiments demonstrated that BUT-70A and -70B are able to selectively adsorb C2H2 over CO2 and CH4. At 1 atm and 298 K, BUT-70A uptakes 3.1 mmol g-1 C2H2, which is 3.6 times that of the CO2 uptake and 7.2 times that of the CH4 uptake. Compared with BUT-70A, BUT-70B presents an even higher C2H2 uptake of 3.9 mmol g-1 at the same conditions, but slightly lower Ideal Adsorbed Solution Theory C2H2/CO2 and C2H2/CH4 selectivities.
RESUMO
BACKGROUND: Immunogenic cell death (ICD) is a specific form of regulated cell death induced by a variety of stressors. During ICD, the dying cancer cells release damage-associated molecular patterns (DAMPs), which promote dendritic cell maturation and tumor antigen presentation, subsequently triggering a T-cell-mediated anti-tumor immune response. In recent years, a growing number of studies have demonstrated the potential of natural products to induce ICD and enhance tumor cell immunogenicity. Moreover, there is an increasing interest in identifying new ICD inducers from natural products. PURPOSE: This study aimed to emphasize the potential of natural products and their derivatives as ICD inducers to promote research on using natural products in cancer therapy and provide ideas for future novel immunotherapies based on ICD induction. METHOD: This review included a thorough search of the PubMed, Web of Science, Scopus, and Google Scholar databases to identify natural products with ICD-inducing capabilities. A comprehensive search for clinical trials on natural ICD inducers was also conducted using ClinicalTrials.gov, as well as the approved patents using the Espacenet and CNKI Patent Database. RESULTS: Natural compounds that induce ICD can be categorized into several groups, such as polyphenols, flavonoids, terpenoids, and alkaloids. Natural products can induce the release of DAMPs by triggering endoplasmic reticulum stress, activation of autophagy-related pathways, and reactive oxygen species generation, etc. Ultimately, they activate anti-tumor immune response and improve the efficacy of cancer treatments. CONCLUSION: A growing number of ICD inducers from natural products with promising anti-cancer potential have been identified. The detailed information presented in this review will contribute to the further development of natural ICD inducers and cancer treatment strategies based on ICD-induced responses.
RESUMO
Pure surimi of silver carp (Hypophthalmichthys molitrix) cannot meet the texture requirements in novel 3D printing of food. In this work, the effect mechanism of adding soluble pectin fiber on the quality of surimi was studied at molecular scale, and the interaction has been discussed by a novel prediction model. In comparison with pure surimi, pH and water-holding capacity decreased with increasing pectin, and texture properties improved. The storage modulus firstly rose and then decreased, reaching a maximum value of 15012 Pa at 0.5 % pectin addition. The thermal transition temperature of myosin was moved from 52.13 to 49.80 °C. Pectin extended the T22 relaxation time, suggesting a decrease in immobilized water. A new Time-series prediction model and interaction analysis further explored the intrinsic correlation of various parameters of surimi with different pectin additions. This work contributes to add our understanding of pectin application in surimi products in future special dietary food.
Assuntos
Carpas , Animais , Produtos Pesqueiros/análise , Pectinas , Géis/química , ÁguaRESUMO
Molecular modeling methods are used to estimate the influence of impurity species: water, O(2), and SO(2) in flue gas mixtures present in postcombustion CO(2) capture using a metal organic framework, HKUST-1, as a model sorbent material. Coordinated and uncoordinated water effects on CO(2) capture are analyzed. Increase of CO(2) adsorption is observed for both cases, which can be attributed to the enhanced binding energy between CO(2) and HKUST-1 due to the introduction of a small amount of water. Density functional theory calculations indicate that the binding energy between CO(2) and HKUST-1 with coordinated water is ~1 kcal/mol higher than that without coordinated water. It is found that the improvement of CO(2)/N(2) selectivity induced by coordinated water may mainly be attributed to the increased CO(2) adsorption on the hydrated HKUST-1. On the other hand, the enhanced selectivity induced by uncoordinated water in the flue gas mixture can be explained on the basis of the competition of adsorption sites between water and CO(2) (N(2)). At low pressures, a significant CO(2)/N(2) selectivity increase is due to the increase of CO(2) adsorption and decrease of N(2) adsorption as a consequence of competition of adsorption sites between water and N(2). However, with more water molecules adsorbed at higher pressures, the competition between water and CO(2) leads to the decrease of CO(2) adsorption capacity. Therefore, high pressure operation should be avoided in HKUST-1 sorbents for CO(2) capture. In addition, the effects of O(2) and SO(2) on CO(2) capture in HKUST-1 are investigated: The CO(2)/N(2) selectivity does not change much even with relatively high concentrations of O(2) in the flue gas (up to 8%). A slightly lower CO(2)/N(2) selectivity of a CO(2)/N(2)/H(2)O/SO(2) mixture is observed compared with that in a CO(2)/N(2)/H(2)O mixture, especially at high pressures, due to the strong SO(2) binding with HKUST-1.
Assuntos
Dióxido de Carbono/química , Compostos Organometálicos/química , Oxigênio/química , Dióxido de Enxofre/química , Água/química , Adsorção , Estruturas Metalorgânicas , Modelos Moleculares , Teoria Quântica , Propriedades de SuperfícieRESUMO
Arabidopsis is by far the plant model species most widely used for functional studies. The surface sterilization of Arabidopsis seeds is a fundamental step required towards this end. Thus, it is paramount to establish high-throughput Arabidopsis seed surface sterilization methods to handle tens to hundreds of samples (e.g., transgenic lines, ecotypes, or mutants) at once. A seed surface sterilization method based on the efficient elimination of liquid in tubes with a homemade suction device constructed from a common vacuum pump is presented in this study. By dramatically reducing labor-intensive hands-on time with this method handling several hundreds of samples in one day is possible with little effort. Series time-course analyses further indicated a highly flexible time range of surface sterilization by maintaining high germination rates. This method could be easily adapted for surface sterilization of other kinds of small seeds with simple customization of the suction device according to the seed size, and the speed desired to eliminate the liquid.
Assuntos
Arabidopsis , Sementes , Esterilização , GerminaçãoRESUMO
Vanillin is a natural phenolic compound mainly used as flavors in food industry. In this work, a new functionality of vanillin as the α-glucosidase inhibitor was studied based on the inhibition kinetic mechanism. The inhibitory effect (IC50) of vanillin against α-glucosidase was 28.34 ± 0.89 mg/mL, which belongs to mixed inhibition mechanism and its process was spontaneous. Vanillin could bind to α-glucosidase by hydrophobic interactions and hydrogen bonds with -8.42 kcal/mol intermolecular energy to form the steric hindrance. The average binding distances was calculated as 2.20 nm according to energy transfer theory. In addition, the protein secondary structure and denaturation temperature (decreasing about 10 °C) were changed significantly after vanillin binding to α-glucosidase, resulting in an inhibitory effect. The findings of this research provide insights for the development of vanillin as potential inhibitor for α-glucosidase in special dietary foods.
Assuntos
Benzaldeídos/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , alfa-Glucosidases/química , alfa-Glucosidases/metabolismo , Benzaldeídos/química , Benzaldeídos/metabolismo , Domínio Catalítico , Dicroísmo Circular , Transferência de Energia , Transferência Ressonante de Energia de Fluorescência , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/metabolismo , Ligação de Hidrogênio , Cinética , Simulação de Acoplamento Molecular , Desnaturação Proteica , Estrutura Secundária de Proteína , TemperaturaRESUMO
Density functional theory calculations were carried out to characterize a series of transition-metal-doped aluminum hydrides, forming TMAl(n)H(2n) and TMAl(n)H(2n+1) (TM = Sc, Ti, V; n = 3,4), in either charged or neutral form. A new electron-counting rule for these clusters was formulated as PSEN (paired skeleton electron number) = 4n, which can characterize both closed-shell and open-shell clusters. On the basis of this electron-counting rule, the superatomic clusters such as TiAl(4)H(9) and TiAl(3)H(6) were identified and can be used to assemble supramolecular structures. Electronic structure analysis showed that three-centered TM-H-Al bonds largely contributed to the structural stability. Also, the spin state of a wide range of clusters in their ground state can be predicted by the electron-counting rule.
RESUMO
The broad spectrum detection of veterinary drugs is very important for rapid and large-scale safe screen of animal-derived foods. Metal-organic frameworks (MOFs), as a kind of emerged functional porous materials are quite promising in the chemical sensing and molecular detection. In this work, we report the high-performance broad spectrum detection of 15 commonly-used veterinary drugs through the fluorescence quenching in a newly-designed chemically stable Al-based MOF, Al3(µ3-O)(OH)(H2O)2(PPTTA)3/2 (BUT-22). To the best of our knowledge, this is the first systematic investigation for the application of MOFs in the detection/sensing of veterinary drugs through fluorescence quenching method. The quenching efficiencies of the tested veterinary drugs on BUT-22 are all beyond 82%, and the limits of detection (LOD) are low at parts per billion (ppb) levels. Interestingly, BUT-22 also enables the selective detection of nicarbazin (NIC) through the clearly-observed red shift of its maximum fluorescence emission wavelength. Moreover, the fluorescence quenching mechanism was explored with the help of theoretical calculations. Our work indicates that MOFs are favorable materials for the detection of veterinary drugs, being potentially useful in monitoring drug residues of animal-derived foods.
Assuntos
Alumínio/química , Estruturas Metalorgânicas/química , Drogas Veterinárias/análise , Adsorção , Ração Animal , Anti-Infecciosos/análise , Anti-Infecciosos/química , Cloranfenicol/análise , Cloranfenicol/química , Fluorescência , Inocuidade dos Alimentos , Limite de Detecção , Nitrofuranos/análise , Nitrofuranos/química , Porosidade , Sulfonamidas/análise , Sulfonamidas/química , Tetraciclinas/análise , Tetraciclinas/química , Drogas Veterinárias/químicaRESUMO
This work studied the effects of KGM with different degrees of deacetylation (DDs) on the physicochemical properties of silver carp (Hypophthalmichthys molitrix) surimi gels. Compared with KGM, deacetylated KGM (DKGM) weakened the water-holding capacity, but increased the gel strength of surimi gels. The storage modulus (G') and loss modulus (G'') of surimi showed an upward trend, and the aggregation rate of surimi with DKGM changed. The number of ionic bonds of mixed surimi gels increased on the whole, but those of hydrogen bonds declined; a hydrophobic interaction was the main driving force, and improved with the DDs of DKGM. FT-IR results indicated that the deacetylation of KGM had a slight influence on the secondary structure of the proteins. SDS-PAGE results showed that DKGM enhanced the intensity of the main heavy chains of myosin and actin. Examination of the network structure of the surimi gels revealed that DKGM might combine around the filaments of myofibrillar proteins like a rosary through hydrophobic interactions and hydrogen bonding. As a consequence, the myfibrillar protein aggregation was changed and the microstructures of the surimi became more compact and fibrous. The results indicated that the deacetylation of KGM led to an increase in hydrophobicity, which influenced the hydrophobic interaction of the myofibrillar proteins. As a result, the aggregation of the myofibrillar proteins was promoted and the physico-chemical properties of the surimi gel were improved.
RESUMO
STRA6 is a multitransmembrane domain protein not homologous to any other proteins with known function. It functions as the high-affinity receptor for plasma retinol binding protein (RBP) and mediates cellular uptake of vitamin A from the vitamin A-RBP complex. Consistent with the diverse roles of vitamin A and the wide tissue expression pattern of STRA6, mutations in STRA6 are associated with severe pathological phenotypes in humans. The structural basis for STRA6's biochemical function is unknown. Although computer programs predict 11 transmembrane domains for STRA6, its topology has never been studied experimentally. Elucidating the transmembrane topology of STRA6 is critical for understanding its structure and function. By inserting an epitope tag into all possible extracellular and intracellular domains of STRA6, we systematically analyzed the accessibility of each tag on the surface of live cells, the accessibility of each tag in permeabilized cells, and the effect of each tag on RBP binding and STRA6-mediated vitamin A uptake from the vitamin A-RBP complex. In addition, we used a new lysine accessibility technique combining cell-surface biotinylation and tandem-affinity purification to study a region of the protein not revealed by the epitope tagging method. These studies not only revealed STRA6's extracellular, transmembrane, and intracellular domains but also implicated extracellular regions of STRA6 in RBP binding.
Assuntos
Membrana Celular/metabolismo , Espaço Extracelular/metabolismo , Receptores de Superfície Celular/química , Receptores de Superfície Celular/metabolismo , Animais , Bovinos , Linhagem Celular , Permeabilidade da Membrana Celular , Sobrevivência Celular , Chlorocebus aethiops , Humanos , Ligantes , Modelos Biológicos , Ligação Proteica , Receptores de Superfície Celular/genética , Fator de Transcrição STAT6/genética , Fator de Transcrição STAT6/metabolismo , Vitamina A/metabolismoRESUMO
Sanguinarine (SAN) and chelerythrine (CHE) are known as major effective components in the quaternary benzo[c]phenanthridine isoquinoline alkaloids (QBA) fraction of Macleaya cordata (Willd) R. Br. but possess different biological activities. In this study, a method for the separation of SAN and CHE based on methyl acrylate-co-divinylbenzene (MA-co-DVB) macroporous adsorbents was established. The relationship between the polarities of the adsorbents and their adsorption-desorption behaviors towards SAN and CHE was investigated. The results showed that, among three selected commercial adsorbents and seven synthesized macroporous polymeric adsorbents with different MA content, the adsorbent No. 5 with 50% MA content provided the best separation power, and the two alkaloids were separated successfully in a gradient eluent process with 60% (v/v) ethanol aqueous and 80% ethanol aqueous contained 8% acetic acid. Dynamic adsorption and desorption tests had been performed in the column packed with the adsorbent No. 5 for optimizing the process parameters. Under the optimized conditions, the ratio of SAN and CHE transformed from 2:1 in the QBA fraction of M. cordata to 1:13 and 25:1 in the products obtained from the two-step gradient elution, and the recoveries of both SAN and CHE were nearly 90%.
Assuntos
Benzofenantridinas/isolamento & purificação , Fracionamento Químico/métodos , Isoquinolinas/isolamento & purificação , Papaveraceae/química , Estirenos/química , AdsorçãoRESUMO
Dichromate is known for severe health impairments to organisms. New and valid strategies have been developed to rapidly detect and efficiently remove this pollutant. Constructing stable luminescent metal-organic frameworks (MOFs) for dichromate recognition and removal from aqueous solution could provide a feasible resolution to this problem. Herein, a new luminescent Zr(IV)-MOF, Zr6O4(OH)7(H2O)3(BTBA)3 (BUT-39, BUT = Beijing University of Technology) was constructed through the reaction of a newly designed functionalized T-shaped ligand 4,4',4â³-(1 H-benzo[ d]imidazole-2,4,7-triyl)tribenzoic acid (H3BTBA) with zirconium salt. BUT-39 has a unique porous framework structure, in which Zr6 cluster acts as a rare low-symmetric 9-connected node and BTBA3- as a T-shaped 3-connected linker. As far as we know, this represents the first case of a (3,9)-connected Zr(IV)-MOF. BUT-39 could retain its framework integrity in boiling water, 2 M HCl aqueous solution, and pH 12 NaOH aqueous solution. Due to its good water stability and strong fluorescent emission, BUT-39 is then employed in fluorescence sensing for various ions in aqueous solution and shows good performance toward Cr2O72- selectively, at a low concentration and a short response time (<1 min). Simultaneously, it also exhibits excellent capacity to rapidly capture Cr2O72- (within 1 min) with a high uptake up to 1 mmol g-1. Taking advantage of its excellent stability, sensitive and selective sensing, as well as rapid and high adsorption, BUT-39 is expected to be useful in Cr2O72- detection in and removal from water.