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1.
Int J Mol Sci ; 24(19)2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37834192

RESUMO

Pyridoxylidene-aminoguanidine (PLAG) and its transition metal complexes are biologically active compounds with interesting properties. In this contribution, three new metal-PLAG complexes, Zn(PLAG)(SO4)(H2O)].∙H2O (Zn-PLAG), [Co(PLAG)2]SO4∙2H2O (Co-PLAG), and [Fe(PLAG)2]SO4∙2H2O) (Fe-PLAG), were synthetized and characterized by the X-ray crystallography. The intermolecular interactions governing the stability of crystal structure were compared to those of Cu(PLAG)(NCS)2 (Cu-PLAG) within Hirshfeld surface analysis. The structures were optimized at B3LYP/6-31+G(d,p)(H,C,N,O,S)/LanL2DZ (Fe,Co,Zn,Cu), and stability was assessed through Natural Bond Orbital Theory and Quantum Theory of Atoms in Molecules. Special emphasis was put on investigating the ligand's stability and reactivity. The binding of these compounds to Bovine and Human serum albumin was investigated by spectrofluorometric titration. The importance of complex geometry and various ligands for protein binding was shown. These results were complemented by the molecular docking study to elucidate the most important interactions. The thermodynamic parameters of the binding process were determined. The binding to DNA, as one of the main pathways in the cell death cycle, was analyzed by molecular docking. The cytotoxicity was determined towards HCT116, A375, MCF-7, and A2780 cell lines. The most active compound was Cu-PLAG due to the presence of PLAG and two thiocyanate ligands.


Assuntos
Complexos de Coordenação , Neoplasias Ovarianas , Feminino , Animais , Bovinos , Humanos , Ligação Proteica , Linhagem Celular Tumoral , Simulação de Acoplamento Molecular , Metais , DNA/química , Complexos de Coordenação/química , Zinco/química , Ligantes , Cobre/química
2.
Artigo em Inglês | MEDLINE | ID: mdl-37294491

RESUMO

Since the release of antibiotics as emerging contaminants into the environmental water can cause severe difficulties for human health, their removal from the water is necessary. In this regard, a novel environmentally friendly adsorbent was developed based on green sporopollenin, which was magnetized and modified with magnesium oxide nanoparticles to produce MSP@MgO nanocomposite. The newly developed adsorbent was applied to remove tetracycline antibiotic (TC) from aqueous media. The surface morphology of the MSP@MgO nanocomposite was characterized using FTIR, XRD, EDX, and SEM techniques. The effective parameters of the removal process were studied, and it was confirmed that the chemical structure of TC was highly affected by changes in pH solution due to different pKa; therefore, the results showed that pH 5 was the optimum. Also, the maximum sorption capacity of MSP@MgO for TC for adsorption was obtained at 109.89 mg.g-1. In addition, the adsorption models were investigated, and the process was fitted with the Langmuir model. Thermodynamic parameters showed that the process was spontaneous (ΔG < 0), endothermic (ΔH > 0) and the adsorption mechanism was following the physisorption mechanism at room temperature.

3.
Polymers (Basel) ; 15(4)2023 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-36850313

RESUMO

In this work, pectin biopolymers were functionalized with dichloride (5,10,15,20-tetraphenylporphyrinato) antimony [Sb(TPP)Cl2] at various compositions (0.5%, 1%, and 2%). The prepared compounds were characterized with several analytical methods, including X-ray fluorescence (XRF) spectrometry, Fourier-transform infrared spectroscopy (FT-IR), electrospray ionization mass spectrometry (EIS), scanning electron microscope (SEM), X-ray diffraction (XRD), and thermogravimetric-differential thermal (TGA/DTG) analysis. The XRF technique evidenced the presence of Sb metal in the composite beads. FT-IR suggested that the interaction between pectin and the [Sb(TPP)Cl2] complex was assured by inter- and intramolecular C-H⋯O, C-H⋯Cl hydrogen bonds and weak C-H⋯Cg π interactions (Cg is the centroid of the pyrrole and phenyl rings). The morphological features of the prepared polymeric beads were affected by the addition of [Sb(TPP)Cl2] particles, and the surface became rough. The thermal residual mass for the composite beads (29%) was more important than that of plain beads (23%), which confirmed the presence of inorganic matter in the modified polymeric beads. At 20 °C, the highest adsorption amounts of methylene blue were 39 mg/g and 68 mg/g for unmodified pectin and pectin-[Sb(TPP)Cl2] beads, respectively. The adsorption mechanism correlated well with the kinetic equation of the second order and the isotherm of Freundlich. The prepared polymeric beads were characterized as moderate-to-good adsorbents. The calculated thermodynamic parameters demonstrated an exothermic and thermodynamically nonspontaneous mechanism.

4.
Molecules ; 28(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36838692

RESUMO

With the increasing demand for wastewater treatment and multidrug resistance among pathogens, it was necessary to develop an efficient catalyst with enhanced photocatalytic and antibacterial applications. The present study proposes a facile and green strategy for synthesizing zinc oxide (ZnO) decorated nickel (Ni) nanomaterials. The synthesized Ni/ZnO nanocomposite displays a high crystallinity and spherical morphology, which was systematically characterized by XRD, SEM, FT-IR, UV-visible spectroscopy, EDX, HRTEM, and XPS techniques. In addition, the bacteriological tests indicated that Ni/ZnO nanocomposite exhibits potent antibacterial activity against human pathogens, i.e., Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli). The inhibition zone observed in light and dark conditions for E. coli was 16 (±0.3) mm and 8 (±0.4) mm, respectively, which confirms the high efficacy of the nanocomposite in the presence of light compared to dark conditions. The detailed inhibition mechanism of said bacterium and damage were also studied through fluorescence spectroscopy and SEM analysis, respectively. Evaluation of antioxidant activity based on free radical scavenging activity revealed that the Ni/ZnO nanocomposite effectively scavenges DPPH. In the photocatalytic performance, the Ni/ZnO nanocomposite exhibited a remarkable degradation ability under the optimized condition, which was attributed to their controllable size, high surface area, and exceptional morphology. Good selectivity, high photodegradation, and antibacterial activities and satisfactory hemolytic behavior of the as-prepared nanocomposite make them able to become a potential candidate for superior biological performance and environmental remediation.


Assuntos
Nanocompostos , Óxido de Zinco , Humanos , Antioxidantes/farmacologia , Óxido de Zinco/química , Espectroscopia de Infravermelho com Transformada de Fourier , Níquel/farmacologia , Escherichia coli , Staphylococcus aureus , Biomimética , Antibacterianos/farmacologia , Nanocompostos/química , Catálise
5.
J Contam Hydrol ; 253: 104122, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36563652

RESUMO

Groundwater resources are alarmingly depleting due to over-exploitation and significant climate changes over time. Therefore, demarcation of groundwater potential zones is essential for addressing the needs of various industries in semi-arid area. Depleting groundwater resources, topography, aquifer features and climatic factors make it necessary to demarcate ground water potential zones in semiarid region of Rajasthan. The Analytical Hierarchy Process (AHP), Geographic Information System (GIS), and Multi Influence Factor (MIF) were used to determine the groundwater potential zones (GWPZs) in the semi-arid region of Jaipur, located in western Rajasthan. In present study, ten influential factors were employed i.e., geomorphology, land use/land cover (LULC), drainage density, rainfall, topographic wetness index (TWI), soil texture, slope, roughness, topographic position index (TPI) and curvature. In AHP technique, the pairwise comparison matrix was generated, and weightages were given to each thematic layer while for MIF, a proposed score for each layer was computed from the aggregate weight of major and minor effects. The GWPZ map generated by AHP technique was categorised into three parts: high, moderate and poor potential zones, covering 13%, 50.7% and 36.3% of the district. While, the GWPZ map produced with the MIF technique was also divided into the same poor, moderate, and high categories, encompassing 35.3, 44.1, and 20.6% of the district, respectively. The results of AHP and MIF techniques were then cross-validated with well depth data obtained from CGWB report, 2019-20. The receiver operating characteristics (ROC) were plotted and the findings shows that the Area under the Curve (AUC) was 79% and 76% for AHP and MIF, respectively which is considered as moderate to high in predictive precision. The study would be helpful in locating drilling sites for groundwater exploration and developing sustainable groundwater and land use policies.


Assuntos
Processo de Hierarquia Analítica , Água Subterrânea , Índia , Monitoramento Ambiental/métodos , Sistemas de Informação Geográfica
6.
Bioengineering (Basel) ; 9(11)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36354544

RESUMO

Brucella suis, one of the causative agents of brucellosis, is Gram-negative intracellular bacteria that may be found all over the globe and it is a significant facultative zoonotic pathogen found in livestock. It may adapt to a phagocytic environment, reproduce, and develop resistance to harmful environments inside host cells, which is a crucial part of the Brucella life cycle making it a worldwide menace. The molecular underpinnings of Brucella pathogenicity have been substantially elucidated due to comprehensive methods such as proteomics. Therefore, we aim to explore the complete Brucella suis proteome to prioritize the novel proteins as drug targets via subtractive proteo-genomics analysis, an effort to conjecture the existence of distinct pathways in the development of brucellosis. Consequently, 38 unique metabolic pathways having 503 proteins were observed while among these 503 proteins, the non-homologs (n = 421), essential (n = 350), drug-like (n = 114), virulence (n = 45), resistance (n = 42), and unique to pathogen proteins were retrieved from Brucella suis. The applied subsequent hierarchical shortlisting resulted in a protein, i.e., isocitrate lyase, that may act as potential drug target, which was finalized after the extensive literature survey. The interacting partners for these shortlisted drug targets were identified through the STRING database. Moreover, structure-based studies were also performed on isocitrate lyase to further analyze its function. For that purpose, ~18,000 ZINC compounds were screened to identify new potent drug candidates against isocitrate lyase for brucellosis. It resulted in the shortlisting of six compounds, i.e., ZINC95543764, ZINC02688148, ZINC20115475, ZINC04232055, ZINC04231816, and ZINC04259566 that potentially inhibit isocitrate lyase. However, the ADMET profiling showed that all compounds fulfill ADMET properties except for ZINC20115475 showing positive Ames activity; whereas, ZINC02688148, ZINC04259566, ZINC04232055, and ZINC04231816 showed hepatoxicity while all compounds were observed to have no skin sensitization. In light of these parameters, we recommend ZINC95543764 compound for further experimental studies. According to the present research, which uses subtractive genomics, proteins that might serve as therapeutic targets and potential lead options for eradicating brucellosis have been narrowed down.

7.
Materials (Basel) ; 15(15)2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35897550

RESUMO

Cassava is a type of crop popular in Asian countries. It can be easily cultivated and grows to a mature plant in 9 months. Considering its availability, this work studied activated carbon based on cassava stem. Ofloxacin was chosen as the adsorbate, simulating the wastewater from the pharmaceutical industry. Cassava stem was ground into particles and heated to the activated state, 787 °C. The cassava-stem-activated carbon was further treated with the surface modifier, namely sodium hydroxide and zinc chloride, to study the improvement in ofloxacin adsorption. Prepared adsorbents were characterised using the SEM, FT-IR, XRD, DSC and TGA methods before being evaluated through batch adsorption, thermodynamic, and kinetic studies. The surface area analysis indicates that treatment of the activated carbon with NaOH and ZnCl2 increases the surface area due to the removal of organic content by the chemicals. Better ofloxacin adsorption of all activated carbon samples can be obtained with solutions at pH 8. An endothermic reaction was predicted, shown by higher ofloxacin adsorption at a higher temperature, supported by a positive value of ΔH° in the thermodynamic studies. The negative values of ΔG° revealed that adsorptions were spontaneous. The higher R2 values indicate that the adsorption process follows the pseudo-second-order equation of kinetic study. The maximum adsorption capacities are 42.37, 62.11, 62.89 and 58.82 mg/g for raw cassava stem (RC), cassava-stem-activated carbon (AC), NaOH-modified cassava-stem-activated carbon (NAC), and ZnCl2 modified cassava-stem-activated carbon (ZAC). The adsorption capacity is good compared to previous works by other researchers, making it a possible alternative material for the pharmaceutical industry's wastewater treatment.

8.
Endocr Pract ; 27(2): 83-89, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33554871

RESUMO

OBJECTIVE: To study the adrenocortical response to an acute coronavirus disease-2019 (COVID-19) infection. METHODS: Morning plasma cortisol, adrenocorticotropic hormone (ACTH), and dehydroepiandrosterone sulfate levels were measured in 28 consecutive patients with COVID-19 (16 men, 12 women, median age 45.5 years, range 25-69 years) on day 1 to 2 of hospital admission. These tests were repeated twice in 20 patients and thrice in 15 patients on different days. The hormone levels were correlated with severity of the disease. RESULTS: The median morning cortisol level was 196 (31-587) nmol/L. It was <100 nmol/L in 8 patients (28.6%), <200 nmol/L in 14 patients (50%), and <300 nmol/L in 18 patients (64.3%). The corresponding ACTH values had a median of 18.5 ng/L (range 4-38 ng/L), and the ACTH level was <10 ng/L in 7 patients (26.9%), <20 ng/L in 17 patients (60.7%), and <30 ng/L in 23 patients (82.1%). The repeated testing on different days showed a similar pattern. Overall, if a cutoff level of <300 nmol/L is considered abnormal in the setting of acute disease, 9 patients (32%) had cortisol levels below this limit, regardless of whether the test was done only once (3 patients) or 3 times (6 patients). When the disease was more severe, the patients had lower cortisol and ACTH levels, suggesting a direct link between the COVID-19 infection and impaired glucocorticoid response. CONCLUSION: Unexpectedly, the adrenocortical response in patients with COVID-19 infection was impaired, and a significant percentage of the patients had plasma cortisol and ACTH levels consistent with central adrenal insufficiency.


Assuntos
COVID-19 , Sistema Hipotálamo-Hipofisário , Hormônio Adrenocorticotrópico , Adulto , Idoso , Feminino , Humanos , Hidrocortisona , Masculino , Pessoa de Meia-Idade , Sistema Hipófise-Suprarrenal , SARS-CoV-2
9.
Sci Rep ; 10(1): 650, 2020 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-31959766

RESUMO

Oil palm is an important crop for global vegetable oil production, and is widely grown in the humid tropical regions of Southeast Asia. Projected future climate change may well threaten palm oil production. However, oil palm plantations currently produce large amounts of unutilised biological waste. Oil palm stems - which comprise two-thirds of the waste - are especially relevant because they can contain high levels of non-structural carbohydrates (NSC) that can serve as feedstock for biorefineries. The NSC in stem are also considered a potent buffer to source-sink imbalances. In the present study, we monitored stem NSC levels and female reproductive growth. We then applied convergent cross mapping (CCM) to assess the causal relationship between the time-series. Mutual causal relationships between female reproductive growth and the stem NSC were detected, with the exception of a relationship between female reproductive organ growth and starch levels. The NSC levels were also influenced by long-term cumulative temperature, with the relationship showing a seven-month time lag. The dynamic between NSC levels and long-term cumulative rainfall showed a shorter time lag. The lower temperatures and higher cumulative rainfall observed from October to December identify this as a period with maximum stem NSC stocks.


Assuntos
Arecaceae/crescimento & desenvolvimento , Arecaceae/metabolismo , Metabolismo dos Carboidratos , Mudança Climática , Óleo de Palmeira , Reprodução , Amido/metabolismo , Chuva , Estações do Ano , Temperatura
10.
Micromachines (Basel) ; 11(1)2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31861476

RESUMO

With the fast development of the fifth-generation cellular network technology (5G), the future sensors and microelectromechanical systems (MEMS)/nanoelectromechanical systems (NEMS) are presenting a more and more critical role to provide information in our daily life. This review paper introduces the development trends and perspectives of the future sensors and MEMS/NEMS. Starting from the issues of the MEMS fabrication, we introduced typical MEMS sensors for their applications in the Internet of Things (IoTs), such as MEMS physical sensor, MEMS acoustic sensor, and MEMS gas sensor. Toward the trends in intelligence and less power consumption, MEMS components including MEMS/NEMS switch, piezoelectric micromachined ultrasonic transducer (PMUT), and MEMS energy harvesting were investigated to assist the future sensors, such as event-based or almost zero-power. Furthermore, MEMS rigid substrate toward NEMS flexible-based for flexibility and interface was discussed as another important development trend for next-generation wearable or multi-functional sensors. Around the issues about the big data and human-machine realization for human beings' manipulation, artificial intelligence (AI) and virtual reality (VR) technologies were finally realized using sensor nodes and its wave identification as future trends for various scenarios.

11.
Int J Biol Macromol ; 132: 1304-1317, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30922916

RESUMO

The utilization of renewable and functional group enriched nano-lignin as bio-additve in fabricating composite has become the focus of attention worldwide. Herein, lignin nanoparticles in the form of hollow spheres with the diameter of the order of 138 ±â€¯39 nm were directly prepared from agro-industrial waste (palm kernel shell) using recyclable tetrahydrofuran in an acidified aqueous system without any chemical modification steps. We then fabricated a new chitosan/nano-lignin composite material as highly efficient sorbent, as demonstrated by efficient removal (~83%) of methylene blue (MB) dye under natural pH conditions. The adsorption process obeyed pseudo-second-order kinetics and adequate fitting of the adsorption data using Langmuir model suggested a monolayer adsorption with a maximum adsorption capacity of 74.07 mg g-1. Moreover, thermodynamic study of the system revealed spontaneous and endothermic nature of the sorption process. Further studies revealed that chitosan composite with nano-lignin showed better performance in dye decontamination compared to native chitosan and chitosan/bulk lignin composite. This could essentially be attributed to synergistic effects of size particularity (nano-effect) and incorporated functionalities due to lignin nanoparticles. Recyclability study performed in four repeated adsorption/regeneration cycles revealed recyclable nature of as-prepared composite, whilst adsorption experiments using spiked real water samples indicated recoveries as high as 89%. Based on this study, as-prepared bio-nanocomposite may thus be considered as an efficient and reusable adsorptive platform for the decontamination of water supplies.


Assuntos
Quitosana/química , Corantes/química , Corantes/isolamento & purificação , Lignina/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Água/química , Adsorção , Concentração de Íons de Hidrogênio , Resíduos Industriais , Azul de Metileno/química , Azul de Metileno/isolamento & purificação , Nanocompostos/química , Soluções , Termodinâmica , Purificação da Água
12.
Chem Cent J ; 12(1): 128, 2018 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-30515636

RESUMO

Coumarins are the phytochemicals, which belong to the family of benzopyrone, that display interesting pharmacological properties. Several natural, synthetic and semisynthetic coumarin derivatives have been discovered in decades for their applicability as lead structures as drugs. Coumarin based conjugates have been described as potential AChE, BuChE, MAO and ß-amyloid inhibitors. Therefore, the objective of this review is to focus on the construction of these pharmacologically important coumarin analogues with anti-Alzheimer's activities, highlight their docking studies and structure-activity relationships based on their substitution pattern with respect to the selected positions on the chromen ring by emphasising on the research reports conducted in between year 1968 to 2017.

13.
Chem Cent J ; 12(1): 69, 2018 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-29896651

RESUMO

A series of novel 4-thiazolidinone inhibitors SKYa-SKYg, containing coumarin as a core structure were synthesized via facile and efficient method. The structures of the synthesized compounds were established by extensive spectroscopic studies (FT IR, 1D NMR, 2D NMR, LC-MS) and elemental analysis. All the synthesized hybrids were further evaluated for their potential as anti-tubercular agents against Mycobacterium tuberculosis H37Rv ATCC 25618, and anti-bacterial agents against Escherichia coli, Enterobacter aerogenes, Salmonella typhi, Streptococcus pneumoniae and Staphylococcus aureus. Interestingly, the hybrids displayed potent bioactivity. However, compounds SKYc, SKYd, and SKYe appeared to be more effective against the tested bacterial strains, among which compound SKYb showed the highest inhibition against all the bacterial strains ranging from 41 to 165 µg/mL, as compared to the standards, streptomycin, kanamycin and vancomycin. Moreover, derivative SKYa was found to be the strongest against M. tuberculosis (83 µg/mL). Additionally, the anti-dengue potential of the coumarin hybrids as two-component NS2B/NS3 DENV flavivirus serine protease inhibitors was calculated using computational molecular docking approach, with reference to the standards 4-hydroxypanduratin, panduratin and ethyl 3-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy)propanoate with DS of - 3.379, - 3.189 and - 3.381, respectively. The docking results revealed that the synthesized hybrids exhibited potent anti-dengue activity among which compounds SKYf, SKYd, SKYc and SKYe were found to be the best ones with docking scores of - 4.014, - 3.964, - 3.905 and - 3.889. In summary, we discovered 4-thiazolidinone coumarin derivatives as a new scaffold that may eventually yield useful compounds in the treatment of bacterial and viral infections.

14.
Enzyme Microb Technol ; 111: 21-28, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29421033

RESUMO

Oil palm trunk (OPT) is one of the most promising lignocellulosic bioresources. To develop effective biodegradation, thermophilic, anaerobic microorganisms were screened from bovine manure compost using fibrillated OPT (f-OPT) pretreated by wet disk milling as the substrate. One thermophilic, anaerobic bacterium, strain CL-2, whose 16S rDNA gene has 98.6% sequence identity with that of Caldicoprobacter faecale DSM 20678T, exhibited high degradation activity (32.7% reduction in total dry solids of f-OPT). Strain CL-2 did not use cellulose as a carbon source, but used hemicelluloses such as xylan, arabinoxylan, starch and pectin at 70 °C. Phylogenetic and morphologic analyses and the polysaccharide use suggest that CL-2 may be classified as a novel species of Caldicoprobacter, named Caldicoprobacter sp. CL-2. To characterize enzymatic activities of CL-2, extracellular enzymes were prepared from culture broth using beechwood xylan as the carbon source. The extracellular enzymes showed high xylanase activity, but low cellulase activity, suggesting that f-OPT degradation may depend on xylanase activity. To understand the xylanase system of CL-2, a major xylanase was cloned and characterized. The xylanase (CalXyn11A) had a modular structure consisting of a glycoside hydrolase (GH) family-11 domain and a family 36 carbohydrate-binding module. CalXyn11A did not show f-OPT degradation activity, but a strong synergistic effect was observed when CalXyn11A was added to the extracellular enzyme preparation. These results indicate that, rather than working alone, CalXyn11A has an important role in enhancing total lignocellulose degradation activity by cooperation with other GHs.


Assuntos
Arecaceae/química , Proteínas de Bactérias/metabolismo , Clostridiales/enzimologia , Clostridiales/isolamento & purificação , Endo-1,4-beta-Xilanases/metabolismo , Anaerobiose , Animais , Arecaceae/ultraestrutura , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Biodegradação Ambiental , Biocombustíveis , Biomassa , Biotransformação , Bovinos/microbiologia , Clostridiales/genética , Compostagem , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/isolamento & purificação , Genes Bacterianos , Cinética , Lignina , Filogenia , Especificidade por Substrato
15.
Appl Biochem Biotechnol ; 183(1): 412-425, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28361245

RESUMO

The availability of fermentable sugars in high concentrations in the sap of felled oil palm trunks and the thermophilic nature of the recently isolated Bacillus coagulans strain 191 were exploited for lactic acid production under non-sterile conditions. Screening indicated that strain 191 was active toward most sugars including sucrose, which is a major component of sap. Strain 191 catalyzed a moderate conversion of sap sugars to lactic acid (53%) with a productivity of 1.56 g/L/h. Pretreatment of oil palm sap (OPS) using alkaline precipitation improved the sugar fermentability, providing a lactic acid yield of 92% and productivity of 2.64 g/L/h. To better characterize potential inhibitors in the sap, phenolic, organic, and mineral compounds were analyzed using non-treated sap and saps treated with activated charcoal and alkaline precipitation. Phthalic acid, 3,4-dimethoxybenzoic acid, aconitic acid, syringic acid, and ferulic acid were reduced in the sap after treatment. High concentrations of Mg, P, K, and Ca were also precipitated by the alkaline treatment. These results suggest that elimination of excess phenolic and mineral compounds in OPS can improve the fermentation yield. OPS, a non-food resource that is readily available in bulk quantities from plantation sites, is a promising source for lactic acid production.


Assuntos
Arecaceae/química , Bacillus/crescimento & desenvolvimento , Ácido Láctico/biossíntese , Sacarose/química , Sacarose/metabolismo
16.
Carbohydr Polym ; 156: 409-416, 2017 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-27842840

RESUMO

Cellulose nanocrystals were isolated from oil palm trunk by total chlorine free method. The samples were either water pre-hydrolyzed or non-water pre-hydrolyzed, subjected to soda pulping, acidified and ozone bleached. Cellulose and cellulose nanocrystal (CNC) physical, chemical, thermal properties, and crystallinity index were investigated by composition analysis, scanning electron microscopy, transmission electron microscopy, fourier transform infrared, thermogravimetric analysis and X-ray diffraction. Water pre-hydrolysis reduced lignin (<0.5%) and increased holocellulose (99.6%) of ozone-bleached cellulose. Water pre-hydrolyzed cellulose exhibited surface fibrillation and peeling off after acid hydrolysis process compared to non-fibrillated of non-water pre-hydrolyzed cellulose. Water pre-hydrolysis improved final CNC crystallinity (up to 75%) compared to CNC without water pre-hydrolysis crystallinity (69%). Cellulose degradation was found to occur during ozone bleaching stage but CNC showed an increase in crystallinity after acid hydrolysis. Thus, oil palm trunk CNC can be potentially applied in pharmaceutical, food, medical and nanocomposites.


Assuntos
Arecaceae/química , Celulose/química , Celulose/isolamento & purificação , Nanopartículas/química , Caules de Planta/química , Hidrólise , Água/química
17.
Carbohydr Polym ; 134: 534-40, 2015 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-26428155

RESUMO

In this study cellulose nanocrystals were isolated through acid hydrolysis process from parenchyma and vascular bundle of oil palm trunk (Elaeis guineensis). The morphological properties of obtained cellulose nanocrystals were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The microscopy images showed smoother and cleaner surface of parenchyma cellulose nanocrystals when compared to vascular bundle cellulose nanocrystals. The TEM image shows a higher length and diameter for parenchyma cellulose nanocrystals compared to vascular bundle cellulose nanocrystals. The Fourier transform infrared (FTIR) spectra showed changes in functional groups after acid hydrolysis due to removal of lignin, hemicelluloses and other impurities in both type of cellulose nanocrystals. Crystallinity index of cellulose nanocrystals was observed higher for vascular bundle as compared to parenchyma. Thermogravimetric analysis (TGA) was performed to study the thermal stability of cellulose nanocrystals and it was observed higher for parenchyma cellulose nanocrystals compared to vascular bundle.


Assuntos
Arecaceae/química , Celulose/química , Celulose/isolamento & purificação , Nanopartículas , Arecaceae/citologia
18.
Carbohydr Polym ; 127: 202-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25965475

RESUMO

In this study cellulose nanocrystals were isolated from oil palm trunk (Elaeis guineensis) using acid hydrolysis method. The morphology and size of the nanocrystals were characterized using scanning electron microscopy and transmission electron microscopy. The results showed that the nanocrystals isolated from raw oil palm trunk (OPT) fibers and hot water treated OPT fibers had an average diameter of 7.67 nm and 7.97 nm and length of 397.03 nm and 361.70 nm, respectively. Fourier Transform Infrared spectroscopy indicated that lignin and hemicellulose contents decreased. It seems that lignin was completely removed from the samples during chemical treatment. Thermogravimetric analysis demonstrated that cellulose nanocrystals after acid hydrolysis had higher thermal stability compared to the raw and hot water treated OPT fibers. The X-ray diffraction analysis increased crystallinity of the samples due to chemical treatment. The crystalline nature of the isolated nanocrystals from raw and hot water treated OPT ranged from 68 to 70%.


Assuntos
Arecaceae/química , Celulose/química , Nanopartículas/química , Óleos de Plantas/química , Ácidos , Hidrólise , Caules de Planta/química
19.
Acta Crystallogr E Crystallogr Commun ; 71(Pt 1): o6-7, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25705509

RESUMO

In the title iso-quinoline-1,3,4-trione derivative, C18H9NO5, the five-membered ring of the indane fragment adopts an envelope conformation with the nitro-gen-substituted C atom being the flap. The planes of the indane benzene ring and the iso-quinoline-1,3,4-trione ring make a dihedral angle of 82.06 (6)°. In the crystal, mol-ecules are linked into chains extending along the bc plane via C-H⋯O hydrogen-bonding inter-actions, enclosing R 2 (2)(8) and R 2 (2)(10) loops. The chains are further connected by π-π stacking inter-ations, with centroid-to-centroid distances of 3.9050 (7) Å, forming layers parallel to the b axis.

20.
Asian Pac J Trop Med ; 7S1: S553-9, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25312183

RESUMO

OBJECTIVE: To evaluate antioxidant activities of seven medicinal plant species and their fractions, and to identify their phenolic compounds. METHODS: Two extractions were processed and further fractionated by column chromatography to evaluate the concentration that inhibit 50% of 2,2'-azinobis (3-ethylbenzothiazoline-6-suslfonic acid, 1,1-diphenyl-2-picryl-hydrazyl radicals, and their ferric reducing antioxidant power. The identification of the fractions of phenolic compounds was done by ultra performance liquid chromatography. RESULTS: The aqueous-acetone extracts of Feretia apodanthera and Ozoroa insignis exhibited the highest antioxidant potentials comparable to those of the standard quercetin. Their subsequently silica gel column fractionation showed three most active fractions from which the major constituents quercetin, myricetin, kampferol, rutin and isoquercetin were identified. CONCLUSIONS: These plant species have potent antioxidant profiles and polyphenol compounds that may help to manage with radical related disease and aging.

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