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  1. Fulltext Controlled synthesis of iron oxyhydroxide (FeOOH) nanoparticles using secretory compounds from Chlorella vulgaris microalgae
    Ghanbariasad A, Taghizadeh SM, Show PL, Nomanbhay S, Berenjian A, Ghasemi Y, et al.
    Bioengineered, 2019 12;10(1):390-396.
    PMID: 31495263 DOI: 10.1080/21655979.2019.1661692
    FeOOH nanoparticles are commonly synthesized at very high temperature and pressure that makes the process energy consuming and non-economic. Recently, novel approaches were developed for the fabrication of these particles at room temperature. But, the main problem with these methods is that the prepared structures are aggregates of ultra-small nanoparticles where no intact separate nanoparticles are formed. In this study, for the first time, secretory compounds from Chlorella vulgaris cells were employed for the controlled synthesis of FeOOH nanoparticles at room atmosphere. Obtained particles were found to be goethite (α-FeO(OH)) crystals. Controlled synthesis of FeOOH nanoparticles resulted in uniform spherical nanoparticles ranging from 8 to 17 nm in diameter with 12.8 nm mean particle size. Fourier-transform infrared and elemental analyses were indicated that controlled synthesized nanoparticles have not functionalized with secretory compounds of C. vulgaris, and these compounds just played a controlling role over the synthesis reaction.
    Matched MeSH terms: Carbohydrates/chemistry; Ferric Compounds/chemistry*; Minerals/chemistry*; Plant Extracts/chemistry; Chlorella vulgaris/chemistry*; Nanoparticles/chemistry*; Green Chemistry Technology*; Iron Compounds/chemistry*
  2. Fulltext Antioxidant Activity Evaluation of FlexirubinType Pigment from Chryseobacterium artocarpi CECT 8497 and Related Docking Study
    Mogadem A, Almamary MA, Mahat NA, Jemon K, Ahmad WA, Ali I
    Molecules, 2021 Feb 12;26(4).
    PMID: 33673263 DOI: 10.3390/molecules26040979
    The current research is focused on studying the biological efficacy of flexirubin, a pigment extracted from Chryseobacterium artocarpi CECT 8497.Different methods such as DPPH, H2O2, NO•, O2•-, •OH, lipid peroxidation inhibition by FTC and TBA, ferric reducing and ferrous chelating activity were carried out to evaluate the antioxidant activity of flexirubin. Molecular docking was also carried out, seeking the molecular interactions of flexirubin and a standard antioxidant compound with SOD enzyme to figure out the possible flexirubin activity mechanism. The new findings revealed that the highest level of flexirubin exhibited similar antioxidant activity as that of the standard compound according to the H2O2, •OH, O2•-, FTC and TBA methods. On the other hand, flexirubin at the highest level has shown lower antioxidant activity than the positive control according to the DPPH and NO• and even much lower when measured by the FRAP method. Molecular docking showed that the interaction of flexirubin was in the binding cavity of the SOD enzyme and did not affect its metal-binding site. These results revealed that flexirubin has antioxidant properties and can be a useful therapeutic compound in preventing or treating free radical-related diseases.
    Matched MeSH terms: Antioxidants/chemistry*; Biphenyl Compounds/chemistry; Hydrogen Peroxide/chemistry; Nitric Oxide/chemistry; Picrates/chemistry; Pigments, Biological/chemistry*; Polyenes/chemistry*; Superoxide Dismutase/chemistry*; Chryseobacterium/chemistry
  3. Preparation and characterization of the encapsulated myrtle extract nanoliposome and nanoniosome without using cholesterol and toxic organic solvents: A comparative study
    Gorjian H, Raftani Amiri Z, Mohammadzadeh Milani J, Ghaffari Khaligh N
    Food Chem, 2021 Apr 16;342:128342.
    PMID: 33092927 DOI: 10.1016/j.foodchem.2020.128342
    Nanoliposome and nanoniosome formulations containing myrtle extract were prepared without using cholesterol and toxic organic solvents for the first time. The formulations had different concentrations of lecithin (5, 7, and 9% w/w) and Hydrophilic-Lipophilic Balance (HLB) values (6.76, 8.40, and 9.59). The physicochemical characterization results showed a nearly spherical shape for the prepared nanosamples. The particle sizes, zeta potentials and encapsulation efficiencies for the prepared nanoliposomes and nanoniosomes were at a range of 260-293 nm and 224-520 nm; -33.16 to - 31.16 mV and - 33.3 to - 10.36 mV; and 68-73% and 79-83%, respectively. The formulated nanoniosomes showed better stability during storage time. Besides, the encapsulation efficiency and in vitro release rate of myrtle extract could be controlled by adjusting the lecithin concentration and HLB value. The release of myrtle extract from nanovesicles showed a pH-responsive character. The FTIR analysis confirmed that the myrtle extract was encapsulated in nanovesicles physically.
    Matched MeSH terms: Cholesterol/chemistry; Liposomes/chemistry*; Plant Extracts/chemistry*; Solvents/chemistry; Myrtus/chemistry*; Nanostructures/chemistry*; Lecithins/chemistry; Green Chemistry Technology/methods*
  4. Fulltext A comparative study of conventional and supercritical fluid extraction methods for the recovery of secondary metabolites from Syzygium campanulatum Korth
    Memon AH, Hamil MS, Laghari M, Rithwan F, Zhari S, Saeed MA, et al.
    J Zhejiang Univ Sci B, 2016 Sep;17(9):683-982.
    PMID: 27604860 DOI: 10.1631/jzus.B1600019
    Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techniques and supercritical fluid extraction (SFE) techniques were performed to achieve a maximum recovery of two flavanones, chalcone, and two triterpenoids from S. campanulatum leaves. Furthermore, a Box-Behnken design was constructed for the SFE technique using pressure, temperature, and particle size as independent variables, and yields of crude extract, individual and total secondary metabolites as the dependent variables. In the CSE procedure, twenty extracts were produced using ten different solvents and three techniques (maceration, soxhletion, and reflux). An enriched extract of five secondary metabolites was collected using n-hexane:methanol (1:1) soxhletion. Using food-grade ethanol as a modifier, the SFE methods produced a higher recovery (25.5%‒84.9%) of selected secondary metabolites as compared to the CSE techniques (0.92%‒66.00%).
    Matched MeSH terms: Ethanol/chemistry; Methanol/chemistry; Hexanes/chemistry; Plant Extracts/chemistry; Solvents/chemistry; Terpenes/chemistry; Syzygium/chemistry*; Chalcones/chemistry; Flavones/chemistry
  5. Enhanced mannan-derived fermentable sugars of palm kernel cake by mannanase-catalyzed hydrolysis for production of biobutanol
    Shukor H, Abdeshahian P, Al-Shorgani NK, Hamid AA, Rahman NA, Kalil MS
    Bioresour Technol, 2016 Oct;218:257-64.
    PMID: 27372004 DOI: 10.1016/j.biortech.2016.06.084
    Catalytic depolymerization of mannan composition of palm kernel cake (PKC) by mannanase was optimized to enhance the release of mannan-derived monomeric sugars for further application in acetone-butanol-ethanol (ABE) fermentation. Efficiency of enzymatic hydrolysis of PKC was studied by evaluating effects of PKC concentration, mannanase loading, hydrolysis pH value, reaction temperature and hydrolysis time on production of fermentable sugars using one-way analysis of variance (ANOVA). The ANOVA results revealed that all factors studied had highly significant effects on total sugar liberated (P<0.01). The optimum conditions for PKC hydrolysis were 20% (w/v) PKC concentration, 5% (w/w) mannanase loading, hydrolysis pH 4.5, 45°C temperature and 72h hydrolysis time. Enzymatic experiments in optimum conditions revealed total fermentable sugars of 71.54±2.54g/L were produced including 67.47±2.51g/L mannose and 2.94±0.03g/L glucose. ABE fermentation of sugar hydrolysate by Clostridium saccharoperbutylacetonicum N1-4 resulted in 3.27±1.003g/L biobutanol.
    Matched MeSH terms: Acetone/chemistry; Ethanol/chemistry; Butanols/chemistry*; Carbohydrates/chemistry; Glucose/chemistry; Mannans/chemistry*; Mannose/chemistry; Arecaceae/chemistry*; beta-Mannosidase/chemistry*
  6. Dynamic Interfacial Adhesion through Cucurbit[n]uril Molecular Recognition
    Liu J, Tan CSY, Scherman OA
    Angew Chem Int Ed Engl, 2018 07 16;57(29):8854-8858.
    PMID: 29663607 DOI: 10.1002/anie.201800775
    Supramolecular building blocks, such as cucurbit[n]uril (CB[n])-based host-guest complexes, have been extensively studied at the nano- and microscale as adhesion promoters. Herein, we exploit a new class of CB[n]-threaded highly branched polyrotaxanes (HBP-CB[n]) as aqueous adhesives to macroscopically bond two wet surfaces, including biological tissue, through the formation of CB[8] heteroternary complexes. The dynamic nature of these complexes gives rise to adhesion with remarkable toughness, displaying recovery and reversible adhesion upon mechanical failure at the interface. Incorporation of functional guests, such as azobenzene moieties, allows for stimuli-activated on-demand adhesion/de-adhesion. Macroscopic interfacial adhesion through dynamic host-guest molecular recognition represents an innovative strategy for designing the next generation of functional interfaces, biomedical devices, tissue adhesives, and wound dressings.
    Matched MeSH terms: Azo Compounds/chemistry; Bridged Compounds/chemistry*; Cyclodextrins/chemistry*; Imidazoles/chemistry*; Tissue Adhesives/chemistry*; Water/chemistry; Hydrogels/chemistry; Poloxamer/chemistry*; Rotaxanes/chemistry*
  7. From formulation of acrylamide-based hydrogels to their optimization for drug release using response surface methodology
    Sabbagh F, Muhamad II, Nazari Z, Mobini P, Taraghdari SB
    Mater Sci Eng C Mater Biol Appl, 2018 Nov 01;92:20-25.
    PMID: 30184743 DOI: 10.1016/j.msec.2018.06.022
    This study conducted on the structure of modified acrylamide-based hydrogel by synthesizing the nano composites. The hydrogels employed in this study were provided through a combination of acrylamide monomers, sodium carboxymethyl cellulose (NaCMC) and magnesium oxide (MgO) nanoparticles by crosslinking polymerization. N,N,N',N'-tetramethylethylenediamine and ammonium persulfate as the initiator was applied in the structure of the polymer. Findings of the study considered the nano composites consisting of MgO have the highest swelling ratio compared to pure Aam hydrogels. Thus, MgO is an appropriate nanoparticle to be used in the nano composites. Response surface methodology (RSM) based on a central composite design (CCD Design) was applied to optimize the preparation variables of a hydrogel consisted of MgO, NaCMC. With the swelling ratio for acrylamide-based hydrogel as the response, the effects of two variables, i.e. MgO and NaCMC were investigated. The effects of pH, temperature, MgO, and NaCMC on the drug release were investigated using the CCD design. The predicted appropriate drug release conditions for the hydrogel at the highest rate of temperature (37.50 °C) and pH: 4.10, is at its highest value, while the lower drug release is at temperature 38 °C and pH 3.50. With the desired value of MgO (0.01 g) and amount of NaCMC (0.1 g).
    Matched MeSH terms: Acyclovir/chemistry; Carboxymethylcellulose Sodium/chemistry; Drug Carriers/chemistry*; Pharmaceutical Preparations/chemistry*; Magnesium Oxide/chemistry; Polymers/chemistry; Hydrogels/chemistry*; Acrylamide/chemistry; Nanoparticles/chemistry
  8. Fulltext Green synthesis of metallic nanoparticles using pectin as a reducing agent: a systematic review of the biological activities
    Devasvaran K, Lim V
    Pharm Biol, 2021 Dec;59(1):494-503.
    PMID: 33905665 DOI: 10.1080/13880209.2021.1910716
    CONTEXT: Pectin is a plant heteropolysaccharide that is biocompatible and biodegradable, enabling it to be an excellent reducing agent (green synthesis) for metallic nanoparticles (MNPs). Nevertheless, in the biological industry, pectin has been left behind in synthesising MNPs, for no known reason.

    OBJECTIVE: To systematically review the biological activities of pectin synthesised MNPs (Pe-MNPs).

    METHODS: The databases Springer Link, Scopus, ScienceDirect, Google Scholar, PubMed, Mendeley, and ResearchGate were systematically searched from the date of their inception until 10th February 2020. Pectin, green synthesis, metallic nanoparticles, reducing agent and biological activities were among the key terms searched. The data extraction was focussed on the biological activities of Pe-MNPs and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations for systematic reviews.

    RESULTS: A total of 15 studies outlined 7 biological activities of Pe-MNPs in the only three metals that have been explored, namely silver (Ag), gold (Au) and cerium oxide (CeO2). The activities reported from the in vitro and in vivo studies were antimicrobial (9 studies), anticancer (2 studies), drug carrier (3 studies), non-toxic (4 studies), antioxidant (2 studies), wound healing (1 study) and anti-inflammation (1 study).

    CONCLUSIONS: This systematic review demonstrates the current state of the art of Pe-MNPs biological activities, suggesting that Ag and Au have potent antibacterial and anticancer/chemotherapeutic drug carrier activity, respectively. Further in vitro, in vivo, and clinical research is crucial for a better understanding of the pharmacological potential of pectin synthesised MNPs.

    Matched MeSH terms: Cerium/chemistry; Drug Carriers/chemistry; Gold/chemistry; Pectins/chemistry*; Silver/chemistry; Reducing Agents/chemistry; Metal Nanoparticles/chemistry*; Green Chemistry Technology/methods*
  9. Removal of As(V) and Sb(V) in aqueous solution by Mg/Al-layered double hydroxide-incorporated polyethersulfone polymer beads (PES-LDH)
    Lee SH, Choi H, Kim KW
    Environ Geochem Health, 2018 Oct;40(5):2119-2129.
    PMID: 29536286 DOI: 10.1007/s10653-018-0087-y
    To develop a novel granular adsorbent to remove arsenic and antimony from water, calcined Mg/Al-layered double-hydroxide (CLDH)-incorporated polyethersulfone (PES) granular adsorbents (PES-LDH) were prepared using a core-shell method having 25% PES in an N,N-dimethylformamide solution. The PES-LDH displayed a spherical hollow shape having a rough surface and the average particle size of 1-2 mm. On the PES-LDH surface, nanosized CLDH (100-150 nm) was successfully immobilized by consolidation between PES and CLDH. The adsorption of Sb(V) by PES-LDH was found to be more favorable than for As(V), with the maximum adsorption capacity of As(V) and Sb(V) being 7.44 and 22.8 mg/g, respectively. The regeneration results indicated that a 0.5 M NaOH and 5 M NaCl mixed solution achieved an 80% regeneration efficiency in As(V) adsorption and desorption. However, the regeneration efficiency of Sb(V) gradually decreased due to its strong binding affinity, even though the PES-LDH showed much higher Sb(V) adsorption efficiency than As(V). This study suggested that PES-LDH could be a promising granular adsorbent for the remediation of As(V) and Sb(V) contained in wastewater.
    Matched MeSH terms: Antimony/chemistry*; Arsenic/chemistry*; Hydroxides/chemistry; Magnesium/chemistry; Polymers/chemistry; Sulfones/chemistry; Water/chemistry; Water Pollutants, Chemical/chemistry*; Waste Water/chemistry*
  10. Fulltext Chemical, Nutrient and Physicochemical Properties of Brown Seaweed, Sargassum polycystum C. Agardh (Phaeophyceae) Collected from Port Dickson, Peninsular Malaysia
    Nazarudin MF, Alias NH, Balakrishnan S, Wan Hasnan WNI, Noor Mazli NAI, Ahmad MI, et al.
    Molecules, 2021 Aug 27;26(17).
    PMID: 34500650 DOI: 10.3390/molecules26175216
    Recent increased interest in seaweed is motivated by attention generated in their bioactive components that have potential applications in the functional food and nutraceutical industries. In the present study, nutritional composition, metabolite profiles, phytochemical screening and physicochemical properties of freeze-dried brown seaweed, Sargassum polycystum were evaluated. Results showed that the S. polycystum had protein content of 8.65 ± 1.06%, lipid of 3.42 ± 0.01%, carbohydrate of 36.55 ± 1.09% and total dietary fibre content of 2.75 ± 0.58% on dry weight basis. The mineral content of S. polycystum including Na, K, Ca, Mg Fe, Se and Mn were 8876.45 ± 0.47, 1711.05 ± 0.07, 1079.75 ± 0.30, 213.85 ± 0.02, 277.6 ± 0.12, 4.70 ± 0.00 and 4.45 ± 0.00 mg 100/g DW, respectively. Total carotenoid, chlorophyll a and b content in S. polycystum were detected at 45.28 ± 1.77, 141.98 ± 1.18 and 111.29 µg/g respectively. The total amino acid content was 74.90 ± 1.45%. The study revealed various secondary metabolites and major constituents of S. polycystum fibre to include fucose, mannose, galactose, xylose and rhamnose. The metabolites extracted from the seaweeds comprised n-hexadecanoic acid, 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester, benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy- methyl ester, 1-dodecanol, 3,7,11-trimethyl-, which were the most abundant. The physicochemical properties of S. polycystum such as water-holding and swelling capacity were comparable to several commercial fibre-rich products. In conclusion, results of this study indicate that S. polycystum is a potential candidate as functional food sources for human consumption and its cultivation needs to be encouraged.
    Matched MeSH terms: Phaeophyta/chemistry*; Antioxidants/chemistry; Carotenoids/chemistry; Minerals/chemistry; Plant Extracts/chemistry; Seaweed/chemistry*; Vegetables/chemistry; Sargassum/chemistry*; Phytochemicals/chemistry*
  11. Antioxidants from tropical herbs
    Razab R, Abdul-Aziz A
    Nat Prod Commun, 2010 Mar;5(3):441-5.
    PMID: 20420325
    Plants that contain high amounts of polyphenolic compounds are potential candidates for natural antioxidant sources. Studies are on going in the search for new sources of antioxidants. Not much data are available on the antioxidant capacity of tropical herbs. With this in mind, 19 commonly consumed Malaysian herbs were analyzed for their polyphenolic content and antioxidant activities. A majority of these plants have never been studied before with regards to their polyphenolic content and antioxidant activities. The shoots of Anacardium occidentale, the shoots and fruits of Barringtonia racemosa, Pithecellobium jiringa and Parkia speciosa had high polyphenolic contents (> 150 microg gallic acid equivalents/mg dried plant) and antioxidant activities when measured using the ferric reducing antioxidant power (FRAP) (>1.2 mM) and Trolox equivalent antioxidant capacity (TEAC) assays (>2.4 mM). A strong correlation was observed between the two antioxidant assays (FRAP vs TEAC) implying that the plants could both scavenge free radicals and reduce oxidants. There was also a strong correlation between the antioxidant activities and polyphenolic content suggesting the observed antioxidant activities were contributed mainly by the polyphenolics in the plants.
    Matched MeSH terms: Antioxidants/chemistry*; Ferric Compounds/chemistry; Flavonoids/chemistry*; Fruit/chemistry; Phenols/chemistry*; Plants/chemistry*; Sulfonic Acids/chemistry; Free Radical Scavengers/chemistry; Oxidants/chemistry; Plant Shoots/chemistry; Reducing Agents/chemistry; Benzothiazoles/chemistry
  12. Fulltext Alpha-Mangostin-Rich Extracts from Mangosteen Pericarp: Optimization of Green Extraction Protocol and Evaluation of Biological Activity
    Ghasemzadeh A, Jaafar HZE, Baghdadi A, Tayebi-Meigooni A
    Molecules, 2018 Jul 25;23(8).
    PMID: 30044450 DOI: 10.3390/molecules23081852
    Since α-mangostin in mangosteen fruits was reported to be the main compound able to provide natural antioxidants, the microwave-assisted extraction process to obtain high-quality α-mangostin from mangosteen pericarp (Garcinia mangostana L.) was optimized using a central composite design and response surface methodology. The parameters examined included extraction time, microwave power, and solvent percentage. The antioxidant and antimicrobial activity of optimized and non-optimized extracts was evaluated. Ethyl acetate as a green solvent exhibited the highest concentration of α-mangostin, followed by dichloromethane, ethanol, and water. The highest α-mangostin concentration in mangosteen pericarp of 121.01 mg/g dry matter (DM) was predicted at 3.16 min, 189.20 W, and 72.40% (v/v). The verification of experimental results under these optimized conditions showed that the α-mangostin value for the mangosteen pericarp was 120.68 mg/g DM. The predicted models were successfully developed to extract α-mangostin from the mangosteen pericarp. No significant differences were observed between the predicted and the experimental α-mangostin values, indicating that the developed models are accurate. The analysis of the extracts for secondary metabolites showed that the total phenolic content (TPC) and total flavonoid content (TFC) increased significantly in the optimized extracts (OE) compared to the non-optimized extracts (NOE). Additionally, trans-ferulic acid and catechin were abundant among the compounds identified. In addition, the optimized extract of mangosteen pericarp with its higher α-mangostin and secondary metabolite concentrations exhibited higher antioxidant activities with half maximal inhibitory concentration (IC50) values of 20.64 µg/mL compared to those of the NOE (28.50 µg/mL). The OE exhibited the highest antibacterial activity, particularly against Gram-positive bacteria. In this study, the microwave-assisted extraction process of α-mangostin from mangosteen pericarp was successfully optimized, indicating the accuracy of the models developed, which will be usable in a larger-scale extraction process.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*; Antioxidants/chemistry*; Catechin/chemistry; Coumaric Acids/chemistry; Flavonoids/chemistry; Fruit/chemistry; Phenols/chemistry; Plant Extracts/chemistry*; Garcinia mangostana/chemistry*; Xanthones/chemistry*; Green Chemistry Technology/methods*
  13. Fulltext Characterization and in vitro drug release studies of a natural polysaccharide Terminalia catappa gum (Badam gum)
    Meka VS, Nali SR, Songa AS, Kolapalli VR
    AAPS PharmSciTech, 2012 Dec;13(4):1451-64.
    PMID: 23090110 DOI: 10.1208/s12249-012-9873-5
    The main objective of the present study is the physicochemical characterization of naturally available Terminalia catappa gum (Badam gum [BG]) as a novel pharmaceutical excipient and its suitability in the development of gastroretentive floating drug delivery systems (GRFDDS) to retard the drug for 12 h when the dosage form is exposed to gastrointestinal fluids in the gastric environment. As BG was being explored for the first time for its pharmaceutical application, physicochemical, microbiological, rheological, and stability studies were carried out on this gum. In the present investigation, the physicochemical properties, such as micromeritic, rheological, melting point, moisture content, pH, swelling index, water absorption, and volatile acidity, were evaluated. The gum was characterized by scanning electron microscopy, differential scanning calorimetry (DSC), powder X-ray diffraction studies (PXRD), and Fourier transform infrared spectroscopy (FTIR). Gastroretentive floating tablets of BG were prepared with the model drug propranolol HCl by direct compression methods. The prepared tablets were evaluated for all their physicochemical properties, in vitro buoyancy, in vitro drug release, and rate order kinetics. PBG 04 was selected as an optimized formulation based on its 12-h drug release and good buoyancy characteristics. The optimized formulation was characterized with FTIR, DSC, and PXRD studies, and no interaction between the drug and BG was found. Thus, the study confirmed that BG might be used in the gastroretentive drug delivery system as a release-retarding polymer.
    Matched MeSH terms: Chemistry, Pharmaceutical/methods; Excipients/chemistry*; Gastrointestinal Agents/chemistry; Gingiva/chemistry*; Polymers/chemistry; Polysaccharides/chemistry*; Powders/chemistry; Propranolol/chemistry; Tablets/chemistry; Water/chemistry; Terminalia/chemistry*
  14. Effect of Room Temperature Ionic Liquid on the Formation of the Complex Oxalate-Sodium Morin-5-Sulfonate-Aluminium(III): Application to the Fluorescence Determination of Oxalate Ion
    Nizar SA, Mohd Suah FB
    J Fluoresc, 2016 Jul;26(4):1167-71.
    PMID: 27286697 DOI: 10.1007/s10895-016-1845-9
    The effect of room temperature ionic liquid (RTIL) on the formation of the fluorescence ternary complex oxalate-sodium morin-5-sulfonate (NaMSA)-Aluminium(III) has been studied. In weakly acidic medium and in the presence of RTIL, 1-Butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6), total complex formation is achieved as compared with the formation of the binary complex of NaMSA-Aluminium(III). The fluorescence characteristics of the system allowed the establishment of a very sensitive method for the spectrofluorimetric determination of oxalate ion. The ternary complex formed its highest fluorescence signal at 513 nm and excitation at 420 nm. In these conditions, the method produces a detection limit of 0.57 ng mL(-1). The procedure has been satisfactorily applied to the determination of oxalate ion in a vegetal tissue (spinach leaves).
    Matched MeSH terms: Aluminum/chemistry*; Flavonoids/chemistry*; Oxalates/chemistry*; Sulfonic Acids/chemistry*; Ionic Liquids/chemistry*
  15. Characterization of un-plasticized and propylene carbonate plasticized carboxymethyl cellulose doped ammonium chloride solid biopolymer electrolytes
    Ahmad NH, Isa MIN
    Carbohydr Polym, 2016 Feb 10;137:426-432.
    PMID: 26686147 DOI: 10.1016/j.carbpol.2015.10.092
    Two solid biopolymer electrolytes (SBEs) systems of carboxymethyl cellulose doped ammonium chloride (CMC-AC) and propylene carbonate plasticized (CMC-AC-PC) were prepared via solution casting technique. The ionic conductivity of SBEs were analyzed using electrical impedance spectroscopy (EIS) in the frequency range of 50 Hz-1 MHz at ambient temperature (303K). The highest ionic conductivity of CMC-AC SBE is 1.43 × 10(-3)S/cm for 16 wt.% of AC while the highest conductivity of plasticized SBE system is 1.01 × 10(-2)S/cm when added with 8 wt.% of PC. TGA/DSC showed that the addition of PC had increased the decomposition temperature compared of CMC-AC SBE. Fourier transform infrared (FTIR) spectra showed the occurrence of complexation between the SBE components and it is proved successfully executed by Gaussian software. X-ray diffraction (XRD) indicated that amorphous nature of SBEs. It is believed that the PC is one of the most promising plasticizer to enhance the ionic conductivity and performance for SBE system.
    Matched MeSH terms: Ammonium Chloride/chemistry*; Biopolymers/chemistry*; Carboxymethylcellulose Sodium/chemistry*; Electrolytes/chemistry*; Propane/chemistry
  16. Synthesis and characterization of Co3O4 ultra-nanosheets and Co3O4 ultra-nanosheet-Ni(OH)2 as non-enzymatic electrochemical sensors for glucose detection
    Mahmoudian MR, Basirun WJ, Woi PM, Sookhakian M, Yousefi R, Ghadimi H, et al.
    Mater Sci Eng C Mater Biol Appl, 2016 Feb;59:500-508.
    PMID: 26652401 DOI: 10.1016/j.msec.2015.10.055
    The present study examines the synthesis of Co3O4 ultra-nanosheets (Co3O4 UNSs) and Co3O4 ultra-nanosheet-Ni(OH)2 (Co3O4 UNS-Ni(OH)2) via solvothermal process and their application as non-enzymatic electrochemical sensors for glucose detection. X-ray diffraction and transmission electron microscopy results confirmed the Co3O4 UNS deposition on Ni(OH)2 surface. The presence of Co3O4 UNSs on Ni (OH) 2 surface improved the sensitivity of glucose detection, from the increase of glucose oxidation peak current at the Co3O4 UNS-Ni(OH)2/glassy carbon electrode (current density: 2000μA·cm(-2)), compared to the Co3O4 UNSs. These results confirmed that Ni(OH)2 on glassy carbon electrode is a sensitive material for glucose detection, moreover the Co3O4 UNSs can increase the interaction and detection of glucose due to their high surface area. The estimated limit of detection (S/N=3) and limit of quantification (S/N=10) of the linear segment (5-40μM) are 1.08μM and 3.60μM respectively. The reproducibility experiments confirmed the feasibility of Co3O4 UNS-Ni(OH)2 for the quantitative detection of certain concentration ranges of glucose.
    Matched MeSH terms: Cobalt/chemistry*; Hydroxides/chemistry*; Nickel/chemistry*; Oxides/chemistry*; Nanostructures/chemistry*
  17. Fulltext A novel aqueous micellar two-phase system composed of surfactant and sorbitol for purification of pectinase enzyme from Psidium guajava and recycling phase components
    Amid M, Murshid FS, Manap MY, Hussin M
    Biomed Res Int, 2015;2015:815413.
    PMID: 25756051 DOI: 10.1155/2015/815413
    A novel aqueous two-phase system composed of a surfactant and sorbitol was employed for the first time to purify pectinase from Psidium guajava. The influences of different parameters, including the type and concentration of the surfactant and the concentration and composition of the surfactant/sorbitol ratio, on the partitioning behavior and recovery of pectinase were investigated. Moreover, the effects of system pH and the crude load on purification fold and the yield of purified pectinase were studied. The experimental results indicated that the pectinase was partitioned into surfactant-rich top phase, and the impurities were partitioned into the sorbitol-rich bottom phase with the novel method involving an ATPS composed of 26% (w/w) Triton X-100 and 23% (w/w) sorbitol at 54.2% of the TLL crude load of 20% (w/w) at pH 6.0. The enzyme was successfully recovered by this method with a high purification factor of 15.2 and a yield of 98.3%, whereas the phase components were also recovered and recycled at rates above 96%. This study demonstrated that this novel ATPS method can be used as an efficient and economical alternative to the traditional ATPS for the purification and recovery of the valuable enzyme.
    Matched MeSH terms: Polygalacturonase/chemistry*; Sorbitol/chemistry*; Surface-Active Agents/chemistry*; Water/chemistry*; Psidium/chemistry*
  18. Characterization and solubility study of norfloxacin-polyethylene glycol, polyvinylpyrrolidone and carbopol 974p solid dispersions
    Gorajana A, Kit WW, Dua K
    Recent Pat Drug Deliv Formul, 2015;9(2):167-82.
    PMID: 25714525
    OBJECTIVE: Norfloxacin has a low aqueous solubility which leads to poor dissolution. Keeping this fact in mind the purpose of the present study is to formulate and evaluate norfloxacin solid dispersion.

    METHODS: Solid dispersions were prepared using hydrophilic carriers like polyethylene glycol (PEG) 4000, polyvinylpyrrolidone (PVP) k30 and carbopol 974pNF (CP) in various ratios using solvent evaporation technique. These formulations were evaluated using solubility studies, dissolution studies; Fourier transmitted infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetery (DSC). The influence of polymer type and drug to polymer ratio on the solubility and dissolution rate of norfloxacin was also evaluated.

    RESULTS: FTIR analysis showed no interaction of all three polymers with norfloxacin. The results from XRD and DSC analyses of the solid dispersion preparations showed that norfloxacin existsin its amorphous form. Among the Norfloxacin: PEG solid dispersions, Norfloxacin: PEG 1:14 ratio showed the highest dissolution rate at pH 6.8. For norfloxacin: PVP solid dispersions, norfloxacin: PVP 1:10 ratio showed the highest dissolution rate at pH 6.8. For Norfloxacin: CP solid dispersions, norfloxacin: P 1:2 ratio showed the highest dissolution rate at pH 6.8.

    CONCLUSION: The solid dispersion of norfloxacin with polyethylene glycol (PEG) 4000, polyvinylpyrrolidone (PVP) k30 and carbopol 974p NF (CP), lends an ample credence for better therapeutic efficacy.

    Matched MeSH terms: Acrylates/chemistry*; Chemistry, Pharmaceutical; Norfloxacin/chemistry*; Polyethylene Glycols/chemistry*; Povidone/chemistry*
  19. A review: potential usage of cellulose nanofibers (CNF) for enzyme immobilization via covalent interactions
    Sulaiman S, Mokhtar MN, Naim MN, Baharuddin AS, Sulaiman A
    Appl Biochem Biotechnol, 2015 Feb;175(4):1817-42.
    PMID: 25427594 DOI: 10.1007/s12010-014-1417-x
    Nanobiocatalysis is a new frontier of emerging nanosized material support in enzyme immobilization application. This paper is about a comprehensive review on cellulose nanofibers (CNF), including their structure, surface modification, chemical coupling for enzyme immobilization, and potential applications. The CNF surface consists of mainly -OH functional group that can be directly interacted weakly with enzyme, and its binding can be improved by surface modification and interaction of chemical coupling that forms a strong and stable covalent immobilization of enzyme. The knowledge of covalent interaction for enzyme immobilization is important to provide more efficient interaction between CNF support and enzyme molecule. Enzyme immobilization onto CNF is having potential for improving enzymatic performance and production yield, as well as contributing toward green technology and sustainable sources.
    Matched MeSH terms: Cellulose/chemistry*; Cross-Linking Reagents/chemistry; Enzymes, Immobilized/chemistry*; Green Chemistry Technology; Nanofibers/chemistry*
  20. Processing and analysis of chitosan nanocomposites reinforced with chitin whiskers and tannic acid as a crosslinker
    Rubentheren V, Ward TA, Chee CY, Tang CK
    Carbohydr Polym, 2015 Jan 22;115:379-87.
    PMID: 25439908 DOI: 10.1016/j.carbpol.2014.09.007
    Chitosan film reinforced with nano-sized chitin whiskers and crosslinked using tannic acid was synthesized by the casting-vaporation method. The mechanical and physicochemical properties of several film samples (consisting of different ratio of chitin and tannic acid) were compared with neat chitosan. Tensile tests show that the addition of chitin improves the nanocomposite films mechanical properties up to 137% compared to neat chitosan, but this is slightly degraded when tannic acid is introduced. However, tannic acid and chitin whisker content greatly reduced moisture content by 294% and water solubility by 13%. Transmission electron microscopy (TEM) and Fourier-transform-infrared spectroscopy (FTIR) were used to investigate the morphology and molecular interaction of film. X-ray diffraction results indicated that the samples with chitin whiskers had a more rigid structure. The addition of tannic acid changed the structure into an anhydrous crystalline conformation when compared to neat chitosan film.
    Matched MeSH terms: Chitin/chemistry*; Tannins/chemistry*; Water/chemistry; Chitosan/chemistry*; Nanocomposites/chemistry*
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