Displaying publications 1121 - 1140 of 10538 in total

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  1. Fulltext COSMO-RS Based Prediction for Alpha-Linolenic Acid (ALA) Extraction from Microalgae Biomass Using Room Temperature Ionic Liquids (RTILs)
    Rezaei Motlagh S, Harun R, Awang Biak DR, Hussain SA, Omar R, Elgharbawy AA
    Mar Drugs, 2020 Feb 12;18(2).
    PMID: 32059424 DOI: 10.3390/md18020108
    One of the essential fatty acids with therapeutic impacts on human health is known to be omega-3 polyunsaturated fatty acids (PUFA). More lately, ionic liquids (ILs) have received significant attention among scientists in overcoming the disadvantages of traditional solvents in biomass lipid extraction. However, the large pool of cations and anions possibly accessible will lead to a growing number of innovatively synthesized ILs. Nevertheless, the exhaustive measurement of all these systems is economically impractical. The conductive screening model for real solvents (COSMO-RS) is considered a precious approach with the availability of a few models to predict the characteristics of ILs. This work introduces the estimate of capacity values at infinite dilution for a range of ILs using COSMO-RS software as part of solid-liquid extraction. This favorable outcome presented that the capacity values of the IL molecules are extremely dependent on both anions and cations. Among the 352 combinations of cation/anion tested, short alkyl chain cations coupled with inorganic anions were found to be most efficient and therefore superior in the extraction method. Sulphate-, chloride-, and bromide-based ILs were found to have higher extraction capacities in contrast with the remainders, while propanoate revealed an extraordinary capacity when combined with ethyl-based cations. Eventually, the predicted results from COSMO-RS were validated through the experimentally calculated extraction yield of alpha-linolenic acid (ALA) compound from Nannochloropsis sp. microalgae. Three selected ILs namely [EMIM][Cl], [TMAm][Cl], and [EMPyrro][Br] were selected from COSMO-RS for empirical extraction purpose and the validation results pinpointed the good prediction capability of COSMO-RS.
    Matched MeSH terms: Anions/chemistry; Cations/chemistry; Ions/chemistry; alpha-Linolenic Acid/chemistry*; Ionic Liquids/chemistry*; Microalgae/chemistry*
  2. Fulltext A facile thermal-treatment route to synthesize ZnO nanosheets and effect of calcination temperature
    Al-Hada NM, Saion EB, Shaari AH, Kamarudin MA, Flaifel MH, Ahmad SH, et al.
    PLoS One, 2014;9(8):e103134.
    PMID: 25093752 DOI: 10.1371/journal.pone.0103134
    A facile thermal-treatment route was successfully used to synthesize ZnO nanosheets. Morphological, structural, and optical properties of obtained nanoparticles at different calcination temperatures were studied using various techniques. The FTIR, XRD, EDX, SEM and TEM images confirmed the formation of ZnO nanosheets through calcination in the temperature between 500 to 650 °C. The SEM images showed a morphological structure of ZnO nanosheets, which inclined to crumble at higher calcination temperatures. The XRD and FTIR spectra revealed that the samples were amorphous at 30 °C but transformed into a crystalline structure during calcination process. The average particle size and degree of crystallinity increased with increasing calcination temperature. The estimated average particle sizes from TEM images were about 23 and 38 nm for the lowest and highest calcination temperature i.e. 500 and 650 °C, respectively. The optical properties were determined by UV-Vis reflection spectrophotometer and showed a decrease in the band gap with increasing calcination temperature.
    Matched MeSH terms: Nitrates/chemistry; Povidone/chemistry; Water/chemistry; Zinc Oxide/chemistry*; Zinc Compounds/chemistry; Nanostructures/chemistry*
  3. Fulltext Hell's Gate globin I: an acid and thermostable bacterial hemoglobin resembling mammalian neuroglobin
    Teh AH, Saito JA, Baharuddin A, Tuckerman JR, Newhouse JS, Kanbe M, et al.
    FEBS Lett, 2011 Oct 20;585(20):3250-8.
    PMID: 21925500 DOI: 10.1016/j.febslet.2011.09.002
    Hell's Gate globin I (HGbI), a heme-containing protein structurally homologous to mammalian neuroglobins, has been identified from an acidophilic and thermophilic obligate methanotroph, Methylacidiphilum infernorum. HGbI has very high affinity for O(2) and shows barely detectable autoxidation in the pH range of 5.2-8.6 and temperature range of 25-50°C. Examination of the heme pocket by X-ray crystallography and molecular dynamics showed that conformational movements of Tyr29(B10) and Gln50(E7), as well as structural flexibility of the GH loop and H-helix, may play a role in modulating its ligand binding behavior. Bacterial HGbI's unique resistance to the sort of extreme acidity that would extract heme from any other hemoglobin makes it an ideal candidate for comparative structure-function studies of the expanding globin superfamily.
    Matched MeSH terms: Bacterial Proteins/chemistry*; Globins/chemistry; Gram-Negative Bacteria/chemistry*; Hemoglobins/chemistry*; Nerve Tissue Proteins/chemistry; Oxygen/chemistry
  4. Fulltext Impact of Storage Conditions on the Stability of Predominant Phenolic Constituents and Antioxidant Activity of Dried Piper betle Extracts
    Ali A, Chong CH, Mah SH, Abdullah LC, Choong TSY, Chua BL
    Molecules, 2018 Feb 23;23(2).
    PMID: 29473847 DOI: 10.3390/molecules23020484
    The phenolic constituents in Piper betle are well known for their antioxidant potential; however, current literature has very little information on their stability under the influence of storage factors. Present study evaluated the stability of total phenolic content (TPC) and antioxidant activity together with individual phenolic constituents (hydroxychavicol, eugenol, isoeugenol and allylpyrocatechol 3,4-diacetate) present in dried Piper betle's extract under different storage temperature of 5 and 25 °C with and without light for a period of six months. Both light and temperature significantly influenced TPC and its corresponding antioxidant activity over time. More than 95% TPC and antioxidant activity was retained at 5 °C in dark condition after 180 days of storage. Hydroxychavicol demonstrated the best stability with no degradation while eugenol and isoeugenol displayed moderate stability in low temperature (5 °C) and dark conditions. 4-allyl-1,2-diacetoxybenzene was the only compound that underwent complete degradation. A new compound, 2,4-di-tert-butylphenol, was detected after five weeks of storage only in the extracts exposed to light. Both zero-order and first-order kinetic models were adopted to describe the degradation kinetics of the extract's antioxidant activity. Zero-order displayed better fit with higher correlation coefficients (R² = 0.9046) and the half-life was determined as 62 days for the optimised storage conditions (5 °C in dark conditions).
    Matched MeSH terms: Antioxidants/chemistry*; Plant Extracts/chemistry*; Free Radical Scavengers/chemistry; Phenol/chemistry*; Piper betle/chemistry*; Phytochemicals/chemistry
  5. Fulltext Cellulose nanocrystals/ZnO as a bifunctional reinforcing nanocomposite for poly(vinyl alcohol)/chitosan blend films: fabrication, characterization and properties
    Azizi S, Ahmad MB, Ibrahim NA, Hussein MZ, Namvar F
    Int J Mol Sci, 2014 Jun 18;15(6):11040-53.
    PMID: 24945313 DOI: 10.3390/ijms150611040
    In this study, cellulose nanocrystals/zinc oxide (CNCs/ZnO) nanocomposites were dispersed as bifunctional nano-sized fillers into poly(vinyl alcohol) (PVA) and chitosan (Cs) blend by a solvent casting method to prepare PVA/Cs/CNCs/ZnO bio-nanocomposites films. The morphology, thermal, mechanical and UV-vis absorption properties, as well antimicrobial effects of the bio-nanocomposite films were investigated. It demonstrated that CNCs/ZnO were compatible with PVA/Cs and dispersed homogeneously in the polymer blend matrix. CNCs/ZnO improved tensile strength and modulus of PVA/Cs significantly. Tensile strength and modulus of bio-nanocomposite films increased from 55.0 to 153.2 MPa and from 395 to 932 MPa, respectively with increasing nano-sized filler amount from 0 to 5.0 wt %. The thermal stability of PVA/Cs was also enhanced at 1.0 wt % CNCs/ZnO loading. UV light can be efficiently absorbed by incorporating ZnO nanoparticles into a PVA/Cs matrix, signifying that these bio-nanocomposite films show good UV-shielding effects. Moreover, the biocomposites films showed antibacterial activity toward the bacterial species Salmonella choleraesuis and Staphylococcus aureus. The improved physical properties obtained by incorporating CNCs/ZnO can be useful in variety uses.
    Matched MeSH terms: Cellulose/chemistry*; Polyvinyl Alcohol/chemistry*; Zinc Oxide/chemistry*; Chitosan/chemistry*; Nanoparticles/chemistry*; Nanocomposites/chemistry*
  6. Fulltext Enhanced photoluminescence and Raman properties of Al-Doped ZnO nanostructures prepared using thermal chemical vapor deposition of methanol assisted with heated brass
    Thandavan TM, Gani SM, San Wong C, Md Nor R
    PLoS One, 2015;10(3):e0121756.
    PMID: 25756598 DOI: 10.1371/journal.pone.0121756
    Vapor phase transport (VPT) assisted by mixture of methanol and acetone via thermal evaporation of brass (CuZn) was used to prepare un-doped and Al-doped zinc oxide (ZnO) nanostructures (NSs). The structure and morphology were characterized by field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). Photoluminescence (PL) properties of un-doped and Al-doped ZnO showed significant changes in the optical properties providing evidence for several types of defects such as zinc interstitials (Zni), oxygen interstitials (Oi), zinc vacancy (Vzn), singly charged zinc vacancy (VZn-), oxygen vacancy (Vo), singly charged oxygen vacancy (Vo+) and oxygen anti-site defects (OZn) in the grown NSs. The Al-doped ZnO NSs have exhibited shifted PL peaks at near band edge (NBE) and red luminescence compared to the un-doped ZnO. The Raman scattering results provided evidence of Al doping into the ZnO NSs due to peak shift from 145 cm-1 to an anomalous peak at 138 cm-1. Presence of enhanced Raman signal at around 274 and 743 cm-1 further confirmed Al in ZnO NSs. The enhanced D and G band in all Al-doped ZnO NSs shows possible functionalization and doping process in ZnO NSs.
    Matched MeSH terms: Methanol/chemistry*; Copper/chemistry*; Silicon/chemistry; Zinc/chemistry*; Zinc Oxide/chemistry*; Nanostructures/chemistry*
  7. Fulltext Green biosynthesis and characterization of magnetic iron oxide (Fe₃O₄) nanoparticles using seaweed (Sargassum muticum) aqueous extract
    Mahdavi M, Namvar F, Ahmad MB, Mohamad R
    Molecules, 2013 May 21;18(5):5954-64.
    PMID: 23698048 DOI: 10.3390/molecules18055954
    The synthesis of nanoparticles has become a matter of great interest in recent times due to their various advantageous properties and applications in a variety of fields. The exploitation of different plant materials for the biosynthesis of nanoparticles is considered a green technology because it does not involve any harmful chemicals. In this study, iron oxide nanoparticles (Fe3O4-NPs) were synthesized using a rapid, single step and completely green biosynthetic method by reduction of ferric chloride solution with brown seaweed (BS, Sargassum muticum) water extract containing sulphated polysaccharides as a main factor which acts as reducing agent and efficient stabilizer. The structural and properties of the Fe3O4-NPs were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray fluorescence spectrometry (EDXRF), vibrating sample magnetometry (VSM) and transmission electron microscopy. The average particle diameter as determined by TEM was found to be 18 ± 4 nm. X-ray diffraction showed that the nanoparticles are crystalline in nature, with a cubic shape. The nanoparticles synthesized through this biosynthesis method can potentially useful in various applications.
    Matched MeSH terms: Chlorides/chemistry; Ferric Compounds/chemistry*; Plant Extracts/chemistry*; Seaweed/chemistry*; Sargassum/chemistry*; Nanoparticles/chemistry*
  8. Assessment of antioxidant activity in Victorian marine algal extracts using high performance thin-layer chromatography and multivariate analysis
    Agatonovic-Kustrin S, Morton DW, Ristivojević P
    J Chromatogr A, 2016 Oct 14;1468:228-235.
    PMID: 27670751 DOI: 10.1016/j.chroma.2016.09.041
    The aim of this study was to develop and validate a rapid and simple high performance thin layer chromatographic (HPTLC) method to screen for antioxidant activity in algal samples. 16 algal species were collected from local Victorian beaches. Fucoxanthin, one of the most abundant marine carotenoids was quantified directly from the HPTLC plates before derivatization, while derivatization either with 2,2-diphenyl-1-picrylhydrazyl (DPPH) or ferric chloride (FeCl3) was used to analyze antioxidants in marine algae, based on their ability to scavenge non biological stable free radical (DPPH) or to chelate iron ions. Principal component analysis of obtained HPTLC fingerprints has classified algae species into 5 groups according to their chemical/antioxidant profiles. The investigated brown algae samples were found to be rich in non-and moderate-polar compounds and phenolic compounds with antioxidant activity. Most of the phenolic iron chelators also have shown free radical scavenging activity. Strong positive and significant correlations between total phenolic content and DPPH radical scavenging activity showed that, phenolic compounds, including flavonoids are the main contributors of antioxidant activity in these species. The results suggest that certain brown algae possess significantly higher antioxidant potential when compared to red or green algae and could be considered for future applications in medicine, dietary supplements, cosmetics or food industries. Cystophora monilifera extract was found to have the highest antioxidant concentration, followed by Zonaria angustata, Cystophora pectinate, Codium fragile, and Cystophora pectinata. Fucoxanthin was found mainly in the brown algae species. The proposed methods provide an edge in terms of screening for antioxidants and quantification of antioxidant constituents in complex mixtures. The current application also demonstrates flexibility and versatility of a standard HPTLC system in the drug discovery. Proposed methods could be used for the bioassay-guided isolation of unknown natural antioxidants and subsequent identification if combined with spectroscopic identification.
    Matched MeSH terms: Phaeophyta/chemistry*; Antioxidants/chemistry*; Biphenyl Compounds/chemistry; Picrates/chemistry; Free Radical Scavengers/chemistry*; Complex Mixtures/chemistry*
  9. Effect of steam sterilisation on lipophilic nutrient stability in a chloroplast-rich fraction (CRF) recovered from postharvest, pea vine field residue (haulm)
    Wattanakul J, Syamila M, Briars R, Ayed C, Price R, Darwish R, et al.
    Food Chem, 2021 Jan 01;334:127589.
    PMID: 32707366 DOI: 10.1016/j.foodchem.2020.127589
    Postharvest, pea vine field residue (haulm) was steam-sterilised and then juiced; a chloroplast-rich fraction (CRF) was recovered from the juice by centrifugation. The stability of selected nutrients (β-carotene, lutein, and α-tocopherol) in the freeze-dried CRF material was measured over 84 days; the impact of temperature (-20 °C, 4 °C, 25 °C and 40 °C), light and air on nutrient stability was established. All three nutrients were stable at -20 °C and 4 °C in the presence or absence of air; this stability was lost at higher temperatures in the presence of air. The extent and rate of nutrient breakdown significantly increased when the CRF samples were exposed to light. β-Carotene appeared to be more susceptible to degradation than lutein and α-tocopherol at 40 °C in the presence of air, but when CRF was exposed to light all three nutrients measured were significantly broken down during storage at 25 °C or 40 °C, whether exposed to air or not.
    Matched MeSH terms: Chloroplasts/chemistry*; Lutein/chemistry; Peas/chemistry*; Plant Stems/chemistry*; beta Carotene/chemistry; alpha-Tocopherol/chemistry
  10. Comparison of oven drying and freeze drying methods for the production of fast melt films containing quetiapine fumarate
    Phang HC, Ng ZQ, Mohamad N, Chew YL, Balaraman A, Kee PE, et al.
    Drug Dev Ind Pharm, 2024 Sep;50(9):810-826.
    PMID: 39320267 DOI: 10.1080/03639045.2024.2409168
    BACKGROUND: Quetiapine fumarate (QTP) is commonly prescribed for schizophrenic patient, typically available in tablet or oral suspension form, presenting challenges such as administration difficulties, fear of choking and distaste for its bitter taste. Fast melt films (FMF) offer an alternative dosage form with a simple development process, ease of administration and rapid drug absorption and action onset.

    OBJECTIVE: This study aims to prepare FMF with different formulations using solvent casting methods and to compare the effects of different drying methods, including oven drying and freeze drying, on the properties of the films.

    METHODS: Various formulations were created by manipulating polymer types (starch, hydroxypropyl methylcellulose (HPMC) and guar gum) at different concentrations, along with fixed concentrations of QTP and other excipients. Characterization tests including surface morphology, weight, thickness, pH, tensile strength, elongation length, Young's modulus, folding endurance and disintegration time were conducted. The optimal FMF formulation was identified and further evaluated for moisture and drug content, dissolution behavior, accelerated stability, X-ray diffraction (XRD), and palatability.

    RESULTS: FMF containing 10 mg guar gum/film developed using oven drying emerged as the optimum choice, exhibiting desirable film appearance, ultra-thin thickness (0.453 ± 0.002 mm), appropriate pH for oral intake (pH 5.0), optimal moisture content of 11.810%, rapid disintegration (52.67 ± 1.53 s), high flexibility (folding endurance > 300 times) and lower Young's modulus (1.308 ± 0.214).

    CONCLUSION: Oven drying method has been proven to be favorable for developing FMF containing QTP, meeting all testing criteria and providing an alternative option for QTP prescription.

    Matched MeSH terms: Chemistry, Pharmaceutical/methods; Mannans/chemistry; Polymers/chemistry; Antipsychotic Agents/chemistry; Hypromellose Derivatives/chemistry
  11. Exploration of underutilized chayote fractions following drying and extraction
    Hussain A, Gorsi FI, Ali MQ, Yaqub S, Asif A, Bibi B, et al.
    Food Chem, 2025 Feb 15;465(Pt 2):142129.
    PMID: 39579399 DOI: 10.1016/j.foodchem.2024.142129
    Valorizing neglected crop byproducts through eco-friendly techniques has gained attention as underutilized crops offer new sources of bioactive components. This study examined the chemical composition, phytochemicals, and antioxidant activities in six fractions of the underutilized chayote (Sechium edule). Each fraction was microwave-dried and extracted with ultrasound assistance. Shoots were high in ash and fiber, while pulp had high moisture and carbohydrates, and seeds were rich in fat and protein. Shoots, leaves, roots, and peels had high mineral levels, particularly Ca, K, Mg, P, Fe, and Zn. Shoots were also high in phenolics, flavonoids, and ascorbic acid, while leaves had a high carotenoid content. Polyphenol compounds such as myricetin and catechin were abundant in shoots, which exhibited the highest antioxidant activity. Chayote shoots, roots, and leaves are abundant in bioactive compounds that can be utilized in food and, therefore, offers an opportunity for utilization of a currently neglected plant byproduct.
    Matched MeSH terms: Flavonoids/chemistry; Phenols/chemistry; Seeds/chemistry; Plant Leaves/chemistry; Plant Roots/chemistry; Phytochemicals/chemistry
  12. Fabrication of an electrochemical sensor based on carbon nanotubes modified with gold nanoparticles for determination of valrubicin as a chemotherapy drug: valrubicin-DNA interaction
    Hajian R, Mehrayin Z, Mohagheghian M, Zafari M, Hosseini P, Shams N
    Mater Sci Eng C Mater Biol Appl, 2015 Apr;49:769-775.
    PMID: 25687007 DOI: 10.1016/j.msec.2015.01.072
    In this study, an electrochemical sensor was fabricated based on gold nanoparticles/ ethylenediamine/ multi-wall carbon-nanotubes modified gold electrode (AuNPs/en/MWCNTs/AuE) for determination of valrubicin in biological samples. Valrubicin was effectively accumulated on the surface of AuNPs/en/MWCNTs/AuE and produced a pair of redox peaks at around 0.662 and 0.578V (vs. Ag/AgCl) in citrate buffer (pH4.0). The electrochemical parameters including pH, buffer, ionic strength, scan rate and size of AuNPs have been optimized. There was a good linear correlation between cathodic peak current and concentration of valrubicin in the range of 0.5 to 80.0μmolL(-1) with the detection limit of 0.018μmolL(-1) in citrate buffer (pH4.0) and 0.1molL(-1) KCl. Finally, the constructed sensor was successfully applied for determination of valrubicin in human urine and blood serum. In further studies, the different sequences of single stranded DNA probes have been immobilized on the surface of AuNPs decorated on MWCNTs to study the interaction of oligonucleotides with valrubicin.
    Matched MeSH terms: DNA/chemistry; Doxorubicin/chemistry; Ethylenediamines/chemistry; Gold/chemistry*; Urine/chemistry; Nanotubes, Carbon/chemistry*; Serum/chemistry; Metal Nanoparticles/chemistry*
  13. Fulltext Analysis of flavone C-glycosides in the leaves of Clinacanthus nutans (Burm. f.) Lindau by HPTLC and HPLC-UV/DAD
    Chelyn JL, Omar MH, Mohd Yousof NS, Ranggasamy R, Wasiman MI, Ismail Z
    ScientificWorldJournal, 2014;2014:724267.
    PMID: 25405231 DOI: 10.1155/2014/724267
    Clinacanthus nutans (family Acanthaceae) has been used for the treatment of inflammation and herpes viral infection. Currently, there has not been any report on the qualitative and quantitative determination of the chemical markers in the leaves of C. nutans. The C-glycosidic flavones such as shaftoside, isoorientin, orientin, isovitexin, and vitexin have been found to be major flavonoids in the leaves of this plant. Therefore, we had developed a two-step method using thin-layer chromatography (TLC) and high pressure liquid chromatography (HPLC) for the rapid identification and quantification of the flavones C-glycosides in C. nutans leaves. The TLC separation of the chemical markers was achieved on silica gel 60 plate using ethyl acetate : formic acid : acetic acid : water (100 : 11 : 11 : 27 v/v/v/v) as the mobile phase. HPLC method was optimized and validated for the quantification of shaftoside, orientin, isovitexin, and vitexin and was shown to be linear in concentration range tested (0.4-200 μg/mL, r(2) ≥ 0.996), precise (RSD ≤ 4.54%), and accurate (95-105%). The concentration of shaftoside, orientin, vitexin, and isovitexin in C. nutans leave samples was 2.55-17.43, 0.00-0.86, 0.00-2.01, and 0.00-0.91 mmol/g, respectively.
    Matched MeSH terms: Flavonoids/chemistry; Glucosides/chemistry; Glycosides/chemistry; Plant Extracts/chemistry; Plant Leaves/chemistry; Acanthaceae/chemistry*; Apigenin/chemistry; Luteolin/chemistry
  14. Fulltext The effect of different parameters on the development of compressive strength of oil palm shell geopolymer concrete
    Kupaei RH, Alengaram UJ, Jumaat MZ
    ScientificWorldJournal, 2014;2014:898536.
    PMID: 25531006 DOI: 10.1155/2014/898536
    This paper presents the experimental results of an on-going research project on geopolymer lightweight concrete using two locally available waste materials--low calcium fly ash (FA) and oil palm shell (OPS)--as the binder and lightweight coarse aggregate, respectively. OPS was pretreated with three different alkaline solutions of sodium hydroxide (NaOH), potassium hydroxide, and sodium silicate as well as polyvinyl alcohol (PVA) for 30 days; afterwards, oil palm shell geopolymer lightweight concrete (OPSGPC) was cast by using both pretreated and untreated OPSs. The effect of these solutions on the water absorption of OPS, and the development of compressive strength in different curing conditions of OPSGPC produced by pretreated OPS were investigated; subsequently the influence of NaOH concentration, alkaline solution to FA ratio (A/FA), and different curing regimes on the compressive strength and density of OPSGPC produced by untreated OPS was inspected. The 24-hour water absorption value for OPS pretreated with 20% and 50% PVA solution was about 4% compared to 23% for untreated OPS. OPSGPC produced from OPS treated with 50% PVA solution produced the highest compressive strength of about 30 MPa in ambient cured condition. The pretreatment with alkaline solution did not have a significant positive effect on the water absorption of OPS aggregate and the compressive strength of OPSGPC. The result revealed that a maximum compressive strength of 32 MPa could be obtained at a temperature of 65°C and curing period of 4 days. This investigation also found that an A/FA ratio of 0.45 has the optimum amount of alkaline liquid and it resulted in the highest level of compressive strength.
    Matched MeSH terms: Hydroxides/chemistry; Plant Oils/chemistry*; Polymers/chemistry*; Polyvinyl Alcohol/chemistry; Sodium Hydroxide/chemistry; Water/chemistry; Potassium Compounds/chemistry; Coal Ash/chemistry
  15. Cholinesterase inhibitory triterpenoids from the bark of Garcinia hombroniana
    Jamila N, Khairuddean M, Yeong KK, Osman H, Murugaiyah V
    J Enzyme Inhib Med Chem, 2015 Feb;30(1):133-9.
    PMID: 24666300 DOI: 10.3109/14756366.2014.895720
    Context: Garcinia hombroniana Pierre, known as manggis hutan in Malaysia is a rich source of xanthones and benzophenones.
    Matched MeSH terms: Antioxidants/chemistry*; Butyrylcholinesterase/chemistry*; Cholinesterase Inhibitors/chemistry*; Cholinesterases/chemistry*; Plant Extracts/chemistry; Triterpenes/chemistry*; Plant Bark/chemistry; Garcinia/chemistry*
  16. Winged bean [Psophorcarpus tetragonolobus (L.) DC] seeds as an underutilised plant source of bifunctional proteolysate and biopeptides
    Yea CS, Ebrahimpour A, Hamid AA, Bakar J, Muhammad K, Saari N
    Food Funct, 2014 May;5(5):1007-16.
    PMID: 24658538 DOI: 10.1039/c3fo60667h
    Hypertension is one of the major causes of cardiovascular-related diseases, which is highly associated with angiotensin-I-converting enzyme (ACE) activity and oxidative stress. In this study, winged bean seed (WBS), a potential source of protein, was utilised for the production of bifunctional proteolysate and biopeptides with ACE inhibitory and antioxidative properties. An enzymatic approach was applied, coupled with pretreatment of shaking and centrifuging techniques to remove endogenous ACE inhibitors prior to proteolysis. ACE inhibition reached its highest activity, 78.5%, after 12 h proteolysis while antioxidative activities, determined using assays involving DPPH˙ radical scavenging activity and metal ion-chelating activity, reached peaks of 65.0% and 65.7% at 8 h and 14 h, respectively. The said bioactivities were proposed to share some common structural requirements among peptides. A two-dimensional approach was employed for characterisation of effective peptides based on hydrophobicity, using RP-HPLC, and isoelectric property, using isoelectric focusing technique. Results revealed that acidic and basic peptides with partially higher hydrophobicity provided higher ACE inhibition activity than did neutral peptides. Finally, by using Q-TOF mass spectrometry, two peptide sequences (YPNQKV and FDIRA) with ACE inhibitory and antioxidative activities were successfully matched with a database. This study indicates that the WBS proteolysate can be a potential bifunctional food ingredient as the identified biopeptides demonstrated both ACE inhibitory and antioxidative activities in vitro.
    Matched MeSH terms: Angiotensin-Converting Enzyme Inhibitors/chemistry*; Antihypertensive Agents/chemistry*; Antioxidants/chemistry; Peptidyl-Dipeptidase A/chemistry; Fabaceae/chemistry*; Plant Proteins/chemistry*; Protein Hydrolysates/chemistry; Seeds/chemistry*
  17. Extraction agents for the removal of polycyclic aromatic hydrocarbons (PAHs) from soil in soil washing technologies
    Lau EV, Gan S, Ng HK, Poh PE
    Environ Pollut, 2014 Jan;184:640-9.
    PMID: 24100092 DOI: 10.1016/j.envpol.2013.09.010
    Polycyclic aromatic hydrocarbons (PAHs) in soil have been recognised as a serious health and environmental issue due to their carcinogenic, mutagenic and teratogenic properties. One of the commonly employed soil remediation techniques to clean up such contamination is soil washing or solvent extraction. The main factor which governs the efficiency of this process is the solubility of PAHs in the extraction agent. Past field-scale soil washing treatments for PAH-contaminated soil have mainly employed organic solvents or water which is either toxic and costly or inefficient in removing higher molecular weight PAHs. Thus, the present article aims to provide a review and discussion of the alternative extraction agents that have been studied, including surfactants, biosurfactants, microemulsions, natural surfactants, cyclodextrins, vegetable oil and solution with solid phase particles. These extraction agents have been found to remove PAHs from soil at percentages ranging from 47 to 100% for various PAHs.
    Matched MeSH terms: Cyclodextrins/chemistry; Plant Oils/chemistry; Polycyclic Hydrocarbons, Aromatic/chemistry*; Soil/chemistry; Soil Pollutants/chemistry*; Solutions/chemistry; Solvents/chemistry; Surface-Active Agents/chemistry
  18. Modified PVA-alginate encapsulated photocatalyst ferro photo gels for Cr(VI) reduction
    Idris A, Misran E, Hassan N, Abd Jalil A, Seng CE
    J Hazard Mater, 2012 Aug 15;227-228:309-16.
    PMID: 22682796 DOI: 10.1016/j.jhazmat.2012.05.065
    In this study magnetic separable photocatalyst beads containing maghemite nanoparticles (γ-Fe(2)O(3)) in polyvinyl alcohol (PVA) polymer were prepared and used in the reduction of Cr(VI) to Cr(III) in an aqueous solution under sunlight. The unique superparamagnetic property of the photocatalyst contributed by the γ-Fe(2)O(3) and robust property of PVA polymer allow the magnetic beads to be recovered easily and reused for at least 7 times without washing. The concentration of γ-Fe(2)O(3) was varied from 8% (v/v) to 27% (v/v) and the results revealed that the beads with 8% (v/v) γ-Fe(2)O(3) exhibited the best performance where Cr(VI) was reduced to Cr(III) in only 30 min under sunlight. The use of the PVA has improved the bead properties and life cycle of beads which is in line with sustainable practices.
    Matched MeSH terms: Alginates/chemistry*; Chromium/chemistry*; Ferric Compounds/chemistry*; Hexuronic Acids/chemistry; Polyvinyl Alcohol/chemistry*; Water Pollutants, Chemical/chemistry*; Glucuronic Acid/chemistry; Metal Nanoparticles/chemistry*
  19. Fulltext Synthesis and characterization of polyethylene glycol mediated silver nanoparticles by the green method
    Shameli K, Ahmad MB, Jazayeri SD, Sedaghat S, Shabanzadeh P, Jahangirian H, et al.
    Int J Mol Sci, 2012;13(6):6639-50.
    PMID: 22837654 DOI: 10.3390/ijms13066639
    The roles of green chemistry in nanotechnology and nanoscience fields are very significant in the synthesis of diverse nanomaterials. Herein, we report a green chemistry method for synthesized colloidal silver nanoparticles (Ag NPs) in polymeric media. The colloidal Ag NPs were synthesized in an aqueous solution using silver nitrate, polyethylene glycol (PEG), and β-D-glucose as a silver precursor, stabilizer, and reducing agent, respectively. The properties of synthesized colloidal Ag NPs were studied at different reaction times. The ultraviolet-visible spectra were in excellent agreement with the obtained nanostructure studies performed by transmission electron microscopy (TEM) and their size distributions. The Ag NPs were characterized by utilizing X-ray diffraction (XRD), zeta potential measurements and Fourier transform infrared (FT-IR). The use of green chemistry reagents, such as glucose, provides green and economic features to this work.
    Matched MeSH terms: Colloids/chemistry; Glucose/chemistry; Polyethylene Glycols/chemistry*; Polymers/chemistry; Silver/chemistry*; Reducing Agents/chemistry; Nanostructures/chemistry; Metal Nanoparticles/chemistry*
  20. Synthesis of fatty acid methyl ester from palm oil (Elaeis guineensis) with Ky(MgCa)2xO3 as heterogeneous catalyst
    Olutoye MA, Lee SC, Hameed BH
    Bioresour Technol, 2011 Dec;102(23):10777-83.
    PMID: 21983406 DOI: 10.1016/j.biortech.2011.09.033
    Fatty acid methyl esters (FAME) were produced from palm oil using eggshell modified with magnesium and potassium nitrates to form a composite, low-cost heterogeneous catalyst for transesterification. The catalyst, prepared by the combination of impregnation/co-precipitation was calcined at 830 °C for 4 h. Transesterification was conducted at a constant temperature of 65 °C in a batch reactor. Design of experiment (DOE) was used to optimize the reaction parameters, and the conditions that gave highest yield of FAME (85.8%) was 5.35 wt.% catalyst loading at 4.5 h with 16:1 methanol/oil molar ratio. The results revealed that eggshell, a solid waste, can be utilized as low-cost catalyst after modification with magnesium and potassium nitrates for biodiesel production.
    Matched MeSH terms: Methanol/chemistry; Chemistry/methods; Nitrates/chemistry; Oils/chemistry; Plant Oils/chemistry*; Magnesium Compounds/chemistry; Potassium Compounds/chemistry
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