Displaying publications 1021 - 1040 of 10377 in total

Abstract:
Sort:
  1. Iridoids and anthraquinones from the Malaysian medicinal plant, Saprosma scortechinii (Rubiaceae)
    Ling SK, Komorita A, Tanaka T, Fujioka T, Mihashi K, Kouno I
    Chem Pharm Bull (Tokyo), 2002 Aug;50(8):1035-40.
    PMID: 12192133
    A further investigation of the leaves and stems of Saprosma scortechinii afforded 13 compounds, of which 10 are new compounds. These were elucidated as the bis-iridoid glucosides, saprosmosides G (1) and H (2), the iridoid glucoside, 6-O-epi-acetylscandoside (3), and the anthraquinones, 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone (4), 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone 3-O-beta-primeveroside (5), 1,3-dihydroxy-2-carbomethoxy-9,10-anthraquinone 3-O-beta-primeveroside (6), 1,3,6-trihydroxy-2-methoxymethyl-9,10-anthraquinone (7), 1-methoxy-3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (8), 1,3,6-trihydroxy-2-hydroxymethyl-9,10-anthraquinone 3-O-beta-primeveroside (9), and 3,6-dihydroxy-2-hydroxymethyl-9,10-anthraquinone (10). Structure assignments for all compounds were established by means of mass and NMR spectroscopies, chemical methods, and comparison with published data. The new anthraquinones were derivatives of munjistin and lucidin.
    Matched MeSH terms: Anthraquinones/chemistry; Plant Extracts/chemistry; Plants, Medicinal/chemistry; Plant Leaves/chemistry; Plant Stems/chemistry; Iridoids/chemistry
  2. Purification and characterization of 31-kDa palm pollen glycoprotein (Ela g Bd 31 K), which is recognized by IgE from palm pollinosis patients
    Kimura Y, Maeda M, Kimupa M, Lai OM, Tan SH, Hon SM, et al.
    Biosci Biotechnol Biochem, 2002 Apr;66(4):820-7.
    PMID: 12036055
    A basic glycoprotein, which was recognized by IgE from oil palm pollinosis patients, has been purified from oil palm pollen (Elaeis guineensis Jacq.), which is a strong allergen and causes severe pollinosis in Malaysia and Singapore. Soluble proteins were extracted from defatted palm pollen with both Tris-HCl buffer (pH 7.8) and Na-acetate buffer (pH 4.0). The allergenic glycoprotein was purified from the total extract to homogeneity with 0.4% yield by a combination of DEAE- and CM-cellulose, SP-HPLC, and gel filtration. The purified oil palm pollen glycoprotein with molecular mass of 31 kDa was recognized by the beta1-2 xylose specific antibody, suggesting this basic glycoprotein bears plant complex type N-glycan(s). The palm pollen basic glycoprotein, designated Ela g Bd 31 K, was recognized by IgE of palm pollinosis patients, suggesting Ela g Bd 31 K should be one of the palm pollen allergens. The preliminary structural analysis of N-glycans linked to glycoproteins of palm pollens showed that the antigenic N-glycans having alpha1-3 fucose and alpha1-2 xylose residues (GlcNAc(2 to approximately 0)Man3Xyl1Fuc(1 to approximately 0)GlcNAc2) actually occur on the palm pollen glycoproteins, in addition to the high-mannose type structures (Man(9 to approximately 5)GlcNAc2).
    Matched MeSH terms: Allergens/chemistry*; Glycoproteins/chemistry*; Oligosaccharides/chemistry*; Plant Proteins/chemistry*; Pollen/chemistry*; Arecaceae/chemistry*
  3. Permeability improvement of polyethersulfone-polietylene glycol (PEG-PES) flat sheet type membranes by tripolyphosphate-crosslinked chitosan (TPP-CS) coating
    Lusiana RA, Sangkota VDA, Sasongko NA, Gunawan G, Wijaya AR, Santosa SJ, et al.
    Int J Biol Macromol, 2020 Jun 01;152:633-644.
    PMID: 32112845 DOI: 10.1016/j.ijbiomac.2020.02.290
    In this study, improvement of urea and creatinine permeability of polyethersulfone (PES) membrane by coating with synthesized tripolyphosphate-crosslinked chitosan (TPP-CS) has been conducted. Original and modified membranes, e.g. pristine PES, polyethersulfone-polyethylene glycol (PES-PEG) and PES-PEG/TPP-CS membranes were characterized using FTIR, DTG, SEM, AFM, water uptake, contact angles, porosity measurement, tensile strength test and permeation tests against urea and creatinine. The results show that the PES modification by TPP-CS coating has been successfully carried out. The water uptake ability, hydrophilicity and porosity of the modified membranes increase significantly to a greater degree. All modified membranes have good thermal stability and tensile strength and their permeation ability towards urea and creatinine increase with the increasing concentration of TPP-CS. PES membrane has urea clearance ability of 7.36 mg/dL and creatinine of 0.014 mg/dL; membrane PES-PEG shows urea clearance of 11.87 mg/dL and creatinine of 0.32 mg/dL; while PES-PEG/TPP-CS membrane gives urea clearance of 20.87-36.40 mg/dL and creatinine in the range of 0.52-0.78 mg/dL. These results suggest that the PES-PEG membrane coated with TPP-CS is superior and can be used as potential material for hemodialysis membrane.
    Matched MeSH terms: Membranes/chemistry; Polyethylene Glycols/chemistry*; Polymers/chemistry*; Polyphosphates/chemistry*; Sulfones/chemistry*; Chitosan/chemistry*
  4. Recovery of value-added glycopeptides from edible bird's nest (EBN) co-products: enzymatic hydrolysis, physicochemical characteristics and bioactivity
    Ling JWA, Chang LS, Babji AS, Lim SJ
    J Sci Food Agric, 2020 Oct;100(13):4714-4722.
    PMID: 32468613 DOI: 10.1002/jsfa.10530
    BACKGROUND: Processing of edible bird's nest (EBN) requires extensive washing to remove impurities and produces huge amounts of EBN co-products, which contain mainly feathers with glycoproteins attached, which are usually discarded. This study was conducted to recover the valuable EBN glycoproteins from the waste material. Enzymatic hydrolysis was applied to recover EBN glycopeptides from EBN co-products (EBNcoP ) and processed cleaned EBN (EBNclean ) was used as control, which were then freeze-dried into EBN hydrolysates (EBNhcoP and EBNhclean , respectively).

    RESULTS: The recovery yield for EBNhclean and EBNhcoP were 89.09 ± 0.01% and 47.64 ± 0.26%, respectively, indicating nearly 50% of glycopeptide can be recovered from the waste material. Meanwhile, N-acetylneuraminic acid, a major acid sugar in EBN glycoproteins, of EBNhcoP increased by 229% from 58.6 ± 3.9 to 192.9 ± 3.1 g kg-1 , indicating the enzymatic hydrolysis removed impurities and thus enhanced the N-acetylneuraminic acid content. Total soluble protein was more than 330 g kg-1 for all the samples. Colour parameter showed that hydrolysate samples have greater L* (lightness) values. Chroma result indicates the intensity of all the samples were low (

    Matched MeSH terms: Antioxidants/chemistry; Biological Products/chemistry*; Enzymes/chemistry; Feathers/chemistry; Glycopeptides/chemistry*; Saliva/chemistry*
  5. Distribution of mercury in sediments, plant and animal tissues in Matang Mangrove Forest Reserve, Malaysia
    Wolswijk G, Satyanarayana B, Dung LQ, Siau YF, Ali ANB, Saliu IS, et al.
    J Hazard Mater, 2020 04 05;387:121665.
    PMID: 31784131 DOI: 10.1016/j.jhazmat.2019.121665
    Charcoal production activities at the Matang Mangrove Forest Reserve (MMFR) in Peninsular Malaysia have a potential to emit volatile compounds such as Hg back into the ambient environment, raising concerns on the public health and safety. The present study was aimed at analyzing Hg concentration from different plant/animal tissues and sediment samples (in total 786 samples) to understand clearly the Hg distribution at the MMFR. Leaves of Rhizophora spp. showed higher Hg concentration with an increasing trend from young, to mature, to senescent and decomposing stages, which was possibly due to accumulation of Hg over time. The low Hg concentration in Rhizophora roots and bark suggests a limited absorption from the sediments and a meagre accumulation/partitioning by the plant tissue, respectively. In the case of mangrove cockles the concentration of Hg was lower than the permissible limits for seafood consumption. Although the mangrove gastropod - Cassidula aurisfelis Bruguière had rather elevated Hg in the muscle tissue, it is still less than the environmental safely limit. Beside the chances of atmospheric deposition for Hg, the sediment samples were found to be unpolluted in nature, indicating that in general the MMFR is still safe in terms of Hg pollution.
    Matched MeSH terms: Plant Leaves/chemistry; Plant Roots/chemistry; Geologic Sediments/chemistry; Rhizophoraceae/chemistry; Gastropoda/chemistry; Bivalvia/chemistry
  6. Inhibitory activity of cyclohexenyl chalcone derivatives and flavonoids of fingerroot, Boesenbergia rotunda (L.), towards dengue-2 virus NS3 protease
    Kiat TS, Pippen R, Yusof R, Ibrahim H, Khalid N, Rahman NA
    Bioorg Med Chem Lett, 2006 Jun 15;16(12):3337-40.
    PMID: 16621533
    Boesenbergia rotunda (L.) cyclohexenyl chalcone derivatives, 4-hydroxypanduratin A and panduratin A, showed good competitive inhibitory activities towards dengue 2 virus NS3 protease with the Ki values of 21 and 25 microM, respectively, whilst those of pinostrobin and cardamonin were observed to be non-competitive. NMR and GCMS spectroscopic data formed the basis of assignment of structures of the six compounds isolated.
    Matched MeSH terms: Chalcone/chemistry*; Cyclohexanes/chemistry*; Flavonoids/chemistry*; Protease Inhibitors/chemistry*; Plant Roots/chemistry; Zingiberaceae/chemistry*
  7. Synthesis and characterization of polyacids from palm acid oil and sunflower oil via addition reaction
    Zeimaran E, Kadir MR, Nor HM, Kamarul T, Djordjevic I
    Bioorg Med Chem Lett, 2013 Dec 15;23(24):6616-9.
    PMID: 24215893 DOI: 10.1016/j.bmcl.2013.10.053
    In this study aliphatic polyacids were synthesized using palm acid oil (PAO) and sunflower oil (SFO) via addition reaction technique. The synthesized materials were characterized using Fourier-transform infra-red (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF-MS) and thermo-gravimetric analysis (TGA). Mixing formic acid and hydrogen peroxide with PAO or SFO at the ratio 3:10:1 produced the lowest iodine value of 10.57 and 9.24 respectively, indicating the increase in epoxidization of both oils. Adding adipic acid to the epoxidized oils at a ratio of 1:10 increases the acid values of SFO and PAO to 11.22 and 6.73 respectively. The existence of multi-acid groups present in synthesized polyacid was confirmed by MALD-ToF-MS. This feature indicates a possible value to the biomaterials development.
    Matched MeSH terms: Acids/chemistry*; Epoxy Compounds/chemistry; Fatty Acids, Unsaturated/chemistry; Formates/chemistry; Hydrogen Peroxide/chemistry; Plant Oils/chemistry*
  8. One-pot lipase-catalyzed esterification of ε-caprolactone with methyl-d-glucopyranoside and its elongation with free 6-hydroxyhexanoate monomer units
    Saat MN, Mohamad Annuar MS
    Biotechnol Appl Biochem, 2020 May;67(3):354-365.
    PMID: 31746015 DOI: 10.1002/bab.1859
    One-pot synthesis of sugar-functionalized oligomeric caprolactone was carried out by lipase-catalyzed esterification of ε-caprolactone (ECL) with methyl-d-glucopyranoside (MGP) followed by the elongation of functionalized oligomer chain. Functionalization was performed in a custom-fabricated glass reactor equipped with Rushton turbine impeller and controlled temperature at 60 °C using tert-butanol as reaction medium. The overall reaction steps include MGP esterification of ECL monomer and its subsequent elongation by free 6-hydroxyhexanoate monomer units. A ping-pong bi-bi mechanism without ternary complex was proposed for esterification of ECL and MGP with apparent values of kinetic constant, namely maximal velocity (Vmax ), Michaelis constant for MGP (KmMGP ), and Michaelis constant for ECL (KmECL ) at 3.848 × 10-3  M H-1 , 8.189 × 10-2  M, and 6.050 M, respectively. Chain propagation step of MGP-functionalized ECL oligomer exhibits the properties of living polymerization mechanism. Linear relationship between conversion (%) and number average molecular weight, Mn (g mol-1 ), of functionalized oligomer was observed. Synthesized functionalized oligomer showed narrow range of molecular weight from 1,400 to 1,600 g mol-1 with more than 90% conversion achieved. Structural analysis confirmed the presence of covalent bond between the hydroxyl group in MGP with carboxyl end group of ECL oligomer.
    Matched MeSH terms: Caproates/chemistry; Enzymes, Immobilized/chemistry; Hydroxy Acids/chemistry; Lactones/chemistry; Lipase/chemistry; Methylglycosides/chemistry
  9. Fabrication and evaluation of bacterial nanocellulose/poly(acrylic acid)/graphene oxide composite hydrogel: Characterizations and biocompatibility studies for wound dressing
    Chen XY, Low HR, Loi XY, Merel L, Mohd Cairul Iqbal MA
    J Biomed Mater Res B Appl Biomater, 2019 08;107(6):2140-2151.
    PMID: 30758129 DOI: 10.1002/jbm.b.34309
    Graphene oxide (GO) is a potential material for wound dressing due to its excellent biocompatibility and mechanical properties. This study evaluated the effects of GO concentration on the synthesis of bacterial nanocellulose (BNC)-grafted poly(acrylic acid) (AA)-graphene oxide (BNC/P(AA)/GO) composite hydrogel and its potential as wound dressing. Hydrogels were successfully synthesized via electron-beam irradiation. The hydrogels were characterized by their mechanical properties, bioadhesiveness, water vapor transmission rates (WVTRs), water retention abilities, water absorptivity, and biocompatibility. Fourier transform infrared analysis showed the successful incorporation of GO into hydrogel. Thickness, gel fraction determination and morphological study revealed that increased GO concentration in hydrogels leads to reduced crosslink density and larger pore size, resulting in increased WVTR. Thus, highest swelling ratio was found in hydrogel with higher amount of GO (0.09 wt %). The mechanical properties of the composite hydrogel were maintained, while its hardness and bioadhesion were reduced with higher GO concentration in the hydrogel, affirming the durable and easy removable properties of a wound dressing. Human dermal fibroblast cell attachment and proliferation studies showed that biocompatibility of hydrogel was improved with the inclusion of GO in the hydrogel. Therefore, BNC/P(AA)/GO composite hydrogel has a potential application as perdurable wound dressing. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2140-2151, 2019.
    Matched MeSH terms: Acrylic Resins/chemistry*; Bacteria/chemistry*; Cellulose/chemistry*; Graphite/chemistry*; Hydrogels/chemistry*; Nanocomposites/chemistry*
  10. Optimized preparation and characterization of CLEA-lipase from cocoa pod husk
    Khanahmadi S, Yusof F, Amid A, Mahmod SS, Mahat MK
    J Biotechnol, 2015 May 20;202:153-61.
    PMID: 25481099 DOI: 10.1016/j.jbiotec.2014.11.015
    Cross-linked enzyme aggregate (CLEA) is easily prepared from crude enzyme and has many advantages to the environment and it is considered as an economic method in the context of industrial biocatalysis compared to free enzyme. In this work, a highly active and stable CLEA-lipase from cocoa pod husk (CPH) which is a by-product after removal of cocoa beans, were assayed for their hydrolytic activity and characterized under the optimum condition successfully. Face centered central composite design (FCCCD) under response surface methodology (RSM) was used to get the optimal conditions of the three significant factors (concentration of ammonium sulfate, concentration of glutaraldehyde and concentration of additive) to achieve higher enzyme activity of CLEA. From 20 runs, the highest activity recorded was around 9.407U (83% recovered activity) under the condition of using 20% saturated ammonium sulfate, 60mM glutaraldehyde as cross-linker and 0.17mM bovine serum albumin as feeder. Moreover, the optimal reaction temperature and pH value in enzymatic reaction for both crude enzyme and immobilized were found to be 45°C at pH 8 and 60°C at pH 8.2, respectively. A systematic study of the stability of CLEA and crude enzyme was taken with regards to temperature (25-60°C) and pH (5-10) value and in both factors, CLEA-lipase showed more stability than free lipase. The Km value of CLEA was higher compared to free enzyme (0.55mM vs. 0.08mM). The CLEA retained more than 60% of the initial activity after six cycles of reuse compared to free enzyme. The high stability and recyclability of CLEA-lipase from CPH make it efficient for different industrial applications.
    Matched MeSH terms: Ammonium Sulfate/chemistry; Cross-Linking Reagents/chemistry; Enzymes, Immobilized/chemistry; Glutaral/chemistry; Lipase/chemistry*; Plant Proteins/chemistry
  11. Fulltext Characterization and multi-step transketolase-ω-transaminase bioconversions in an immobilized enzyme microreactor (IEMR) with packed tube
    Halim AA, Szita N, Baganz F
    J Biotechnol, 2013 Dec;168(4):567-75.
    PMID: 24055435 DOI: 10.1016/j.jbiotec.2013.09.001
    The concept of de novo metabolic engineering through novel synthetic pathways offers new directions for multi-step enzymatic synthesis of complex molecules. This has been complemented by recent progress in performing enzymatic reactions using immobilized enzyme microreactors (IEMR). This work is concerned with the construction of de novo designed enzyme pathways in a microreactor synthesizing chiral molecules. An interesting compound, commonly used as the building block in several pharmaceutical syntheses, is a single diastereoisomer of 2-amino-1,3,4-butanetriol (ABT). This chiral amino alcohol can be synthesized from simple achiral substrates using two enzymes, transketolase (TK) and transaminase (TAm). Here we describe the development of an IEMR using His6-tagged TK and TAm immobilized onto Ni-NTA agarose beads and packed into tubes to enable multi-step enzyme reactions. The kinetic parameters of both enzymes were first determined using single IEMRs evaluated by a kinetic model developed for packed bed reactors. The Km(app) for both enzymes appeared to be flow rate dependent, while the turnover number kcat was reduced 3 fold compared to solution-phase TK and TAm reactions. For the multi-step enzyme reaction, single IEMRs were cascaded in series, whereby the first enzyme, TK, catalyzed a model reaction of lithium-hydroxypyruvate (HPA) and glycolaldehyde (GA) to L-erythrulose (ERY), and the second unit of the IEMR with immobilized TAm converted ERY into ABT using (S)-α-methylbenzylamine (MBA) as amine donor. With initial 60mM (HPA and GA each) and 6mM (MBA) substrate concentration mixture, the coupled reaction reached approximately 83% conversion in 20 min at the lowest flow rate. The ability to synthesize a chiral pharmaceutical intermediate, ABT in relatively short time proves this IEMR system as a powerful tool for construction and evaluation of de novo pathways as well as for determination of enzyme kinetics.
    Matched MeSH terms: Acetaldehyde/chemistry; Amines/chemistry*; Amino Alcohols/chemistry; Transaminases/chemistry*; Enzymes, Immobilized/chemistry*; Transketolase/chemistry*
  12. Chemical composition and anticholinesterase inhibitory activity of Pavetta graciliflora Wall. ex Ridl. essential oil
    Salleh WMNHW, Khamis S
    Z Naturforsch C J Biosci, 2020 Nov 26;75(11-12):467-471.
    PMID: 32469335 DOI: 10.1515/znc-2020-0075
    Chemical composition and anticholinesterase activity of the essential oil of Pavetta graciliflora Wall. ex Ridl. (Rubiaceae) was examined for the first time. The essential oil was obtained by hydrodistillation and was fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 20 components were identified in the essential oil, which made up 92.85% of the total oil. The essential oil is composed mainly of β-caryophyllene (42.52%), caryophyllene oxide (25.33%), β-pinene (8.67%), and α-pinene (6.52%). The essential oil showed weak inhibitory activity against acetylcholinesterase (AChE) (I%: 62.5%) and butyrylcholinesterase (BChE) (I%: 65.4%) assays. Our findings were shown to be very useful for the characterization, pharmaceutical, and therapeutic applications of the essential oil from P. graciliflora.
    Matched MeSH terms: Acetylcholinesterase/chemistry*; Antioxidants/chemistry; Butyrylcholinesterase/chemistry; Cholinesterase Inhibitors/chemistry; Oils, Volatile/chemistry*; Rubiaceae/chemistry*
  13. Fulltext Preparation and characterization of nano liposomes of Orthosiphon stamineus ethanolic extract in soybean phospholipids
    Aisha AF, Majid AM, Ismail Z
    BMC Biotechnol, 2014;14:23.
    PMID: 24674107 DOI: 10.1186/1472-6750-14-23
    O. stamineus is a medicinal herb with remarkable pharmacological properties. However, poor solubility of the active principles limits its medicinal value. This study sought to prepare nano liposomes of OS ethanolic extract in unpurified soybean phospholipids in order to improve its solubility and permeability. OS liposomes were prepared by the conventional film method, and were characterized for solubility, entrapment efficiency, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), particle size and zeta potential, release, absorption in everted rat intestinal sacs, and DPPH scavenging effect.
    Matched MeSH terms: Liposomes/chemistry*; Phospholipids/chemistry*; Plant Extracts/chemistry*; Soybeans/chemistry; Orthosiphon/chemistry*; Nanoparticles/chemistry*
  14. Synthesis and characterization of polymeric V2O5/AlO(OH) with nanopores on alumina support
    Ahmad AL, Abd Shukor SR, Leo CP
    J Nanosci Nanotechnol, 2006 Dec;6(12):3910-4.
    PMID: 17256351
    Polymeric vanadium pentoxide gel was formed via the reaction of V2O5 powder with hydrogen peroxide. The polymeric vanadium pentoxide gel was then dispersed in alumina gel. Different vanadium loading composites were coated on alumina support and calcined at 500 degrees C for 1 hr. These composite layers were characterized using TGA, FT-IR, XRD, SEM, and Autosorb. It was found that the lamellar structure of polymerized vanadium pentoxide was retained in the inorganic matrix. Crystalline alumina in gamma phase was formed after calcinations. However, the vanadium-alumina mixed oxides are lack of the well defined PXRD peaks for polycrystalline V2O5. This is possibly because the vanadia species are highly dispersed in the alumina matrix or the vanadia species are dispersed as crystalline which is smaller than 4 nm. In addition, the imbedded polymeric vanadium oxide improved the specific area and average pore diameter of the composite layer.
    Matched MeSH terms: Aluminum Oxide/chemistry*; Gels/chemistry; Polymers/chemistry; Vanadium Compounds/chemistry*; Macromolecular Substances/chemistry; Nanostructures/chemistry*
  15. The effect of oleic acid stabilizer on the surface properties of bimetallic PtNi catalysts
    Abu Bakar NH, Abu Bakar M, Bettahar MM, Ismail J, Monteverdi S
    J Nanosci Nanotechnol, 2013 Jul;13(7):5034-43.
    PMID: 23901527
    A detailed study on the surface properties of oleic acid-stabilized PtNi nanoparticles supported on silica is reported. The oleic acid-stabilized PtNi nanoparticles were synthesized using NaBH4 as the reducing agent at various temperatures and oleic acid concentrations, prior to incorporation onto the silica support. X-ray diffraction studies of the unsupported oleic acid-stabilized PtNi particles revealed that the PtNi existed as alloys. Upon incorporation onto silica support, surface properties of the catalysts were investigated using H2-temperature reduction (H2-TPR), H2-temperature desorption (H2-TPD) and H2-chemisorption techniques. It was found that for the bimetallic catalysts, no oxides or very little oxidation occurred. Furthermore, these catalysts exhibited both Pt and Ni active sites on its surface though the availability of Ni active sites was dominant. A comparison of the surface properties of these materials with those prepared without oleic acid in our previous work [N. H. H. Abu Bakar et al., J. Catal. 265, 63 (2009)] and how they affect the hydrogenation of benzene is also discussed.
    Matched MeSH terms: Alloys/chemistry; Excipients/chemistry; Nickel/chemistry*; Platinum/chemistry*; Oleic Acid/chemistry*; Metal Nanoparticles/chemistry*
  16. Fulltext Experimental and Theoretical Studies on Extract of Date Palm Seed as a Green Anti-Corrosion Agent in Hydrochloric Acid Solution
    Mohammed NJ, Othman NK, Taib MFM, Samat MH, Yahya S
    Molecules, 2021 Jun 09;26(12).
    PMID: 34207914 DOI: 10.3390/molecules26123535
    Extracts from plant materials have great potential as alternatives to inorganic corrosion inhibitors, which typically have harmful consequences. Experimental and theoretical methodologies studied the effectiveness of agricultural waste, namely, date palm seed extract as a green anti-corrosive agent in 0.5 M hydrochloric acid. Experimental results showed that immersion time and temperature are closely related to the effectivity of date palm seed as a corrosion inhibitor. The inhibition efficiency reduced from 95% to 91% at 1400 ppm when the immersion time was increased from 72 h to 168 h. The experimental results also indicated that the inhibition efficiency decreased as the temperature increased. The presence of a protective layer of organic matter was corroborated by scanning electron microscopy. The adsorption studies indicated that date palm seed obeyed Langmuir adsorption isotherm on the carbon steel surface, and Gibbs free energy values were in the range of -33.45 to -38.41 kJ·mol-1. These results suggested that the date palm seed molecules interacted with the carbon steel surface through mixture adsorption. Theoretical calculations using density functional theory showed that the capability to donate and accept electrons between the alloy surface and the date palm seed inhibitor molecules is critical for adsorption effectiveness. The HOMO and LUMO result indicated that the carboxyl (COOH) group and C=C bond were the most active sites for the electron donation-acceptance type of interaction and most auxiliary to the adsorption process over the Fe surface.
    Matched MeSH terms: Carbon/chemistry*; Hydrochloric Acid/chemistry*; Plant Extracts/chemistry; Seeds/chemistry*; Steel/chemistry*; Phoeniceae/chemistry*
  17. Fulltext Nutritional content and in vitro antioxidant potential of Garcinia atroviridis (Asam gelugor) leaves and fruits
    Nursakinah I, Zulkhairi HA, Norhafizah M, Hasnah B, Zamree MS, Farrah SI, et al.
    Malays J Nutr, 2012 Dec;18(3):363-71.
    PMID: 24568077 MyJurnal
    The objective of this study was to determine antioxidant potential of Garcinia atroviridis leaves and fruits extracts in vitro.
    Matched MeSH terms: Biphenyl Compounds/chemistry; Ferric Compounds/chemistry; Fruit/chemistry*; Picrates/chemistry; Plant Extracts/chemistry; Plant Leaves/chemistry*
  18. The effects of Lycium barbarum water extract and fish collagen on milk proteolysis and in vitro angiotensin I-converting enzyme inhibitory activity of yogurt
    Shori AB, Ming KS, Baba AS
    Biotechnol Appl Biochem, 2021 Apr;68(2):221-229.
    PMID: 32249982 DOI: 10.1002/bab.1914
    Plain and Lycium barbarum yogurt were made in the presence and absence of fish collagen. Yogurt samples were analyzed for acidification, milk protein proteolysis, angiotensin I-converting enzyme (ACE) inhibitory activity, and sensory evaluation during refrigerated storage for up to 21 days. The o-phthaldialdehyde peptides amount of L. barbarum yogurt both in the presence and absence of fish collagen were significantly increased during 14 days of storage. SDS-PAGE showed improvement in whey proteins degradation of L. barbarum yogurt with/without fish collagen after 3 weeks of storage. L. barbarum yogurt in absence of fish collagen was acting as a great ACE inhibitor reached up to 85% on day 7 of storage. The incorporation of L. barbarum and/or fish collagen affected to a small extent the overall sensory characteristics of yogurt. Yogurt supplemented with L. barbarum and/or fish collagen may lead to the improvement in the production and formulation of yogurt differing in their anti-ACE activity.
    Matched MeSH terms: Angiotensin-Converting Enzyme Inhibitors/chemistry*; Collagen/chemistry*; Milk Proteins/chemistry*; Plant Extracts/chemistry*; Fish Proteins/chemistry*; Lycium/chemistry*
  19. Fulltext Comparative performance of two commercial neonicotinoid baits against filth flies under field conditions
    Nurita AT, Abu Hassan A
    Trop Biomed, 2010 Dec;27(3):559-65.
    PMID: 21399598 MyJurnal
    Two performance (efficacy and attractiveness) comparisons of neonicotinoid baits QuickBayt® (imidacloprid) and Agita® (thiamethoxam) against filth flies were conducted under field conditions to determine suitability for use outdoors. The first experiment compared bait performance and the second compared effects of different applications on QuickBayt® performance. Applications compared were: (i) scattered in petri dish (SPD); (ii) wet-down in petri dish (WPD); (iii) scattered on cardboard (SCB) and (iv) painted on cardboards (PCB). Efficacy and attractiveness were assessed based on knockdown percentage (KD%) and number of flies feeding on baits, respectively. The KD% of QuickBayt® (34% ± 3.0%) was not significantly higher than Agita® (29% ± 1.3%) (t-test, P>0.05). Agita® (101 ± 5.7 flies) was significantly more attractive to flies than QuickBayt® (76 ± 4.8 flies) and the sugar solution (49 ± 7.2) (one-way ANOVA, P<0.05). The PCB and SCB applications were significantly more attractive to filth flies than WPD and SPD (One-way ANOVA, P<0.05), however differences in KD% were not significantly different (One-way ANOVA, P>0.05). The two baits provided the same level of efficacy in a wide-open area against filth flies of various species. QuickBayt® was more versatile; efficacy was not significantly affected by different applications. Surface area and moisture affects attractiveness of the bait.
    Matched MeSH terms: Imidazoles/chemistry; Insecticides/chemistry; Nitro Compounds/chemistry; Oxazines/chemistry; Pheromones/chemistry*; Thiazoles/chemistry
  20. Centrifugal air-assisted melt agglomeration for fast-release "granulet" design
    Wong TW, Musa N
    Int J Pharm, 2012 Jul 1;430(1-2):184-96.
    PMID: 22531845 DOI: 10.1016/j.ijpharm.2012.04.026
    Conventional melt pelletization and granulation processes produce round and dense, and irregularly shaped but porous agglomerates respectively. This study aimed to design centrifugal air-assisted melt agglomeration technology for manufacture of spherical and yet porous "granulets" for ease of downstream manufacturing and enhancing drug release. A bladeless agglomerator, which utilized shear-free air stream to mass the powder mixture of lactose filler, polyethylene glycol binder and poorly water-soluble tolbutamide drug into "granulets", was developed. The inclination angle and number of vane, air-impermeable surface area of air guide, processing temperature, binder content and molecular weight were investigated with reference to "granulet" size, shape, texture and drug release properties. Unlike fluid-bed melt agglomeration with vertical processing air flow, the air stream in the present technology moved centrifugally to roll the processing mass into spherical but porous "granulets" with a drug release propensity higher than physical powder mixture, unprocessed drug and dense pellets prepared using high shear mixer. The fast-release attribute of "granulets" was ascribed to porous matrix formed with a high level of polyethylene glycol as solubilizer. The agglomeration and drug release outcomes of centrifugal air-assisted technology are unmet by the existing high shear and fluid-bed melt agglomeration techniques.
    Matched MeSH terms: Chemistry, Pharmaceutical; Excipients/chemistry*; Hypoglycemic Agents/chemistry*; Lactose/chemistry; Polyethylene Glycols/chemistry; Tolbutamide/chemistry*
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links