scholarly journals Fucoidan Extracted From Sporophyll of Undaria pinnatifida Grown in Weihai, China – Chemical Composition and Comparison of Antioxidant Activity of Different Molecular Weight Fractions

2021 ◽  
Vol 8 ◽  
Author(s):  
Jing Yu ◽  
Qianqian Li ◽  
Jun Wu ◽  
Xiaotong Yang ◽  
Shiping Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Chemical Composition ◽  
Undaria Pinnatifida ◽  
Resonance Spectroscopy ◽  
Antioxidant Ability ◽  
Carbohydrate Polymer ◽  
Ft Ir ◽  
Primary Antioxidant ◽  
Ir Analysis ◽  
Molecular Weight Fractions

Fucoidan is a multifunctional marine carbohydrate polymer that differs in its chemical composition and bioactivity both between seaweed species and within species from different locations across the globe. In this study, fucoidan was extracted from the sporophyll of Undaria pinnatifida grown in Weihai, Shandong Province, China. Fucoidan fractions with molecular weight cutoffs (MWCO) of >300 kDa and <10 kDa were obtained via dialysis. The fucoidan standard from Sigma (Fstd, ≥95, CAS: 9072-19-9), fucoidan crude extract (WH), >300 kDa fraction (300k) and <10 kDa fraction (10k) were compared in terms of chemical composition and antioxidant capacity. Based on Fourier transform infrared spectroscopy (FT-IR) analysis, Fstd, WH, and 300k all showed strong bands around 830 cm−1, corresponding to the sulfate substituent in the molecule. The results showed that compared with WH and 300 k, the degree of sulfation at 10k was the lowest. From Nuclear magnetic resonance spectroscopy (NMR) result, the four fucoidan samples all contain α-L-fucose. The primary antioxidant ability of the 10k is significantly higher than that of the 300k, WH, and Fstd, but the secondary antioxidant capabilities of the 10k and 300k were similar, and both were higher than that of the butylated hydroxyanisole (BHA). The ferric reducing antioxidant ability was higher in the 300k and WH fractions. This demonstrates that fucoidan extracted from U. pinnatifida grown in Weihai, China should be a useful nutraceutical resource.

scholarly journals The Synthesis of Low-Viscosity Organotin-Free Moisture-Curable Silane-Terminated Poly(Urethane-Urea)s

Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 781 ◽  
Author(s):  
Chen Tan ◽  
Viivi Luona ◽  
Teija Tirri ◽  
Carl-Eric Wilen
Keyword(s):  
Molecular Weight ◽  
Tensile Tests ◽  
Resonance Spectroscopy ◽  
Alkyl Aryl ◽  
High Metal Content ◽  
Low Viscosity ◽  
Free Moisture ◽  
Ft Ir ◽  
End Capping ◽  
The Impact

This work explores the possibility of synthesizing moisture-curable silane-terminated poly(urethane-urea)s (SPURs) of low viscosity. First, NCO-terminated urethane prepolymers were prepared, followed by silane end-capping. The impact of polyol molecular weight and the ratio of isocyanate to polyol (NCO/OH) on viscosity and the properties of SPUR were examined. As alternatives to the organotin catalysts traditionally used for the polyurethane synthesis and curing processes, bismuth carboxylate catalysts were evaluated. In addition, the effect of organofunctional groups in the aminosilane structure (R1–NH–R2–Si(OR3)3), i.e., R1 (alkyl, aryl or trimethoxysilyl-propyl), the spacer R2 (α or γ) and alkyl group R3 (methyl or ethyl), was examined. The chemical and physical structures of the SPUR were investigated by nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FT-IR) and the mechanical properties were evaluated by tensile tests. The results reveal that silane-terminated, moisture-curable polyurethanes can be successfully synthesized and cured with bismuth carboxylate catalysts. SPUR exhibiting low viscosity, with adequate tensile strength and elongation can be prepared using environmentally benign bismuth carboxylate catalyst having a high metal content of 19%–21%, by utilizing secondary aminosilane end-cappers and an optimal combination of the polyol molecular weight and NCO/OH ratio.

Preparation and Properties of Regenerated Sisal Cellulose from a Homogeneous Solution

2014 ◽  
Vol 700 ◽  
pp. 265-269
Author(s):  
Fei Wang ◽  
Huan Liu ◽  
Ji Hua Li ◽  
Xiao Yi Wei ◽  
Yi Hong Wang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Homogeneous Solution ◽  
Regenerated Cellulose ◽  
Cellulose Ii ◽  
Optimal Conditions ◽  
Cellulose I ◽  
Natural Cellulose ◽  
Ft Ir ◽  
Ir Analysis ◽  
Application Fields

The sisal cellulose was dissolved in ILs under optimal conditions of 150°C and 400W. The structure of sisal cellulose was changed from cellulose I to cellulose II, accompanied with the decrease of crystallinity through XRD, FT-IR analysis. According to the result of GPC, molecular weight distribution became more uniformly and narrow. This is because intra-and inter-hydrogen bond existed in cellulose were destroyed during the dissolution process in ILs. And the regenerated cellulose possessed better properties than the former, which could broaden the application fields of natural cellulose.

Polarized microbeam FT-IR analysis of single fibers

1996 ◽  
Vol 54 ◽  
pp. 206-207
Author(s):  
Liling Cho ◽  
David L. Wetzel
Keyword(s):  
Molecular Orientation ◽  
Transition Point ◽  
Polymer Fibers ◽  
Single Fiber ◽  
Wire Grid ◽  
Polyester Fibers ◽  
Ft Ir ◽  
Ir Analysis ◽  
The Relationship ◽  
Wire Grid Polarizer

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

Synthesis and Evaluation of Levulinic Ester as Biodiesel Additives

2020 ◽  
Vol 71 (8) ◽  
pp. 21-26
Author(s):  
Elena-Emilia Oprescu ◽  
Cristina-Emanuela Enascuta ◽  
Elena Radu ◽  
Vasile Lavric
Keyword(s):  
Maximum Yield ◽  
Strength Distribution ◽  
Point Of View ◽  
Reaction Parameters ◽  
X Ray ◽  
Ethyl Levulinate ◽  
Ft Ir ◽  
Ir Analysis ◽  
Biodiesel Blend ◽  
Acid Strength Distribution

In this study, the SO42-/TiO2-La2O3-Fe2O3 catalyst was prepared and tested in the conversion of fructose to ethyl levulinate . The catalyst was characterized from the point of view of the textural analysis, FT-IR analysis, acid strength distribution, X-ray powder diffraction and pyridine adsorption IR spectra. The influence of the reaction parameters on the ethyl levulinate yield was study. The maximum yield of 37.95% in levulinate esters was obtained at 180 �C, 2 g catalyst and 4 h reaction time. The effect of ethyl levulinate addition to diesel-biodiesel blend in different rates, i.e, 0.5, 1, 2.5, 5 (w.t %) on density, kinematic viscosity and flash point was evaluated and compared with the European specification.

Applications of Algal Polysaccharides and Derivatives in Therapeutic and Agricultural Fields

2019 ◽  
Vol 25 (11) ◽  
pp. 1187-1199 ◽  
Author(s):  
Soukaina Bouissil ◽  
Guillaume Pierre ◽  
Zainab El Alaoui-Talibi ◽  
Philippe Michaud ◽  
C. El Modafar ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Wound Dressing ◽  
Chemical Processes ◽  
Bioactive Molecules ◽  
Present Review ◽  
Agricultural Fields ◽  
Low Molecular Weight ◽  
Molecular Weight Fractions ◽  
Algal Polysaccharides ◽  
Agricultural Fertilizer

Background: Recently, researchers have given more and more consideration to natural polysaccharides thanks to their huge properties such as stability, biodegradability and biocompatibility for food and therapeutics applications. Methods: a number of enzymatic and chemical processes were performed to generate bioactive molecules, such as low molecular weight fractions and oligosaccharides derivatives from algal polysaccharides. Results: These considerable characteristics allow algal polysaccharides and their derivatives such as low molecular weight polymers and oligosaccharides structures to have great potential to be used in lots of domains, such as pharmaceutics and agriculture etc. Conclusion: The present review describes the mains polysaccharides structures from Algae and focuses on the currents agricultural (fertilizer, bio-elicitor, stimulators, signaling molecules and activators) and pharmaceutical (wound dressing, tissues engineering and drugs delivery) applications by using polysaccharides and/or their oligosaccharides derivatives obtained by chemical, physical and enzymatic processes.

Formulation, Optimization,and Ex-Vivo Evaluation of Novel Lipid Carriers for Enhanced Transdermal Delivery of Hydroquinone

2020 ◽  
Vol 12 ◽  
Author(s):  
Shivani Verma ◽  
Sukhjinder Kaur ◽  
Lalit Kumar
Keyword(s):  
Ex Vivo ◽  
Skin Permeation ◽  
Topical Delivery ◽  
Gelling Agent ◽  
Minimum Size ◽  
Prolonged Release ◽  
Freeze Dried ◽  
Ft Ir ◽  
Ir Analysis ◽  
Skin Retention

Background: HQ is used for hyper-pigmentation treatment using conventional creams and gels. These formulations show various disadvantages like poor skin permeation, allergic reactions, and repeated use decreasing patient compliance. Objectives: The present work involved formulation, statistical optimization, and characterization of nanostructured lipid carriers (NLCs) for efficient topical delivery of hydroquinone (HQ) for hyperpigmentation treatment. Methods: The NLCs were optimized exploring Box–Behnken design (BBD) using three independent variables and two dependent variables. Formulation having the minimum size and maximum drug entrapment was considered as optimized formulation. Optimized formulation was evaluated for drug release followed by its freeze-drying. The freeze-dried formulation was subjected to differential scanning calorimetry (DSC) analysis, X-raydiffraction (XRD) analysis, and Fourier transform-infrared spectroscopy (FT-IR) analysis. Furthermore, NLCs based gel was prepared by using Carbopol 934 as a gelling agent. NLCs based gel was evaluated for skin permeation, skin retention, and skin distribution (through confocal microscopic analysis) using pig ear skin. Results: Optimized NLCs showed smaller particle size [(271.9 ± 9) nm], high drug entrapment [(66.4 ± 1.2) %], tolerable polydispersity index (PDI) (0.221 ± 0.012), and zeta potential [(-25.9± 1.2) mV]. The FT-IR analysis revealed excellent compatibility between HQ and other excipients. The Carbopol 934 gel containing NLCs showed high transdermal flux [(163 ± 16.2) μg/cm2/h], permeability coefficient (0.0326 ± 0.0016), and skin permeation enhancement ratio (3.7 ± 0.4) compared to marketed cream of HQ. The results of confocal microscopic (CLSM) analysis revealed the accumulation of optimized NLCs in the lower epidermal layers of skin. Conclusion: NLCs based gel was considered effective in the topical delivery of HQ to treat hyper-pigmentation due high skin permeation, skin retention, and prolonged release of HQ.

scholarly journals Biofoam of Spittlebug, Poophilus costalis (Walker): Preferential Sites, Temperature Regulation, Chemical Composition and Antimicrobial Activity

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 340
Author(s):  
Kitherian Sahayaraj ◽  
Balakrishnan Saranya ◽  
Samy Sayed ◽  
Loko Yêyinou Laura Estelle ◽  
Koilraj Madasamy
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
High Performance ◽  
Host Plants ◽  
Ground Level ◽  
College Campus ◽  
The Other ◽  
Mimosa Pudica ◽  
Ft Ir ◽  
Gas Chromatography Mass Spectroscopy

The foam produced by nymphs of Poophilus costalis on eleven different host plants belonging to eight families on St. Xavier’s College campus in India was studied over five months. The chemical composition and antimicrobial activity of these biofoams were investigated. The results revealed that P. costalis preferred Theporsia purpurea and Mimosa pudica for laying their eggs and producing foam, over the other tested plants. P. costalis produce their foam on either nodes or internodes on monocotyledons (30%) (p < 0.05), whereas on dicotyledons, they produce more foam on the stems (63.8%) than on the leaves (6.2%) (p < 0.01). The number of nymphs in each piece of foam from P. costalis varied from 1 to 3 (mean = 1.8 per plant). They produced their foam (5.7 to 45.2 cm) from the ground level on a plant. The length and breadth of a piece of foam ranged from 1.0 to 3.9 cm and 0.6 to 4.7 cm, respectively. The foam tended to be cooler than the environment. Qualitative profiling showed that the foam consists of carbohydrates, including maltose; trypsin; amino acids; protease. The foam was also analyzed using a spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), gas chromatography–mass spectroscopy (GC-MS), and high-performance liquid chromatography (HPLC). The antimicrobial activity of the biofoam was the greatest against Staphylococcus aureus, the growth of which was reduced by 55.9 ± 3.9%, suggesting that the foam could be used as an antimicrobial product. However, no activities were observed against Fusarium oxysporum and Candida albicans.

Impact of Chemical Modification on the Physical and Mechanical Properties of Tropical Wood Material

2012 ◽  
Vol 576 ◽  
pp. 314-317
Author(s):  
Sinin Hamdan ◽  
M. Saiful Islam
Keyword(s):  
Mechanical Properties ◽  
Diazonium Salt ◽  
Treated Wood ◽  
Coupling Reaction ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Ft Ir ◽  
Ir Analysis ◽  
D Values ◽  
Benzene Diazonium

Five types of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physical and mechanical properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through FT-IR analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. The modified wood samples had higher hardness (Shore D) values compared to that of the control ones.

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