scholarly journals Characterization of kappa-carageenan from the red alga Kappaphycus striatum

2020 ◽  
Vol 18 (2) ◽  
pp. 321-329
Author(s):  
Le Dinh Hung ◽  
Dang Thi Huong
Keyword(s):  
Average Molecular Weight ◽  
Red Alga ◽  
Absorption Bands ◽  
Material Source ◽  
Nmr Spectrum ◽  
Important Species ◽  
Methyl Proton ◽  
Anomeric Carbon ◽  
Kappa Carrageenan

The red alga Kappaphycus striatum is an economically important species and extensively cultivated in Vietnam as a material source for carrageenan production. To evaluate carrageenan quality, the characterization of carrageenan extracted from this alga was investigated. As a result, chemical composition of carrageenan consists of 32.4% of 3,6 anhydrogalactose and 24.3% of sulfate. Gelling and metling temperatures are 34.4oC and 55.6oC, respectively. Gel strength of 1.5% is 615 g/cm2 and average molecular weight is about 267 kDa. Furthermore, FT-IR spectrum showed intense absorption bands at 930 cm-1 and 850 cm-1 that attributed to 1,4-linked 3,6 anhydro-α-D-galactose and 1,3-linked β-D-galactose-4-sulfate of kappa-carrageenan, respectively. 13C NMR spectrum indicated the signals for anomeric carbon of β-D-galactose-4-sulfate at 102.6 ppm and anomeric carbon of 3,6-anhydro-α-D-galactose at 95.3 ppm. 13H NMR spectrum showed peak signals at 3.57 ppm and 5.1 ppm that corresponds with O-methyl proton of 1,3-linked 6-O-methyl-D-galactose and α-anomeric proton of 3,6 anhydro-α-D-galactose residues, respectively. The results show that the carrageenan from the red alga Kappaphycus striatus is kappa-carrageenan with the repeating disaccharide unit consisting of 1,3-linked 6-O-methylated, β-D-galactose-4-sulfate and 1,4-linked 3,6 anhydro-α-D-galactose and did not contain iota-carrageenan. Therefore, this alga may promise to be a good source for carrageenan production for application in food or medicine.

Characterization of aspen exploded wood lignin

1982 ◽  
Vol 60 (18) ◽  
pp. 2372-2382 ◽  
Author(s):  
R. H. Marchessault ◽  
Suzanne Coulombe ◽  
Hiromichi Morikawa ◽  
Danielle Robert
Keyword(s):  
Room Temperature ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Aryl Ether ◽  
Weight Average Molecular Weight ◽  
Nmr Spectrum ◽  
Typical Composition ◽  
Moist Steam ◽  
C Nmr

Exploded wood lignin (EXWL) was extracted from moist steam hydrolysed aspen (Populustremuloides) wood using methanol. The lignin was examined by elemental analysis, gel permeation chromatography, infrared spectroscopy, proton and 13C nmr. The observed nmr spectra were compared with those of aspen milled wood lignin (MWL). Typical composition of the material is C9H9.2O2.7(OCH3)1.1 Assignment of all the signals in the nmr spectrum led to the conclusion that the explosion process causes cleavage of the β-aryl-ether bond. The weight average molecular weight was found to be 1700–1900 and the polydispersity 2.6. The finely divided exploded wood was soluble in 90% methanol/water mixtures to well beyond 20% by weight at room temperature.

scholarly journals Synthesis, structure and characterization of a new cadmium(II) iodide containing a tetradentate tripodal amine

2014 ◽  
Vol 10 (5) ◽  
pp. 2728-2736 ◽  
Author(s):  
Kamel Kaabi ◽  
Valeria Ferretti ◽  
Frederic Lefebvre ◽  
Cherif Ben Nasr
Keyword(s):  
Infrared Spectroscopy ◽  
Dft Calculations ◽  
Absorption Bands ◽  
Nmr Spectrum ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Cp Mas Nmr ◽  
13C Cp Mas Nmr ◽  
Distorted Trigonal Bipyramidal

A cadmium(II) iodide compound of the [Cd(L)I]I series, with L = tris(2-aminoethyl)amine, is synthesized and characterized. X-ray structural study shows that the title compound has a slightly distorted trigonal bipyramidal environment where the CdN4I chromophore is bounded by N atoms of L and one iodide. In the structural arrangement, the [Cd(L)I]+ cationic complexes are interconnected via N-H···I hydrogen bonds generated by the uncoordinated I iodide anions to form layers parallel to the (a, c) plane. The 13C CP-MAS NMR spectrum is discussed and the vibrational absorption bands were identified by infrared spectroscopy and DFT calculations.

scholarly journals Characterization of Beeswax, Candelilla Wax and Paraffin Wax for Coating Cheeses

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 261
Author(s):  
Adolfo Bucio ◽  
Rosario Moreno-Tovar ◽  
Lauro Bucio ◽  
Jessica Espinosa-Dávila ◽  
Francisco Anguebes-Franceschi
Keyword(s):  
Physical And Mechanical Properties ◽  
Tensile Tests ◽  
Paraffin Wax ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Dimensional Changes ◽  
Ductile Behavior ◽  
Candelilla Wax

A study on the physical and mechanical properties of beeswax (BW), candelilla wax (CW), paraffin wax (PW) and blends was carried out with the aim to evaluate their usefulness as coatings for cheeses. Waxes were analyzed by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetry (DSC), permeability, viscosity, flexural and tensile tests and scanning electron microscopy. Cheeses were coated with the waxes and stored for 5 weeks at 30 °C. Measured parameters were weight, moisture, occurrence and degree of fractures, and dimensional changes. The crystal phases identified by XRD for the three waxes allowed them to determine the length of alkanes and the nonlinear compounds in crystallizable forms in waxes. FTIR spectra showed absorption bands between 1800 and 800 cm−1 related to carbonyls in BW and CW. In DSC, the onset of melting temperature was 45.5 °C for BW, and >54 °C for CW and PW. Cheeses coated with BW did not show cracks after storage. Cheeses coated with CW and PW showed microcraks, and lost weight, moisture and shrunk. In the flexural and tensile tests, BW was ductile; CW and PW were brittle. BW blends with CW or PW displays a semi ductile behavior. Cheeses coated with BW blends lost less than 5% weight during storage. The best waxes were BW and the blends.

scholarly journals Ultrasound-assisted depolymerization of kappa-carrageenan and characterization of degradation product

2021 ◽  
pp. 105540
Author(s):  
Mariel G. Tecson ◽  
Lucille V. Abad ◽  
Virgilio D. Ebajo ◽  
Drexel H. Camacho
Keyword(s):  
Degradation Product ◽  
Ultrasound Assisted ◽  
Kappa Carrageenan

scholarly journals Plasma proteomics of green turtles (Chelonia mydas) reveals pathway shifts and potential biomarker candidates associated with health and disease

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
David P Marancik ◽  
Justin R Perrault ◽  
Lisa M Komoroske ◽  
Jamie A Stoll ◽  
Kristina N Kelley ◽  
...  
Keyword(s):  
Chelonia Mydas ◽  
Sea Turtle ◽  
Protein Abundance ◽  
Plasma Samples ◽  
Important Species ◽  
Green Turtles ◽  
Rehabilitation Programs ◽  
Potential Biomarker ◽  
Health And Disease

Abstract Evaluating sea turtle health can be challenging due to an incomplete understanding of pathophysiologic responses in these species. Proteome characterization of clinical plasma samples can provide insights into disease progression and prospective biomarker targets. A TMT-10-plex-LC–MS/MS platform was used to characterize the plasma proteome of five, juvenile, green turtles (Chelonia mydas) and compare qualitative and quantitative protein changes during moribund and recovered states. The 10 plasma samples yielded a total of 670 unique proteins. Using ≥1.2-fold change in protein abundance as a benchmark for physiologic upregulation or downregulation, 233 (34.8%) were differentially regulated in at least one turtle between moribund and recovered states. Forty-six proteins (6.9%) were differentially regulated in all five turtles with two proteins (0.3%) demonstrating a statistically significant change. A principle component analysis showed protein abundance loosely clustered between moribund samples or recovered samples and for turtles that presented with trauma (n = 3) or as intestinal floaters (n = 2). Gene Ontology terms demonstrated that moribund samples were represented by a higher number of proteins associated with blood coagulation, adaptive immune responses and acute phase response, while recovered turtle samples included a relatively higher number of proteins associated with metabolic processes and response to nutrients. Abundance levels of 48 proteins (7.2%) in moribund samples significantly correlated with total protein, albumin and/or globulin levels quantified by biochemical analysis. Differentially regulated proteins identified with immunologic and physiologic functions are discussed for their possible role in the green turtle pathophysiologic response and for their potential use as diagnostic biomarkers. These findings enhance our ability to interpret sea turtle health and further progress conservation, research and rehabilitation programs for these ecologically important species.

Some inequalities for moments and coefficients of variation for a large class of probability functions

1979 ◽  
Vol 16 (3) ◽  
pp. 665-670 ◽  
Author(s):  
Burt V. Bronk
Keyword(s):  
Large Class ◽  
Average Molecular Weight ◽  
Empirical Measure ◽  
Number Average Molecular Weight ◽  
Positive Real ◽  
Coefficients Of Variation ◽  
Probability Densities ◽  
Rigorous Bounds ◽  
Illustrative Application

Some inequalities for moments and coefficients of variation of probability densities over the positive real line are obtained by means of simple geometrical relationships. As an illustrative application rigorous bounds are obtained for the ratio of weight average to number average molecular weight for a large class of distributions of macromolecules, giving a more precise characterization of this empirical measure of heterogeneity.

Ultrastructural characterization of a pigment mutant of the red alga Palmaria palmata

1984 ◽  
Vol 62 (6) ◽  
pp. 1101-1107 ◽  
Author(s):  
C. M. Pueschel ◽  
J. P. van der Meer
Keyword(s):  
Red Alga ◽  
Palmaria Palmata ◽  
Wild Type ◽  
Ultrastructural Examination ◽  
Dark Treatment ◽  
Prolamellar Bodies ◽  
Ultrastructural Characterization ◽  
Wild Type Control

Ultrastructural examination of a green-pigmented mutant of the red alga Palmaria palmata (L.) O. Kuntze revealed unusual features of the chloroplasts. Encircling peripheral thylakoids, characteristic of the wild-type plastids and florideophyte plastids generally, were lacking. Parallel evenly spaced thylakoids occurred in groups, leaving large volumes of thylakoid-free stroma. Irregularly shaped, electron-dense inclusions with an amorphous substructure and diameters up to 3 μm occurred in some plastids. Cells of the sporeling holdfasts contained structures resembling prolamellar bodies. Attempts to induce formation of prolamellar bodies in blades by dark treatment for 5 weeks were unsuccessful. However, some plastids did develop highly corrugated thylakoids with the crests of one thylakoid apposed to the troughs of the adjacent thylakoid. Thylakoid morphology of the wild-type control was not altered by the absence of light.

Characterization of .kappa.-carrageenan gels used for immobilization of Bacillus firmus

1991 ◽  
Vol 7 (6) ◽  
pp. 516-525 ◽  
Author(s):  
Seung Hyeon Moon ◽  
Satish J. Parulekar
Keyword(s):  
Bacillus Firmus ◽  
Kappa Carrageenan
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