scholarly journals Gracilaria gracilis (Gracilariales, Rhodophyta) from Dakhla (Southern Moroccan Atlantic Coast) as Source of Agar: Content, Chemical Characteristics, and Gelling Properties

Marine Drugs ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. 672
Author(s):  
Zahira Belattmania ◽  
Sanaa Bhaby ◽  
Amal Nadri ◽  
Khaoulaa Khaya ◽  
Fouad Bentiss ◽  
...  
Keyword(s):  
Atlantic Coast ◽  
13C Nmr Spectroscopy ◽  
Sulfated Polysaccharide ◽  
Alkaline Pretreatment ◽  
Gel Properties ◽  
Gracilaria Gracilis ◽  
Gelling Properties ◽  
Notable Increase ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Agar is a sulfated polysaccharide extracted from certain marine red algae, and its gel properties depend on the seaweed source and extraction conditions. In the present study, the seaweed Gracilaria gracilis (Gracilariales, Rhodophyta) from Dakhla (Moroccan Atlantic Coast) was investigated for its agar content, structure, and gel properties. The agar yields of G. gracilis were 20.5% and 15.6% from alkaline pretreatment and native extraction, respectively. Agar with alkaline pretreatment showed a better gelling property supported by higher gel strength (377 g·cm−2), gelling (35.4 °C), and melting (82.1 °C) temperatures with a notable increase in 3,6-anhydro-galactose (11.85%) and decrease in sulphate (0.32%) contents. The sulfate falling subsequent to alkaline pretreatment was verified through FT-IR spectroscopy. The 13C NMR spectroscopy showed that alkaline-pretreated agar has a typical unsubstituted agar pattern. However, native agar had a partially methylated agarose structure. Overall, this study suggested the possibility of the exploitation of G. gracilis to produce a fine-quality agar. Yet, further investigation may need to determine the seasonal variability of this biopolymer according to the life cycle of G. gracilis.

Spectroscopic Evaluation of the Effect of a Red Microalgal Polysaccharide on Herpes-Infected Vero Cells

2003 ◽  
Vol 57 (4) ◽  
pp. 390-395 ◽  
Author(s):  
Mahmoud Huleihel ◽  
Marina Talyshinsky ◽  
Yelena Souprun ◽  
Vitaly Erukhimovitch
Keyword(s):  
Ir Spectroscopy ◽  
Sugar Content ◽  
Antiviral Agent ◽  
Vero Cells ◽  
Sulfated Polysaccharide ◽  
Sugar Accumulation ◽  
Infected Cells ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The sulfated polysaccharide obtained from a species of red microalga has proved to be a potent antiviral agent against various members of the herpes family. In the present study, we used microscopic Fourier transform infrared spectroscopy (FT-IR) to investigate differences between normal cells, those infected with herpes viruses, and infected cells treated with red microalgal polysaccharide. FT-IR enables the characterization of cell or tissue pathology based on characteristic molecular vibrational spectra of the cells. The advantage of microscopic FT-IR spectroscopy over conventional FT-IR spectroscopy is that it facilitates inspection of restricted regions of cell cultures or tissue. Our results showed significant spectral differences at early stages of infection between infected and noninfected cells, and between infected cells treated with the polysaccharide and those not treated. In infected cells, there was an impressive decrease in sugar content and a considerable increase in phosphate levels in conjunction with the infection progress. Our results also proved that sugars penetrated and accumulated inside cells treated with the red microalgal polysaccharide. These could have been sugar fragments of low molecular weight present in the polysaccharide solution, despite purification by dialysis. Such sugar accumulation might be responsible for a breakdown in the internal steps of the viral replication cycle.

scholarly journals Ulvan as A New Trend in Agriculture, Food Processing and Medicine

2020 ◽  
pp. 47-54
Author(s):  
Hadear Hanie Amin
Keyword(s):  
Food Processing ◽  
Gel Permeation Chromatography ◽  
Sulfated Polysaccharide ◽  
Hot Water ◽  
Human Pathogen ◽  
Hot Water Extraction ◽  
Gel Permeation ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

In this work the researcher is looking for natural, new, safe, cheap and available compounds that can be used as antimicrobial and antioxidant in the medical and agricultural fields. A sulfated polysaccharide, Ulvan was extracted from Ulva lactuca and purified by cold or hot water-extraction and ethanol-precipitation with yield = 5:10% (w-w). Its appearance and touch like gel. Characterization of active groups of Ulvan was achieved by FT-IR spectroscopy, its content of sulfate = 3.998% (w-w) was determined by Ion Chromatography (IC), its molecular weight = 532.221 Kilo Daltons was determined by Gel permeation chromatography, its thermal stability was evaluated by DSC-TGA, its viscosity = 18 was determined by viscometer apparatus and its antimicrobial activity was studied against human, plant, animal, fish and poultry pathogens. Ulvan showed antioxidant activity with IC50 = 3.04 mg/ml. Its biological activity as an antioxidant and antimicrobial may be a good indication for the use of Ulvan against various pathogens as a preservative in food processing and cosmetics and as antioxidant and antimicrobial in medicine against human pathogen.

Antioxidant Activity of Sulfated Polysaccharide Extract from Green Seaweed (Caulerpa lentillifera) Makassar, Indonesia

2020 ◽  
Vol 840 ◽  
pp. 214-220
Author(s):  
Ilmi Fadhilah Rizki ◽  
Ellya Sinurat ◽  
Sofa Fajriah ◽  
Endang Saefudin
Keyword(s):  
Antioxidant Activity ◽  
Crude Extract ◽  
Biological Activities ◽  
Sulfated Polysaccharide ◽  
Total Carbohydrate ◽  
Caulerpa Lentillifera ◽  
Green Seaweed ◽  
Ft Ir ◽  
Crude Polysaccharide ◽  
Ft Ir Spectroscopy

Caulerpa lentillifera belong to Caulerpa genus which is commonly found in tropical and subtropical water. The biggest constituent of seaweed is polysaccharide that has some biological activities as a potential medicine. Therefore, this research aimed to extract and evaluate the antioxidant activity from Caulerpa lentillifera polysaccharide. The extraction was carried out by using water extraction. First, the sample was added with ethanol and soaked overnight at room temperature. On the following day, the sample was added with aquades and put in a water bath at 75°C for three hours. After that, ethanol was added to precipitate the extract. The crude polysaccharide extract percent yield obtained 4.16 %. The crude extract purified by using a column with DEAE-Sepharose with percent yield obtained 14.8 %. Both crude and pure extracts were characterized by analyzing the total carbohydrate and sulfate by using spectrophotometer, functional group by using FT-IR spectroscopy and sugar component by using HPLC. Antioxidant activity was analyzed by using the FRAP method for both crude and pure extract. Moreover, the polysaccharide crude extract gives higher antioxidant activity than the purified extract.

scholarly journals Spectroscopic Characterization and Gel Properties of Agar from Two Gelidium Species from the Atlantic Coast of Morocco

2021 ◽  
Vol 11 (5) ◽  
pp. 12642-12652
Keyword(s):  
Atlantic Coast ◽  
13C Nmr Spectroscopy ◽  
Spectroscopic Characterization ◽  
Rheological Characterization ◽  
Gel Properties ◽  
Melting Temperatures ◽  
Agar Yield ◽  
Yield And Quality

The commercial value of agar in the phycocolloid market depends mostly on the agar yield and quality. The present study investigates the agar content and characterization of two Gelidiales Gelidium corneum and Gelidium microdon from the Moroccan Atlantic coast. Spectroscopic and rheological characterization of extracted agar without and with alkali pretreatments were evaluated. The highest agar yield was detected for mild alkaline pretreatment (N2CO3). The native agar content in G. corneum was 16.21%, while those pretreated with NaOH and N2CO3 ranged from 6.2 to 20.50 %. The agar yields of G. microdon showed values of 12.23%, 14.87%, and 17.73%, corresponding respectively to native agar, NaOH, and Na2CO3 pretreatments. Agar with alkali pretreatments depicted the better gelling property with higher gel strength and elevated gelling and melting temperatures. 13C NMR spectroscopy showed that G. Corneum has a typical unsubstituted and weakly methylated agar pattern. However, G. microdon revealed the presence of methyl and sulfate groups at the C4 of 4-O-L-galactose residues, responsible for the low gelling ability of the native agar. The decline of sulfate groups after alkali pretreatments were proved by FTIR spectroscopy. This study demonstrates that G. microdon produces a quality of agar similar to that of G. corneum. Thus G. microdon could be regarded as a potential additional source of agar industry in Morocco.

scholarly journals The Preparation, Thermal Properties, and Fire Property of a Phosphorus-Containing Flame-Retardant Styrene Copolymer

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 127 ◽  
Author(s):  
Yu Sun ◽  
Yazhen Wang ◽  
Li Liu ◽  
Tianyuan Xiao
Keyword(s):  
Thermal Properties ◽  
Thermogravimetric Analysis ◽  
Flame Retardant ◽  
Oxygen Index ◽  
Limiting Oxygen Index ◽  
Chemical Structures ◽  
1H Nuclear Magnetic Resonance ◽  
Phosphorus Containing ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

A 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) acrylate, (6-oxidodibenzo [c,e][1,2] oxaphosphinin-6-yl) methyl acrylate (DOPOAA), has been prepared. Copolymers of styrene (St) and DOPOAA were prepared by emulsion polymerization. The chemical structures of copolymers containing levels of DOPOAA were verified using Fourier transform infrared (FT-IR) spectroscopy and 1H nuclear magnetic resonance (1H-NMR) spectroscopy. The thermal properties and flame-retardant behaviors of DOPO-containing monomers and copolymers were observed using thermogravimetric analysis and micro calorimetry tests. From thermogravimetric analysis (TGA), it was found out that the T5% for decomposition of the copolymer was lower than that of polystyrene (PS), but the residue at 700 °C was higher than that of PS. The results from micro calorimetry (MCC) tests indicated that the rate for the heat release of the copolymer combustion was lower than that for PS. The limiting oxygen index (LOI) for combustion of the copolymer rose with increasing levels of DOPOAA. These data indicate that copolymerization of the phosphorus-containing flame-retardant monomer, DOPOAA, into a PS segment can effectively improve the thermal stability and flame retardancy of the copolymer.

Multiscale exploration of hydrocarbons adsorption and hopping through the ZSM-5 channels - from Monte Carlo modelling to experiment

2021 ◽  
Author(s):  
Maciej Strzempek ◽  
Karolina A. Tarach ◽  
Kinga Góra-Marek ◽  
Fernando Rey ◽  
Miguel Palomino ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Ir Spectroscopy ◽  
Aliphatic Hydrocarbons ◽  
Adsorption Studies ◽  
Ft Ir ◽  
Gravimetric Adsorption ◽  
Hydrocarbons Adsorption ◽  
Ft Ir Spectroscopy

Abstract In this article the results of the statistical MC modelling corroborated by the FT-IR spectroscopy and gravimetric adsorption studies of the low aliphatic hydrocarbons in ZSM-5 (Si/Al =28 or...

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