Chemical Characterization of Agar from an Agarophyte Grown in the Lagoon of Binh Tri Thien (Vietnam)

Truong, H. H.; Lesecq, P.; Karamanos, I.; Quang, Y. Vo; Christiaen, D.

doi:10.1515/botm.1988.31.4.289

Cited by 6 publications

(3 citation statements)

References 19 publications

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“…The sulphate ester of C-6 linkage was observed at 880 cm -1 in G. usmanghanii, in G. foliifera it appeared at 885 cm -1 in C. compressa this peak appeared at 895 cm -1 and in H. musciformis this absorption was appeared at 865 cm -1 . The -D-galactose pyranose residues are well known agar peak according to the literature survey (Troung et al 1988).The additional peaks 830, 846 and 821 cm -1 were noticed in the spectrum of rest of the samples of G. foliifera, C. compressa and H. musciformis which is the representative peak of sulphate ester C-2 link absorptions. The linkage of C-S absorption of polysaccharides has been reported in literature in the region of 670 -770 cm -1 .…”

Section: Resultsmentioning

confidence: 78%

Fourier transform infrared (FT-IR) spectroscopic investigations of four agarophytes from northern Arabian sea

2019

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The fresh specimens of Champia compressa Harvey, Gelidium usmanghanii Afaq-Husain and M. Shameel, Gracilaria foliifera (Forsskål) Børgesen and Hypnea musciformis (Wulfen) J. V. Lamouroux, were collected from the coastal areas of Karachi (Pakistan) and their yield of agar was observed. With preextraction technique the percentage of algal yield was found to range from 13 to 28%. High quality gel strength was determined by modulus of elasticity i.e. (550 – 612g/cm2) and 1090 kPa and extraction time was 2 hrs. The structure of agar and agar contents were investigated by FT-IR spectroscopy for the first time from Pakistan. The results revealed some interesting characters (non sulphated β-D galacto pyranose residues, 3,6 anhydro galactose vibration), which were not reported earlier.

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Section: Resultsmentioning

confidence: 78%

Fourier transform infrared (FT-IR) spectroscopic investigations of four agarophytes from northern Arabian sea

2019

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“…Agar is known to be a mixture of molecules having a structure of the idealized agarose molecules and partially modified agarose substituted by sulfate, methoxyl and 4,6-0-(1-carboxyethylidene)-D-galactose at various positions (Araki, 1966;. The chemical heterogeneity of agar has been determined using anion exchange chromatography, sequential solvent extraction, 3 C -NMR and IR spectrophotometry (Minghou et al, 1985(Minghou et al, , 1988Yang & Liu, 1988;Truong et al, 1988;Lahaye et al, 1986;.…”

Section: Introductionmentioning

confidence: 99%

Seasonal changes in the chemical and gelling characteristics of agar from Gracilaria verrucosa collected in Turkey

Yenig�l

1993

Hydrobiologia

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The chemical and gelling properties of agar from G. verrucosa collected from Izmit bay in Turkey at different months of the year were studied. Purification of agar was performed by using amylase treatment and isopropyl alcohol precipitation. The phycocolloid content was between 24.0-43.0% of the algal dry weight and was maximum in summer collected algae. Relative total sulfate and 3,6-anhydrogalactose content in the agar were determined from the ratios of infrared spectroscopy band intensities at 1250/ 2920 cm -and 930/2920 cm -1, respectively. 3,6-anhydrogalactose and sulfate contents were the highest

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“…Agars having a double methylation pattern have been reported only recently (Lahaye et al, 1986 ;Truong et al, 1988), and in these cases the level of methylation on 0-2 of the 3,6-anhydro-L-galactose residues has been low . However, strong gels were obtained from other extracts following alkali treatment, and in particular we note a strong gel from the `agar' from Curdiea coriacea, which has doubly methylated biose units .…”

Section: Conclusonsmentioning

confidence: 99%

Agaroids from New Zealand members of the Gracilariaceae (Gracilariales, Rhodophyta) ? a novel dimethylated agar

Furneaux¹,

Miller²,

Stevenson³

1990

Hydrobiologia

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Polysaccharide extracts from four New Zealand members of the Gracilariaceae have been characterized by 13 C-NMR spectroscopy and GLC analysis of alditol acetate derivatives prepared using a new double hydrolysis-reduction procedure . All were based on variously substituted repeating disaccharide units of agarobiose and _< 20 % of its `precursor' containing L-galactose-6-sulfate . Gracilaria truncata yielded a firm gelling agar with 67 % methylation on the 6-position of the D-galactose residues . The other extracts belong to a new class of agar molecules having methylation on both the 6-position of the D-galactose units and the 2-position of the L-sugar units . The Curdiea coriacea polysaccharide displayed this double methylation almost completely (>_ 96 %) ; the alkali-modified polymer thus had only two free hydroxygroups per disaccharide repeat unit, yet still gave a firm gel . The Curdiea flabellata and Melanthalia abscissa extracts had this double methylation pattern but to a lesser extent, and additional xylosyl branch units on up to 18 % of the repeating disaccharide units .

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Chemical Characterization of Agar from an Agarophyte Grown in the Lagoon of Binh Tri Thien (Vietnam)

Cited by 6 publications

References 19 publications

Fourier transform infrared (FT-IR) spectroscopic investigations of four agarophytes from northern Arabian sea

Fourier transform infrared (FT-IR) spectroscopic investigations of four agarophytes from northern Arabian sea

Seasonal changes in the chemical and gelling characteristics of agar from Gracilaria verrucosa collected in Turkey

Agaroids from New Zealand members of the Gracilariaceae (Gracilariales, Rhodophyta) ? a novel dimethylated agar

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