Degraded polysaccharides from Porphyra haitanensis: purification, physico-chemical properties, antioxidant and immunomodulatory activities was written by Huo, Yun-Feng;Li, Yin-Ting;Xia, Wei;Wang, Chong;Xie, Yuan-Yuan;Wang, Yan-Bo;Zhou, Tao;Fu, Ling-Lin. And the article was included in Glycoconjugate Journal in 2021.COA of Formula: C16H22O11 This article mentions the following:
Abstract: To explore effect of the structural properties of porphyra haitanensis polysaccharide on its biol. activity, degraded porphyra polysaccharides were separated and purified by Cellulose DEAE-52 and Sephadex G-100 chromatog., obtaining three purified components (P1, P2 and P3). All the three components were sulfate polysaccharides containing the repeating units of → 3 β-D-galactose 3,6-anhydro-α-L-galactose 1 →, and → 3 β-D-galactose 1 → 4 α-L-galactose-6-S 1 →, and → 3 6-O-methyl-β-D-galactose 1 → 4 3,6-anhydro-α-L-galactose 1 →. The mol. weight of the three fractions was measured to be 300.3, 130.4 and 115.1 kDa, resp. Their antioxidant activity was investigated by the determination of the free radical scavenging effect and ferric reducing power. It was found that P1, P2 and P3 possessed marked antioxidant activity. It was also found that they appreciably enhanced the proliferation, phagocytic ability and nitric oxide secretion in RAW264.7 cells. Lower mol. weight and higher sulfate content were beneficial to bioactivities of P. haitanensis polysaccharides. Overall, P2 and P3 possess superior immuno-modulatory activity to that of P1 and PHP. Thus, the current work will provide the basis for the better utilization of P. haitanensis to develop the related functional foods. Graphical abstract: [graphic not available: see fulltext]. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4COA of Formula: C16H22O11).
(2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. COA of Formula: C16H22O11
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics