Structure and anticancer activity in vitro of sulfated galactofucan from brown alga Alaria angusta

• Published in: Carbohydrate polymers Vol. 132; pp. 118 - 125
• Main Authors: Menshova, Roza V., Anastyuk, Stanislav D., Ermakova, Svetlana P., Shevchenko, Natalia M., Isakov, Vladimir I., Zvyagintseva, Tatiana N.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 05.11.2015
• Subjects: Anticancer activity; Antineoplastic Agents - chemistry; Antineoplastic Agents - isolation & purification; Antineoplastic Agents - pharmacology; Brown alga; Cell Line, Tumor; Depolymerization; Fucoidan; Glucans - chemistry; Glucans - isolation & purification; Glucans - pharmacology; Humans; Neoplasms - drug therapy; Phaeophyceae - chemistry; Polysaccharides - chemistry; Polysaccharides - isolation & purification; Polysaccharides - pharmacology; Structure; Depolymerization; Brown alga; Fucoidan; Structure; Anticancer activity
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2015.06.020

•Structure of galactofucan AaF3 from Alaria angusta was investigated.•AaF3 was depolymerized, and structure of products were studied.•Autohydrolysis of AaF3 leaded to a formation 1,3-linked 4-sulfated fucan.•AaF3 inhibited colony formation HT 29 and T-47D cell lines. Laminaran and three fractions of fucoidan were isolated from brown alga Alaria angusta. The laminaran AaL was characterized as a typical 1,3;1,6-β-D-glucan (ratio of bonds 1,3:1,6=10:1). Fucoidans AaF1 and AaF2 are sulfated heteropolysaccharides, containing fucose, galactose, mannose and xylose. The fraction AaF3 is sulfated and acetylated galactofucan with the main chain represented by a repeating unit →3)-α-L-Fucp-(2,4-SO3−)-(1→. According the data of methylation analysis, AaF3 contains mainly 1,3-linked fucose, less 1,4-linked and 1,4,6-linked galactose residues. The autohydrolysis (37°C) of fucoidan AaF3 allowed to obtain selectively 2-desulfaled polysaccharide fraction, built up of fucose only, and low molecular weight (LMW) fraction. The negative-ion tandem mass spectrometry of LMW fraction, further hydrolyzed by acid hydrolysis identified the following fragments: Gal-2-SO3−-(1→4)-Gal, Gal-4-SO3−-(1→4)-Gal, Gal-(1→2)-Gal-4-SO3−, Fuc-2-SO3−-(1→4)-Gal, Gal-2-SO3−-(1→3)-Fuc-(1→3)-Fuc, Fuc-2-SO3−-(1→3)-Fuc-(1→4)-Gal. The laminaran AaL and the fucoidan AaF3 exhibited no cytotoxicity in vitro for HT 29, T-47D, and SK-MEL-28 cell lines. The AaF3 fraction suppressed colony formation of HT 29 and T-47D cells, AaL—only HT 29 cells.