Structural Features and Antiviral Activity of Sulphated Fucans from the Brown Seaweed Cystoseira Indica

Abstract

Natural compounds offer interesting pharmacological perspectives for antiviral drug development. In this study, we have analysed sulphated-fucan-containing fractions isolated from the brown seaweed Cystoseira indica. The crude water extract (CiWE) and the main fraction (CiF3) obtained by anion exchange chromatography had potent antiviral activity against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) without cytotoxicity for Vero cell cultures. Furthermore, they had no direct inactivating effect on virions in a virucidal assay, and lacked anticoagulant activity. The mode of action of these compounds could be mainly ascribed to an inhibitory effect on virus adsorption. Chemical, chromatographic and spectroscopic methods showed that the major polysaccharide had an apparent molecular mass of 35 kDa and contained a backbone of alpha-(1 --> 3)-linked fucopyranosyl residues substituted at C-2 with fucopyranosyl and xylopyranosyl residues. This sulphated fucan, considered the active principle of the C. indica water extract, also contained variously linked xylose and galactose units and glucuronic acid residues. Sulphate groups, if present, are located mostly at C-4 of (1 --> 3)-linked fucopyranosyl units, and appeared to be very important for the anti-herpetic activity of this polymer.

Algal Polysaccharides, Novel Applications and Outlook

“…The mechanism of anti-viral activities of fucoidan is to inhibit viral sorption so as to inhibit viral-induced syncytium formation (Mandal et al 2007). Sulphate is necessary for the antiviral activity and sulphate located at C-4 of (1-3)-linked fucopyranosyl units appears to be very important for the anti-herpetic activity of fucoidan (Mandal et al 2007).…”

“…Sulphate is necessary for the antiviral activity and sulphate located at C-4 of (1-3)-linked fucopyranosyl units appears to be very important for the anti-herpetic activity of fucoidan (Mandal et al 2007). Some anti-viral properties of sulphated fucans have also been characterised, for example inhibition of infection of human immunodeficiency virus (HIV), Herpes Simplex Virus (HSV) (Iqbal et al 2000;Mandal et al 2007;Witvrouw and DeClercq 1997), poliovirus III, adenovirus III, ECH06 virus, coxsackie B3 virus, coxsackie A16 (Li et al 1995), cytomegalovirus and bovine viral diarrhea virus (Iqbal et al 2000).…”

Application of Gas Chromatography to Exuded Organic Matter Derived from Macroalgae

“…Mucopolysaccharides which are known as extracellular carbohydrates have been analyzed using GC or GCMS after some purification treatments (Lee et al, 2004;Mandal et al, 2007;Karmakar et al, 2010;Rioux et al, 2010;Stephanie et al, 2010). On the other hand, direct analysis for carbohydrates released into ambient seawater is limited (Wada et al, 2007;2008).…”

Bioactive Compounds and Properties of Seaweeds—A Review

“…Although brown seaweed is also available in supplement form, there is limited scientific evidence to support the use of brown seaweed supplements. Brown seaweeds show antiviral activities from sulfated fucans from C. indica against herpes simplex virus 1 and 2 without cytotoxicity for vero cell cultures [109]. Stypoldione, acytotoxiccompounds derived from Stypodiumzonale, inhibits microtubule polymerizationand sperm motility [110].…”