An exopolysaccharide EPSNC2 produced from marine Streptomyces hirsutus NRC2018 which isolated from marine sediments at North Coast, Egypt with accession number MK050544. EPSNC2 was a β-type heteropolysaccharide contained uronic acid (72.73 %) and no sulfate with overall average molecular weight (Mw) 4.25×105 g/mole. The monosaccharide composition was glucuronic : galacturonic : glucose : mannose : arabinose with molar ratio 1.2 : 0.6 : 0.1 : 0.2 : 0.1, respectively. EPSNC2 was subjected to perform antioxidant, anticancer and antiviral tests in vitro showed high DPPH free radical scavenging activity whereas, the maximum antioxidant activity was 95.9 % at 1500 µg/ml after 120 min and the IC50 value was 158.5 µg/mL. Also, EPSNC2 had ability to scavenge H2O2 and the maximum activity was 75.6 % with estimated IC50 value 501.2 µg/mL. Furthermore, EPSNC2 showed a reducing power activity as well as a metal chelating activity in a dose dependant manner and the activity reached 98.5% at 1000 µg/ml. EPSNC2 had a significant and specific anticancer effect on CaCo-2 cell line without any effect on other cell lines and the IC50 was estimated to be 295.1 µg/mL. Our results regarding the antiviral activity against HSV-1, HAV and Coxsackie B-4 were 84.9%, 20.3 % and 45.4 %, respectively at 125 µg/mL with no activity against adenovirus. Therefore, the EC50 value against the enveloped virus HSV-1 was 32.4 µg/mL.
Key words: exopolysaccharide, Production, Streptomyces hirsutus, antioxidant, Anticancer, Antiviral
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