title: Purification, Chemical Characterization, and Bioactivity of an Extracellular Polysaccharide Produced by the Marine Sponge Endogenous Fungus Alternaria sp. SP-32.
abstract: Marine sponges are ancient and simple multicellular filter-feeding invertebrates attached to solid substrates in benthic habitats and host a variety of fungi both inside and on their surface because of its unique ingestion and digest system. Investigation on marine sponge-associated fungi mainly focused on the small molecular metabolites, yet little attention had been paid to the extracellular polysaccharides. In this study, a homogeneous extracellular polysaccharide AS2-1 was obtained from the fermented broth of the marine sponge endogenous fungus Alternaria sp. SP-32 using ethanol precipitation, anion-exchange, and size-exclusion chromatography. Results of chemical and spectroscopic analyses showed that AS2-1 was composed of mannose, glucose, and galactose with a molar ratio of 1.00:0.67:0.35, and its molecular weight was 27.4 kDa. AS2-1 consists of a mannan core and a galactoglucan chain. The mannan core is composed of (1→6)-α-Manp substituted at C-2 by (1→2)-α-Manp with different degrees of polymerization. The galactoglucan chain consists of (1→6)-α-Glcp residues with (1→6)-β-Galf residues attached to the last glucopyranose residue at C-6. (1→6)-β-Galf residues have additional branches at C-2 consisting of disaccharide units of (1→2)-β-Galf and (1→2)-α-Glcp residues. The glucopyranose residue of the galactoglucan chain is linked to the mannan core. AS2-1 possessed a high antioxidant activity as evaluated by scavenging of 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals in vitro. AS2-1 was also evaluated for cytotoxic activity on Hela, HL-60, and K562 cell lines by the MTT and SRB methods. The investigation demonstrated that AS2-1 was a novel extracellular polysaccharide with different characterization from extracellular polysaccharides produced by other marine microorganisms.
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drugs and Foods, Ocean University of China, 5 Yushan Road, Qingdao, 266003, People's Republic of China.|College of Food and Pharmacy, Zhejiang Ocean University, 18 Haiyuan Road, Zhoushan, 316000, People's Republic of China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drugs and Foods, Ocean University of China, 5 Yushan Road, Qingdao, 266003, People's Republic of China. wenjunmqd@hotmail.com.
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Mao
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drugs and Foods, Ocean University of China, 5 Yushan Road, Qingdao, 266003, People's Republic of China.
authors.forename: Meng-Xia
authors.initials: MX
authors.lastname: Yan
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drugs and Foods, Ocean University of China, 5 Yushan Road, Qingdao, 266003, People's Republic of China.
authors.forename: Xue
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drugs and Foods, Ocean University of China, 5 Yushan Road, Qingdao, 266003, People's Republic of China.
authors.forename: Shu-Yao
authors.initials: SY
authors.lastname: Wang
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drugs and Foods, Ocean University of China, 5 Yushan Road, Qingdao, 266003, People's Republic of China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Xia
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drugs and Foods, Ocean University of China, 5 Yushan Road, Qingdao, 266003, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drugs and Foods, Ocean University of China, 5 Yushan Road, Qingdao, 266003, People's Republic of China.
authors.forename: Su-Jian
authors.initials: SJ
authors.lastname: Cao
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drugs and Foods, Ocean University of China, 5 Yushan Road, Qingdao, 266003, People's Republic of China.
authors.forename: Bao-Qin
authors.initials: BQ
authors.lastname: Yang
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Institute of Marine Drugs and Foods, Ocean University of China, 5 Yushan Road, Qingdao, 266003, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
mesh_terms: D000528:Alternaria / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000037:antagonists & inhibitors; D002240:Carbohydrate Sequence; D002470:Cell Survival / Q000187:drug effects; D005285:Fermentation; D062610:Fungal Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D005685:Galactans / Q000737:chemistry; D005690:Galactose / Q000737:chemistry; D005936:Glucans / Q000737:chemistry; D005947:Glucose / Q000737:chemistry; D018922:HL-60 Cells; D006367:HeLa Cells; D006801:Humans; D017665:Hydroxyl Radical / Q000037:antagonists & inhibitors; D020014:K562 Cells; D008351:Mannans / Q000737:chemistry; D008358:Mannose / Q000737:chemistry; D008970:Molecular Weight; D010851:Picrates / Q000037:antagonists & inhibitors; D011135:Polysaccharides, Bacterial / Q000737:chemistry; D011161:Porifera / Q000382:microbiology*; D012623:Seawater / Q000382:microbiology; D052616:Solid Phase Extraction / Q000379:methods; D013559:Symbiosis / Q000502:physiology
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D062610:Fungal Polysaccharides; D005685:Galactans; D005936:Glucans; D008351:Mannans; D010851:Picrates; D011135:Polysaccharides, Bacterial; D017665:Hydroxyl Radical; C093768:galactoglucan; C004931:1,1-diphenyl-2-picrylhydrazyl; D005947:Glucose; D008358:Mannose; D005690:Galactose
keywords: Alternaria sp. SP-32; Bioactivity; Chemical characterization; Extracellular polysaccharide; Marine sponge endogenous fungus