Contents lists available at ScienceDirect Carbohydrate Polymers journal homepage: www.elsevier.com/locate/carbpol Structural studies of a water insoluble β-glucan from Pleurotus djamor and its cytotoxic effect against PA1, ovarian carcinoma cells Gajendra Nath Maity a , Prasenjit Maity b,e,f , Indranil Choudhuri c , Nandan Bhattacharyya c , Krishnendu Acharya d , Sudipta Dalai e , Soumitra Mondal b, ⁎ a Department of Microbiology, Panskura Banamali College, Panskura, Purba Midnapore, 721152, West Bengal, India b Department of Chemistry, Panskura Banamali College, Panskura, Purba Midnapore, 721152, West Bengal, India c Department of Biotechnology, Panskura Banamali College, Panskura, Purba Medinipur, 721152, West Bengal, India d Molecular and Applied Mycology and Plant Pathology Laboratory, Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, West Bengal, India e Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore, 721102, West Bengal, India f Department of Chemistry, Pingla Thana Mahavidyalaya, Maligram, 721140, Paschim Medinipur, West Bengal, India ARTICLE INFO Keywords: Edible mushroom β-glucan NMR experiments Cytotoxic effect Wound healing assay ABSTRACT A water insoluble β-glucan (PS), with molecular mass ∼9.16 × 10 4 Da was isolated from the 4% alkaline extract of an edible mushroom, Pleurotus djamor and found to consist of (1→3)-β-D-glucopyranosyl moiety. The structure of the PS was elucidated on the basis of total hydrolysis, methylation analysis, periodate oxidation, and NMR experiments ( 1 H, 13 C, DQF-COSY, DEPT-135, and HSQC). The structure of the repeating unit of the poly- saccharide was established as: →3)-β-D-Glcp-(1→. The water insoluble β-glucan showed cytotoxic effect against PA1 cells, where˜50% population was destroyed at 100 μg/mL concentration, and almost all cells at 250 μg/mL concentration. The wound healing assay showed significant anticarcinogenic effect against ovarian carcinoma PA1 cells after 48 h of treatment. 1. Introduction Edible mushrooms provide a significant source of nutritional as well as medicinal compounds and used for the development of drugs (Breene, 1990; Moradali, Mostafavi, Ghods, & Hedjaroude, 2007; Wang et al., 2014). Mainly, edible mushrooms are consumed by the people as delicious food ingredient and measured as a source of biomolecules such as proteins, fats, carbohydrates, amino acids, vitamins, minerals but the energy value of the mushroom varies for different species (Bello & Akinyele, 2007). Edible mushrooms are recognized as not only functional foods but also their bioactive compounds that have various valuable impacts on human health (Khan et al., 2016; Ren, Perera, & Hemar, 2012). Among the different bioactive polysaccharides, β-glucan is the most important as functional compounds in mushrooms (De Silva et al., 2013). Generally, β-glucans are a long chain polymers of glucose units linked by α- (alpha) and β- (beta) type glycosidic bonds present in the cell wall of oat, barley, yeast and mushrooms (Brown & Gordon, 2003; Chan, Chan, & Sze, 2009). It was found that β-glucans from different sources have different linkage types, branching manners and molecular weights (Du, Bian, & Xu, 2014). The structural diversity of mushroom β-glucans are linked by only β-(1→3) and linear β-(1→3), (1→6) linkages (Misaki & Kakuta, 1995; Ojha, Chandra, Ghosh, & Islam, 2010; Synytsya et al., 2009) and nonlinear form with β-(1→3) back bone branched at O-6 (Mizuno et al., 1990, Rout, Mondal, Chakraborty, & Islam, 2008), and β-(1→6) backbone branched at O-3 (Maji et al., 2012; Sen et al., 2013). However, the β-D-glucans are biologically important polysaccharide for enhancing and stimulating the immune systems of human body (Blascheck, Kasbauer, Kraus, & Franz, 1992; Chan et al., 2009; Kidd, 2000; Kiho, Sakushima, Wang, Nagai, & Ukai, 1991; Kulicke, Lettau, & Thielking, 1997; Smiderle et al., 2008). They have antitumor (Wasser, 2002) as well as antioxidant activities (Blokhina, Virolainen, & Fagerstedt, 2003; Kofuji et al., 2012; Papas, 1998). Several mushroom polysaccharides such as Lentinan (from Lentinus edodes, Japan), Schi- zophyllan (from Schizophyllum commune), Krestin (from turkey tail mushroom Trametes versicolor), Agarican (from Agaricus blazei, USA), and Grifron-D (from Grifola frondosa, Japan) have been established as pharmaceutical agents and anticancer drugs (Chihara, Maeda, Hamuro, https://doi.org/10.1016/j.carbpol.2019.114990 Received 22 April 2019; Received in revised form 22 May 2019; Accepted 10 June 2019 ⁎ Corresponding author. E-mail address: mondalsoumitra78@yahoo.com (S. Mondal). Carbohydrate Polymers 222 (2019) 114990 Available online 20 June 2019 0144-8617/ © 2019 Elsevier Ltd. All rights reserved. T