International Journal of Biological Macromolecules 70 (2014) 354–359 Contents lists available at ScienceDirect International Journal of Biological Macromolecules j ourna l ho me pa g e: www.elsevier.com/locate/ijbiomac Water-soluble polysaccharides from Pleurotus ostreatus var. florida mycelial biomass Dirce L. Komura a , Andrea C. Ruthes b , Elaine R. Carbonero c , Philip A.J. Gorin b , Marcello Iacomini b,∗ a Instituto Nacional de Pesquisas da Amazônia (INPA), Av. André Araújo, 2936, CEP 69060-001 Manaus, AM, Brazil b Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba CEP 81531-980, Brazil c Departamento de Química, Universidade Federal de Goiás, Campus Catalão, CEP 75704-020 Catalão, GO, Brazil a r t i c l e i n f o Article history: Received 12 March 2014 Received in revised form 19 May 2014 Accepted 5 June 2014 Available online 5 July 2014 Keywords: Pleurotus spp. Mycelia Mannogalactan Glucans a b s t r a c t Pleurotus ostreatus var. florida known as Hiratake has a high nutritional value, presents medicinal and nutraceutical properties and it is one of the consumed mushrooms in Brazil. Thus, the aim of this study was to characterize the chemical structure of polysaccharides found in mycelial biomass produced by submerged culture of P. ostreatus var. florida in order to compare with those found in P. ostreatus var. florida fruit bodies. Aqueous and alkali extracts obtained from mycelial biomass were purified, 13 C NMR, GC–MS and chemical techniques were used to characterize three polysaccharide structures: a mannogalactan (MG-PfM) with -d-Galp and 3-O-Me--d-Galp units, both (1 → 6)-linked, highly substituted at O-2 by D- Manp, a glycogen-like polymer (GLY-PfM) with -d-Glp (1 → 4)-linked main chain, partially substituted at O-6 by -d-Glcp side chains and a (1 → 3), (1 → 6) -d-glucan (GLC-PfM) with a main chain of -d-Glcp (1 → 3)-linked units, partially substituted at O-6 by side chains of 6-O-substituted -d-glucopyranosyl units, on an average of one to every two residues of the backbone. These results show the possibility to obtain similar and also different molecules from those found in the fruiting body of the same mushroom species, therefore the submerged culture of mushroom is a promising way to give raise molecules of interest. © 2014 Published by Elsevier B.V. 1. Introduction Mushrooms of the genus Pleurotus are widely distributed in many countries, and numerous native species of this genus occur in Brazil, although most of them are scarcely known. Pleuro- tus ostreatus is one of the most commercialized species in the world; other consumed species are P. ostreatus var. florida, Pleu- rotus ostreatoroseus and Pleurotus eryngii [1]. These mushrooms are good sources of carbohydrates with high quantities of dietary fibers, besides proteins with almost all of the essential amino acids, min- eral and vitamins [2], and also -d-glucans, which could be found in both, soluble and insoluble dietary fractions [3]. Abbreviations: 13 C NMR, nuclear magnetic resonance (NMR) spectroscopy to carbon; EPS, exopolysaccharide; EtOH, etanol; GC–MS, gas chromatography–mass spectrometry; HPSEC-MALLS, high-performance steric exclusion chromatography- coupled with multiangle laser light-scattering; TFA, Trifluoroacetic acid. ∗ Corresponding author. Tel.: +55 41 3361 1655; fax: +55 41 3266 2042. E-mail addresses: leimybio@gmail.com (D.L. Komura), andrearuthes@gmail.com (A.C. Ruthes), elainecarbonero@gmail.com (E.R. Carbonero), cesarat@ufpr.br (P.A.J. Gorin), iacomini@ufpr.br (M. Iacomini). Polysaccharides from Pleurotus sp. have been studied mainly in search of molecules that could act as biological response modifiers, such as antitumor from Pleurotus citrinopileatus [4], antihyperglycemic from fermented broth of P. citrinopileatus [5], anti-proliferative and pro-apoptotic activities of fractions from P. ostreatus on HT-29 colon cancer cells [6] and anti-inflammatory and analgesic properties from fruiting body of Pleurotus pulmonarius [7]. Mushrooms produce many types of polysaccharide structures, glucans are the most described, but heterogalactans can also be found, and in addition to fruiting body, polysaccharides could also be isolated from culture medium, as exopolysaccharides (EPS), and mycelia, both from submerged culture. The cultivation of mush- rooms requires a long time to produce fruiting bodies whereas the submerged culture only requires a short time to mass-produce mycelia [8]. Many reports concerning to the mushroom polysaccharides are mainly focused on EPS production and evaluation of fruiting bodies polysaccharides. Moreover, studies related to mycelial polysaccha- rides keeps away from the main focus of most researchers, and have been scarcely reported [4,9,10], when compared to EPS. http://dx.doi.org/10.1016/j.ijbiomac.2014.06.007 0141-8130/© 2014 Published by Elsevier B.V.