title: Properties of aqueous solutions of lentinan in the absence and presence of zwitterionic surfactants.
abstract: Morphological and conformational transitions of lentinan (LT), a β-glucan extracted from Shiitake mushrooms (Lentinula edodes), were investigated at different concentrations of aqueous NaOH, using Small Angle X-ray Scattering (SAXS) technique. At low NaOH(aq) concentration LT chains are self-associated and adopt the triple helix form where as at higher NaOH concentrations the polymer chains undergo a transition to random coil chains. Also, the presence of fractal dimensions was observed through analysis of the exponential decay of the scattering intensity as a function of the scattering angle. In addition, the lateral radius of gyration was determined for LT in different concentrations of NaOH solution, indicating a rigid triple helix present as a small rod-like structure. Interactions of LT with two zwitterionic surfactants were investigated by surface tension, fluorescence, and static light scattering measurements. Experimental data showed that the formation of LT-(surfactant) complexes occurred through a cooperative process.
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, UFSC, Florianópolis, SC 88040-900, Brazil.
authors.forename: Leandro G
authors.initials: LG
authors.lastname: Nandi
authors.forename: João P T A
authors.initials: JP
authors.lastname: Guerra
authors.forename: Ismael C
authors.initials: IC
authors.lastname: Bellettini
authors.forename: Vanderlei G
authors.initials: VG
authors.lastname: Machado
authors.forename: Edson
authors.initials: E
authors.lastname: Minatti
mesh_terms: D007912:Lentinan / Q000737:chemistry*; D008027:Light; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012542:Scattering, Radiation; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000644:Quaternary Ammonium Compounds; D012996:Solutions; D013501:Surface-Active Agents; D014867:Water; C034730:zwittergent 3-12; C048256:zwittergent 3-14; D007912:Lentinan
keywords: Helix-coil transition; Lentinan; Polysaccharides; SAXS; Zwitterionic surfactants