title: Leucopaxillus giganteus mycelium: effect of nitrogen source on organic acids and alkaloids.
abstract: The aim of this work was to find the most useful inorganic nitrogen source to enable Leucopaxillus giganteus to become a more nutritious mushroom, regarding organic acid and phenolic composition and total alkaloids content. For these, the influence of NH 4NO 3,NaNO 2, KNO 3,, and (NH 4) 2HPO 4 on the organic acid production was determined by HPLC-UV and total alkaloid content was assessed by a spectrophotometric method, after precipitation by Dragendorff's reagent. The results showed that L. giganteus presented an organic acid profile composed of oxalic, cis-aconitic, citric, and fumaric acids, citric acid being the major one. The quantitative organic acid profile and total alkaloid content were affected by the nitrogen source and depended on the developmental stage of mycelium and nitrogen availability. Despite being present in all samples, no phenolic compound could be identified.
authors.affiliation: REQUI MTE/ Serviço de Farmacognosia, Faculdade de Farmácia, Universidade do Porto, R. Aníbal Cunha 164, 4050-047 Porto, Portugal.
authors.forename: Bárbara
authors.initials: B
authors.lastname: Ribeiro
authors.forename: Paula B
authors.initials: PB
authors.lastname: Andrade
authors.forename: Paula
authors.initials: P
authors.lastname: Baptista
authors.forename: Lillian
authors.initials: L
authors.lastname: Barros
authors.forename: Isabel C F R
authors.initials: IC
authors.lastname: Ferreira
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Seabra
authors.forename: Patrícia
authors.initials: P
authors.lastname: Valentão
mesh_terms: D000363:Agaricales / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D000470:Alkaloids / Q000032:analysis*; D002264:Carboxylic Acids / Q000032:analysis*; D019343:Citric Acid / Q000032:analysis; D025282:Mycelium / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D017672:Nitrogen Compounds / Q000378:metabolism*; D010636:Phenols / Q000032:analysis; D010710:Phosphates / Q000378:metabolism; D012977:Sodium Nitrite / Q000378:metabolism
chemical_list: D000470:Alkaloids; D002264:Carboxylic Acids; D017672:Nitrogen Compounds; D010636:Phenols; D010710:Phosphates; C024788:ammonium phosphate; D019343:Citric Acid; D012977:Sodium Nitrite