title: Phytotoxic naphthopyranone derivatives from the coprophilous fungus Guanomyces polythrix.
abstract: Reinvestigation of the fermentation broth and mycelium of the coprophilous fungus Guanomyces polythrix, grown in static conditions, led to the isolation of several phytotoxic compounds, including two new naphthopyranone derivatives, namely (2S, 3R)-5-hydroxy-6,8-dimethoxy-2,3-dimethyl-2,3-dihydro-4H-naphtho[2,3-b]-pyran-4-one and (2S, 3R)-5-hydroxy-6,8,10-trimethoxy-2,3-dimethyl-2,3-dihydro-4H-naphtho[2,3-b]-pyran-4-one. The structures of the new compounds were established by spectral and chiroptical methods. In addition, the structure of 8-hydroxy-6-methyl-9-oxo-9H-xanthene-1-carboxylic acid methyl ester was unambiguously determined by X-ray analysis. The isolates caused significant inhibition of radicle growth of two weed seedlings (Amaranthus hypochondriacus and Echinochloa crusgalli) and interacted with both spinach and bovine brain calmodulins.
authors.affiliation: Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, D.F. 04510, Mexico.
authors.forename: M
authors.initials: M
authors.lastname: Macías
authors.forename: A
authors.initials: A
authors.lastname: Gamboa
authors.forename: M
authors.initials: M
authors.lastname: Ulloa
authors.forename: R A
authors.initials: RA
authors.lastname: Toscano
authors.forename: R
authors.initials: R
authors.lastname: Mata
mesh_terms: D027721:Amaranthus / Q000187:drug effects* / Q000254:growth & development; D002147:Calmodulin / Q000378:metabolism; D018360:Crystallography, X-Ray; D005285:Fermentation / Q000502:physiology; D005658:Fungi / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008968:Molecular Conformation; D009281:Naphthalenes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*; D011485:Protein Binding; D011753:Pyrones / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: C448079:(2,3)-5-hydroxy-6,8-dimethoxy-2,3-dimethyl-2,3-dihydro-4H-naphtho(2,3-b)-pyran-4-one; D002147:Calmodulin; D006540:Herbicides; D009281:Naphthalenes; D011753:Pyrones