title: Biotransformations of ent-18-acetoxy-6-ketomanoyl oxides epimers at C-13 with filamentous fungi.
abstract: Two ent-18-acetoxy-6-oxomanoyl oxides, epimers at C-13, have been prepared from ent-6alpha,8alpha,18-trihydroxylabda-13(16),14-diene (andalusol), isolated from Sideritis foetens, by means of several chemical pathways and a regioselective acylation with Candida cylindracea lipase (CCL). Biotransformation of these 13-epimeric ent-manoyl oxides by Fusarium moniliforme and Neurospora crassa produced mainly ent-1beta- or ent-11alpha-hydroxylations, as well as their deacetylated derivatives, in both epimers. In addition, with the 13-epi substrate N. crassa originated other minor hydroxylations by the ent-alpha face at C-1 or at C-12, whereas an ent-11beta-hydroxyl group, probably originated by reduction of an 11-oxo derivative also isolated, was achieved with the 13-normal substrate.
authors.affiliation: Faculté des Sciences, Universite Abdelmalek Essaadi, Tetouan, Morocco.
authors.forename: Hanae
authors.initials: H
authors.lastname: Ghoumari
authors.forename: Mohamed-Hassan
authors.initials: MH
authors.lastname: Benajiba
authors.forename: Andrés
authors.initials: A
authors.lastname: García-Granados
authors.forename: Antonia
authors.initials: A
authors.lastname: Fernández
authors.forename: Antonio
authors.initials: A
authors.lastname: Martínez
authors.forename: Francisco
authors.initials: F
authors.lastname: Rivas
authors.forename: José M
authors.initials: JM
authors.lastname: Arias
mesh_terms: D001711:Biotransformation; D002244:Carbon / Q000737:chemistry / Q000378:metabolism*; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D005670:Fusarium / Q000378:metabolism*; D006900:Hydroxylation; D009492:Neurospora crassa / Q000378:metabolism*; D010087:Oxides / Q000378:metabolism*; D031365:Sideritis / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D004224:Diterpenes; D010087:Oxides; C110596:ent-13(16),14-labdadiene-6,8,18-triol; D002244:Carbon