title: Biotransformation of oleanolic and maslinic methyl esters by Rhizomucor miehei CECT 2749.
abstract: The pentacyclic triterpenoids methyl oleanolate, methyl maslinate, methyl 3β-hydroxyolean-9(11),12-dien-28-oate, and methyl 2α,3β-dihydroxy-12β,13β-epoxyolean-28-oate were biotransformed by Rhizomucor miehei CECT 2749. Microbial transformation of methyl oleanolate produced only a 7β,30-dihydroxylated metabolite with a conjugated 9(11),12-diene system in the C ring. Biotransformation of the substrate with this 9(11),12-diene system gave the same 7β,30-dihydroxylated compound together with a 7β,15α,30-trihydroxyl derivative. The action of this fungus (R. miehei) on methyl maslinate was more varied, isolating metabolites with a 30-hydroxyl group, a 9(11),12-diene system, an 11-oxo group, or an 12-oxo group. Microbial transformation of the substrate with a 12β,13β-epoxy function resulted in the isolation of two metabolites with 12-oxo and 28,13β-olide groups, hydroxylated or not at C-7β, together with a 30-hydroxy-12-oxo derivative. The structures of these derivatives were deduced by extensive and rigorous spectroscopic studies.
authors.affiliation: Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain. Electronic address: aramon@ugr.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Martinez
authors.affiliation: Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Perojil
authors.affiliation: Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain. Electronic address: frivas@ugr.es.
authors.forename: Francisco
authors.initials: F
authors.lastname: Rivas
authors.affiliation: Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain.
authors.forename: Andres
authors.initials: A
authors.lastname: Parra
authors.affiliation: Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain.
authors.forename: Andres
authors.initials: A
authors.lastname: Garcia-Granados
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain.
authors.forename: Antonia
authors.initials: A
authors.lastname: Fernandez-Vivas
mesh_terms: D006900:Hydroxylation; D015394:Molecular Structure; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D020103:Rhizomucor / Q000378:metabolism*
chemical_list: C077960:methyl maslinate; D009828:Oleanolic Acid
keywords: Biohydroxylation; Biotransformation; Maslinic acid; Methyl maslinate; Methyl oleanolate; Oleanolic acid; Rhizomucor miehei; Triterpenoids