title: Stereo- and regioselective hydroxylation of grindelic acid derivatives by Aspergillus niger.
abstract: Stereo- and regioselective hydroxylation of grindelane derivatives on position 3beta was catalyzed by cultures of Aspergillus niger. Grindelic acid (1), methyl grindelate (2), 15-hydroxy-7(8)-en-9alpha,13(S)-oxide-ent-labdane (3) and 7alpha,8alpha-epoxymethylgrindelate (4) were bioconverted into the corresponding 3beta-hydroxy derivatives as the only biotransformation products. 13(S),15-dihydroxy-8(9)-en-ent-labdane (5) remained unreacted under the same conditions. The conformational and electronic studies of the substrates are discussed.
authors: Intequi-Conicet. Area de Química Orgánica, Facultad de Química, Bioquímica y Farmacia, UNSL, Chacabuco y Pedernera, 5700, San Luis.
authors: A A
authors: AA
authors: Orden
authors: D A
authors: DA
authors: Cifuente
authors: E J
authors: EJ
authors: Borkowski
authors: C E
authors: CE
authors: Tonn
authors: M Kurina
authors: MK
authors: Sanz
mesh_terms: D001234:Aspergillus niger / Q000737:chemistry*; D001711:Biotransformation; D004224:Diterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D006900:Hydroxylation; D013237:Stereoisomerism
chemical_list: D004224:Diterpenes