title: [Microbial transformation of glycyrrhetinic acid by Cunninghamella blakesleeana].
abstract: A study on the microbial transformation of glycyrrhetinic acid (GA) was conducted by a fungus, Cunninghamella blakesleeana CGMCC 3.970 systematically. After incubation with the cell cultures of C. blakesleeana CGMCC 3.970 at 25 degrees C for 7 days on a rotary shaker operating at 135 r x min(-1), GA was converted into one major product and five minor products. The products were extracted and purified by solvent extraction, macroporous adsorbent resin, silica gel column chromatography, and semi-preparative RP-HPLC chromatography. Their structures were identified as 3-oxo-15α-hydroxy-18β-glycyrrhetinic acid(1), 3-oxo-15β-hydroxy-18β-glycyrrhetinic acid (2), 7β,15α-dihydroxy-18β-glycyrrhetinic acid (3), 3-oxo-7β, 15α-dihydroxy-18β-glycyrrhetinic acid (4), 7β-hydroxy-18β-glycyrrhetinic acid(5) and 15α-hydroxy-18β-glycyrrhetinic acid(6) by the analyses of MS, 1H-NMR and 13C-NMR spectroscopic data respectively. Among them, 2 was a new compound. These results suggest that C. blakesleeana CGMCC 3.970 has the capability of selective ketonization and hydroxylation for GA. [Key words] glycyrrhetinic acid; Cunninghamella blakesleeana CGMCC 3. 970; microbial transformation
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ma
authors.forename: Dan
authors.initials: D
authors.lastname: Xie
authors.forename: Zhao-hua
authors.initials: ZH
authors.lastname: Wang
authors.forename: Jun-gui
authors.initials: JG
authors.lastname: Dai
authors.forename: Xi-qiang
authors.initials: XQ
authors.lastname: An
authors.forename: Zheng-yi
authors.initials: ZY
authors.lastname: Gu
mesh_terms: D001711:Biotransformation; D020093:Cunninghamella / Q000378:metabolism*; D006034:Glycyrrhetinic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: C119129:18alpha-glycyrrhetinic acid; D006034:Glycyrrhetinic Acid