title: Improvement of steroid biotransformation with hydroxypropyl-beta-cyclodextrin induced complexation.
abstract: The inclusion complexes induced by cyclodextrins and its derivates have been shown previously to enhance the biotransformation of hydrophobic compounds. Using hydroxypropyl-beta-cyclodextrin (HP-beta-CD; 20% w/v), the water solubility of cortisone acetate increased from 0.039 to 7.382 g L(-1) at 32 degrees C. The solubilization effect of HP-beta-CD was far superior to dimethylformamide (DMF) and ethanol. The dissolution rate also significantly increased in the presence of HP-beta-CD. The enzymatic stability of Delta(1)-dehydrogenase from Arthrobacter simplex TCCC 11037 was not influenced by the increasing concentrations of HP-beta-CD contrary to the organic cosolvents which negatively influenced in the order DMF > ethanol. The activity inhibition effect caused by HP-beta-CD was not so conspicuous as ethanol and DMF. Inactivation constants of ethanol, DMF, and HP-beta-CD were 5.832, 4.541, and 1.216, respectively. The inactivation energy (E (a)) was in the order of HP-beta-CD (55.1 kJ mol(-1)) > ethanol (39.9 kJ mol(-1)) > DMF (37.1 kJ mol(-1)).
authors.affiliation: Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, People's Republic of China.
authors.forename: Liting
authors.initials: L
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Shen
authors.forename: Yinhu
authors.initials: Y
authors.lastname: Ma
authors.forename: Jianmei
authors.initials: J
authors.lastname: Luo
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D001173:Arthrobacter / Q000201:enzymology / Q000378:metabolism*; D004126:Dimethylformamide / Q000494:pharmacology; D004795:Enzyme Stability / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology; D010088:Oxidoreductases / Q000378:metabolism; D013256:Steroids / Q000737:chemistry* / Q000378:metabolism*; D047392:beta-Cyclodextrins / Q000494:pharmacology*
chemical_list: D013256:Steroids; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D000431:Ethanol; D004126:Dimethylformamide; D010088:Oxidoreductases; C022656:3-oxosteroid delta(1) dehydrogenase