2D-NMR spectroscopy 2 6beta,7beta,15beta,16beta dimethylene 11alpha hydroxy 3 oxo 17alpha pregn 4 en 21,17 carbolactone 2 6beta,7beta,15beta,16beta dimethylene 11alpha hydroxy 3 oxo 17beta pregn 4 en 21,17 carbolactone 2 6beta,7beta,15beta,16beta dimethylene 11beta hydroxy 3 oxo 17alpha pregn 4 en 21,17 carbolactone 2 6beta,7beta,15beta,16beta dimethylene 2beta hydroxy 3 oxo 17alpha pregn 4 en 21,17 carbolactone 2 Absidia 2 Absidia corymbifera 2 Agitation speed 2 Biotransformation 2 Candida 2 Candida aphidicola 2 Drospirenone 2 Epimerization 2 Fungi 2 Hydroxylation 2 Microbial transformation 2 Mucor 2 Mucor plumbeus 2 Mucorales 2 Nuclear magnetic resonance spectroscopy 2 Rhizopus oryzae 2 Syncephalastrum racemosum 2 Zygomycetes 2 absidia coerulea 2 agitation 2 animal cell 2 article 2 cell growth 2 chemical structure 2 controlled study 2