In the present research, the steroidal antiinflammatory topically used drug prednicarbate (1) was subjected to microbial biotransformation by Cunninghamella elegans. Prednicarbate (1) was transformed into various metabolites. One new and two known metabolites were purified named as prednisolone 17-ethylcarbonate (2) Prednisolone (3) and 4-(4-hydroxybenzyl)-2-(3-methylbut-2-enyl)phenyl methyl carbonate (4). The compound (4) was separated as a new compound and was not reported in literature. Its structure did not show resemblance with prednicarbate so possibly derived from fungal mass. Their structures were elucidated by using modern spectroscopic techniques e.g. 13C NMR, 1H NMR, HMQC, HMQC, COSY, NOESY and mass spectrometry e.g. EI-MS.
The invention relates to compositions comprising a glucocorticoid-nitrooxyderivative and at least an active ingredient, to topical pharmaceutical formulations thereof. The invention also relates to the use for treating skin or mucosal membrane diseases or disorders. These compositions have an improved pharmacological activity and enhanced local tolerability.