Structure elucidation and spectroscopic analysis of photodegradants of the anti-rhinitis drug fluticasone furoate.
Fluticasone furoate is a novel glucocorticoid receptor agonist marketed as a treatment for seasonal and perennial allergic rhinitis. Forced degradation of fluticasone furoate under conditions of light led to a number of degradation products, the structures of which were elucidated using mass spectrometry and a range of one and two-dimensional NMR experiments. Three structures were derived, including two which involved a rearrangement of the steroid ring A to give cross-linked degradation products. The results demonstrate the applicability of a previously observed mechanism of photodegradation to fluticasone furoate.
19β,28-Epoxy-18α-olean-3β-ol-2-furoate from Allobetulin (19β,28-Epoxy-18α-olean-3β-ol)
The E ring of betulin rearranges and forms a cyclic ether when treated with an acid. Treatment of betulin with iodine generated hydrogen iodide in situ, which went on to promote the rearrangement at C-19 and C-20, followed by cyclization to form allobetulin. A reaction of allobetulin with 2-furoyl chloride yielded 19β,28-Epoxy-18α-olean-3β-ol-2-furoate.
Photochemische Reaktionen 4. Mitteilung. Beeinflussung der photochemischen Isomerisierung gekreuzter Dienone durch Substituenten am Chromophor
Irradiation of 1-dehydro-4-methyl-testosterone (IV) in dioxane solution affords as a single product an isomer, which on the basis of extensive degradation is shown to possess structure V. A similar photochemical transformation leads from 1-dehydro-2,4-dimethyl-testosterone (XXXVII) to the corresponding lumiproduct XXXVIII. Since it has been previously shown that 1-dehydro-testosterone (III) under the same conditions yields a mixture of 8 compounds, it appears now that the photochemical isomerisation of cross-conjugated steroidal dienones is profoundly affected by the presence of a methyl substituent at C-4.