- Photodegradation products of methylprednisolone suleptanate in aqueous solution - Evidence of a bicyclo[3.1.0]hex-3-en-2-one intermediate
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Two major photodegradation products of methylprednisolone suleptanate (sodium 11β, 17α-dihydroxy-6α-methyl-21-[[8-[methyl(2-sulfoethyl)amino]- 1,8-dioxooctyl]oxy]-pregna-1,4-diene-3,20-dione) in aqueous solution irradiated with white fluorescent light at 2000 lux for 28 days at 25 °C were isolated by preparative high-performance liquid chromatography and characterized. Structures of the photodegradation products were determined as sodium 11β,17α-dihydroxy-5α,6α-dimethyl-21-[[8-[methyl(2- sulfoethyl)amino]-1,8-dioxooctyl]-oxy]-19-norpregna-1(10),3-diene-2,20-dione and sodium 1β,11β-epoxy-17α-hydroxy-6α-methyl-21-[[8-[methyl(2- sulfoethyl)amino]-1,8-dioxooctyl]oxy]-19α-pregn-4-ene-2,20-dione. Formation of these compounds, especially the 1,11-epoxy analogue, strongly supports the existence of the bicyclo[3.1.0]hex-3-en-2-one intermediate in the photorearrangement of steroidal cross-conjugated dienones. The intermediate can account for all the major ketonic and phenolic products; these products are generated from the intermediate after subsequent transformations and/or further skeletal rearrangements. The 1,11-epoxy analogues were obtained from the prednisolone steroids in high yields by irradiation with a high-pressure mercury lamp.
- Ogata, Minoru,Noro, Yukimi,Yamada, Mayumi,Tahara, Tsutomu,Nishimura, Toshihide
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- Radiolytic degradation scheme for 60Co-irradiated corticosteroids
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The cobalt 60 radiolytic degradation products have been identified in the following corticosteroids: cortisone, cortisone acetate, hydrocortisone, hydrocortisone acetate, hydrocortisone sodium succinate, isoflupredone acetate, methylprednisolone, methylprednisolone acetate, prednisolone, prednisolone acetate, and prednisone. Two major types of degradation processes have been identified: loss of the corticoid side chain the D-ring to produce the C-17 ketone and conversion of the C-11 alcohol, if present, to the C-11 ketone. Minor degradation products derived from other changes affecting the side chain are also identified in several corticosteroids. These compounds are frequently associated in corticosteroids as process impurities or degradation compounds. No new radiolytic compounds unique to 60Co-irradiation have been found. The majority of corticosteroids have been shown to be stable to 60Co-irradiation. The rates of radiolytic degradation ranged from 0.2 to 1.4%/Mrad.
- Kane,Tsuji
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