668-56-4Relevant articles and documents
Synthesis of pyridine-carboxylate derivatives of hydroxysteroids for liquid chromatography-electrospray ionization-mass spectrometry
Yamashita, Kouwa,Kobayashi, Sayuri,Tsukamoto, Satoshi,Numazawa, Mitsuteru
, p. 50 - 59 (2007/10/03)
Synthesis and liquid chromatography-electrospray ionization-mass spectrometric (LC-ESI-MS) behaviors of the picolinoyl, 6-methylpicolinoyl, nicotinoyl, 2-methoxynicotinoyl and isonicotinoyl derivatives of the hydroxysteroids estrone, estradiol, 3β-hydroxyandrost-5-en-17-one (dehydroepiandrosterone) and testosterone in positive mode were investigated. Each steroid was converted to the corresponding pyridine-carboxylate derivative by the acyl chloride method or the mixed anhydride method using the corresponding free acids and 2-methyl-6-nitrobenzoic anhydride; in each case, the latter method principally gave a better yield. The pyridine-carboxylate derivative of each steroid exhibited a clear single peak in liquid chromatography with a reversed phase column and CH3CN-0.1% CH3COOH as a mobile phase. The positive-ESI-mass spectra of the picolinoyl, 6-methylpicolinoyl and 2-methoxynicotinoyl derivatives showed a predominance of [M+H]+, whereas [M+H+CH3CN]+ was observed with high intensity in the nicotinoyl and isonicotinoyl derivatives. Even in the case of estradiol, with its two hydroxyl groups, a single charged ion of [M+H]+ or [M+H+CH3CN]+ was observed in the positive-ESI-mass spectrum of each derivative. The results revealed that picolinoyl derivatization is a simple and versatile method suitable for the sensitive and specific determination of hydroxysteroids by LC-ESI-MS (selected reaction monitoring).
Brain-specific drug delivery
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, (2008/06/13)
The subject compounds, which are adapted for the site-specific/sustained delivery of centrally acting drug species to the brain, are: (a) compounds of the formula wherein [D] is a centrally acting drug species, and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine pyridinium salt redox carrier, with the proviso that when [DHC] is STR1 wherein R is lower alkyl or benzyl and [D] is a drug species containing a single NH2 or OH functional group, the single OH group when present being a primary or secondary OH group, said drug species being linked directly through said NH2 or OH function group to the carbonyl function of [DHC], then [D] must be other than a sympathetic stimulant, steroid sex hormone or long chain alkanol; and (b) non-toxic pharmaceutically acceptable salts of compounds of formula (I) wherein [D] is a centrally acting drug species and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine pyridinium salt redox carrier. The corresponding ionic pyridinium salt type drug/carrier entitles [D--QC]+ X- are also disclosed.
Brain-specific drug delivery
-
, (2008/06/13)
The subject compounds, which are adapted for the site-specific/sustained delivery of centrally acting drug species to the brain, are: (a) compounds of the formula wherein [D] is a centrally acting drug species, and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine pyridinium salt redox carrier, with the proviso that when [DHC] is STR1 wherein R is lower alkyl or benzyl and [D] is a drug species containing a single NH2 or OH functional group, the single OH group when present being a primary or secondary OH group, said drug species being linked directly through said NH2 or OH functional group to the carbonyl function of [DHC], then [D] must be other than a sympathetic stimulant, steroid sex hormone or long chain alkanol; and (b) non-toxic pharmaceutically acceptable salts of compounds of formula (I) wherein [D] is a centrally acting drug species and [DHC] is the reduced, biooxidizable, blood-brain barrier penetrating lipoidal form of a dihydropyridine pyridinium salt redox carrier. The corresponding ionic pyridinium salt type drug/carrier entities [D-QC]+ Y- are also disclosed.
