668-56-4Relevant academic research and scientific papers
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).
Testosterone prodrugs for improved drug delivery
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, (2008/06/13)
Compositions and methods are provided for enhanced transdermal electrotransport of 17-hydroxy sterol compounds, including testosterone. The parent sterols are modified at the 17-hydroxy position by covalent attachment of a charged chemical modifier. The chemical modifier provides the parent sterol with enhanced transport properties and is hydrolyzed under physiological conditions to release the active parent compound. The composition comprises a 17-hydroxy sterol/chemical modifier complex, more generally represented by the formula (sterol--O--)C(O)--R--N(R1)(R2)(R3)+. The portion of the complex derived from the chemical modifier is indicated by "C(O)--R--N(R1)(R2)(R3)+ ", where N(R1)(R2)(R3)+ represents a quaternary ammonium group and R1, R2, and R3 are independently selected from the group consisting of lower alkyl, alkyl, aryl, arylalkyl, cycloalkyl, heteroalkyl, and heteroarylalkyl; or R1 and R2 together with the nitrogen to which they are attached form a substituted heterocycle and R3 is lower alkyl, and R is a linking moiety, linking the (sterol--O)--C(O)-- to the nitrogen atom.
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.
Testicular-specific drug delivery
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, (2008/06/13)
Testicularly acting drug species are site-specifically/sustainedly delivered to the testes by administering to a male in need of such treatment a pharmacologically effective amount of the target drug species [D] tethered to a reduced, blood-testis barrier penetrating lipoidal form [D--DHC] of a dihydropyridine pyridinium salt type redox carrier, e.g. 1,4-dihydrotrigonelline. Oxidation of the dihydropyridine carrier moiety in vivo to the ionic pyridinium salt type drug/carrier entity [D--QC]+ prevents elimination thereof from the testes, while elimination from the general circulation is accelerated, resulting in significant and prolongedly sustained testicular-specific drug activity, whether ascribable to the cleavage of the [D--QC]+ entity and sustained release of the drug [D] in the testes and/or to [D--QC]+ itself.
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 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.
Brain-specific drug delivery
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, (2008/06/13)
Centrally acting drug species are site-specifically/sustainedly delivered to the brain by administering to a patient in need of such treatment a therapeutically effective amount of the target drug species [D] tethered to a reduced, blood-brain barrier penetrating lipoidal form [D-DHC] of a dihydropyridine pyridinium salt type redox carrier. Oxidation of the dihydropyridine carrier moiety in vivo to the ionic pyridinium salt type drug/carrier entity [D-QC]+ prevents elimination thereof from the brain, while elimination from the general circulation is accelerated, and subsequent cleavage of the quaternary carrier/drug species results in sustained delivery of the drug [D] in the brain and facile elimination of the carrier moiety [QC]+.
Improved delivery through biological membranes XIV: Brain-specific, sustained delivery of testosterone using a redox chemical delivery system
Bodor,Farag
, p. 385 - 389 (2007/10/02)
The dihydropyridine ? pyridinium salt redox delvery system was used for the specific delivery and sustained release of testosterone in the brain. Administration of the N-methyl-1,4-dihydro nicotinate ester of testosterone in female rats gave high and sustained brain levels of the corresponding quaternary ester, testosterone trigonellinate. This contrasted with rapid elimination from the general circulation. Release of testosterone 'locked into' brain as the quaternary salt was sustained, t 1/2 =20 h.
