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1.
Steroids ; 77(12): 1233-41, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22842234

RESUMO

During an initial study in searching for the alternative derivatives suitable for photolabeling of neuroactive steroids, perfluorobenzoates and perfluorobenzamides in position 17 of 5ß-androstan-3α-ol were synthesized from the corresponding 17-hydroxy and 17-amino derivatives. After transformation into glutamates or sulfates, 17α-epimers had comparable inhibitory activity at NMDA receptors to the natural neurosteroid (20-oxo-5ß-pregnan-3ß-yl sulfate), however, were more potent (2- to 36-fold) than their 17ß-substituted analogs. In one case, fluorine in position 4' of perfluorobenzoate group was substituted with azide and activity of the final glutamate was retained comparing with the corresponding perfluorobenzoate. The series was expanded with perfluorobenzoyl derivatives of pregnanolone: Perfluorobenzamide of glutamate and perfluorobenzoate of 11α-hydroxy pregnanolone were prepared and tested. From nine tested compounds, four of them exhibit very good inhibition activity and can serve as promising leads for photolabeling experiments.


Assuntos
Fluorocarbonos/química , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Esteroides/química , Esteroides/farmacologia , Azidas/química , Ácido Glutâmico/química , Células HEK293 , Humanos , Pregnanos/química , Pregnanolona/química , Esteroides/síntese química
2.
Steroids ; 76(10-11): 1043-50, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21545806

RESUMO

Analogs of pregnanolone (3α-hydroxy-5ß-pregnan-20-one), modified in position 17 were prepared. Compounds with 20-keto pregnane side chain replaced completely by azide (17α- and 17ß-azido-5ß-androstan-3α-ol), compounds with its part replaced (20-azido-21-nor-5ß-pregnan-3α-ol), and compounds with keto group only replaced ((20R)- and (20S)-20-azido-5ß-pregnan-3α-ol) were synthesized using tosylate displacements with sodium azide or Mitsunobu reaction with azoimide. All five azido steroids were converted into corresponding sulfates. Subsequent tests for inhibition of glutamate induced response on NMDA receptors revealed that modification of pregnanolone sulfate side chain with azide did not disturb the activity and some of sulfates tested were more active than parent compound.


Assuntos
Dioscoreaceae/química , Esteroides/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular
3.
Steroids ; 75(10): 721-5, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20470814

RESUMO

A series of keto steroids were reduced with sodium borohydride in the presence of cerium(III) chloride or samarium(III) iodide (Luche reduction). The ratios of axial and equatorial alcohols were determined by HPLC and the results were compared with those obtained by a standard sodium borohydride reduction. The best results were obtained with the 2-keto derivative 1, 7-keto derivatives 5 and 6, and 12-keto derivative 8 where the cerium(III) ion addition resulted in the inversion of the axial/equatorial ratios. The Luche reduction of the 20-keto derivative 11 improved the proportion of the (20S)-alcohol in a mixture of (20S)/(20R) alcohols up to 35% from 5% in a standard sodium borohydride reduction.


Assuntos
Boroidretos/química , Cetonas/química , Esteroides/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Oxirredução , Estereoisomerismo
4.
Steroids ; 74(1): 88-94, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18950651

RESUMO

New type of linear cholesterol-like molecules based on cholesterol extended by attachment of etienic acid derivatives was designed and oligosteroids with two to four units were synthesized. Amide bond was used for inter steroid connections and 1-hydroxybenzotriazole active ester method was adapted for their formations. Use of disteroids as larger building blocks was applied.


Assuntos
Amidas/química , Androstenos/química , Colesterol/química , Colesterol/síntese química , Estrutura Molecular
5.
Steroids ; 74(2): 256-63, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19071149

RESUMO

The synthesis of several novel 5alpha- and 5beta-20-oxo-pregnane derivatives substituted in the position 3 and 7 of the steroid skeleton is described. Activity of synthesized compounds was studied in voltage-clamped cultured rat hippocampal neurons. Substituted derivatives inhibited NMDA-elicited neuronal activity. The relationship between biological activity and structure is discussed.


Assuntos
Hipocampo/citologia , Neurônios/efeitos dos fármacos , Pregnanos/síntese química , Pregnanos/farmacologia , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Células Cultivadas , Condutividade Elétrica , Concentração Inibidora 50 , Neurônios/metabolismo , Técnicas de Patch-Clamp , Pregnanos/química , Ratos
6.
Bioorg Med Chem ; 16(7): 3704-13, 2008 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-18295492

RESUMO

Twelve steroidal platinum(II) complexes were synthesized by reaction of potassium tetrachloroplatinate with steroidal esters of L-methionine and L-histidine. The steroidal esters coordinated as bidentate ligands via S and N donor atoms of L-methionine and via two N donor atoms of L-histidine. Cholesterol, cholestanol, diosgenine, pregnenolone, dehydroepiandrosterone, testosterone, estrone, and estradiol were used as the steroidal compounds. The esters and complexes prepared were characterized by infrared, mass, and (1)H NMR spectroscopy and elemental analysis. Platinum complexes were tested for in vitro cytotoxicity against several cancer cell lines: T-lymphoblastic leukemia CEM, breast carcinoma MCF-7, lung carcinoma A-549, multiple myeloma RPMI 8226, and one normal cell line human fibroblast BJ.


Assuntos
Ésteres/síntese química , Ésteres/toxicidade , Platina/química , Esteroides/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ésteres/química , Histidina/química , Humanos , Espectroscopia de Ressonância Magnética , Metionina/química , Estrutura Molecular , Relação Estrutura-Atividade
7.
J Clin Endocrinol Metab ; 91(8): 3092-9, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16720657

RESUMO

BACKGROUND: Pregnanolone isomers (PI) with a hydroxy group in the 3alpha-position are neuroinhibitors operating via positive modulation of GABA(A) receptors. The 3beta-PI and sulfates of PI and pregnenolone exert the opposite effect. In addition to the brain's in situ synthesis, some circulating steroids can penetrate the blood-brain barrier. METHODS: To assess the physiological impact of peripheral endogenous neuroactive pregnanolone isomers and their polar conjugates in women, serum allopregnanolone (P3alpha5alpha), isopregnanolone (P3beta5alpha), pregnanolone (P3alpha5beta), epipregnanolone (P3beta5beta), pregnenolone, estradiol (including their polar conjugates), and additional steroids were measured in 16 women in the follicular and luteal phases of the menstrual cycle using gas chromatography/mass spectrometry and RIA for the analysis. Linear models and Spearman's correlations were used for data evaluation. RESULTS AND DISCUSSION: The levels of conjugated PI were from one to almost three orders of magnitude higher in comparison with the free steroids. The results indicate that a substantial proportion of the progesterone is metabolized in the sequence progesterone-->5beta-dihydroprogesterone-->P3alpha5beta-->conjugated P3alpha5beta. The sulfation of PI and particularly of P3alpha5beta moderates the levels of free PI and restrains estradiol biosynthesis via progesterone degradation. PI including the conjugates reflected changing progesterone formation during the menstrual cycle. In the follicular phase, the positive correlation with conjugated pregnenolone, the independence of progesterone, and the negative age relationships of PI indicate their adrenal origin. The dependence on progesterone and the independence of conjugated pregnenolone suggest a gonadal source of PI in the luteal phase. The neuroactivating PI prevailed over neuroinhibiting PI.


Assuntos
Pregnanolona/sangue , Adulto , Envelhecimento , Desidroepiandrosterona/sangue , Estradiol/sangue , Feminino , Fase Folicular , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Isomerismo , Fase Luteal , Pregnanolona/química , Pregnenolona/sangue , Progesterona/sangue , Receptores de GABA-A/efeitos dos fármacos
8.
Steroids ; 71(2): 120-8, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16242742

RESUMO

O-(Carboxymethyl)oximes 1 and 2 derived from two epimeric 5beta-pregnanolones (3beta-hydroxy-5beta-pregnan-20-one and 3alpha-hydroxy-5beta-pregnan-20-one) in position 19 were prepared. Two synthetic routes were employed, both using protection of the 20-keto group after reduction into the (20R)-alcohol in the form of acetate. In the first route, (20R)-19-hydroxy-5beta-pregnan-3beta,20-diyl diacetate (3) was transformed into the corresponding 19-[O-(carboxymethyl)oxime] methyl ester 6, then deacetylated by acid and partially silylated with tert-butyldimethylsilyl chloride. The desired 3-O-silylated derivative 8 was separated, oxidized to the 20-ketone and protecting groups were sequentially removed to give the first title hapten 1. The second route started from (20R)-19-hydroxy-3-oxopregn-4-en-20-yl acetate (11), which was hydrogenated in the presence of base to the 5beta-pregnan-3-one derivative 12, protected in position 19 with tert-butyldimethylsilyl group and reduced with borohydride. The prevailing 3alpha-alcohol 15 was separated, protected in position 3 with a methoxymethyl group, deprotected in position 19 and transformed into the 19-[O-(carboxymethyl)oxime] 19. After deacetylation, esterification with diazomethane and oxidation in position 20, the pregnanolone skeleton was regenerated. Final deprotection steps gave the second title hapten 2. Both haptens, i.e., (19E)-3beta- and -3alpha-hydroxy-20-oxo-5beta-pregnan-19-al 19-[O-(carboxymethyl)oxime], were designed for the development of immunoassays of the corresponding parent neuroactive steroids.


Assuntos
Haptenos/química , Oximas/síntese química , Pregnanolona/química , Conformação Molecular , Oximas/química , Estereoisomerismo
9.
Alcohol Clin Exp Res ; 29(6): 1010-7, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15976527

RESUMO

BACKGROUND: Alcohol abuse is associated with menstrual irregularities related to the inhibition of progesterone secretion involved in regulation of the menstrual cycle. Reduced progesterone metabolites, including pregnanolone isomers (PIs), are efficient neuromodulators. The authors attempted to evaluate whether levels of PIs reflect impairment in progesterone biosynthesis in premenopausal women treated for alcohol addiction and whether alcohol detoxification therapy contributes to the restoration of their reproductive functions and psychosomatic stability by influencing steroid biosynthesis. METHODS: Serum allopregnanolone (3alpha-hydroxy-5alpha-pregnan-20-one; P3alpha5alpha), pregnanolone (P3alpha5beta), isopregnanolone (P3beta5alpha), epipregnanolone (P3beta5beta), progesterone, pregnanolone sulfate (PregS), pregnanolone, and estradiol were measured in 20 women during therapy (at start, three days, 14 days, one month, and four months) by gas chromatography-mass spectrometry or radioimmunoassay. The results were evaluated by a linear mixed model for longitudinal data, with stage of the treatment and subject as categorical factors, phase of the menstrual cycle as a time-varying covariate, and age of the subject as a covariate and by regression in individual stages of the menstrual cycle. RESULTS: During detoxification treatment, progesterone increased in the luteal phase. P3alpha5alpha, P3beta5alpha, and P3beta5beta rose in both phases of the menstrual cycle. DISCUSSION: Given the similar mechanism in the effects of alcohol and steroids in activating gamma-aminobutyric acid A receptors, the restoration of progesterone and PIs during therapy could be explained by an adaptation to increasing requests for gamma-aminobutyric acid A-receptor activating substances owing to the cessation of alcohol intake or by the regeneration of progesterone formation. In conclusion, the reinstatement of progesterone, P3alpha5alpha, and P3beta5beta serum levels demonstrates the favorable effect of detoxification therapy on both reproductive functions and the psychosomatic stability of premenopausal women treated for alcohol addiction.


Assuntos
Alcoolismo/tratamento farmacológico , Pregnanolona/sangue , Pré-Menopausa/metabolismo , Progesterona/sangue , Adulto , Alcoolismo/reabilitação , Estradiol/sangue , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Modelos Lineares , Estudos Longitudinais , Ciclo Menstrual/sangue , Ciclo Menstrual/metabolismo , Pessoa de Meia-Idade , Pregnanolona/metabolismo , Pré-Menopausa/sangue , Progesterona/metabolismo , Radioimunoensaio , Análise de Regressão , Resultado do Tratamento
10.
Steroids ; 70(8): 515-24, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15894035

RESUMO

Long-term alcohol consumption results in menstrual irregularities due to the inhibition of progesterone secretion. Some progesterone metabolites, including three pregnanolone isomers (PI), abate, while pregnenolone sulfate (PregS) and dehydroepiandrosterone sulfate (DHEAS) increase, alcohol tolerance. The rationale of this study was to evaluate how the neuroactive steroids reflect the impaired progesterone formation in premenopausal women treated for alcohol addiction, and whether detoxification therapy could restore female reproductive functions and psychosomatic stability by reinstatement of the steroid biosynthesis. Accordingly, serum allopregnanolone (3alpha-hydroxy-5alpha-pregnan-20-one (P3alpha5alpha)), pregnanolone (P3alpha5beta), isopregnanolone (P3beta5alpha) and epipregnanolone (P3beta5beta), progesterone, PregS, pregnenolone, 17alpha-hydroxy-pregnenolone (Preg17), 17alpha-hydroxy-progesterone (Prog17), DHEA, DHEAS, cortisol and estradiol were measured in 20 women during the therapy (start, 3 days, 14 days, 1 month, 4 months), and in 17 controls, using GC-MS or RIA and evaluated by age-adjusted ANCOVA with status and phase of the menstrual cycle (PMC) as factors, and status-PMC interaction. The patients exhibited depressed progesterone, Prog17, PI, and estradiol, a decreased progesterone/pregnenolone ratio, a decreased ratio of neuroinhibiting P3alpha5alpha to neuroactivating PregS, and an elevated PregS and PregS/pregnenolone ratio. The treatment mostly restored the indices. The reduction of neuroinhibiting pregnanolone isomers in the patients is primarily associated with the impairment in ovarian steroid biosynthesis. Nevertheless, changes in enzyme activities connected with the formation of PI and the influence of altered physiological requirements on the balance between endogenous neuroinhibiting and neuroactivating steroids are also likely. The reinstatement of serum estradiol, progesterone, and PI during the therapy demonstrates its favorable effect on both reproductive functions and the psychosomatic stability of the patients.


Assuntos
Alcoolismo/tratamento farmacológico , Pregnanolona/análogos & derivados , Pré-Menopausa/sangue , Pré-Menopausa/fisiologia , Esteroides/metabolismo , Desidroepiandrosterona/sangue , Desidroepiandrosterona/química , Desidroepiandrosterona/metabolismo , Sulfato de Desidroepiandrosterona/sangue , Sulfato de Desidroepiandrosterona/química , Sulfato de Desidroepiandrosterona/metabolismo , Estradiol/sangue , Estradiol/química , Estradiol/metabolismo , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Hidrocortisona/sangue , Hidrocortisona/metabolismo , Pregnanolona/sangue , Pregnanolona/química , Pregnanolona/metabolismo , Pregnenolona/sangue , Pregnenolona/química , Pregnenolona/metabolismo , Pré-Menopausa/efeitos dos fármacos , Progesterona/sangue , Progesterona/química , Progesterona/metabolismo , Radioimunoensaio , Estereoisomerismo , Esteroides/sangue , Esteroides/química , Fatores de Tempo
11.
Steroids ; 70(9): 615-25, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15907964

RESUMO

Linear oligoesters based on etienic acid (3beta-hydroxyandrost-5-ene-17beta-carboxylic acid) containing four steroid units were prepared using a 2+2 synthetic strategy in a successful synthesis of 3beta-{[3beta-({3beta-[(3beta-hydroxyandrost-5-ene-17beta-carbonyl)oxy]androst-5-ene-17beta-carbonyl}oxy)androst-5-ene-17beta-carbonyl]oxy}androst-5-ene-17beta-carboxylic acid. The main problems with deprotection were overcome by using orthogonal groups as O-nitrates and 2-(trimethylsilyl)ethyl ethers.


Assuntos
Androstenos/química , Polímeros/síntese química , Esterificação , Ésteres/química , Géis/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Polímeros/química , Espectrofotometria Infravermelho
12.
J Steroid Biochem Mol Biol ; 96(2): 187-200, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15908198

RESUMO

7-Hydroxy-metabolites of dehydroepiandrosterone (DHEA) and 3beta,17beta-androstenediol (AD) possess immunomodulatory and neuroprotective properties; therefore, the measurement of these steroids in patients with autoimmune diseases or disturbances in the CNS may be of interest. A gas chromatography-mass spectrometry (GC-MS) method for the determination of 7-hydroxy-metabolites of pregnenolone, DHEA, AD, and testosterone including the parent steroids was applied to serum samples from 12 adult men (27-66 years), 13 male adolescents (13-20 years), 5 boys (6-10 years), 15 women in the follicular phase of the menstrual cycle (22-45 years), 17 women in the luteal phase (22-45 years), and 4 girls (6-10 years). The steroids were age and sex dependent, but independent of the menstrual cycle. The ratio of the 7alpha-hydroxy-metabolites to their parent steroids were age dependent, exhibiting an increasing trend (p < 0.0001, ANOVA) from pregnenolone (5%) to AD (20%). The ratio of 7beta- to 7alpha-metabolites ranged from 0.6 to 1. These results are consistent with models suggesting 7alpha-hydroxylation of the parent steroid, conversion to a 7-oxo-steroid and finally to the 7beta-hydroxylated-metabolite. Partial correlations suggested that 7-hydroxylation might reduce the concentration of circulating androgens. Despite the three times lower concentration of AD-metabolites, their antiglucocorticoid, immunomodulatory, and neuroprotective effects may be comparable to that of DHEA based on their reported greater biological activity.


Assuntos
Androstenodiol/análogos & derivados , Androstenodiol/sangue , Desidroepiandrosterona/análogos & derivados , Desidroepiandrosterona/sangue , Pregnenolona/análogos & derivados , Pregnenolona/sangue , Testosterona/análogos & derivados , Testosterona/sangue , Adolescente , Adulto , Criança , Feminino , Fase Folicular , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Hidroxilação , Masculino , Valores de Referência
13.
Steroids ; 70(11): 739-49, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15913684

RESUMO

Derivatives of 16alpha-hydroxy-dehydroepiandrosterone, which have an additional oxygen substituent at position 7 (oxo or hydroxy group), were synthesized. Firstly, 17,17-dimethoxyandrost-5-ene-3beta,16alpha-diyl diacetate was prepared and then oxidized with a complex of chromium(VI) oxide and 2,5-dimethylpyrazole to the respective 7-oxo derivative. This key intermediate was both deprotected or reduced by l-Selectride or sodium borohydride in the presence of cerium(III) chloride and then deprotected to give 7-oxo, 7alpha-hydroxy and 7beta-hydroxy derivatives of 16alpha-hydroxy-dehydroepiandrosterone. The target compounds were characterized by (1)H and (13)C NMR spectra and in the form of O-methyloxime-trimethylsilyl derivatives, by gas chromatography/mass spectrometry methods.


Assuntos
Desidroepiandrosterona/análogos & derivados , Cromatografia Gasosa-Espectrometria de Massas , Boroidretos , Cério , Cloretos , Desidroepiandrosterona/análise , Desidroepiandrosterona/química , Hidroxilação , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Oxirredução
14.
J Clin Endocrinol Metab ; 90(1): 395-403, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15486056

RESUMO

The pregnanolone isomers (PI) allopregnanolone (3alpha-hydroxy-5alpha-pregnan-20-one), pregnanolone (3alpha-hydroxy-5beta-pregnan-20-one), isopregnanolone (3beta-hydroxy-5alpha-pregnan-20-one), epipregnanolone (3beta-hydroxy-5beta-pregnan-20-one), progesterone, and estradiol were measured in 138 pregnant women. The sampling was carried out from the first through the 10th month of pregnancy. Gas chromatography-mass spectrometry analysis and RIA were used for the measurement of steroid levels. The ratios of individual PI were similar to those found previously around parturition: about 25:10:7:1 for allopregnanolone, pregnanolone, isopregnanolone, and epipregnanolone, respectively. All the PI showed a significant increase during pregnancy, which was more pronounced in the 3alpha-steroids. The results indicated changing ratios between 3alpha- and 3beta-PI and between 5alpha- and 5beta-PI throughout pregnancy. The constant allopregnanolone/isopregnanolone ratio found through pregnancy weakened the hypothesis of the role of isopregnanolone in the onset of parturition. The ratio of estradiol (stimulating uterine activity) to 5alpha-PI and epipregnanolone exhibited significant changes during pregnancy in favor of estradiol up to the sixth or seventh month, in contrast to the constant estradiol/pregnanolone ratio. A pregnancy-stabilizing role of pregnanolone, counterbalancing the stimulating effect of estradiol on the onset of parturition, was suggested.


Assuntos
Gravidez/sangue , Pregnanolona/sangue , Estradiol/sangue , Feminino , Idade Gestacional , Humanos , Isomerismo , Trabalho de Parto/sangue , Progesterona/sangue
15.
Steroids ; 69(10): 605-12, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15465104

RESUMO

3alpha,17beta-Dihydroxy-3beta-methyl-5alpha-androstan-6-one (1) and 3beta,17beta-dihydroxy-3alpha-methyl-5alpha-androstan-6-one (13) were prepared by the reaction of methylmagnesium bromide with the 3-ketosteroids. Structures and configurations in position 3 were determined by NMR spectra. Substitution in the position 6 influences the ratio of the products.


Assuntos
Androstano-3,17-diol/análogos & derivados , Androstanos/síntese química , Androstano-3,17-diol/síntese química , Androstano-3,17-diol/química , Androstanos/química , Androstenodiol/química , Cetosteroides/química , Espectroscopia de Ressonância Magnética , Metilação , Conformação Molecular , Estrutura Molecular
16.
Steroids ; 69(3): 161-71, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15072918

RESUMO

Deuterated analogs of pregnenolone and pregnenolone sulfate with three atoms of deuterium in position 19 were prepared. The synthetic approach was developed on derivatives of dehydroepiandrosterone, where initial intermediates were well characterized, and then applied to the pregnenolone series. Starting 19-hydroxy compounds were transformed into 3alpha,5-cycloderivatives to simplify the Jones oxidation into the corresponding 19-oic acids. After oxidation, rearrangement to 3-hydroxy-5-enes, and suitable protection, two deuterium atoms were introduced by lithium aluminum deuteride reduction. Mesylate exchange by iodide in the presence of zinc and deuterium oxide added third deuterium atom. Deprotection gave title analogs with about 93-95% content of d3-derivative, the rest was mainly not fully deuterated d2-analogue as followed from the mass spectra analysis. Thus, 3beta-hydroxy[19-2H3]androst-5-en-17-one was prepared in 14 steps from 19-hydroxy-17-oxoandrost-5-en-3beta-yl acetate in 8.9% yield, the analogous sequence in the pregnenolone series gave 3beta-hydroxy[19-2H3]pregn-5-en-20-one in 7.3% yield. Corresponding sulfates were prepared via pyridinium salts in 53 and 57% yields, respectively. Fully assigned NMR data of selected pregnenolone derivatives were given.


Assuntos
Desidroepiandrosterona/análogos & derivados , Desidroepiandrosterona/síntese química , Pregnanolona/análogos & derivados , Pregnanolona/síntese química , Pregnenolona/síntese química , Androstanos/química , Técnicas de Química Combinatória , Desidroepiandrosterona/química , Deutério/química , Estrutura Molecular , Pregnanolona/química , Pregnenolona/química
17.
Org Biomol Chem ; 1(19): 3458-63, 2003 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-14584811

RESUMO

A new saccharide receptor in protic media has been designed and synthesized. The receptor combines advantages of steroids, which are responsible for saccharide binding, and of the porphyrin moiety acting as a signalling component of the molecule due to changes in UV-vis electronic spectra. The synthesis is based on condensation of steroid aldehyde with pyrrole to form the porphyrin unit with four protected steroid moieties. After deprotection, meso-substituted porphyrin contains 12-hydroxy groups on the steroidal part. The receptor is soluble in aqueous solutions and exhibits high complexation affinity towards saccharides. Because the receptor extensively aggregates in water, most of the experiments were performed in 50% aqueous 2-propanol where aggregation is significantly eliminated. Binding is evidenced by spectral changes in the Soret region of the receptor in UV-vis absorption spectra allowing the evaluation of the binding constants. Additional confirmation of binding is obtained using 1H NMR, Raman and IR spectroscopies and the surface plasmon resonance technique. The receptor exhibits higher selectivity for oligosaccharides over monosaccharide. The results point to the importance of a combination of multiple binding via H-bonding and hydrophobic interactions.


Assuntos
Técnicas Biossensoriais , Carboidratos/análise , Proteínas de Transporte/síntese química , Proteínas de Transporte/metabolismo , Porfirinas/química , Receptores de Superfície Celular , Esteroides/química , Metabolismo dos Carboidratos , Espectroscopia de Ressonância Magnética , Maltose/análise , Maltose/metabolismo , Estrutura Molecular , Oligossacarídeos/análise , Oligossacarídeos/metabolismo , Espectrometria de Fluorescência , Espectrofotometria , Ressonância de Plasmônio de Superfície
18.
Steroids ; 68(2): 149-58, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12606006

RESUMO

Synthetic routes leading to 19E and 7Z O-(carboxymethyl)oximes derived from 16alpha-hydroxydehydroepiandrosterone were developed using two independent methods for introduction of the 16alpha-hydroxy group. Firstly, the oxime moiety was built, and then, either epoxidation of the enol acetate followed by the boron trifluoride mediated rearrangement or alkaline hydrolysis of the corresponding alpha-bromide in aqueous N,N-dimethylformamide were employed. The last step in both methods was removal of the protecting groups, which consisted of acid deprotection of the acetates and gentle alkaline hydrolysis of the methyl ester. Final haptens were designed as components for immunoanalytical kits.


Assuntos
Desidroepiandrosterona/química , Haptenos/química , Desidroepiandrosterona/análogos & derivados , Estrutura Molecular , Relação Estrutura-Atividade
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