RESUMEN
Recombinant human soluble thrombomodulin (rTM) is a new drug for the treatment of disseminated intravascular coagulation (DIC), although the effects on obstetric DIC have not yet been fully elucidated. We report herein three patients with obstetric DIC caused by placental abruption, hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome, and atonic bleeding, respectively. In all three cases, treatment with rTM proved successful, suggesting that rTM is an efficient method for treating obstetric DIC.
Asunto(s)
Coagulación Intravascular Diseminada/tratamiento farmacológico , Gabexato/administración & dosificación , Trombomodulina/administración & dosificación , Desprendimiento Prematuro de la Placenta , Adulto , Coagulación Intravascular Diseminada/etiología , Quimioterapia Combinada , Femenino , Síndrome HELLP , Hemólisis , Humanos , Embarazo , Proteínas Recombinantes/administración & dosificación , Solubilidad , Resultado del TratamientoRESUMEN
Sphingosine-1-phosphate (S1P) is an intracellular second messenger and an extracellular mediator through endothelial differentiation gene (EDG) receptors, which are a novel class of G-protein-coupled receptors. Although EDG has attracted much attention because of its various roles, no selective agonists or antagonists have yet been developed. This could account for the delay in clarifying the physiological roles of members of the EDG family. Because precise structural information on EDG receptors is not yet available, pharmacophore models were generated based on structural information for S1P using the rational drug design software Catalyst. Novel antagonists, 2-alkylthiazolidine-4-carboxylic acids, were retrieved from a three-dimensional database search using the pharmacophore models, and these showed activity for EDG3. On the basis of their nonphosphoric acid structure, more potent antagonists, 2-(m- or p-heptylphenyl)thiazolidine-4-carboxylic acid, were developed.
Asunto(s)
Proteínas de Unión al ADN/antagonistas & inhibidores , Proteínas I-kappa B , Lisofosfolípidos , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Tiazoles/síntesis química , Proteínas de Unión al ADN/metabolismo , Bases de Datos Factuales , Células HeLa , Humanos , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Conformación Molecular , Inhibidor NF-kappaB alfa , Relación Estructura-Actividad Cuantitativa , Receptores Lisofosfolípidos , Esfingosina/química , Esfingosina/farmacología , Estereoisomerismo , Tiazinas/síntesis química , Tiazinas/química , Tiazinas/farmacología , Tiazoles/química , Tiazoles/farmacologíaRESUMEN
The diastereoselective nucleophilic addition of alkyllithium to N-alkylidene-alpha-naphthylethylamine was carried out. In the presence of Lewis acids or Lewis bases, organolithiums reacted smoothly with imines to give the corresponding amines in high stereoselectivity (up to 100% de). Furthermore, the resulting optically active amines were found to be useful for asymmetric reactions as chiral ligands.
RESUMEN
An efficient synthesis of alpha,beta-unsaturated ketones by the reaction of acid chlorides with trialkylaluminum (1/3 mole equiv) in the presence of AlCl(3) (1 mol equiv) is described. Dialkylzincs were also useful and are easier to prepare than trialkylaluminum. Reaction of RCOCl with R'AlCl(2) or R'(2)AlCl gave R'COR, without AlCl(3), in high yield.
RESUMEN
The first example of a reagent-controlled enantioselective Pictet-Spengler reaction is demonstrated. Using diisopinocampheylchloroborane as a chiral Lewis acid catalyst, the Pictet-Spengler reaction of N(b)-hydroxytryptamine with aldehydes gave the corresponding 2-hydroxytetrahydro-beta-carbolines in up to 90% ee. The enantioselective Pictet-Spengler reaction catalyzed by chiral binaphthol-derived Brønsted acid-assisted Lewis acids, with up to 91% ee, is also demonstrated.
RESUMEN
The manzamine alkaloids such as manzamine A, B, and C belongs to a unique family of cyctotoxic beta-carbline linked azacycles, which have been isolated from several marine sponges. Manzamine A has recently been shown to exhibit in vivo antimalarial activity against parasite Plasmodium berghei. Further progress was added recently by the isolation of the new and closely related members such as nakadomarin A, as well as an ingenious proposal for their biosynthetic pathway. Martefragin A, isolated from the Japan sea alga Martensia fragilis Harvey, has been shown to have a potent inhibitory activity against lipid peroxidation. Our recen, efforts to develop total synthesis entries to manzamine A, manzamine B, manzamine C, nakadomarin A, and martefragin A are presented.
Asunto(s)
Alcaloides Indólicos/síntesis química , Alcaloides/síntesis química , Alcaloides/química , Alcaloides/farmacología , Animales , Antimaláricos/síntesis química , Antimaláricos/química , Antimaláricos/farmacología , Carbazoles , Eucariontes/química , Técnicas In Vitro , Alcaloides Indólicos/química , Indoles/síntesis química , Indoles/química , Indoles/farmacología , Peroxidación de Lípido/efectos de los fármacos , Biología Marina , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Estructura Molecular , Plasmodium berghei/efectos de los fármacos , Pirroles/síntesis química , Pirroles/química , Pirroles/farmacología , RatasRESUMEN
Synthetic study of biologically important nitrogen-containing natural products and development of new methodologies and design of leading compounds for new pharmaceuticals are described. The first total synthesis of eudistomines, manzamine C, martefragin A, cerebroside B1b, and symbioramide was accomplished and the absolute configurations of the stereogenic centers were determined. A novel methodology useful for the synthesis of alkaloids that have perhydroisoquinoline ring system such as manzamine A and B, and related alkaloids, nakadomarin A and dynemicin A, is presented. Sphingolipids, 4-stereoisomers of 1-phenyl-2-palmitoylamino-3-morpholino-1-propanol, were synthesized and antimalaria activity was investigated. Inhibition of DNA primase by sphingosine and its analogues is described. A new synthetic methodology for alkylation and reduction of imines has been developed, and the first example of a reagent-controlled enantioselective Pictet-Spengler reaction is described. Also novel and convenient methods using transition metal and rare earth metals including alkene metathesis, asymmetric Diels-Alder reaction, imino ene reaction, selective allylic halogenation, enantioselective Pictet-Spengler reaction, and enantioselective physostigmine synthesis are described.
Asunto(s)
Alcaloides/síntesis química , Carbolinas/síntesis química , Diseño de Fármacos , Iminas/síntesis química , Indoles/síntesis química , Nitrógeno , Pirroles/síntesis química , Esfingolípidos/síntesis química , Alcaloides/química , Carbolinas/química , Química Orgánica/métodos , Química Farmacéutica/métodos , Iminas/química , Indoles/química , Pirroles/química , Esfingolípidos/químicaRESUMEN
Non-metathesis reactions of ruthenium carbene catalysts, such as olefin isomerization, hydrogenation, radical reaction, activation of silane, cyclopropanation, epimerization cocyclopropane, [3 + 2] cycloaddition, and cycloisomerization, are summarized. The utility of these reactions was demonstrated by the synthesis of indole using olefin isomerization and subsequent ring-closing metathesis, the synthesis of indoline using cycloisomerization, and the synthesis of the putative structure of fistulosin using cycloisomerization as a key step.
Asunto(s)
Compuestos Heterocíclicos/química , Metano/análogos & derivados , Nitrógeno/química , Compuestos de Rutenio/química , Alquenos/química , Catálisis , Ciclización , Ciclopropanos/química , Radicales Libres/química , Compuestos Heterocíclicos/síntesis química , Hidrocarburos/química , Hidrogenación , Indoles/síntesis química , Indoles/química , Isomerismo , Metano/química , Estructura Molecular , Silanos/químicaRESUMEN
A pure ruthenium hydride complex with N-heterocyclic carbene (NHC) ligand was efficiently generated from the reaction of a second-generation Grubbs ruthenium catalyst with vinyloxytrimethylsilane and unambiguously characterized. This ruthenium hydride complex showed high catalytic activity for the selective isomerization of terminal olefin and for the cycloisomerization of 1,6-dienes. These reactions of N-allyl-o-vinylaniline lead to novel synthetic methods for heterocycles such as indoles and 3-methylene-2,3-dihydroindoles, which are useful synthons for bioactive natural products. These procedures address an important issue in diversity-oriented synthesis.
Asunto(s)
Compuestos Heterocíclicos/química , Metano/análogos & derivados , Compuestos Organometálicos/química , Rutenio/química , Hidrocarburos/química , Isomerismo , Metano/química , Estructura MolecularRESUMEN
A novel combined system of Yb(OTf)(3) with TMSCl or TMSOTf catalyzed an imino ene reaction. The reaction of N-tosylbenzaldimine (1) with alpha-methylstyrene (2) proceeded smoothly to give homoallylic amine 3 in the presence of a catalytic amount of Yb(OTf)(3) and TMSCl. This catalytic system was successfully applied to the imino ene reactions of various aldimines with alkenes. This new imino ene reaction provides a unique method for the three-component coupling reaction of an aldehyde, tosylamide, and alpha-methylstyrene in the presence of Yb(OTf)(3) and TMSOTf, to give the corresponding homoallylic amine.
RESUMEN
(-)-Nakadomarin A is a member of manzamine alkaloid isolated from a marine sponge and have a unique hexacyclic structure. The first total synthesis of (+)-nakadomarin A, an enantiomer of natural product, has been accomplished from stereochemically defined 4-oxopiperidin-3-carboxylic acid derivative. The synthesis established the structure of nakadomarin A including absolute configuration.
Asunto(s)
Alcaloides/síntesis química , Carbolinas/síntesis química , Animales , Furanos/síntesis química , Conformación Molecular , Poríferos/químicaRESUMEN
We radiographically investigated 36 hips in 34 patients with osteoarthritis of the hip who had undergone total hip arthroplasty. Their mean age was 59.2 years (range 36-79 years), and the mean follow-up period was 11.2 years (range 10-14 years). The long-term outcome and the chronological changes in the bulk autograft were examined. The acetabular component of the prosthesis was a Lord-type threaded cup with a smooth surface. At follow-up, bone absorption was minor in 17 joints, moderate in 11, and major in 8. The hips with graft coverage of >==20% (group A) had a significantly higher loosening rate than hips with coverage of <<20% (group B) ( P << 0.05). The cup position changed markedly in group A. Our findings indicate that graft coverage should be less than 20% when a bulk graft is used together with a smooth-surfaced cementless cup.
Asunto(s)
Artroplastia de Reemplazo de Cadera , Trasplante Óseo , Fémur/trasplante , Prótesis de Cadera , Acetábulo/patología , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis de la Cadera/cirugíaRESUMEN
We investigated risk factors for osteonecrosis of the femoral head (ONF) in renal transplant recipients, who are susceptible to the disease. Among 287 renal transplant recipients, 18 ONF patients with enough data were included, and 18 age- and sex-matched recipients without ONF were nominated as reference cases. Risk factors were analyzed using a conditional logistic regression method. There were no differences between the ONF patients and the reference cases regarding the types of immunosuppressant or the donor (living or cadaveric, father or mother, matching blood type and human leukocyte antigens). The daily oral steroid dosage (prednisolone 25.0 mg/day or more) and blood urea nitrogen level 2 months after transplantation were the only factors with relevance to the occurrence of ONF. We propose that oral steroid dosages should be low or reduced after renal transplantation, and acute rejection should be controlled with pulsed therapy.