RESUMEN
The Suzuki-Miyaura cross-coupling protocol was applied to the synthesis of 1a, the C-glycoside analogue of PsA methyl ether. This marks the first construction of a C-glycoside for this class of marine natural products, thereby offering an opportunity to compare its bioactivity to the natural substances. Its activity profile resembled that of PsA (1) and PsA O-methyl ether (1b) when assayed for its anti-inflammatory activity and its ability to inhibit phagocytosis. We conclude that the intact structure is present when a pseudopterosin expresses its anti-inflammatory and phagocytosis inhibitory properties and that they are, therefore, not likely to be prodrugs. Results show that 1a is an effective binding agent toward the A2A and A3 adenosine receptors, displaying IC50 values of 20 and 10 microM, respectively.
Asunto(s)
Antiinflamatorios/farmacología , Diterpenos/farmacología , Glicósidos/síntesis química , Glicósidos/farmacología , Éteres Metílicos/farmacología , Tetrahymena thermophila/efectos de los fármacos , Animales , Antiinflamatorios/síntesis química , Antiinflamatorios/química , Unión Competitiva/efectos de los fármacos , Línea Celular , Diterpenos/química , Relación Dosis-Respuesta a Droga , Glicósidos/química , Humanos , Éteres Metílicos/química , Ratones , Modelos Moleculares , Conformación Molecular , Pruebas de Sensibilidad Parasitaria , Fagocitosis/efectos de los fármacos , Receptor de Adenosina A2A/efectos de los fármacos , Receptor de Adenosina A3/efectos de los fármacos , Estereoisomerismo , Relación Estructura-Actividad , Tetrahymena thermophila/citologíaRESUMEN
We (a) describe the completion of a total synthesis of 7,11-epi-thyrsiferol (4), (b) compare the antimitotic activities of thyrsiferol (2), Delta15,28-dehydrothyrsiferol (3), and 7,11-epi-thyrsiferol (4), (c) evaluate the synergistic behavior of the title compound and colchicine to inhibit cell proliferation, and (d) describe the results of conformational searches that provide additional insight concerning the SAR profile of the thyrsiferol family of natural products.
Asunto(s)
Antimitóticos/síntesis química , Antimitóticos/farmacología , Furanos/síntesis química , Furanos/farmacología , Modelos Biológicos , Piranos/síntesis química , Piranos/farmacología , Animales , Antimitóticos/química , Colchicina/química , Colchicina/farmacología , Furanos/química , Modelos Moleculares , Estructura Molecular , Piranos/química , Strongylocentrotus purpuratus/citología , Strongylocentrotus purpuratus/efectos de los fármacos , Strongylocentrotus purpuratus/enzimología , Relación Estructura-ActividadAsunto(s)
Inhibidores Enzimáticos/farmacología , Indoles/farmacología , Inflamación/enzimología , Inflamación/patología , Fenoles/farmacología , Inhibidores de Proteínas Quinasas , Animales , Proteínas de Ciclo Celular , División Celular/efectos de los fármacos , Cianobacterias/química , Endotelio Vascular/citología , Humanos , Indoles/uso terapéutico , Inflamación/tratamiento farmacológico , Isoenzimas/antagonistas & inhibidores , Masculino , Ratones , Fenoles/uso terapéutico , Pigmentos Biológicos , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C beta , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas , Proteínas Recombinantes , Venas Umbilicales , Quinasa Tipo Polo 1RESUMEN
A protein expressing phospholipase A2 activity was purified from the granular amebocyte of the horseshoe crab, Limulus polyphemus by cation-exchange, size-exclusion chromatography and semi-preparative reverse-phase-high pressure liquid chromatography (RP-HPLC). The protein had an apparent mass of 17.7 kDa by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), but a more accurate estimate of 18.5 kDa was assigned by electrospray ionization-mass spectrometry (ESI-MS). A partial sequence of this protein demonstrated total sequence homology with an 18.5 kDa protein with cell aggregating properties from Limulus reported by Fujii et al. [J. Biol. Chem. 267:22452.]. In these studies, the Limulus protein demonstrated a positive cross-reaction to polyclonal anti-human recombinant phospholipase A2 (group II, 14 kDa). The protein did not display a significant loss of biological activity after boiling, but all enzymatic activity was lost after boiling in the presence of the reducing agent betamercaptoethanol (beta-mercaptoethanol). The Limulus protein was inhibited by manoalide, a covalent irreversible phospholipase A2 inhibitor, in a dose-dependent fashion with 50% inhibition occurring at a concentration of 0.48 microM. The Limulus protein displayed no activity in a triglyceride lipase assay. These studies characterize an alternative phospholipase A2 activity for the previously described 18.5 kDa protein from the L. polyphemus amebocyte.
Asunto(s)
Moléculas de Adhesión Celular/química , Fosfolipasas A/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas de Artrópodos , Western Blotting , Cationes , Moléculas de Adhesión Celular/aislamiento & purificación , Moléculas de Adhesión Celular/metabolismo , Cromatografía en Agarosa , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Disulfuros , Relación Dosis-Respuesta a Droga , Electroforesis en Gel de Poliacrilamida , Escherichia coli/metabolismo , Femenino , Fluorometría , Hemaglutinación , Cangrejos Herradura , Calor , Humanos , Lipasa/metabolismo , Masculino , Mercaptoetanol/farmacología , Datos de Secuencia Molecular , Inhibidores de Fosfodiesterasa/farmacología , Fosfolipasas A2 , Proteínas Recombinantes/metabolismo , Sustancias Reductoras/farmacología , Análisis de Secuencia de Proteína , Homología de Secuencia de Aminoácido , Espectrometría de Masa por Ionización de Electrospray , Terpenos/farmacología , Factores de TiempoRESUMEN
A specimen of Plakortis lita from Palau yielded the new carboxylic acids, homo-plakotenin (2a), the sodium salt of homo-plakotenin (2b), the sodium salt of nor-plakotenin (3), the sodium salt of plakotenin (1b), and the known compound plakotenin (1a). The structures of the new acids were elucidated by interpretation of spectral data and by comparison with the known compound. Compounds 1a, 1b, and 2a were found to significantly reduce proliferation of rheumatoid synovial fibroblasts.
Asunto(s)
Antirreumáticos/aislamiento & purificación , Ácidos Carboxílicos/aislamiento & purificación , Poríferos/química , Animales , Antirreumáticos/farmacología , Ácidos Carboxílicos/farmacología , Cromatografía Líquida de Alta Presión , Fibroblastos , Humanos , Palau , Enfermedades Reumáticas/patología , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Timidina/metabolismoRESUMEN
Part of the challenge of macromolecular crystal growth for structure determination is obtaining crystals with a volume suitable for x-ray analysis. In this respect an understanding of the effect of solution conditions on macromolecule nucleation rates is advantageous. This study investigated the effects of supersaturation, temperature, and pH on the nucleation rate of tetragonal lysozyme crystals. Batch crystallization plates were prepared at given solution concentrations and incubated at set temperatures over 1 week. The number of crystals per well with their size and axial ratios were recorded and correlated with solution conditions. Crystal numbers were found to increase with increasing supersaturation and temperature. The most significant variable, however, was pH; crystal numbers changed by two orders of magnitude over the pH range 4.0-5.2. Crystal size also varied with solution conditions, with the largest crystals obtained at pH 5.2. Having optimized the crystallization conditions, we prepared a batch of crystals under the same initial conditions, and 50 of these crystals were analyzed by x-ray diffraction techniques. The results indicate that even under the same crystallization conditions, a marked variation in crystal properties exists.
Asunto(s)
Concentración de Iones de Hidrógeno , Muramidasa/química , Animales , Pollos , Cristalografía por Rayos X/métodos , Microscopía por Video/métodos , Soluciones , Temperatura , TermodinámicaRESUMEN
The phospholipid composition was determined for the amebocyte of the primitive arthropod Limulus polyphemus. The total fatty acid composition of the cells' lipids was analyzed by gas chromatography/mass spectrometry (GC/MS) of fatty acid methyl esters (FAME). The FAME analysis revealed high levels of 20-carbon polyunsaturated fatty acids (PUFA), especially arachidonic (20:4n-6) and eicosapentaenoic (20:5n-3) acids. Almost 20% of the total lipid profile was comprised of dimethyl acetals of 16- to 20-carbon chain lengths, indicative of plasmalogens in the phospholipid pool. Phospholipids, analyzed by high-pressure liquid chromatography, included phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI), sphingomyelin (SPH), and cardiolipin (CL). PE and PC levels predominated at 42.2 and 36.3%, respectively. Smaller amounts of PS (9.0%) and PI (6.2%) were present, as well as low levels of SPH (4.6%), CL (1.6%), and trace amounts of lysophosphatidylcholine. The major phospholipid species, PE, PC, PS and PI, were collected and their molecular species were examined by electrospray-ionization mass spectrometry. The molecular species within the phospholipid classes reflected the high levels of PUFA seen in the total lipid profile. PI was mainly composed of 18:0a/20:4. Over half of the PS consisted of 18:0a/18:1 and 18:0a/20:4. The major PE species were 20:1p/20:5, 20:1p/20:4, 18:0p/20:5, and 18:0p/20:4. PC had the largest distribution of molecular species, and its most abundant species were 16:0e/20:5, 16:0e/20:4, and 16:0p/20:4. The presence of 16:0e/20:4 is the first documentation of a specific precursor to platelet-activating factor in an invertebrate hemocyte. Note: at the sn-1 position: [a=1=O-acyl, e = 1-O-alkylether, and p = 1-O-alk-1'-enyl (plasmalogen)].
Asunto(s)
Ácidos Grasos/análisis , Cangrejos Herradura/química , Fosfolípidos/sangre , Fosfolípidos/química , Animales , Cardiolipinas/análisis , Cromatografía de Gases , Cromatografía Líquida de Alta Presión , Ácidos Grasos/metabolismo , Lisofosfatidilcolinas/análisis , Espectrometría de Masas/métodos , Fosfolípidos/clasificación , Esfingomielinas/análisisRESUMEN
Pseudopterosin E (PSE), a C-10 linked fucose glycoside and pseudopterosin A (PSA), a C-9 xylose glycoside isolated from the marine gorgonian Pseudopterogorgia elisabethae were both effective in reducing PMA-induced mouse ear edema when administered topically (ED50 (microg/ear) PSE(38), PSA(8)) or systemically (ED50 (mg/kg, i.p.) PSE (14), PSA (32)). Both compounds exhibited in vivo analgesic activity in phenyl-p-benzoquinone-induced writhing (ED50 (mg/kg, i.p.) PSE(14), PSA(4). PSE inhibited zymosan-induced writhing (ED50 = 6 mg/kg, i.p.), with a concomitant dose-dependent inhibition of peritoneal exudate 6-keto-prostaglandin F1alpha (ED50 = 24 mg/kg) and leukotriene C4 (ED50 = 24 mg/kg). In vitro, the pseudopterosins were inactive as inhibitors of phospholipase A2, cyclooxygenase, cytokine release, or as regulators of adhesion molecule expression. PSA inhibited prostaglandin E2 and leukotriene C4 production in zymosan-stimulated murine peritoneal macrophages (IC50 = 4 microM and 1 microM, respectively); however, PSE was much less effective. These data suggest that the pseudopterosins may mediate their anti-inflammatory effects by inhibiting eicosanoid release from inflammatory cells in a concentration and dose-dependent manner.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Cnidarios/química , Diterpenos/farmacología , Glicósidos/farmacología , Animales , Antiinflamatorios no Esteroideos/aislamiento & purificación , Línea Celular , Citocinas/metabolismo , Diterpenos/aislamiento & purificación , Edema/inducido químicamente , Edema/prevención & control , Eicosanoides/metabolismo , Glicósidos/aislamiento & purificación , Humanos , Macrófagos Peritoneales/efectos de los fármacos , Ratones , Neutrófilos/efectos de los fármacos , Neutrófilos/metabolismo , Dimensión del Dolor/efectos de los fármacosAsunto(s)
Artritis Reumatoide/metabolismo , Hipoxia de la Célula , Dinoprostona/biosíntesis , Membrana Sinovial/metabolismo , Animales , Células Cultivadas , Factores de Crecimiento Endotelial/metabolismo , Fibroblastos/metabolismo , Humanos , Interleucina-1/farmacología , Linfocinas/metabolismo , Masculino , Oxígeno/farmacología , Fosfolipasas A/metabolismo , Prostaglandina-Endoperóxido Sintasas/metabolismo , Proteínas Recombinantes , Vesículas Seminales/enzimología , Ovinos , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial VascularRESUMEN
This case report presents a patient with an adrenal pheochromocytoma manifesting as intestinal ischemia. Emergency department and hospital courses are described. Complications of pheochromocytoma are briefly reviewed, with special reference to the gastrointestinal findings in this syndrome. The onset of gastrointestinal symptoms in patients with pheochromocytoma can be a herald of intestinal ischemia, necessitating prompt medical and surgical intervention.