RESUMEN
Citrus pectin (CP), a polysaccharide composed of [â4)-α-D-GalpA-(1â]n, was submitted to one or four carboxy-reduction cycles, resulting in CP-CR1 and CP-CR4, which had 40% and 2% of GalpA units, respectively. The polysaccharides were chemically sulfated and their anticoagulant and antithrombotic effects determined. Sulfated polysaccharides (CP-S, CP-CR1S and CP-CR4S) had different anticoagulant activities, doubling APTT at concentrations of 28.7, 13.2, and 4.9 µg/ml respectively. CP-CR1S and CP-CR4S also showed antithrombotic activity in vivo with ED50 of 3.01 and 1.70 mg/kg, respectively. Like heparin, they inhibited thrombin by a mechanism dependent on AT and HCII. Their hemorrhagic potential was also similar to that of heparin. According to methylation analysis, 91.1% and 50.2% of 6-O-position in CP-CR4S and CP-CR1S were sulfated, respectively. Therefore, substitution of carboxyl groups by sulfate esters in these polysaccharides increases the anticoagulant and antithrombotic effects.
Asunto(s)
Anticoagulantes , Coagulación Sanguínea/efectos de los fármacos , Citrus sinensis/química , Fibrinolíticos , Pectinas , Polisacáridos , Animales , Anticoagulantes/química , Anticoagulantes/aislamiento & purificación , Anticoagulantes/farmacología , Femenino , Fibrinolíticos/química , Fibrinolíticos/aislamiento & purificación , Fibrinolíticos/farmacología , Masculino , Pectinas/química , Pectinas/aislamiento & purificación , Pectinas/farmacología , Polisacáridos/química , Polisacáridos/aislamiento & purificación , Polisacáridos/farmacología , Ratas , Ratas WistarRESUMEN
INTRODUCTION: A mannogalactan from Pleurotus ostreatoroseus (MgPr) was chemically sulfated to give MgPr-S1, which was evaluated for its anticoagulant and antithrombotic activities, bleeding tendency, and platelet aggregation. MATERIALS AND METHODS: MgPr-S1 was partially characterized by HPSEC-MALLS, methylation analysis, and 13C NMR spectroscopy. Its anticoagulant activity was determined by assays of aPTT, TT, alpha-thrombin and factor Xa residual activity, heparin cofactor II (HCII)-, or antithrombin (AT)-mediated inhibition. The antithrombotic effect was evaluated in rats using a venous thrombosis model and the bleeding tendency was also tested in vivo. Platelet aggregation was investigated by an adaptation of the method of Born [1]. RESULTS: The hydroxyl groups of beta-D-Manp units and OH-2 and OH-4 of the (1-->6)-linked alpha-D-Galp units were preferentially substituted. The anticoagulant activity of MgPr-S1 was mainly by thrombin inhibition with antithrombin and HCII, and had an effect on platelet aggregation induced by ADP and alpha-thrombin. It almost completely inhibited thrombus formation in vivo at a dose of 6 mg/kg and heparin inhibited thrombus formation at a dose of 0.200 mg/kg. CONCLUSIONS: These results suggested that the chemically sulfated mannogalactan could act as an alternative to heparin as anticoagulant.
Asunto(s)
Anticoagulantes/farmacología , Proteínas Antitrombina/metabolismo , Coagulación Sanguínea/efectos de los fármacos , Fibrinolíticos/farmacología , Galactanos/farmacología , Cofactor II de Heparina/metabolismo , Sulfatos/farmacología , Trombina/antagonistas & inhibidores , Animales , Anticoagulantes/aislamiento & purificación , Anticoagulantes/toxicidad , Tiempo de Sangría , Cromatografía en Gel , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Factor Xa/metabolismo , Inhibidores del Factor Xa , Femenino , Fibrinolíticos/aislamiento & purificación , Fibrinolíticos/toxicidad , Galactanos/aislamiento & purificación , Galactanos/toxicidad , Hemorragia/inducido químicamente , Humanos , Espectroscopía de Resonancia Magnética , Masculino , Tiempo de Tromboplastina Parcial , Agregación Plaquetaria/efectos de los fármacos , Pleurotus/química , Tiempo de Protrombina , Ratas , Ratas Wistar , Dispersión de Radiación , Relación Estructura-Actividad , Sulfatos/aislamiento & purificación , Sulfatos/toxicidad , Trombina/metabolismo , Trombosis de la Vena/sangre , Trombosis de la Vena/prevención & controlRESUMEN
Fucogalactans from Agaricus brasiliensis (EPF-Ab) and A. bisporus var. hortensis (EPF-Ah) were prepared via by aqueous extraction and a purification procedure. EPF-Ab had M(w) 19.4 x 10(3)g/mol and EPF-Ah M(w) 31.1 x 10(3)g/mol. EPF-Ab had a (1-->6)-linked alpha-D-Galp main-chain partially substituted in O-2 by non-reducing end-units of alpha-L-Fucp. EPF-Ah had a similar main-chain with O-2 substitution, but was partially methylated at HO-3, as well as having 2.5% non-reducing end-units of beta-D-Gal. In mice, EPF-Ab gave 39% antinociceptive inhibition (ID(50)>100mg/kg) and no anti-inflammatory activity. EPF-Ah also gave an inhibition of 39% at ID(50) 0.33 mg/kg and also inhibited by 61% (ID(50) 5.0mg/kg) total cell migration and by 32% peritoneal capillary permeability, which is related to the anti-inflammatory effect. The small differences in chemical structure in these polysaccharides thus modified their biological activities.
Asunto(s)
Agaricus/metabolismo , Analgésicos/administración & dosificación , Antiinflamatorios/administración & dosificación , Galactanos/administración & dosificación , Inflamación/tratamiento farmacológico , Dolor/tratamiento farmacológico , Extractos Vegetales/farmacología , Analgésicos/química , Animales , Antiinflamatorios/química , Frutas/metabolismo , Galactanos/química , Inflamación/diagnóstico , Masculino , Ratones , Dolor/diagnóstico , Resultado del TratamientoRESUMEN
Evaluated were the anticoagulant and antithrombotic activities, and bleeding effect of two chemically sulfated polysaccharides, obtained from citric pectin, with different average molar masses. Both low-molecular-weight (Pec-LWS, 3,600 g/mol) and high-molecular-weight sulfated pectins (Pec-HWS, 12,000 g/mol) had essentially the same structure, consisting of a (1-->4)-linked alpha-D-GalpA chain with almost all its HO-2 and HO-3 groups substituted by sulfate. Both polysaccharides had anticoagulant activity in vitro, although Pec-HWS was a more potent antithrombotic agent in vivo, giving rise to total inhibition of venous thrombosis at a dose of 3.5 mg/kg body weight. Surprisingly, in contrast with heparin, Pec-HWS and Pec-LWS are able to directly inhibit alpha-thrombin and factor Xa by a mechanism independent of antithrombin (AT) and/or heparin co-factor II (HCII). Moreover, Pec-HWS provided a lower risk of bleeding than heparin at a dose of 100% effectiveness against venous thrombosis, indicating it to be a promising antithrombotic agent.
Asunto(s)
Anticoagulantes/farmacología , Coagulación Sanguínea/efectos de los fármacos , Citrus sinensis , Fibrinolíticos/farmacología , Pectinas/farmacología , Sulfatos/farmacología , Trombosis de la Vena/prevención & control , Animales , Anticoagulantes/química , Anticoagulantes/aislamiento & purificación , Anticoagulantes/toxicidad , Citrus sinensis/química , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Inhibidores del Factor Xa , Femenino , Fibrinolíticos/química , Fibrinolíticos/aislamiento & purificación , Fibrinolíticos/toxicidad , Hemorragia/inducido químicamente , Humanos , Masculino , Peso Molecular , Pectinas/química , Pectinas/aislamiento & purificación , Pectinas/toxicidad , Agregación Plaquetaria/efectos de los fármacos , Ratas , Ratas Wistar , Relación Estructura-Actividad , Sulfatos/química , Sulfatos/aislamiento & purificación , Sulfatos/toxicidad , Trombina/antagonistas & inhibidores , Trombosis de la Vena/sangreRESUMEN
Glucans of basidiomycetes are considered to be an important class of polysaccharides, as they can act as biological response modifiers. We now isolate a gel-forming, water-soluble beta-glucan, with a molecular mass of 1.2 x 10(6)g/mol (HPSEC), from the fruit bodies of the edible mushroom Pleurotus florida, via alkaline extraction, followed by fractionation by freeze-thawing. Structural assignments were carried out using mono- and bi-dimensional nuclear magnetic resonance spectroscopy, monosaccharide composition, methylation analyses, and a controlled Smith degradation. It was a branched beta-glucan, with a main chain of (1-->3)-linked-Glcp residues, substituted at O-6 by single-unit Glcp side chains, on average to every fourth residue of the backbone.
Asunto(s)
Cuerpos Fructíferos de los Hongos/metabolismo , Pleurotus/metabolismo , beta-Glucanos/química , Secuencia de Carbohidratos , Espectroscopía de Resonancia Magnética , Datos de Secuencia Molecular , Estructura Molecular , beta-Glucanos/aislamiento & purificaciónRESUMEN
Indistinguishable partially 3-O-methylated galactans were isolated from the edible basidiomycetes Pleurotus eryngii and Pleurotus ostreatoroseus. They were obtained via successive aqueous extraction, freeze-thawing, precipitation with Fehling solution of soluble material, and ultrafiltration. Mono- and bidimensional 13C and 1H-nuclear magnetic resonance spectroscopy (HMBC, HETEROTOCSY, COSY, and HMQC), and methylation analysis were used to determine their structures. They were linear, partially 3-O-methylated, (1-->6)-linked alpha-d-galactans containing Gal and 3-Me-Gal, in a 3:1 molar ratio (GC-MS of alditol acetates).