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1.
Curr Med Chem ; 14(4): 417-30, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17305543

RESUMEN

Over the last decade, much research has focused on the potential health benefits of antioxidants and indeed many synthetic and natural compounds have been evaluated for their antioxidant profile. However, in several studies only a limited number of assays, often poorly validated, are used and the techniques available frequently lack specificity. These limitations may incorrectly influence the results. This review will therefore focus on several pitfalls that may emerge in vitro and in vivo antioxidant research. First, different in vitro techniques to determine antioxidant potential are discussed, including radical scavenging assays and fingerprinting methods. As a rule, a panel of different assays is indispensable to characterize and establish in vitro antioxidant activity. Furthermore, as problems of absorption, distribution, metabolism and excretion are only accounted for by in vivo studies, the need for in vivo antioxidant research is pointed out. Several methods to characterize the in vivo activity of antioxidants, including major drawbacks and pitfalls of some assays, have been discussed. The availability of both a representative "oxidative stress" animal model and a battery of well-validated assays to assess the broad diversity of oxidative damage and antioxidative defence parameters, are crucial for antioxidant research in vivo.


Asunto(s)
Antioxidantes/uso terapéutico , Investigación Biomédica , Evaluación Preclínica de Medicamentos/métodos , Animales , Antioxidantes/farmacocinética , Antioxidantes/farmacología , Humanos , Estrés Oxidativo/efectos de los fármacos
2.
J Ethnopharmacol ; 95(2-3): 399-404, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15507366

RESUMEN

The ethanolic extracts from fresh apical stems of Phyllanthus niruri L. (Euphorbiaceae) cultured on Murashige and Skoog (MS) medium supplemented with IBA/BAP/Coco nucifera L. milk for 1, 2, 4 and 6 months were phytochemically and biologically investigated and compared with intact plant part and whole plant extracts. Results from the in vitro antiplasmodial testing indicated that the EtOH extract of a 1-month-old callus culture (IC(50) = 16.3 +/- 2.5 microg/ml) exhibited a higher activity than the ethanolic extracts of the fresh apical stem (IC(50) = 18.2 +/- 2.4 microg/ml) and callus cultures of 2-, 4- and 6-months-old (25 microg/ml < IC(50) < 40 microg/ml). These activities were however lower than that displayed by the ethanolic extract of the whole plant (IC(50) < 3 microg/ml). The EtOH extract of 1-month-old callus culture (the most active) was fractionated with solvents of different polarities. Its CH(2)Cl(2) fraction rich in terpenic constituents (IC(50) = 9.2 +/- 3.4 microg/ml) exhibited a higher antiplasmodial activity than its isoamylic alcohol fraction obtained at pH 2-3 (IC(50) = 25.6 +/- 2.3 microg/ml) rich in flavonoids. The activity of these two fractions was lower than that displayed by the same fractions from the whole plant (2 microg/ml < IC(50) < 3 microg/ml). Alkaloidic fractions from the whole plant and 1-month-old callus culture of fresh apical stem were considered as inactive (IC(50) > 100 microg/ml).


Asunto(s)
Antimaláricos/farmacología , Phyllanthus , Plasmodium falciparum/efectos de los fármacos , Animales , Antimaláricos/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Tallos de la Planta , Plasmodium falciparum/fisiología
3.
J Ethnopharmacol ; 93(1): 27-32, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15182900

RESUMEN

The in vitro antiplasmodial activity of seven EtOH extracts and twenty fractions from the partition of the initial ethanolic extracts from seven African medicinal plants used in the Democratic Republic of Congo (DR Congo) for the treatment of malaria was evaluated. The most active EtOH extracts (IC50 < 3 microg/ml) were those from Cassia occidentalis leaves, Euphorbia hirta whole plant, Garcinia kola stem bark and Phyllanthus niruri whole plant. Their respective petroleum ether soluble fractions also exhibited an antiplasmodial activity with IC50 < 3 microg/ml. EtOH extracts from Vernonia amygdalina leaves (5 < IC50 < 10 microg/ml), Tetracera poggei leaves (10 < IC50 < 50 microg/ml) and Morinda morindoides leaves (50 < IC50 < 100 microg/ml) were less active, but their petroleum ether fractions exhibited a pronounced antiplasmodial activity (IC50 < 3 microg/ml). The same observation could also be made for the petroleum ether fraction from Cassia occidentalis, Euphorbia hirta, Garcinia kola and Phyllanthus niruri. Isoamyl alcohol fractions from Euphorbia hirta, Phyllanthus niruri and Vernonia amygdalina showed IC50) values less than 3 microg/ml, and from Cassia occidentalis, Garcinia kola, Morinda morindoides and Tetracera poggei between 10 and 50 microg/ml. The observed antiplasmodial activity may be related to the presence of terpenes, steroids, coumarins, flavonoids, phenolic acids, lignans, xanthones and anthraquinones.


Asunto(s)
Antimaláricos/farmacología , Plantas Medicinales , Plasmodium falciparum/efectos de los fármacos , Animales , Antimaláricos/aislamiento & purificación , República Democrática del Congo , Humanos , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Estructuras de las Plantas , Plasmodium falciparum/fisiología
4.
Phytomedicine ; 9(1): 56-61, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11924765

RESUMEN

Forty-two ethanolic extracts of thirty-six Rwandan medicinal plants were investigated for their influence on complement-mediated hemolysis. The plants were selected on the base of their ethnomedicinal use in infections and autoimmune diseases. Eight plant extracts showed an inhibitory activity against the classical pathway of the complement system and ten plant extracts against the alternative pathway. Three plant extracts exhibited an interesting activity against both pathways, i.e. Aspilia pluriseta, Coleus kilimandschari, and Macaranga kilimandscharica (leaves and stem). Further study indicated that the complement inhibitory activity was not caused by chelation of bivalent cations or by direct action on the target erythrocytes.


Asunto(s)
Activación de Complemento , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Medicina Tradicional Africana , Fitoterapia , Extractos Vegetales/farmacología , Humanos , Concentración 50 Inhibidora , Estructuras de las Plantas , Rwanda
5.
Phytomedicine ; 9(1): 62-8, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11924766

RESUMEN

Selected plants used in Rwandan traditional medicine for the treatment of infections and/or rheumatoid diseases were investigated for antiviral activity in vitro against human immunodeficiency virus type-1 (HIV-1). Of the 38 tested 80% ethanolic extracts, belonging to plants of 21 different families only the extracts from the leaves of Aspilia pluriseta (Asteraceae) and Rumex bequaertii (Polygonaceae) had interesting selectivity indices (SI = ratio of the 50% cytotoxic concentration to the 50% effective antiviral concentration) higher than 1. Further fractionation of the initially antivirally inactive ethanolic extract of Tithonia diversifolia, however, led to an aqueous fraction with a high anti-HIV-1 activity (SI > 461), indicating that the cytotoxicity of some plant components may mask the antiviral properties of the active plant substances in total plant extracts.


Asunto(s)
Fármacos Anti-VIH/farmacología , VIH-1/efectos de los fármacos , Medicina Tradicional Africana , Fitoterapia , Extractos Vegetales/farmacología , Fármacos Anti-VIH/uso terapéutico , Línea Celular/efectos de los fármacos , Infecciones por VIH/tratamiento farmacológico , Humanos , Extractos Vegetales/uso terapéutico , Estructuras de las Plantas , Rwanda
6.
J Ethnopharmacol ; 79(2): 155-63, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11801376

RESUMEN

A total of 45 Rwandan plant extracts, belonging to 37 different plant species out of 21 families, were investigated for their antibacterial, antifungal, and antiviral properties. The plants were selected on the base of their ethnomedicinal use against infections and autoimmune diseases. From all the plant extracts tested, only Clematis hirsuta (leaves) showed a pronounced antifungal activity against Candida albicans and the dermatophytes Trichophyton rubrum, Epidermophyton floccosum, and Microsporum canis. Seven plant extracts showed a high antiviral activity against the DNA-virus Herpes simplex type 1, while five and three plant extracts were highly active against the RNA-viruses Coxsackie and Polio, respectively. Only Macaranga kilimandscharica (leaves) showed an interesting anti-measles activity, whereas Eriosema montanum (leaves) and Entada abyssinica (leaves) were highly active against Semliki forest virus. Some plant extracts showed an antibacterial activity against Gram-positive bacteria and Mycobacterium fortuitum, but none of them were active against the Gram-negative bacteria tested.


Asunto(s)
Antiinfecciosos/farmacología , Antivirales/farmacología , Evaluación Preclínica de Medicamentos/métodos , Medicina Tradicional Africana , Extractos Vegetales/farmacología , Antibacterianos , Antiinfecciosos/uso terapéutico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Antivirales/uso terapéutico , Evaluación Preclínica de Medicamentos/estadística & datos numéricos , Fitoterapia/métodos , Fitoterapia/estadística & datos numéricos , Extractos Vegetales/uso terapéutico , Hojas de la Planta/química , Rwanda
7.
J Ethnopharmacol ; 79(2): 213-20, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11801384

RESUMEN

The chemical composition of essential oils from 15 aromatic medicinal plant species growing in the Democratic Republic of Congo have been studied. More than 15 constituents in an amount higher than 0.1% were identified in each essential oil. 1,8-cineole, alpha and beta-pinene, p-cymene, myrcene, gamma-terpinene, alpha-terpineol and limonene were prevalent constituents in almost more than 10 selected plant species. Results from the antibacterial testing by the diffusion method indicate that all essential oils (5 microl per disc) inhibited the growth of selected bacteria at different extents. The most active antibacterial essential oils were those of the leaves of Eucalyptus camadulensis and Eucalyptus terticornis (12-30 mm zone diameter of inhibition). They showed particularly a most potent inhibition of Pseudomonas aeruginosa growth (15-16 mm), followed by Eucalyptus robusta (12 mm). Essential oils from the leaves of Eucalyptus alba, Eucalyptus citriodora, Eucalyptus deglupta, Eucalyptus globulus, Eucalyptus saligna, Eucalyptus robusta, Aframomum stipulatum, Cymbopogon citratus, Ocimum americanum and that of the seeds of Monodora myristica showed also a good antibacterial activity (10-18 mm). Eucalyptus propinqua, Eucalyptus urophylla and Ocimum gratissimum essential oils were the less active samples against the selected bacteria. No correlation between the amount of major constituents such as 1,8-cineol, alpha-pinene, p-cymene, cryptone or thymol and the antibacterial activity was observed.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Medicina Tradicional Africana , Aceites Volátiles/química , Aceites Volátiles/farmacología , Antibacterianos/uso terapéutico , República Democrática del Congo , Evaluación Preclínica de Medicamentos/métodos , Evaluación Preclínica de Medicamentos/estadística & datos numéricos , Bacterias Gramnegativas/crecimiento & desarrollo , Bacterias Grampositivas/crecimiento & desarrollo , Aceites Volátiles/uso terapéutico , Fitoterapia/métodos , Fitoterapia/estadística & datos numéricos , Semillas/química
8.
Planta Med ; 67(6): 515-9, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11509970

RESUMEN

Thirty-five flavonoids of seven different types, namely isoflavonoids, chalcones, dihydroflavonols, flavanols, flavanones, flavones, and flavonols were investigated for their ability to inhibit ascorbate-induced microsomal lipid peroxidation and their cytotoxicity. For each activity a structure-activity relationship was established. Subsequently, an antioxidant selectivity index, i. e., the maximal non-toxic dose divided by the IC(50) value for lipid peroxidation, was introduced. Kaempferol showed the highest antioxidant selectivity index of all flavonoids tested.


Asunto(s)
Antioxidantes/farmacología , Flavonoides/toxicidad , Peroxidación de Lípido/efectos de los fármacos , Microsomas Hepáticos/efectos de los fármacos , Animales , Células Cultivadas , Fibroblastos/efectos de los fármacos , Flavonoides/antagonistas & inhibidores , Flavonoides/química , Flavonoides/farmacología , Humanos , Concentración 50 Inhibidora , Masculino , Ratas , Ratas Wistar , Piel/efectos de los fármacos , Relación Estructura-Actividad
9.
J Pharm Pharmacol ; 53(5): 757-61, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11370716

RESUMEN

Bridelia ferruginea Benth. (Euphorbiaceae) is a subtropical medicinal plant widely used in traditional African medicine against various diseases, including rheumatic pains. Seven of its constituents (3-O-methylquercetin (1), 3,7,3',4'-tetra-O-methylquercetin (rutisin, 2), myricetin (3), 3',4',5'-tri-O-methylmyricetin (ferrugin, 4), 3,3',4',5'-tetra-O-methylmyricetin (5), quercetin 3-O-glucoside (6), and a biflavanol gallocatechin-[4'-O-7]-epigallocatechin (7)) have been evaluated in-vitro in the xanthine-xanthine oxidase enzymatic system for inhibition of xanthine oxidase and radical scavenging activity. Results indicated that compounds 1, 3, 4 and 6 exhibited, at different levels, xanthine oxidase inhibiting and superoxide scavenging activity at micromolar concentrations, whereas compound 7 showed scavenging activity only. Compounds 2 and 5 were inactive in both cases. Study of the structure-activity relationship demonstrated that for flavonoids the xanthine oxidase inhibitory activity was reduced by methylation of the hydroxyl functionality at C-3 and in rings A and B. These results may partly explain and support the use of B. ferruginea stem bark for the treatment of rheumatic pains in traditional medicine.


Asunto(s)
Depuradores de Radicales Libres/farmacología , Fenoles/farmacología , Xantina Oxidasa/metabolismo , Artritis Reumatoide/tratamiento farmacológico , Humanos , Medicina Tradicional Africana , Fenoles/aislamiento & purificación , Extractos Vegetales , Plantas Medicinales , Xantina Oxidasa/efectos de los fármacos
10.
Ann Trop Med Parasitol ; 95(1): 47-57, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11235553

RESUMEN

The ethanolic, dichloromethane and lyophilized aqueous extracts of Cassia occidentalis root bark, Morinda morindoides leaves and whole plants of Phyllanthus niruri were evaluated for their antimalarial actvity in vivo, in 4-day, suppressive assays against Plasmodium berghei ANKA in mice. No toxic effect or mortality was observed in mice treated, orally, with any of the extracts as a single dose, of 500 mg/kg body weight, or as the same dose given twice weekly for 4 weeks (to give a total dose of 4 g/kg). No significant lesions were observed, by eye or during histopathological examinations, in the hearts, lungs, spleens, kidneys, livers, large intestines or brains of any mouse. At doses of 200 mg/kg, all the ethanolic and dichloromethane extracts produced significant chemosuppressions of parasitaemia (of > 60% for C. occidentalis root bark and Ph. niruri whole plant, and of 30% for M. morindoides leaves) when administered orally. The most active ethanolic extract, that of Ph. niruri, reduced parasitaemia by 73%. The dichloromethane extracts of M. morindoides and Ph. niruri produced similar reductions (74% and 72% chemosuppression, respectively), whereas that of C. occidentalis was slightly less active (60% chemosuppression). Each lyophilized aqueous extract was less active than the corresponding ethanolic extract.


Asunto(s)
Cassia/uso terapéutico , Euphorbiaceae/uso terapéutico , Malaria/tratamiento farmacológico , Fitoterapia , Plantas Medicinales , Plasmodium berghei/efectos de los fármacos , Rubiaceae/uso terapéutico , Administración Oral , Animales , Ratones , Extractos Vegetales/uso terapéutico , Hojas de la Planta , Raíces de Plantas , Resultado del Tratamiento
11.
Phytomedicine ; 7(1): 31-8, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10782488

RESUMEN

Three major extracts from some traditional preparations, based on medicinal plants, used as antidiarrhoeal agents were investigated for their putative antiamoebic and spasmolytic activities in vitro. Results indicated that both biological activities are concentrated in the polyphenolic fraction, and not in the saponin or alkaloid containing fractions. The most active polyphenolic extracts were those from Euphorbia hirta whole plant, leaves of Alchornea cordifolia, Crossopteryx febrifuga, Nauclea latifolia, Psidium guajava, Tithonia diversifolia, stem bark of Harungana madagascariensis, Mangifera indica, Maprounea africana and Psidium guajava, inhibiting Entamoeba histolytica growth with MAC < 10 micrograms/ml. The same extracts, at a concentration of 80 micrograms/ml in an organ bath, also exhibited more than 70% inhibition of acetylcholine and/or KCl solution-induced contractions on isolated guinea-pig ileum.


Asunto(s)
Amebicidas/farmacología , Antidiarreicos/farmacología , Medicina Tradicional Africana , Parasimpatolíticos/farmacología , Extractos Vegetales/farmacología , Plantas Medicinales , Animales , República Democrática del Congo , Entamoeba histolytica/efectos de los fármacos , Femenino , Cobayas , Íleon/efectos de los fármacos , Masculino , Pruebas de Sensibilidad Microbiana , Contracción Muscular/efectos de los fármacos
12.
Planta Med ; 66(1): 67-9, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10705738

RESUMEN

In addition to the known sterols and ketosteroids beta-sitosterol (24 alpha-ethylcholest-5-en-3 beta-ol), stigmasterol (24 alpha-ethylcholesta-5,22-dien-3 beta-ol), campesterol (24 alpha-methylcholest-5-en-3 beta-ol), beta-sitostenone (stigmast-4-en-3-one, 24 alpha-ethylcholest-4-en-3-one), stigmastenone (stigmasta-4,22-dien-3-one, 24 alpha-ethylcholesta-4,22-dien-3-one), campestenone (24 alpha-methylcholest-4-en-3-one), and stigmasta-3,5-dien-7-one (24 alpha-ethylcholesta-3,5-dien-7-one), the new steroids stigmasta-3,5,22-trien-7-one (24 alpha-ethylcholesta-3,5,22-trien-7-one), and campesta-3,5-dien-7-one (24 alpha-methylcholesta-3,5-dien-7-one) were isolated from the stem bark of Harrisonia abyssinica and identified by NMR and mass spectrometry.


Asunto(s)
Plantas Medicinales/química , Esteroides/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Estructura Molecular , Esteroides/química
13.
J Nat Prod ; 62(7): 954-8, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10425115

RESUMEN

A series of dimeric procyanidins (1-9) and some related polyphenols (10-15) were chosen as model compounds in a comparative investigation for various biological activities in order to obtain structure-activity relationships. Antiviral [herpes simplex virus (HSV) and human immunodeficiency virus (HIV)], antibacterial, superoxide radical-scavenging, and complement-modulating properties were assessed. In general, more pronounced activities were seen with epicatechin-containing dimers for anti-HSV, anti-HIV, and radical-scavenging effects, while the presence of ortho-trihydroxyl groups in the B-ring was important in compounds exhibiting anti-HSV and radical-scavenging effects and complement classical pathway inhibition. Double interflavan linkages gave rise to interesting antiviral effects (HSV and HIV) and complement inhibition. The influence of the degree of polymerization or the type of interflavan linkage (4-->6 or 4-->8) differed in the different biological systems evaluated. Only minor or moderate antibacterial effects were observed for the compounds under investigation.


Asunto(s)
Antocianinas/farmacología , Antiinfecciosos/farmacología , Antivirales/farmacología , Proteínas Inactivadoras de Complemento/farmacología , Flavonoides , Depuradores de Radicales Libres/farmacología , Fenoles/farmacología , Plantas Medicinales/química , Polímeros/farmacología , Antocianinas/química , Antocianinas/aislamiento & purificación , Antibacterianos , Fármacos Anti-VIH/farmacología , Bacterias/efectos de los fármacos , Euphorbiaceae/química , Hemólisis/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Perú , Simplexvirus/efectos de los fármacos
14.
Phytomedicine ; 6(1): 59-66, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10228613

RESUMEN

Forty six aqueous extracts from 38 medicinal plant species belonging to different families were selected on the basis of their traditional medicinal use as antidiarrhoeic agents. They were submitted in a broad biological screening including antibacterial, antiamoebic and antispasmodic activities. The results of the testing have indicated that 37 extracts (80.43%), 33 (71.74%) and 32 (69.54%) exhibited some level of antibacterial, antiamoebic and antispasmodic activity respectively. Only 8 plant extracts (17.39%) would act as antidiarrhoeic agents by a triple pronounced antibacterial, antiamoebic and antispasmodic action. They include aqueous extracts from Euphorbia hirta whole plant, leaves of Psidium guajava and Tithonia diversifolia, root bark of Alchornea cordifolia, Heinsia pulchella, Paropsia brazzeana, Rauwolfia obscura and Voacanga africana.


Asunto(s)
Antidiarreicos/aislamiento & purificación , Amebicidas/farmacología , Animales , Antibacterianos/farmacología , Antidiarreicos/farmacología , Bacterias/efectos de los fármacos , República Democrática del Congo , Entamoeba histolytica/efectos de los fármacos , Femenino , Cobayas , Íleon/efectos de los fármacos , Técnicas In Vitro , Masculino , Músculo Liso/efectos de los fármacos , Parasimpatolíticos/farmacología , Epidermis de la Planta/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Raíces de Plantas/química , Plantas Medicinales/química
15.
J Ethnopharmacol ; 68(1-3): 193-203, 1999 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-10624878

RESUMEN

Twenty extracts including ten EtOH and ten CH2Cl2 from different parts of nine African medicinal plants used in Congolese traditional medicine for the treatment of malaria, were submitted to a pharmacological test in order to evaluate their effect on P. falciparum growth in vitro. Of these plant species, 14 (70%) extracts including EtOH and CH2Cl2 from Cassia occidentalis leaves, Cryptolepis sanguinolenta root bark, Euphorbia hirta whole plant, Garcinia kola stem bark and seeds, Morinda lucida leaves and Phyllanthus niruri whole plant produced more than 60% inhibition of the parasite growth in vitro at a test concentration of 6 microg/ml. Extracts from E. hirta, C. sanguinolenta and M. morindoides showed a significant chemosuppression of parasitaemia in mice infected with P. berghei berghei at orally given doses of 100-400 mg/kg per day.


Asunto(s)
Antimaláricos/uso terapéutico , Malaria/tratamiento farmacológico , Extractos Vegetales/uso terapéutico , Plantas Medicinales/química , Plasmodium falciparum/efectos de los fármacos , Animales , República Democrática del Congo , Femenino , Humanos , Técnicas In Vitro , Masculino , Medicina Tradicional , Ratones , Solubilidad
16.
Phytochemistry ; 52(6): 1121-31, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10643673

RESUMEN

Ten new acylated triterpenoid saponins were isolated from the leaves of Maesa lanceolata. For their structure elucidation extensive use was made of homo- and heteronuclear 2D NMR techniques such as COSY, NOESY, HSQC and HMBC. All saponins identified contained the same tetraglycosidic side chain, but the triterpenoid moiety showed a variable esterification pattern. Monoester, diester and triester derivatives were present. Maesasaponin I was a 21-monoester derivative, i.e. ¿3 beta-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl- (1-->3)]-[beta-D-galactopyranosyl-(1-->2)]-beta-D-glucuronopyranosyl+ ++¿-21 beta-angeloyloxy-13 beta, 28-oxidoolean-16 alpha, 22 alpha, 28 alpha-triol. Maesasaponins III, IV3, V3 and VI2 had an additional acetyl, propanoyl, n-butanoyl and angeloyl substituent, respectively, in position 22. Maesasaponins II, IV2, V2, VI3 and VII1 were characterised as the 16-acetyl derivatives of maesasaponins I, III, IV3, V3 and VI2, respectively. Structures of saponins previously reported in M. lanceolata had to be revised.


Asunto(s)
Plantas Medicinales/química , Saponinas/química , Saponinas/aislamiento & purificación , Triterpenos/química , Triterpenos/aislamiento & purificación , Acetilación , Secuencia de Carbohidratos , Datos de Secuencia Molecular , Hojas de la Planta/química , Árboles/química
17.
Planta Med ; 65(3): 213-7, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17260306

RESUMEN

A bioassay-guided fractionation of an 80% acetone extract from BRIDELIA FERRUGINEA stem bark showing a dose-dependent inhibitory effect towards both the classical and the alternative pathways of the complement system resulted in the isolation of a biflavanol (gallocatechin-(4'- O-7)-epigallocatechin) ( 1), 3,5-dicaffeoylquinic acid ( 2), 1,3,4,5-tetracaffeoylquinic acid ( 3), and a series of 3-methoxyflavone derivatives, including quercetin 3-methyl ether ( 4), quercetin 3,7,3',4'-tetramethyl ether ( 5), myricetin 3',4',5'-trimethyl ether ( 6; new compound) named ferrugin, myricetin 3,3',4',5'-tetramethyl ether ( 7), myricetin ( 8), and quercetin 3- O-glucoside ( 9) as the active constituents. Especially the biflavanol 1 and the caffeoyl esters of quinic acid 2 and 3 showed a strong inhibitory effect (IC (50) < 10 microM) on the classical pathway, compared to rosmarinic acid. Also on the alternative pathway, the biflavanol 1, the quinic acid derivatives 2 and 3, and some of the 3-methoxyflavones 5, 7 and 8 were more active than rosmarinic acid. The quinic acid derivatives were shown to be inhibitors of the C1 component and the terminal route of the complement system.

18.
J Nat Prod ; 61(6): 757-61, 1998 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-9644059

RESUMEN

Four cucurbitacin glycosides were isolated from Picriafel-terrae and identified by MS and NMR spectroscopy as picfeltarraenin IA (1), picfeltarraenin IB (2), picfeltarraenin IV (4), and a new compound picfeltarraenin VI (3) (picfeltarraegenin I 3-O-beta-D-xylopyranoside). All four compounds acted as inhibitors on both the classical and alternative pathways of the complement system, with compound 3 exhibiting the highest inhibitory activity (IC50 29 +/- 2 microM and 21 +/- 1 microM, respectively). Compounds 1-4 showed no antiviral, antibacterial, or antifungal activities. Picfeltarraenin IA and IB were tested in an in vitro human tumor cell line panel, but displayed no cytotoxic activity.


Asunto(s)
Proteínas Inactivadoras de Complemento/aislamiento & purificación , Proteínas Inactivadoras de Complemento/farmacología , Glicósidos/aislamiento & purificación , Plantas Medicinales/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , China , Vía Alternativa del Complemento/efectos de los fármacos , Vía Clásica del Complemento/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Glicósidos/química , Glicósidos/farmacología , Humanos , Espectroscopía de Resonancia Magnética , Pruebas de Sensibilidad Microbiana , Espectrometría de Masa Bombardeada por Átomos Veloces , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Células Tumorales Cultivadas
19.
Planta Med ; 64(2): 97-109, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9525100

RESUMEN

Many compounds of plant origin have been identified that inhibit different stages in the replication cycle of human immunodeficiency virus (HIV): 1) virus adsorption: chromone alkaloids (schumannificine), isoquinoline alkaloids (michellamines), sulphated polysaccharides and polyphenolics, flavonoids, coumarins (glycocoumarin, licopyranocoumarin) phenolics (caffeic acid derivatives, galloyl acid derivatives, catechinic acid derivatives), tannins and triterpenes (glycyrrhizin and analogues, soyasaponin and analogues); 2) virus-cell fusion: lectins (mannose- and N-acetylglucosamine-specific) and triterpenes (betulinic acid and analogues); 3) reverse transcription; alkaloids (benzophenanthridines, protoberberines, isoquinolines, quinolines), coumarins (calanolides and analogues), flavonoids, phloroglucinols, lactones (protolichesterinic acid), tannins, iridoids (fulvoplumierin) and triterpenes; 4) integration: coumarins (3-substituted-4-hydroxycoumarins), depsidones, O-caffeoyl derivatives, lignans (arctigenin and analogues) and phenolics (curcumin); 5) translation: single chain ribosome inactivating proteins (SCRIP's); 6) proteolytic cleavage (protease inhibition): saponins (ursolic and maslinic acids), xanthones (mangostin and analogues) and coumarins; 7) glycosylation: alkaloids including indolizidines (castanospermine and analogues), piperidines (1-deoxynojirimicin and analogues) and pyrrolizidines (australine and analogues); 8) assembly/release: naphthodianthrones (hypericin and pseudohypericin), photosensitisers (terthiophenes and furoisocoumarins) and phospholipids. The target of action of several anti-HIV substances including alkaloids (O-demethyl-buchenavianine, papaverine), polysaccharides (acemannan), lignans (intheriotherins, schisantherin), phenolics (gossypol, lignins, catechol dimers such as peltatols, naphthoquinones such as conocurvone) and saponins (celasdin B, Gleditsia and Gymnocladus saponins), has not been elucidated or does not fit in the proposed scheme. Only a very few of these plant-derived anti-HIV products have been used in a limited number of patients suffering from AIDS viz. glycyrrhizin, papaverine, trichosanthin, castanospermine, N-butyl-1-deoxynojirimicin and acemannan.


Asunto(s)
Fármacos Anti-VIH/aislamiento & purificación , Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Plantas Medicinales , Alcaloides/aislamiento & purificación , Alcaloides/uso terapéutico , Fármacos Anti-VIH/farmacología , Cumarinas/aislamiento & purificación , Cumarinas/uso terapéutico , Flavonoides/aislamiento & purificación , Flavonoides/uso terapéutico , VIH/efectos de los fármacos , VIH/fisiología , Humanos , Lignanos/aislamiento & purificación , Lignanos/uso terapéutico
20.
Phytomedicine ; 5(2): 133-6, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23195766

RESUMEN

In addition to quercetin, hyperoside, rutin, vitexin, 2″-O-rhamnosylvitexin, (4″'-O-acetyl)-2″-O-rhamno-sylvitexin, epicatechin, procyanidin B-5, proanthocyanidin A-2, procyanidin B-2 and procyanidin C-1, which were reported before in Crataegus sinaica (Rosaceae), three more flavonoids were isolated from the same plant, i.e. (+)-taxifolin, 3-O-ß-arabinopyranosyl-(+)-taxifolin and 3-0-ß-xylopyranosyl-(+)-taxifolin. The in vitro anti-HIV activity of some selected flavonoids and proanthocyanidins was evaluated. The dimeric procyanidin B2 and proanthocyanidin A2, and especially the trimeric procyanidin C1 showed some in vitro anti-HIV activity.

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