Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
Más filtros










Intervalo de año de publicación
1.
Exp Parasitol ; 263-264: 108807, 2024 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-39043327

RESUMEN

African trypanosomiasis and malaria are among the most severe health challenges to humans and livestock in Africa and new drugs are needed. Leaves of Hyptis suaveolens Kuntze (Lamiaceae) and Momordica charantia L. (Cucurbitaceae) were extracted with hexane, ethyl acetate, and then methanol, and subjected to silica gel column chromatography. Structures of six isolated compounds were elucidated through NMR and HR-EIMS spectrometry. Callistrisic acid, dehydroabietinol, suaveolic acid, suaveolol, and a mixture of suaveolol and suaveolic acid (SSA) were obtained from H. suaveolens, while karavilagenin D and momordicin I acetate were obtained from M. charantia. The isolated biomolecules were tested against trypomastigotes of Trypanosoma brucei brucei and T. congolense, and against Plasmodium falciparum. The most promising EC50 values were obtained for the purified suaveolol fraction, at 2.71 ± 0.36 µg/mL, and SSA, exhibiting an EC50 of 1.56 ± 0.17 µg/mL against T. b. brucei trypomastigotes. Suaveolic acid had low activity against T. b. brucei but displayed moderate activity against T. congolense trypomastigotes at 11.1 ± 0.5 µg/mL. Suaveolol and SSA were also tested against T. evansi, T. equiperdum, Leishmania major and L. mexicana but the antileishmanial activity was low. Neither of the active compounds, nor the mixture of the two, displayed any cytotoxic effect on human foreskin fibroblast (HFF) cells at even the highest concentration tested, being 200 µg/mL. We conclude that suaveolol and its mixture possessed significant and selective trypanocidal activity.

2.
Molecules ; 28(2)2023 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-36677679

RESUMEN

Propolis is a resin that is gathered by bees from exudates produced by various plants. Its exact chemical composition depends on the plants available near the hive. Bees use propolis to coat the surfaces of the hive, where it acts as an anti-infective. Regardless of the chemical composition of propolis, it is always anti-protozoal, probably because protozoan parasites, particularly Lotmarium passim, are widespread in bee populations. The protozoa Trypanosoma brucei and T. congolense cause disease in humans and/or animals. The existing drugs for treating these diseases are old and resistance is an increasingly severe problem. The many types of propolis present a rich source of anti-trypanosomal compounds-from a material gathered by bees in an environmentally friendly way. In the current work, red Nigerian propolis from Rivers State, Nigeria was tested against T. brucei and T. congolense and found to be highly active (EC50 1.66 and 4.00 µg/mL, respectively). Four isoflavonoids, vestitol, neovestitol, 7-methylvestitol and medicarpin, were isolated from the propolis. The isolated compounds were also tested against T. brucei and T. congolense, and vestitol displayed the highest activity at 3.86 and 4.36 µg/mL, respectively. Activities against drug-resistant forms of T. brucei and T. congolense were similar to those against wild type.


Asunto(s)
Antiinfecciosos , Própolis , Trypanosoma brucei brucei , Trypanosoma congolense , Tripanosomiasis Africana , Humanos , Animales , Própolis/farmacología , Própolis/química , Nigeria , Tripanosomiasis Africana/tratamiento farmacológico
3.
Molecules ; 27(5)2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-35268726

RESUMEN

Profiling a propolis sample from Papua New Guinea (PNG) using high-resolution mass spectrometry indicated that it contained several triterpenoids. Further fractionation by column chromatography and medium-pressure liquid chromatography (MPLC) followed by nuclear magnetic resonance spectroscopy (NMR) identified 12 triterpenoids. Five of these were obtained pure and the others as mixtures of two or three compounds. The compounds identified were: mangiferonic acid, ambonic acid, isomangiferolic acid, ambolic acid, 27-hydroxyisomangiferolic acid, cycloartenol, cycloeucalenol, 24-methylenecycloartenol, 20-hydroxybetulin, betulin, betulinic acid and madecassic acid. The fractions from the propolis and the purified compounds were tested in vitro against Crithidia fasciculata, Trypanosoma congolense, drug-resistant Trypanosoma congolense, Trypanosoma b. brucei and multidrug-resistant Trypanosoma b. brucei (B48). They were also assayed for their toxicity against U947 cells. The compounds and fractions displayed moderate to high activity against parasitic protozoa but only low cytotoxicity against the mammalian cells. The most active isolated compound, 20-hydroxybetulin, was found to be trypanostatic when different concentrations were tested against T. b. brucei growth.


Asunto(s)
Própolis
4.
Nat Prod Res ; 36(19): 4943-4948, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34011227

RESUMEN

A new eusdesmane sesquiterpenoid, characterised as 5-acetoxy-9aß-hydroxy-4aαH-3,5α, 8aß-trimethyl-4, 4a, 6, 7, 8a, 9-hexahydronaphtho-([2, 3 b]-dihydrofuran-2-one)-8-one or phaeusmane F acetate (1) has been isolated from the rhizomes of the South African variety of wild ginger (iphonochilus aethiopicus (Schweinf) B.L. Burtt). The compound was obtained after a series of column and gel filtration chromatography. Its structure was elucidated by NMR and Mass-Spectrometric analyses, including 1 D-, 2 D-NMR and HR-LCMS. This is an initial report of the compound from a Siphonochilus sp. Previously isolated similar compounds from the plant material were 4aαH-3,5α,8aß-trimethyl-4,4a,8a,9-tetrahydronaphtho[2,3b]-furan-8-one (siphonochilone) (2), 9aß-hydroxy-4aαH-3,5α,8aß-trimethyl-4,4a,8a,9-tetrahydronaphtho-([2,3b]-dihydrofuran-2-one)-8-one (3), 4aαH-3,5α,8aß-trimethyl-4,4a,8a,9-tetrahydronaphtho-([2,3b]-dihydrofuran-2-one)-8-one (4), 2-hydroxy-4aαH-3,5α,8aß-trimethyl-4,4a,8a,9-tetrahydro-naphtho[2,3b]- furan-8(5H)-one (5), 4aαH-3,5α,8aß-trimethyl-4,4a,8a-trihydronaphtho-([2,3b]-dihydrofuran-2-one)-8-one (6).[Formula: see text].


Asunto(s)
Asarum , Sesquiterpenos , Zingiberaceae , Furanos/química , Furanos/farmacología , Sesquiterpenos/química , Sesquiterpenos/farmacología , Sudáfrica , Zingiberaceae/química
5.
Front Chem ; 9: 624741, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33968894

RESUMEN

The powdered roots of the medicinal plant Acacia nilotica were extracted with hexane and ethyl acetate, and the extracts were subjected to column chromatography for the isolation of potentially bioactive compounds and their screening against kinetoplastid pathogens. NMR and HREI mass spectrometric analyses identified two new diterpenes, characterized as 16, 19-dihydroxycassa-12-en-15-one (Sandynone, 1) and (5S, 7R, 8R, 9R, 10S, 13Z, 17S)-7,8:7,17:16,17-triepoxy-7,8-seco-cassa-13-ene (niloticane B, 2). The previously reported (5S,7R,8R,9R,10S) -(-)-7,8-seco-7, 8-oxacassa-13,15-diene-7,17-diol (3), (5S,7R,8R,9R,10S) -(-)-7,8-seco-7, 8-oxacassa-13,15-dien-7-ol-17-al (4), and (5S,7R,8R,9R,10S) -(-)-7,8-seco-7, 8-oxacassa-13,15-dien-7-ol (5) a, mixture of stigmasterol (6a) and sitosterol (6b), and lupeol (7) were also isolated. Several column fractions displayed significant activity against a panel of Trypanosoma and Leishmania spp., and from the most active fraction, compound 4 was isolated with high purity. The compound displayed high activity, particularly against T. brucei, T. evansi, and L. mexicana (0.88-11.7 µM) but only a modest effect against human embryonic kidney cells and no cross-resistance with the commonly used melaminophenyl arsenical and diamidine classes of trypanocides. The effect of compound 4 against L. mexicana promastigotes was irreversible after a 5-h exposure, leading to the sterilization of the culture between 24 and 48 h.

6.
Pathogens ; 10(2)2021 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-33562567

RESUMEN

Trypanosomiasis and leishmaniasis are a group of neglected parasitic diseases caused by several species of parasites belonging to the family Trypansomatida. The present study investigated the antitrypanosomal and antileishmanial activity of chalcones and flavanones from Polygonum salicifolium, which grows in the wetlands of Iraq. The phytochemical evaluation of the plant yielded two chalcones, 2',4'-dimethoxy-6'-hydroxychalcone and 2',5'-dimethoxy-4',6'-dihydroxychalcone, and two flavanones, 5,7-dimethoxyflavanone and 5,8-dimethoxy-7-hydroxyflavanone. The chalcones showed a good antitrypanosomal and antileishmanial activity while the flavanones were inactive. The EC50 values for 2',4'-dimethoxy-6'-hydroxychalcone against Trypanosoma brucei brucei (0.5 µg/mL), T. congolense (2.5 µg/mL), and Leishmania mexicana (5.2 µg/mL) indicated it was the most active of the compounds. None of the compounds displayed any toxicity against a human cell line, even at 100 µg/mL, or cross-resistance with first line clinical trypanocides, such as diamidines and melaminophenyl arsenicals. Taken together, our study provides significant data in relation to the activity of chalcones and flavanones from P. salicifolium against both parasites in vitro. Further future research is suggested in order to investigate the mode of action of the extracted chalcones against the parasites.

7.
Nat Prod Res ; 35(24): 5588-5595, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32713200

RESUMEN

The Nigerian and South African varieties of Siphonochilus aethiopicus were examined for their phytochemical constituents. The ethyl acetate extract of the rhizomes of the South African variety yielded a novel diarylheptanoid, 2,3-diacetoxy-7-(3'',4''-dihydroxy-5''-methoxyphenyl)-1-(4'-hydroxy-3'-methoxyphenyl)-5-heptene and the flavonoid 3,7-dimethoxyquercetin. From the hexane extract of the Nigerian variety, siphonochilone and another flavonoid, 3,4',7-trimethylkaempferol were isolated. The isolated compounds were characterised by NMR spectroscopic techniques and mass spectrometry. The diarylheptanoid was then assayed for antiplasmodial activity in vitro using a Plasmodium falciparum growth inhibition assay. At the concentrations tested, the compound inhibited parasite growth by 69 - 74%, without producing cytotoxic or significant haemolytic effects. The antiplasmodial activity of the compound is likely mediated by direct mechanism(s) in erythrocytic - stage parasites.


Asunto(s)
Antimaláricos , Zingiberaceae , Antimaláricos/farmacología , Diarilheptanoides , Extractos Vegetales/farmacología , Plasmodium falciparum
8.
Front Chem ; 8: 574103, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33282826

RESUMEN

Calliandra portoricensis is a medicinal plant growing freely in Nigeria. It is used traditionally to treat tuberculosis, as an anthelmintic and an abortifacient. Phytochemical fractionation and screening of its root extracts has yielded a novel (5-hydroxy-7-methoxy-4-oxo-1-chromanyl)-4-methoxy-p-benzoquinone (breverin)-substituted cassane diterpene, which was designated bokkosin. It was obtained from column chromatography of the ethyl acetate extract of the roots. The compound was characterized using IR, NMR (1D and 2D) and mass spectral data. Promising antiparasitic activity was observed against the kinetoplastid parasite Trypanosoma brucei brucei, as well as moderate activity against Trypanosoma congolense and Leishmania mexicana and low toxicity in mammalian cells, with the best in vitro EC50 values against T. b. brucei (0.69 µg/mL against a standard laboratory strain, and its multi-drug resistant clone (0.33 µg/mL). The effect on T. b. brucei in culture was rapid and dose-dependent, leading to apparently irreversible growth arrest and cell death after an exposure of just 2 h at 2 × or 4 × EC50. The identification of bokkosin constitutes the first isolation of this class of compound from any natural source and establishes the compound as a potential trypanocide that, considering its novelty, should now be tested for activity against other microorganisms as well.

9.
Int J Parasitol Drugs Drug Resist ; 14: 201-207, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33160277

RESUMEN

A bioassay-guided phytochemical investigation of propolis samples from Tanzania and Zambia that screened for activity against Trypanosoma brucei has led to the isolation of two novel flavanones with promising antitrypanosomal activity. The compounds were characterized based on their spectral and physical data and identified as 6-(1,1-dimethylallyl) pinocembrin and 5-hydroxy-4″,4″-dimethyl-5″-methyl-5″-H-dihydrofuranol [2″,3″,6,7] flavanone. The two compounds, together with the propolis extracts and fractions, were assayed against a standard drug-sensitive strain of T. b. brucei (s427 wild-type), multi-drug resistant-resistant T. b. brucei (B48), drug-sensitive T. congolense (1L300) and a derived diminazene-resistant T. congolense strain (6C3), and for toxicity against U947 human cells and RAW 246.7 murine cells. Activity against T. b. brucei was higher than against T. congolense. Interestingly, the Tanzanian propolis extract was found to be more active than its fractions and purified compounds in these assays, with an IC50 of 1.20 µg/mL against T. b. brucei. The results of a cytotoxicity assay showed that the propolis extracts were less toxic than the purified compounds with mean IC50 values > 165.0 µg/mL.


Asunto(s)
Antiprotozoarios , Própolis , Tripanocidas , Trypanosoma , Animales , Flavanonas , Humanos , Ratones , Trypanosoma brucei brucei
10.
Nanotechnology ; 31(19): 195101, 2020 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-31958777

RESUMEN

Natural products have been successfully used to treat various ailments since ancient times and currently several anticancer agents based on natural products are used as the main therapy to treat cancer patients, or as a complimentary treatment to chemotherapy or radiation. Balanocarpol, which is a promising natural product that has been isolated from Hopea dryobalanoides, has been studied as a potential anticancer agent but its application is limited due to its high toxicity, low water solubility, and poor bioavailability. Therefore, the aim of this study is to improve the characteristics of balanocarpol and increase its anticancer activity through its encapsulation in a bilayer structure of a lipid-based nanoparticle drug delivery system where the application of nanotechnology can help improve the limitations of balanocarpol. The compound was first extracted and isolated from H. dryobalanoides. Niosome nanoparticles composed of Span 80 (SP80) and cholesterol were formulated through an innovative microfluidic mixing method for the encapsulation and delivery of balanocarpol. The prepared particles were spherical, small, and uniform with an average particles size and polydispersity index ∼175 nm and 0.088, respectively. The encapsulation of balanocarpol into the SP80 niosomes resulted in an encapsulation efficiency of ∼40%. The niosomes formulation loaded with balanocarpol showed a superior anticancer effect over the free compound when tested in vitro on human ovarian carcinoma (A2780) and human breast carcinoma (ZR-75-1). This is the first study to report the use of SP80 niosomes for the successful encapsulation and delivery of balanocarpol into cancer cells.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Dipterocarpaceae/química , Neoplasias Ováricas/tratamiento farmacológico , Polifenoles/aislamiento & purificación , Polifenoles/farmacología , Cápsulas , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Colesterol/química , Femenino , Hexosas/química , Humanos , Liposomas , Extractos Vegetales/química , Polifenoles/química
11.
Molecules ; 24(6)2019 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-30884752

RESUMEN

Twelve propolis samples from different parts of Libya were investigated for their phytochemical constituents. Ethanol extracts of the samples and some purified compounds were tested against Trypanosoma brucei, Plasmodium falciparum and against two helminth species, Trichinella spiralis and Caenorhabditis elegans, showing various degrees of activity. Fourteen compounds were isolated from the propolis samples, including a novel compound Taxifolin-3-acetyl-4'-methyl ether (4), a flavanonol derivative. The crude extracts showed moderate activity against T. spiralis and C. elegans, while the purified compounds had low activity against P. falciparum. Anti-trypanosomal activity (EC50 = 0.7 µg/mL) was exhibited by a fraction containing a cardol identified as bilobol (10) and this fraction had no effect on Human Foreskin Fibroblasts (HFF), even at 2.0 mg/mL, thus demonstrating excellent selectivity. A metabolomics study was used to explore the mechanism of action of the fraction and it revealed significant disturbances in trypanosomal phospholipid metabolism, especially the formation of choline phospholipids. We conclude that a potent and highly selective new trypanocide may be present in the fraction.


Asunto(s)
Antiprotozoarios/química , Proliferación Celular/efectos de los fármacos , Própolis/química , Trypanosoma brucei brucei/efectos de los fármacos , Animales , Antiprotozoarios/farmacología , Caenorhabditis elegans/efectos de los fármacos , Caenorhabditis elegans/patogenicidad , Línea Celular , Fibroblastos/efectos de los fármacos , Humanos , Libia , Metabolómica , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/patogenicidad , Polifenoles/química , Polifenoles/farmacología , Própolis/farmacología , Trichinella spiralis/efectos de los fármacos , Trichinella spiralis/patogenicidad , Trypanosoma brucei brucei/patogenicidad
12.
Fitoterapia ; 134: 5-13, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30690125

RESUMEN

Hibiscus sabdariffa (Malvaceae) is a plant that is widely recognised for its antihypertensive properties; however the constituent(s) responsible for this biological activity are presently unknown. The aim of this study was to identify the potential compounds that are responsible for the vasorelaxant activity of H. sabdariffa. Thereafter, the mechanisms involved in producing the vasorelaxation were investigated. The plant was extracted consecutively with hexane, ethyl acetate and methanol. The methanolic extract was subjected to bioassay-guided fractionation in order to isolate pure compounds that possessed vasorelaxant activity. The vascular effects of the pure compounds were studied on the rat aorta in vitro using myography techniques. Hibiscus acid produced a concentration-dependent relaxation of the rat aorta pre-contracted with either phenylephrine (3 µM) or KCl (60 mM), irrespective of the presence of the endothelium. When the tissue was pre-contracted with phenylephrine, the concentration required to produce 50% relaxation (IC50), was 0.09 ±â€¯0.01 mg/ml. Hibiscus acid had no effect on the phasic contraction induced by phenylephrine in Ca2+-free physiological solution; but it did affect the component of the contraction that is due to Ca2+ influx. In parallel studies, garcinia acid, a diastereoisomer of hibiscus acid, was found to have an almost identical vasorelaxant effect. The vasorelaxant action of both compounds is most likely due to the inhibition of Ca2+ influx via voltage-dependent Ca2+ channels.


Asunto(s)
Aorta/efectos de los fármacos , Citratos/farmacología , Hibiscus/química , Vasodilatadores/farmacología , Animales , Calcio/análisis , Canales de Calcio Tipo L/fisiología , Femenino , Técnicas In Vitro , Masculino , Nigeria , Extractos Vegetales/farmacología , Ratas , Ratas Sprague-Dawley , Vasodilatación
13.
Artículo en Inglés | MEDLINE | ID: mdl-30685630

RESUMEN

The four components present in the trypanocidal treatment Samorin, the commercially available formulation of isometamidium, were separated and purified by column chromatography. These compounds as well as the Samorin mixture and the other phenanthridine trypanocide, homidium, were tested on Trypanosoma congolense and wild type, diamidine- and isometamidium-resistant Trypanosoma brucei brucei strains using an Alamar blue drug sensitivity assay. EC50 values obtained suggest that M&B4180A (2) was the most active of the components, followed by M&B38897 (1) in all the strains tested, whereas M&B4596 (4) was inactive. Samorin was found to be significantly more active than any of the individual components alone, against T. congolense and all three T. b, brucei strains. Samorin and all its active constituents displayed reduced activity against the previously characterised isometamidium-resistant strain ISMR1.


Asunto(s)
Resistencia a Medicamentos , Fenantridinas/análisis , Fenantridinas/farmacología , Tripanocidas/análisis , Tripanocidas/farmacología , Cromatografía , Trypanosoma brucei brucei/efectos de los fármacos , Trypanosoma congolense/efectos de los fármacos
14.
Sci Rep ; 8(1): 4613, 2018 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-29545637

RESUMEN

Natural products have made remarkable contributions to drug discovery and therapy. In this work we exploited various biochemical approaches to investigate the mode of action of 16-α-hydroxy-cleroda-3,13 (14)-Z-dien-15,16-olide (HDK-20), which we recently isolated from Polyalthia longifolia, on Trypanosoma brucei bloodstream trypomastigotes. HDK20 at concentrations ≥ EC50 (0.4 µg/ml) was trypanocidal, with its effect irreversible after only a brief exposure time (<1 h). Fluorescence microscopic assessment of DNA configuration revealed severe cell cycle defects after 8 h of incubation with the compound, the equivalent of a single generation time. This was accompanied by DNA fragmentation as shown by Terminal deoxynucleotidyl transferase dUTP Nick-End Labelling (TUNEL) assays. HDK-20 also induced a fast and profound depolarisation of the parasites' mitochondrial membrane potential and depleted intracellular ATP levels of T. brucei. Overall, HDK20 showed a multi-target mechanism of action, which provides a biochemical explanation for the promising anti-trypanosomatid activity in our previous report.


Asunto(s)
Diterpenos de Tipo Clerodano/farmacología , Extractos Vegetales/farmacología , Polyalthia/química , Tripanocidas/farmacología , Trypanosoma brucei brucei/efectos de los fármacos , Tripanosomiasis Africana/tratamiento farmacológico , Animales , Hojas de la Planta/química , Trypanosoma brucei brucei/crecimiento & desarrollo , Tripanosomiasis Africana/parasitología
15.
Acta Crystallogr E Crystallogr Commun ; 73(Pt 9): 1368-1371, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28932476

RESUMEN

The biologically active title compounds have been isolated from Hibiscus sabdariffa plants, hibiscus acid as a dimethyl sulfoxide monosolvate [systematic name: (2S,3R)-3-hy-droxy-5-oxo-2,3,4,5-tetra-hydro-furan-2,3-di-carb-oxy-lic acid dimethyl sulfoxide monosolvate], C6H6O7·C2H6OS, (I), and hibiscus acid dimethyl ester [systematic name: dimethyl (2S,3R)-3-hy-droxy-5-oxo-2,3,4,5-tetra-hydro-furan-2,3-di-carboxyl-ate], C8H10O7, (II). Compound (I) forms a layered structure with alternating layers of lactone and solvent mol-ecules, that include a two-dimensional hydrogen-bonding construct. Compound (II) has two crystallographically independent and conformationally similar mol-ecules per asymmetric unit and forms a one-dimensional hydrogen-bonding construct. The known absolute configuration for both compounds has been confirmed.

16.
J Med Chem ; 60(16): 7043-7066, 2017 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-28737909

RESUMEN

IKKß plays a central role in the canonical NF-kB pathway, which has been extensively characterized. The role of IKKα in the noncanonical NF-kB pathway, and indeed in the canonical pathway as a complex with IKKß, is less well understood. One major reason for this is the absence of chemical tools designed as selective inhibitors for IKKα over IKKß. Herein, we report for the first time a series of novel, potent, and selective inhibitors of IKKα. We demonstrate effective target engagement and selectivity with IKKα in U2OS cells through inhibition of IKKα-driven p100 phosphorylation in the noncanonical NF-kB pathway without affecting IKKß-dependent IKappa-Bα loss in the canonical pathway. These compounds represent the first chemical tools that can be used to further characterize the role of IKKα in cellular signaling, to dissect this from IKKß and to validate it in its own right as a target in inflammatory diseases.


Asunto(s)
Quinasa I-kappa B/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/farmacología , Pirroles/farmacología , Animales , Biomarcadores Farmacológicos/metabolismo , Línea Celular Tumoral , Diseño de Fármacos , Humanos , Quinasa I-kappa B/química , Ratones , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Subunidad p52 de NF-kappa B/metabolismo , Isoformas de Proteínas/antagonistas & inhibidores , Isoformas de Proteínas/química , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Pirimidinas/síntesis química , Pirimidinas/química , Pirroles/síntesis química , Pirroles/química , Transducción de Señal/efectos de los fármacos , Relación Estructura-Actividad
17.
Sci Rep ; 7(1): 923, 2017 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-28424496

RESUMEN

Profiling of extracts from twelve propolis samples collected from eight regions in Nigeria was carried out using high performance liquid chromatography (LC) coupled with evaporative light scattering (ELSD), ultraviolet detection (UV) and mass spectrometry (MS), gas chromatography mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). Principal component analysis (PCA) of the processed LC-MS data demonstrated the varying chemical composition of the samples. Most of the samples were active against Trypanosoma b. brucei with the highest activity being in the samples from Southern Nigeria. The more active samples were fractionated in order to isolate the component(s) responsible for their activity using medium pressure liquid chromatography (MPLC). Three xanthones, 1,3,7-trihydroxy-2,8-di-(3-methylbut-2-enyl)xanthone, 1,3,7-trihydroxy-4,8-di-(3-methylbut-2-enyl)xanthone a previously undescribed xanthone and three triterpenes: ambonic acid, mangiferonic acid and a mixture of α-amyrin with mangiferonic acid (1:3) were isolated and characterised by NMR and LC-MS. These compounds all displayed strong inhibitory activity against T.b. brucei but none of them had higher activity than the crude extracts. Partial least squares (PLS) modelling of the anti-trypanosomal activity of the sample extracts using the LC-MS data indicated that high activity in the extracts, as judged from LCMS2 data, could be correlated to denticulatain isomers in the extracts.


Asunto(s)
Antiprotozoarios/química , Própolis/química , Trypanosoma brucei brucei/efectos de los fármacos , Antiprotozoarios/farmacología , Cromatografía Líquida de Alta Presión/métodos , Cromatografía de Gases y Espectrometría de Masas , Análisis de los Mínimos Cuadrados , Espectroscopía de Resonancia Magnética , Estructura Molecular , Nigeria , Análisis de Componente Principal , Própolis/farmacología
18.
Nat Prod Res ; 30(16): 1880-4, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27498833

RESUMEN

This study reports the first phenolics from Wissadula genus (Malvaceae) and the anti-inflammatory activity of 7,4'-di-O-methylisoscutellarein. Using chromatographic methods, five phenolic compounds were isolated from aerial parts of Wissadula periplocifolia (L.) C. Presl. The compounds were identified as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, trans-cinnamic acid, tamgermanetin and 7,4'-di-O-methylisoscutellarein using spectroscopic methods. The flavone 7,4'-di-O-methylisoscutellarein showed anti-inflammatory activity by inhibiting neutrophils recruitment in a mice model of pleurisy and by decreasing significantly the production of cytokines IL-1ß and TNF-α.


Asunto(s)
Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/farmacología , Malvaceae/química , Animales , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos/métodos , Flavonas , Hidroxibenzoatos/farmacología , Masculino , Ratones Endogámicos C57BL , Estructura Molecular , Neutrófilos/efectos de los fármacos , Neutrófilos/patología , Parabenos/farmacología , Fenoles/química , Fenoles/farmacología , Componentes Aéreos de las Plantas/química , Pleuresia/tratamiento farmacológico , Pleuresia/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
19.
Phytochem Anal ; 27(3-4): 217-21, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27313159

RESUMEN

INTRODUCTION: Several taccalonolides with various bioactivities have been isolated from Tacca species but no studies to isolate taccalonolides with anti-trypanosomal activity from Tacca leontopetaloides have been reported. OBJECTIVES: To analyse extracts of the roots of Tacca leontopetaloides, purify the extracts by column chromatography and identify isolated compounds by spectroscopic methods. The compounds and fractions will be tested for antitrypanosomal activity in vitro against Trypanosoma brucei brucei. MATERIAL AND METHODS: Dried roots or tubers of Tacca leontopetaloides, chromatographic separation and spectroscopic identification. RESULTS: A novel taccalonolide A propanoate and some known taccalonolides were isolated and their structures were determined by NMR and mass spectrometry CONCLUSION: Several taccalonolides were isolated from Tacca leontopetaloides and were found to have in vitro antitrypanosomal activity against Trypanosoma brucei brucei and EC50 values for the isolated compounds were from 0.79 µg/mL. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Dioscoreaceae/química , Extractos Vegetales/farmacología , Esteroides/farmacología , Tripanocidas/farmacología , Trypanosoma brucei brucei/efectos de los fármacos , Espectrometría de Masas , Estructura Molecular , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Raíces de Plantas/química , Tubérculos de la Planta/química , Propionatos/química , Propionatos/aislamiento & purificación , Propionatos/farmacología , Esteroides/química , Esteroides/aislamiento & purificación , Tripanocidas/química , Tripanocidas/aislamiento & purificación
20.
Phytochem Anal ; 27(2): 107-15, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26662866

RESUMEN

INTRODUCTION: A previous study showed the unique character of Nigerian red propolis from Rivers State, Nigeria (RSN), with regards to chemical composition and activity against Trypanosoma brucei in comparison with other African propolis. OBJECTIVE: To carry out fractionation and biological testing of Nigerian propolis in order to isolate compounds with anti-trypanosomal activity. To compare the composition of the RSN propolis with the composition of Brazilian red propolis. METHODOLOGY: Profiling was carried out using HPLC-UV-ELSD and HPLC-Orbitrap-FTMS on extracts of two samples collected from RSN with data extraction using MZmine software. Isolation was carried out by normal phase and reversed phase MPLC. Elucidation of the compounds with a purity > 95% was performed by 1D/2D NMR HRMS and HRLC-MS(n) . RESULTS: Ten phenolic compounds were isolated or in the case of liquiritigenin partially purified. Data for nine of these correlated with literature reports of known compounds i.e. one isoflavanone, calycosin (1); two flavanones, liquiritigenin (2) and pinocembrin (5); an isoflavan, vestitol (3); a pterocarpan, medicarpin (4); two prenylflavanones, 8-prenylnaringenin (7) and 6-prenylnaringenin (8); and two geranyl flavonoids, propolin D (9) and macarangin (10). The tenth was elucidated as a previously undescribed dihydrobenzofuran (6). The isolated compounds were tested against Trypanosoma brucei and displayed moderate to high activity. Some of the compounds tested had similar activity against wild type T. brucei and two strains displaying pentamidine resistance. CONCLUSION: Nigerian propolis from RSN has some similarities with Brazilian red propolis. The propolis displayed anti-trypanosomal activity at a potentially useful level.


Asunto(s)
Própolis/farmacología , Trypanosoma brucei brucei/efectos de los fármacos , Animales , Antiprotozoarios/química , Antiprotozoarios/farmacología , Cromatografía Líquida de Alta Presión , Estructura Molecular , Própolis/química , Espectrofotometría Ultravioleta
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA