Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 4): o1015-6, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21754032

RESUMO

The title compound, 0.897C(30)H(48)O(3).0.103C(30)H(47)O(2)F is a co-crystal of two triterpenes isolated from the resin of Canarium schweinfurthiiand Engl. Both triterpenes consists of four trans-fused rings having chair/half-chair/half-chair and envelope conformations. The mol-ecular conformations are stabilized by intra-molecular C-H⋯O hydrogen bonds, forming rings of S(7) graph-set motif. In the crystal, mol-ecules are linked by inter-molecular O-H⋯O and C-H⋯O inter-actions, forming sheets parallel to (001). All atoms. excepting the axially-oriented hydroxyl group in the major component and the equatorially-oriented fluorine atom in the minor component, are overlapping.

2.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 4): o937-8, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21754206

RESUMO

The title compound, C(30)H(48)O(3), a triterpene isolated from the resin of canarium schweinfurthiiand, is an isomer of the previously reported triterpene 3α-hy-droxy-tirucalla-7,24-dien-21-oic acid [Mora et al. (2001 ▶). Acta Cryst. C57, 638-640], which crystallizes in the same trigonal space group. The title mol-ecule consists of four fused rings having chair, half-chair, half-chair and envelope conformations for rings A, B, C and D, respectively (steroid labelling). An intra-molecular C-H⋯O hydrogen bond generates an S(7) ring. In the crystal, mol-ecules are linked by O-H⋯O and C-H⋯O inter-actions, forming (001) sheets.

3.
J Ethnopharmacol ; 120(1): 17-24, 2008 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-18718518

RESUMO

The aim of this study was to evaluate the antimicrobial activity of the methanol extracts from Ficus chlamydocarpa (FCR), Ficus cordata (FCB), mixture of the two plants (FCM), as well as that of the isolated flavonoids Alpinumisoflavone (2), Genistein (3), Laburnetin (4), Luteolin (5) (isolated from FCR), Catechin (7) and Epiafzelechin (8) (isolated from FCB). Mycobacteria, fungi, Gram-positive and Gram-negative bacterial species were tested for their susceptibility to the above samples. The microplate dilution and radiometric respiratory methods were used to determine the susceptibility testing of the samples against Mycobacterium smegmatis and Mycobacterium tuberculosis, respectively. The disc diffusion assay was used to determine the sensitivity of the samples, whilst the micro-dilution method was used for the determination of the minimal inhibition concentration (MIC) and the minimal microbicidal concentration (MMC) against fungi, Gram-positive and Gram-negative bacterial species. All the samples except compound 7 were found to be active to Mycobacterium smegmatis and the MIC ranged from 0.61 to 312.50microg/ml. Compound 4 showed the best activity against Mycobacterium tuberculosis exhibiting an MIC of 4.88microg/ml. The results of the diffusion test indicated that the crude extract from FCB, FCM as well as compounds 5 and 8 were able to prevent the growth of all tested (fungi, Gram-positive and Gram-negative bacteria) organisms. The inhibition effect of the crude extract from Ficus chlamydocarpa was observed on 10 (62.5%) of the 16 tested microorganisms (excluding mycobacteria) whereas that of compounds 4, 2 and 3 was respectively noted on 14 (87.5%), 8 (50.0%) and 7 (39.9%) of the tested microbial species. FCB was found to be more active than FCR on most of the tested organisms. The results provided evidence that the studied plants extract, as well as some of the isolated compounds might be potential sources of new antimicrobial drug.


Assuntos
Anti-Infecciosos/farmacologia , Ficus/química , Flavonoides/farmacologia , Extratos Vegetais/farmacologia , Anti-Infecciosos/isolamento & purificação , Candida/efeitos dos fármacos , Flavonoides/isolamento & purificação , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Mycobacterium/efeitos dos fármacos
4.
Braz J Med Biol Res ; 38(7): 1087-94, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16007280

RESUMO

Dorstenia barteri and D. convexa extracts and some isolated components of the former were investigated for effectiveness against Trichomonas gallinarum and compared with quercetin and quercitrin. The antioxidant activity of the extracts/compounds was also determined. The minimum lethal concentrations (MLCs) for the extract of D. barteri leaves and twigs at 24 h were found to be 15.625 and 15.625 microg/ml, respectively. However, the MLCs of the leaf and twig extract of D. convexa were 125 and 437.5 microg/ml, respectively. The prenylated and geranylated chalcones were as active as the prenylated flavones, 6-prenylapigenin and the diprenylated derivative 6,8-diprenyleridictyol. The order of the antitrichomonal activity of the compounds at 24 h was: quercetin (0.121 microg/ml) > quercitrin (0.244 microg/ml) > or = bartericin B (0.244 microg/ml) > bartericin A (0.73 microg/ml) > stigmasterol (0.98 microg/ml) > 6,8-diprenyleridictyol = isobavachalcone = dorsmanin F (31.25 microg/ml). D. barteri extracts, quercitrin, and bartericin A, and the prenylated flavonoids had potent antioxidant properties. The twig extract of D. barteri was more potent than the leaf extract. Moderate (EC50 >50 microg/ml) and high (EC50 <50 microg/ml) antioxidant activities were detected in the leaf and twig extracts of D. barteri and the prenylated flavonoids. Prenylated flavonoids and the isolated compounds with antioxidant properties described here may account for the anti-inflammatory action of these extracts. The antitrichomonal and antioxidant activities shown by the extracts and compounds in this study are consistent with the ethnomedicinal and local use of the Dorstenia species studied.


Assuntos
Antioxidantes/farmacologia , Antitricômonas/farmacologia , Flavonoides/farmacologia , Moraceae/química , Trichomonas/efeitos dos fármacos , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antitricômonas/química , Antitricômonas/isolamento & purificação , Avaliação Pré-Clínica de Medicamentos , Flavonoides/química , Flavonoides/isolamento & purificação , Testes de Sensibilidade Parasitária , Extratos Vegetais/farmacologia , Quercetina/análogos & derivados , Quercetina/farmacologia
5.
Phytochemistry ; 55(8): 915-9, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11140524

RESUMO

Four new prenylated flavanones, dorsmanins 1, J and epi-dorsmanins F, G, identified, respectively, as 6,7-(2,2-dimethylpyrano)-8-prenyl-5,3',4'-trihydroxyflavanone, 6,7-(2,2-dimethyldihydropyrano)-8-prenyl-5,3',4'-trihydroxflavanone, and 2''-epimers of dorsmanins F and G were isolated from the aerial parts of Dorstenia mannii together with 13 known flavonoids: 4-hydroxylonchocarpin, 4-methoxylonchocarpin, 6-prenylchrysoeriol, 6,8-diprenyleriodictyol, gancaonin P and dorsmanins A-H. The structures of these secondary metabolites were determined by spectroscopic means and by comparison with published data and with authentic specimens for some of the known compounds.


Assuntos
Flavonoides/isolamento & purificação , Rosales/química , Flavonoides/química , Espectroscopia de Ressonância Magnética , Conformação Molecular , Prenilação de Proteína
6.
J Ethnopharmacol ; 87(1): 67-72, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12787956

RESUMO

The antioxidant activities of three prenylated flavonoids from Dorstenia mannii (6,8-diprenyleriodictyol, dorsmanin C and dorsmanin F) were compared to the common, non-prenylated flavonoid, quercetin. The prenylated flavonoids were found to be potent scavengers of the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH), and are more potent than butylated hydroxy toluene (BHT), a common antioxidant used as a food additive. The prenylated flavonoids also inhibited Cu(2+)-mediated oxidation of human low density lipoprotein (LDL). Dose-response studies indicated that the prenylated flavonoids were effective inhibitors of lipoprotein oxidation with IC50 values <1 microM and had similar inhibitory potency compared to quercetin, but was not directly related to Cu binding. Unlike quercetin, they did not show any pro-oxidant activity at high doses in the Cu(2+)-mediated lipoprotein oxidation system. The medicinal action of Dorstenia mannii may be related to the high concentration of potent antioxidant prenylated flavonoids in this species.


Assuntos
Antioxidantes/química , Flavonoides/química , Moraceae/química , África , Antioxidantes/isolamento & purificação , Compostos de Bifenilo , Hidroxitolueno Butilado/química , Flavonoides/isolamento & purificação , Sequestradores de Radicais Livres/química , Picratos/química , Quercetina/química , Fatores de Tempo
7.
J Ethnopharmacol ; 95(1): 7-12, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15374600

RESUMO

The present study was undertaken to investigate the antinociceptive and anti-inflammatory activities of the leaf and twig extracts of Dorstenia barteri (Moraceae) in mice. Both the leaf and twig extracts of Dorstenia barteri at 50, 100 and 200 mg/kg showed significant (P < 0.05-0.01) antinociceptive activities in chemical-, mechanical- and thermal-induced pain test models. Intraperitoneal administration of the plant extracts at 50, 100 and 200 mg/kg significantly (P < 0.05-0.01) inhibited carrageenin-induced acute inflammation in oedema paw weight, pulmonary oedema and number of pleural leucocytes in a dose-dependent way. The twig extract was found to be more active than the leaf extract in all the experimental models used. The inhibitory effects of the plant extracts were comparable to those of the reference drugs acetylsalicyclic acid (ASA) and phenylbutazone (PBZ) at 100 mg/kg i.p. The significant reduction in acetic acid-induced abdominal contractions, the decrease in oedema paw weight as well as in the number of leucocytes in the pleural cavity exudates, and the significant increase in the reaction time and pain threshold of mice observed in this study suggest that Dorstenia barteri extracts possess both anti-inflammatory and antinociceptive activities. The present study, therefore, lend pharmacological support to the folkloric uses of Dorstenia barteri extracts in the treatment, control and/or management of arthritis, rheumatism, gout, headache and other forms of body pains in some parts of Africa.


Assuntos
Analgésicos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Moraceae , Caules de Planta , Analgésicos/isolamento & purificação , Analgésicos/uso terapêutico , Animais , Anti-Inflamatórios não Esteroides/isolamento & purificação , Anti-Inflamatórios não Esteroides/uso terapêutico , Relação Dose-Resposta a Droga , Edema/tratamento farmacológico , Feminino , Masculino , Camundongos , Medição da Dor/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Folhas de Planta
8.
Int J Antimicrob Agents ; 37(2): 156-61, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21163632

RESUMO

The present study assessed the antimicrobial activities of various natural products belonging to the terpenoids, alkaloids and phenolics against a collection of Gram-negative multidrug-resistant (MDR) bacteria. The results demonstrated that most of the compounds were extruded by bacterial efflux pumps. In the presence of the efflux pump inhibitor phenylalanine arginine ß-naphthylamide (PAßN), the activities of laurentixanthone B (xanthone), plumbagin (naphthoquinone), 4-hydroxylonchocarpin (flavonoid) and MAB3 (coumarin) increased significantly against all studied MDR bacteria. Laurentixanthone B, 4-hydroxylonchocarpin and MAB3 contained the same pharmacophoric moiety as plumbagin. This study indicates that the AcrAB-TolC (Enterobacteriaceae) and MexAB-OprM (Pseudomonas aeruginosa) efflux pumps are involved in resistance of Gram-negative bacteria to most of the natural products.


Assuntos
Antibacterianos/farmacologia , Produtos Biológicos/farmacologia , Farmacorresistência Bacteriana Múltipla , Bactérias Gram-Negativas/efeitos dos fármacos , Alcaloides/metabolismo , Alcaloides/farmacologia , Antibacterianos/química , Antibacterianos/metabolismo , Produtos Biológicos/química , Transporte Biológico , Humanos , Proteínas de Membrana Transportadoras/metabolismo , Fenóis/metabolismo , Fenóis/farmacologia , Terpenos/metabolismo , Terpenos/farmacologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-22468007

RESUMO

Traditional medicine refers to health practices, approaches, knowledge and beliefs incorporating plant, animal and mineral based medicines, spiritual therapies, manual techniques and exercises, applied singularly or in combination to treat, diagnose and prevent illnesses or maintain well-being. In the last decade traditional medicine has become very popular in Cameroon, partly due to the long unsustainable economic situation in the country. The high cost of drugs and increase in drug resistance to common diseases like malaria, bacteria infections and other sexually transmitted diseases has caused the therapeutic approach to alternative traditional medicine as an option for concerted search for new chemical entities (NCE). The World Health Organisation (WHO) in collaboration with the Cameroon Government has put in place a strategic platform for the practice and development of TM in Cameroon. This platform aims at harmonizing the traditional medicine practice in the country, create a synergy between TM and modern medicine and to institutionalize a more harmonized integrated TM practices by the year 2012 in Cameroon. An overview of the practice of TM past, present and future perspectives that underpins the role in sustainable poverty alleviation has been discussed. This study gives an insight into the strategic plan and road map set up by the Government of Cameroon for the organisational framework and research platform for the practice and development of TM, and the global partnership involving the management of TM in the country.


Assuntos
Atenção à Saúde/organização & administração , Medicinas Tradicionais Africanas/estatística & dados numéricos , Medicinas Tradicionais Africanas/tendências , Plantas Medicinais , Camarões , Cultura , Previsões , Humanos , Programas Nacionais de Saúde/organização & administração , Pesquisa/tendências , Fatores Socioeconômicos
10.
Acta Trop ; 116(1): 100-4, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20599632

RESUMO

The aim of this study was to evaluate the antimycobacterial, antigonorrheal and reverse transcriptase activities of five flavonoids: isobachalcone (IBC); kanzanol C (KAN); 4-hydroxylonchocarpin (4-LCP); stipulin (SPL) and amentoflavone (AMF) from Dortenia barteri, together with the crude extract from this plant. The Agar disc diffusion, broth microdilution, microplate alamar blue assay (MABA), radiometric respiratory technique using BACTEC 460 system and the reverse transcriptase (RT) assay were used for the investigations. The results of the antimycobacterial assay showed that the crude extract and compounds were able to prevent the growth of Mycobacteria with MIC<10 microg/ml being recorded with IBC on M. tuberculosis. Results of the killing rate experiment revealed that total inhibition effect on M. tuberculosis H37Rv strain was noted with IBC and SPL at day 9 when tested at 4x MIC. The results of the antigonorrheal assay indicated that MIC values below 10 microg/ml were also recorded with IBC on all the tested N. gonorrhoeae strains, meanwhile good activities (MIC<10 microg/ml) were also noted with the extract, KAN, 4-LCP and SPL on some of these strains. The anti-reverse transcriptase activities of extract and compounds also demonstrated that all samples were able to inhibit at various extents the reverse transcriptase activity, with IBC and 4-LCP showing the best effects. The overall results of this work provided evidence that the crude extract as well as some flavonoids from D. barteri could be potential sources of new antimicrobial drug against tuberculosis (TB), gonorrhea and probably the acquired immunodeficiency syndrome.


Assuntos
Antibacterianos/farmacologia , Flavonoides/farmacologia , Moraceae/química , Fitoterapia , Extratos Vegetais/farmacologia , Inibidores da Transcriptase Reversa/farmacologia , Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Análise de Variância , Antibacterianos/química , Antibacterianos/uso terapêutico , Flavonoides/química , Flavonoides/uso terapêutico , Gonorreia/tratamento farmacológico , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium smegmatis/efeitos dos fármacos , Mycobacterium tuberculosis/efeitos dos fármacos , Neisseria gonorrhoeae/efeitos dos fármacos , Oxazinas , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Inibidores da Transcriptase Reversa/química , Inibidores da Transcriptase Reversa/uso terapêutico , Tuberculose/tratamento farmacológico , Xantenos
11.
J Ethnopharmacol ; 124(3): 551-5, 2009 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-19450674

RESUMO

AIM OF THE STUDY: This study was aimed at investigating the antimicrobial activity of the methanolic extract (MMB) and compounds isolated from the stem bark of Morus mesozygia, namely 3beta-acetoxyurs-12-en-11-one (1), moracin Q (2), moracin T (3), artocarpesin (4), cycloartocarpesin (5), moracin R (6), moracin U (8), moracin C (9), and moracin M (10). MATERIALS AND METHODS: The liquid microdilution assay was used in the determination of the minimal inhibitory concentration (MIC) and the minimal microbicidal concentration (MMC), against nine bacterial and two fungal species. RESULTS: The results of the MIC determination showed that the compounds 3, 4, 8 and 9 were able to prevent the growth of all tested microbial species. All other samples showed selective activities. Their inhibitory effects were noted on 90.9% studied organisms for the crude extract, 81.8% for compound 6, 72.7% for compound 10, 63.6% for compound 1, 54.5% for compound 5, and 45.5% for compound 2. The lowest MIC value of 39 microg/ml was obtained with the crude extract against Escherichia coli. The corresponding value for compounds (5 microg/ml) was registered with compound 9 on Shigella dysenteriae and compound 3 on E. coli, S. dysenteriae, Pseudomonas aeruginosa, Salmonella typhi and Bacillus cereus. The lowest MIC value (39 microg/ml) observed with the crude extract (on E. coli) was only eightfold greater than that of gentamycin used as reference antibiotic (RA) while the corresponding value (5 microg/ml) recorded with compounds 3 and 9 was equal to that of RA on the corresponding microorganisms. CONCLUSIONS: The obtained results highlighted the interesting antimicrobial potency of M. mesozygia as well as that of the studied compounds, and provided scientific basis for the traditional use of this species.


Assuntos
Anti-Infecciosos/farmacologia , Morus/química , Antibacterianos/química , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Meios de Cultura , Fungos/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Metanol/química , Testes de Sensibilidade Microbiana , Casca de Planta/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Caules de Planta/química , Solventes
12.
Afr J Tradit Complement Altern Med ; 4(3): 294-8, 2007 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-20161892

RESUMO

A new glyceryl derivative (Glyceryl-1-hexacosanoate) and a flavone derivative (methyletherapigenin) were isolated from the stem bark extract of Piptadenia africana, a western Cameroonian plant species. Common terpenes like sitosterol, beta-amyrin and eicosane were also isolated. These compounds were identified using physical and spectroscopic methods including mp, IR, (1)H and (13)C-NMR, DEPT, COSY, HMQC, HMBC, EI MS, HREI MS as well as some chemical transformations. The antibacterial activity of the extract, the fractions and the pure compounds is also discussed.

13.
Planta Med ; 50(3): 210-2, 1984 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17340299

RESUMO

Root bark extracts of ZANTHOXYLUM TESSMANNII (Engl.) Ayafor COMB. NOV. (Syn. FAGARA TESSMANNII Engl.) yielded, besides chelerythrine, dihydrochelerythrine, fagaramide and lupeol previously reported from this taxon, ten other compounds viz:nitidine, dihydronitidine, 9-methoxychelerthrine, gamma-fagarine, skimmianine, arctigenin methylether, savinin and a mixture of campesterol, beta-sitosterol and stigmasterol. The implications of the present results for the taxonomic position of ZANTHOXYLUM TESSMANNII is discussed.

14.
Braz. j. med. biol. res ; 38(7)July 2005. ilus
Artigo em Inglês | LILACS | ID: lil-403864

RESUMO

Dorstenia barteri and D. convexa extracts and some isolated components of the former were investigated for effectiveness against Trichomonas gallinarum and compared with quercetin and quercitrin. The antioxidant activity of the extracts/compounds was also determined. The minimum lethal concentrations (MLCs) for the extract of D. barteri leaves and twigs at 24 h were found to be 15.625 and 15.625 æg/ml, respectively. However, the MLCs of the leaf and twig extract of D. convexa were 125 and 437.5 æg/ml, respectively. The prenylated and geranylated chalcones were as active as the prenylated flavones, 6-prenylapigenin and the diprenylated derivative 6,8-diprenyleridictyol. The order of the antitrichomonal activity of the compounds at 24 h was: quercetin (0.121 æg/ml) > quercitrin (0.244 æg/ml) > or = bartericin B (0.244 æg/ml) > bartericin A (0.73 æg/ml) > stigmasterol (0.98 æg/ml) > 6,8-diprenyleridictyol = isobavachalcone = dorsmanin F (31.25 æg/ml). D. barteri extracts, quercitrin, and bartericin A, and the prenylated flavonoids had potent antioxidant properties. The twig extract of D. barteri was more potent than the leaf extract. Moderate (EC50 >50 æg/ml) and high (EC50 <50 æg/ml) antioxidant activities were detected in the leaf and twig extracts of D. barteri and the prenylated flavonoids. Prenylated flavonoids and the isolated compounds with antioxidant properties described here may account for the anti-inflammatory action of these extracts. The antitrichomonal and antioxidant activities shown by the extracts and compounds in this study are consistent with the ethnomedicinal and local use of the Dorstenia species studied.


Assuntos
Animais , Antioxidantes/farmacologia , Antitricômonas/farmacologia , Flavonoides/farmacologia , Moraceae/química , Trichomonas/efeitos dos fármacos , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antitricômonas/química , Antitricômonas/isolamento & purificação , Avaliação Pré-Clínica de Medicamentos , Flavonoides/química , Flavonoides/isolamento & purificação , Testes de Sensibilidade Parasitária , Extratos Vegetais/farmacologia , Quercetina/análogos & derivados , Quercetina/farmacologia
16.
Nat Prod Rep ; 11(1): 91-117, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15206458
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA