[show abstract][hide abstract] ABSTRACT: Two new 13,28-epoxyoleanane triterpene saponins, magnosides A (1) and B (2), were isolated from the 95% ethanolic extract of Cybianthus magnus (Mez) Pipoly roots. Their structures were deduced by a combination of spectral analyses and chemical evidences as compared to data reported in the literature. The hemolytic activity of both compounds was measured. Compound 1 was shown to exhibit the strongest hemolytic activity with a HD50 of 3.8 μM followed by 2 with a HD50 of 33.5 μM. The bioactivity of compounds 1 and 2 was also evaluated in vitro against different cellular models including Mycobacterium tuberculosis, Leishmania amazonensis axenic amastigotes, mouse peritoneal macrophages and eight cancer cell lines. While neither of the tested compounds displayed any activity against M. tuberculosis, both exhibited anti-leishmanial activity against axenic amastigotes as well as in vitro growth inhibitory activity against all tested cancer cell lines with IC50 growth inhibitory concentrations ranging between 4 μM and 33 μM. The compounds displayed similar growth inhibitory activity in cancer cell lines sensitive to pro-apoptotic stimuli versus those displaying various levels of resistance to such stimuli. Quantitative videomicroscopy analyses revealed that compounds 1 and 2 are cytotoxic.
[show abstract][hide abstract] ABSTRACT: Two new dihydrochalcones (1, 2), as well as eight known compounds, piperaduncin C (3), 2',6'-dihydroxy-4'-methoxydihydrochalcone (4), 4,2',6'-trihydroxy-4'-methoxydihydrochalcone (5), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (6), 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (7), 4-hydroxy-3-(3-methyl-2-butenoyl)-5-(3-methyl-2-butenyl)-benzoic acid (8), 2,2-dimethyl-8-(3-methyl-2-butenyl)-2H-1-chromene-6-carboxylic acid (9), and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid (10) were isolated from the leaves of Piper dennisii Trelease (Piperaceae), using a bioassay-guided fractionation to determine their antileishmanial potential. Among them, compound 10 exhibited the best antileishmanial activity (IC50 = 20.8 µM) against axenic amastigote forms of Leishmania amazonensis, with low cytotoxicity on murine macrophages. In the intracellular macrophage-infected model, compound 10 proved to be more active (IC50 = 4.2 µM). The chemical structures of compounds 1-10 were established based on the analysis of the spectroscopic data.
[show abstract][hide abstract] ABSTRACT: Two known 13,28-epoxy-oleanane triterpene saponins (1) and (2), were isolated from the 95%
ethanolic extract of the roots of Myrsine coriaceae and Myrsine andina. Their structures were
deduced by combined spectral analysis and chemical evidences based on data reported in the
literature. Compounds 1 and 2 were evaluated in vitro against different cellular models such as
Mycobacterium tuberculosis, Leishmania amazonensis axenic amastigotes, six human cancer
cell lines (Hs683, T98G, U251, HT29, MCF7, SKMEL28) and two murine cell lines (CT26
and B16F10). Compound 1 was found to exhibit antileishmanial activity (IC = 16 μg/mL) 50
whereas compound 2 was inactive (IC > 50 μg/mL). Furthermore, compound 1 exhibited 50
stronger inhibition activity on human cancer cells (IC = 15 μg/mL) and on murine cell lines 50
(IC = 10 μg/mL) than compound 2 (IC > 82 and 42 μg/mL, respectively). As the only 50 50
difference between 1 and 2 is due to a substitution of an aldehyde group by a hydroxymethyl
moiety, these results showed the crucial role of the aldehyde function at C-30 for the
cytotoxicity. In contrast, none of the tested compounds revealed activity against M.
Boletín de la Sociedad Química del Péru 01/2012; 78(3):188-197.
[show abstract][hide abstract] ABSTRACT: RESUMEN En el presente trabajo se evaluó la actividad antifúngica de los extractos etanólicos de Thevetia peruviana (Pers.) K. Schum. (Apocynaceae), Spondias mombin L. (Anacardiaceae), Calycophyllum spruceanum (Benth.) Hook. f. ex K. Schum. (Rubiaceae) y Psidium acutangulum DC (Myrtaceae), cuatro plantas utilizadas en la medicina tradicional peruana contra las infecciones micóticas de la piel. El extracto etanólico de Psidium acutangulum fue el más activo contra los hongos evaluados (Candida albicans, Sporothrix schenckii y Trychophyton mentagrophytes), por lo que fue sometido a fraccionamiento biodirigido que condujo al aislamiento de 3'-formil-2',4',6'-trihidroxidihidrochalcona. Este compuesto mostró concentraciones inhibitorias mínimas en el rango de 16-512 µg/mL contra los hongos Cryptococcus neoformans, S. schenckii y varias especies de Candida. Los resultados obtenidos apoyan el uso de Psidium acutangulum en la medicina tradicional peruana. Su actividad antifúngica se debe principalmente a la 3'-formil-2',4',6'-trihidroxidihidrochalcona. ABSTRACT We report here the antifungal activities of the ethanolic extracts of Thevetia peruviana (Pers.) K. Schum. (Apocynaceae), Spondias mombin L. (Anacardiaceae), Calycophyllum spruceanum (Benth.) Hook. f. ex K. Schum. (Rubiaceae) and Psidium acutangulum DC (Myrtaceae), four plants used in peruvian traditional medicine against skin mycosis. The most active sample against the evaluated fungi (Candida albicans, Sporothrix schenckii and Trychophyton mentagrophytes) was the ethanol extract of Psidium acutangulum, which was submitted to bioassay-guided fractionation, leading to the isolation of 3'-formyl-2',4',6'-trihydroxydihydrochalcone. This compound showed minimum inhibitory concentrations of a b c
[show abstract][hide abstract] ABSTRACT: To determine the antimicrobial potential of marine actinomycetes against drug-resistant pathogens represented by strains of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE).
Strains of actinomycetes (29) isolated from marine sediment were evaluated by their characteristics in two culture media and by testing their inhibitory capacity by in vitro antagonism against multi-drug resistant (MDR) pathogenic bacteria for MRSA and VRE. Organic extracts of 3 selected actinomicetes were processed to determine the minimum inhibitory concentration (MIC) of the active compound.
Most isolated actinomycetes belong to a homogeneous group of write-gray actinomycetes with a good growth in Marine Agar. The inhibitory rates of the isolates were above 85% for both pathogens with inhibition zones greater than 69 and 78 mm in diameter for MRSA and VRE respectively. Dichloromethane extracts of 3 isolates (I-400A, B1-T61, M10-77) showed strong inhibitory activity of both pathogens, M10-77 being the highest actinomycete strain with antibiotic activity against methicillin-resistant S. aureus ATCC 43300 and vancomycin-resistant E. faecalis ATCC 51299 with a minimum inhibitory concentrations (MIC) of 7.9 and 31.7 μg/ml respectively. Phylogenetic analysis of M10-77 strain showed 99% similarity with the marine species Streptomyces erythrogriseus.
Marine sediments of the central coast of Peru, are a source of actinomycetes strains showing high capacity to produce bioactive compounds able to inhibit pathogens classified as multi-drug-resistant such as methicillin-resistant S. aureus and vancomycin-resistant E. faecalis.
Revista peruana de medicina experimental y salud publica 06/2011; 28(2):237-46.
[show abstract][hide abstract] ABSTRACT: A series of N'-substituted-2-(5-nitrofuran or 5-nitrothiophen-2-yl)-3H-benzo[d]imidazole-5-carbohydrazide derivatives were synthesized and investigated for their abilities to inhibit β-hematin formation, hemoglobin hydrolysis and in vivo for their antimalarial efficacy in rodent Plasmodium berghei. Selected analogues were screened for their antitubercular activity against sensitive MTB H(37)Rv and multidrug-resistant MDR-MTB strains, and cytotoxic activity against a panel of human tumor cell lines and two nontumourogenic cell lines. Compounds 3a, 5a, f, 6g were the most promising as inhibitors of β-hematin formation, however, their effect as inhibitors of hemoglobin hydrolysis were marginal. The most active compounds to emerge from the in vitro and in vivo murine studies were 3a and 6i, suggesting an antimalarial activity via inhibition of β-hematin formation and are as efficient as chloroquine. The cytotoxic and antitubercular activities of the present compounds were not comparable with those of the standard drugs employed. But, however, compound 5b showed better antitubercular activity compared to rifampin against multidrug-resistant MDR-MTB strains. Compounds 3a, 6i and 5b showed a good safety index.
[show abstract][hide abstract] ABSTRACT: Three new caffeic acid esters (1-3), four new lignans (4-7), and the known compounds (7'S)-parabenzlactone (8), dihydrocubebin (9), and justiflorinol (10) have been isolated from leaves of Piper sanguineispicum. Their structures were determined by spectroscopic methods, including 1D and 2D NMR, HRCIMS, CD experiments, and chemical methods. Compounds 1-10 were assessed for their antileishmanial potential against axenic amastigote forms of Leishmania amazonensis. Caffeic acid esters 1 and 3 exhibited the best antileishmanial activity (IC(50) 2.0 and 1.8 μM, respectively) with moderate cytotoxicity on murine macrophages.
Journal of Natural Products 10/2010; 73(11):1884-90. · 3.29 Impact Factor
[show abstract][hide abstract] ABSTRACT: The antimycobacterial activities of eight diterpenes, 1-8, isolated previously from Plectranthus and eleven esters, 9-19, of 7alpha-acetoxy-6beta,12-dihydroxyabieta-8,12-diene-11,14-dione (5) were evaluated against the MTB strains H(37)Rv and MDR. Only diterpenoids with a quinone framework revealed anti-MTB activity. Abietane 5 and its 6,12-dibenzoyl, 12-methoxybenzoyl, 12-chlorobenzoyl, and 12-nitrobenzoyl esters, 9, 11, 12, and 13, respectively, showed potent activities against the MDR strain with MIC values between 3.12 and 0.39 microg/ml. Cytotoxic activities towards 3T3 and Vero cells were also evaluated. Compound 11, with the best selectivity index, may be a suitable lead for further chemical modifications. The complete structural elucidation of the new esters, 9-14, 16, 18, and 19, as well as the NMR data of known derivatives 15 and 17 are reported.
[show abstract][hide abstract] ABSTRACT: A pharmacological screening of the ethanol extract and fractions of two Peruvian medicinal plants, Plagiochila disticha and Ambrosia peruviana, led to the isolation and characterization of three ENT-2,3-secoaromadendrane-type sesquiterpenoids, named plagiochiline A ( 1), I ( 2), and R ( 3), as well as of two pseudoguaianolids, damsin ( 4) and confertin ( 5), which exhibited significant cytotoxic activity against a panel of human tumor cell lines. Compounds 1, 4, and 5 were also investigated for their in vitro antileishmanial, trypanocidal, and antituberculosis activity against Leishmania amazonensis axenic amastigotes and Trypanosoma cruzi trypomastigotes, as well as against MDR and sensitive strains of Mycobacterium tuberculosis, respectively.
[show abstract][hide abstract] ABSTRACT: Ninety-four ethanolic extracts of plants used medicinally by the Yanesha, an Amazonian Peruvian ethnic group, for affections related to leishmaniasis and malaria were screened in vitro against Leishmania amazonensis amastigotes and against a Plasmodium falciparum chloroquine resistant strain.
The viability of Leishmania amazonensis amastigote stages was assessed by the reduction of tetrazolium salt (MTT) while the impact on Plasmodium falciparum was determined by measuring the incorporation of radio-labelled hypoxanthine.
Six plant species displayed good activity against Plasmodium falciparum chloroquine resistant strain (IC(50) < 10 microg/ml): a Monimiaceae, Siparuna aspera (Ruiz & Pavon), A. DC., two Zingiberaceae, Renealmia thyrsoidea (Ruiz & Pavon) Poepp. & Endl. and Renealmia alpinia (Rottb.), two Piperaceae (Piper aduncum L. and Piper sp.) and the leaves of Jacaranda copaia (Aubl.) D. Don (Bignoniaceae). Eight species displayed interesting leishmanicidal activities (IC50 < 10 microg/ml): Carica papaya L. (Caricaceae), Piper dennisii Trel (Piperaceae), Hedychium coronarium J. König (Zingiberaceae), Cestrum racemosum Ruiz & Pav. (Solanaceae), Renealmia alpinia (Rottb.) Zingiberaceae, Lantana sp. (Verbenaceae), Hyptis lacustris A. St.-Hil. ex Benth. (Lamiaceae) and Calea montana Klat. (Asteraceae). Most of them are used against skin affections by Yanesha people. Results are discussed herein, according to the traditional use of the plants and compared with data obtained from the literature.
Journal of ethnopharmacology 06/2009; 123(3):413-22. · 2.32 Impact Factor
[show abstract][hide abstract] ABSTRACT: A multidisciplinary and international team of scientists was assembled in the early 1990s to conduct an ethnobotanical study of plants used by the Aguaruna people of the Peruvian Amazon forest. The initial ethnobotanical project, carried out under the auspices of an International Cooperative Biodiversity Grant (ICBG), led to the collection of approximately 4000 plant species. Some members of the original team of scientists have continued this collaboration by focusing on potential sources of new anticancer, anti-infective, and wound-healing agents. This effort has uncovered several secondary metabolites representing a wide variety of chemical diversity. In this short review we describe some bioactive compounds of interest as part of our continuing collaboration.
Journal of Natural Products 03/2009; 72(3):524-6. · 3.29 Impact Factor
[show abstract][hide abstract] ABSTRACT: A pharmacological screening of the ethanol extract and fractions of Blepharodon nitidum led to the isolation of fourteen compounds, two of which, 24-hydroperoxycycloart-25-en-3beta-ol and 25-hydroperoxycycloart-23-en-3beta-ol, exhibited in vitro anti- Mycobacterium tuberculosis and antileishmanial activities, as well as significant cytotoxic activity against a panel of human tumor cell lines.
[show abstract][hide abstract] ABSTRACT: The antiproliferative bioassay-guided fractionation of five Peruvian plants, Doliocarpus dentatus, Picramnia sellowii, Strychnos mitscherlichii, Iryanthera juruensis, and Croton alnifolius, led to the isolation and identification of their different major cytotoxic constituents, betulinic acid (1), nataloe-emodin (2), bisnordihydrotoxyferine (4), 2',4'-dihydroxy-6'-methoxy-3,4-methylenedioxydihydrochalcone (5), and 2',4'-dihydroxy-4,6'-dimethoxydihydrochalcone (6) and 12-O-tetradecanoylphorbol-13-acetate (7), respectively. Eight human tumor cell lines and two nontumorigenic cell lines were used in this investigation. Their in vitro activity against Mycobacterium tuberculosis is also reported.
Journal of Natural Products 02/2008; 71(1):102-5. · 3.29 Impact Factor
[show abstract][hide abstract] ABSTRACT: Uncaria tomentosa, commonly known as cat's claw, is a medicinal plant native to Peru, which has been used for decades in the treatment of various inflammatory disorders. Uncaria tomentosa can be used as an antioxidant, has anti-apoptotic properties, and can enhance DNA repair, however it is best know for its anti-inflammatory properties. Treatment with Uncaria tomentosa extracts inhibits the production of the pro-inflammatory cytokine, TNF-alpha, which is a critical mediator of the immune response. In this paper, we showed that treatment of THP-1 monocyte-like cells with Uncaria tomentosa extracts inhibited the MAP kinase signaling pathway and altered cytokine expression. Using ELISA assays, we showed that treatment with Uncaria tomentosa extracts augmented LPS-dependent expression of IL-1beta by 2.4-fold, while inhibiting the LPS-dependent expression of TNF-alpha by 5.5-fold. We also showed that treatment of LPS-stimulated THP-1 cells with Uncaria tomentosa extracts blocked ERK1/2 and MEK1/2 phosphorylation in a dose-dependent manner. These data demonstrate that treatment of THP-1 cells with Uncaria tomentosa extracts has opposite effects on IL-1beta and TNF-alpha secretion, and that these changes may involve effects on the MAP kinase pathway.
Journal of Ethnopharmacology 02/2007; 109(2):312-7. · 2.76 Impact Factor
[show abstract][hide abstract] ABSTRACT: An ethanol extract of the Peruvian plant Clavija procera, a member of the rare Theophrastaceae family, was fractionated using a colorimetric bioassay-guided protocol against Mycobacterium tuberculosis (MTB), yielding the oleanane triterpenoid aegicerin (1) as the active constituent. Its MIC values ranged between 1.6 and 3.12 microg/mL against 37 different sensitive and resistant MTB strains (1 H37Rv, 21 susceptible clinical isolates, 2 INH-resistant clinical isolates, and 13 MDR clinical isolates).
Journal of Natural Products 06/2006; 69(5):845-6. · 3.29 Impact Factor
[show abstract][hide abstract] ABSTRACT: The 95% ethanol extract of the bark of Swartzia polyphylla DC (Fabaceae) possesses important larvicidal, antimycobacterial and antifungal activity in vitro. Bioassay-guided studies performed on the crude ethanol extract afforded T-cadinol as the larvicidal and anti-Mycobacterium tuberculosis principle, while the antifungal activity of the extract is due to the presence of the flavonoids biochanin A and dihydrobiochanin A.
CHEMICAL & PHARMACEUTICAL BULLETIN 03/2006; 54(2):278-9. · 1.56 Impact Factor
[show abstract][hide abstract] ABSTRACT: The antimicrobial and free radical scavenging activity of the ethanol extract and fractions of Gentianella nitida have been assessed. The most susceptible microorganisms were Candida albicans, Trichophyton mentagrophytes and Microsporum gypseum. The antifungal activity was concentrated in the 90% methanol and nonsoluble fractions, while the radical scavenging activity was stronger in the ethyl acetate and nonsoluble fractions.
[show abstract][hide abstract] ABSTRACT: The antimicrobial activity of 36 ethanol extracts from 24 plants, all of them currently used in the Peruvian traditional medicine for the treatment of several infectious and inflammatory disorders, was tested by means of the agar-well diffusion assay against four bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) and four fungi (Candida albicans, Trichophyton mentagrophytes, Microsporum gypseum and Sporothrix schenckii). Twenty-five (69%) extracts showed some degree of antimicrobial activity against at least one microorganism. The plants with the greatest antimicrobial activity were Cestrum auriculatum L. Heritier (Solanaceae), Iryanthera lancifolia Ducke Suesseng (Myristicaceae), Lepechinia meyenii (Walp.) Epling (Lamiaceae) and Ophryosporus peruvianus (Gmelin) King & H. Rob. (Asteraceae).
Journal of Ethnopharmacology 11/2003; 88(2-3):199-204. · 2.76 Impact Factor