Rosario Rojas

Universidad Peruana Cayetano Heredia, Λίμα, Provincia de Lima, Peru

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Publications (36)55.94 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Ethnopharmacological relevance: A previous pilot ethnobotanical and ethnopharmacological study with the Q'echi' Maya identified the family Piperaceae, as an important taxonomic group traditionally used for the treatment of epileptic and culture-bound anxiety disorders and possessing activity in the GABA system. Following that lead, a botanical survey was conducted in Peru, where 47 species of Piperaceae were collected including 21 plants traditionally used for folk illnesses by the Yanesha of Peru, an indigenous Amazonian group.
    Journal of ethnopharmacology. 08/2014;
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    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.
    Phytochemistry Letters 02/2013; 6(1):128-134. · 1.18 Impact Factor
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    ABSTRACT: In order to assess the potential of six Peruvian plants for the development of phytocosmetics and/or nutraceuticals, the ascorbic acid content, flavonoids and total phenolic compounds, as well as antioxidant activities of hydroalcoholic extracts of Uncaria tomentosa (cat's claw), Zea mays (purple corn), Smallanthus sonchifolius (yacon), Lepidium meyenii (maca), Krameria triandra (ratania) and Physallis peruviana (aguaymanto) were evaluated. The in vitro antioxidant activities of these extracts were determined by means of DPPH, superoxide and hydroxyl radicals inhibition assays, as well as through the measurement of their reducing power and total antioxidant activity. Hydroalcoholic extracts of cat's claw and ratania showed the highest antioxidant activities, which may be due to their high content of ascorbic acid, flavonoids and total phenolics.
    Revista de la Sociedad Química del Perú. 01/2013; 79(1):13-20.
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    ABSTRACT: The larvae of the palm beetle Rhynchophorus palmarum L. (Coleoptera: Curculionidae) is known as "suri" in the Peruvian Amazon. The larvae, either raw or fried in its own oil, are an important food source for several groups of Amazon natives. The larvae are very appreciated by its taste and can be found in several local markets. On spite of its relevance on human food, little is known on the proximate composition of the palm beetle larvae consumed in Amazonian Peru. In the present article, we report the fatty acids profile from the oils separately obtained from the skin and digestive fat of the larvae as well as the proximate analysis of the skin and aminoacid profile of the insect protein. The high total protein content of the skin (45.82% on a dry weight basis), the oil content in the digestive fat and the aminoacid composition of the protein suggest that suri is a good source of nutrients, low usable responsible consumption.
    Revista de la Sociedad Química del Perú. 01/2013; 79(1):64-70.
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    ABSTRACT: We determined the proximate composition, amino acid profile, fatty acid profile and antinutrients contents (saponins and tannins) of seed and cakes (residues after oil extraction) of Plukenetia huayllabambana and Plukenetia volubilis. The seeds of P. huayllabambana, from the province of Mendoza Rodríguez, has higher oil content (54.3 versus 49.0%), while those from the province of San Martín (P. volubilis) showed higher protein content (29.6 versus 24.5%). Furthermore, protein content of P. volubilis´cake is greater than the one of P. huayllabambana (59 and 46%, respectively). The essential amino acid content of the seeds of both Plukenetia species is adequate, as recommended by the FAO/WHO, except for the amino acids lysine and leucine. In cakes, as well as seeds, the concentration of linoleic acid (omega-6) was larger in P. volubilis, while linolenic acid (omega-3) was found in greater proportion in P. huayllabambana.
    Revista de la Sociedad Química del Perú. 01/2013; 79(1):29-36.
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    ABSTRACT: Neglected diseases represent a major health problem. It is estimated that one third of the world population is infected with tuberculosis and additionally Leishmaniosis and Chagas disease affect approximately 30 million people. N-Acylhydrazone moiety is a repeated functional group present in several prototypes and drug candidates for these neglected diseases. On the other hand, furoxan system has been studied as pharmacophore for Leishmaniosis and Chagas diseases. Here we report on the design and preparation of forty hybrid furoxanyl N-acylhydrazones and on their activity on Mycobacterium tuberculosis, H37Rv and MDR strains, Trypanosoma cruzi, and Leishmania amazonensis. Among them, four derivatives displayed excellent to good selectivity indexes against the three different microorganisms. Hybrid compound N'-(4-phenyl-3-furoxanylmethylidene)isoniazide 9 showed the best antibacterial profile with MIC value 4.5 lesser than the value for the reference isoniazid against MDR strain. Furoxanyl N-acylhydrazone (E)-2-methyl-N'-(4-phenyl-3-furoxanylmethylidene)-4H-imidazo[1,2-a]pyridine-3-carbohydrazide 15 was ten-fold more potent against T. cruzi Amastigotes than the standard drug nifurtimox. On the other hand, derivatives (E)-N'-(5-benzofuroxanylmethylidene)benzo[d][1,3]dioxole-5-carbohydrazide 25 and (E)-N'-(4-hydroxy-3-methoxyphenylmethylidene)-3-methylfuroxan-4-carbohydrazide 37 emerged as leads for the development of new leishmanicidal agents. The adequate stability, in simulated biological system and plasma, and the lack of mutagenicity of these derivatives allow us to propose them as candidates for further pre-clinical studies.
    European Journal of Medicinal Chemistry 11/2012; 59C:64-74. · 3.43 Impact Factor
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    ABSTRACT: In order to explore the potential of tara (Caesalpinia spinosa) and camu camu (Myrciaria dubia) to develop natural sunscreen and anti-aging products, the present study evaluated their antioxidant, anti-elastase, anti-collagenase and photoprotective activities in vitro. The hydroalcoholic extract of tara showed good antioxidant activity in different in vitro assays (DPPH, TEAC, hydroxyl radical, superoxide radical), and it also inhibits collagenase enzyme better than the positive control epigallocatechin gallate (EC50 = 162.78 and 321.41 µg/ml, respectively). The hydroalcoholic extract of camu camu, despite its high content of ascorbic acid, did not show a significant antioxidant activity, but instead, in a culture of 3T3 fibroblasts it exerted at good protective effect in vitro (43.6%) against UV-B radiation. It is recommended to study the association of both extracts as a basis for developing an anti-aging product or a sunscreen with a dual mechanism of action.
    Revista de la Sociedad Química del Perú. 10/2012; 78(4):254-263.
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    ABSTRACT: Copitarsia corruda (Lepidoptera: Noctuidae) is a pest of asparagus, that causes serious economic losses to farmers. With the aim of controlling this insect by means of sex pheromones, the female sex glands volatiles were extracted with dichloromethane and analyzed by means of gas chromatography coupled to mass spectrometry. This same extract was then subjected to an analysis by gas chromatography coupled to Electroantennography to evaluate the response of the male antennas of C. corruda to the stimulus of the compounds contained in the extract. It was observed that male insects of respond positively to (Z)-9- tetradecenyl acetate. This compound appears to be the main sexual pheromone in the sex glands of female insects. These findings will be confirmed by field experiments.
    Revista de la Sociedad Química del Perú. 10/2012; 78(4):225-233.
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    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.
    Planta Medica 04/2012; 78(9):914-8. · 2.35 Impact Factor
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    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. tuberculosis.
    Boletín de la Sociedad Química del Péru 01/2012; 78(3):188-197.
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    Revista de Investigaciones Veterinarias del Perú. 12/2011; 23(2):160-170.
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    ABSTRACT: The study of traditional remedies used by the Chayahuita, an ethnic group from the Peruvian Amazonia, has prompted us to investigate in detail the ethanolic extract of Pseudelephantopus spicatus (Juss. ex Aubl.) C.F. Baker, which has demonstrated strong biological activity towards Leishmania amazonensis. Our goal was to discover the active compound of this plant-based remedy. A bioguided fractionation of the crude extract was undertaken based on the biological activity recorded against Leishmania amazonensis axenic amastigotes in in vitro bioassays. Three strongly to moderately active compounds were isolated: two hirsutinolides (the 8,13-diacetyl-piptocarphol and the 8-acetyl-13-O-ethyl-piptocarphol) and ursolic acid. IC(50) against Leishmania amazonensis axenic amastigotes are respectively 0.2, 0.37 and 0.99 μM (while IC(50) of amphotericin B is 0.41 μM). These compounds have never been isolated from this plant species, and germacranolides have never been identified as potential antileishmanial agents. The compounds isolated from Pseudelephantopus spicatus account for the antileishmanial activity of the plant, thus giving support to its use by the Chayahuita in Peru.
    Journal of ethnopharmacology 09/2011; 137(1):875-9. · 2.32 Impact Factor
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    ABSTRACT: The bioassay-guided purification of the ethanolic extract from the leaves of Piper hispidum led to the isolation of one new amide, N-2-(3',4',5'-trimethoxyphenyl)ethyl-2-hydroxybenzamide (1) as well as two known chalcones 2'-hydroxy-3',4',6'-trimethoxychalcone (2); 2',4'-dihydroxy-6'-methoxychalcone (cardamonin, 3) and one known flavanone, 5,7-dihydroxyflavanone (Pinocembrin, 4). Their structures were elucidated on the basis of spectroscopic data, including homo-and heteronuclear correlation NMR experiments (COSY, HSQC and HMBC) and comparison with data reported in the literature. The isolated compounds were tested against Leishmania amazonensis axenic amastigotes. The results showed that the known chalcone 2 exhibited the most potent antileishmanial activity with an IC(50) of 0.8 mu M (amphotericin B: IC(50) = 0.2 mu M) but was shown to exhibit mild cytotoxicity. (C) 2011 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.
    Phytochemistry Letters 09/2011; 4(3):363-366. · 1.18 Impact Factor
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    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
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    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 16-512 µg/mL against Cryptococcus neoformans, S. schenckii and several Candida species. All these results support the use of Psidium acutangulum in Peruvian traditional medicine. Its antifungal activity is due mainly to the 3'-formyl-2',4',6'-trihydroxydihydrochalcone.
    Revista de la Sociedad Química del Perú. 07/2011; 77(3):199-204.
  • Revista de la Sociedad Química del Perú. 04/2011; 77(2):135-143.
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    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.
    Bioorganic & medicinal chemistry 02/2011; 19(6):2023-9. · 2.82 Impact Factor
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    ABSTRACT: In the present study, we report four new dihydro-β-agarofuran sesquiterpenes (1-4), which were isolated from the leaves of Celastrus vulcanicola, in addition to five derivatives (5-9). Their stereostructures were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques, X-ray studies, chemical correlations and biogenetic means. Compounds 1-9 and the previously reported sesquiterpenes 10-25 have been tested as potential antimycobacterial agents against sensitive and resistant Mycobacterium tuberculosis strains. 1α-Acetoxy-6β,9β-dibenzoyloxy-dihydro-β-agarofuran (20) exhibited antituberculosis activity against the MDR TB strain with a MIC value of 6.2 μg/mL, comparable to or better than isoniazid or rifampin, two of the best first-line drugs commonly used in the treatment of TB. The structure-activity relationship is discussed.
    Bioorganic & medicinal chemistry 02/2011; 19(7):2182-9. · 2.82 Impact Factor
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    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
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    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.
    Chemistry & Biodiversity 04/2010; 7(4):922-32. · 1.81 Impact Factor

Publication Stats

274 Citations
55.94 Total Impact Points

Institutions

  • 2006–2014
    • Universidad Peruana Cayetano Heredia
      • Facultad de Ciencia y Filosofía
      Λίμα, Provincia de Lima, Peru
  • 2009
    • Université des Antilles et de la Guyane
      La Pointe à Pitre, Guadeloupe, Guadeloupe
  • 2008–2009
    • University of Louisville
      • Department of Chemistry
      Louisville, KY, United States
  • 2007
    • University of Toulouse
      Tolosa de Llenguadoc, Midi-Pyrénées, France
  • 2003–2005
    • Pontifical Catholic University of Peru
      Λίμα, Provincia de Lima, Peru