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    Publicación
    DOI 10.1080/14786419.2021.1946534
    Synthesis, characterisation, crystal structure and antimicrobial evaluation of novel 6-alkoxyergosta-4,6,8(14),22-tetraen-3-one derived from natural ergosta-5,7,22-trien-3β-ol
    2023-01-02
    Bacho, Mitchell
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    Artigas, Vania
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    Araya-Contreras, Tiare
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    Bittner, Mauricio
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    Escobar, Carlos A.
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    Fuentealba, Mauricio
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    Becerra, Jose
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    In this study, we report a facile transformation starting from 5 alpha-hydroxyergosta-7,22-dien-3,6-dione (1) to afford two novel compounds: 6-methoxyergosta-4,6,8(14),22-tetraen-3-one (2) and 6-ethoxyergosta-4,6,8(14),22-tetraen-3-one (3) using alcoholic acid catalysis. Their structures were elucidated using NMR experiments, FT-IR, MS and X-ray analysis. These compounds were evaluated for antibacterial activity using the disk and broth diffusion test. In those tests, compound 3 was found to be the most significant antibacterial agent. In general, compounds 1-3 showed inhibition zone in the range of 7.00-12.3 mm for S. aureus and S. mutans, meanwhile for Gram-negative bacteria E. coli and Pseudomonas sp. was found to be in the range of 7.00-8.00 mm. For the most active, compound 3, MIC was significantly lower than that reported for ergosterol, in a value of 160 mu g/mL. Overall, these compounds were more active than their natural precursor.
  • Some of the metrics are blocked by your 
    Publicación
    DOI 10.1080/14786419.2021.1946534
    Synthesis, characterisation, crystal structure and antimicrobial evaluation of novel 6-alkoxyergosta-4,6,8(14),22-tetraen-3-one derived from natural ergosta-5,7,22-trien-3β-ol
    2023-01-02
    Bacho, Mitchell
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    Artigas, Vania
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    Araya-Contreras, Tiare
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    Bittner, Mauricio
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    Escobar, Carlos A.
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    Fuentealba, Mauricio
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    Becerra, Jose
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    ;
    In this study, we report a facile transformation starting from 5 alpha-hydroxyergosta-7,22-dien-3,6-dione (1) to afford two novel compounds: 6-methoxyergosta-4,6,8(14),22-tetraen-3-one (2) and 6-ethoxyergosta-4,6,8(14),22-tetraen-3-one (3) using alcoholic acid catalysis. Their structures were elucidated using NMR experiments, FT-IR, MS and X-ray analysis. These compounds were evaluated for antibacterial activity using the disk and broth diffusion test. In those tests, compound 3 was found to be the most significant antibacterial agent. In general, compounds 1-3 showed inhibition zone in the range of 7.00-12.3 mm for S. aureus and S. mutans, meanwhile for Gram-negative bacteria E. coli and Pseudomonas sp. was found to be in the range of 7.00-8.00 mm. For the most active, compound 3, MIC was significantly lower than that reported for ergosterol, in a value of 160 mu g/mL. Overall, these compounds were more active than their natural precursor.
    ScopusĀ© Citations 2  2
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    Publicación
    DOI 10.4067/s0717-97072022000405737
    PHYTOCHEMICAL STUDY ON ECTOMYCORRHIZAL FUNGI Cortinarius Magellanicus: AN UNUSUAL BROMINATED SECONDARY METABOLITE ISOLATED
    2022-11-01
    Bacho, Mitchell
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    Cajas, Daniel
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    Becerra, JosƩ
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    Phytochemical analysis of the basidiomycete Cortinarius magellanicus (family Cortinariaceae) resulted in the isolation of eight secondary metabolites, where a brominated secondary metabolite was isolated for first time from a natural source. The structure elucidation of this compound was made using one- and two-dimensional NMR experiments, FT-IR, GC-MS, HRESIMS and chemical derivation. The disk diffusion assay of the brominated compound 4 and 8 revealed a low inhibition on Gram-positive and Gram-negative bacteria, respectively. No antifungal activities were detected for these compounds.
  • Some of the metrics are blocked by your 
    Publicación
    DOI 10.4067/s0717-97072022000405737
    PHYTOCHEMICAL STUDY ON ECTOMYCORRHIZAL FUNGI Cortinarius Magellanicus: AN UNUSUAL BROMINATED SECONDARY METABOLITE ISOLATED
    2022-11-01
    Bacho, Mitchell
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    Cajas, Daniel
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    Becerra, JosƩ
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    ;
    Phytochemical analysis of the basidiomycete Cortinarius magellanicus (family Cortinariaceae) resulted in the isolation of eight secondary metabolites, where a brominated secondary metabolite was isolated for first time from a natural source. The structure elucidation of this compound was made using one- and two-dimensional NMR experiments, FT-IR, GC-MS, HRESIMS and chemical derivation. The disk diffusion assay of the brominated compound 4 and 8 revealed a low inhibition on Gram-positive and Gram-negative bacteria, respectively. No antifungal activities were detected for these compounds.
    ScopusĀ© Citations 1  1
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    Publicación
    DOI 10.1016/j.bmc.2018.11.030
    Antileishmanial activity and cytotoxicity of ent-beyerene diterpenoids
    2019-01-01
    Murillo, Jilmar A.
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    Gil, Juan F.
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    Upegui, Yulieth A.
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    Restrepo, Adriana M.
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    Robledo, Sara M.
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    Quinones, Winston
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    Echeverri, Fernando
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    Olivo, Horacio F.
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    Escobar, Gustavo
    We describe the in vitro activity of two natural isomeric ent-beyerene diterpenes, several derivatives and synthetic intermediates. Beyerenols 1 and 2 showed EC50 of 4.6 +/- 9.4 and 5.3 +/- 9.4 mu g/mL against amastigotes of L. (V) brazilensis, with SI of 5.1 and 7.7, respectively. Beyerenol 1 was synthesized from stevioside. In vivo experiments with bereyenols showed cure in 50% of hamsters infected with L. (V) brazilensis topically applied as Cream I (beyerenol 1, 0.81%, w/w) and Cream III (beyerenol 2, 1.96%, w/w). These results suggest that beyerenols are potential candidates for cutaneous leishmaniasis chemotherapy by topical application. In vitro assays of amastigotes of L. (V) brazilensis showed EC50 of 1.1 +/- 0.1 and 1.3 +/- 0.04 mu g/mL, with SI of 3.1 and 3.5 for hydrazone intermediates 10 and 11, respectively.
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    Publicación
    DOI 10.1016/j.bmc.2018.11.030
    Antileishmanial activity and cytotoxicity of ent-beyerene diterpenoids
    2019-01-01
    Murillo, Jilmar A.
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    Gil, Juan F.
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    Upegui, Yulieth A.
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    Restrepo, Adriana M.
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    Robledo, Sara M.
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    Quinones, Winston
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    Echeverri, Fernando
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    Olivo, Horacio F.
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    Escobar, Gustavo
    We describe the in vitro activity of two natural isomeric ent-beyerene diterpenes, several derivatives and synthetic intermediates. Beyerenols 1 and 2 showed EC50 of 4.6 +/- 9.4 and 5.3 +/- 9.4 mu g/mL against amastigotes of L. (V) brazilensis, with SI of 5.1 and 7.7, respectively. Beyerenol 1 was synthesized from stevioside. In vivo experiments with bereyenols showed cure in 50% of hamsters infected with L. (V) brazilensis topically applied as Cream I (beyerenol 1, 0.81%, w/w) and Cream III (beyerenol 2, 1.96%, w/w). These results suggest that beyerenols are potential candidates for cutaneous leishmaniasis chemotherapy by topical application. In vitro assays of amastigotes of L. (V) brazilensis showed EC50 of 1.1 +/- 0.1 and 1.3 +/- 0.04 mu g/mL, with SI of 3.1 and 3.5 for hydrazone intermediates 10 and 11, respectively.
    ScopusĀ© Citations 26  2
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    Publicación
    DOI 10.4067/s0717-97072018000404200
    ANTIMICROBIAL ACTIVITIES OF DITERPENOWS AND SEMISYNTHETIC DERIVATIVES FROM AZORELLA COMPACTA
    2018-12
    The antibacterial activity of two natural diterpenoids isolated from Azorella compacta together with six semisynthetic derivatives, were evaluated against three bacteria: Staphylococcus aureus. Escherichia coli and Mycobacterium smegmatis. The synthesis of the semisynthetic derivatives 3-5 and 8 have not been previously reported with the methods described in this research. The structures of all diterpenoids were elucidated by NMR H-1,C- 13 and IR spectroscopy. The natural diterpenoids, mulinolic acid (1) and azorellanol (2) did not present antibacterial activity, but the six derivatives: 12-oxo-11,13-alpha,alpha-dihydroxymulin-20-oic acid (3), 11-oxo-12,13-alpha,alpha-dihydroxymulin-20-oic acid (4) 11,12-dioxo-13-alpha-hydroxymulin-20-oic acid (5). 7-acetoxymulin-9,12-diene (6). mulin-9,12-dien-7-ol (7) and 7-acetoxy-12,13-dihydroxymulin-9-en (8) were active against three tested bacteria. The antibacterial activity reported for six semisynthetic diterpenoids may not be comparable with positive control ampicillin but demonstrate the possibility of modification of the biological activity of diterpenoids.
    ScopusĀ© Citations 5  1
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    Publicación
    DOI 10.4067/s0717-97072018000304082
    A NOVEL NORMULINANE ISOLATED FROM Azorella compacta AND ASSESSMENT OF ITS ANTIBACTERIAL ACTIVITY
    2018
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    Bacho, M.
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    Núñez, S.
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    Rovirosa, J.
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    Soler, A.
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    Blanc, V.
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    León, R.
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    Olea, A. F.
    ABSTRACT Phytochemical analysis of Azorella compacta resulted in the isolation of six known diterpenes and one unknown norditerpene using chromatographic methods. The structure of this new compound was established by spectroscopic analysis. The bioactivity of the new compound was assessed against six oral bacteria using a drop test method. A high level of growth inhibition was observed against F. nucleatum and P. gingivalis; however, other species such as V. parvula and A. actinomycetemcomitans were not affected.
    ScopusĀ© Citations 7  1
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    Publicación
    DOI 10.3390/md21020098
    Natural Products from Chilean and Antarctic Marine Fungi and Their Biomedical Relevance
    2023-2
    Arrieche, Dioni
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    Cabrera-Pardo, Jaime R.
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    Carrasco, Hector
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    Taborga, Lautaro
    Fungi are a prolific source of bioactive molecules. During the past few decades, many bioactive natural products have been isolated from marine fungi. Chile is a country with 6435 Km of coastline along the Pacific Ocean and houses a unique fungal biodiversity. This review summarizes the field of fungal natural products isolated from Antarctic and Chilean marine environments and their biological activities.
    ScopusĀ© Citations 11  2
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    Publicación
    DOI 10.3390/md20050337
    Secondary Metabolites Isolated from Chilean Marine Algae: A Review
    2022-5
    Arrieche, Dioni
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    Carrasco, Hector
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    Olea, Andres F.
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    Espinoza, Luis
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    Taborga, Lautaro
    Chile is in the extreme southwestern part of America, and it has an extreme length, of approximately 4300 km that increases to 8000 km considering the Chilean Antarctic Territory. Despite the large extent of its coastal territory and the diversity of geographic environments and climates associated with Chilean coasts, the research on marine resources in Chile has been rather scarce. From marine organisms found in Chilean coastal waters, algae have been the most studied, since they contain a wide range of interesting secondary metabolites that have some structural traits that make them unique and uncharacteristic. Thus, a wide structural variety of natural products including terpenoids (monoterpenes, sesquiterpenes, diterpenes, and meroterpenoids), furanones, and C-15-acetogenins have been isolated and identified. This review describes the existing literature on bioprospecting and exploration of secondary metabolites from Chilean coasts.
    ScopusĀ© Citations 8  2