Ana R. Díaz-Marrero

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In a screening of Basidiomycete cultures isolated from marine invertebrates collected along the Chilean coastline for the production of antibiotics we identified a Penicillium brevicompactum strain as a producer of metabolites inhibiting the growth of bacteria and fungi. Bioactivity guided purification resulted in the isolation of four known metabolites.(More)
The electrophoretic behavior in polyacrylamide gels of the acidic polysaccharides produced by the soil bacteria Bradyrhizobium (Chamaecytisus) strain BGA1 and Bradyrhizobiumjaponicum USDA1 10 has been studied. Both polysaccharides were polydisperse, producing a ladder-like pattern after fixation with Alcian Blue and silver staining of the gel. The(More)
It is known that some strains of Vibrio parahaemolyticus are responsible for gastroenteric diseases caused by the ingestion of marine organisms contaminated with these bacterial strains. Organic products that show inhibitory activity on the growth of the pathogenic V. parahaemolyticus were extracted from a Vibrio native in the north of Chile. The inhibitory(More)
Bioassay-guided purification of an ethanolic extract of Cystoseira myrica against HEPG-2 (liver) and HCT116 (colon) human cancer cell lines led to the isolation of 3-keto-22-epi-28-nor-cathasterone, 1 and cholest-4-ene-3,6-dione, 2. This finding allowed us to report for the first time that a brassinosteroid-related metabolite occurs in seaweed. These(More)
In this work the antifeedant effects of the halogenated monoterpenes 1-13 were tested against several divergent insect species. These compounds have been isolated from Plocamium cartilagineum (6 was isolated as an acetyl derivative), except for 4, which was isolated from Pantoneura plocamioides. We have also included the semisynthetic derivatives 1a, 2a,(More)
Nine halogenated monoterpenes isolated from the red alga Plocamium cartilagineum have been evaluated for their cytotoxic effects on the tumor cell lines CT26 (murine colon adenocarcinoma), SW480 (human colon adenocarcinoma), HeLa (human cervical adenocarcinoma) and SkMel28 (human malignant melanoma) with several multidrug resistance mechanisms and the(More)
There is an urgency to find new treatments for the devastating epidemic of diabetes. Pancreatic β-cells viability and function are impaired in the two most common forms of diabetes, type 1 and type 2. Regeneration of pancreatic β-cells has been proposed as a potential therapy for diabetes. In a preliminary study, we screened a collection of marine products(More)
Diabetes is a consequence of a decrease on functional β-cell mass. We have recently demonstrated that epoxypukalide (Epoxy) is a natural compound with beneficial effects on primary cultures of rat islets. In this study, we extend our previous investigations to test the hypothesis that Epoxy protects β-cells and improves glucose metabolism in STZ-induced(More)
Two new steroids (1 and 2) and the known pregna-1,4,20-trien-3-one (3) have been isolated from the Pacific octocoral Carijoa multiflora. Compound 1 possesses a novel spiropregnane-based steroidal skeleton. The photochemical transformation of 3 into 1 allowed the assignment of the absolute configuration at C-10 of 1. The antibacterial activities of compounds(More)
Pronuciferine N-oxide (1), a proaporphine N-methyl-N-oxide alkaloid, along with the parent alkaloid pronuciferine (2) were isolated from Berberis coletioides. The structure of the new compound was determined by spectroscopic evidence. Compound 1 is the first naturally occurring proaporphinoid alkaloid with an N-oxide functionality.