Publications by authors named "Dionisio Olmedo"

Natural product (NP) databases are crucial tools in computer-aided drug design (CADD). Over the past decade, there has been a worldwide effort to assemble information regarding natural products (NPs) isolated and characterized in certain geographical regions. In 2023, it was published LANaPDB, and to our knowledge, this is the first attempt to gather and standardize all the NP databases of Latin America.

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Compound databases of natural products play a crucial role in drug discovery and development projects and have implications in other areas, such as food chemical research, ecology and metabolomics. Recently, we put together the first version of the Latin American Natural Product database (LANaPDB) as a collective effort of researchers from six countries to ensemble a public and representative library of natural products in a geographical region with a large biodiversity. The present work aims to conduct a comparative and extensive profiling of the natural product-likeness of an updated version of LANaPDB and the individual ten compound databases that form part of LANaPDB.

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Amphibians are widely known as a prolific source of bioactive metabolites. In this work, we isolated and characterized compounds with antiparasitic activity from the oocytes of the toad collected in Panama. Bio-guided isolation and structural elucidation were carried out using chromatographic and spectroscopic techniques, respectively.

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The number of databases of natural products (NPs) has increased substantially. Latin America is extraordinarily rich in biodiversity, enabling the identification of novel NPs, which has encouraged both the development of databases and the implementation of those that are being created or are under development. In a collective effort from several Latin American countries, herein we introduce the first version of the Latin American Natural Products Database (LANaPDB), a public compound collection that gathers the chemical information of NPs contained in diverse databases from this geographical region.

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Chemical libraries and compound data sets are among the main inputs to start the drug discovery process at universities, research institutes, and the pharmaceutical industry. The approach used in the design of compound libraries, the chemical information they possess, and the representation of structures, play a fundamental role in the development of studies: chemoinformatics, food informatics, pharmacokinetics, computational toxicology, bioinformatics, and molecular modeling to generate computational hits that will continue the optimization process of drug candidates. The prospects for growth in drug discovery and development processes in chemical, biotechnological, and pharmaceutical companies began a few years ago by integrating computational tools with artificial intelligence methodologies.

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Background: The microplate benchtop brine shrimp test (BST) has been widely used for screening and bio-guided isolation of many active compounds, including natural products. Although the interpretation given to the results appears dissimilar, our findings suggest a correlation between positive results with a specific mechanism of action.

Objective: This study aimed to evaluate drugs belonging to fifteen pharmacological categories having diverse mechanisms of action and carry out a bibliometric analysis of over 700 citations related to microwell BST.

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In this study, we evaluated 3444 Latin American natural products using cheminformatic tools. We also characterized 196 compounds for the first time from the flora of El Salvador that were compared with the databases of secondary metabolites from Brazil, Mexico, and Panama, and 42 969 compounds (natural, semi-synthetic, synthetic) from different regions of the world. The overall analysis was performed using drug-likeness properties, molecular fingerprints of different designs, two parameters similarity, molecular scaffolds, and molecular complexity metrics.

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In this work, we discuss the characterization and diversity analysis of 354 natural products (NPs) from Panama, systematically analyzed for the first time. The in-house database was compared to NPs from Brazil, compounds from Traditional Chinese Medicine, natural and semisynthetic collections used in high-throughput screening, and compounds from ChEMBL. An analysis of the "global diversity" was conducted using molecular properties of pharmaceutical interest, three molecular fingerprints of different design, molecular scaffolds, and molecular complexity.

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Twenty-eight neoflavonoids have been prepared and evaluated in vitro against HIV-1. Antiviral activity was assessed on MT-2 cells infected with viral clones carrying the luciferase reporter gene. Inhibition of HIV transcription and Tat function were tested on cells stably transfected with the HIV-LTR and Tat protein.

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In the course of our search for antineoplasic agents from Panamanian Flora, two new alkylresorcinols: 1-(2,6-dihydroxyphenyl)octan-l-one (1) and (+)-1-(3-(1-(2,6-dihydroxyphenyl)butyl)-2,6-dihydroxyphenyl)octan-l-one (2), together with three known compounds, (1R, 2R)-l-(benzo[d][1,3]dioxol-5-yl)propane-1,2,3-triol (3), (+)-aptosimon (4) and (-)-sesamin (5), were identified from the leaves of Homalomena wendlandii Schott (Araceae). Their structures were established by 1D and 2D NMR and IR spectroscopic, and MS methods. Compound 2 exhibited IC50 values of 3.

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We have synthesized fourteen 3-phenylcoumarin derivatives and evaluated their anti-HIV activity. Antiviral activity was assessed on MT-2 cells infected with viral clones carrying the luciferase gene as reporter. Inhibition of HIV transcription and Tat function were tested on cells stably transfected with the HIV-LTR and Tat protein.

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Ethnopharmacological Relevance: Cecropia obtusifolia (Cecropiaceae) and Psychotria poeppigiana (Synonym: Cephaelis elata, Rubiaceae) are two Latin American plants broadly used in traditional Amerindian medicine. The former, together with many other species of the genus Cecropia, share the folk reputation of curing heart failure, cough, asthma and bronchitis. The latter is used in Panama by Kuna and Ngäbe Buglé (Guaymies) native Indians for the treatment of dyspnea.

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The composition and biological activity of the essential oils from leaves, fruits, stems and bark of Protium confusum are reported for the first time. Forty-six to sixty-three constituents were identified ranging from 73.8% to 98.

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Ethnopharmacological Relevance: Dimerocostus strobilaceus is used by the Kuna Indians of Panama for the treatment of hypertension and other cardiovascular diseases.

Aim Of The Study: We investigated the vascular effects of acid and neutral fractions obtained from methanol and dichloromethane extracts of Dimerocostus strobilaceus.

Materials And Methods: The acid and neutral methanol fractions (A-MeOH and N-MeOH) or acid and neutral dichlorometanic fractions (A-DCM and N-DCM) were tested using isolated rat aortic rings with or without endothelium pre-contracted by phenylephrine.

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Bioassay-guided fractionation of the dichloromethane extract of the leaves of Marila pluricostata led to the isolation of 2alpha,3beta-dihydroxy-D:A-friedoolean-28-oic acid (pluricostatic acid), a new friedelane triterpenoid, (1), ten known triterpenoids and three sterols. Their chemical structures were elucidated through spectroscopic analysis. The less polar fractions, on GC/MS analysis and comparison with a MS library, resulted in the identification of twenty four sesquiterpenoids.

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Bioassay-guided fractionation of the chloroform and ethanol extracts of Tovomita longifolia leaves using cytotoxic and antimicrobial assays resulted in the isolation of four new benzophenones, (E)-3-(2-hydroxy-7-methyl-3-methyleneoct-6-enyl)-2,4,6-trihydroxybenzophenone (1), (E)-3-(6-hydroxy-3,7-dimethylocta-2,7-dienyl)-2,4,6-trihydroxybenzophenone (2), 8-benzoyl-2-(4-methylpenten-3-yl)chromane-3,5,7-triol (3), and 5-benzoyl-1,1,4a-trimethyl-2,3,4,4a,9,9a-hexahydro-1H-xanthene-6,8-diol (4), and two known benzophenones, 4-geranyloxy-2,6-dihydroxybenzophenone (5) and 3-geranyl-2,4,6-trihydroxybenzophenone (6). The structures of 1-4 were established by spectroscopic means and by molecular modeling calculations. Compounds 1 and 3-5 demonstrated cytotoxic activities against breast (MCF-7), central nervous system (SF-268), and lung (H-460) human cancer cell lines, while compounds 3-6 showed antimicrobial activity against Klebsiella pneumoniae, Mycobacterium smegmatis, Pseudomonas aeruginosa, Salmonella gallinarum, and Staphylococcus aureus.

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We have evaluated the anti-HIV activity of eleven natural 4-phenylcoumarins isolated from Marila pluricostata and three of their derivatives. Antiviral activity was assessed on MT-2 cells infected with viral clones carrying the luciferase gene as reporter. Inhibitions of HIV transcription and Tat function were tested on cells stably transfected with the HIV-LTR and Tat protein.

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Bioassay-guided fractionation of the CH(2)Cl(2) extract of the leaves of Marila pluricostata led to the isolation of 17 naturally occurring 4-phenylcoumarins, three of them, 5-hydroxy-8,8-dimethyl-4-phenyl-9,10-dihydro-8H-pyrano-[2,3-f]chromen-2-one (1), 5-hydroxy-8,8-dimethyl-4-phenyl-6-propionyl-9,10-dihydro-8H-pyrano-[2,3-f]chromen-2-one (2), and 5,7-dihydroxy-8-(3-methylbut-2-enyl)-4-phenylchromen-2-one (3), are new natural compounds; the remaining (4-17) are known mammea-type coumarins. Their structures were established by spectroscopic means. All compounds were tested in cytotoxicity assays against the MCF-7, H-460, and SF-268 human cancer cell lines.

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A new lignan, 3,4,5'-trimethoxy-3',4'-methylenedioxy-7,9':7',9 diepoxylignan (1) (6-[4-(3,4-dimethoxy-phenyl)-tetrahydro-furo[3,4-c.]furan-1-yl]-4-methoxy-benzo[ ] dioxole) together with two known lignans, 7'-epi.-sesartemin (2) and diayangambin (3), and a known flavonoid, 5-hydroxy-7,4'-dimethoxyflavone (4), were isolated from the leaves of Piper fimbriulatum.

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In this study, the furofuran lignan (+)-diayangambin [tetrahydro-1,4-bis(3,4,5-trimethoxyphenyl)-(1 R)-1alpha,3abeta,4alpha,6abeta-1 H,3 H-furo [3,4- c]furan] was evaluated in vitro and in vivo for its immunomodulatory and anti-inflammatory efficacy. Human mononuclear cell proliferation was inhibited by diayangambin with an IC 50 value of 1.5 (0.

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