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Sanabria-Ríos DJ, Morales-Guzmán C, Mooney J, Medina S, Pereles-De-León T, Rivera-Román A, Ocasio-Malavé C, Díaz D, Chorna N, Carballeira NM. Antibacterial Activity of Hexadecynoic Acid Isomers toward Clinical Isolates of Multidrug-Resistant Staphylococcus aureus. Lipids 2020; 55:101-116. [PMID: 31975430 DOI: 10.1002/lipd.12213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 12/16/2019] [Accepted: 01/06/2020] [Indexed: 11/07/2022]
Abstract
In the present study, the structural characteristics that impart antibacterial activity to C16 alkynoic fatty acids (aFA) were further investigated. The syntheses of hexadecynoic acids (HDA) containing triple bonds at C-3, C-6, C-8, C-9, C-10, and C-12 were carried out in four steps and with an overall yield of 34-78%. In addition, HDA analogs containing a sulfur atom at either C-4 or C-5 were also prepared in 69-77% overall yields, respectively. Results from this study revealed that the triple bond at C-2 is pivotal for the antibacterial activity displayed by 2-HDA, while the farther the position of the triple bond from the carbonyl group, the lower its bactericidal activity against gram-positive bacteria, including clinical isolates of methicillin-resistant Staphylococcus aureus (CIMRSA) strains. The potential of 2-HDA as an antibacterial agent was also assessed in five CIMRSA strains that were resistant to Ciprofloxacin (Cipro) demonstrating that 2-HDA was the most effective treatment in inhibiting their growth when compared with either Cipro alone or equimolar combinations of Cipro and 2-HDA. Moreover, it was proved that the inhibition of S. aureus DNA gyrase can be linked to the antibacterial activity displayed by 2-HDA. Finally, it was determined that the ability of HDA analogs to form micelles can be linked to their decreased activity against gram-positive bacteria, since critical micellar concentrations (CMC) between 50 and 300 μg/mL were obtained.
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Affiliation(s)
- David J Sanabria-Ríos
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR, 00919, USA
| | - Christian Morales-Guzmán
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, 17 Ave Universidad STE 1701, San Juan, PR, 00925, USA
| | - Joseph Mooney
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR, 00919, USA
| | - Solymar Medina
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR, 00919, USA
| | - Tomás Pereles-De-León
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR, 00919, USA
| | - Ashley Rivera-Román
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR, 00919, USA
| | - Carlimar Ocasio-Malavé
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR, 00919, USA
| | - Damarith Díaz
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR, 00919, USA
| | - Nataliya Chorna
- Department of Biochemistry, University of Puerto Rico, Medical Sciences, Campus, PO Box 365067, San Juan, PR, 00936, USA
| | - Néstor M Carballeira
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, 17 Ave Universidad STE 1701, San Juan, PR, 00925, USA
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2
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Boudaher E, Shaffer CL. Inhibiting bacterial secretion systems in the fight against antibiotic resistance. MEDCHEMCOMM 2019; 10:682-692. [PMID: 31741728 DOI: 10.1039/c9md00076c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 04/22/2019] [Indexed: 12/11/2022]
Abstract
Antimicrobial resistance is a mounting global health crisis that threatens a resurgence of life-threatening bacterial infections. Despite intensive drug discovery efforts, the rate of antimicrobial resistance outpaces the discovery of new antibiotic agents. One of the major mechanisms driving the rapid propagation of antibiotic resistance is bacterial conjugation mediated by the versatile type IV secretion system (T4SS). The search for therapeutic compounds that prevent the spread of antibiotic resistance via T4SS-dependent mechanisms has identified several promising molecular scaffolds that disrupt resistance determinant dissemination. In this brief review, we highlight the progress and potential of conjugation inhibitors and anti-virulence compounds that target diverse T4SS machineries. These studies provide a solid foundation for the future development of potent, dual-purpose molecular scaffolds that can be used as biochemical tools to probe type IV secretion mechanisms and target bacterial conjugation in clinical settings to prevent the dissemination of antibiotic resistance throughout microbial populations.
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Affiliation(s)
- Elizabeth Boudaher
- University of Kentucky , Department of Veterinary Science , Gluck Equine Research Center , 1400 Nicholasville Road , Lexington , KY , USA . ; Tel: +1 (859) 218 1168
| | - Carrie L Shaffer
- University of Kentucky , Department of Veterinary Science , Gluck Equine Research Center , 1400 Nicholasville Road , Lexington , KY , USA . ; Tel: +1 (859) 218 1168.,University of Kentucky , Department of Microbiology, Immunology, and Molecular Genetics , 800 Rose Street , Lexington , KY , USA.,University of Kentucky , Department of Pharmaceutical Sciences , 789 South Limestone Street , Lexington , KY , USA
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3
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Húmpola MV, Rey MC, Carballeira NM, Simonetta AC, Tonarelli GG. Biological and structural effects of the conjugation of an antimicrobial decapeptide with saturated, unsaturated, methoxylated and branched fatty acids. J Pept Sci 2016; 23:45-55. [PMID: 28025839 DOI: 10.1002/psc.2958] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 11/18/2016] [Accepted: 11/21/2016] [Indexed: 11/09/2022]
Abstract
The increasing bacterial resistance against conventional antibiotics has led to the search for new antimicrobial drugs with different modes of action. Cationic antimicrobial peptides (AMPs) and lipopeptides are promising candidates to treat infections because they act on bacterial membranes causing rapid destruction of sensitive bacteria. In this study, a decapeptide named A2 (IKQVKKLFKK) was conjugated at the N-terminus with saturated, unsaturated, methoxylated and methyl -branched fatty acids of different chain lengths (C8 - C20), the antimicrobial and structural properties of the lipopeptides being then investigated. The attachment of the fatty acid chain significantly improved the antimicrobial activity of A2 against bacteria, and so, endowed it with moderated antifungal activity against yeast strains belonging to genus Candida. Lipopeptides containing hydrocarbon chain lengths between C8 and C14 were the best antibacterial compounds (MIC = 0.7 to 5.8 μM), while the most active compounds against yeast were A2 conjugated with methoxylated and enoic fatty acids (11.1 to 83.3 μM). The improvement in antimicrobial activity was mainly related to the amphipathic secondary structure adopted by A2 lipopeptides in the presence of vesicles that mimic bacterial membranes. Peptide conjugation with long hydrocarbon chains (C12 or more), regardless of their structure, significantly increased toxicity towards eukaryotic cells, resulting in a loss of selectivity. These findings suggest that A2-derived lipopeptides are potential good candidates for the treatment of infectious diseases caused by bacteria and opportunistic pathogenic yeast belonging to genus Candida. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.
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Affiliation(s)
- María Verónica Húmpola
- Departamento de Química Orgánica, Facultad de Bioquímica y Cs. Biológicas, Universidad Nacional del Litoral, UNL. Ciudad Universitaria, Santa Fe, Argentina
| | - María Carolina Rey
- Departamento de Química Orgánica, Facultad de Bioquímica y Cs. Biológicas, Universidad Nacional del Litoral, UNL. Ciudad Universitaria, Santa Fe, Argentina
| | - Nestor M Carballeira
- Department of Chemistry, University of Puerto Rico, PO Box 23346, San Juan, 00931-3346, Puerto Rico
| | - Arturo Carlos Simonetta
- Cátedras de Microbiología y Biotecnología, Departamento de Ingeniería en Alimentos, Facultad de Ingeniería Química, UNL. Santiago del Estero, 2829, Santa Fe, Argentina
| | - Georgina Guadalupe Tonarelli
- Departamento de Química Orgánica, Facultad de Bioquímica y Cs. Biológicas, Universidad Nacional del Litoral, UNL. Ciudad Universitaria, Santa Fe, Argentina
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4
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Ripoll-Rozada J, García-Cazorla Y, Getino M, Machón C, Sanabria-Ríos D, de la Cruz F, Cabezón E, Arechaga I. Type IV traffic ATPase TrwD as molecular target to inhibit bacterial conjugation. Mol Microbiol 2016; 100:912-21. [PMID: 26915347 DOI: 10.1111/mmi.13359] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Bacterial conjugation is the main mechanism responsible for the dissemination of antibiotic resistance genes. Hence, the search for specific conjugation inhibitors is paramount in the fight against the spread of these genes. In this pursuit, unsaturated fatty acids have been found to specifically inhibit bacterial conjugation. Despite the growing interest on these compounds, their mode of action and their specific target remain unknown. Here, we identified TrwD, a Type IV secretion traffic ATPase, as the molecular target for fatty acid-mediated inhibition of conjugation. Moreover, 2-alkynoic fatty acids, which are also potent inhibitors of bacterial conjugation, are also powerful inhibitors of the ATPase activity of TrwD. Characterization of the kinetic parameters of ATPase inhibition has led us to identify the catalytic mechanism by which fatty acids exert their activity. These results open a new avenue for the rational design of inhibitors of bacterial conjugation in the fight against the dissemination of antibiotic resistance genes.
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Affiliation(s)
- Jorge Ripoll-Rozada
- Departamento de Biología Molecular and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
| | - Yolanda García-Cazorla
- Departamento de Biología Molecular and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
| | - María Getino
- Departamento de Biología Molecular and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
| | - Cristina Machón
- Departamento de Biología Molecular and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
| | - David Sanabria-Ríos
- Inter American University of Puerto Rico-Metropolitan Campus, Faculty of Science and Technology, San Juan, Puerto Rico
| | - Fernando de la Cruz
- Departamento de Biología Molecular and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
| | - Elena Cabezón
- Departamento de Biología Molecular and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
| | - Ignacio Arechaga
- Departamento de Biología Molecular and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
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5
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Getino M, Fernández-López R, Palencia-Gándara C, Campos-Gómez J, Sánchez-López JM, Martínez M, Fernández A, de la Cruz F. Tanzawaic Acids, a Chemically Novel Set of Bacterial Conjugation Inhibitors. PLoS One 2016; 11:e0148098. [PMID: 26812051 PMCID: PMC4727781 DOI: 10.1371/journal.pone.0148098] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/13/2016] [Indexed: 11/19/2022] Open
Abstract
Bacterial conjugation is the main mechanism for the dissemination of multiple antibiotic resistance in human pathogens. This dissemination could be controlled by molecules that interfere with the conjugation process. A search for conjugation inhibitors among a collection of 1,632 natural compounds, identified tanzawaic acids A and B as best hits. They specially inhibited IncW and IncFII conjugative systems, including plasmids mobilized by them. Plasmids belonging to IncFI, IncI, IncL/M, IncX and IncH incompatibility groups were targeted to a lesser extent, whereas IncN and IncP plasmids were unaffected. Tanzawaic acids showed reduced toxicity in bacterial, fungal or human cells, when compared to synthetic conjugation inhibitors, opening the possibility of their deployment in complex environments, including natural settings relevant for antibiotic resistance dissemination.
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Affiliation(s)
- María Getino
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria–Consejo Superior de Investigaciones Científicas, Santander, Cantabria, Spain
| | - Raúl Fernández-López
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria–Consejo Superior de Investigaciones Científicas, Santander, Cantabria, Spain
| | - Carolina Palencia-Gándara
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria–Consejo Superior de Investigaciones Científicas, Santander, Cantabria, Spain
| | - Javier Campos-Gómez
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria–Consejo Superior de Investigaciones Científicas, Santander, Cantabria, Spain
| | | | | | | | - Fernando de la Cruz
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria–Consejo Superior de Investigaciones Científicas, Santander, Cantabria, Spain
- * E-mail:
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Sanabria-Ríos DJ, Rivera-Torres Y, Maldonado-Domínguez G, Domínguez I, Ríos C, Díaz D, Rodríguez JW, Altieri-Rivera JS, Ríos-Olivares E, Cintrón G, Montano N, Carballeira NM. Antibacterial activity of 2-alkynoic fatty acids against multidrug-resistant bacteria. Chem Phys Lipids 2013; 178:84-91. [PMID: 24365283 DOI: 10.1016/j.chemphyslip.2013.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 12/10/2013] [Accepted: 12/12/2013] [Indexed: 10/25/2022]
Abstract
The first study aimed at determining the structural characteristics needed to prepare antibacterial 2-alkynoic fatty acids (2-AFAs) was accomplished by synthesizing several 2-AFAs and other analogs in 18-76% overall yields. Among all the compounds tested, the 2-hexadecynoic acid (2-HDA) displayed the best overall antibacterial activity against Gram-positive Staphylococcus aureus (MIC=15.6 μg/mL), Staphylococcus saprophyticus (MIC=15.5 μg/mL), and Bacillus cereus (MIC=31.3 μg/mL), as well as against the Gram-negative Klebsiella pneumoniae (7.8 μg/mL) and Pseudomonas aeruginosa (MIC=125 μg/mL). In addition, 2-HDA displayed significant antibacterial activity against methicillin-resistant S. aureus (MRSA) ATCC 43300 (MIC=15.6 μg/mL) and clinical isolates of MRSA (MIC=3.9 μg/mL). No direct relationship was found between the antibacterial activity of 2-AFAs and their critical micelle concentration (CMC) suggesting that the antibacterial properties of these fatty acids are not mediated by micelle formation. It was demonstrated that the presence of a triple bond at C-2 and the carboxylic acid moiety in 2-AFAs are important for their antibacterial activity. 2-HDA has the potential to be further evaluated for use in antibacterial formulations.
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Affiliation(s)
- David J Sanabria-Ríos
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR 00919, United States.
| | - Yaritza Rivera-Torres
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR 00919, United States
| | - Gamalier Maldonado-Domínguez
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR 00919, United States
| | - Idializ Domínguez
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR 00919, United States
| | - Camille Ríos
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR 00919, United States
| | - Damarith Díaz
- Faculty of Science and Technology, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR 00919, United States
| | - José W Rodríguez
- Department of Microbiology and Immunology, Universidad Central del Caribe School of Medicine, PO Box 60327, Bayamón, PR 00960, United States
| | - Joanne S Altieri-Rivera
- Department of Microbiology and Immunology, Universidad Central del Caribe School of Medicine, PO Box 60327, Bayamón, PR 00960, United States
| | - Eddy Ríos-Olivares
- Department of Microbiology and Immunology, Universidad Central del Caribe School of Medicine, PO Box 60327, Bayamón, PR 00960, United States
| | - Gabriel Cintrón
- Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, PO Box 23346, San Juan, PR 00931-3346, United States
| | - Nashbly Montano
- Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, PO Box 23346, San Juan, PR 00931-3346, United States
| | - Néstor M Carballeira
- Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, PO Box 23346, San Juan, PR 00931-3346, United States
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7
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Carballeira NM. Recent developments in the antiprotozoal and anticancer activities of the 2-alkynoic fatty acids. Chem Phys Lipids 2013; 172-173:58-66. [PMID: 23727443 DOI: 10.1016/j.chemphyslip.2013.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 05/03/2013] [Accepted: 05/06/2013] [Indexed: 12/21/2022]
Abstract
The 2-alkynoic fatty acids are an interesting group of synthetic compounds that display antimycobacterial, antifungal, anticancer, and pesticidal activities but their antiprotozoal activity has received little attention until recently. In this review we have summarized our present knowledge of the biomedical potential of the 2-hexadecynoic acid (2-HDA) and 2-octadecynoic acid (2-ODA) together with several mechanistic pieces of work attesting to the fact that these compounds, and their metabolites, are good fatty acid biosynthesis inhibitors. The antiprotozoal activity of 2-HDA and 2-ODA against Leishmania donovani and Plasmodium falciparum, parasites responsible for visceral leishmaniasis and malaria, respectively, is also reviewed. The evidence obtained so far supports the fact that these fatty acids are good inhibitors of the L. donovani DNA topoisomerase IB enzyme (LdTopIB) and the potency of LdTopIB inhibition is chain length dependent. We also demonstrate the generality of the antiprotozoal activity of 2-HDA and 2-ODA against P. falciparum, and review our present knowledge of their inhibition of key P. falciparum enzymes such as PfFabZ, PfFabG, and PfFabI together with some possible modes of inhibition. Recent research by our group has also demonstrated that 2-ODA displays antineoplastic activity, specifically against the neuroblastoma SH-SY5Y cell line via lactate dehydrogenase (LDH) release, which is a cell death mechanism principally associated to necrosis. This is the first comprehensive review of the medicinal chemistry of this interesting group of acetylenic fatty acids.
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Affiliation(s)
- Néstor M Carballeira
- Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, PO Box 23346, San Juan 00931-3346, Puerto Rico.
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8
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Li XC, Babu KS, Jacob MR, Khan SI, Agarwal AK, Clark AM. Natural Product Based 6-Hydroxy-2,3,4,6-tetrahydropyrrolo[1,2-a]pyrimidinium Scaffold as A New Antifungal Template. ACS Med Chem Lett 2011; 2:391-395. [PMID: 21743827 DOI: 10.1021/ml200020h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Synthetic analogues of the marine-derived class of natural products phloeodictines have been prepared and exhibited potent in vitro fungicidal activities against a broad array of fungal pathogens including drug resistant strains. The 6-hydroxy-2,3,4,6-tetrahydropyrrolo[1,2-a]pyrimidinium structural moiety with a C12 to C16 aliphatic side chain at C-6 has been shown to be the antifungal pharmacophore and may serve as a new antifungal template for further lead optimization.
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Affiliation(s)
- Xing-Cong Li
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, and ‡Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, University, Mississippi 38677, United States
| | - K. Suresh Babu
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, and ‡Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, University, Mississippi 38677, United States
| | - Melissa R. Jacob
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, and ‡Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, University, Mississippi 38677, United States
| | - Shabana I. Khan
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, and ‡Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, University, Mississippi 38677, United States
| | - Ameeta K. Agarwal
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, and ‡Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, University, Mississippi 38677, United States
| | - Alice M. Clark
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, and ‡Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, University, Mississippi 38677, United States
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Augustin KE, Schäfer HJ. Alkynic fatty acids: ω-Arylation, methoxycarbonylation to α,β-unsaturated esters, cyclotrimerization to pyridines and 2-pyridones. EUR J LIPID SCI TECH 2010. [DOI: 10.1002/ejlt.201000116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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10
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Tasdemir D, Sanabria D, Lauinger IL, Tarun A, Herman R, Perozzo R, Zloh M, Kappe SH, Brun R, Carballeira NM. 2-Hexadecynoic acid inhibits plasmodial FAS-II enzymes and arrests erythrocytic and liver stage Plasmodium infections. Bioorg Med Chem 2010; 18:7475-85. [PMID: 20855214 PMCID: PMC2981824 DOI: 10.1016/j.bmc.2010.08.055] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 07/14/2010] [Accepted: 08/29/2010] [Indexed: 11/24/2022]
Abstract
Acetylenic fatty acids are known to display several biological activities, but their antimalarial activity has remained unexplored. In this study, we synthesized the 2-, 5-, 6-, and 9-hexadecynoic acids (HDAs) and evaluated their in vitro activity against erythrocytic (blood) stages of Plasmodium falciparum and liver stages of Plasmodium yoelii infections. Since the type II fatty acid biosynthesis pathway (PfFAS-II) has recently been shown to be indispensable for liver stage malaria parasites, the inhibitory potential of the HDAs against multiple P. falciparum FAS-II (PfFAS-II) elongation enzymes was also evaluated. The highest antiplasmodial activity against blood stages of P. falciparum was displayed by 5-HDA (IC(50) value 6.6 μg/ml), whereas the 2-HDA was the only acid arresting the growth of liver stage P. yoelii infection, in both flow cytometric assay (IC(50) value 2-HDA 15.3 μg/ml, control drug atovaquone 2.5 ng/ml) and immunofluorescence analysis (IC(50) 2-HDA 4.88 μg/ml, control drug atovaquone 0.37 ng/ml). 2-HDA showed the best inhibitory activity against the PfFAS-II enzymes PfFabI and PfFabZ with IC(50) values of 0.38 and 0.58 μg/ml (IC(50) control drugs 14 and 30 ng/ml), respectively. Enzyme kinetics and molecular modeling studies revealed valuable insights into the binding mechanism of 2-HDA on the target enzymes. All HDAs showed in vitro activity against Trypanosoma brucei rhodesiense (IC(50) values 3.7-31.7 μg/ml), Trypanosoma cruzi (only 2-HDA, IC(50) 20.2 μg/ml), and Leishmania donovani (IC(50) values 4.1-13.4 μg/ml) with generally low or no significant toxicity on mammalian cells. This is the first study to indicate therapeutic potential of HDAs against various parasitic protozoa. It also points out that the malarial liver stage growth inhibitory effect of the 2-HDA may be promoted via PfFAS-II enzymes. The lack of cytotoxicity, lipophilic nature, and calculated pharmacokinetic properties suggests that 2-HDA could be a useful compound to study the interaction of fatty acids with these key P. falciparum enzymes.
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Affiliation(s)
- Deniz Tasdemir
- Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom.
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11
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Li XC, Jacob MR, Khan SI, Ashfaq MK, Babu KS, Agarwal AK, Elsohly HN, Manly SP, Clark AM. Potent in vitro antifungal activities of naturally occurring acetylenic acids. Antimicrob Agents Chemother 2008; 52:2442-8. [PMID: 18458131 PMCID: PMC2443879 DOI: 10.1128/aac.01297-07] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 01/06/2008] [Accepted: 04/26/2008] [Indexed: 11/20/2022] Open
Abstract
Our continuing effort in antifungal natural product discovery has led to the identification of five 6-acetylenic acids with chain lengths from C(16) to C(20): 6-hexadecynoic acid (compound 1), 6-heptadecynoic acid (compound 2), 6-octadecynoic acid (compound 3), 6-nonadecynoic acid (compound 4), and 6-icosynoic acid (compound 5) from the plant Sommera sabiceoides. Compounds 2 and 5 represent newly isolated fatty acids. The five acetylenic acids were evaluated for their in vitro antifungal activities against Candida albicans, Candida glabrata, Candida krusei, Candida tropicalis, Candida parapsilosis, Cryptococcus neoformans, Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Trichophyton mentagrophytes, and Trichophyton rubrum by comparison with the positive control drugs amphotericin B, fluconazole, ketoconazole, caspofungin, terbinafine, and undecylenic acid. The compounds showed various degrees of antifungal activity against the 21 tested strains. Compound 4 was the most active, in particular against the dermatophytes T. mentagrophytes and T. rubrum and the opportunistic pathogens C. albicans and A. fumigatus, with MICs comparable to several control drugs. Inclusion of two commercially available acetylenic acids, 9-octadecynoic acid (compound 6) and 5,8,11,14-eicosatetraynoic acid (compound 7), in the in vitro antifungal testing further demonstrated that the antifungal activities of the acetylenic acids were associated with their chain lengths and positional triple bonds. In vitro toxicity testing against mammalian cell lines indicated that compounds 1 to 5 were not toxic at concentrations up to 32 muM. Furthermore, compounds 3 and 4 did not produce obvious toxic effects in mice at a dose of 34 mumol/kg of body weight when administered intraperitoneally. Taking into account the low in vitro and in vivo toxicities and significant antifungal potencies, these 6-acetylenic acids may be excellent leads for further preclinical studies.
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Affiliation(s)
- Xing-Cong Li
- National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, School of Pharmacy, The University of Mississippi, University, MS 38677, USA.
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Carballeira NM. New advances in fatty acids as antimalarial, antimycobacterial and antifungal agents. Prog Lipid Res 2007; 47:50-61. [PMID: 18023422 DOI: 10.1016/j.plipres.2007.10.002] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2007] [Revised: 10/03/2007] [Accepted: 10/24/2007] [Indexed: 11/30/2022]
Abstract
This review deals with the most recent findings on the antimalarial, antimycobacterial, and antifungal properties of fatty acids, with particular emphasis on novel marine fatty acids. The first section deals with the most recent and some background literature on what has been the latest developments with respect to fatty acids as antimalarial agents and the importance of enzyme inhibition, in particular the inhibition of the enoyl-ACP reductase (FabI) of Plasmodium falciparum, the principal agent responsible for malaria. This section of the review also emphasizes the latest antimalarial research with the very long-chain Delta5,9 fatty acids from sponges. The second section of the review deals with the recent literature on the antimycobacterial activity of fatty acids and the importance of enzyme inhibition, in particular the inhibition of the enoyl-ACP reductase (InhA) of Mycobacterium tuberculosis for antimycobacterial activity. The inhibitory activities of the Delta5,9 fatty acids against InhA as well as that of the alpha-methoxylated fatty acids are also discussed. The importance of Delta5,9 fatty acids as topoisomerase I inhibitors and its connection to cancer is also reviewed. The last part of the review, the antifungal section, also emphasizes the most recent research with antifungal fatty acids and the importance of enzyme inhibition, in particular N-myristoyltransferase (NMT) inhibition, for antifungal activity. This last section of the review emphasizes the latest research with the alpha-methoxylated fatty acids but the importance of acetylenic fatty acids is also considered.
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Affiliation(s)
- N M Carballeira
- Department of Chemistry, University of Puerto Rico, P.O. Box 23346, San Juan 00931-3346, Puerto Rico.
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Carballeira NM, Sanabria D, Cruz C, Parang K, Wan B, Franzblau S. 2,6-hexadecadiynoic acid and 2,6-nonadecadiynoic acid: novel synthesized acetylenic fatty acids as potent antifungal agents. Lipids 2006; 41:507-11. [PMID: 16933795 PMCID: PMC1626269 DOI: 10.1007/s11745-006-5124-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The hitherto unknown 2,6-hexadecadiynoic acid, 2,6-nonadecadiynoic acid, and 2,9-hexadecadiynoic acid were synthesized in two steps and in 11-18% overall yields starting from either 1,5-hexadiyne or 1,8-nonadiyne. Among all the compounds 2,6-hexadecadiynoic acid displayed the best overall antifungal activity against both the fluconazole-resistant Candida albicans strains ATCC 14053 and ATCC 60193, with a minimum inhibitory concentration (MIC of 11 microM), and against Cryptococcus neoformans ATCC 66031 (MIC < 5.7 microM). 2,9-Hexadecadiynoic acid did not display any significant cytotoxicity against the fluconazole-resistant C. albicans strains, but it showed fungitoxicity against C. neoformans ATCC 66031 with a MIC value of < 5.8 microM. Other FA, such as 2-hexadecynoic acid, 5-hexadecynoic acid, 9-hexadecynoic acid, and 6-nonadecynoic acid were also synthesized and their antifungal activities compared with those of the novel acetylenic FA. 2-Hexadecynoic acid, a known antifungal FA, exhibited the best antifungal activity (MIC = 9.4 microM) against the fluconazole-resistant C. albicans ATCC 14053 strain, but it showed a MIC value of only 100 microM against C. albicans ATCC 60193. 2,6-Hexadecadiynoic acid and 2-hexadecynoic acid also displayed a MIC of 140-145 microM toward Mycobacterium tuberculosis H37Rv in Middlebrook 7H12 medium. In conclusion, 2,6-hexadecadiynoic acid exhibited the best fungitoxicity profile compared with other analogues. This diynoic FA has the potential to be further evaluated for use in topical antifungal formulations.
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Morbidoni HR, Vilchèze C, Kremer L, Bittman R, Sacchettini JC, Jacobs WR. Dual inhibition of mycobacterial fatty acid biosynthesis and degradation by 2-alkynoic acids. ACTA ACUST UNITED AC 2006; 13:297-307. [PMID: 16638535 DOI: 10.1016/j.chembiol.2006.01.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2005] [Revised: 12/29/2005] [Accepted: 01/05/2006] [Indexed: 11/24/2022]
Abstract
2-Hexadecynoic acid and 2-octadecynoic acid have cidal activity against Mycobacterium smegmatis and Mycobacterium bovis BCG. At subinhibitory concentrations, M. smegmatis rapidly transformed [1-(14)C]-2-hexadecynoic acid into endogenous fatty acids and elongated them into mycolic acids. Toxic concentrations of 2-hexadecynoic acid resulted in accumulation of 3-ketohexadecanoic acid, which blocked fatty acid biosynthesis, and 3-hexadecynoic acid, an inhibitor of fatty acid degradation. The combination of these two metabolites is necessary to achieve the inhibition of M. smegmatis. We conclude that 2- and 3-hexa/octadecynoic acids inhibit mycolic acid biosynthesis, fatty acid biosynthesis, and fatty acid degradation, pathways of significant importance for mycobacteria.
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Affiliation(s)
- Hector R Morbidoni
- Department of Microbiology and Immunology, Howard Hughes Medical Institute, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, USA
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Carballeira NM, Sanabria D, Parang K. Total synthesis and further scrutiny of the in vitro antifungal activity of 6-nonadecynoic acid. Arch Pharm (Weinheim) 2005; 338:441-3. [PMID: 16143955 DOI: 10.1002/ardp.200500102] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The antifungal, naturally occurring acetylenic fatty acid 6-nonadecynoic acid was synthesized in three steps (18 % overall yield), for the first time starting with commercially available 1-tetradecyne. The synthesis developed herein will facilitate the further study of the antifungal properties of this naturally occurring acetylenic fatty acid. The 6-nonadecynoic acid exhibited the best antifungal activity (< 4.3 microM) against Cryptococcus neoformans ATCC 66031 in Sabouraud Dextrose Broth (SDB) media. In our hands, it was not active against Candida albicans ATCC 14053 and Candida albicans ATCC 60193.
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