- Antibacterial Activity of Hexadecynoic Acid Isomers toward Clinical Isolates of Multidrug-Resistant Staphylococcus aureus
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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.
- Carballeira, Néstor M.,Chorna, Nataliya,Díaz, Damarith,Medina, Solymar,Mooney, Joseph,Morales-Guzmán, Christian,Ocasio-Malavé, Carlimar,Pereles-De-León, Tomás,Rivera-Román, Ashley,Sanabria-Ríos, David J.
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- 2-Hexadecynoic acid inhibits plasmodial FAS-II enzymes and arrests erythrocytic and liver stage Plasmodium infections
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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 (IC50 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 (IC50 value 2-HDA 15.3 μg/ml, control drug atovaquone 2.5 ng/ml) and immunofluorescence analysis (IC50 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 (IC50 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 (IC50 values 3.7-31.7 μg/ml), Trypanosoma cruzi (only 2-HDA, IC50 20.2 μg/ml), and Leishmania donovani (IC50 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.
- Tasdemir, Deniz,Sanabria, David,Lauinger, Ina L.,Tarun, Alice,Herman, Rob,Perozzo, Remo,Zloh, Mire,Kappe, Stefan H.,Brun, Reto,Carballeira, Néstor M.
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scheme or table
p. 7475 - 7485
(2011/01/04)
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- A versatile approach to the synthesis of 9(Z)-unsaturated acyclic insect pheromones from undec-10-enoic acid
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A general approach to the synthesis of 9(Z)-unsaturated acyclic insect pheromones from undec-10-enoic acid was developed. The method comprises the conversion of the acid into undec-10-enyl acetate, shortening of its carbon chain to afford dec-9-enyl acetate (via 11-acetoxyundecanoic acid), and a two-step transformation of the latter into the key intermediate, dec-9-yn-1-ol, by sequential bromination - dehydrobromination. The elimination of two HBr molecules from the dibromide is effectively performed using Bu1OK in the presence of dibenzo-18-crown-6 as the catalyst.
- Ishmuratov,Kharisov,Yakovleva,Botsman,Galeeva,Ishmuratova,Tolstikov
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p. 1595 - 1597
(2007/10/03)
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- Use of enyne compounds in the synthesis of insect pheromones
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A new approach has been developed to the synthesis of monogenic insect pheromones with acetogenin and macrolide structures, using the low reactivity of ozone and of 9-borabicyclo[3.3.1]nonane towards an acetylenic function as compared with a vinyl function.
- Ishmuratov,Ishmuratova,Odinokov,Tolstikov
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- INSECT PHEROMONES AND THEIR ANALOGUES. XVI. PRACTICAL SYNTHESIS OF HEXADEC-9Z-ENAL - A COMPONENT OF THE SEX PHEROMONE OF THE COTTON BOLLWORM Heliothis armigera
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A synthesis of hexadec-9Z-enal - a component of the sex pheromone of the cotton bollworm Heliothis armigera (Huebner) - based on cyclooctene (I) is proposed.Through a solution of 22 g of (I), 250 ml of cyclohexane, and 40 ml of MeOH is passed (at 5 deg C) 0.2 M O3/O2, the solution is decanted off, and the precipitated ozonide is dissolved in 200 ml of MeOH and is reduced with 19 g of NaBH4 (40 deg C) with the isolation, after the usual working up, of 23.4 g of octane-1,8-diol (II).From 0.5 mole of (II) and 0.6 mole of 45percent HBr 8-bromooctan-1-ol (III) is obtained and this is converted into 1-(2-(THPL)oxy)-8-bromooctane (IV).The condensation of (IV) with oct-1-yne (Ar, LiNH2, HMPTA, 10 deg C, 1 h, and then 55 deg C, 10 h) leads to 1-(2-THPL-oxy)hexadec-9-yne (V) the hydrolysis of which (MeOH, H2O, p-TsOH, 20 deg C for 20 h) yields hexadec-9-yn-ol (VI).The reduction of (VI) (Et2O, iso-BuMgBr, Cp2TiCl2, 0 deg C, 15 min, then 20 deg C, 1 h) yields hexadec-9Z-en-1-ol (VII).The oxidation of (VII) (PyHCrO3+ Cl-, CH2Cl2, 20 deg C, 2 h) gives hexadec-9Z-enal (VIII).Characteristics of the compounds (yield (percent), nD20(25): (II) - 80, mp 61-62 deg C; (III) - 75, 1.4807; (IV) - 99, -; (V) - 52, 1,4650; (VI) - 85, 1.4657; (VII) - 99, 1.4650; (VIII) - 98, 1.4600.Characteristics of the IR and PMR spectra of compounds (V-VII) are given.
- Odinolov, V. N.,Dzhemilev, U. M.,Ishmuratov, G. Yu.,Botsman, L. P.,Vostrikova, O. S.,et al.
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p. 242 - 244
(2007/10/02)
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- A Convient Synthesis of (Z)-9-Hexadecen-1-yl Acetate, a Sex Pheromone of Rice Green Caterpillar, Naranga aenescens, from Aleuritic Acid
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Aleuritic acid (2) is converted into the 16-hydroxyolefinic acid (3) via ethyl orthoformate reaction and pyrolysis.The methyl ester (4) of (3) on mesylation followed by lithium aluminium hydride reduction gives the olefin alcohol (6).This is converted into Z-olefin alcohol (9) via the acetylene route and acetylated to afford the desired pheromone (1)
- Chattopadhyay, S.,Mamdapur, V. R.,Chadha, M. S.
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p. 236 - 237
(2007/10/02)
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- CI(NO) Spectra of n-Alkyn-1-ols
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n-Alkyn-1-ols show fragmentation patterns which are influenced by the length of the chain and by the relative positions of the hydroxyl group and triple bond, and which allow a localization of the site of unsaturation.
- Brauner, A.,Budzikiewicz, H.
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p. 324 - 326
(2007/10/02)
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