- Polyhydroxyalkanoate-based 3-hydroxyoctanoic acid and its derivatives as a platform of bioactive compounds
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A library of 18 different compounds was synthesized starting from (R)-3-hydroxyoctanoic acid which is derived from the bacterial polymer polyhydroxyalkanoate (PHA). Ten derivatives, including halo and unsaturated methyl and benzyl esters, were synthesized and characterized for the first time. Given that (R)-3-hydroxyalkanoic acids are known to have biological activity, the new compounds were evaluated for antimicrobial activity and in vitro antiproliferative effect with mammalian cell lines. The presence of the carboxylic group was essential for the antimicrobial activity, with minimal inhibitory concentrations against a panel of bacteria (Gram-positive and Gram-negative) and fungi (Candida albicans and Microsporum gypseum) in the range 2.87.0 mM and 0.16.3 mM, respectively. 3-Halogenated octanoic acids exhibited the ability to inhibit C. albicans hyphae formation. In addition, (R)-3-hydroxyoctanoic and (E)-oct-2-enoic acids inhibited quorum sensing-regulated pyocyanin production in the opportunistic pathogen Pseudomonas aeruginosa PAO1. Generally, derivatives did not inhibit mammalian cell proliferation even at 3-mM concentrations, while only (E)-oct-2-enoic and 3-oxooctanoic acid had IC50 values of 1.7 and 1.6 mM with the human lung fibroblast cell line.
- Radivojevic, Jelena,Skaro, Sanja,Senerovic, Lidija,Vasiljevic, Branka,Guzik, Maciej,Kenny, Shane T.,Maslak, Veselin,Nikodinovic-Runic, Jasmina,OConnor, Kevin E.
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p. 161 - 172
(2016/01/09)
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- Fatty acyl incorporation in the biosynthesis of WAP-8294A, a group of potent anti-MRSA cyclic lipodepsipeptides
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WAP-8294A is a family of at least 20 cyclic lipodepsipeptides exhibiting potent anti-MRSA activity. These compounds differ mainly in the hydroxylated fatty acyl chain; WAP-8294A2, the most potent member of the family that reached clinical trials, is based on (R)-3-hydroxy-7-methyloctanoic acid. It is unclear how the acyl group is incorporated because no acyl-CoA ligase (ACL) gene is present in the WAP-8294A gene cluster in Lysobacter enzymogenes OH11. Here, we identified seven putative ACL genes in the OH11 genome and showed that the yield of WAP-8294A2 was impacted by multiple ACL genes with the ACL6 gene having the most significant effect. We then investigated several (R)-3-hydroxy fatty acids and their acyl SNAC (N-acetylcysteamine) thioesters as substrates for the ACLs. Feeding (R)-3-hydroxy-7-methyloctanoate-SNAC to the ACL6 gene deletion mutant restored the production of WAP-8294A2. Finally, we heterologously expressed the seven ACL genes in E. coli and purified six of the proteins. While these enzymes exhibit a varied level of activity in vitro, ACL6 showed the highest catalytic efficiency in converting (R)-3-hydroxy-7-methyloctanoic acid to its CoA thioester when incubated with coenzyme A and ATP. These results provided both in vivo and in vitro evidence to support the fact that ACL6 is the main player for fatty acyl activation and incorporation in WAP-8294A2 biosynthesis. The results also suggest that the molecular basis for the acyl chain diversity in the WAP-8294A family is the presence of functionally overlapping ACLs.
- Chen, Haotong,Olson, Andrew S.,Su, Wei,Dussault, Patrick H.,Du, Liangcheng
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p. 105753 - 105759
(2015/12/26)
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- Synthesis of enantiopure (R)-(-)-massoialactone through ruthenium-SYNPHOS asymmetric hydrogenation
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Total synthesis of enantiopure (R)-(-)-massoialactone was achieved. The key step includes the asymmetric hydrogenation of an achiral β-keto ester using a ruthenium-SYNPHOS catalyst to set the hydroxyl function in a stereocontrolled manner with excellent enantioselectivity (>99% ee). Ring closing metathesis (RCM) in the presence of Grubbs' catalyst allows the final construction of the six-membered lactone.
- Touati, Ridha,Ratovelomanana-Vidal, Virginie,Hassine, Bechir Ben,Genet, Jean-Pierre
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p. 3400 - 3405
(2007/10/03)
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- An improved asymmetric Reformatsky reaction mediated by (-)-N,N-dimethylaminoisoborneol
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(-)-N,N-Dimethylaminoisoborneol ((-)-DAIB) was found to be an excellent ligand for the enantioselective addition of Reformatsky reagents to aromatic and aliphatic aldehydes. Enantioselectivities up to 93% ee were obtained with sulfur-containing aldehydes.
- Kloetzing, Ralf J.,Thaler, Tobias,Knochel, Paul
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p. 1125 - 1128
(2007/10/03)
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- Optically active compound and process for producing the same
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An optically active (2S,3R)-2-(3'-hydroxyacyl)aminoalkane-1,3-diol and a process for producing the same are disclosed. The compound is represented by the following general formula (1): STR1 wherein R1 represents a linear or branched, saturated aliphatic hydrocarbon group having 9 to 19 carbon atoms; R2 represents a linear or branched, saturated aliphatic hydrocarbon group having 1 to 19 carbon atoms; and symbol * means that the carbon atom is an asymmetric carbon atom of the S or R configuration. The optically active compound is a ceramide in which the fatty acid moiety has an optically active hydroxyl group in the 3-position.
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- Optically active ceramides and process for producing the same
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An optically active (2S,3R)-2-(3'-hydroxyacyl)aminoalkane-1,3-diol and a process for producing the same are disclosed. The compound is represented by the following general formula (1): wherein R1represents a linear or branched, saturated aliphatic hydrocarbon group having 9 to 19 carbon atoms; R2represents a linear or branched, saturated aliphatic hydrocarbon group having 1 to 19 carbon atoms; and symbol * means that the carbon atom is an asymmetric carbon atom of the S or R configuration. The optically active compound is a ceramide in which the fatty acid moiety has an optically active hydroxyl group in the 3-position.
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- Tributyltin hydride-induced free radical deoxygenation of the cyclic thionocarbonates of threo-2,3-dihydroxy esters and ketones
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A practical and enantiospecific method for the synthesis of optically pure β-hydroxy esters and ketones is described. The key reaction is free radical deoxygenation of the cyclic thionocarbonates of threo-2,3-dihydroxy esters and ketones with tributyltin
- Rho, Ho-Sik
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p. 3887 - 3893
(2007/10/03)
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- Factors affecting the lipase catalyzed transesterification reactions of 3-hydroxy esters in organic solvents
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Chiral resolutions of racemic 3-hydroxy esters were performed in organic phases with lipases from Pseudomonas cepacia, Chromobacterium viscosum, and Porcine pancreas.The reaction conditions have been optimized with 3-hydroxy octanoic acid methyl ester.Different organic solvents have been tested showing a tendentious correlation with the hydrophobicity of the solvents expressed as log P.The reaction time was shortened six fold by using irreversible acylating agents.We have found solvent type, lipase type and acylating agent acting as tools for changing the enantioselectivity.Lipase from Pseudomonas cepacia was lyophilized at different pH and the influence of the amount of water added was investigated, resulting in the highest activity at the pH optimum and a denaturation of the lipase above 1 percent water (w/w lipase).The water activity was measured on-line with a humidity sensor.Water activities greater than 0.4 led to a decrease in enantioselectivity and reaction rate.In the optimized system the resolutions of other 3-hydroxy esters were tested.Aliphatic compounds reacted with lower enantioselectivity, only the substrates could be isolated in high enantiomeric purity.In contrast, aromatic 3-hydroxy esters were acylated by lipases with high stereoselectivity.A model of the active site of lipase from Pseudomonas sp. explained these experimental observations.
- Bornscheuer, Uwe,Herar, Andrea,Kreye, Lars,Wendel, Volker,Capewell, Andreas,et al.
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p. 1007 - 1016
(2007/10/02)
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- Asymmetric Reduction of Aliphatic Short- to Long-Chain β-Keto Acids by Use of Fermenting Bakers' Yeast
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Eleven β-keto acids, ranging from 3-oxobutanoic to 3-oxooctanoic acids, were reduced with fermenting bakers' yeast to the corresponding optically active β-hydroxy acids, which were isolated as the methyl esters.In all cases, the (R)-hydroxy acids were obtained in >/=98percent ee, except for 3-oxobutanoic acid, which afforded the (S)-hydroxy acid in 86percent ee.Inhibition of fermentation was observed for 3-oxoundecanoic to 3-oxotetradecanoic acids, leading to no reduction.Lowering of the substrate concentration was found to be appreciably effective in avoiding inhibition.
- Utaka, Masanori,Watabu, Hisashi,Higashi, Hiroshi,Sakai, Takashi,Tsuboi, Sadao,Torii, Sigeru
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p. 3917 - 3921
(2007/10/02)
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- Structural and Synthetic Studies of the Spore Germination Autoinhibitor Gloeosporone
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Gloeosporone 1 is an autoinhibitor of spore germination that was recently isolated from conidia of Colletotrichum gloeosporioides.The structure initially proposed by Meyer et al. contained an unusual oxocane ring system (1a).A stereoselective synthesis of
- Schreiber, Stuart L.,Kelly, Sarah E.,Porco, John A.,Sammakia, Tarek,Suh, Edward M.
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p. 6210 - 6218
(2007/10/02)
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- Synthesis of optically active forms of the δ-lactone of 3,5-dihydroxydecanoic acid
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The δ-lactone of 3,5-dihydroxydecanoic acid was synthesized from methyl-3-oxooctanoate by utilizing its baker's yeast reduction.
- Sato, Tsuguo
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p. 2732 - 2733
(2007/10/02)
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- The Preparation of Optically Pure 3-Hydroxybutanoic Acid and Its Homologues as the Dibenzylammonium Salt
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Optically pure (R)- and (S)-3-hydroxybutanoic acid and its homologues are prepared by the method consisting of the enantioface differentiating hydrogenation of methyl 3-oxoalkanoate to methyl 3-hydroxyalkanoate (80-90percent e.e.) over asymmetrically modified nickel catalyst and the preferential crystallization of optically pure 3-hydroxyalkanoic acids from the hydrogenation products as the dibenzylammonium salts.
- Kikukawa, Tadashi,Iizuka, Yoshitomi,Sugimura, Takashi,Harada, Tadao,Tai, Akira
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p. 1267 - 1270
(2007/10/02)
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- An Examination of the Extent of Diastereofacial Selection in the Reactions of a Chiral Nitrile Oxide with Achiral Alkenes: a Route to β-Hydroxy Carboxylic Acids
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A new synthesis of optically active β-hydroxy carboxylic acids has been developed which is based on the (modest) diastereoselective addition of the chiral nitrile oxide (4) to 1,2-disubstituted alkenes.
- Kozikowski, Alan P.,Kitagawa, Yoshinori,Springer, James P.
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p. 1460 - 1462
(2007/10/02)
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- Asymmetric Synthesis of Hydroxy Carboxylic Acids
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Optically-active hydroxy carboxylic acids of the general formula RCHOH(CH2)nCO2H are prepared from optically-active propargyl alcohols.
- Midland, M. Mark,Lee, Penny E.
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p. 3933 - 3934
(2007/10/02)
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