72864-23-4Relevant articles and documents
Structure of the unusual Sinorhizobium fredii HH103 lipopolysaccharide and its role in symbiosis
Di Lorenzo, Flaviana,Speciale, Immacolata,Silipo, Alba,Alías-Villegas, Cynthia,Acosta-Jurado, Sebastián,Rodríguez-Carvajal, Miguel-ángel,Dardanelli, Marta S.,Palmigiano, Angelo,Garozzo, Domenico,Ruiz-Sainz, José-Enrique,Molinaro, Antonio,Vinardell, José-María
, p. 10969 - 10987 (2021/01/07)
Rhizobia are soil bacteria that form important symbiotic associations with legumes, and rhizobial surface polysaccharides, such as K-antigen polysaccharide (KPS) and lipopolysaccharide (LPS), might be important for symbiosis. Previously, we obtained a mutant of Sinorhizobium fredii HH103, rkpA, that does not produce KPS, a homopolysaccharide of a pseudaminic acid derivative, but whose LPS electrophoretic profile was indistinguishable from that of the WT strain. We also previously demonstrated that the HH103 rkpLMNOPQ operon is responsible for 5-acetamido-3,5,7,9-tetradeoxy-7-(3-hydroxybutyramido)-L-glyc-ero-L-manno-nonulosonic acid [Pse5NAc7(3OHBu)] production and is involved in HH103 KPS and LPS biosynthesis and that an HH103 rkpM mutant cannot produce KPS and displays an altered LPS structure. Here, we analyzed the LPS structure of HH103 rkpA, focusing on the carbohydrate portion, and found that it contains a highly heterogeneous lipid A and a peculiar core oligosaccharide composed of an unusually high number of hexuronic acids containing b-configured Pse5NAc7(3OHBu). This pseudaminic acid derivative, in its a-configuration, was the only structural component of the S. fredii HH103 KPS and, to the best of our knowledge, has never been reported from any other rhizobial LPS. We also show that Pse5NAc7(3OHBu) is the complete or partial epitope for a mAb, NB6-228.22, that can recognize the HH103 LPS, but not those of most of the S. fredii strains tested here. We also show that the LPS from HH103 rkpM is identical to that of HH103 rkpA but devoid of any Pse5NAc7(3OHBu) residues. Notably, this rkpM mutant was severely impaired in symbiosis with its host, Macroptilium atropurpureum.
Rhamnolipid inspired lipopeptides effective in preventing adhesion and biofilm formation of Candida albicans
Jovanovic, Milos,Radivojevic, Jelena,O'Connor, Kevin,Blagojevic, Stevan,Begovic, Biljana,Lukic, Vera,Nikodinovic-Runic, Jasmina,Savic, Vladimir
supporting information, p. 209 - 217 (2019/03/23)
Rhamnolipids are biodegradable low toxic biosurfactants which exert antimicrobial and anti-biofilm properties. They have attracted much attention recently due to potential applications in areas of bioremediation, therapeutics, cosmetics and agriculture, however, the full potential of these versatile molecules is yet to be explored. Based on the facts that many naturally occurring lipopeptides are potent antimicrobials, our study aimed to explore the potential of replacing rhamnose in rhamnolipids with amino acids thus creating lipopeptides that would mimic or enhance properties of the parent molecule. This would allow not only for more economical and greener production but also, due to the availability of structurally different amino acids, facile manipulation of physico-chemical and biological properties. Our synthetic efforts produced a library of 43 lipopeptides revealing biologically more potent molecules. The structural changes significantly increased, in particular, anti-biofilm properties against Candida albicans, although surface activity of the parent molecule was almost completely abolished. Our findings show that the most active compounds are leucine derivatives of 3-hydroxy acids containing benzylic ester functionality. The SAR study demonstrated a further increase in activity with aliphatic chain elongation. The most promising lipopeptides 15, 23 and 36 at 12.5 μg/mL concentration allowed only 14.3%, 5.1% and 11.2% of biofilm formation, respectively after 24 h. These compounds inhibit biofilm formation by preventing adhesion of C. albicans to abiotic and biotic surfaces.
The synthesis of medium-chain-length β-hydroxy esters via the reformatsky reaction
Sailer, Miloslav,Dubicki, Krystyn I.,Sorensen, John L.
, p. 79 - 82 (2015/02/02)
The synthesis of medium-chain-length β-hydroxy esters in good yield via the Reformatsky reaction is described. This work will be used as the basis for further investigation of hydroxyalkanoate polymers as potential feedstock for biofuel production.
ANTIMICROBIAL AGENT
-
Paragraph 0038, (2015/02/05)
[Problem] To provide a novel antimicrobial agent that has excellent antimicrobial activity and which is prepared from an ester composed of propanediol and a β-hydroxycarboxylic acid. [Solution] An antimicrobial agent which is prepared from a propanediol mono-β-hydroxycarboxylic acid ester expressed by the following formula (1) or formula (2) (wherein R1 and R2 are both branched or unbranched, and saturated or unsaturated alkyl groups having 5 to 9 carbon atoms).
Total synthesis of fellutamide b and deoxy-fellutamides B, C, and D
Giltrap, Andrew M.,Cergol, Katie M.,Pang, Angel,Britton, Warwick J.,Payne, Richard J.
, p. 2382 - 2397 (2013/08/23)
The total syntheses of the marine-derived lipopeptide natural product fellutamide B and deoxy-fellutamides B, C, and D are reported. These compounds were accessed through a novel solid-phase synthetic strategy using Weinreb amide-derived resin. As part of the synthesis, a new enantioselective route to (3R)-hydroxy lauric acid was developed utilizing a Brown allylation reaction followed by an oxidative cleavage-oxidation sequence as the key steps. The activity of these natural products, and natural product analogues was also assessed against Mycobacterium tuberculosis in vitro.
Systematic investigation of the kinetic resolution of 3-hydroxy fatty acid esters using Candida antarctica lipase B (CALB) and the influence of competing oligomerization on the enantiomeric ratios
Braner, Markus,Zielonka, Stefan,Auras, Sylvia,Huettenhain, Stefan H.
experimental part, p. 1019 - 1025 (2012/02/01)
The kinetic resolution of 3-hydroxy fatty acid esters C8:0 to C16:0 with Candida antarctica lipase B shows common plots of the enantiomeric excesses of the product and substrate, respectively, versus the conversion and an enantiomeric ratio E of 27 calculated from ee(p). Differences in E, either calculated from the products or the substrates, could be explained by competing oligomerization as a second substrate-consuming process. This reaction is slow compared to acylation, and the remaining enantiomer was oligomerized. Taylor & Francis Group, LLC.
Gas chromatography/electron-capture negative ion mass spectrometry for the quantitative determination of 2- and 3-hydroxy fatty acids in bovine milk fat
Jenske, Ramona,Vetter, Walter
experimental part, p. 5500 - 5505 (2010/03/25)
2- and 3-hydroxy fatty acids (2- and 3-OH-FAs) are bioactive substances reported in sphingolipids and bacteria. Little is known of their occurrence in food. For this reason, a method suitable for the determination of OH-FAs at trace levels in bovine milk fat was developed. OH-FAs (and conventional fatty acids in samples) were converted into methyl esters and the hydroxyl group was derivatized with pentafluorobenzoyl (PFBO) chloride to give PFBO-O-FA methyl esters. These derivatives with strong electron affinity were determined by gas chromatography interfaced to mass spectrometry using electron-capture negative ion in the selected ion monitoring mode (GC/ECNI-MS-SIM). This method proved to be highly sensitive and selective for PFBO-O-FA methyl esters. For the analysis of samples, two internal standards were used. For this purpose, 9,10-dideutero-2-OH-18:0 methyl ester (ISTD-1) from 2-OH-18:1(9c) methyl ester as well as the ethyl ester of 3-PFBO-O-12:0 (ISTD-2) was synthesized. ISTD-1 served as a recovery standard whereas ISTD-2 was used for GC/MS measurements. The whole-sample cleanup consisted of accelerated solvent extraction of dry bovine milk, addition of ISTD 1, saponification, conversion of fatty acids into methyl esters by use of boron trifluoride, separation of the methyl esters of OH-FAs from nonsubstituted FAs on activated silica, conversion of OH-FAs methyl esters into PFBO-O-FA methyl esters, addition of ISTD-2, and measurement by GC/ECNI-MS-SIM. By this method, ten OH-FAs were quantified in bovine milk fat with high precision in the range from 0.02 ± 0.00 to 4.49 ± 0.29 mg/100 g of milk fat.
Polyhydroxyalkanoate and manufacturing method thereof
-
Page/Page column 31, (2008/06/13)
To provide a novel polyhydroxyalkanoate and a manufacturing method by a microorganism capable of substantially reducing unintended monomer units and obtaining the polyhydroxyalkanoate in a high yield. A microorganism capable of synthesizing a novel polyhydroxyalkanoate having 3-hydroxy-substituted benzoylalkanoic acid as a monomer unit using a substituted benzoylalkanoic acid as a material is cultured in the medium containing a substituted benzoylalkanoic acid, then the polyhydroxyalkanoate produced in the cultured bacteria is extracted and recovered.
Chemistry of metapleural gland secretions of three attine ants, Atta sexdens rubropilosa, Atta cephalotes, and Acromyrmex octospinosus (Hymenoptera: Formicidae)
Do Nascimento, Ruth R.,Schoeters, Eric,Morgan, E. David,Billen, Johan,Stradling, David J.
, p. 987 - 1000 (2007/10/03)
The chemical composition of the secretions of the metapleural glands of workers and soldiers of two Atta species, atta sexdens rubropilosa and A. cephalotes, and workers of Acromyrmex oetospinoxus, has been studied. As indicated by infrared spectrometry and confirmed by the ninhydrin test, the secretions contain chiefly proteins. Of the volatile acidic portion, which is present as ionized salts, phenylacetic acid is the major component in workers and soldiers of A. s. rubropilosa and A. cephalotes. Both Atta species also contain 3 hydroxydecanoic acid and its homolog as minor components together with indoleacetic acid. While there are qualitative similarities in the acidic composition in the secretions of A. s. rubropilosa and A. cephalotes, they differ quantitatively. The secretion of Acromyrmex octospinosus contains 3-hydoxydecanoic and indoleacetic acids, but lacks phenylacetic acid The bactericidal and fungicidal actions of the three major substances have been confirmed.
