- Lipase-catalyzed synthesis of sucrose monolaurate and its antibacterial property and mode of action against four pathogenic bacteria
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The aim of this work was to evaluate the antibacterial activities and mode of action of sucrose monolaurate (SML) with a desirable purity, synthesized by Lipozyme TL IM-mediated transesterification in the novel ionic liquid, against four pathogenic bacteria including L. monocytogenes, B. subtilis, S. aureus, and E. coli. The antibacterial activity was determined by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and the time–kill assay. SML showed varying antibacterial activity against tested bacteria with MICs and MBCs of 2.5 and 20 mM for L. monocytogenes, 2.5 and 20 mM for B. subtilis, 10 and 40 mM for S. aureus, respectively. No dramatic inhibition was observed for E. coli at 80 mM SML. Mechanism of bacterial inactivation caused by SML was revealed through comprehensive factors including cell morphology, cellular lysis, membrane permeability, K+ leakage, zeta potential, intracellular enzyme, and DNA assay. Results demonstrated that bacterial inactivation against Gram-positive bacteria was primarily induced by the pronounced damage to the cell membrane integrity. SML may interact with cytoplasmic membrane to disturb the regulation system of peptidoglycan hydrolase activities to degrade the peptidoglycan layer and form a hole in the layer. Then, the inside cytoplasmic membrane was blown out due to turgor pressure and the cytoplasmic materials inside leaked out. Leakage of intracellular enzyme to the supernatants implied that the cell membrane permeability was compromised. Consequently, the release of K+ from the cytosol lead to the alterations of the zeta potential of cells, which would disturb the subcellular localization of some proteins, and thereby causing bacterial inactivation. Moreover, remarkable interaction with DNA was also observed. SML at sub-MIC inhibited biofilm formation by these bacteria.
- Shao, Shi-Yin,Shi, Yu-Gang,Wu, Yu,Bian, Li-Qing,Zhu, Yun-Jie,Huang, Xin-Ying,Pan, Ying,Zeng, Lu-Yao,Zhang, Run-Run
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- Effect of Variations in the Fatty Acid Residue of Lactose Monoesters on Their Emulsifying Properties and Biological Activities
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Lactose fatty acid esters are high-value-added derivatives of lactose and represent a class of biodegradable, non-ionic, low-molecular-weight surfactants (emulsifiers) that have considerable potential in the food, cosmetic, and pharmaceutical industries. Certain lactose esters have also garnered attention for their biological activities. In this work, we detail syntheses of a homologous series of 6′-O-acyllactose esters of varying alkyl chain length (from 6 to 18 carbons) and report on their activities as surfactants as well as their antimicrobial and cytotoxic properties. The structure-property profiles established in this work revealed that while the medium-chain esters displayed excellent emulsifying properties and moderate antimicrobial activities, their longer chain congeners exhibited the highest cytotoxicities. As such, we have established that certain 6′-O-acyllactose esters are superior to their sucrose-derived and commercially exploited counterparts. These results will serve as a useful guide for the development of lactose esters as, inter alia, emulsifiers in the food industry.
- Liang, Min-Yi,Banwell, Martin G.,Wang, Yong,Lan, Ping
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- Regioselective synthesis of sucrose monoesters as surfactants
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A highly regioselective conversion of sucrose into 6-O-acyl derivatives is reported. First sucrose was transformed into the dibutyltin acetal, thus enhancing the nucleophilicity at the C-6 oxygen and restricting the subsequent acylation reaction. The surface activity properties of the sucrose monoesters obtained were determined and compared with those of commercially available ionic and non-ionic surfactants.
- Vlahov, Iontcho R.,Vlahova, Petinka I.,Linhardt, Robert J.
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- Catalytic selective synthesis method of mono-fatty acid oligosaccharide ester
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The invention discloses a catalytic selective synthesis method of mono-fatty acid oligosaccharide ester. The method comprises the following steps: adding oligosaccharide, fatty acid or fatty acid ester and a mesoporous catalyst into a reaction solvent, and carrying out mixed reaction; and carrying out filtering, concentrating, recrystallizing and drying to obtain the mono-fatty acid oligosaccharide ester. A multi-phase confinement catalytic selective conversion strategy is adopted, and a series of mono-fatty acid oligosaccharide esters is directly synthesized by appropriately adjusting the acidity or alkalinity and accurately controlling matching of a pore structure and a mono-fatty acid oligosaccharide ester structure, so that the purity and yield are high; and the reaction process is efficient and clean, the refining and purifying process is easy and convenient to operate, energy-saving and environment-friendly, the mesoporous catalyst can be recycled, the performance is kept, the method is suitable for large-scale production, and the toxic residue risk of organic (metal) catalysis and the high cost of biological enzyme catalysis are avoided.
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Paragraph 0037-0040
(2020/06/17)
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- Appearance and distribution of regioisomers in metallo- and serine-protease-catalysed acylation of sucrose in N,N-dimethylformamide
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The appearance and distribution of monoester regioisomers were investigated in the virtually irreversible acylation of sucrose with the enol ester, vinyl laurate, as acyl donor catalysed by serine proteases and a metalloprotease in the hydrophilic, aprotic solvent N,N-dimethylformamide. Sucrose laurate was obtained in yields from 12 to 53% after 48 h under different catalytic conditions. The serine protease ALP-901, derived from a Streptomyces sp., produced the highest yield at this reaction time, while reaction with the zinc-protease thermolysin achieved the overall highest yield (63%) after 6 h, with only monoesters synthesised. The total conversion of sucrose after 48 h ranged from 19 to 96%. The highest degree of conversion was observed in the reaction with thermolysin, while the reactions without protein and with ALP-901 resulted in 82% and 66% sucrose conversion, respectively. 2-O-Lauroyl sucrose was the most abundant monoester regioisomer synthesised and the highest concentration observed was 23.7 mM after 24 h in the thermolysin-catalysed reaction. The highest concentration of 2-O-lauroyl sucrose detected in the reaction catalysed by ALP-901 was 19.0 mM, while it was 17.0 mM the reaction without protein, both after 48 h. The detected appearance of the sucrose laurate regioisomers largely corresponded to the apparent rates of formation, and 2-O-lauroyl sucrose was among the first regioisomers to appear in all reactions. The observed sucrose laurate regioisomeric distribution after 48 h (2:3:4:6:1′:3′) was 72:5:2:1:7:14 in the reaction catalysed by ALP-901, and 74:5:2:1:7:13 in the reaction without protein. In the reaction catalysed by thermolysin the distribution was 71:5:2:-:9:13 after 6 h and 86:8:-:-:4:3 after 48 h of reaction. The esterification of sucrose with vinyl laurate without protein in the reaction mixture appeared to be catalysed in the presence of aluminosilicate molecular sieves. Non-catalytic protein in the reaction medium seemed to lower the catalytic activity of the molecular sieves.
- Lie, Aleksander,Meyer, Anne S.,Pedersen, Lars Haastrup
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- SYNTHESIS AND ACTIVITY OF LACTOSE ESTERS
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This disclosure provides for a novel lactose monolaurate (LML) with the structure useful as an antimicrobial agent and as a potential substitute for other sugar esters. Methods of synthesizing LML using immobilize lipases and various solvents are also provided.
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Page/Page column 2-3
(2011/10/31)
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- Improved synthesis of sucrose fatty acid monoesters under ultrasonic irradiation
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Sucrose fatty acid esters were synthesized by the transesterification of sucrose with aliphatic esters under ultrasound irradiation in good yield (≥73%). The optimum reaction conditions for the transesterification reaction include a molar ratio of sucrose to fatty acid ethyl ester of 2:1 and the use of a 13% mol anhydrous K2CO3 catalyst. The optimum reaction temperature was set at 70 °C, the optimum reaction time was 2 h, and the optimum reaction pressure was 11 kPa. The reaction had excellent monoester selectivity. The proportion of monoester (6-monoester + 6′-monoester) in the purified products was up to 92-95% via flash column chromatography over silica gel, the ratios of 6-monoester/6′-monoester are 2.1-2.7, and the sucrose monoesters were identified by HPLC-MS, NMR and IR.
- Huang, Dan,Jiang, Xue,Zhu, Hao,Fu, Xiaorong,Zhong, Kangrong,Gao, Weidong
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experimental part
p. 352 - 355
(2010/12/25)
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- Tin Mediated Regioselective Synthesis of Sucrose-6-Esters
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A method is disclosed for regioselective synthesis of sucrose-6-acetate via formation of a novel sucrose-tin adduct using sucrose and DBTO. The novel tin adduct can be represented by a formula (6-O-sucrose)-O—Snbutyl2-O-(6-O-sucrose) or as 1,3.(di O-sucrose) dibutyl stannylene. The adduct is acylated to yield sucrose-6-acetate or sucrose-6-benzoate as major product.
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Page/Page column 4
(2009/05/29)
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- Regioselective formation of 6-O-acylsucroses and 6,3′-di-O-acylsucroses via the stannylene acetal method
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Regioselective formation of 6-O-acylsucroses and 6,3′-di-O-acylsucroses in one pot with good yields was achieved for the first time by a typical acylation method of sucrose via its dibutylstannylene acetal. Pure monoesters at OH-6 and diesters at OH-6,3′ obtained by these procedures were readily isolated by simple column chromatography, thus overcoming the main difficulties associated with regioselectivity, efficiency, and isolation techniques for the practical preparation. Explanations for the regioselectivities observed during this stannylene acetal-mediated reaction were also proposed based on the structures of the stannylene acetal in solution and the intramolecular migration of stannylenes.
- Wang, Qinghui,Zhang, Shufen,Yang, Jinzong
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p. 2657 - 2663
(2008/09/17)
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- Shape dependence in the formation of condensed phases exhibited by disubstituted sucrose esters
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We report on the self-organizing properties of sucrose esters that are di-(1′,6′, 1′,6, and 6,6′)-substituted with aliphatic chains of identical or different chain lengths and levels of saturation. For the materials possessing two saturated aliphatic chains, the compounds exhibited thermotropic lamellar smectic A phases. A remarkable new phase transition was observed for the di-octadecanoyl homologue in which one smectic A phase transformed into another with a continuous change in layer spacing, but with a discontinuous change in the correlation length. The incorporation of long cis-unsaturated chains led to increased cross-sectional areas of the chains relative to the sucrose head groups and, hence, columnar phases were observed.
- Molinier, Valerie,Kouwer, Paul J. J.,Fitremann, Juliette,Bouchu, Alain,Mackenzie, Grahame,Queneau, Yves,Goodby, John W.
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p. 1763 - 1775
(2008/02/04)
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- Self-organizing properties of monosubstituted sucrose fatty acid esters: The effects of chain length and unsaturation
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Three families of mono-substituted sucrose fatty acid esters were prepared by enzymatic and classical synthetic procedures, and their self-assembly and self-organizational properties were investigated by thermal polarised light microscopy, differential scanning calorimetry and X-ray diffraction. The properties were evaluated as a function of the fatty acid chain length. For the lower homologues of the series columnar liquid-crystalline stacking structures were found, whereas for the higher homologues, lamellar phases predominated. A model for the columnar stacking arrangement, consisting of a unique arrangement of the molecules which could lead to the creation of multiple internal ion channels between the hydrophobic interior and the hydrophilic exterior of the columns, is suggested.
- Molinier, Valerie,Kouwer, Paul J. J.,Fitremann, Juliette,Bouchu, Alain,Mackenzie, Grahame,Queneau, Yves,Goodby, John W.
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p. 3547 - 3557
(2008/02/04)
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- Sucrose esterification under Mitsunobu conditions: Evidence for the formation of 6-O-acyl-3′,6′-anhydrosucrose besides mono and diesters of fatty acids
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A series of sucrose monoesters and homogeneous or mixed diesters, which have various chain lengths and saturation levels, were prepared under Mitsunobu conditions with good regioselectivity. Among the anhydro derivatives arising from competitive intramolecular etherification, 3′,6′-anhydrosucrose 6-O-monoesters, which have never been reported, were identified.
- Molinier, Valerie,Fitremann, Juliette,Bouchu, Alain,Queneau, Yves
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p. 1753 - 1762
(2007/10/03)
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- Synthesis of sucrose laurate using a new alkaline protease
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Sucrose laurate esters were synthesized from sucrose and vinyl laurate in organic solvents using an alkaline protease from a new alkalophilic strain, Bacillus pseudofirmus AL-89. Maximum synthetic activity was observed in the presence of 7.5% v/v water and in the pH range of 7-10. With protease AL-89 esterification occurred predominantly at the 2-O-position while subtilisin A-catalyzed monoester formation predominantly at the 1′-O position. In the absence of enzyme, buffer salts catalyzed non-specific reactions, resulting in the formation of a number of esters. Non-specific catalysis was also observed upon inhibition of the enzyme using a serine protease inhibitor or upon deactivation of the enzyme at pH above 10.
- Pedersen, Ninfa Rangel,Wimmer, Reinhard,Matthiesen, Rune,Pedersen, Lars Haastrup,Gessesse, Amare
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p. 667 - 673
(2007/10/03)
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- Transesterification of Sucrose in Organic Medium: Study of Acyl Group Migrations
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The tendency of the acyl groups located on the glucose part of sucrose fatty acid esters to undergo intramolecular migrations in organic medium and the regioselectivity of some transesterifications of sucrose were investigated by HPLC, in situ NMR spectroscopy and preparative methods. Extensive acylation on secondary positions of the glucose moiety followed by migrations is general for base catalysed transesterification. The stability of 3- and 6-O-acyl derivatives, two isomers being thermodynamically favored compared to others, was studied in a series of conditions. It is shown that the presence of water catalyzes the migration of the ester at OH-3 towards OH-6 in organic basic medium, whereas the ester at OH-6 appears more stable under either acidic or basic conditions.
- Molinier, Valerie,Wisniewski, Krzysztof,Bouchu, Alain,Fitremann, Juliette,Queneau, Yves
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p. 657 - 669
(2007/10/03)
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- Proteinase N-catalysed regioselective esterification of sucrose and other mono- and disaccharides
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Crude Proteinase N was used as catalyst for the synthesis of carbohydrate (in particular sucrose) esters by transesterification of activated esters in organic solvents. Polymerisable or amphiphilic sucrose esters (methacrylates and laurates) were obtained
- Potier, Pierre,Bouchu, Alain,Gagnaire, Juliette,Queneau, Yves
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p. 2409 - 2419
(2007/10/03)
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- A new synthesis of 6-O-acylsucroses and of mixed 6,6'-di-O-acylsucroses
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Various 6-O-acylsucroses were synthesized in good yields from unprotected sucrose in N,N-dimethylformamide and the appropriate 3-acylthiazolidine-2-thiones 6 or 3-acyl-5-methyl-1,3,4-thiadiazole-2(3H)-thiones 7.A selective ionization of the free sugar by
- Baczko, Krystyna,Nugier-Chauvin, Caroline,Banoub, Joseph,Thibault, Pierre,Plusquellec, Daniel
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- A new chemoenzymatic synthesis of 6'-O-acylsucroses
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6'-O-acylsucroses were synthesized for the first time in two steps, including a new chemical selective acylation of free sucrose followed by an enzymatic hydrolysis of the 6-O-acylated by-products.
- Chauvin,Plusquellec
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p. 3495 - 3498
(2007/10/02)
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