88973-62-0Relevant academic research and scientific papers
Ether-functionalized ionic liquids for nonaqueous biocatalysis: Effect of different cation cores
Zhao, Hua,Kanpadee, Naphatsawan,Jindarat, Chanida
, p. 104 - 112 (2019/03/28)
Ether-functionalized ionic liquids (ILs) usually have low viscosities, and can be designed to be compatible with enzymes. However, there is a lack of understanding of the effect of different ether-functionalized structures on the enzyme activity. We systematically evaluated new ether-functionalized ILs carrying different cation cores (pairing with Tf2N? anions) in two Novozym 435-catalyzed reactions: (1) the transesterification of ethyl sorbate with 1-propanol at 50 °C; (2) the ring-opening polymerization (ROP) of ε-caprolactone at 70 °C. The lipase showed different activities: in the first reaction, [CH3OCH2CH2-Et3N][Tf2N] and [CH3OCH2CH2-Py][Tf2N] gave the highest reaction rates; in the second reaction, [CH3OCH2CH2-PBu3][Tf2N] produced the highest molecular mass (Mw up to 25,400 Da). The lipase's thermal stability in [CH3OCH2CH2-Et3N][Tf2N] was found much higher than that in t-butanol. The fluorescence spectra of free lipase (excited at 280 nm) in these ILs reveal that the wavelength of the maximum emission peak occurred at 314 nm for both [CH3OCH2CH2PBu3][Tf2N] and [CH3OCH2CH2PEt3][Tf2N], which matched closely with that (313 nm) in aqueous phosphate buffer (pH 7.5, 20 mM), while other ether-functionalized ILs led to various degrees of red shifts. In summary, the lipase activity is not only dependent on the IL structure, but also on the substrate and other reaction conditions.
New eutectic ionic liquids for lipase activation and enzymatic preparation of biodiesel
Zhao, Hua,Baker, Gary A.,Holmes, Shaletha
supporting information; experimental part, p. 1908 - 1916 (2011/04/23)
The enzymatic preparation of biodiesel has been hampered by the lack of suitable solvents with desirable properties such as high lipase compatibility, low cost, low viscosity, high biodegradability, and ease of product separation. Recent interest in using ionic liquids (ILs) as advanced reaction media has led to fast reaction rates and high yields in the enzymatic synthesis of biodiesel. However, conventional (i.e., cation-anion paired) ILs based on imidazolium and other quaternary ammonium salts remain too expensive for wide application at industrial scales. In this study, we report on newly-synthesized eutectic ILs derived from choline acetate or choline chloride coupled with biocompatible hydrogen-bond donors, such as glycerol. These eutectic solvents have favorable properties including low viscosity, high biodegradability, and excellent compatibility with Novozym 435, a commercial immobilized Candida antarctica lipase B. Furthermore, in a model biodiesel synthesis system, we demonstrate high reaction rates for the enzymatic transesterification of Miglyol oil 812 with methanol, catalyzed by Novozym 435 in choline acetate/glycerol (1:1.5 molar ratio). The high conversion (97%) of the triglyceride obtained within 3 h, under optimal conditions, suggests that these novel eutectic solvents warrant further exploration as potential media in the enzymatic production of biodiesel.
The acyl nitroso Diels-Alder (ANDA) reaction of sorbate derivatives: An X-ray and 15N NMR study with an application to amino-acid synthesis
Bollans, Lee,Bacsa, John,Iggo, Jonathan A.,Morris, Gareth A.,Stachulski, Andrew V.
supporting information; experimental part, p. 4531 - 4538 (2009/12/25)
We present a study of the acyl nitroso Diels-Alder (ANDA) reaction of sorbate esters and sorbic alcohol derivatives, using alkoxycarbonyl nitroso dienophiles. An optimisation of the reaction conditions for ethyl sorbate is first presented, and the product is used in an efficient synthesis of 5-methylornithine. Structure-reactivity trends in sorbic alcohol (E,E-2,4-hexadien-1-ol) and its acylated analogues are then discussed. We present single-crystal X-ray structural proof for key adducts in both series and present in detail a novel HMBC/HSQC (1H-15N) criterion for ready distinction of regioisomers arising from such ANDA reactions.
Quantitative structure-activity relationship studies for prediction of antimicrobial activity of synthesized 2,4-hexadienoic acid derivatives
Narasimhan, Balasubramanian,Judge, Vikramjeet,Narang, Rakesh,Ohlan, Ruchita,Ohlan, Sucheta
, p. 5836 - 5845 (2008/03/18)
A new series of 2,4-hexadienoic acid derivatives (S1-S42) has been synthesized and evaluated as antimicrobial agents against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Candida albicans, and Aspergillus niger. Quantitative structure-activity relationship (QSAR) investigation using Hansch analysis was applied to find out correlation between antimicrobial activities with physicochemical properties of the synthesized compounds. Various physicochemical descriptors and experimentally determined minimum inhibitory concentration values for different microorganisms were used as independent and dependent variables, respectively. The QSAR revealed that topological parameters especially molecular connectivity indices (χ2, 0χv, 2χv) were found to have overall significant correlation with antimicrobial activity of 2,4-hexadienoic acid derivatives. The statistical results of training set, cross-validated r2 and conventional r values gave reliability to the prediction of molecules with activity using QSAR models.
Polyenic acids. I. Antifungal and bacteriostatic activities of hexa-2,4 dienoic acid derivatives
Le Baut,Sparfel,Clairc,et al.
, p. 441 - 445 (2007/10/02)
Synthesis of esters and amides of 2,4-(2 E, 4 E) hexadienoic acid are reported. The authors have tried to modulate the polarity of these compounds by introducing sequences with hydroxyl, amino groups, ether, thioether functions and halogen atoms or heterocycles. A gain in bacteriostatic activity, compared with sorbic acid has been stated in some cases, it is accompanied by either a breakdown (compounds 3, 38, 51, and 54) or a maintenance of fungistatic activity (compounds 5, 10 and 17).
