- Design and production of environmentally degradable quaternary ammonium salts
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Quaternary ammonium compounds (QACs) are a class of cationic surfactants routinely used for the disinfection of industries, institutions and households, and have seen a sharp increase in use during the COVID-19 pandemic. However, current commercial QACs consist of only stable chemical bonds such as C-N, C-C, and C-H, which makes their natural degradation rather difficult. Recent studies suggest that emerging negative environmental impacts, such as systemic antibiotics resistance and toxicity to living organisms, are directly associated with prolonged exposure to QACs. Here we report a new class of QAC which contains relatively volatile chemical functional groups such as ester and thioether bonds. Degradation kinetics in aqueous solutions suggests that the stability of these QACs depends not only on their intrinsic hydrophobicity but also on external environmental factors such as pH, temperature and ion presence. The microbicidal effects of QACs containing carbon chains with various lengths were also tested, one of which, named Ephemora , is highly active against a broad spectrum of microbes including fungi, bacteria and viruses, for instance, methicillin-resistant Staphylococcus aureus (MRSA). The easy synthesis and purification of Ephemora starting from inexpensive commercially available reagents, together with its excellent antimicrobial activity and ability to degrade in natural waters over time, make its large-scale commercial production possible.
- Jia, Hengmin,Kong, Hongtao,Ma, Xiuxia,Miao, Hui,Mu, Yan,Zhang, Guoqing,Zhang, Xiaolong,Zhang, Xuepeng
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supporting information
p. 6548 - 6554
(2021/09/10)
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- Cleaner enzymatic production of biodiesel with easy separation procedures triggered by a biocompatible hydrophilic ionic liquid
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The great challenges of modern industry and the environment make it important to develop sustainable energy resources with low cost. In this work, a cleaner enzymatic procedure for biodiesel production was developed through the utilization of a biocompatible and hydrophilic ionic liquid [Choline][H2PO4]. This ionic liquid can be synthesized from cheap raw materials through simple neutralization procedures, and it has been proved to be well biocompatible. The utilization of this ionic liquid in Novozym 435 catalyzed biodiesel production makes the reaction and work-up procedures very simple, because its hydrophilicity can lead to the implementation of a pseudo homogeneous reaction and then heterogeneous separation. Various oil resources such as triolein, sunflower oil and castor oil can all be converted to biodiesels with high yields. After the completion of reaction, both the ionic liquid and Novozym 435 can be recycled and reutilized for at least five cycles without a significant activity decrease. In addition, this reaction system can be conveniently scaled up to the multi-gram level with high efficiency and feasible separation. Overall, the above mentioned benefits make this ionic liquid based enzymatic system cleaner for the production of biodiesel and promising for further industrial applications.
- Chen, Qianhan,Cheng, Shuang,Fan, Dongshuang,Feng, Wanlu,Guo, Yuanyang,Li, Lingjun,Li, Zhiyong,Wang, Jianji,Zhu, Anlian
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p. 1944 - 1951
(2020/04/09)
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- Enzyme-responsive sulfatocyclodextrin/prodrug supramolecular assembly for controlled release of anti-cancer drug chlorambucil
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Supramolecular drug delivery systems are becoming an increasingly important part in controlled drug release. In this work, we report a novel enzyme-responsive supramolecular assembly directly constructed using biocompatible sulfato-β-cyclodextrin (SCD) and an anti-cancer prodrug, i.e. choline modified anti-cancer drug chlorambucil (QA-Cbl). The supramolecular assembly acts as an effective drug delivery system via the controlled drug loading and enzyme-responsive drug release, because the butyrylcholinesterase (BChE) can cleave the ester bond of QA-Cbl prodrug, resulting in the release of anti-cancer drug chlorambucil (Cbl). Compared to other sophisticated drug delivery systems, the present system provides a feasible and functional approach for achievement of controlled drug release.
- Guan, Xinran,Chen, Yong,Wu, Xuan,Li, Peiyu,Liu, Yu
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supporting information
p. 953 - 956
(2019/01/24)
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- Highly luminescent and multi-sensing aggregates co-assembled from Eu-containing polyoxometalate and an enzyme-responsive surfactant in water
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Hybrid co-assembly of polyoxometalates (POMs) with cationic organic matrices offers a preferable way to greatly enhance POM functionality as well as processability. Thus, multi-stimulus responsive supramolecular materials based on lanthanide-containing POMs with improved luminescence may be fabricated from appropriate components through this convenient strategy. Herein, we reported that the co-assembly of Na9(EuW10O36)·32H2O (EuW10) and a commercially available cationic surfactant, myristoylcholine chloride (Myr), in water could produce enhanced red-emitting luminescent aggregates, with their photophysical properties highly dependent on the molar ratio (R) between Myr and EuW10. The R of 36 was finally selected owing to the displayed superior luminescence intensity and good aggregate stability. The Myr/EuW10 hybrids induced by electrostatic and hydrophobic forces presented practically as multilamellar spheres with diameters varying from 80 to 300 nm. Compared to an aqueous solution of EuW10 nanoclusters, a 12-fold increase in absolute luminescence quantum yield (～23.3%) was observed for the hybrid spheres, which was ascribed to the efficient shielding of water molecules. An unusual aggregation arrangement mechanism and the excellent photophysical properties of these aggregates were thoroughly investigated. Both the enzyme substrate character of Myr and the sensitive coordination structure of EuW10 to the surrounding environment made Myr/EuW10 aggregates exhibit multi-stimulus responsiveness to enzymes, pH, and transition metal ions, thus providing potential applications in fluorescence sensing, targeted-release, and optoelectronics.
- Lei, Nana,Shen, Dazhong,Chen, Xiao
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p. 399 - 407
(2019/01/24)
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- IONIC LIQUID AND METHOD FOR DISSOLVING CELLULOSE USING THE SAME
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The present invention provides an ionic liquid represented by the following chemical formula, [(CH3)3N(CH2)2OH]+[NH2(CH2)3CH(NH2)COO]?. The present invention provides an ionic liquid capable of dissolving cellulose within twenty-four hours.
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Paragraph 0019; 0029; 0030
(2018/04/26)
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- POLYMER AND CONTRAST AGENT FOR PHOTOACOUSTIC IMAGING INCLUDING THE POLYMER
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To provide a polymer having a high ratio of the amount thereof present in a tumor to the amount thereof present in blood (hereinafter, sometimes abbreviated as a tumor/blood ratio). The polymer has phosphorylcholine (derivative) as a side chain and has a dye (near-infrared dye) having absorption in the near-infrared wavelength region bound to the polymer.
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Page/Page column 36
(2016/05/24)
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- Catalytic coupling of epoxides and CO2 to cyclic carbonates by carbon nanotube-supported quaternary ammonium salts
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Quaternary ammonium chlorides bound to multi-walled carbon nanotubes as a catalyst for coupling of CO2 and epoxides to produce cyclic carbonates were explored. Reaction variables such as the epoxide structure, the length of alkyl substituents in the quaternary ammonium salts and the spacer chain on the catalytic performance were discussed. The yield of the cyclic carbonates varied between 7 and 89% after 6 h at 110 °C under low pressure (2 MPa of CO2). The epoxide:catalyst mass ratio was 20-30, while 1 mmol g-1 of the quaternary salt was grafted on the carbon nanotubes. A synergy between carboxyl moiety and ammonium moiety grafted on carbon nanotubes was found, and a strong impact of the length of the spacer group used for grafting of the quaternary ammonium salt on nanotubes was observed. The best performance was achieved with short (2 carbon atoms) and long (10 atoms) spacer groups, while a middle-sized spacer group (6 atoms) was not suitable. The length of the alkyl chain of the substituents of the ammonium salt (head group) had a low impact where ethyl and methyl groups performed better than butyl. The reactivity of epoxides was as follows: epichlorohydrin > propylene oxide > styrene oxide. Observations were rationalized by a mechanism where Br?nsted's sites on the surface of nanotubes play an important role during carboxylation of epoxides. The catalyst can easily be separated by filtration recycled without a significant decrease in the catalytic activity if dried properly between the runs.
- Baj, Stefan,Krawczyk, Tomasz,Jasiak, Katarzyna,Siewniak, Agnieszka,Pawlyta, Miros?awa
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- A label-free silicon quantum dots-based photoluminescence sensor for ultrasensitive detection of pesticides
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Sensitive, rapid, and simple detection methods for the screening of extensively used organophosphorus pesticides and highly toxic nerve agents are in urgent demand. A novel label-free silicon quantum dots (SiQDs)-based sensor was designed for ultrasensitive detection of pesticides. This sensing strategy involves the reaction of acetylcholine chloride (ACh) with acetylcholinesterase (AChE) to form choline that is in turn catalytically oxidized by choline oxidase (ChOx) to produce betaine and H2O2 which can quench the photoluminescence (PL) of SiQDs. Upon the addition of pesticides, the activity of AChE is inhibited, leading to the decrease of the generated H 2O2, and hence the PL of SiQDs increases. By measuring the increase in SiQDs PL, the inhibition efficiency of pesticide to AChE activity was evaluated. It was found that the inhibition efficiency was linearly dependent on the logarithm of the pesticides concentration. Consequently, pesticides, such as carbaryl, parathion, diazinon, and phorate, were determined with the SiQDs PL sensing method. The lowest detectable concentrations for carbaryl, parathion, diazinon, and phorate reached 7.25 × 10-9, 3.25 × 10-8, 6.76 × 10-8, and 1.9 × 10-7 g/L, respectively, which were much lower than those previously reported. The detecting results of pesticide residues in food samples via this method agree well with those from high-performance liquid chromatography. The simple strategy reported here should be suitable for on-site pesticides detection, especially in combination with other portable platforms.
- Yi, Yinhui,Zhu, Gangbing,Liu, Chang,Huang, Yan,Zhang, Youyu,Li, Haitao,Zhao, Jiangna,Yao, Shouzhuo
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p. 11464 - 11470
(2014/01/06)
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- A novel approach for synthesis of 3-amino-5-aryl-2,5-dihydropyridazines using onium salt as soluble support
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In this work it was presented an application of task specific onium salt as soluble support for the synthesis of 3-amino-5-aryl-2,5-dihydropyridazines. This soluble support is of wide applicability and combines advantages of solid phase synthesis without its limitations with those of solution phase chemistry. After a simple washing step, products were cleaved from the supports and obtained in good yields.
- Gao, Meng,Lu, Cui Fen,Yang, Gui Chun,Chen, Zu Xing
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experimental part
p. 823 - 826
(2012/01/05)
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- Task specific onium salt as soluble support in multicomponent synthesis of 4-aryl-2-amino-3-ethoxycarbonyl-naphthopyrans
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In this paper was presented an application of task specific onium salt as soluble support in multicomponent synthesis of 2-amino-3-ethoxycarbonyl- naphthopyrans. The starting task-specific onium salt was functionalized in good yield with chloroethyl alcohol, followed by three steps containing esterification, three components reaction and cleavage from onium salt to afford naphthopyrans in 60% -88% overall yields. All of the products were characterized by IR, 1H NMR, 13C NMR and MS techniques. In this paper was presented an application of task specific onium salt as soluble support in multicomponent synthesis of 2-amino-3-ethoxycarbonyl-naphthopyrans. The starting task-specific onium salt was functionalized in good yield with chloroethyl alcohol, followed by three steps containing esterification, three components reaction and cleavage from onium salt to afford naphthopyrans in 60%-88% overall yields. All of the products were characterized by IR, 1H NMR, 13C NMR and MS techniques.
- Lu, Cuifen,Zhang, Li,Yang, Guichun,Chen, Zuxing
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experimental part
p. 2469 - 2473
(2011/10/02)
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- DNA encoding human κ casein and process for obtaining the protein
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The present invention relates to an expression system comprising a DNA sequence encoding a polypeptide which has a biological activity of human κ-casein, the system comprising a 5′-flanking sequence capable of mediating expression of said DNA sequence. In preferred embodiments the 5′-flanking sequence is from a milk protein gene of a mammal such as a casein gene or whey acidic protein (WAP) gene and the DNA sequence contains at least one intron sequence selected from the intron sequences presented in SEQ ID NO:30. The invention also relates to DNA sequences, replicable expression vectors and cells harboring said vectors, recombinant polypeptide e.g. in glycosylated form, and milk, infant formula or nutrient supplement comprising recombinant polypeptide. The invention further relates to a transgenic non-human mammal such as a mouse, rat, rabbit, goat, sheep, pig, lama, camel or bovine species whose germ cells and somatic cells contain a DNA sequence as defined above as a result of chromosomal incorporation into the non-human mammalian genome, or into the genome of an ancestor of said non-human mammal.
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- Preparation of solutions of betaine
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Betaine is produced by the oxidation of a choline salt in the presence of a base and a supported noble metal catalyst at temperatures from about 20 DEG C. to 100 DEG C. and pressures from atmospheric to about 100 psi. This process is advantageous over prior processes for the production of betaine in that no amine halocarboxylate contaminants are produced by this reaction.
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- THERMOCHEMISTRY OF THE SYNTHESIS OF CHOLINE CHLORIDE
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Heat effects of the synthesis of choline chloride and of a series homogeneous and heterogeneous processes involved were determined by the microcalorimetric method. Data obtained enabled us to determine the standard enthalpy of formation of choline chloride and the enthalpy of its formation in the reaction mixture.
- Miroshnichenko, E. A.,Vorob'eva, V. P.,Mizina, N. A.,Tereshchenko, G. F.,Korchatova, L. I.
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p. 1648 - 1649
(2007/10/02)
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- Parallel mechanisms in acetylcholinesterase-catalyzed hydrolysis of choline esters
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The mechanisms of acetylcholinesterase (AChE)-catalyzed hydrolyses of four choline esters, (acetylthio)-choline, (propanoylthio)choline, (butanoylthio)choline, and benzoylcholine, have been compared by measuring relative activities and pH-rate effects. The reactivity of Electrophorus electricus AChE toward these substrates decreases in the above order and spans a 1500-fold range of kcat and a 2300-fold range of kcat/Km. The pH-V/K profile for (acetylthio)choline hydrolysis shows that activity depends on the basic form of an active site residue, probably H440, that has a pKa = 6.22 ± 0.03 (Rao, M.; et al. J. Am. Chem. Soc. 1993, 115, in press; ref 23). The pH-V/K profile for (propanoylthio)choline shows similar behavior and gives a pKa = 6.42 ± 0.03. The pH-V/K profile for (butanoylthio)-choline hydrolysis, on the other hand, shows that activity depends on the basic forms of three active site residues, two that have pKa values of 4.72 ± 0.02 and one that has a pKa value of 6.3 ± 0.1. For the least reactive substrate, benzoylcholine, pH-V and pH-V/K profiles depend only on the ionizations of the residues that have the lower pKa values, 4.77 ± 0.03 and 4.71 ± 0.03, respectively. The solvent isotope effects for benzoylcholine hydrolysis are DV/K = 1.91 ± 0.06 and DV = 1.7 ± 0.3, and proton inventories of these parameters suggest that a carboxylate residue functions as a general base catalyst. Torpedo californica AChE also displays a high kinetic discrimination for (acetylthio)-choline versus (butanoylthio)choline; the ratio of kcat values for the respective substrates is 3800, while the corresponding kcat/Km ratio is 850. The pH-V/K profile for hydrolysis of (acetylthio)choline depends on a single residue that has pKa = 6.33 ± 0.03, while that for hydrolysis of (butanoylthio)choline has a maximum at pH ～5.5 and depends on amino acid residues that have pKa values of 4.99 ± 0.07 and 6.1 ± 0.3. Therefore, parallel mechanisms operate in acetylcholinesterase-catalyzed hydrolysis of choline esters. The biomimetic substrate (acetylthio)choline and the homologue (propanoylthio)choline are hydrolyzed via nucleophilic and general acid-base catalysis by the active site triad S200-H440-E327. As the substrate reactivity decreases, the mechanism shifts progressively from triad catalysis to one that likely involves general base catalysis by E199 of direct water attack on the scissile carbonyl. Molecular modeling suggests that the sterically circumscribed acyl-binding site accommodates the acetyl and propanoyl functions of choline substrates. However, the sterically encumbered butanoyl and benzoyl functions are less well accommodated in the acyl-binding site, and thus the corresponding substrates apparently occupy an alternate binding site in the active site gorge from which catalysis by E199 is effected.
- Selwood, Trevor,Feaster, Shawn R.,States, Michael J.,Pryor, Alton N.,Quinn, Daniel M.
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p. 10477 - 10482
(2007/10/02)
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- Method of making boron analogues
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A method of synthesizing boron analogues of choline and choline related mrials is disclosed. The method comprises reacting N,N dimethylethanolamine with hydrogen chloride or an acid chloride to form an ester hydrochloride. The resulting aminoalcohol hydrochloride or ester hydrochloride is further reacted with tetraethyl NBH4. Also disclosed are pharamaceutically interesting compounds of acetylcholine.
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- Multiple Forms and Some Properties of Alkaline Phosphatase Produced by Aspergillus oryzae on Solid Medium
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Three forms of alkaline phosphatase (Al-PMase) (EC. 3.1.3.1) were partially purified from Aspergillus oryzae grown on a bread medium which was in a phosphate-restricted condition.The purified enzymes were named Al-PMase I, II, and III, with pH optima at about pH 8.9 ca. 9.5, and 10, respectively.Al-PMase II seem to be a major component un the Al-PMases of this fungus.The enzymes were satisfactorily stable at pH 7 to 10 at 30 deg C.Al-PMase I, II, and III were subjected to competitive inhibition with phosphate and commonly inhibited with Hg(2+) and Mn(2+).Al-PMase I and II were inhibited completely with EDTA, but Al-PMase II was insensitive to EDTA.Al-PMase II and III seemed to be a non-specific alkaline phosphatase.Al-PMase I showed less affinity to 5'-nucleic acids than 2'(3')-nucleic acids, and did not hydrolyze α-naphthyl phosphate, α-glycerophosphate, O-phosphoethanolamine, and phosphorylcholine.
- Sakurai, Yonekichi,Toda, Katsuyoshi,Shiota, Hideo
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p. 1959 - 1968
(2007/10/02)
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