Publications
Enantio-differentiating hydrogenation of alkyl 3-oxobutanoates over tartaric acid-modified Ni catalyst: Enthalpy-entropy compensation effect as a tool for elucidating mechanistic features
Tsutomu Osawaa, Masahiro Wakasugi, Tomoko Kizawa, Victor Borovkov, Yoshihisa Inoue
Molecular Catalysis, 2018, Volume 449, Pages 131–136.
https://doi.org/10.1016/j.mcat.2018.02.023
The enantio-differentiating hydrogenations of a series of alkyl 3-oxobutanoates were carried out at the temperatures ranging from 333 to 393 K over the (R,R)-tartaric acid-modified Ni catalyst prepared from commercially available Ni powder to achieve high enantiomeric excesses of 91-94%. It was demonstrated that the enantio-selectivity was not a simple function of the reaction temperature, being enhanced in the low temperature region to reach a maximum at 363–373 K and then decreased at higher temperatures. Nevertheless, all the differential enthalpies and entropies of activation calculated from the enantiomer ratios in the low and high temperature regions compensated with each other, indicating the same enantio-differentiation mechanism over the entire temperature range. A plausible enantio-differentiation mechanism explaining the effects of hydrogenation temperature on the enantio-selectivity is proposed.
Applications of fungal cellulases in biofuel production: Advances and limitations
Neha Srivastava, Manish Srivastava, P.K. Mishra, Vijai K.Gupta, Gustavo Molina, Susana Rodriguez-Couto, Ambepu Manikanta, P.W. Ramteke
Renewable & Sustainable Energy Reviews, 2018, Volume 82, Part 3, Pages 2379-2386.
https://doi.org/10.1016/j.rser.2017.08.074
Nonrenewable fossil fuels and their serious environmental impact have forced to develop renewable & sustainable energy sources. In this scenario, cellulases have found extensive applications in the biofuel industries. Three main components of the cellulase enzymatic system, namely endoglucanase, exoglucanase and β-glycosidase, effectively convert cellulosic substrates into fermentable sugars. The commercial production of cellulase is currently performed under submerged fermentation (SmF) conditions using mesophilic microbial strains which are non-economic and also non-sustainable. Although, production of fungal cellulases using solid-state fermentation (SSF) is economically advantageous and a preferable route for industrial purposes, it suffers from a few bottlenecks (e.g. scale-up, difficult to control process parameters). Therefore, the present review provides an overview of the cost-effective and present scenario of cellulase production in the biofuel industries including recent advancements. In addition, the current limitations hampering the cost-effective production of cellulase have also been discussed to resolve them in the near future.
Helicene-Based Chiral Auxiliaries and Chirogenesis
Mohammed Hasan and Victor Borovkov
Symmetry, 2018, 10 (1), 10
DOI: 10.3390/sym10010010
Helicenes are unique helical chromophores possessing advanced and well-controlled spectral and chemical properties owing to their diverse functionalization and defined structures. Specific modification of these molecules by introducing aromatic rings of differing nature and different functional groups results in special chiroptical properties, making them effective chiral auxiliaries and supramolecular chirogenic hosts. This review aims to highlight these distinct structural features of helicenes; the different synthetic and supramolecular approaches responsible for their efficient chirality control; and their employment in the chirogenic systems, which are still not fully explored. It further covers the limitation, scope, and future prospects of helicene chromophores in chiral chemistry.
Green profiling of aprotic versus protic ionic liquids: Synthesis and microbial toxicity of analogous structures
Joshua E.S.J. Reid, Hannah Prydderch, Marcel Spulak, Seishi Shimizu, Adam J. Walker, Nicholas Gathergood
Sustainable Chemistry and Pharmacy, Volume 7, March 2018, Pages 17–26.
https://doi.org/10.1016/j.scp.2017.11.001
How does the variation in the ionic nature of ionic liquids (ILs) affect their antimicrobial properties? To answer this question with a direct connection to the molecular structure of ILs is integral for the design of new task specific ILs. The effect of ionic nature can be investigated through a comparison between analogous aprotic and protic ILs. However, while there have been extensive studies on the toxicology of both aprotic and protic ILs, the number of different structures and procedures employed makes quantitative comparison impossible. To address this, a series of analogous N,N,N-trimethylethanolammonium (cholinium) derived aprotic ILs (AILs) and N,N-dimethylethanolammonium derived protic ILs (PILs) with acetate, hexanoate, d,l-mandelate and 3-ethoxypropionate anions were prepared and characterised. All ILs were subsequently screened for antimicrobial activity against eight bacterial and twelve fungi strains. From the antimicrobial activity screening, little difference was found between the toxicities of AILs and PILs with shorter chains terminating in hydroxyl functional groups (e.g cholinium hexanoate and N,N-dimethylethanolammonium hexanoate). Variations between anion structure demonstrated slightly higher toxicities for more lipophilic anions. Antimicrobial activities were found to significantly increase for ILs with a long ether chain functional groups in the cation, due to the enhanced surfactant properties of these long chain cations. The importance of toxicity screening of analogous series of AILs and PILs as part of a future comprehensive biodegradation analysis has also been proposed based on postulated IL breakdown pathways.
Highly sensitive conformational switching of ethane-bridged mono-zinc bis-porphyrin as an application tool for rapid monitoring of aqueous ammonia and acetone
Buccolieri A., Manno D., Serra A., Santino A., Hasan M., Borovkov V., Giancane G.
Sensor Actuat. B-Chem., 2018, 257, 685-691.
https://doi.org/10.1016/j.snb.2017.11.021
The spectroscopic behavior of mono-zinc ethane-bridged bis-porphyrin (ZnH2Po2) was studied as a solid film upon deposition from a chloroform solution by means of the spin-coating method. The angular speed used during the deposition strongly influences the conformational arrangement of bis-porphyrin. A preferential arrangement as the anti- (opened) conformer was obtained when high speeds were used. The obtained thin film was successfully employed to detect ammonia and acetone as the relevant analytes in aqueous solutions. This was a result of the supramolecular interaction between each of these two compounds used and the bis-porphyrin active layer, inducing the corresponding conformational switching easily detectable by UV–vis absorption spectroscopy. The spectral variations of ZnH2Po2 were evident in the range of concentrations between 1 ppm and 20 ppm for both the analytes. This is particular important in light of the fact that ammonia and acetone concentrations are changed within this limit throughout the menstrual women’s cycle, reaching their maximum during the fertility days. Hence, ZnH2Po2 can be effectively applied as a potential active layer for medical devices to monitor the hormonal variations during the women’s menstrual cycle.
Enantioselective one-pot synthesis of α,β-epoxy ketones via aerobic oxidation of cyclopropanols
Elek G.Z., Borovkov V., Lopp M., Kananovich D.G.
Org. Lett., 2017, 19, 3544-3547
dx.doi.org/10.1021/acs.orglett.7b01519
An efficient, mild, and environmentally benign method was developed for the asymmetric synthesis of 2-oxyranyl ketones from easily available tertiary cyclopropanols. The one-pot protocol includes the aerobic oxidation of cyclopropanol derivatives catalyzed by Mn(III) complexes followed by the poly-l-leucine-assisted stereoselective elimination of water from the intermediate peroxides with DBU to afford the corresponding epoxy ketones in high yields and good-to-excellent enantioselectivities (up to 97%).
Preparation of stereochemically pure E- and Z-alkenoic acids and their methyl esters from bicyclo[n.1.0]alkan-1-ols. Application in the synthesis of insect pheromones
Zubrytski, D. M.; Kananovich, D. G.; Matiushenkov, E. A.
Russ. J. Org. Chem. 2017, 53, 813-823.
https://doi.org/10.1134/S107042801706001X
Oxidative cleavage of exo- and endo-alkyl- and hydroxyalkyl-substituted bicyclo[n.1.0]alkan-1-ols with (diacetoxy-λ3-iodanyl)benzene gave the corresponding methyl alkenoates exclusively with E or Z configuration of the double bond. This reaction was used as the key stage in the syntheses of stereoisomerically pure components of pest insect pheromones: (E)-dodec-9-en-1-yl acetate (European pine shoot moth Rhyacionia buoliana), (Z)-tetradec-11-en-1-yl acetate (European oak leafroller Tortrix viridana), and (3E,8Z,11Z)-tetradeca-3,8,11-trien-1-yl acetate (tomato leafminer Tuta absoluta).
Biotechnological advances for restoring degraded land for sustainable development
Vishal Tripathi, Sheikh Adil Edris, Bin Chen, Vijai K Gupta, P.C. Abhilash, Raivo Vilu and Nicholas Gathergood
Trends in Biotechnology, Volume 35, Issue 9, September 2017, Pages 847-859
dx.doi.org/10.1016/j.tibtech.2017.05.001
Global land resources are under severe threat due to pollution and unsustainable land use practices. Restoring degraded land is imperative for regaining ecosystem services, such as biodiversity maintenance and nutrient and water cycling, and to meet the food, feed, fuel, and fibre requirements of present and future generations. While bioremediation is acknowledged as a promising technology for restoring polluted and degraded lands, its field potential is limited for various reasons. However, recent biotechnological advancements, including producing efficient microbial consortia, applying enzymes with higher degrees of specificity, and designing plants with specific microbial partners, are opening new prospects in remediation technology. This review provides insights into such promising ways to harness biotechnology as ecofriendly methods for remediation and restoration.
Efficient dark fermentative hydrogen production from enzyme hydrolyzed rice straw by Clostridium pasteurianum (MTCC116)
Neha Srivastava, Manish Srivastava, Deepika Kushwaha, Vijai K Gupta, Ambepu Manikanta, P.W. Ramteke and P.K. Mishra
Bioresource Technology. Volume 238, August 2017, Pages 552–558
https://doi.org/10.1016/j.biortech.2017.04.077
In the present work, production of hydrogen via dark fermentation has been carried out using the hydrolyzed rice straw and Clostridium pasteurianum (MTCC116). The hydrolysis reaction of 1.0% alkali pretreated rice straw was performed at 70 °C and 10% substrate loading via Fe3O4/Alginate nanocomposite (Fe3O4/Alginate NCs) treated thermostable crude cellulase enzyme following the previously established method. It is noticed that under the optimized conditions, at 70 °C the Fe3O4/Alginate NCs treated cellulase has produced around 54.18 g/L sugars as the rice straw hydrolyzate. Moreover, the efficiency of the process illustrates that using this hydrolyzate, Clostridium pasteurianum (MTCC116) could produce cumulative hydrogen of 2580 ml/L in 144 h with the maximum production rate of 23.96 ml/L/h in 96 h. In addition, maximum dry bacterial biomass of 1.02 g/L and 1.51 g/L was recorded after 96 h and 144 h, respectively with corresponding initial pH of 6.6 and 3.8, suggesting higher hydrogen production.
Physicochemical properties and esterolytic reactivity of oxime functionalized surfactants in pH-responsive mixed micellar system
Illia V. Kapitanov, Alla B. Mirgorodskaya, Farida G. Valeeva, Nicholas Gathergood, Kamil Kuca, Lucia Ya. Zakharova, Yevgen Karpichev
Colloids and Surfaces A: Physicochemical and Engineering Aspects. Volume 524, 5 July 2017, Pages 143–159
https://doi.org/10.1016/j.colsurfa.2017.04.039
We present a comprehensive study of the aggregation properties of zwitterionic micelles of oxime-functionalized surfactants and their mixed micellar systems with conventional cationic CTABr and nonionic Tween® 80 surfactants. Analysis of the micellar effects on the reaction rates toward activated esters is also completed. Specifically, aggregation properties of micelles of amphiphilic 1-alkyl-3-methyl-2-(oximinomethyl)imidazolium and 1-alkyl-3(1-oximinoethyl)pyridinum bromides (alkyl = CnH2n+1, where n = 12, 16) and their mixed micellar systems with CTABr and Tween® 80 have been investigated. The changes in micellar properties and reaction rates toward 4-nitrophenyl esters of diethyl phosphoric (NPDEP), diethyl phosphonic (NPDEPN), and toluenesulphonic (NPOTos) acids, with increase of pH ensuring deprotonation of specific oximate moiety, have been studied. We focused on the changes of micellar properties of mixed micelles depending on the mixture composition and the deprotonation degree of the functional oximate group. The critical micelle concentration (cmc) values, degrees of counterion binding (β), and size of micellar aggregates were obtained using surface tension measurements, dynamic light scattering method, bromide selective electrode, and by solubilization of hydrophobic dye Orange OT. The surface excess concentration (Гmax, μmol/m2), minimum area per molecule (Amin), interaction parameters (βm), standard Gibbs free energy of adsorption and micellization, and excess free energy of micellization (ΔGex) have been evaluated. Micellar effects of the systems studied on the acyl transfer reaction rates were shown to increase with higher fraction of deprotonated oxime and can be treated in the framework of a pseudophase partitioning model. These results provide new information on (i) control the reactivity of the organized molecular systems and (ii) elaboration the basis for designing pH-responsive supramolecular assemblies.
C3-symmetric opioid scaffolds are pH-responsive DNA condensation agents
Natasha McStay, Zara Molphy, Alan Coughlan, Attilio Cafolla, Vickie McKee, Nicholas Gathergood, Andrew Kellett
Nucleic Acids Research, 2017, Volume 45, Issue 2, Pages 527–540
https://doi.org/10.1093/nar/gkw1097
Herein we report the synthesis of tripodal C3-symmetric opioid scaffolds as high-affinity condensation agents of duplex DNA. Condensation was achieved on both supercoiled and canonical B-DNA structures and identified by agarose electrophoresis, viscosity, turbidity and atomic force microscopy (AFM) measurements. Structurally, the requirement of a tris-opioid scaffold for condensation is demonstrated as both di- (C2-symmetric) and mono-substituted (C1-symmetric) mesitylene-linked opioid derivatives poorly coordinate dsDNA. Condensation, observed by toroidal and globule AFM aggregation, arises from surface-binding ionic interactions between protonated, cationic, tertiary amine groups on the opioid skeleton and the phosphate nucleic acid backbone. Indeed, by converting the 6-hydroxyl group of C3-morphine (MC3) to methoxy substituents in C3-heterocodeine (HC3) and C3-oripavine (OC3) molecules, dsDNA compaction is retained thus negating the possibility of phosphate—hydroxyl surface-binding. Tripodal opioid condensation was identified as pH dependent and strongly influenced by ionic strength with further evidence of cationic amine-phosphate backbone coordination arising from thermal melting analysis and circular dichroism spectroscopy, with compaction also witnessed on synthetic dsDNA co-polymers poly[d(A-T)2] and poly[d(G-C)2]. On-chip microfluidic analysis of DNA condensed by C3-agents provided concentration-dependent protection (inhibition) to site-selective excision by type II restriction enzymes: BamHI, HindIII, SalI and EcoRI, but not to the endonuclease DNase I.
Mandelic acid derived ionic liquids: synthesis, toxicity and biodegradability
Hannah Prydderch, Annette Haiβ, Marcel Spulak, Brid Quilty, Klaus Kümmerer, Andreas Heise and Nicholas Gathergood*
RSC Advances, 2017,7, 2115-2126.
A series of ten ionic liquids (ILs) was synthesised from the renewable resource mandelic acid. The ILs showed low antimicrobial activity towards the thirteen bacterial and twelve fungal strains they were screened against. A general trend of increasing bacterial toxicity in the order methyl ester < ethyl ester < n-butyl ester/amide was observed. IL biodegradability was evaluated using the Closed Bottle test (OECD 301D). Biodegradation increased in the order of increasing alkyl chain length for the ester ILs (methyl < ethyl < n-butyl). Despite none of the ILs presenting as readily biodegradable (> 60 % in 28 days), a series of biodegradation transformation products has been proposed based on the degradation of the ester/amide alkyl chain. This data has allowed for an assessment of the effect of IL structural features on toxicity and biodegradation, particularly allowing for a comparison to earlier work where additional oxygen atoms were present to facilitate biodegradation and attenuate toxicity. The mandelic acid derived ILs did not pass the Closed Bottle test (OECD 301D) and can be included in the rules of thumb for the design of biodegradable ILs.
Opioid architectures as new DNA binding molecules
Natasha McStay, Zara Molphy, Nicholas Gathergood and Andrew Kellett
Symmetry: Culture and Science, 2017, Vol. 28, No. 2, 195-198.
journal-scs.symmetry.hu/content-pages/volume-28-number-2-pages-161-240-2017/
Herein we report the discovery of C3 symmetric opioid architectures as efficient DNA binding molecules. To our knowledge these agents are the first opioidbased structures with nucleic acid recognition properties. These architectures may now pave the way toward the development of a new class of semi-synthetic DNA binding molecule with potential applications in gene delivery
Chiral ionic liquids: Effect of symmetry and stereochemistry on toxicity and biodegradation
Nicholas Gathergood
Symmetry: Culture and Science, 2017, Vol. 28, No. 2, 179-182.
journal-scs.symmetry.hu/content-pages/volume-28-number-2-pages-161-240-2017/
Chiral ionic liquids based on sustainable molecules readily available from natural sources have been developed. Short and efficient synthesis of these salts was achieved. Toxicity and biodegradation studies were performed and have been discussed with respect to symmetry and stereochemistry consideration. The advantages of chemists, biologists and environmental scientists working together towards a common goal were presented
Porphyrinoid based supramolecular probes for chirality sensing
Victor Borovkov and Nicholas Gathergood
Symmetry: Culture and Science, 2017, Vol. 28, No. 2, 175-178.
journal-scs.symmetry.hu/content-pages/volume-28-number-2-pages-161-240-2017/
Porphyrinoid based supramolecular probes to sense chirality of various enantiopure compounds as in solution and in solid state have been designed and developed. Besides, effective chiral recognition achieved by using optically resolved bischlorin hosts and further progress towards chiral functional materials having potential applications in different areas of science and technology have been discussed.
Symmetry and asymmetry phenomena in chemical, green, and related science
Victor Borovkov and Nicholas Gathergood
Symmetry: Culture and Science, 2017, Vol. 28, No. 2, 165−167.
journal-scs.symmetry.hu/content-pages/volume-28-number-2-pages-161-240-2017/
Guest editors' Victor Borovkov and Nicholas Gathergood foreword to a thematic issue "SYMMETRY AND ASYMMETRY PHENOMENA IN CHEMICAL, GREEN, AND RELATED SCIENCES"
Enhanced sensing properties of cobalt bis-porphyrin derivative thinfilms by a magneto-plasmonic-opto-chemical sensor
A. Colombelli, M.G. Manera, V. Borovkov, G. Giancane, L. Valli, R. Rella
Sensors and Actuators B: Chemical. Volume 246, July 2017, Pages 1039–1048
https://doi.org/10.1016/j.snb.2017.01.192
This work reports on the spectroscopic properties and gas sensing performances of cobalt bis-porphyrinderivative ((Co-H)Por2) in a thin films form obtained by Langmuir–Schäfer (LS) method towards VolatileOrganic Compounds (VOCs) and an oxidizing gas in a Magneto-Optical Surface Plasmon Resonance(MO-SPR) configuration. In particular the optical and spectroscopic properties of (Co-H)Por2multilayersdeposited onto proper Au/Co/Au magneto-plasmonic (MP) transducers were inspected in dry air con-ditions and after exposure to different analyte gas concentrations. The molecular organization of thesethin films deposited by Langmuir–Schäfer technique has been investigated and a comparison betweenthe MOSPR experimental data and simulation has been also reported.In order to validate our experimental results and obtain further insight into the physical mechanismof interaction between the organometallic molecules and magneto plasmonic nanostructured systems,numerical simulations based on Finite Element Method (FEM) techniques, have been performed. Theoptical and magneto-optical properties of these hybrid systems have been theoretically analyzed to con-firm the experimental outcomes. Finally, a peculiar sensitivity of the MOSPR sensing probe in respect toinvestigated analytes has been recorded.
Sui Generis Helicene-Based Supramolecular Chirogenic System: Enantioselective Sensing, Solvent Control, and Application in Chiral Group Transfer Reaction
Mohammed Hasan, Vaibhav N. Khose, Tadashi Mori, Victor Borovkov and Anil V. Karnik
ACS Omega, 2017, 2 (2), pp 592–598
http://pubs.acs.org/doi/full/10.1021/acsomega.6b00522
A novel dioxa[6]helicene-based supramolecular chirogenic system (1) as a specific chiral recognition host for enantiopure trans-1,2-cyclohexanediamine (2) is reported. Host 1 with an inherent free phenolic group and a (1S)-camphanate chiral handle on the opposite terminal rings of the helicene chromophore acted as an efficient turn on fluorescent sensor for S,S-2with an excellent enantioselective factor, α = KSS/KRR = 6.3 in benzene. This specific host–guest interaction phenomenon is found to be solvent-dependent, which leads to an enantioselective chiral (camphanate) group transfer to the diamine guest molecule. In the case of R,R-2, the de value is up to 68% even at room temperature. Intriguingly, the induced helicity in dioxa[6]helicene diol 6, upon supramolecular hydrogen-bonding interactions, is of opposite sense with positive helicity for S,S-2 and negative helicity for R,R-2, as shown by circular dichroism spectroscopy and in combination with theoretical calculations. This chiral supramolecular system is found to be an excellent host–guest pair for enantiomeric recognition of 2, based on their electronic and steric factors.
25 years of the concept of green chemistry and green engineering
In celebration of the past 25 years of green chemistry and engineering the journal ACSSustainable Chemistry & Engineering published a special issue in November 2016. Read more
Nicholas Gathergood
Chair of EuCheMS Division of Green and Sustainable Chemistry
Effect of structure of polycyclic aromatic substrates on solubilization capacity and size of cationic monomeric and gemini 14-s-14 surfactant aggregates
Anna A. Serdyuk, Alla B. Mirgorodskaya, Illia V. Kapitanov, Nicholas Gathergood, Lucia Ya Zakharova, Oleg G. Sinyashin, Yevgen Karpichev
Colloids and Surfaces A: Physicochemical and Engineering Aspects. Volume 509, 20 November 2016, Pages 613–622
https://doi.org/10.1016/j.colsurfa.2016.09.068
Monocationic surfactants cetyltrimethylammonium bromide (CTABr), cetyldimethyl(2-hydroxyethyl)ammonium bromide (CHDABr), and dicationic (gemini) surfactants, alkanediyl-α,ω-bis(dimethyltetradecylammonium bromides) (14-s-14, where s = 2, 4, 6) were studied in the solubilization of polycyclic aromatic compounds (PAC) anthracene, naphthalene, and organic dye alizarin. By means of UV-vis was found that gemini 14-s-14 surfactants demonstrate 2-4 times higher solubilisation capacity compared to the monomer surfactants. Solubilization of anthracene increases in the series 14-2-14 : 14-4-14 : 14-6-14 whereas naphthalene does not demonstrate remarkable sensitivity to the spacer length. Solubilization profile of Alizarin undergoes a break point causing lower solubilisation capacity at high surfactant concentration. The aggregates size was shown using DLS method to be dependent on solubilizate structure and nature and concentration of surfactant.
Degradation of Organophosphate Pesticides Using Pyridinium Based Functional Surfactants
Rahul Sharma, Bhanushree Gupta, Toshikee Yadav, Srishti Sinha, Arvind Kumar, Yevgen Karpichev*, Nicholas Gathergood, Jan Marek, Kamil Kuca, Kallol K. Ghosh*.
ACS Sustainable Chemistry and Engineering, 2016, 4 (12), pp 6962–6973
Publication date: October 7, 2016
http://dx.doi.org/10.1021/acssuschemeng.6b01878
The enhancement of environmental quality is one of the key principles of sustainable agriculture which points lesser use of synthetic pesticides and chemical fertilizers. Green chemistry offers an array of innovative approaches to develop safe and efficient methods of its chemical transformation towards nontoxic readily biodegradable products under mild conditions. The development of new strategies for chemical decontamination of organophosphorus nerve agents and pesticides is an issue of immediate concern. Oximes have been demonstrated to find an application as functionalized organized molecular systems. In this study, kinetic investigations have been explored to estimate the nucleophilic efficiency of oxime-functionalized pyridinium surfactants 3-hydroxyiminomethyl-1-alkylpyridinium bromide (alkyl=CnH2n+1, n=10, 12, 14, 16) and 4-hydroxyiminomethyl-1-alkylpyridinium bromide (alkyl=CnH2n+1, n=10, 12) for the hydrolysis of pesticides paraoxon (NPDEP) and methyl paraoxon (NPDMP) in the mixed micelles with conventional cationic surfactants CPB, CTAB and CDMEAB. Comprehensive study of surface properties and acid-base equilibria of micellar system composed by (i) functionalized surfactants and (ii) mixed functionalized / conventional cationic micelles have been carried out. pKa of studied nucleophiles in the presence of surfactants has also been monitored. Effect of pH, co-micellar effect of other surfactants and alkyl chain length of functionalized surfactants has been monitored on the observed rate constants of cleavage of studied organophosphate.
Enantioselective Tsuji-Trost Reactions in Low Toxicity Ionic Liquids
Mukund Ghavre, Brid Quilty and Nicholas Gathergood
Current Green Chemistry. 2016, Vol. 3, Iss. 2. P. 181 - 189
https://doi.org/10.2174/2213346103666160728115628
Low toxicity ionic liquids (ILs) were prepared by a facile synthesis. The palladium based catalyst bearing asymmetric ligand was immobilized in these ILs. This ‘green’ catalytic system was employed for enantioselective Tsuji-Trost reactions. For comparison, a few reactions were run in conventional solvents. The reactions in ILs provided good to excellent enantiomeric excess, however, low yields were obtained as compared to conventional solvents. The catalytic system as a whole is recyclable. The low yields are attributed to high viscosity of the ILs, and can be resolved by tuning the viscosity by anion exchange.
On the way to greener ionic liquids: identification of a fully mineralizable phenylalanine-based ionic liquid
Annette Haiß, Andrew Jordan, Janin Westphal, Evgenia Logunova, Nicholas Gathergood, Klaus Kümmerer
Green Chem., 2016, 18, 4361-4373
Article dx.doi.org/10.1039/C6GC00417B
Graphical Abstract
Biodegradability screening of L-phenylalanine based ionic liquids and neutral analogues and LC-HRMS analysis of the degradation products resulted in the identification of a pyridinium IL which was fully mineralizable and is proposed as a basic structure of green IL.
Synthesis of a series of amino acid derived ionic liquids and tertiary amines: green chemistry metrics including microbial toxicity and preliminary biodegradation data analysis
Andrew Jordan, Annette Haiß, Marcel Spulak, Yevgen Karpichev, Klaus Kümmerer, Nicholas Gathergood
Green Chem., 2016, 18, 4374-4392
Article dx.doi.org/10.1039/C6GC00415F
Graphical Abstract
A series of L-phenylalanine ionic liquids (ILs), L-tyrosine ILs, tertiary amino analogues and proposed transformation products (PTPs) have been synthesised. Antimicrobial toxicity data, as part of the green chemistry metrics evaluation and to supplement preliminary biodegradation studies, was determined for ILs, tertiary amino analogues and PTPs. Good to very good overall yields (76 to 87%) for the synthesis of 6 ILs from L-phenylalanine were achieved. A C2-symmetric IL was prepared from TMS-imidazole in a one-pot two-step method in excellent yield (91%). Synthesis of the L-tyrosine IL derivatives utilised a simple protection group strategy by using an extra equivalent of the bromoacetyl bromide reagent. Improvements in the synthesis of the α-bromoamide alkylating reagent from L-phenylalanine were achieved, directed by green chemistry metric analysis. A solvent switch from dichloromethane to THF is described, however the yield was 15% lower. Antimicrobial activity testing of L-phenylalanine ILs, L-tyrosine ILs, tertiary amino analogues and PTPs, against 8 bacteria and 12 fungi strains, showed that no compound had a high antimicrobial activity, apart from an L-proline analogue. In this exceptional case, the highest toxicity (IC95 = 125 and 250 μM) was observed towards the two Gram positive strains Staphylococcus aureus and Staphylococcus epidermidis respectively. High antimicrobial activity was not found for the other bacteria or fungi strains screened. The limitations of the antimicrobial activity study is discussed in relation to SAR studies. Preliminary analysis of biodegradation data (Closed Bottle Test, OECD 301D) is presented. The pyridinium IL derivative is the preferred green IL of the series based on synthesis, toxicity and biodegradation considerations. This work is a joint study with Kümmerer and co-workers and the PTPs were selected as target compounds based on concurrent biodegradation studies by the Kümmerer group. For the comprehensive biodegradation and transformation product analysis see the accompanying paper.
Amino Acid-Functionalized Calix[4]Resorcinarene Solubilization by Mono- and Dicationic Surfactant
Lucia Ya. Zakharova, Anna A. Serdyuk, Alla B. Mirgorodskaya, Illia V. Kapitanov, Gulnara A. Gainanova, Yevgen Karpichev, Elena L. Gavrilova, Oleg G. Sinyashin
Journal of Surfactants and Detergents, 2016, Volume 19, Issue 3, pp 493–499
http://link.springer.com/article/10.1007/s11743-016-1792-0
Poorly water-soluble calix[4]resorcinarenes modified with amino acid (Ala, Val) at the upper rim formed a water-soluble mixed system with micelles of monocationic surfactants cetyltrimethylammonium bromide, cetyldimethyl(2-hydroxyethyl)ammonium bromide, and dicationic (gemini) surfactants, alkanediyl-α,ω-bis(dimethyltetradecylammonium bromides (14-s-14, where s = 2, 4, or 6). UV–Vis and DLS methods demonstrated that the micellar systems of surfactant/functionalized calix[4]resorcinarene underwent structural changes within a relatively narrow concentration range followed by changes in solubilization capacity and polydispersity. Gemini surfactants and monocationic/gemini mixed surfactant systems were provided selectivity in their interaction with calix[4]resorcinarene depending on the bulkiness of the substituent at the upper rim of calix[4]resorcinarene, gemini surfactant spacer length, and mixed micelles. These systems represent a direction to create biocompatible water-soluble functionalized calix[4]resorcinarene composition and may open perspectives in designing organized systems with controllable properties.
Tailor-Made Supramolecular Chirogenic System Based on Cs-Symmetric Rigid Organophosphoric Acid Host and Amino Alcohols: Mechanistic Studies, Bulkiness Effect, and Chirality Sensing
Mohammed Hasan, Vaibhav N. Khose, Anita D. Pandey, Victor Borovkov, and Anil V. Karnik
Org. Lett., 2016, 18 (3), pp 440–443. DOI: 10.1021/acs.orglett.5b03477
http://pubs.acs.org/doi/abs/10.1021/acs.orglett.5b03477
A Cs-symmetric, rigid, achiral organophosphoric acid host with differentiable tautomeric structures has been developed for induced circular dichroism (ICD) studies of vicinal amino alcohols. The structural features of the host and the substituent bulkiness of the guest, together, decide the preferred mode of hydrogen binding on equilibration with a resultant ICD signal. An unequivocal rule correlating the absolute configuration of the guest amino alcohol with the ICD outcome is proposed.
Conformational switching of ethano-bridged Cu,H2-bis-porphyrin induced by aromatic amines
Bettini, S.; Maglie, E.; Pagano, R.; Borovkov, V.; Inoue, Y.; Valli, Ludovico, Giancane, G.
Beilstein J. Nanotechnol. 2015 (6), 2154–2160. DOI:10.3762/bjnano.6.221
https://www.beilstein-journals.org/bjnano/articles/6/221
Cu,H2-bis-porphyrin (Cu,H2-Por2), in which copper porphyrin and free-base porphyrin are linked together by an ethano-bridge, was dissolved in chloroform and spread at the air/liquid subphase interface of a Langmuir trough. The bis-porphyrin derivative, floating film was characterized by reflection spectroscopy and the surface pressure of the floating film was studied as a function of the mean area per molecule. When aromatic amines are dissolved in the subphase, an evident interaction between the bis-porphyrin host and the aromatic amine guest is observed. A clear-cut variation of the profile of surface pressure vs area per molecule curve is observed. Reflection spectroscopy highlights that the aromatic amines dissolved in the subphase are able to induce the syn-to-anti con- formational switching in the bis-porphyrin derivative. The Langmuir–Schaefer technique has been used to transfer the floating bis- porphyrin film (when using pure water as a subphase) to a surface plasmon resonance (SPR) substrate and the resulting device was able to detect the presence of aniline at concentrations as low as 1 nM in aqueous solution. The high selectivity of the SPR sensing device has been verified by checking the spectral response of the active layer towards other analytes dissolved in the aqueous solutions.
Chinese translation of Biomass Processing and Conversion Book
We are pleased to announce that the book The Role of Green Chemistry in Biomass Processing and Conversion edited by Prof. Gathergood and Assoc. Prof. Xie and published by Wiley is now available in Chinese. This will enable a wider readership of our work and assist in promoting green chemistry principles in China. A review of the book by Martin Mulvihill, Executive Director of the Berkeley Centre for Green Chemistry, University of California, Berkeley states, ´Editors Haibo Xie, and Nicholas Gathergood have done an excellent job organizing their recently published book The Role of Green Chemistry in Biomass Processing and Conversion. This book is an excellent resource for chemists interested in understanding the current state of the art for biomass processing. Compared to other books in the biomass processing field this one focuses more on the molecular level transformations, without losing site of the broader context and drivers for biomass derived chemicals. This advance text is likely to appeal to chemistry students and faculty interested in considering new research in this area, or current researchers and practitioners that want to stay up-to-date concerning the recent technology advances.
The book highlights all of the major classes of process methods used to transform biomass into more valuable chemicals or fuels, while focusing on the chemical methods. They cover chemical methods (ionic liquids, heterogeneous catalysis, super critical CO2, etc.), thermochemical processes (pyrolysis, microwaves, and ultrasonics), and one chapter on microbial technologies. Importantly, this book also considers some of the broader implications of these new technologies including environmental and eco-toxicity impacts of various biofuels and processes. I am currently teaching a interdisciplinary graduate class related to biofuel processing and have found this book to be an excellent resource for my lectures and for the chemistry students who are interested in digging a little deeper.
Links to further details about Chinese edition are available from major online stores:
- AmazonCN.COM
- JD.COM
- http://item.jd.com/11661888.html
- dangdang.com
- http://product.dangdang.com/23662614.html
- The English version is widely available including from amazon.com
Toxicity and bioacceptability in the context of biological processes in ionic liquid media
Prydderch, H.; Heise, A.; Gathergood, N. (2015). Toxicity and bioacceptability in the context of biological processes in ionic liquid media. Lukasik, R. (Eds.). Ionic Liquids in the Biorefinery Concept. Royal Soc Chemistry
http://pubs.rsc.org/en/content/ebook/978-1-84973-976-4#!divbookcontent
An Organocatalytic Process for the Hydrolytic Cleavage of Dithianes Mediated by Imidazolium Ions: No Harsh Agents Required
Myles, L.; Gathergood, N.; Connon, S. J.
European Journal of Organic Chemistry, 2015 (1), 188 - 194.
http://dx.doi.org/10.1002/ejoc.201402947
A new, organocatalytic approach to the hydrolytic deprotection of dithianes has been developed involving a low-toxicity imidazolium-ion-based catalyst in an aqueous medium. A complimentary solvent-free method without added water and involving a sacrificial aldehyde is also reported. The catalyst does not appear to operate by a specific-acid catalysis mechanism.
Amphiphilic glycosylated block copolypeptides as macromolecular surfactants in the emulsion polymerization of styrene
Jacobs, J.; Gathergood, N.; Heuts, J.P.A.; Heise, A.
Polymer Chemistry, 2015, 6 (25), 4634 - 4640.
http://dx.doi.org/10.1039/C5PY00548E
Diblock copolymers consisting of poly(L-phenyl alanine) and poly(benzyl-L-glutamate) or poly(CBZ-L-lysine), respectively, were synthesized via sequential NCA polymerization. After deprotection, subsequent partial glycosylation of the glutamic acid and lysine units with galactosamine hydrochloride or lactobionic acid yielded amphiphilic block copolypeptides. Moreover, a triblock copolymer poly(L-phenyl alanine-b-L-benzyl glutamate-b-propargylglycine) was obtained and glycosylated by ‘click’ chemistry. Glycosylated block copolypeptides showed improved water solubility and circular dichroism (CD) confirmed the pH dependence of the helix-coil transition. The block copolypeptides were found to be efficient stabilizers in the emulsion polymerization of styrene offering a facile method for the synthesis of polystyrene nanoparticles in the range of 100–140 nm depending on the block copolymer composition and emulsion concentration. This establishes an example of functional polymer additives fully based on renewable building blocks in nanomaterial synthesis.
Biodegradation of ionic liquids – a critical review
Andrew Jordan and Nicholas Gathergood*
Chem. Soc. Rev., 2015, 44, 8200-8237; DOI: 10.1039/C5CS00444F
http://pubs.rsc.org/en/Content/ArticleLanding/2015/CS/c5cs00444f#!divAbstract
The importance of biodegradation data as part of the design of safer chemicals is presented using ionic liquids (ILs) as a model study. Structural features that promote/impede IL biodegradation, IL design strategies, methods of biodegradation analysis, properties of IL/surfactant derivatives and computational methods of predicting biodegradation are discussed. The importance of metabolite studies as part of biodegradation assays is highlighted. The relevance of applying the lessons learned developing biodegradable ILs to other chemical classes is proposed. A comprehensive appendix of IL biodegradation data published since 2010 (∼300 ILs) has been compiled.
