Valorization of renewable cellulose into initial platform chemicals(IPCs)generally suffers from low process efficiency owing to difficult depolymerization of recalcitrant cellulose and troublesome repolymerization of ...Valorization of renewable cellulose into initial platform chemicals(IPCs)generally suffers from low process efficiency owing to difficult depolymerization of recalcitrant cellulose and troublesome repolymerization of high-reactive intermediates to undesired humins.Herein,we report a double-protective strategy for cellulose depolymerization and orientated conversion to levulinic acid(LA),one of the important IPCs,by in-situ adding protective formaldehyde(HCHO).This approach initiates from the(hemi)acetalation of hydroxyl groups in cellulose with HCHO,causing controllable depolymerization to(hemi)acetalized glucose with increased rate kinetically and a new mechanism of its catalytic conversion to LA via(hemi)acetal-driven direct C1-C2 cleavage.As such,the cellulose-to-LA conversion is protectively proceeded with the repolymerization of reactive intermediates prevented remarkably,leading to an excellent LA yield of 87.3 mol% from high-loading microcrystalline cellulose(15.0 wt% in aqueous phase)in a biphasic solvent containing 2-methyltetrahydrofuran and water.The process efficiency,expressed as space-time yield,is improved by 3.6 fold when compared with a non-protective approach.This work highlights an advance in maximizing the utilization of biomass-derived carbons for high-efficiency production of important IPCs directly from cellulose for future biorefinery.展开更多
Conversion of biomass to chemicals or fuels under mild condition is still a challenge. As a platform molecule for chemicals and fuels, levulinic acid （LA） has been prepared by lique-faction of biomass at high pressu...Conversion of biomass to chemicals or fuels under mild condition is still a challenge. As a platform molecule for chemicals and fuels, levulinic acid （LA） has been prepared by lique-faction of biomass at high pressure. In order to carry out the conversion from wheat straw to LA at atmosphere pressure, continuous extraction of the reactive system by an organic solvent with a higher density than that of water was utilized for degradation of pretreated biomass. Yields of LA were measured by means of gas chromatography-mass spectrometry and nuclear magnetic resonance. The results revealed that a maximum yield of 30.66% of LA can be obtained from wheat straw. In addition, the effects of biomass pretreated conditions on the LA conversion have been studied. The study provides a new route to convert biomass to valuable chemicals at atmosphere pressure.展开更多
Levulinic acid has been identified as a promising green, biomass-derived platform chemical. n-Butyl levulinate is used as an important intermediate having diverse applications. The present work focuses on the synthesi...Levulinic acid has been identified as a promising green, biomass-derived platform chemical. n-Butyl levulinate is used as an important intermediate having diverse applications. The present work focuses on the synthesis of n-butyl levulinate by esterification of levulinic acid with n-butanol using heteropolyacid （HPA） supported on acid-treated clay montmorillonite （K10）. 20% （w/w） dodecatungestophosphoric acid （DTPA） supported on K10 was found to be the most efficient catalyst with 97% levulinic acid conversion and 100% selectivity towards n-butyl levulinate. Effects of various process parameters were studied to examine the efficacy of 20% （w/w） DTPA/K10 for optimization of the activity.展开更多
Levulinic acid is a kind of new green platform chemical with wide application. The kinetics of levulinic acid formation from glucose decomposition at high temperature was investigated. Glucose containing 1%, 3% or 5% ...Levulinic acid is a kind of new green platform chemical with wide application. The kinetics of levulinic acid formation from glucose decomposition at high temperature was investigated. Glucose containing 1%, 3% or 5% H2SO4 was treated at 170℃ or 190℃. For the various experimental conditions assayed, the time-courses of glucose and glucose degradation products (including 5-hydroxymethylfurfural and levulinic acid) were established. These variables were cor-related with the reaction time based on the equations derived from a pseudo-homogeneous, first-order kinetic model, which provided a satisfactory interpretation of the experimental results. The set of kinetic parameters from regression of experimental data provided useful information for understanding the levulinic acid formation mechanism.展开更多
Bimetallic nanostructures have attracted great interest as efficient catalyst to enhance activity,selectivity and stability in catalytical conversion.Herein,we report a facile one‐pot carbothermal route to in‐situ c...Bimetallic nanostructures have attracted great interest as efficient catalyst to enhance activity,selectivity and stability in catalytical conversion.Herein,we report a facile one‐pot carbothermal route to in‐situ controllable synthesize heterogeneous bimetallic Ni3Fe NPs@C nanocatalyst.The X‐ray diffraction,transmission electron microscopy,X‐ray photoelectron spectroscopy and N2 adsorption‐description results reveal that the Ni3Fe alloy nanoparticles are evenly embedded in carbon matrix.The as‐prepared Ni3Fe NPs@C catalyst shows excellent selective hydrogenation catalytic performance toward the conversion of levulinic acid(LA)toγ‐valerolactone(GVL)via both direct hydrogenation(DH)and transfer hydrogenation(TH).In DH of LA,the bimetallic catalyst achieved a 93.8%LA conversion efficiency with a 95.5%GVL selectivity and 38.2 mmol g–1 h–1 GVL productivity(under 130°C,2MPa H2 within 2 h),which are 6 and 40 times in comparison with monometallic Ni NPs@C and Fe NPs@C catalysts,respectively.In addition,the identical catalyst displayed a full conversion of LA with almost 100%GVL selectivity and 167.1 mmol g–1 h–1 GVL productivity at 180°C within 0.5 h in TH of LA.Under optimal reaction conditions,the DH and TH catalytic performance of 500‐Ni3Fe NPs@C(3:1)catalyst for converting LA to GVL is comparable to the state‐of‐the‐art noble‐based catalysts.The demonstrated capability of bimetallic catalyst design approach to introduce dual‐catalytic functionality for DH and TH reactions could be adoptable for other catalysis processes.展开更多
Levulinic acid（LA） has been identified as a promising green,biomass derived platform chemical.Response surface analysis（RSA） with a four-factor-five-level central composite design（CCD） was applied to optimize th...Levulinic acid（LA） has been identified as a promising green,biomass derived platform chemical.Response surface analysis（RSA） with a four-factor-five-level central composite design（CCD） was applied to optimize the hydrolysis conditions for the conversion of bamboo（Phyllostachys Praecox f.preveynalis） shoot shell（BSS） to LA catalyzed with ionic liquid [C4mim]HSO4.The effects of four main reaction parameters including temperature,time,C[C4mim]HSO4（initial [C4mim]HSO4 concentration） and XBSS（initial BSS intake） on the hydrolysis reaction for yield of LA were analyzed.A quadratic equation model for yield of LA was established and fitted to the data with an R2 of 0.9868,and effects of main factors and their corresponding relationships were obtained with RSA.Model validation and results of CCD showed good correspondence between actual and predicted values.The analysis of variance（ANOVA） of the results indicated that the yield of LA in the range studied was significantly（P＆lt;0.05） affected by the four factors.The optimized reaction conditions were as follows：temperature of 145 ℃,time of 103.8 min,C[C4mim]HSO4 of 0.9 mol.L-1 and XBSS of 2.04%（by mass）,respectively.A high yield [（71±0.41）%（by mol）,triplicate experiment] was obtained at the optimum conditions of temperature of 145 ℃,time of 104 min,C[C4mim]HSO4 of 0.9 mol.L-1 and XBSS of 2%（by mass）,which obtained from the real experiments,concurred with the model prediction [73.8%（by mol） based on available C6 sugars in BSS or 17.9%（by mass） based on the mass of BSS],indicating that the model was adequate for the hydrolysis process.展开更多
Herein,we reported in situ synthesis of biomass-derived Ni/C catalyst by self-reduction with pomelo peel.Compared with the conventional method, which includes carbonization, activation, impregnation and reduction, the...Herein,we reported in situ synthesis of biomass-derived Ni/C catalyst by self-reduction with pomelo peel.Compared with the conventional method, which includes carbonization, activation, impregnation and reduction, the entire preparation process was simplified to two steps, which was more straightforward. This synthesis method was green as Ni/C can be prepared without any additional chemical and the self-reduction process was realized in N2, which can avoid using H2 thus averting some problems such as storage, transportation and safety of H2. Meanwhile, the size and dispersion of Ni particles can be controlled by changing carbonization temperature.The synthesis mechanism of Ni/C catalyst with selfreduction was investigated, which was mainly attributed to the carbon and reducing gas produced during the carbonization process.For the catalytic performance of GVL synthesis, a high yield (94.5%) can be obtained and it exhibited good stability up to 5 cycles without obvious loss of catalytic activity.展开更多
Levulinic acid is considered as a promising green platform chemical derived from biomass.The kinetics of levulinic acid accumulation in the hydrolysis process of wheat straw was investigated in the study.Using dilute ...Levulinic acid is considered as a promising green platform chemical derived from biomass.The kinetics of levulinic acid accumulation in the hydrolysis process of wheat straw was investigated in the study.Using dilute sulfuric acid as a catalyst,the kinetic experiments were performed in a temperature range of 190-230°C and an acid concentration range of 1%-5% (by mass) .A simple model of first-order series reactions was developed,which provided a satisfactory interpretation of the experimental results.The kinetics of main intermediates including sugar and 5-hydroxymethylfurfural(5-HMF) were also established.The kinetic parameters provided useful information for understanding the hydrolysis process.展开更多
Here we exquisitely fabricated Cu/ZrO_(2)-dp catalysts with plentiful Cu-ZrO_(2)interfaces by depositing amorphous ZrO_(2)onto Cu nanoparticles for the hydrogenation of levulinic acid(LA)to y-valerolactone(GVL).With t...Here we exquisitely fabricated Cu/ZrO_(2)-dp catalysts with plentiful Cu-ZrO_(2)interfaces by depositing amorphous ZrO_(2)onto Cu nanoparticles for the hydrogenation of levulinic acid(LA)to y-valerolactone(GVL).With the created plentiful CU-ZrO_(2)interfaces,the optimal catalyst 3 Cu/ZrO_(2)-dp exhibited exceptional catalytic performance under mild reaction conditions,and achieved the highest GVL mass productivity of 266.0 mmol GVL·h^(-1)·g^(-1)Cu,which was 12.5 and 2.3 times of CU/ZrO_(2)catalysts with equivalent Cu loadings prepared by traditional impregnation(3 Cu/ZrO_(2)-im)or co-precipitation(3 Cu/ZrO_(2)-cp).As far as we know,this GVL mass productivity stood at the highest level compared with those obtained using non-noble metal catalysts under similar reaction conditions.By systematic investigation with multiple characterizations,density functional theory(DFT)calculations,and kinetic studies,it was found that interfacial active centers were created at Cu-ZrO_(2)interfaces,which contained oxygen vacancies(O_(v)),negatively charged Cu^(δ)-and partially reduced Zr^(3+)The O_(v) favored the adsorption and activation of LA via its ketone group,while negatively charged Cu^(δ)-was able to enhance heterolysis of H2,which resulted in the formation of H^(+)-Cu^(δ)-and Zr^(3+)-H^(-)active species via hydrogen spillover.Also,plentiful acid sites,which derived from coordinatively unsaturated and defective Zr species,generated at Cu-ZrO_(2)interfaces.With the cooperation of interfacial active centers(Cu^(δ-)-O_(v)-Zr^(3+))and acid sites,the fabricated 3 Cu/ZrO_(2)-dp with plentiful Cu-ZrO_(2)interfaces achieved excellent catalytic performance for the hydrogenation of LA to GVL.Hence,the synergistic catalysis of Cu-ZrO_(2)interfaces provided an effective strategy for designing catalysts with a satisfactory performance for the hydrogenation of LA,which also can be expanded to other hydrodeoxygenation reactions.展开更多
Levulinic acid(LA)is one of the top-12 most promising biomass-based platform chemicals,which has a wide range of applications in a variety of fields.However,separation and purification of LA from aqueous solution or a...Levulinic acid(LA)is one of the top-12 most promising biomass-based platform chemicals,which has a wide range of applications in a variety of fields.However,separation and purification of LA from aqueous solution or actual hydrolysate continues to be a challenge.Among various downstream separation technologies,liquid-liquid extraction is a low-cost,effective,and simple process to separate LA.The key breakthrough lies in the development of extractants with high extraction efficiency,good hydrophobicity,and low cost.In this work,three hydrophobic deep eutectic solvents(DESs)based on tri-n-octylamine(TOA)as hydrogen bond acceptor(HBA)and alcohols(butanol,2-octanol,and menthol)as hydrogen bond donors(HBDs)were developed to extract LA from aqueous solution.The molar ratios of HBD and HBA,extraction temperature,contact time,solution pH,and initial LA concentration,DES/water volume ratios were systematically investigated.Compared with 2-octanol-TOA and menthol-TOA DES,the butanol-TOA DES exhibited the superior extraction performance for LA,with a maximum extraction efficiency of 95.79±1.4%.Moreover,the solution pH had a great impact on the LA extraction efficiency of butanol-TOA(molar ratio=3:1).It is worth noting that the extraction equilibrium time was less than 0.5 h.More importantly,the butanol-TOA(3:1)DES possesses good extraction abilities for low,medium,and high concentrations of LA.展开更多
The hydrogenation of levulinic acid(LA)to c-valerolactone(GVL)by using water as solvent is a crucial process in the production of fine chemicals from biomass.An ultrathin carbon layer coating CoRu bimetallic catalyst ...The hydrogenation of levulinic acid(LA)to c-valerolactone(GVL)by using water as solvent is a crucial process in the production of fine chemicals from biomass.An ultrathin carbon layer coating CoRu bimetallic catalyst supported on silica(CoRu@C/SiO2)is prepared by using tannis-ligated cobalt-ruthenium complex on silica as precursors,and applied for catalyzed synthesis of GVL from LA.Because of the synergistic effect between cobalt and ruthenium,the addition of small amounts of Ru to Co catalysts can increase the catalytic activity in the aqueous hydrogenation of LA.The ultrathin carbon layer covered on the CoRu bimetallic catalyst can greatly reduce the leaching of active metals.The CoRu@C/SiO2 catalyst achieves high stability and is reused up to 5 runs without significant loss of performance in aqueous hydrogenation of levulinic acid.展开更多
A novel pH gradient methodology was used to synthesise a series of Cu–ZrO2 catalysts containing different quantities of Cu and Zr.All of the catalysts were highly selective to the desired product,γ-valerolactone, an...A novel pH gradient methodology was used to synthesise a series of Cu–ZrO2 catalysts containing different quantities of Cu and Zr.All of the catalysts were highly selective to the desired product,γ-valerolactone, and are considerably more stable than Cu–ZrO2 catalysts prepared by other co-precipitation methods for this reaction.Characterisation and further investigation of these catalysts by XRD, BET, SEM and XPS provided insight into the nature of the catalytic active site and the physicochemical properties that lead to catalyst stability.We consider the active site to be the interface between Cu/CuOxand ZrOx and that lattice Cu species assist with the dispersion of surface Cu through the promotion of a strong metal support interaction.This enhanced understanding of the active site and roles of lattice and surface Cu will assist with future catalyst design.As such, we conclude that the activity of Cu–ZrO2 catalysts in this reaction is dictated by the quantity of Cu–Zr interface sites.展开更多
The construction of an acid resistant catalyst for synthesis of γ-valerolactone from levulinic acid in aqueous media is an important but highly challenging goal.Herein,an efficient Co@NCNT-800(after 800℃ pyrolysis) ...The construction of an acid resistant catalyst for synthesis of γ-valerolactone from levulinic acid in aqueous media is an important but highly challenging goal.Herein,an efficient Co@NCNT-800(after 800℃ pyrolysis) catalyst was constructed by confining Co in N-doped carbon nano-tubes(NCNT) from low cost materials by a facile strategy.Combined with the characterization results and control experiments,the in situ formed Co and Co-Ox, but not Co-Nx, proved to be the main synergistic active sites of the catalyst.It was also found that Co species are completely isolated within the bamboo-like NCNT,which could protect the metal nanoparticles from agglomeration and leaching in the strong acid reaction system.The γ-valerolactone yield of no less than 99.9% can be obtained under a relatively mild condition,and the catalytic performance has not been significantly reduced within five cycles.Therefore,this work may pave a way for the design of robust non-noble catalyst,and has potential for the production of γ-valerolactone from biomass in large-scale industries.展开更多
Levulinic acid(LA)is a platform biorefinery chemical from biomass which can be converted to green solvents,plasticizers,polymer precursors,biobased cleaning agents,fuels and fuel additives.This study assessed the pote...Levulinic acid(LA)is a platform biorefinery chemical from biomass which can be converted to green solvents,plasticizers,polymer precursors,biobased cleaning agents,fuels and fuel additives.This study assessed the potential of SnCl_(2)-based mixed acid systems as catalyst in the hydrothermal conversion of microcrystalline cellulose to levulinic acid.Maximum LAyield of 36.2 mol%was achieved using 0.2 M SnCl_(2) concentration at test conditions of 3 h,180℃ and 1%w/v cellulose loading.To reduce precipitate formation and further improve LA yield,the strategy employed was to combine SnCl_(2)(a Lewis acid)with conventional mineral acids(Bronsted acids).Evaluation of the catalytic performance of SnCl_(2)-HCl,SnCl_(2)-H_(2)SO_(4),SnCl_(2)-HNO_(3),and SnCl_(2)-H_(3)PO_(4)(1:1 molar ratio,0.2 M total acid concentration)were done with highest LA yield of 47.0 mol%obtained using the SnCl_(2)-HCl system at same test conditions.Response surface methodology optimization employing Box-Behnken design generated a quadratic model with a high coefficient of determination(r2)of 0.964.A maximum LA yield of 63.5 mol%can be achieved at 0.17 M catalyst concentration,198℃,and 5.15 h reaction time.Rate constants were estimated using nonlinear regression,while activation energies were determined using Arrhenius equation.Cellulose hydrolysis was determined to be the rate-limiting step in the overall process.Low activation energy of 63.3 kJ/mol for glucose dehydration to hydroxymethylfurfural supports the action of SnCl_(2) as Lewis acid in the mixed-acid system.LA yield simulations for plug flow reactor(PFR)and continuous stirred tank reactor(CSTR)were done suggesting a similar PFR-CSTR configuration with the established Biofine process.Lastly,a reaction scheme was presented to explain the synergy between SnCl_(2) and HCl in LA production from cellulose.展开更多
Developing a highly active and durable non-noble metal catalyst for aqueous-phase levulinic acid(LA)hydrogenation to g-valerolactone(GVL)is an appealing yet challenging task.Herein,we report well-dispersed Co nanopart...Developing a highly active and durable non-noble metal catalyst for aqueous-phase levulinic acid(LA)hydrogenation to g-valerolactone(GVL)is an appealing yet challenging task.Herein,we report well-dispersed Co nanoparticles(NPs)embedded in nitrogen-doped mesoporous carbon nanofibers as an efficient catalyst for aqueous-phase LA hydrogenation to GVL.The Co zeolitic imidazolate framework(ZIF-67)nanocrystals were anchored on the sodium dodecyl sulfate modified wipe fiber(WF-S),yielding one-dimensional(1-D)structured composite(ZIF-67/WF-S).Subsequently,Co NPs were uniformly embedded in nitrogen-doped mesoporous carbon nanofibers(Co^(R)NC/SMCNF)through a pyrolysis-reduction strategy using ZIF-67/WF-S as the precursor.Benefiting from introducing modified wipe fiber WF-S to enhance the dispersion of Co NPs,and Co^(0) with Co-N_xdual active sites,the resulting Co^(R)NC/SMCNF catalyst shows brilliant catalytic activity(206 h^(-1) turnover frequency).Additionally,the strong metal-support interactions greatly inhibited the Co NPs from aggregation and leaching from the mesoporous carbon nanofibers,and thus increasing the reusability of the Co^(R)NC/SMCNF catalyst(reusable nine times without notable activity loss).展开更多
Methyl levulinate(ML)is a promising green candidate for bio-based diesel fuel and fuel additives.An efficient enzyme-catalyzed process to synthesize ML from levulinic acid(LA)in methanol was developed.The catalytic ac...Methyl levulinate(ML)is a promising green candidate for bio-based diesel fuel and fuel additives.An efficient enzyme-catalyzed process to synthesize ML from levulinic acid(LA)in methanol was developed.The catalytic activity of a series of lipases including Novozyme 435(N435),NRTL IM,and 40086 was screened,and the N435 was identified as the optimal biocatalyst for the process.The effects of lipase amount,methyl tert-butyl ether(MTBE)volume,methanol to LA molar ratio,reaction temperature,and magnetic stirrer speed on LA conversion and ML yield were investigated.The response surface methodology was adopted to optimize the enzymatic conversion process,and the model validation experiments showed that the predicted values corresponded well with the experimental values.A LA conversion of 90.1%and a ML yield of 89.8%were achieved under reaction conditions covering:a temperature of 45°C,a reaction time of 4.6 h,a N435 dosage of 26 mg,a methanol to LA molar ratio of 3.6:1,a MTBE volume of 3.85 mL,and a stirrer speed of 150 r/min.The N435 recycling experiment indicated that the lipase activity was quite high after 12 cycles.However,upon using crude LA prepared from carbohydrates as the reactant,the conversion of LA and the ML yield decreased due to impurities existing in the crude LA.展开更多
Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via r...Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via reductive amination/cyclization of levulinic acid(LA)with primary aromatic amines and hydrosilanes(e.g.,PMHS)over Cs F,and a series of N-substituted aryl pyrroles could be obtained in good to excellent yields at 120○C.The mechanism investigation indicates that the reaction proceeds in two steps:the cyclization between amine and LA occurs first to form intermediate 5-methyl-N-alkyl-1,3-dihydro-2H-pyrrolones and their isomeride(B),and then the chemo-and region-selective reduction of intermediates take place to produce the final products.This approach for synthesis of N-substituted aryl pyrroles can be performed under mild and green conditions,which may have promising applications.展开更多
Objective: A series of 4-aryl substituted semicarbazones of levulinic acid (4-oxo pentanoic acid) was designed and synthesized to meet the structural requirements essential for anticonvulsant activity. Methods: All th...Objective: A series of 4-aryl substituted semicarbazones of levulinic acid (4-oxo pentanoic acid) was designed and synthesized to meet the structural requirements essential for anticonvulsant activity. Methods: All the compounds were evaluated for anticonvulsant activity. Anticonvulsant activity was determined after intraperitoneal (i.p.) administration to mice by maximal electroshock (MES) and subcutaneous metrazol (ScMet) induced seizure methods and minimal motor impairment was determined by rotorod test. Results: A majority of the compounds exhibited significant anticonvulsant activity after intraperitoneal administration. In the present study 4-(4'-fluoro phenyl) levulinic acid semicarbazone emerged as the most active molecule, showing broad spectrum of activity with low neurotoxicity. Unsubstituted levulinic acid semicarbazone was found to be inactive in all the screens. Conclusion: The results obtained validate the hypothesis that presence of an aryl group near the semicarbazone moiety is essential for anticonvulsant activity. The results also indicate that the hydrophilic-hydrophobic site can accommodate hydrophilic groups.展开更多
Recently,using biomass waste to extract levulinic acid(LA)has aroused extensive concerns.This research provides a novel LA preparation system with the use of biomass waste in combination with a coal-fired power plant(...Recently,using biomass waste to extract levulinic acid(LA)has aroused extensive concerns.This research provides a novel LA preparation system with the use of biomass waste in combination with a coal-fired power plant(CFPP).As a poly-generation system,it not only produces LA,but also generates heat and electricity to self-sustain the energy consumption.Besides,the material balance,thermodynamics and economics of the system are investigated.Findings indicate that the purity of the refined LA can achieve 99.8%and the energy demand per unit mass of LA is 62.14 MW,which is 36.96 MW lower than the same scenario in previous studies.The total energy efficiency and exergy efficiency for the whole process reach 55.16%and 61.36%.Overall,the system will achieve payback of the initial investment in 3.42 years,and the proposal is projected to have a net present value(NPV)of 1.4722037×10^(8)USD over its 30-year lifespan.展开更多
Based on a systemic analysis for the globa1 burden of disease study from 1990 to 2016,the Global Burden of Diseases(GBD)2016 Alcohol Collaborators reported that alcohol use was a 1eading nisk factor for globa1 disease...Based on a systemic analysis for the globa1 burden of disease study from 1990 to 2016,the Global Burden of Diseases(GBD)2016 Alcohol Collaborators reported that alcohol use was a 1eading nisk factor for globa1 disease burden and caused substantial health loss.However,alcoholic dnink(wines and sakes)contains abundant nutrients,particularly fermentable amino acids denived from grapes and rice.Amino acid nutrition and metabolism is strongly associated with health and preventiom against various diseases.The purpose of this study was to elucidate 40 kinds of free amino acid(FAA)profles in wines and sakes.In addition,the present study also provided the contents of 5-aminolevulinic acid(5-AI A)involved in the vital functionality of mitochondria.FAAs were detected and analyzed by use of an automatic amino acid analyzer.Aromatic amino acid,branched chain amino acid and Fischer ratio were calculated for each beverage.Individua1 FAAs showed significant differences between wines and sakes.Sakes abundantly contained almost all FAAs whereas wines had just a lttle content in some FAAs.Sakse were rich in arginine,glycine,alanine,valine,glutamic acid and leucine,while wines were remarkably nich in proline(Pro).Wines showed increased FAA levels in 6 kinds of variables(4-hydroxyproline,3-methy1 histidine,B-alanine,a-aminobutyric acid,Pro and a.-aminoadipic acid).In functionally characteristic FAAs,both wines and sakes were considerably abundant in y aminobutynic acid and 5-AI A The total amount of aromatic amino acid and branched chain amino acid were markedly higher in sakes than in wines.These results revealed that there were the apparent different characteristics in FAA profiles between wines and sakes.This difference resulted from fermentation process in wines(single fermentation)and sakes(paralle1 double fermentation).Forty kinds of FAA profiles are more usefu1 in investigating characteristics of the taste of wines and sakes.In future,detailed FAA analysis has the potential to find functional nutrients such as 5-AI A,whereas other foods generally contain ittle amount of these FAAs.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22378277)111 Center(B17030)+1 种基金the Basal Research Fund of the Central University(2016SCU04B06)the technical support from the Analysis and Test Center of Sichuan University。
文摘Valorization of renewable cellulose into initial platform chemicals(IPCs)generally suffers from low process efficiency owing to difficult depolymerization of recalcitrant cellulose and troublesome repolymerization of high-reactive intermediates to undesired humins.Herein,we report a double-protective strategy for cellulose depolymerization and orientated conversion to levulinic acid(LA),one of the important IPCs,by in-situ adding protective formaldehyde(HCHO).This approach initiates from the(hemi)acetalation of hydroxyl groups in cellulose with HCHO,causing controllable depolymerization to(hemi)acetalized glucose with increased rate kinetically and a new mechanism of its catalytic conversion to LA via(hemi)acetal-driven direct C1-C2 cleavage.As such,the cellulose-to-LA conversion is protectively proceeded with the repolymerization of reactive intermediates prevented remarkably,leading to an excellent LA yield of 87.3 mol% from high-loading microcrystalline cellulose(15.0 wt% in aqueous phase)in a biphasic solvent containing 2-methyltetrahydrofuran and water.The process efficiency,expressed as space-time yield,is improved by 3.6 fold when compared with a non-protective approach.This work highlights an advance in maximizing the utilization of biomass-derived carbons for high-efficiency production of important IPCs directly from cellulose for future biorefinery.
文摘Conversion of biomass to chemicals or fuels under mild condition is still a challenge. As a platform molecule for chemicals and fuels, levulinic acid （LA） has been prepared by lique-faction of biomass at high pressure. In order to carry out the conversion from wheat straw to LA at atmosphere pressure, continuous extraction of the reactive system by an organic solvent with a higher density than that of water was utilized for degradation of pretreated biomass. Yields of LA were measured by means of gas chromatography-mass spectrometry and nuclear magnetic resonance. The results revealed that a maximum yield of 30.66% of LA can be obtained from wheat straw. In addition, the effects of biomass pretreated conditions on the LA conversion have been studied. The study provides a new route to convert biomass to valuable chemicals at atmosphere pressure.
基金S. Dharne thanks Director, NCL, Pune for permission to workas an M. E. (Chemical Engineering) project trainee
文摘Levulinic acid has been identified as a promising green, biomass-derived platform chemical. n-Butyl levulinate is used as an important intermediate having diverse applications. The present work focuses on the synthesis of n-butyl levulinate by esterification of levulinic acid with n-butanol using heteropolyacid （HPA） supported on acid-treated clay montmorillonite （K10）. 20% （w/w） dodecatungestophosphoric acid （DTPA） supported on K10 was found to be the most efficient catalyst with 97% levulinic acid conversion and 100% selectivity towards n-butyl levulinate. Effects of various process parameters were studied to examine the efficacy of 20% （w/w） DTPA/K10 for optimization of the activity.
基金Supported by the Natural Science Foundation of Henan Educational Committee (No.200510459056).
文摘Levulinic acid is a kind of new green platform chemical with wide application. The kinetics of levulinic acid formation from glucose decomposition at high temperature was investigated. Glucose containing 1%, 3% or 5% H2SO4 was treated at 170℃ or 190℃. For the various experimental conditions assayed, the time-courses of glucose and glucose degradation products (including 5-hydroxymethylfurfural and levulinic acid) were established. These variables were cor-related with the reaction time based on the equations derived from a pseudo-homogeneous, first-order kinetic model, which provided a satisfactory interpretation of the experimental results. The set of kinetic parameters from regression of experimental data provided useful information for understanding the levulinic acid formation mechanism.
文摘Bimetallic nanostructures have attracted great interest as efficient catalyst to enhance activity,selectivity and stability in catalytical conversion.Herein,we report a facile one‐pot carbothermal route to in‐situ controllable synthesize heterogeneous bimetallic Ni3Fe NPs@C nanocatalyst.The X‐ray diffraction,transmission electron microscopy,X‐ray photoelectron spectroscopy and N2 adsorption‐description results reveal that the Ni3Fe alloy nanoparticles are evenly embedded in carbon matrix.The as‐prepared Ni3Fe NPs@C catalyst shows excellent selective hydrogenation catalytic performance toward the conversion of levulinic acid(LA)toγ‐valerolactone(GVL)via both direct hydrogenation(DH)and transfer hydrogenation(TH).In DH of LA,the bimetallic catalyst achieved a 93.8%LA conversion efficiency with a 95.5%GVL selectivity and 38.2 mmol g–1 h–1 GVL productivity(under 130°C,2MPa H2 within 2 h),which are 6 and 40 times in comparison with monometallic Ni NPs@C and Fe NPs@C catalysts,respectively.In addition,the identical catalyst displayed a full conversion of LA with almost 100%GVL selectivity and 167.1 mmol g–1 h–1 GVL productivity at 180°C within 0.5 h in TH of LA.Under optimal reaction conditions,the DH and TH catalytic performance of 500‐Ni3Fe NPs@C(3:1)catalyst for converting LA to GVL is comparable to the state‐of‐the‐art noble‐based catalysts.The demonstrated capability of bimetallic catalyst design approach to introduce dual‐catalytic functionality for DH and TH reactions could be adoptable for other catalysis processes.
基金Supported by the National Natural Science Foundation of China（30940058,31170672）the Natural Science Foundation of Zhejiang Province of China（Y3110025）+1 种基金Key Laboratory for Physical Processing of Agricultural Products（JAPP2010-4）Key Laboratory of Exploitation and Preservation of Coastal Bio-resource（2010F30003）
文摘Levulinic acid（LA） has been identified as a promising green,biomass derived platform chemical.Response surface analysis（RSA） with a four-factor-five-level central composite design（CCD） was applied to optimize the hydrolysis conditions for the conversion of bamboo（Phyllostachys Praecox f.preveynalis） shoot shell（BSS） to LA catalyzed with ionic liquid [C4mim]HSO4.The effects of four main reaction parameters including temperature,time,C[C4mim]HSO4（initial [C4mim]HSO4 concentration） and XBSS（initial BSS intake） on the hydrolysis reaction for yield of LA were analyzed.A quadratic equation model for yield of LA was established and fitted to the data with an R2 of 0.9868,and effects of main factors and their corresponding relationships were obtained with RSA.Model validation and results of CCD showed good correspondence between actual and predicted values.The analysis of variance（ANOVA） of the results indicated that the yield of LA in the range studied was significantly（P＆lt;0.05） affected by the four factors.The optimized reaction conditions were as follows：temperature of 145 ℃,time of 103.8 min,C[C4mim]HSO4 of 0.9 mol.L-1 and XBSS of 2.04%（by mass）,respectively.A high yield [（71±0.41）%（by mol）,triplicate experiment] was obtained at the optimum conditions of temperature of 145 ℃,time of 104 min,C[C4mim]HSO4 of 0.9 mol.L-1 and XBSS of 2%（by mass）,which obtained from the real experiments,concurred with the model prediction [73.8%（by mol） based on available C6 sugars in BSS or 17.9%（by mass） based on the mass of BSS],indicating that the model was adequate for the hydrolysis process.
基金funded by the National Key R&D Program of China (2018YFB1501504)the National Natural Science Foundation of China (Nos. 51776206 and 21878290)+1 种基金the Natural Science Foundation of Guangdong province (2017A030313073)CAS Pioneer Hundred Talents Program
文摘Herein,we reported in situ synthesis of biomass-derived Ni/C catalyst by self-reduction with pomelo peel.Compared with the conventional method, which includes carbonization, activation, impregnation and reduction, the entire preparation process was simplified to two steps, which was more straightforward. This synthesis method was green as Ni/C can be prepared without any additional chemical and the self-reduction process was realized in N2, which can avoid using H2 thus averting some problems such as storage, transportation and safety of H2. Meanwhile, the size and dispersion of Ni particles can be controlled by changing carbonization temperature.The synthesis mechanism of Ni/C catalyst with selfreduction was investigated, which was mainly attributed to the carbon and reducing gas produced during the carbonization process.For the catalytic performance of GVL synthesis, a high yield (94.5%) can be obtained and it exhibited good stability up to 5 cycles without obvious loss of catalytic activity.
基金Supported by the National Key Technology R&D Program of China (2007BAD66B04)
文摘Levulinic acid is considered as a promising green platform chemical derived from biomass.The kinetics of levulinic acid accumulation in the hydrolysis process of wheat straw was investigated in the study.Using dilute sulfuric acid as a catalyst,the kinetic experiments were performed in a temperature range of 190-230°C and an acid concentration range of 1%-5% (by mass) .A simple model of first-order series reactions was developed,which provided a satisfactory interpretation of the experimental results.The kinetics of main intermediates including sugar and 5-hydroxymethylfurfural(5-HMF) were also established.The kinetic parameters provided useful information for understanding the hydrolysis process.
基金financial support from the National Natural Science Foundation of China(21576161,21703133,21802076,and 21962013)the Fundamental Research Funds for the Central Universities(GK202003028)。
文摘Here we exquisitely fabricated Cu/ZrO_(2)-dp catalysts with plentiful Cu-ZrO_(2)interfaces by depositing amorphous ZrO_(2)onto Cu nanoparticles for the hydrogenation of levulinic acid(LA)to y-valerolactone(GVL).With the created plentiful CU-ZrO_(2)interfaces,the optimal catalyst 3 Cu/ZrO_(2)-dp exhibited exceptional catalytic performance under mild reaction conditions,and achieved the highest GVL mass productivity of 266.0 mmol GVL·h^(-1)·g^(-1)Cu,which was 12.5 and 2.3 times of CU/ZrO_(2)catalysts with equivalent Cu loadings prepared by traditional impregnation(3 Cu/ZrO_(2)-im)or co-precipitation(3 Cu/ZrO_(2)-cp).As far as we know,this GVL mass productivity stood at the highest level compared with those obtained using non-noble metal catalysts under similar reaction conditions.By systematic investigation with multiple characterizations,density functional theory(DFT)calculations,and kinetic studies,it was found that interfacial active centers were created at Cu-ZrO_(2)interfaces,which contained oxygen vacancies(O_(v)),negatively charged Cu^(δ)-and partially reduced Zr^(3+)The O_(v) favored the adsorption and activation of LA via its ketone group,while negatively charged Cu^(δ)-was able to enhance heterolysis of H2,which resulted in the formation of H^(+)-Cu^(δ)-and Zr^(3+)-H^(-)active species via hydrogen spillover.Also,plentiful acid sites,which derived from coordinatively unsaturated and defective Zr species,generated at Cu-ZrO_(2)interfaces.With the cooperation of interfacial active centers(Cu^(δ-)-O_(v)-Zr^(3+))and acid sites,the fabricated 3 Cu/ZrO_(2)-dp with plentiful Cu-ZrO_(2)interfaces achieved excellent catalytic performance for the hydrogenation of LA to GVL.Hence,the synergistic catalysis of Cu-ZrO_(2)interfaces provided an effective strategy for designing catalysts with a satisfactory performance for the hydrogenation of LA,which also can be expanded to other hydrodeoxygenation reactions.
基金supported by the Key Area Research&Development Program of Guangdong Province(2020B0101070001)the National Natural Science Foundation of China(21978053,51508547)。
文摘Levulinic acid(LA)is one of the top-12 most promising biomass-based platform chemicals,which has a wide range of applications in a variety of fields.However,separation and purification of LA from aqueous solution or actual hydrolysate continues to be a challenge.Among various downstream separation technologies,liquid-liquid extraction is a low-cost,effective,and simple process to separate LA.The key breakthrough lies in the development of extractants with high extraction efficiency,good hydrophobicity,and low cost.In this work,three hydrophobic deep eutectic solvents(DESs)based on tri-n-octylamine(TOA)as hydrogen bond acceptor(HBA)and alcohols(butanol,2-octanol,and menthol)as hydrogen bond donors(HBDs)were developed to extract LA from aqueous solution.The molar ratios of HBD and HBA,extraction temperature,contact time,solution pH,and initial LA concentration,DES/water volume ratios were systematically investigated.Compared with 2-octanol-TOA and menthol-TOA DES,the butanol-TOA DES exhibited the superior extraction performance for LA,with a maximum extraction efficiency of 95.79±1.4%.Moreover,the solution pH had a great impact on the LA extraction efficiency of butanol-TOA(molar ratio=3:1).It is worth noting that the extraction equilibrium time was less than 0.5 h.More importantly,the butanol-TOA(3:1)DES possesses good extraction abilities for low,medium,and high concentrations of LA.
基金supported by the National Natural Science Foundation of China(21908197)Natural Science Foundation of Zhejiang Province(LY17B030010)。
文摘The hydrogenation of levulinic acid(LA)to c-valerolactone(GVL)by using water as solvent is a crucial process in the production of fine chemicals from biomass.An ultrathin carbon layer coating CoRu bimetallic catalyst supported on silica(CoRu@C/SiO2)is prepared by using tannis-ligated cobalt-ruthenium complex on silica as precursors,and applied for catalyzed synthesis of GVL from LA.Because of the synergistic effect between cobalt and ruthenium,the addition of small amounts of Ru to Co catalysts can increase the catalytic activity in the aqueous hydrogenation of LA.The ultrathin carbon layer covered on the CoRu bimetallic catalyst can greatly reduce the leaching of active metals.The CoRu@C/SiO2 catalyst achieves high stability and is reused up to 5 runs without significant loss of performance in aqueous hydrogenation of levulinic acid.
基金financially supported by the European Union FP7 NMP project NOVACAM (Novel cheap and abundant EU-Japan604319)
文摘A novel pH gradient methodology was used to synthesise a series of Cu–ZrO2 catalysts containing different quantities of Cu and Zr.All of the catalysts were highly selective to the desired product,γ-valerolactone, and are considerably more stable than Cu–ZrO2 catalysts prepared by other co-precipitation methods for this reaction.Characterisation and further investigation of these catalysts by XRD, BET, SEM and XPS provided insight into the nature of the catalytic active site and the physicochemical properties that lead to catalyst stability.We consider the active site to be the interface between Cu/CuOxand ZrOx and that lattice Cu species assist with the dispersion of surface Cu through the promotion of a strong metal support interaction.This enhanced understanding of the active site and roles of lattice and surface Cu will assist with future catalyst design.As such, we conclude that the activity of Cu–ZrO2 catalysts in this reaction is dictated by the quantity of Cu–Zr interface sites.
基金the funding supported by the National Natural Science Foundation of China (21406103)Support plan for Excellent Youth Innovation Team in Shandong Colleges and Universities (2020KJC012)the Foundation of Liaocheng University (318011702)。
文摘The construction of an acid resistant catalyst for synthesis of γ-valerolactone from levulinic acid in aqueous media is an important but highly challenging goal.Herein,an efficient Co@NCNT-800(after 800℃ pyrolysis) catalyst was constructed by confining Co in N-doped carbon nano-tubes(NCNT) from low cost materials by a facile strategy.Combined with the characterization results and control experiments,the in situ formed Co and Co-Ox, but not Co-Nx, proved to be the main synergistic active sites of the catalyst.It was also found that Co species are completely isolated within the bamboo-like NCNT,which could protect the metal nanoparticles from agglomeration and leaching in the strong acid reaction system.The γ-valerolactone yield of no less than 99.9% can be obtained under a relatively mild condition,and the catalytic performance has not been significantly reduced within five cycles.Therefore,this work may pave a way for the design of robust non-noble catalyst,and has potential for the production of γ-valerolactone from biomass in large-scale industries.
文摘Levulinic acid(LA)is a platform biorefinery chemical from biomass which can be converted to green solvents,plasticizers,polymer precursors,biobased cleaning agents,fuels and fuel additives.This study assessed the potential of SnCl_(2)-based mixed acid systems as catalyst in the hydrothermal conversion of microcrystalline cellulose to levulinic acid.Maximum LAyield of 36.2 mol%was achieved using 0.2 M SnCl_(2) concentration at test conditions of 3 h,180℃ and 1%w/v cellulose loading.To reduce precipitate formation and further improve LA yield,the strategy employed was to combine SnCl_(2)(a Lewis acid)with conventional mineral acids(Bronsted acids).Evaluation of the catalytic performance of SnCl_(2)-HCl,SnCl_(2)-H_(2)SO_(4),SnCl_(2)-HNO_(3),and SnCl_(2)-H_(3)PO_(4)(1:1 molar ratio,0.2 M total acid concentration)were done with highest LA yield of 47.0 mol%obtained using the SnCl_(2)-HCl system at same test conditions.Response surface methodology optimization employing Box-Behnken design generated a quadratic model with a high coefficient of determination(r2)of 0.964.A maximum LA yield of 63.5 mol%can be achieved at 0.17 M catalyst concentration,198℃,and 5.15 h reaction time.Rate constants were estimated using nonlinear regression,while activation energies were determined using Arrhenius equation.Cellulose hydrolysis was determined to be the rate-limiting step in the overall process.Low activation energy of 63.3 kJ/mol for glucose dehydration to hydroxymethylfurfural supports the action of SnCl_(2) as Lewis acid in the mixed-acid system.LA yield simulations for plug flow reactor(PFR)and continuous stirred tank reactor(CSTR)were done suggesting a similar PFR-CSTR configuration with the established Biofine process.Lastly,a reaction scheme was presented to explain the synergy between SnCl_(2) and HCl in LA production from cellulose.
基金financially supported by the National Key Research and Development Program of China(2018YFB1105100)the National Natural Science Foundation of China(51974339 and 51674270)the funding from Science Foundation of China University of Petroleum,Beijing(24620188JC005)。
文摘Developing a highly active and durable non-noble metal catalyst for aqueous-phase levulinic acid(LA)hydrogenation to g-valerolactone(GVL)is an appealing yet challenging task.Herein,we report well-dispersed Co nanoparticles(NPs)embedded in nitrogen-doped mesoporous carbon nanofibers as an efficient catalyst for aqueous-phase LA hydrogenation to GVL.The Co zeolitic imidazolate framework(ZIF-67)nanocrystals were anchored on the sodium dodecyl sulfate modified wipe fiber(WF-S),yielding one-dimensional(1-D)structured composite(ZIF-67/WF-S).Subsequently,Co NPs were uniformly embedded in nitrogen-doped mesoporous carbon nanofibers(Co^(R)NC/SMCNF)through a pyrolysis-reduction strategy using ZIF-67/WF-S as the precursor.Benefiting from introducing modified wipe fiber WF-S to enhance the dispersion of Co NPs,and Co^(0) with Co-N_xdual active sites,the resulting Co^(R)NC/SMCNF catalyst shows brilliant catalytic activity(206 h^(-1) turnover frequency).Additionally,the strong metal-support interactions greatly inhibited the Co NPs from aggregation and leaching from the mesoporous carbon nanofibers,and thus increasing the reusability of the Co^(R)NC/SMCNF catalyst(reusable nine times without notable activity loss).
基金This work was supported by the Natural Science Foundation of China(U1904122)the Program of Processing and Efficient Utilization of Biomass Resources of Henan Center for Outstanding Overseas Scientists(GZS2018004).
文摘Methyl levulinate(ML)is a promising green candidate for bio-based diesel fuel and fuel additives.An efficient enzyme-catalyzed process to synthesize ML from levulinic acid(LA)in methanol was developed.The catalytic activity of a series of lipases including Novozyme 435(N435),NRTL IM,and 40086 was screened,and the N435 was identified as the optimal biocatalyst for the process.The effects of lipase amount,methyl tert-butyl ether(MTBE)volume,methanol to LA molar ratio,reaction temperature,and magnetic stirrer speed on LA conversion and ML yield were investigated.The response surface methodology was adopted to optimize the enzymatic conversion process,and the model validation experiments showed that the predicted values corresponded well with the experimental values.A LA conversion of 90.1%and a ML yield of 89.8%were achieved under reaction conditions covering:a temperature of 45°C,a reaction time of 4.6 h,a N435 dosage of 26 mg,a methanol to LA molar ratio of 3.6:1,a MTBE volume of 3.85 mL,and a stirrer speed of 150 r/min.The N435 recycling experiment indicated that the lipase activity was quite high after 12 cycles.However,upon using crude LA prepared from carbohydrates as the reactant,the conversion of LA and the ML yield decreased due to impurities existing in the crude LA.
基金supported by Chinese Academy of Sciences,China(Grant No.QYZDY-SSW-SLH013-2)Henan Normal University,China。
文摘Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via reductive amination/cyclization of levulinic acid(LA)with primary aromatic amines and hydrosilanes(e.g.,PMHS)over Cs F,and a series of N-substituted aryl pyrroles could be obtained in good to excellent yields at 120○C.The mechanism investigation indicates that the reaction proceeds in two steps:the cyclization between amine and LA occurs first to form intermediate 5-methyl-N-alkyl-1,3-dihydro-2H-pyrrolones and their isomeride(B),and then the chemo-and region-selective reduction of intermediates take place to produce the final products.This approach for synthesis of N-substituted aryl pyrroles can be performed under mild and green conditions,which may have promising applications.
文摘Objective: A series of 4-aryl substituted semicarbazones of levulinic acid (4-oxo pentanoic acid) was designed and synthesized to meet the structural requirements essential for anticonvulsant activity. Methods: All the compounds were evaluated for anticonvulsant activity. Anticonvulsant activity was determined after intraperitoneal (i.p.) administration to mice by maximal electroshock (MES) and subcutaneous metrazol (ScMet) induced seizure methods and minimal motor impairment was determined by rotorod test. Results: A majority of the compounds exhibited significant anticonvulsant activity after intraperitoneal administration. In the present study 4-(4'-fluoro phenyl) levulinic acid semicarbazone emerged as the most active molecule, showing broad spectrum of activity with low neurotoxicity. Unsubstituted levulinic acid semicarbazone was found to be inactive in all the screens. Conclusion: The results obtained validate the hypothesis that presence of an aryl group near the semicarbazone moiety is essential for anticonvulsant activity. The results also indicate that the hydrophilic-hydrophobic site can accommodate hydrophilic groups.
基金supported by the National Nature Science Fund of China(No.52276006 and No.52106008)。
文摘Recently,using biomass waste to extract levulinic acid(LA)has aroused extensive concerns.This research provides a novel LA preparation system with the use of biomass waste in combination with a coal-fired power plant(CFPP).As a poly-generation system,it not only produces LA,but also generates heat and electricity to self-sustain the energy consumption.Besides,the material balance,thermodynamics and economics of the system are investigated.Findings indicate that the purity of the refined LA can achieve 99.8%and the energy demand per unit mass of LA is 62.14 MW,which is 36.96 MW lower than the same scenario in previous studies.The total energy efficiency and exergy efficiency for the whole process reach 55.16%and 61.36%.Overall,the system will achieve payback of the initial investment in 3.42 years,and the proposal is projected to have a net present value(NPV)of 1.4722037×10^(8)USD over its 30-year lifespan.
文摘Based on a systemic analysis for the globa1 burden of disease study from 1990 to 2016,the Global Burden of Diseases(GBD)2016 Alcohol Collaborators reported that alcohol use was a 1eading nisk factor for globa1 disease burden and caused substantial health loss.However,alcoholic dnink(wines and sakes)contains abundant nutrients,particularly fermentable amino acids denived from grapes and rice.Amino acid nutrition and metabolism is strongly associated with health and preventiom against various diseases.The purpose of this study was to elucidate 40 kinds of free amino acid(FAA)profles in wines and sakes.In addition,the present study also provided the contents of 5-aminolevulinic acid(5-AI A)involved in the vital functionality of mitochondria.FAAs were detected and analyzed by use of an automatic amino acid analyzer.Aromatic amino acid,branched chain amino acid and Fischer ratio were calculated for each beverage.Individua1 FAAs showed significant differences between wines and sakes.Sakes abundantly contained almost all FAAs whereas wines had just a lttle content in some FAAs.Sakse were rich in arginine,glycine,alanine,valine,glutamic acid and leucine,while wines were remarkably nich in proline(Pro).Wines showed increased FAA levels in 6 kinds of variables(4-hydroxyproline,3-methy1 histidine,B-alanine,a-aminobutyric acid,Pro and a.-aminoadipic acid).In functionally characteristic FAAs,both wines and sakes were considerably abundant in y aminobutynic acid and 5-AI A The total amount of aromatic amino acid and branched chain amino acid were markedly higher in sakes than in wines.These results revealed that there were the apparent different characteristics in FAA profiles between wines and sakes.This difference resulted from fermentation process in wines(single fermentation)and sakes(paralle1 double fermentation).Forty kinds of FAA profiles are more usefu1 in investigating characteristics of the taste of wines and sakes.In future,detailed FAA analysis has the potential to find functional nutrients such as 5-AI A,whereas other foods generally contain ittle amount of these FAAs.
