Biomass Conversion and Biorefinery
·
2019
·Vol. 10
·期 2
·277-287
·
IF 2.326
Shi Ning,Liu Qiying,Cen Hu,Ju Rongmei,He Xiong,Ma Longlong
Humins are undesired solids formed during the hydrothermal degradation of carbohydrates. In order to reveal the mechanism of formation of humins, we studied the degradation behavior of 11 model compounds including carbohydrates and furfural derivatives, within water and various pure organic solvents as reaction media. All the studied carbohydrates could generate solid humins in both water and studied organic solvents except ethanol, while the furfural derivatives could generate solid humins in only water. The results could be explained by regarding the formed α-carbonyl aldehydes and α,β-unsaturated aldehydes as primary precursors for formation of humins. Furfural derivatives could generate chain α-carbonyl aldehydes (for example, 6-hydroxy-2,5-dioxohexanal from 5-hydroxymethylfurfural and 2-oxopentanedial from furfural) through hydrolytic ring opening reaction; thus, water is essential for these furfural derivatives to generate humins. As for carbohydrates, they could generate α-carbonyl aldehydes and α,β-unsaturated aldehydes through simple step of β-elimination in all solvents; thus, they could form humins in both water and studied organic solvents except ethanol. Ethanol could react with α-carbonyl aldehydes by acetalization; thus, the condensation between α-carbonyl aldehydes was suppressed in ethanol, leading to few humins formation from carbohydrates. Based on the above analysis, we proposed that the formed α-carbonyl aldehydes and α,β-unsaturated aldehydes should be the primary precursor of humins.
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SENSORS
·
2019
·Vol. 19
·期 3
·674
·
IF 3.031
Hong Zhai,Yunfeng Bai,Jun Qin,Feng Feng
A novel colorimetric and ratiometric fluorescence sensor was constructed by using carbon quantum dots (CQDs) and o-diaminobenzene (ODB). Unlike ODB by itself, ODB oxide (oxODB) not only emits fluorescence, but also produces ultraviolet (UV) absorption. Therefore, on the basis of the potential optical properties of ODB, glucose oxidase (Gox) and horseradish peroxidase (HRP) were introduced into a CQDs–ODB system for the quantitative oxidation of ODB. When glucose is present, it is oxidized by oxygen under the catalytic action of its oxidase to form hydrogen peroxide. Hydrogen peroxide is a strong oxidant that can rapidly oxidize ODB through the catalysis of horseradish peroxidase. oxODB can cause changes in the fluorescence ratio (I550/I446) and absorbance ratio (A/A0). At the same time, the color of the detection solution can also change under sunlight and ultraviolet lamps. Therefore, glucose can be quantitatively detected by ratiometric fluorescence and colorimetry simultaneously, and semi-quantitatively detected by observing the colors with sunlight and ultraviolet lamps of 365 nm. This increases not only the convenience but also the accuracy of detection. In addition, this sensor has good selectivity and can be used for the determination of glucose in serum, providing a new idea for the development of blood glucose sensors.Keywords:dual-mode sensor;carbon quantum dots;o-diaminobenzene;glucose
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LWT-FOOD SCIENCE AND TECHNOLOGY
·
2019
·
IF 3.714
Hafiz Muhammad Saleem Akhtar,Mohamed Abdin,Yahya Saud Hamed,Wei Wang,Guijie Chen,Dan Chen,Chunxu Chen,Wei Li,Shanza Mukhtar,Xiaoxiong Zeng
In the present study, polysaccharides (CHPS) were prepared from chickpea hulls by hot water extraction and ethanol precipitation, and the physicochemical, functional, thermal and structural characteristics of CHPS were investigated. The results revealed that CHPS was comprised of mannose , rhamnose, galacturonic acid, glucose, galactose , xylose and arabinose with molar percentages of 2.16, 2.96, 42.17, 9.87, 23.15, 6.29 and 13.38%, respectively. Functional analysis demonstrated that CHPS had good fat-binding, foaming and emulsifying properties. CHPS also exhibited good thermal stability. According to X-ray spectrum, CHPS was a semi-crystalline in nature which was also confirmed from scanning electron microscopic analysis. The solid-state spectrum of 13 C NMR reflected that CHPS were complex and heterogeneous polymers. Moreover, CHPS showed favorable inhibitory activity against α-amylase. These findings indicated that CHPS could be exploited as a hypoglycemic agent or multi-purpose additive in pharmaceuticals, cosmetics and food industries.
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CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Chun-Qian Zhang,Xia Chen,Kan Ding
Dioscorea opposita Thunb. is widely used as functional foods and traditional Chinese medicine in China for its activity of regulating function of spleen and stomach. Polysaccharides may contribute to the function of regulation. To investigate structure features and bioactivities of polysaccharides from D. opposita, the rhizome of D. opposita was extracted with boiling water, yielding crude polysaccharides DOP. A novel polysaccharide named DOP0.1-S-1 was isolated from DOP by further purification. The average molecular weight of DOP0.1-S-1 was 10,000 Da and the range was around 12,000 –1,200 Da. The carbohydrate content of DOP0.1-S-1 was 100% and no protein was detected. The monosaccharide analysis showed that DOP0.1-S-1 was mostly composed of galactose. Methylation and NMR spectra analysis indicated that DOP0.1-S-1 was a 1,4-β-galactan. Bioactivity test showed that DOP0.1-S-1 could promote the growth of B. thetaiotaomicron and B. ovatus and produce the short-chain fatty acids during the utilization of the polysaccharide.
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CARBON
·
2019
·
IF 7.466
Lei Xie,Zhe Wang,Jinrong Liu,Yutong Gong,Shanjun Mao,Guofeng Lü,Xiao Ma,Lili Yu,Yong Wang
The easy hydrothermal method is a potential candidate for the preparation of carbohydrate-derived hierarchically porous polymers (HPPs) and carbons (HPCs). However, owing to the uncontrolled reaction rate and the weak affinity between precursors and soft templates, the synthesis of HPPs and HPCs with tunable properties through this method remains a great challenge. Here we develop a kinetics-controlled soft-template strategy to enable the preparation of a series of HPPs and HPCs with variable porous and morphological structures from diverse building blocks. By simply controlling the reaction kinetics with the change of acid concentration, flower-like and layered materials assembled from ordered mesoporous plates, and materials with adjustable mesopores and macropores aggregated from nanoparticles with different sizes, could be generated. Moreover, Pt nanoparticles were in situ encapsulated inside HPPs. With the advantages of both Pt nanoparticles and HPCs, the as made Pt@HPCs catalyst realized the size-selective hydrogenation of various alkenes .
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ENERGY & FUELS
·
2019
·
IF 3.021
Ning Shi,Qiying Liu,Xiong He,Gui Wang,Ni Chen,Jiayu Peng,Longlong Ma
Hydrochars are solid byproducts formed during the liquid-phase biorefinery process and could be used to generate functional carbonaceous materials, but the detailed molecular structure and the formation mechanism are still unclear. Herein, the formation of hydrochars from liquid-phase carbonization of biomass-derived compounds including glucose, fructose, xylose, ribose, dihydroxyacetone (DHA), 5-hydroxymethylfurfural (HMF), furfural (FF), and pyruvaldehyde (PRV) in water and inert polar organic solvents ethyl acetate (EAC) and tetrahydrofuran (THF) was studied. The carbohydrates were found to generate hydrochars in both water and the organic solvents, while the HMF and FF could generate hydrochars only in water. The α-carbonyl aldehydes, including PRV, 3-deoxyglucosone, and 2,5-dioxo-6-hydroxyhexanal (DHH), formed during the decomposition of carbohydrates were proposed to be the key primary precursors for hydrochar formation. The molecular structures of the hydrochars were characterized by elemental analysis, Fourier transform infrared analysis, and solid-state 13C NMR analysis to confirm that the molecular formula of the hydrochars all could be approximately expressed as (C3H2O)n, and the molecular structures of the hydrochars all consisted of polyaromatic hydrocarbon, phenolic, furanic, and aliphatic framents and a small amount of carbonyl/carboxyl groups. The presence of the polyaromatic hydrocarbon and phenolic fragments in the hydrochars suggested that aldol condensation played a critical role for hydrochar formation. By regarding the aldol condensation of α-carbonyl aldehydes as the initial step for hydrochar formation, we deduced the polymerization routes of these α-carbonyl aldehydes and found that the α-carbonyl aldehydes all could undergo aldol condensation followed by acetal cyclization and etherification to form polymers (C3H2O)n rich in furanic framework or undergo aldol condensation followed by a 1,2-hydride shift, intramolecular aldol condensation, and dehydration to generate polymers (C3H2O)n rich in the phenolic framework. One molecular structure containing polyaromatic hydrocarbon, phenolic, furanic, and aliphatic fragments is proposed for the hydrochars.
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Energy Science & Engineering
·
2019
·Vol. 7
·期 5
·2237-2246
·
IF 2.893
Yuan Zhao,Hao Xu,Kaifeng Lu,Yang Qu,Lingjun Zhu,Shurong Wang
In this study, the most abundant C5 carbohydrate unit in biomass, namely xylose, was chosen as the feedstock, and its hydrothermal conversion for furfural production was carried out in a green and renewable solvent system composed of water and butanone, in order to study the role of FeCl 3 and [bmim]Cl of ionic liquid catalyst in the conversion process of xylose. A key intermediate named xylulose from Lewis acid-catalyzed xylose isomerization was quantified. It was concluded that appropriate content of FeCl 3 and [bmim]Cl favored the isomerization-dehydration reaction path along which xylose was converted into furfural, while excessive amount of either component would result in side reactions leading to furfural consumption at long reaction times. By comparison between ionic liquid catalysts that had different active metal sites, xylose conversion and furfural yields were found to increase when the Lewis acidity of the metal ions became stronger. Moreover, chlorometallate anions with better catalytic performance than the original neutral salts were formed during catalyst preparation, and in this way, the xylose conversion and furfural formation were further promoted. Finally, the optimized ionic liquid catalyst produced a highest furfural yield of 75% and xylose conversion of 99% at 140°C.
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CHROMATOGRAPHIA
·
2018
·Vol. 81
·期 4
·657-667
·
IF 1.401
Yu Guo-Wei,Cheng Qiang,Nie Jing,Wang Xia-Jun,Wang Peng,Li Zu-Guang,Lee Maw-Rong
Abstract Deep eutectic solvent has been gaining much attention in recent years due to its various novel properties. The present study develops a novel microwave-assisted hydrodistillation method based on pretreatment using deep eutectic solvent, for the extraction of essential oil (EO) from dry fruits of Amomum kravanh , Amomum tsaoko, and Amomum villosum , respectively. The process is optimized by single-factor experiments taking the improvement in the essential oil yield of A. kravanh as the target. The results indicate that using the reaction product of choline chloride and ethylene glycol as the deep eutectic solvent with 7:1 of mass ratio to fruit powder, the optimal conditions are (1) pretreatment stage: 500 W of microwave power, 50 °C of temperature, and 7 min of duration; (2) fast heating stage: 600 W of microwave power, 110 °C of temperature, and 5 min of duration; (3) hydrodistillation stage: 300 W of microwave power, 110 °C of temperature, and 30 min of duration. Under these conditions, the EO yields of A. kravanh , A. tsaoko, and A. villosum are 3.64, 2.16, and 1.62%, respectively. The EOs are analyzed by gas chromatography–mass spectrometry, with totally 63 compounds identified. In most cases, the new method brings about more identified compounds than the traditional methods. Moreover, the relative contents of hydrocarbons in most essential oils are improved by applying the new method. Thus, the approach based on deep eutectic solvent has been proved superior in the enhancement of essential oil production. Graphical abstract
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NPG Asia Materials
·
2018
·Vol. 10
·期 4
·177-189
·
IF 7.208
Gao Zhong Feng,Sann Ei Ei,Lou Xiaoding,Liu Renyi,Dai Jun,Zuo Xiaolei,Xia Fan,Jiang Lei
Herein, we demonstrate a contact angle (CA)-based naked-eye point-of-care testing platform with rapid pH-responsive superwettability that can switch between superhydrophilic and superhydrophobic properties for quantitative biosensing. The CA of the droplet on the pH-responsive surface approached ~0° at pH 1 and conversely reached 161.4° ± 6.2° at pH 13. We realized the sensitive detection of the pH, urea, and glucose by monitoring the changes in the CA. The traditional invasive diagnosis of diabetes causes pain and brings the risk of infections, such as acquired immune deficiency syndrome (AIDS), hepatitis B, hepatitis C, and syphilis, to the user. To address this issue, we implemented a method for the non-invasive diagnosis of diabetes in human saliva and urine, which avoided the significant drawbacks mentioned above. The accuracy of this method was demonstrated by comparing the results with those from commercial glucometers and theoretical calculations. Interestingly, we successfully monitored glucose levels in sweat before, during, and after cycling. The sensing performance was barely influenced by the temperature, elevation, and droplet color, illustrating promise for expansion to hundreds of millions of potential customers, especially those with color blindness or color weakness. Given its low cost, lack of instruments, and rapid response (within 1 s), this strategy might overcome the limitations of the mechanical stability and durability of superwettable materials and thus might extend the industrial-scale application of bioinspired superwettable systems.
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FOOD CHEMISTRY
·
2018
·
IF 4.946
Lei Wang,Bin Zhang,Jie Xiao,Qiang Huang,Chao Li,Xiong Fu
Water-soluble polysaccharides (RTFP) were extracted from Rosa roxburghii Tratt fruit by hot water method. The physicochemical, functional, and hypoglycemic properties of RTFP were investigated. The results revealed that RTFP mainly contained carbohydrates (63.79 ± 0.73%, g/g), uronic acids (14.8 ± 0.06%, g/g), and proteins (4.10 ± 0.58%, g/g). RTFP was composed of arabinose, galactose, glucose, mannose, xylose, and fucose with molar percentages of 33.8, 37.3, 20.7, 1.74, 3.43, and 2.95%, respectively. Functional analyses indicated that RTFP had good oil-holding capacity, foaming properties, and emulsifying capacity. The rheological results showed that RTFP exhibited typical shear-thinning behavior and viscoelastic properties influenced by sample concentration, temperature and inorganic salt. Additionally, RTFP exhibited favorable inhibitory activities against α-glucosidase in a mixed inhibition type, and against α-amylase in an uncompetitive inhibition type. These results suggest that RTFP can be exploited as a multi-functional additive or hypoglycemic agent in foods, pharmaceuticals and cosmetics.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Yang Cheng,Luthuli Sibusiso,Lingfeng Hou,Huijing Jiang,Peichao Chen,Xu Zhang,Mingjiang Wu,Haibin Tong
Diabetes is a complicated endocrine and metabolic disorder, which has become an epidemic health issue worldwide. Fucoidan is extensively distributed in the brown algae and several marine invertebrates exhibiting diverse biological activities. In the present study, the physicochemical property of Sargassum fusiforme fucoidan (SFF) and its effects on streptozotocin (STZ)-induced diabetic mice and gut microbiota were investigated. Diabetes mice not only showed abnormal blood glucose, but also accompanied by multiple symptoms, such as gradual emaciation, decreased body weight, increased food and water intake. Compared with diabetic mice after 6-week treatment, administration of SFF significantly decreased the fasting blood glucose, diet and water intake. Furthermore, SFF attenuated the pathological change in the heart and liver, improved the liver function, and suppressed oxidative stress in STZ-induced diabetic mice. Simultaneously, SFF significantly altered the gut microbiota in the faeces of diabetic mice, decreased the relative abundances of the diabetes-related intestinal bacteria, which is a potential mechanism for relieving the symptoms of diabetes. Therefore, SFF might be considered as one of the promising complementary and alternative medicines for the management of diabetes mellitus in future.
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TALANTA
·
2019
·
IF 4.916
Yaxue Jia,Shucheng Sun,Xiujun Cui,Xiaohong Wang,Li Yang
We show that vanadomolybdophosphoric heteropoly acid (H 5 PMo 10 V 2 O 40 , PMoV 2 ), one of the polyoxometalates (POMs), presents peroxidase-like activity that can catalyze the luminol/H 2 O 2 reaction to generate chemiluminescence (CL) emission. Based on this foundation, we report an enzyme-free luminol/H 2 O 2 /PMoV 2 CL system that can be utilized for the ultrasensitive detection of H 2 O 2 . The CL intensity exhibits good linear dependence on H 2 O 2 concentration in a wide range up to 5000 nM with a limit-of-detection of 5 nM. The method was successfully used for the determination of glucose in human serum. Our study paves the way for the application of functional POM materials in a variety of biosensing assays, such as the determination of cholesterol, uric acid , lactate, etc., in which H 2 O 2 is a product of oxidoreductase enzymes.
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