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1. Synthesis of aryl-substituted 2-methoxyphenol derivatives from maltol-derived oxidopyrylium cycloadducts through an acid-mediated ring contraction cascade

Author:
Bejcek, Lauren P.; Murelli, Ryan P.
Source:
Chemical communications 2020 v.56 no.21 pp. 3203-3205
ISSN:
1364-548X
Subject:
guaiacol,   etc   ; alkynes; boron; chemical reactions; maltol; methane; sulfonates;     Show all 7 Subjects
Abstract:
... Oxidopyrylium cycloadducts derived from maltol and aryl acetylenes undergo acid-mediated rearrangements to generate aryl-substituted 2-methoxyphenol (guaiacol) derivatives. Specifically, the cycloadducts react with boron trichloride to form 2-methoxy-5-arylphenol molecules, and with methane sulfonate to form 2-methoxy-4-aryl-6-methylphenol molecules. ...
DOI:
10.1039/c9cc09213g

2. Perceptual interactions and characterisation of odour quality of binary mixtures of volatile phenols and 2-isobutyl-3-methoxypyrazine in a red wine matrix

Author:
McKay, Marianne; Bauer, Florian F.; Panzeri, Valeria; Buica, Astrid
Source:
Journal of wine research 2020 v.31 no.1 pp. 49-66
ISSN:
1469-9672
Subject:
guaiacol,   etc   ; leather; o-cresol; odors; pyrazines; red wines; sweet peppers;     Show all 7 Subjects
Abstract:
... The qualitative perceptual interactions of single and binary mixtures of four compounds: guaiacol (‘burnt/smoky’), o-cresol (‘phenolic/tar’), 4-ethylphenol (4-EP, ‘leather/barnyard’), and 2-isobutyl-3-methoxypyrazine (IBMP, ‘green pepper/herbaceous’), were studied in a partially de-aromatised red wine matrix. Using Descriptive Analysis, each compound was characterised individually by a trained pan ...
DOI:
10.1080/09571264.2020.1723069

3. Influence of reaction conditions on solvolysis of organosolv lignin using water and green organic co-solvents as reaction medium

Author:
Hashmi, Syed Farhan; Meriö-Talvio, Heidi; Ruuttunen, Kyösti; Sixta, Herbert
Source:
Fuel processing technology 2020 v.197 pp. 106200
ISSN:
0378-3820
Subject:
guaiacol,   etc   ; catalytic activity; ethanol; lignin; methanol; solvents; solvolysis; sulfur; temperature;     Show all 9 Subjects
Abstract:
... This study investigated the non-catalyzed solvolysis of sulphur free organosolv lignin using mixtures of organic solvents (methanol, ethanol and 2-methyltetrahydrofuran) and water with emphasis on the novel biphasic 2-methyltetrahydrofuran (2-MTHF)/water reaction medium. The effect of co-solvents, co-solvent-to-water ratio and temperature were studied. 2-MTHF proved to be effective co-solvent with ...
DOI:
10.1016/j.fuproc.2019.106200

4. Laccase: addressing the ambivalence associated with the calculation of enzyme activity

Author:
Agrawal, Komal; Verma, Pradeep
Source:
3 Biotech 2019 v.9 no.10 pp. 365
ISSN:
2190-572X
Subject:
guaiacol,   etc   ; enzyme activity; laccase; oxygen;     Show all 4 Subjects
Abstract:
... Laccase (benzenediol: oxygen oxidoreductase) a unique multi-copper oxidase enzyme has been studied rigorously since its identification. However, there is ambivalence associated with various aspects of laccase, e.g., assay conditions and calculations. Our aim was to minimize its ambivalence, thus, total of five formulas (F1–F5) were used to determine laccase activity of white and blue laccase. In c ...
DOI:
10.1007/s13205-019-1895-1
PubMed:
31588389
PubMed Central:
PMC6754822

5. Production of phenolic chemicals from hydrolysis lignin via catalytic fast pyrolysis

Author:
Paysepar, Hooman; Venkateswara Rao, Kasanneni Tirumala; Yuan, Zhongshun; Shui, Hengfu; Xu, Chunbao
Source:
Journal of analytical and applied pyrolysis 2020 v.149 pp. 104842
ISSN:
0165-2370
Subject:
guaiacol,   etc   ; acidity; biofuels; catalysts; catalytic activity; crystal structure; hydrolysis; lignin; molecular weight; pyrolysis; temperature; zeolites;     Show all 12 Subjects
Abstract:
... Catalytic fast pyrolysis of hydrolysis lignin was investigated in a drop-tube fixed bed reactor at different temperatures ranging between 400–800 °C using zeolite X as a catalyst for the production of phenolic chemicals. The yield of low molecular weight monomeric phenolics increased considerably while increasing the pyrolysis temperature from 400 °C to 450 °C, but decreased with further increasin ...
DOI:
10.1016/j.jaap.2020.104842

6. Evidence for cross-polymerization between the biomass-derived furans and phenolics

Author:
Sun, Kai; Zhang, Lijun; Xu, Qing; Zhang, Zhanming; Shao, Yuewen; Dong, Dehua; Gao, Guanggang; Liu, Qing; Wang, Shuang; Hu, Xun
Source:
Renewable energy 2020 v.154 pp. 517-531
ISSN:
0960-1481
Subject:
guaiacol,   etc   ; biofuels; carbon; furfural; furfuryl alcohol; polymerization; polymers; sugars; sulfuric acid; thermal stability; vanillin;     Show all 11 Subjects
Abstract:
... The high tendency of bio-oil towards polymerization is one of the key challenges in hydrotreatment of bio-oil for production of bio-fuels. However, such properties of bio-oil could be used to produce carbon materials, but the mechanism for the polymerization has not been clarified. Bio-oil contains sugars, derivatives of sugars (i.e. furans et al.), phenolic monomers and oligomers. Among of them, ...
DOI:
10.1016/j.renene.2020.03.030

7. Experimental study on composition evolution of biomass pyrolysis vapors with condensing temperature in a vertical tubular condenser

Author:
Wang, Chu; Sun, Mengchao; Deng, Jingjing; Zhu, Xifeng
Source:
Bioresource technology 2020 v.307 pp. 123252
ISSN:
0960-8524
Subject:
guaiacol,   etc   ; acetic acid; biofuels; biomass; furfural; hydraulic flumes; moieties; pyrolysis; quantitative analysis; temperature; vapors; walnut hulls;     Show all 12 Subjects
Abstract:
... The experiments on bio-oil recovery in a vertical tubular condenser with two flumes were conducted for speculating the componential distribution of walnut shell pyrolysis vapors during condensation. Bio-oil elements and functional groups from different locations of condenser were compared with each other. Aromatic H and H in phenolic OH were concentrated in the top and middle bio-oil and their per ...
DOI:
10.1016/j.biortech.2020.123252

8. Catalytic reforming of palm kernel shell microwave pyrolysis vapors over iron-loaded activated carbon: Enhanced production of phenol and hydrogen

Author:
An, Yang; Tahmasebi, Arash; Zhao, Xiaohui; Matamba, Tawanda; Yu, Jianglong
Source:
Bioresource technology 2020 v.306 pp. 123111
ISSN:
0960-8524
Subject:
guaiacol,   etc   ; activated carbon; catalysts; catalytic activity; hydrogen; iron; models; palm kernels; phenol; pyrolysis; vapors;     Show all 11 Subjects
Abstract:
... This study addresses the in-situ microwave catalytic reforming of volatile matter from palm kernel shell (PKS) over iron-loaded activated carbon (Fe/AC) catalysts. The impacts of catalyst composition on the secondary gas-phase reactions and distribution of products were studied at 500 °C. It was found that the Fe/AC catalyst promoted the yield of light gases. Using the 1%-Fe/AC catalyst, the yield ...
DOI:
10.1016/j.biortech.2020.123111

9. Combination of zingerone and dihydroartemisinin presented synergistic antimalarial activity against Plasmodium berghei infection in BALB/c mice as in vivo model

Author:
Ounjaijean, Sakaewan; Somsak, Voravuth
Source:
Parasitology international 2020 v.76 pp. 102088
ISSN:
1383-5769
Subject:
guaiacol,   etc   ; Plasmodium berghei; acute oral toxicity; artemisinin; death; guidelines; malaria; models; mortality; parasitemia; subtropics;     Show all 11 Subjects
Abstract:
... Malaria is a global health problem leading to the death of 435,000 cases in tropical and sub-tropical zones. Spread and emergence of increasing resistance to the antimalarial drugs are the major challenges in the control of malaria. Therefore, searching for alternative antimalarial drugs is urgently needed, and combination treatment preferred as an approach to address this. This study aimed to eva ...
DOI:
10.1016/j.parint.2020.102088

10. Gas-phase hydrodeoxygenation of guaiacol over Ni-based HUSY zeolite catalysts under atmospheric H2 pressure

Author:
Yujian, Wu; Xiwei, Xu; Xudong, Fan; Jiamin, Wang; Wu, Yujian; Xu, Xiwei; Sun, Yan; Jiang, Enchen; Fan, Xudong; Tu, Ren; Wang, Jiamin
Source:
Renewable energy 2020 v.152 pp. 1380-1390
ISSN:
0960-1481
Subject:
guaiacol,   etc   ; active sites; biofuels; catalysts; gases; hydrogen; hydrogenation; hydroquinone; iron; nickel; quinones; value added; zeolites;     Show all 13 Subjects
Abstract:
... Hydrodeoxygenation (HDO) is considered as one of the most promising routes to upgrade bio-oil for high value-added chemicals. In the study, the gas-phase HDO of guaiacol in atmosphere and 350 °C over Ni-based catalysts modified by Fe, Ga, Ce, La, or Sm on HUSY zeolite support was carried on. The effect of promotors, bimetallic/monometallic catalysts and Ni loading on HDO activity was investigated. ...
DOI:
10.1016/j.renene.2020.01.117

11. Development of a method to measure laccase activity on methoxyphenolic food ingredients and isomers

Author:
Manzano-Nicolas, Jesus; Marin-Iniesta, Fulgencio; Taboada-Rodriguez, Amaury; Garcia-Canovas, Francisco; Tudela-Serrano, Jose; Muñoz-Muñoz, Jose Luis
Source:
International journal of biological macromolecules 2020 v.151 pp. 1099-1107
ISSN:
0141-8130
Subject:
guaiacol,   etc   ; Coriolus versicolor; ascorbic acid; catalytic activity; enzyme activity; free radicals; ingredients; isomers; laccase; oxidation;     Show all 10 Subjects
Abstract:
... We studied the laccase-catalysed oxygenation of methoxyphenolic food ingredients, such as 2-methoxyphenol (guaiacol) and 2,6-dimethoxyphenol (syringol), isomers such as 3- and 4-methoxyphenol, and 2,3-, 3,4- and 3,5-dimethoxyphenol. These methoxyphenolic substrates generate unstable free radicals, which leads to the erroneous determination of steady state rates. The addition of small quantities of ...
DOI:
10.1016/j.ijbiomac.2019.10.152

12. Characterization of important sulfur and nitrogen compounds in Lang baijiu by application of gas chromatography-olfactometry, flame photometric detection, nitrogen phosphorus detector and odor activity value

Author:
Zhu, JianCai; Niu, YunWei; Xiao, ZuoBing
Source:
Food research international 2020 v.131 pp. 109001
ISSN:
0963-9969
Subject:
guaiacol,   etc   ; acetates; gas chromatography-mass spectrometry; nitrogen; odor compounds; odors; phosphorus; photometry; pyrazines; sulfur; synergism; thiols;     Show all 12 Subjects
Abstract:
... The volatile compounds in three Lang baijiu (“Honghualangshi, Y1”, “Langjiulangge, Y2”, and “Laolangjiu, Y3”) were identified by gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry (GC–MS), flame photometric detection (FPD), and nitrogen phosphorus detector (NPD) with the aid of stir bar sorptive extraction (SBSE). The results showed that a total of 60, 62, and 61 compound ...
DOI:
10.1016/j.foodres.2020.109001

13. Enhanced Acid-Catalyzed Lignin Depolymerization in a Continuous Reactor with Stable Activity

Author:
Nandiwale, Kakasaheb Y.; Danby, Andrew M.; Ramanathan, Anand; Chaudhari, Raghunath V.; Motagamwala, Ali Hussain; Dumesic, James A.; Subramaniam, Bala
Source:
ACS sustainable chemistry & engineering 2020 v.8 no.10 pp. 4096-4106
ISSN:
2168-0485
Subject:
guaiacol,   etc   ; batch systems; catalysts; catalytic activity; depolymerization; lactones; lignin; methanol; palladium; porous media; wood;     Show all 11 Subjects
Abstract:
... A continuous process to depolymerize maple wood lignin dissolved in γ-valerolactone (GVL) to monomeric phenols is demonstrated in a stirred reactor using a mesoporous Zr-KIT-5 catalyst. The yield of identified aromatic monomers is stable for 18 h of continuous operation and reaches 7 wt % when the lignin feed is subjected to thermo-solvolytic pretreatment. Without the thermal pretreatment, the mon ...
DOI:
10.1021/acssuschemeng.9b06556

14. Deep eutectic mixture membrane-based microextraction: HPLC-FLD determination of phenols in smoked food samples

Author:
Shishov, Andrey; Gagarionova, Svetlana; Bulatov, Andrey
Source:
Food chemistry 2020 v.314 pp. 126097
ISSN:
0308-8146
Subject:
guaiacol,   etc   ; chemical species; choline chloride; detection limit; eugenol; hydrogen bonding; hydrophilicity; microextraction; o-cresol; p-cresol; phenol; smoked foods;     Show all 12 Subjects
Abstract:
... A novel approach for effective sample pretreatment of food was developed. This approach was based on in situ deep eutectic mixtures formation between analytes (hydrogen bond donors) and choline chloride (a hydrogen bond acceptor) supported in a hydrophilic porous membrane. By this action, the analytes were extracted and retained into the hydrophilic porous membrane. Finally, the hydrophilic porous ...
DOI:
10.1016/j.foodchem.2019.126097

15. Effect of the type of wood used for ageing on the volatile composition of Pedro Ximénez sweet wine

Author:
Herrera, Pablo; Durán‐Guerrero, Enrique; Sánchez‐Guillén, Manuel M; García‐Moreno, M Valme; Guillén, Dominico A; Barroso, Carmelo G; Castro, Remedios
Source:
Journal of the science of food and agriculture 2020 v.100 no.6 pp. 2512-2521
ISSN:
0022-5142
Subject:
guaiacol,   etc   ; Castanea; acetates; barrels; detection limit; gas chromatography-mass spectrometry; lactones; toasting; volatile compounds; wine aging; wines; wood;     Show all 12 Subjects
Abstract:
... BACKGROUND: The present study investigated the volatile composition of a Pedro Ximénez sweet wine that had been aged in barrels made of different types of wood (Spanish oak, French oak, American oak and chestnut) and subjected to different degrees of toasting (medium toasting and intense toasting). The analyses were carried out using stir bar sorptive extraction gas chromatography–mass spectrometr ...
DOI:
10.1002/jsfa.10276

16. Cardanol- and Guaiacol-Sourced Solution-Processable Green Small Molecule-Based Organic Solar Cells

Author:
Rajkumar, Barla; Khanam, Lubna; Koukaras, Emmanuel N.; Sharma, Ganesh D.; Singh, Samarendra P.; Lochab, Bimlesh
Source:
ACS sustainable chemistry & engineering 2020 v.8 no.15 pp. 5891-5902
ISSN:
2168-0485
Subject:
guaiacol,   etc   ; bio-feedstocks; clean energy; density functional theory; infrastructure; renewable resources; semiconductors; solar cells; thermal stability; thiophene;     Show all 10 Subjects
Abstract:
... An environmentally compatible organic solar cell (OSC) has potential to build a global clean energy infrastructure for the world. However, much less attention has been focused on the structures sourced from greener origins to enhance the sustainability aspect of these devices. Herein, we report a rational design, synthesis, and characterization of donor (D)-acceptor (A)-based green organic small m ...
DOI:
10.1021/acssuschemeng.9b07600

17. Effects of NaOH on the catalytic pyrolysis of lignin/HZSM-5 to prepare aromatic hydrocarbons

Author:
Wu, Jilai; Chang, Guozhang; Li, Xiao; Li, Jinshuai; Guo, Qingjie
Source:
Journal of analytical and applied pyrolysis 2020 v.146 pp. 104775
ISSN:
0165-2370
Subject:
guaiacol,   etc   ; aromatic hydrocarbons; catalytic activity; hydrogen; lignin; models; moieties; pyrolysis; sodium; sodium carbonate; sodium hydroxide; temperature; waste liquors;     Show all 13 Subjects
Abstract:
... The pyrolysis of alkali lignin in black liquor to prepare bio-chemical is attracting increasing attention. In addition to alkali lignin, black liquor also contains a large amount of sodium salts (e.g., NaOH and Na₂CO₃). In the present study, the fast pyrolysis of lignin was carried out in a fixed bed reactor. The effect of NaOH on the preparation of aromatic hydrocarbons by catalytic pyrolysis of ...
DOI:
10.1016/j.jaap.2020.104775

18. Steam reforming of guaiacol over Ni/SiO2 catalyst modified with basic oxides: Impacts of alkalinity on properties of coke

Author:
Zhang, Zhanming; Zhang, Xiao; Zhang, Lijun; Wang, Yiran; Li, Xianglin; Zhang, Shu; Liu, Qing; Wei, Tao; Gao, Guanggang; Hu, Xun
Source:
Energy conversion and management 2020 v.205 pp. 112301
ISSN:
0196-8904
Subject:
guaiacol,   etc   ; adsorption; alkalinity; biomass gasification; carbon nanotubes; catalysts; catalytic activity; magnesium; models; nickel; polymers; silica; sodium; steam; thermal stability;     Show all 15 Subjects
Abstract:
... Alkalinity is an important parameter affecting adsorption and evolution of reaction substrates in steam reforming reactions. In this study, steam reforming of guaiacol, a model compounds in the volatiles in gasification of biomass, over Ni/SiO₂ modified with Na, Mg or La was investigated. The results showed that the strong alkalinity induced by Na or Mg addition to Ni/SiO₂ led to remarkably decrea ...
DOI:
10.1016/j.enconman.2019.112301

19. Factors affecting Alicyclobacillus acidoterrestris growth and guaiacol production and controlling apple juice spoilage by lauric arginate and ϵ-polylysine

Author:
Hu, Xiaohuan; Huang, En; Barringer, Sheryl A.; Yousef, Ahmed E.
Source:
Lebensmittel-Wissenschaft + [i.e. und] Technologie 2020 v.119 pp. 108883
ISSN:
0023-6438
Subject:
guaiacol,   etc   ; Alicyclobacillus acidoterrestris; apple juice; bacteria; bacterial growth; glucose; mass spectrometry; off odors; pH; spoilage; spores; starch; temperature; vanillin; yeasts;     Show all 15 Subjects
Abstract:
... Growth of Alicyclobacillus acidoterrestris in fruit juices has been associated with the release of off-odor compounds, such as guaiacol. Guaiacol release was quantified using Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) and method's minimum detection level was 3.6 ppb. The amount of guaiacol released was dependent on the amount of vanillin added to the medium. Sucrose-supplemented yeast star ...
DOI:
10.1016/j.lwt.2019.108883

20. Investigation of olfactory interactions of low levels of five off-flavour causing compounds in a red wine matrix

Author:
McKay, Marianne; Bauer, Florian F.; Panzeri, Valeria; Buica, Astrid
Source:
Food research international 2020 v.128 pp. 108878
ISSN:
0963-9969
Subject:
guaiacol,   etc   ; cork; cultivars; leather; o-cresol; off flavors; pyrazines; red wines; response surface methodology; sensation; sweet peppers; taint; winemaking;     Show all 13 Subjects
Abstract:
... The qualitative sensory perception of individual and of complex mixtures of five compounds, guaiacol (‘burnt note’), o-cresol (‘phenolic/tar’), 4-ethylphenol (4-EP, ‘leather/barnyard’), 2-iso-butyl-3-methoxypyrazine (IBMP, ‘green pepper/herbaceous’), and 2,4,6-trichloroanisole (TCA, ‘cork taint/ mouldy’) were tested in a partially de-aromatised red wine matrix using descriptive analysis by a train ...
DOI:
10.1016/j.foodres.2019.108878