Wang Z.,Beijing University of Chemical Technology |
Li X.,Beijing University of Chemical Technology |
Zhen S.,Shanghai Tobacco Group Corporation |
Li X.,Tsinghua University |
And 2 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2013
Chlorogenic acid and its two structural components, quinic acid and caffeic acid, were pyrolyzed under reaction conditions simulating the typical pyrolysis conditions inside a burning cigarette. Major phenolic products from pyrolysis of the three acids were quantified and compared to evaluate the respective contribution of the quinic and caffeic acid moieties to the overall phenolic yield in chlorogenic acid pyrolysis. The results show that the most prominent phenolic product of chlorogenic acid is catechol, followed in order by phenol, hydroquinone, and alkylcatechols. Among these phenolics, catechol and alkylcatechols are formed mainly from the caffeic acid moiety of chlorogenic acid, while phenol and hydroquinone are produced predominantly from the quinic acid moiety. The quinic acid moiety can thus contribute more than 40 % of the overall phenolic yields in chlorogenic acid pyrolysis (0.54 mol mol-1 chlorogenic acid pyrolyzed at 600 C). Because considerable amounts of free quinic acid and its derivatives exist in tobacco, the results of this study indicate that quinic acid can be an important source of phenolic compounds, especially hydroquinone and phenol, in tobacco smoke. © 2013 Akadémiai Kiadó, Budapest, Hungary.
Li X.,Tsinghua University |
Li X.,Shanghai Tobacco Group Corporation |
Li J.,Tsinghua University |
Zhou G.,Tsinghua University |
And 7 more authors.
Applied Catalysis A: General | Year: 2014
This study investigated catalytic fast pyrolysis (CFP) of a series of biomass (cellulose, lignin, and pine wood), plastics (low-density polyethylene (LDPE), polyethylene (PP), and polystyrene (PS)), and their mixtures with ZSM-5 zeolite. Co-feeding of cellulose with LDPE (mixing ratios of 4-1) produced much higher petrochemical (aromatics and olefins) yields (52.1-55.6 C%) and lower solid (coke/char) yields (22.6-10.9 C%) than those expected if there were no chemical interactions between the two feedstocks in co-feed CFP (37.4-39.2 C% and 25.0-15.9 C% for petrochemicals and solid, respectively, calculated by linear addition of the corresponding yields determined in CFP of cellulose and LDPE individually). This result indicates that cellulose and LDPE have a significant synergy that enhances the production of valuable petrochemicals and decreases the undesired coke in CFP. Similar synergy was also observed in co-feed CFP of pine wood and LDPE mixtures (mixing ratio of 2), which produced 49.5 C% petrochemicals and 19.5 C% solid residue. In comparison, CFP of pine wood and LDPE individually produced only 31.6 C% and 41.0 C% petrochemicals and 46.5 C% and 6.74 C% solid, respectively. This synergy, however, was less pronounced for the other combinations of biomass and plastics (cellulose/PP, cellulose/PS, and lignin/LDPE) tested in this study. The results suggest that the interactions between the primary pyrolysis products of cellulose and LDPE, especially Diels-Alder reactions of cellulose-derived furans with LDPE-derived linear α-olefins, play an important role in the synergy for petrochemical production and coke reduction in co-feed CFP. Co-feeding LDPE thus has great potential in improving the performance of CFP of natural lignocellulosic biomass, which usually contains a significant fraction (40-50 wt.%) of cellulose component. © 2014 Elsevier B.V.
PubMed | Tsinghua University and Shanghai Tobacco Group Corporation
Type: Journal Article | Journal: Molecules (Basel, Switzerland) | Year: 2014
A new prenylated indole diketopiperazine alkaloid, cristatumin F (1), and four known metabolites, echinulin (2), dehydroechinulin (3), neoechinulin A (4) and variecolorin O (5), were isolated from the crude extract of the fungus Eurotium cristatum. The structure of 1 was elucidated primarily by NMR and MS methods. The absolute configuration of 1 was assigned using Marfeys method applied to its acid hydrolyzate. Cristatumin F (1) showed modest radical scavenging activity against DPPH radicals, and exhibited marginal attenuation of 3T3L1 pre-adipocytes.
Liu X.,Shanghai Tobacco Group Corporation |
Zhang J.,Shanghai Tobacco Group Corporation |
Zhang C.,Shanghai Tobacco Group Corporation |
Yang B.,Jiangxi Provincial Maternal and Child Health Hospital |
And 3 more authors.
Toxicology Research | Year: 2016
4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is considered to be the most carcinogenic of the four tobacco-specific nitrosamines (TSNAs) and it needs to be metabolically activated to exert its carcinogenic effect on humans. For the simultaneous intake of NNK and other compounds with similar molecular structures in the context of tobacco smoke, whether (R,S)-N-nitrosoanatabine (NAT), (R,S)-N-nitrosoanabasine (NAB) and nicotine contribute to the inhibitory potency of the cytochrome P450 (CYP) enzyme-catalyzed NNK metabolism or not needs to be investigated. In the in vitro study, 4-oxo-4-(3-pyridyl) butanal (OPB), 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB) and 4-oxo-4-(3-pyridyl) butanoic acid (OPBA) were established as the products of the CYP2A13-catalyzed NNK metabolism and the kinetic parameters were calculated from the Michaelis-Menten equation. Addition of NAT, NAB or nicotine resulted in a competitive inhibition for the NNK metabolism catalyzed by CYP2A13. The inhibition constant Ki values were calculated to be 0.21 μM (NAT), 0.23 μM (NAB) and 8.51 μM (nicotine) for OPB formation; 0.71 μM (NAT), 0.87 μM (NAB) and 25.01 μM (nicotine) for HPB formation and 0.36 μM (NAT), 0.50 μM (NAB) and 6.57 μM (nicotine) for OPBA formation, respectively. In addition, the study of the transformation of the three metabolites revealed OPB was not only an end product but also an intermediate product of the CYP2A13-catalyzed NNK metabolism. These results suggest that structurally similar tobacco constituents with weak or no carcinogenicity influence the metabolic activation of NNK, which interferes with its carcinogenicity to some extent. © The Royal Society of Chemistry 2016.
Chen D.,Tianjin University |
Xu Y.,Tianjin University |
Li Q.,Tianjin University |
Yu L.,Shanghai Tobacco Group Corporation |
And 2 more authors.
Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering | Year: 2016
To improve the resolution capability and accuracy of routine Raman spectroscopy, two-dimensional correlation spectroscopy (2DCOS) was proposed for detection of olive oil adulteration. Two-dimensional correlation Raman spectroscopy can effectively feature the olive components and their functional group changes which are decided by the content and the type of the adulterated oils. These changes can facilitate olive adulteration analysis. By combining multi-scale modeling (MM) with N-way partial least square (NPLS), information is extracted from 2DCOS and then a quantitative model of high robustness and precision is constructed. The results show that the model can improve the accuracy and the robustness of the common analytical model significantly, not only extracting new information from the olive signals, but also making it simpler to get reliable results, which provides a promising tool for spectral analysis of complex system. © 2016, Tianjin University. All right reserved.
Sha Y.,Shanghai Tobacco Group Corporation |
Huang D.,Fudan University |
Zheng S.,Shanghai Tobacco Group Corporation |
Liu B.,Shanghai Tobacco Group Corporation |
Deng C.,Fudan University
Analytical Methods | Year: 2013
Phenol is a mainstream cigarette smoke constituent and has been classified as a main toxic component directly related to environmental and health issues. Analysis of phenol in mainstream cigarette smoke is of great importance. In this work, microwave-assisted headspace solid-phase microextraction (HS-SPME) was developed for the fast analysis of phenol in a cigarette pad. Analyte in a Cambridge cigarette pad, activated by a short period of microwave irradiation, was headspace extracted by SPME and analyzed by GC-MS. Extraction conditions such as microwave irradiation time, SPME fiber coating, adsorption time and desorption time were investigated and optimized to achieve the best effect. The method was validated through the investigation of linearity, detection limit, recovery and precision. The linearity was in a wide range of 0.005-1 μg mL-1 with a correlation coefficient R2 = 0.999. The limit of detection was as low as 0.5 ng mL-1, and acceptable recovery and RSD values of 86.5% and 11.5% were achieved. The proposed method was successfully applied to the analysis of phenol in cigarette pad samples. The experimental results have demonstrated that microwave-assisted HS-SPME followed by GC-MS was a rapid, efficient and convenient method for the determination of phenol in tobacco products. © 2013 The Royal Society of Chemistry.
Wang Y.,Tongji University |
Wang Y.,Shanghai Tobacco Group Corporation Ltd |
Liu M.,Tongji University |
Zhu Y.,Tongji University |
And 4 more authors.
Talanta | Year: 2016
Tobacco related free radicals (TFRs) in the cigarette smoke are specific classes of hazardous compounds that merit concern. In this study, we developed a hybrid method to identify TFRs directly based on ultra-performance convergence chromatography with a quadrupole time-of-flight mass spectrometry (UPCC-QTOF MS) combined spin trapping technique. The short-lived TFRs were stabilized successfully in situ through spin trapping procedure and UPCC was applied to facilitate efficient separation of complex derivative products. Coupling of orthogonal partial least squares discriminant analysis (OPLS-DA), UPCC-QTOF MS system enabled us to identify specific potential TFRs with exact chemical formula. Moreover, computational stimulations have been carried out to evaluate the optimized stability of TFRs. This work is a successful demonstration for the application of an advanced hyphenated technique for separation of TFRs with short detection time (less than 7 min) and high throughput. © 2016 Elsevier B.V.
Zhao M.,South China University of Technology |
Wang H.,South China University of Technology |
Wang H.,Shanghai Tobacco Group Corporation |
Yang B.,CAS South China Botanical Garden |
Tao H.,China Tobacco Industry Co.
Food Chemistry | Year: 2010
Chlorogenic acid is an important bioactive compound which is unstable under ambient conditions. In this work, chlorogenic acid was extracted from tobacco leaf and purified by high performance liquid chromatography. β-Cyclodextrin (β-CD) was used to form inclusion complex with chlorogenic acid. Analyses of differential scanning calorimeter (DSC) and 1H nuclear magnetic resonance (NMR) spectroscopy confirmed the formation of inclusion complex and quinic acid moiety was included within the β-CD cavity. A blue shift of ca. 2 nm for chlorogenic acid was detected after inclusion. The storage stability of chlorogenic acid was apparently improved by measurement of absorbance change during 20 weeks. Through determinations of DPPH radical scavenging and antimicrobial activities, no significant difference was observed between chlorogenic acid and its complex. Therefore, construction of β-CD inclusion complex was helpful for the application of chlorogenic acid. © 2009 Elsevier Ltd. All rights reserved.
Shi J.,Shanghai Tobacco Group Corporation |
Liu B.,Shanghai Tobacco Group Corporation |
Xie W.,Shanghai Tobacco Group Corporation
Chinese Journal of Chromatography (Se Pu) | Year: 2010
The mid-point restrictor, known as the key spare part of multidimensional gas chromatography (MDGC), was modified and applied in the determination of benzo [a] pyrene in cigarette smoke. The graphite restrictor was replaced by a 0. 25 mm i. d. fused silica open tubular and the two-hole graphite ferrule was replaced by a press-fit glass Y-splitter to improve the stability of retention time on the 1 st dimensional column and eliminate the carry-over effects of graphite. The cigarette samples were prepared as follows: The mainstream cigarette smoke collected on Cambridge pad was extracted with cyclohexane, then the extractant was analyzed by heart cut MDGC-mass spectrometry (MS) directly with benzo [a] pyrene-dl2 as internal standard. The method was proved to be simple, sensitive, fast and reliable with good linearity (linear range of 1. 47-29. 4 μg/L, r 2 of 0. 999 9), reproducibility (relative standard deviation (RSD) of 1. 94%), recovery (90. 74% - 101. 86%) and low quantitative and qualitative detection limits. Moreover, the amount of benzo [a] pyrene in the 2R4F Kentucky reference cigarette smoke obtained by this method was close to that reported in literature.
PubMed | Shanghai Tobacco Group Corporation
Type: Journal Article | Journal: Se pu = Chinese journal of chromatography | Year: 2010
The mid-point restrictor, known as the key spare part of multidimensional gas chromatography (MDGC), was modified and applied in the determination of benzo[a] pyrene in cigarette smoke. The graphite restrictor was replaced by a 0.25 mm i.d. fused silica open tubular and the two-hole graphite ferrule was replaced by a press-fit glass Y-splitter to improve the stability of retention time on the 1st dimensional column and eliminate the carry-over effects of graphite. The cigarette samples were prepared as follows: The mainstream cigarette smoke collected on Cambridge pad was extracted with cyclohexane, then the extractant was analyzed by heart cut MDGC-mass spectrometry (MS) directly with benzo [ a] pyrene-d12 as internal standard. The method was proved to be simple, sensitive, fast and reliable with good linearity (linear range of 1.47-29.4 microg/L, r2 of 0.9999), reproducibility (relative standard deviation (RSD) of 1.94%), recovery (90.74%-101.86%) and low quantitative and qualitative detection limits. Moreover, the amount of benzo [a] pyrene in the 2R4F Kentucky reference cigarette smoke obtained by this method was close to that reported in literature.