Cembrane-type diterpenoids are recognized for their medicinal significance. The phytochemical investigation of Nicotiana tabacum L. led to the isolation of Nicocembranoside A (1), a novel cembrane glycoside, represents the ninth naturally occurring cembrane glycoside and the first isolated from N. tabacum leaves. The structure of 1 was elucidated through comprehensive spectroscopic analyses, including 1D (1H, 13C NMR) and 2D NMR (COSY, HSQC, HMBC, ROESY), complemented by HRESIMS and biosynthetic precedence. Additionally, seven known compounds were also isolated and characterized. Preliminary evaluation demonstrated 1 exhibits neuroprotective effect against glutamate-induced cytotoxicity in PC12 cells at 10 mu M.

A new style of low temperature combustion cigarettes was prepared by implanting a thermally conductive cellulose/coper composite rod (TCCR) in the cut tobacco section, so as to explore the application feasibility at the low temperature environment. The burning temperature of the cigarettes was investigated by thermocouple to study the influence of the implanted TCCRs. The emission of conventional components and seven harmful components in mainstream smoke were also carried out to study the effect of TCCRs. The results show that implantation of TCCRs could reduce the burning temperature of cigarettes effectively, which decreased over 100 °C. In compared with conventional cigarettes, the amount of nicotine and nicotine-freed dry particulate matter (NFDPM) in mainstream smoke of TCCRs implanted cigarettes changed little, while the release of harmful components such as CO, HCN, NNK and phenol decreased over 20%. Moreover, the TCCRs, which made of copper paper with 2 g / 18 g weight ratio of pulp and copper, and 5 mm interval perforating, could reduce the burning temperature of cigarettes by 145 °C and the hazard index by 2.01.

为研究卷烟制丝工艺中关键工序烟丝游离氨基酸的变化规律,在SIROX增温增湿和滚筒烘丝两个关键工序间进行在线取样,测定了3个批次9个样品中的氨基酸含量(质量分数),并比较了3个工序点烟丝游离氨基酸含量变化趋势.结果表明,加工前后烟丝的氨基酸含量和组成均发生了明显变化.方差分析显示,烟丝经过SIROX增温增湿工序处理,其丙氨酸、甘氨酸、缬氨酸、亮氨酸、丝氨酸和苏氨酸6种氨基酸含量显著增加(P<0.05),增加幅度3.9％～8.3％;而经过滚筒烘丝处理后,烟丝缬氨酸、亮氨酸、丝氨酸、苯丙氨酸和谷氨酸5种氨基酸含量显著降低(P<0.05),降低幅度介于1.7％～3.0％.主成分分析表明,根据9个样品游离氨基酸的分布情况,同一工序点的烟丝可聚为一类,不同工序点的烟丝能够较好地区分开.

该文研究了制丝线增温增湿和滚筒烘丝工序加工对叶丝香味组分的影响,采用溶剂超声萃取前处理结合GC-MS法测定叶丝的香味组分,并对SIROX增温增湿工序和滚筒烘丝工序前后叶丝香味组分的相对含量进行了分析,比较了工序前后、工序间香味组分的变化趋势.结果 显示:①经SIROX增温增湿工序加工后,乙酸、苯甲醇等18种组分相对含量减少,糠醇、2,4-二羟基-2,5-二甲基-3(2H)-呋喃-3-酮等6种组分相对含量增加;②经滚筒烘丝工序加工后,乙酸、麦芽酚等14种组分相对含量减少,糠醇、糠醛等6种组分相对含量增加;③经增温增湿及滚筒烘丝两工序后,乙酸、2,3-丁二醇等23种组分相对含量减少,糠醇、2,4-二羟基-2,5-二甲基-3(2H)-呋喃-3-酮等4种组分相对含量增加;④两工序间的温度、湿度剧烈变化,使叶丝内部组分发生了美拉德反应、降解反应、挥发等,香味组分经两个工序后发生了一系列显著变化.该研究对提升卷烟产品质量、优化工艺参数、开发高质量产品具有重要意义.

为快速测定卷烟中总氮的含量,采用元素分析法和连续流动分析法对700个卷烟样品分别检测其总氮含量,运用元素分析法测定数据建立总氮预测模型,并通过111个卷烟样品对所建模型进行验证实验.结果显示,模型总氮预测值与连续流动分析法总氮测定值的相对偏差在4％ 以内,通过配对样品T检验进一步验证,在显著性水平大于0.05时,两种方法不存在显著性差异,表明应用元素分析法测定含量数据建立的模型可快速预测卷烟中总氮的含量,适合用于卷烟样品中连续流动分析法总氮含量的预测,为卷烟品质评价提供了一种新的方法.

通过对广东地区卷烟消费者自然状态下吸烟行为的街头调查,分析其吸烟行为特点.结果显示,广东地区消费者的吸烟行为具有以下规律性:(1)消费者抽吸卷烟时,极少出现滤嘴通风孔被完全封闭的情形,而通风孔50％ 封闭的情形也不足34％.(2)局促环境下广东消费者单支烟的吸入烟气总量,会远高于其放松状态下的烟气吸入量.(3)街头调查结果验证了访谈调查数据可在一定程度上反映消费者的吸烟行为.(4)广东省内卷烟消费者的吸烟行为表现为"快(高抽吸频率)且浅(低抽吸容量)",其单支烟吸入烟气总量远远低于欧美消费者的.(5)马萨诸塞方法设定的机器抽吸卷烟条件与广东地区卷烟消费者的习惯性吸烟行为最为接近,而WHO官方方法则显著高估广东消费者烟气吸入量的平均水平.

为尝试开发出低温燃烧型卷烟,本研究采用金属粉末烧结法制成不同类型导热棒植入卷烟,并比较了由此引起的燃烧温度、有害物释放量的变化情况.结果显示:(1)以烧结棒替代金属棒,可减少导热棒植入卷烟时带来的安全风险,并降低燃烧锥温度100℃以上,使低温燃烧卷烟设计成为可能.(2)导热棒的制备,压制烧结法优于松装烧结法,复合铜粉为原料优于铝粉和纯铜粉.(3)低温燃烧卷烟的危害性指数显著低于常规卷烟,如植入Cu:Fe=20:4导热棒的卷烟,其危害性指数降低了2.52,降幅达到了29.8％.

A new thermally conductive copper paper was prepared with cellulose pulp and ultrafine copper powder in a traditional paper making process. The thermal conductivity of the copper paper was studied in different weight ratios, and the surface morphology was observed by scanning electron microscopy (SEM). The results showed that the addition of copper powder enhanced the thermal conductivity of copper paper distinctly, with a maximum of up to 0.560 w.m(-1).K-1 in the weight ratio of pulp/copper of 1:12, which was an increase of 143% compared with the paper without copper. Scanning electron microscopy images showed that copper papers consisted of copper powder particles distributing compactly on the fiber surface. The tensile index of copper paper decreased compared with the paper without filler. A calendaring process was used to improve the combination between copper particles and fibers and to enhance the thermal conductivity of copper paper.

In order to screen habitual smoking behavior of cigarette consumers in Guangdong Province, the behavior parameters from different smokers smoking different types of cigarettes were obtained via an in-situ smoking behavior recorder. The results showed that the smoking behavior of smokers had following patterns:1)A compensatory puffing behavior was noted in smokers who smoked unfamiliar cigarette samples, except for those who were used to smoke low tar cigarettes. 2)With the decrease in labelled tar delivery of their habitual cigarettes, both the puff number and puff volume took by the smokers were gradually reduced, and the total volume of smoke inhaled was decreased greatly for a single cigarette. Therefore the total volume of smoke inhaled by low tar cigarette smokers were found to be lower than that of medium/high tar cigarette smokers. 3)The smokers of low tar, low nicotine cigarettes and blended-type cigarettes had similar smoking behavior with less puff numbers, i.e., short puff durations, high flow rates and low puff volume; and the total volume of smoke inhaled by them for a single cigarette was lower. 4)There were differences in smoking behavior among different types of smokers, the total volume of smoke inhaled by female smokers, low age smokers and medium smoking degree smokers for a single cigarette total was among the lowest.

In order to effectively evaluate quality consistency of cigarette, multi-feature analysis was performed on physical indexes, chemical components of cut tobacco and mainstream smoke indexes. Similarity analysis (SA) was applied in evaluating cigarette quality and consistency of same brand. Results showed that the proposed SA method could test quality fluctuation of cigarettes effectively, which were in line with sensory results. PCA was successfully applied to classify and distinguish four kinds of cigarette brands. SA and PCA based on multi-feature could evaluate quality consistency of cigarette products in a quantitative and objective manner.

Elemental analysis was developed to determine sulfur content. Results showed that organic and inorganic standard samples produce values very close to theoretical values, with deviation less than 1%. Standard recovery rate ranged from 95.3%to 98.9%, RSD ranged from 0.11%to 2.22%. The elemental analysis method was accurate and suitable for the determination of sulfur in tobacco and tobacco products.

Thermogravimetry and pyrolysis behavior of tobacco leaves from various stalk positions of light-flavor and strong-flavor were investigated using thermo-gravimetric analysis coupled with Fourier transform infrared spectroscopy (TG-FTIR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Results showed that leaf tobacco was pyrolyzed more thoroughly under air atmosphere than under nitrogen atmosphere. Differences in pyrolysis behaviors among stages under nitrogen atmosphere were observed. More alkali aroma components, isovaleric acid, benzoate and carotenoid degradation products were determined in strong-flavor tobacco leaves while more Maillard reaction products were found in light-flavor tobacco leaves. Upper-middle tobacco plant leaves had more aroma components than lower-middle tobacco plant leaves.

By adjusting the weighting coefficients of each portion's peak area of chromatograph data, the cluster analysis chart was established basing on the results of sensory evaluation of a reblended tobacco flavoring to monitor its quality variation during storage with the chromatographic data. The established regressive matrix model could be used to evaluate the quality status of the reblended tobacco flavorings stored for different periods.

The total nitrogens in tobacco samples were determined by an element analyzer, the recoveries of this method for different types of tobacco leaves and cigarette samples were investigated, the results were compared with those determined by continuous flow analyzer. The results showed that: 1) There was no significant difference between the detection results by elemental analysis method and continuous flow analysis method; 2) The repeatability and reproducibility of elemental analysis method were good, and the recovery of standard addition ranged from 95% to 103%.

The aroma components in secondarily formulated flavor blocks of different storage durations were analyzed by solvent extraction combining with GC/MS.The changes of these components were evaluated by principal component analysis and t-test.The results showed that the aroma components in the samples could be satisfactorily extracted by dichloride methane with good repeatability.The results of GC/MS analytical data processed by principal component analysis and t-test reflected the variation of the samples as a whole and significance of changes of individual aroma component during storage,which provided reference for the evaluation of the stability and storage duration of secondarily formulated flavor blocks.

Sample of tobacco was pyrolyzed under temperatures of 400,600,800,1 000,1 200 ℃,and the alkenes released was determined by GC-MS.It was shown that the amount of hazardous alkenes released was found to increase gradually with the increase of pyrolytic temperature;the maximum amount of flavorous alkenes released was attained at 600 ℃.Therefore,burning cigarettes at 600 ℃ can enhance the notes of fresh aroma and reduce hazardous alkenes.

Benzene,toluene,xylene and styrene generated from pyrolyzed tobacco leaves were determined by a pyrolysis-GC-MS system coupled with an adsorption trap.The effects of different pyrolysis conditions on the generation of benzene and associated volatile compounds were investigated,including the final pyrolysis temperatures(600 ℃~1000 ℃),retention times of final pyrolysis temperatures(0 s-20 s),retention times of initial pyrolysis temperature(0 s~20 s)and heating rates(30 ℃/s~500 ℃/s).The final pyrolysis temperature showed the highest influence on the releasing of benzene and associated volatile compounds,followed by the heating rate of the temperature.The retention time at the initial or final pyrolysis temperatures had no significant effects on the releasing of benzene and associated volatile compounds.The optimized pyrolysis conditions were determined for detection of the benzene and associated volatile compounds by using pyrolysis-GC-MS.

The thermogravimetry and pyrolysis behavior of cigarettes were investigated by thermo-gravimetric analysis coupled with Fourier transform infrared spectroscopy(TG-FTIR) and pyrolysis-gas chromatrography/mass spectrometry(Py-GC/MS).The curves of TG and derivative thermogravimetry(DTG) of cigarettes were determined,and the releasing amounts of H2O,CO2,CO,NH3 and CH4 produced by pyrolysis under different atmospheres were also compared.The results showed that the atmosphere had an obvious effect on the pyrolysis of cigarettes.The thermal decomposition of cigarettes were mainly taken place between 200-500℃ and became slowly after 700℃ under nitrogen and air atmosphere.The solid residue in nitrogen at final was about 25%,while in air was approximately 7-9%.The qualitative and semi-quantitative analyses of the pyrolysis products of cigarettes were performed by Py-GC/MS at 600,700,800,900,1000℃ respectively.The effects of pyrolysis temperature and atmosphere on the pyrolysis behavior for the selected pyrolysates in smoke were discussed.

A quantitative analytical method for triacetin in plasticizer was developed by using Gas chromatography (GC) with a FID detector and a polar capillary.The sample was dissolved in ethanol and trans-anethole was used as internal standard.Results showed that linear relationship between the ratio of peak area and the concentration of triacetin within the range from 33.3% to 110% was obtained with r2 0.999.The average recoveries were between 95.4%-105%,with RSD less than 1%.Compared with the method recommended by YC/T 144,this method was more suitable for checking the quality of product.