N-丁基-2-甲基-3-乙酰基-5-(1?,2?,3?,4?-四羟基丁基)吡咯的热裂解气相色谱-质谱分析

以D-(+)-氨基葡萄糖盐酸盐为原料,通过环化和烷基化反应合成了目标化合物N-丁基-2-甲基-3-乙酰基-5-(1',2',3',4'-四羟基丁基)吡咯,并通过~1HNMR、~(13)CNMR、IR和HRMS技术对其结构进行表征。采用热重-微分热重-差示扫描量热法(TG-DTG-DSC)分析了目标化合物的热变化情况,结合热裂解-气相色谱-质谱技术(Py-GC-MS)研究了目标化合物在300、600、900℃的热裂解行为,并对目标化合物进行卷烟加香评吸。结果表明:目标化合物的初始裂解温度为137.6℃,二次裂解温度为224.9℃,900℃时裂解物失重约65%;裂解产物总共有43种,其中有2,3-二甲基吡咯、N-甲基-3-乙酰基吡咯、2,4-二甲基-3-乙酰基吡咯等多种具有香味特征的物质;随着温度的升高,总裂解产物的量有增加趋势;目标化合物能够有效改善卷烟品质,增加卷烟香气,并以添加相对烟丝质量的0.03%时,其加香效果最为适宜。初步探讨了目标化合物可能的裂解机理,为研究其在卷烟燃烧过程中的转化行为提供参考。     

麦芽酚-β-D-葡萄糖苷的便捷合成及其加香应用

为了改进糖苷化反应的合成工艺,以D-葡萄糖为原料,合成了溴代四乙酰葡萄糖(Ⅱ),化合物Ⅱ与麦芽酚(Ⅰ)分别经相转移催化和Koenigs-Knorr糖苷化反应合成了麦芽酚-2,3,4,6-四-O-乙酰基-β-D-葡萄糖苷(Ⅲ),化合物Ⅲ脱乙酰基得到目标产物麦芽酚-β-D-葡萄糖苷(Ⅳ)。产物结构经1HNMR、13CNMR、IR、HRMS确证。考察了糖苷Ⅳ的热裂解和加香评吸效果。结果表明,对于糖苷化反应,相转移催化法优于Koenigs-Knorr法。相转移催化法的反应条件为:丙酮为溶剂,无水K_2CO_3为缚酸剂,四丁基溴化铵(TBAB)为相转移催化剂,n(麦芽酚)∶n(溴代四乙酰葡萄糖)=1.0∶1.2,室温反应4h,化合物Ⅲ的产率为75.6%。化合物Ⅲ在甲醇钠/甲醇体系进行水解得到化合物Ⅳ。糖苷Ⅳ受热裂解能释放出麦芽酚等特征香味成分,将其添加于卷烟中能够改善香气品质。     

N-(3-甲酰吡啶)-脯氨酸甲酯的合成及其卷烟加香应用研究

以3-吡啶甲酸为起始原料,经酰氯化反应制成3-吡啶甲酰氯。另以脯氨酸为原料,经酰氯化后再与甲醇反应生成相应的氨基酸甲酯盐酸盐。在室温下,以三乙胺为缚酸剂,3-吡啶甲酰氯与氨基酸甲酯经过酰化反应生成目标产物N-(3-甲酰吡啶)-脯氨酸甲酯化合物。并将其应用于卷烟加香中,以改善卷烟制品品质。化合物结构通过1HNMR、13CNMR、IR和HRMS技术进行了表征。并对产物进行热重分析以及热裂解行为研究,分析鉴定出了40多种裂解产物,其多数为致香物质。对目标物进行卷烟加香评吸,结果表明,该物质能改善卷烟吸味,减轻卷烟吸食刺激性,增强香气。     

医药、兽药

化学法合成L-苯丙氨酸与D-苯丙氨酸 新工艺研究成功 广东工业大学轻工化工学院利用易得的化工原料经两步反应合成制得DL-苯丙氨酸,再利用易得的手性拆分剂对其进行拆分,制得L-苯丙氨酸与平衡制得D-苯丙氨酸(每生产1kg L-苯丙氨酸可同时生产1.1kg D-苯丙氨酸)。前者是重要的食品添加剂——甜味剂阿司巴甜的主原料,也是医药大输液与氨基酸胶囊以及氨基酸口服液的原料药;后者是多种抗癌药的中间体,也是合成多肽等生化制品的原料与试剂,前景良好。     

麦芽酚-β-D-葡萄糖苷的便捷合成及加香应用

为了改进糖苷化反应的合成工艺，以D-葡萄糖为原料，合成了糖基供体溴代四乙酰葡萄糖(Ⅱ)，再与麦芽酚(I)进行糖苷化反应，分别采用相转移催化法和Koenigs-Knorr法，合成了麦芽酚-2, 3, 4, 6-四-O-乙酰基-β-D-葡萄糖苷(Ⅲ)；最后，将化合物Ⅲ进行水解，得到目标产物麦芽酚-β-D-葡萄糖苷(Ⅳ)。所得产物结构经1HNMR、13CNMR、IR、HRMS 确证，并研究了目标糖苷Ⅳ的热裂解和加香评吸效果。结果表明: 两种糖苷化方法所得到的产物均为化合物Ⅲ，相转移催化法更优。相转移催化法的反应条件为：以丙酮为溶剂，无水K2CO3为缚酸剂，四丁基溴化铵（TBAB）为相转移催化剂，n（麦芽酚）∶n（溴代四乙酰葡萄糖）=1: 1.2，室温反应4 h，化合物Ⅲ的产率为 75.6%。用甲醇钠/甲醇体系将化合物Ⅲ水解得到化合物Ⅳ。目标糖苷Ⅳ受热裂解能够释放出麦芽酚等特征香味成分，将其添加于卷烟中能够改善香气品质。     

双酶偶联生物合成L-酪氨酸

多酶偶联催化是酶法制备手性药物中间体的重要方法之一。该文采用双酶偶联体系,利用天冬氨酸转氨酶全细胞催化L-天冬氨酸转氨至苯丙酮酸,生成L-苯丙氨酸,同时得到中间产物丙酮酸;反应体系中的酪氨酸酚裂解酶全细胞催化丙酮酸、苯酚和氨酶法合成L-酪氨酸。经考察确定了双酶偶联反应的最佳条件为:温度40℃,pH=8.5,底物苯丙酮酸质量浓度为25 g/L,苯丙酮酸与L-天冬氨酸摩尔比1∶1.2,天冬氨酸转氨酶与酪氨酸酚裂解酶细胞质量比1∶1,4 mmol/L PLP,0.1 g/L吐温80。30 g/L的氯化铵对双酶偶联反应有促进作用。双菌双酶偶联生物法合成L-酪氨酸,充分利用了反应副产物丙酮酸得到附加值较高的产品,对资源合理利用及绿色合成工艺具有参考意义。     

烟草中番茄红素热裂解产物对卷烟品质的影响

为了研究烟草中番茄红素热裂解产物对卷烟品质的影响,利用热裂解-气相色谱/质谱法模拟番茄红素在卷烟燃吸过程中产物的变化,研究在不同裂解氛围(空气氛围,N_2氛围)和不同裂解温度(300,600,900℃)下番茄红素的裂解产物及其对卷烟品质的影响,并对其机理进行了初步的探讨。结果表明,番茄红素在不同裂解条件下主要的裂解产物是甲苯、对-二甲苯、2,7-二甲基萘、1,3-二甲基萘、1,4,6-三甲基萘和2,3-二氢-1,1,3-三甲基-1H-茚等化合物,另外还生成6-甲基-5-庚烯-2-酮、苯甲醛、甲基苯甲醛、香叶醛、香叶基丙酮和假紫罗兰酮等香味化合物,这些物质随裂解温度和裂解氛围的不同其含量有所差异。     

烟草植醇热裂解产物研究

为了研究植醇热裂解产物对卷烟品质的影响,利用热裂解-气相色谱/质谱法模拟植醇在卷烟燃吸过程中产物的变化情况;研究了在不同气体氛围(N2氛围,含10%O2的N2氛围)和不同裂解温度(300℃,600℃,900℃)条件下,植醇的裂解产物和对卷烟品质的影响,并对机理进行了初步的探讨。结果表明,植醇的主要裂解产物是新植二烯等烯烃类化合物,同时还生成了醇类、醛类、酮类、芳香烃等化合物,这些物质随裂解温度和气体氛围的不同其含量有所差异。     

巨大芽孢杆菌酶法转化制备D-苯丙氨酸

以DL-苯丙氨酸为底物,利用巨大芽孢杆菌(Bacillus megaterium)AS1.127苯丙氨酸脱氨酶光学异构选择性,仅对L-苯丙氨酸专一氧化脱氨,而不作用于D型,从而高效制备D-苯丙氨酸。考察了影响酶促反应的几种因素,得到了最佳酶促反应条件,结果表明,该转化反应最适温度37~40℃。最适pH 5.8,0.2%磷酸缓冲液可提高脱氨酶活力,在反应液中加入表面活性剂0.2%吐温-80或10-5mol/L K 能显著提高脱氨酶活力。转化率与底物浓度、菌体用量有关,在此反应体系中,底物DL-苯丙氨酸浓度0.09 mol/L,菌体用量0.03 g/mL,转化时间18 h,L-苯丙氨酸转化率最高达98%以上。转化液经脱色、减压浓缩和等电点结晶后得D-苯丙氨酸,比旋光为[a]2D0= 32.4°,光学纯度达到95%以上。     

葡萄糖与组氨酸热解产物分析及其在卷烟纸中的应用

模拟卷烟纸及卷烟纸助剂燃烧、热裂解环境和条件,采用PY-GC-MS联机分析方法和卷烟感官评吸方法,进行L-组氨酸、葡萄糖及L-组氨酸和葡萄糖混料的热解产物对比分析及应用评价,结果表明:①在200,500,700℃热解温度条件下,L-组氨酸和葡萄糖混料能够产生大量杂环类致香物质,热解反应产物种类数量明显多于L-组氨酸和葡萄糖热解产物种类之和;②L-组氨酸和葡萄糖混料热解反应温度低于L-组氨酸和葡萄糖,且在200℃时就能够发生较为复杂的热解反应;③L-组氨酸和葡萄糖混料能够有效地提高卷烟纸的抽吸品质,增加卷烟香气的丰富性。     

Die antioxidative Wirkung von Produkten der Maillard-Reaktion in Modellsystemen und gerösteten Haselnüssen

The Antioxidative Effect of Maillard Reaction Products in Model Systems and Roasted Hazelnuts Solutions of glucose and various amino acids were heated in phosphate buffer pH 7.0. Browning and reducing power of these Maillard reaction solutions showed correlation and increase in the ordeaicid -neutral — basic amino acids. Upon addition to emulsions of methyl imoleate (ML) in water the antioxidative effect increased in the order basic — acid — neutral amino acids. The respective amino acids alone had no effect, various Amadori compounds (fructose-alanine. -arginine and -histidine) a prooxidative effect. Extracts from roasted, defatted hazelnuts also showed correlation between browning and reducing power. Water extracts possessed higher browning and reducing power than the corresponding methanol extracts; the antioxidative effect of both extracts in ML emulsions however was comparable and increased with the roasting time as well as with the amount of extract added. The extracts were separated by gel permeation chromatography on Sephadex G-15 into three main fractions. An antioxidative effect was mainly found in the fraction of low molecular colourless Maillard reaction products.     

Zum Einfluß von Antioxidantien natürlichen Ursprungs auf die Stabilität von Linolsäuremethylester in Modellsystemen

The Effect of Natural Antioxidants on the Stability of Methyl Linoleate in Model Systems This paper presents a model system based on linoleic acid methylester on potato starch which allows to estimate the antioxidative effects of certain additives in oxygen-sensitive foods of low lipid content. It is shown that a tocopherol mixture from natural sources (Covi-Ox T70) and an extract from rosemary (RM) were much more effective than the conventional ascorbyl palmitate (AP). So concentrations of 2 ppm Covi-Ox T70 or 20 ppm RM, respectively, were more effective than 200 ppm AP. Reducing intermediates of the Maillard reaction (Amadori compounds) do not show antioxidative effects in all cases; in our investigations only fructose-γ-aminobutyric acid and fructosearginine were able to retard linoleic acid oxidation to some extent; however, in the latter case, the free amino acid showed a similar effect. The antioxidative effect of the different additives tested is due to their radical scavenging character; only AP was able to reduce the hydroperoxides arising from autoxidation processes to the corresponding hydroxy compounds which cannot be decomposed to rancid products anymore.     

4种药剂对烟草花叶病控制研究

为寻找能有效防治烟草花叶病的药剂，该试验选用了4种药剂，在烟草上进行田间小区实验，结果表明，2％宁南霉素和99植保对烟草花叶病的控制效果较好，防治效果达83．20％和78．78％，同时对烟株的植物学性状有促进作用。     

Bovine serum albumin-sugar conjugates through the maillard reaction: effects on interfacial behavior and emulsifying ability

Bovine serum albumin (BSA) was employed as a model protein emulsifier to conjugate with aldohexose (D-glucose (Glc) or D-allose (All)) and sugar fatty acid ester (6-O-octanoyl-D-glucose (GlcC8)) through the Maillard reaction. It was found during the reaction that rate of decrease of free amino groups in BSA was almost the same for the BSA-sugar mixtures whereas browning and protein aggregation developed in the following order: Glc < All < GlcC8. It was thought that the rate of degradation of the Amadori compound could have been influenced by the OH-group stereochemistry at the C3 position of aldohexose, while denaturation of BSA by GlcC8 enhanced the browning and protein aggregation. To understand the emulsifying ability of the BSA-sugar conjugates, hexadecane-water interfacial tension and the oil droplet size of emulsions prepared by homogenizing hexadecane and aqueous solution of the conjugates were examined. BSA-GlcC8 showed greater improvement in interfacial and emulsifying activity than did BSA-Glc and -All. However, no improvement in emulsion stability was observed for any of the BSA-sugar conjugates, suggesting the weakness of the film formed at the oil droplet interface.     

天然化合物丁香酚抗烟草花叶病毒病作用机制初探

[目的]初步研究丁香酚对植物病毒病的作用机制.[方法]利用盆栽法测定了丁香酚对烟草花叶病毒病的预防和治疗效果;电镜法观察了丁香酚对病毒粒子的影响;体外混合法测定了丁香酚对烟草花叶病毒外壳蛋白体外聚合的影响.[结果]丁香酚对烟草花叶病毒病具有较好的预防和治疗效果;丁香酚与病毒混合处理后,病毒粒子有断裂现象;丁香酚对TMV外壳蛋白体外聚合有一定的抑制作用.[结论]丁香酚可以作为新型抗病毒剂用于防治作物病毒病.     

微波膨胀烟梗颗粒的顶空-SPME-GC-MS分析

为评价滤嘴中微波膨胀烟梗颗粒对卷烟香气的影响,在40,60,80℃三个顶空温度条件下,采用顶空-SPME-GC-MS分析方法对微波膨胀烟梗颗粒的挥发性致香成分进行分析。结果表明,膨胀烟梗颗粒可以释放致香成分,并且随着温度的升高,所产生的致香物质种类增多,致香成分构成发生较大改变,醛酮类致香成分所占的比重越大,膨胀烟梗颗粒的增香效果更显著。     

Study on the Effect of Cut Tobacco Drying on the Pyrolysis and Combustion Properties

In order to establish the effect of cut tobacco drying on the subsequent pyrolysis and combustion properties, an oven drying method was applied to the treatment of the cut tobacco samples in a temperature range from 70 to 170°C. Thermogravimetric analysis was used to study the weight loss behavior of the dried cut tobacco samples under N₂ and air atmospheres. The routine chemical components in tobacco were also determined with standard methods. The results showed that oven drying prepared uniformly treated samples. Low-temperature drying (at 70 and 110°C) had little effect on the pyrolysis and combustion properties, but high-temperature drying (at 150 and 170°C) led to a considerable reduction of sugar while producing new components that are harder to decompose.     

精噁唑禾草灵6.9%水乳剂防治烟地杂草药效试验

试验结果表明,精噁唑禾草灵6.9%EW1200,1500mL/hm2对禾本科杂草有明显的除草效果,其除草、保产效果明显优于精噁唑禾草灵6.9%EW600、900mL/hm2,稍高于乙草胺50%EC3000mL/hm2,是一种较理想的烟田除草剂。建议使用剂量为精噁唑禾草灵6.9%EW1200、1500mL/hm2和乙草胺50%EC3000mL/hm2,可推广应用。     

25%噻虫嗪水分散粒剂防治烟蚜田间药效试验

山东青州的田间药效试验结果表明．25％噻虫嗪水分散粒剂在移栽前苗期灌根．大田茎叶期喷雾防治烟蚜都有很好的效果．持效期20d左右。苗期灌根防治烟蚜建议使用浓度4000倍．大田茎叶期喷雾防治烟蚜使用浓度为1000～12000倍，防效均为100％。     

Effect of two-stage dehydration on retention of characteristic flavor components of flue-cured tobacco in rotary dryer

Two-stage dehydration method of flue-cured tobacco in rotary dryer was experimentally evaluated and compared to the single-stage dehydration process. The characteristic flavor components in dried cut tobacco, including major Maillard reaction compounds and carotenoid degradation products, as well as drying rate were analyzed for different two-stage dehydration operations. The results showed that both the pre-drying temperature and intermediate moisture content had a significant effect on the overall drying rate of cut tobacco during two-stage drying. On the other hand, the retention of characteristic flavor components in tobacco, especially Maillard reaction compounds retention, was influenced significantly by the final drying temperature as well as intermediate moisture content. The 10°C increase in the final drying temperature from 100 to 110°C reduced the retentions of Maillard reaction compounds and carotenoid degradation products by 14.5 and 9.4%, respectively. Change of intermediate moisture contents from 19 to 15% reduced the Maillard reaction compounds retention by 14.7%. Given the consideration of characteristic flavor components’ retention and drying process efficiency, two-stage dehydration of cut tobacco in rotary dryer could reach a better performance as compared with the single-stage dehydration. The cylinder-wall temperature combination of 140/100°C with the 17% intermediate moisture content could be used as the optimal two-stage condition for the investigated flue-cured tobacco.