芸苔属蔬菜硫代葡萄糖苷含量

对芸苔属中白菜类、芥菜类和甘蓝类蔬菜的硫代葡萄糖苷 (简称硫苷 )组成与含量进行了评价。结果表明 ,散叶甘蓝硫苷总含量最高 ,其次是包包青菜、包心芥菜、芥蓝 ,小白菜的含量最低。不同的品种硫苷的类型和含量不同。白菜类中 ,小白菜主要的硫苷为 3-丁烯基和 1 -甲氧基 - 3-吲哚基甲基硫苷 ,菜心中为 3-丁烯基和 2 -羟基 - 3-丁烯基硫苷 ,苔菜中为1 -甲氧基 - 3-吲哚基甲基和 4-戊烯基硫苷。在芥菜类中 ,发现了两种不同硫苷类型 ,烯丙基硫苷是包包青菜、包心芥菜主要的硫苷 ,约占总含量的 90 % ;而在小叶芥中 3-丁烯基为主要的硫苷 ,占总含量的大约 70 %。甘蓝类中羽衣甘蓝主要含有3-吲哚基甲基硫苷和 3-甲基硫氧丙基硫苷。 4-甲基硫氧丁基硫苷的含量以芥蓝中最高 ,此外 3-丁烯基硫苷的含量也比较高。在散叶甘蓝中 ,2 -羟基 - 3-丁烯基硫苷是主要的组成 ,约占总含量的 43% ,烯丙基硫苷和 3-吲哚甲基硫苷占总含量的2 0 %左右 ,芥蓝中萝卜硫素前体 4-甲基硫氧丁基硫苷的含量可达 1 2 4 .1 μmol/ 1 0 0 g FW,是很有抗癌价值的十字花科蔬菜。     

甘蓝不同部位及加工对硫代葡萄糖苷组分和含量的影响

采用高效液相色谱法对甘蓝内叶、外叶、漂烫及真空干燥后的硫苷含量进行了成分鉴定及组分分析.结果表明,甘蓝内叶与外叶的组分相同,通过HPLC-ESI-MS共鉴定出5种脂肪族硫苷(3-甲基硫氧丙基GS,2-羟基-3-丁烯基GS,2-丙烯基GS,3-丁烯基GS,4-戊烯基GS)和1种吲哚族硫苷(3-吲哚基甲基GS),甘蓝中主要硫苷成分为2-羟基-3-丁烯基GS,2-丙烯基GS,3-吲哚基甲基GS及3-甲基硫氧丙基GS,内叶和外叶中硫苷含量分别为1 972 μg/g干重和1 941 μg/g干重,漂烫和真空干燥后硫苷的保存率分别为87.7％和37.4％.     

硫甙R基的多变性

<正>1．硫甙的基本结构硫代葡萄糖甙(gleucsinolates)简称硫甙、GS。广泛分布于双子叶植物十字花科中,特别是芸苔属的各种植物,如油菜、白菜、萝卜等,榨油后残留在油渣中。据文献报道,硫代葡萄糖甙种类较多,在1948年以前鉴定为3种,1982年曾对菜籽饼的硫代葡萄糖甙进行系统调查,鉴定为七种。这七种是:3-丁烯基硫甙,4-戊烯基硫甙;4-甲基硫氨基硫甙;5-甲基硫氧基硫甙,2-苯基乙基硫甙;2-羟基-3-丁基硫甙;2-羟基-4-戊烯基硫甙。硫甙是一类有毒物质,含有硫甙的饼粕饲     

2,5-二甲基-3-乙酰硫基四氢呋喃立体异构体制备及香气特征

研究2,5-二甲基-3-乙酰硫基四氢呋喃立体异构体的制备方法。以丙醛与丙二酸为起始原料,通过Knoevenagel缩合反应得到(E)-3-戊烯酸,然后与甲基锂试剂亲核加成,经过硼氢化钠还原、甲磺酰化、双键环氧化后关环,得到中间体2,5-二甲基-3-羟基四氢呋喃。将该中间体进行衍生,把羟基转化为p-硝基苯甲酸酯,通过柱层析将立体异构体混合物分离,酯基经过水解后分别得到r-2,c-5-二甲基-t-3-羟基四氢呋喃和r-2,t-5-二甲基-t-3-羟基四氢呋喃。最后将羟基转化为甲磺酸酯,与硫代醋酸反应,分别得到r-2,c-5-二甲基-c-3-乙酰硫基四氢呋喃和r-2,t-5-二甲基-c-3-乙酰硫基四氢呋喃。立体异构体产物通过GC-O进行了评香分析,其香气特征和强度均存在明显差别。     

卷烟主流烟气中杂环烃类化合物的分析

以D7-喹啉为内标,采用碱性Al2O3固相萃取和GC/MS/SIM法同时测定了6种卷烟样品主流烟气粒相物中的苯并[b]呋喃、喹啉、咔唑、9-甲基咔唑、二苯并[a,j]吖啶、二苯并[a,h]吖啶和7H-二苯并[e,g]咔唑.结果表明:①方法的检测限在0.04～0.43 ng/支之间,回收率76.0%～119.2%,除9-甲基咔唑的RSD为8.21%外,其它成分的RSD均小于3%;②苯并呋喃、喹啉、咔唑和9-甲基咔唑等杂环烃类化合物的含量与文献报道基本一致;③未检出二苯并[a,j]吖啶、二苯并[a,h]吖啶和7H-二苯并[e,g]咔唑;④除9-甲基咔唑外,3种国产烤烟型卷烟样品烟气中的苯并[b]呋喃、喹啉和咔唑含量均明显高于2种参比卷烟和1种进口混合型卷烟.     

咸味 香精发展趋势

我国咸味香精经历近30年的发展,在十年前2-甲基-3呋喃硫醇、3-巯基-2-丁醇、甲基(2-甲基-3-呋喃基)二硫醚、双(2-甲基-3-呋喃基)二硫醚、呋喃酮、四氢噻吩-3-酮、2,3-丁二硫醇、2-甲基四氢呋喃-3-硫醇、2,5-二甲基-2,5-二羟基-1,4-二噻烷、α-甲基-β-羟基-á-甲基-β-巯基丙硫醇、4-羟基-2,5-二甲基-3(2H)-呋喃酮、2-甲基-3-甲硫基     

佩兰挥发油化学成分的分析

本实验采用同时蒸馏萃取法(SDE)提取佩兰挥发性成分,测得佩兰挥发油的含量为2.73%,利用气相色谱.质谱(GC-MS)联用方法从佩兰挥发油中分离并确认出33种化学成分,用峰面积归一化法通过G1710BA化学站数据处理系统得出各化学成分在挥发油中的百分含量,其中主要成分为2H-1-苯并吡喃-2-酮(12.58%)、麝香草酚(4.38%)、2,4,5,6,7,8-羟基-1,4,9,9.四甲基-3H-3a,7桥亚甲基甘菊环(4.50%)、氧化石竹烯(5.27%)、1-甲基-4-(1-丙基)-酚(3.97%)、1,1a,4,5,6,7,7b,8-八氢-1,1,7,7a四甲基-2H-环丙基[a]萘-2-酮(3.62%).     

复合苦味抑制剂对安塞蜜苦味抑制效果研究

探讨了在不影响安塞蜜溶液其他风味的前提下,阿魏酸、4-(2,2,3-三甲基环戊-3-烯基)丁-2-烯酸、乳酸锌对安塞蜜的苦味抑制效果.并在单因素实验的基础上,采用正交实验设计选出了最佳复配方案.同时,研究了此复合苦味抑制剂对咖啡苦味的抑制效果.结果表明:阿魏酸浓度为110 mg/L,4-(2,2,3-三甲基环戊-3-烯基)丁-2-烯酸浓度为140 mg/L,乳酸锌浓度为80 mg/L时,安塞蜜溶液苦味可从很苦降低到苦,而且此复合苦味抑制剂对咖啡具有有效的苦味抑制作用.     

滤嘴通风对卷烟主流烟气主要氮杂环类碱性香味成分释放量的影响

为明确滤嘴通风对卷烟主流烟气主要含氮杂环类碱性香味成分释放量的影响规律及合理调节烟气平衡,采用GC-MS法分析了不同滤嘴通风度卷烟烟气氮杂环类碱性香味成分(简称碱性香味成分)的释放量。结果表明:①卷烟烟气碱性香味成分主要为吡啶类和吲哚类,两者约占烟气总释放量的90%,其中吡啶类主要为2,3'-联吡啶、吡啶、3-乙烯基吡啶和3-甲基吡啶,吲哚类主要为2-甲基吲哚;②随卷烟滤嘴通风度的增加,烟气中16种主要碱性香味成分释放量及碱性香味成分释放总量呈逐渐降低的趋势,但降低程度差异较大;③随卷烟滤嘴通风度的增加,16种主要碱性香味成分的释放量对烟气碱性香味成分释放总量的贡献差异较大,2,3'-联吡啶、3-甲基吡啶、4-甲基吡啶、2-乙基吡啶和2,6-二甲基吡嗪等成分占烟气碱性香味成分释放总量的比例呈升高趋势(正贡献),吡啶、3-乙烯基吡啶、2-甲基吡啶、喹啉和异喹啉等成分是负贡献,2-乙酰基吡咯、2-甲基吲哚和2,4-二甲基吡啶等组分几乎无变化。     

四川主产烟区烤烟主流烟气特征成分分析

为分析四川省不同种植区烤烟烟叶燃吸时主流烟气的化学成分,以四川省凉山州、攀枝花市、泸州市、宜宾市和广元市5个产区的35个烤烟样品(C3F)为原料制成单料烟支,采用自制的烟气捕集装置与GC/MS结合法对烟支主流烟气进行了定性和定量分析,并进行主成分(PCA)和正交偏最小二乘判别分析(OPLS-DA)。结果表明:①选取匹配度≥79%时,四川省烤烟单料烟支主流烟气中共检出68种化学成分;②川西南(凉山州和攀枝花市)、川南(泸州市和宜宾市)和川北(广元市)3个种植区主流烟气化学成分释放量的差异明显,而品种间化学成分释放量的差异较小;③川西南种植区特征烟气成分为乙酸松油酯,川南种植区特征烟气成分为2-戊酮、1-氯代十一烷、2-乙酰基呋喃、2-甲基-1-苯基丙烯、5-甲基-3-己烯-2-酮和苯乙烯,川北种植区特征烟气成分为1-甲基环辛烯。     

二氢薄荷内酯的合成及卷烟加香应用

以无水苯和四氢呋喃为溶剂,锌粉催化2-溴丙酸甲酯与4-甲基环己酮Reformatsky反应制得2-(4-甲基-1-羟基环己基)丙酸甲酯,皂化和酸化后,得到2-(4-甲基-1-羟基环己基)丙酸,后用77%浓硫酸处理使之转变为二氢薄荷内酯,总收率为67%。二氢薄荷内酯在烟丝中的优化添加比例为2 mg/kg,它在卷烟中起到增强烟香和甜润感、减少刺激、掩盖杂气的作用。     

Bitterstoffe beim Erhitzen von Saccharose, Maltose und Prolin 2. Mitteilung

Summary In addition to the mono- and dipyrrolidinohexosereductones described recently (Z Lebensm Unters Forsch (1984) 178:356) two further bittertasting compounds were isolated from heated mixtures of proline and sucrose (molar ratio 3: 1, 190 °C, 30 min) and also synthesized, namely 2,3-bis-(1-pyrrolidinyl)2-cyclopenten-l-one and 2,3-bis(1-pyrrolidinyl)-5methyliden-2-cyclopenten-l-one. The recognition thresholds (mmol/1) are 0.15–0.25 and 0.06–0.12 respectively. Both compounds have a burning bitter taste character. From a maltose-proline reaction mixture 2--glucosyl-5-hydroxy-5-methyl-4-piperidinyl-2-cyclopenten-1-one was isolated. When the dihydroxypyranone VI was heated with proline, 2,5-dihydroxy-5-methyl-4-prohnyl-2-cyclopenten-1-one and the cyclopent(b)azepinones XI and XII were among the compounds formed. These compounds also have a bitter taste character.Zusammenfassung Zusätzlich zu den kürzlich beschriebenen Mono- and Dipyrrolidinohexosereduktionen (Z Lebensm Unters Forsch (1984) 178:356) wurden zwei weitere bittere Verbindungen aus erhitzten Mischungen von Prolin and Saccharose (Molverhältnis 3:1, 190 °C, 30 min) isoliert and synthetisiert. Es handelt sich um 2,3-Bis-(1-Pyrrolidinyl)-2-cyclopenten-1-on und 2,3-Bis-(1-Pyrrolidinyl)-5-methyliden-2-cyclopenten-1-on. Die Erkennungsschwellenwerte (mmol/1) sind 0,15-0,25 and 0,06-0,12. Beide Verbindungen haben einen brennend-bitteren Geschmack. Aus einem Maltose-Prolin-Umsetzungsgemisch gelang die Isolierung des 2--Glucosyl-5-hydroxy-5-methyl-4-piperidinyl-2-cyclopenten-1-ons. Bei der Reaktion des Dihydropyranons VI mit Prolin wurden u. a. das 2,5-Dihydroxy-5-methyl-4-prolinyl2-cyclopenten-1-on sowie die Cyclopent(b)azepinone XI and XII gebildet. Diese Verbindungen sind ebenfalls mehr oder weniger stark bitter.     

4-甲基-4-烷硫基-2-戊酮类化合物的合成研究

对4-甲基-4-烷硫基-2-戊酮类化合物的合成与香气特征进行了研究。具体方法是:在四氢呋喃溶剂中,4-甲基-3-戊烯-2-酮与各种硫醇在哌啶的催化作用下回流反应20h,得到5种4-甲基-4-烷硫基-2-戊酮类新型食用香料化合物,产率40.3%～65.1%,其中烷硫基分别为乙硫基、丙硫基、丁硫基、己硫基、糠硫基。4-甲基-3-戊烯-2-酮是通过丙酮醇在碘催化剂作用下加热脱水制取的。采用IR、GC-MS、1HNMR分析并确证了上述合成化合物的结构,并对其香气特征进行了描述,它们可能是潜在的食用香料。     

Investigation of the glucose/propylamine reaction by HPLC

The reaction of glucose with propylamine has been investigated by HPLC. The main products detectable by UV absorption were 4-hydroxy-2-(hydroxymethyl)-5-methyl-3(2H)-furanone (4), 2,3-dihydro-3,5- dihydroxy-6-methyl-4H-pyran-4-one (5), 5-hydroxymethyl- 2-furancarbaldehyde, 3-(1,2,3-trihydroxypropyl)-1-propyl-2-pyrrolecarbaldehyde (6a) and 5-hydroxymethyl- 1-propyl-2-pyrrolecarbaldehyde (7a). The yield of products was highly dependent on the reaction conditions. In neutral solution mainly4 and5 were formed, whereas at pH 5.0 pyrroles dominated.

---

Untersuchung der Reaktion zwischen Glucose und Propylamin mittels HPLC

Zusammenfassung Umsetzungen von Glucose mit Propylamin wurden mit Hilfe der HPLC untersucht. Die durch UV-Absorption detektierbaren Hauptprodukte sind: 4-Hydroxy-2-(hydroxymethyl)-5-methyl-3(2H)-furanon (4), 2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-on (5), 5-Hydroxymethyl-2-furancarbaldehyd, 3- (1,2,3-Trihydroxypropyl)-1-propyl-2-pyrrolcarbaldehyd (6a) und 5-Hydroxymethyl-1-propyl-2-pyrrolcarbaldehyd (7a). Die Ausbeuten hängen sehr von den Reaktionsbedingungen ab. In neutraler Lösung werden überwiegend4 und5 abgebildet, während bei pH 5 Pyrrole dominieren.

     

金属络合衍生-高效液相色谱法测定卷烟主流烟气中的氰化氢

建立了金属络合衍生和反相高效液相色谱检测主流烟气中氰化氢的方法。该方法以Ni(II)-NH₃为金属络合衍生化试剂,以5 mmol/L四戊基溴化铵为离子对试剂,分析时间小于10 min。氰化物标准工作曲线在0.1~20 μg/mL范围内线性关系良好(R²> 0.999);检出限和定量限分别为0.049 和0.162 μg/支;3个加标水平回收率在87.41%~119.47%。该法与连续流动法测定结果较为一致:肯塔基对照卷烟3R4F检测结果相对偏差为-5.35%,15种卷烟样品测定结果相对偏差在-0.79%~8.51%。     

2004年我国卷烟焦油量的探索性数据分析

介绍了探索性数据分析法的主要特点,并运用该方法对2004年我国卷烟的焦油量进行了探索性数据分析。结果表明:2004年全国有75%以上的卷烟焦油量降到了15.0mg/支以下,有25%以上的卷烟焦油量降到了13.0mg/支以下,卷烟焦油量的整体水平约为13.8mg/支;一、二类卷烟的焦油量明显高于三、四类卷烟,说明其降焦难度相对较大;各企业降焦控焦能力有较大的差异,部分企业的降焦控焦能力较强;2004年第3季度卷烟焦油量的典型值较上半年有增加趋势,但仍有部分企业的控焦水平明显高于上半年;探索性数据分析法所得结论的耐抗性和稳健性明显高于简单加权算术平均值和样本标准偏差方法。结论:探索性数据分析法是一种耐抗性和稳健性的分析方法。     

Cajanuslactone,a new coumarin with anti-bacterial activity from pigeon pea [Cajanus cajan (L.) Millsp.] leaves

The bioassay-guided fractionation of the CHCl₃ extract from pigeon pea leaves led to the isolation of a new natural coumarin, named as cajanuslactone (1), together with two known phytoalexins, pinostrobin (2) and cajaninstilbene acid (3). The structure of 1 was elucidated by interpreting spectroscopic data of UV, IR, MS, 1D and 2D NMR. It was determined as 7-hydroxy-5-O-methyl-8-(3-methyl-2-butylene)-4-phenyl-9,10-dihydro-benzopyran-2-one. The anti-bacterial activity against three Gram-positive microorganisms was evaluated in vitro. It was found the new compound cajanuslactone possessed good anti-bacterial activity against Staphylococcus aureus (ATCC 6538), and the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were 0.031 and 0.125 mg/ml, respectively. The result indicated that the leaf part of pigeon pea is an excellent source of natural anti-bacterial materials. Moreover, cajanuslactone is a potential anti-bacterial agent against Gram-positive microorganisms.     

Detection of Maillard products of lactose in heated or processed milk by HPLC/DAD

 Two HPLC methods with diode array detection were used to separate Maillard products from milk components. The Maillard products 4-(β-d-galactopyranosyloxy)-2-hydroxy-2-methyl-2H-pyran-3(6H)-one (2), 1-[3-(β-d-galactopyranosyloxy)-2-furanyl]-1-ethanone (4), 4-(β-d-galactopyranosyloxy)-5-(hydroxymethyl)-2-methyl-3(2H)-furanone (5), isomaltol (7), maltol (9), 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (6), and 5-hydroxymethyl-2-furfuraldehyde (8) were determined using a water-methanol gradient. Furthermore, 4,5-dihydroxy-2-(β-d-galactopyranosyloxy)-5-methyl-2-cyclopenten-1-one (3) was separated from the milk components by applying the interaction reagent octylamine. Several heated or processed milk samples were analyzed, and formation of the Maillard products was determined and quantified. Thus it was found that 2 and 3 are early products of the Maillard reaction in milk, whereas after prolonged heating 4, 5, and particularly 9 and 6 become more important. Compounds 7 and 8 were not detected, even if the samples were heated under stringent conditions.     

Detection of Maillard products of lactose in heated or processed milk by HPLC/DAD

 Two HPLC methods with diode array detection were used to separate Maillard products from milk components. The Maillard products 4-(β-d-galactopyranosyloxy)-2-hydroxy-2-methyl-2H-pyran-3(6H)-one (2), 1-[3-(β-d-galactopyranosyloxy)-2-furanyl]-1-ethanone (4), 4-(β-d-galactopyranosyloxy)-5-(hydroxymethyl)-2-methyl-3(2H)-furanone (5), isomaltol (7), maltol (9), 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (6), and 5-hydroxymethyl-2-furfuraldehyde (8) were determined using a water-methanol gradient. Furthermore, 4,5-dihydroxy-2-(β-d-galactopyranosyloxy)-5-methyl-2-cyclopenten-1-one (3) was separated from the milk components by applying the interaction reagent octylamine. Several heated or processed milk samples were analyzed, and formation of the Maillard products was determined and quantified. Thus it was found that 2 and 3 are early products of the Maillard reaction in milk, whereas after prolonged heating 4, 5, and particularly 9 and 6 become more important. Compounds 7 and 8 were not detected, even if the samples were heated under stringent conditions. Received: 25 June 1998     

Structure determination of new analogues of vardenafil and sildenafil in dietary supplements

New analogues of vardenafil and sildenafil illegally added to dietary supplements were detected by high-performance liquid chromatography (HPLC) analysis with a photodiode array detector (PDA). These compounds were isolated and their structures elucidated by mass spectrometry (MS), infrared (IR) spectroscopy, one- and two-dimensional nuclear magnetic resonance (NMR). One of the new analogues given the trivial name pseudovardenafil (compound 1) was structurally elucidated and shown to be 1-[[3-(1,4-dihydro-5-methyl-4-oxo-7-propylimidazo[5,1-f][1,2,4]triazin-2-yl)-4-ethoxyphenyl]sulfonyl]-piperidine. It was a vardenafil analogue isolated from a dietary supplement capsule. Compared with vardenafil, the piperidine ring was substituted for the ethylpiperazine group. The second new analogue, trivially named hydroxyhongdenafil (compound 2), was separated from bulk powder used as a raw material for a dietary supplement. The piperazine and phenyl groups were connected through an acetyl group instead of a sulfonyl group, and hydroxyethylpiperazine was substituted for the methylpiperazine of sildenafil. It was structurally elucidated as 5-[2-ethoxy-5-[[4-(2-hydroxyethyl)-1-piperazinyl]acetyl]phenyl]-1,4-dihydro-1-methyl-3-propyl-7H-pyrazolo[4,3-d]pyrimidin-7-one.