石山巴豆与毛果巴豆叶中挥发油成分分析

采用水蒸气蒸馏法提取石山巴豆和毛果巴豆叶中的挥发油,利用GC-MS联用仪对其化学成分进行分析和鉴定,以归一化法计算各个化学成分的相对含量。结果表明:从石山巴豆叶鉴定出39种化合物,占总量的95.96%,主要成分是α-松油醇(17.57%)、桉树醇(11.13%)、乙酸松油酯(9.07%)、倍半水芹烯(8.52%)等;从毛果巴豆叶鉴定出55种化合物,占总量的97.8%,以反式-橙花叔醇(9.48%)、α-松油醇(7.51%)、桉树醇(6.43%)、乙酸松油酯(6.72%)为主要成分。两种植物叶中的挥发油成分均以萜醇、倍半萜烯为主,并且其中多种成分具有生物活性,因此研究结果可为石山巴豆和毛果巴豆的开发利用提供科学依据。     

固定化脂肪酶的创制及其在乙酸肉桂酯无溶剂制备中的应用

采用模板法结合辛基(C8)表面修饰制备疏水有序介孔SiO₂载体(OMS-C₈),在此基础上制得固定化脂肪酶(CSL@OMS-C8),成功应用于乙酸肉桂酯的无溶剂酶法制备。利用扫描电镜(SEM)、透射电镜(TEM)、N2-吸附脱附、傅里叶红外(FTIR)对载体材料和固定化酶进行表征。结果显示,OMS具有整齐有序的介孔结构,比表面积达149.9 m2/g,平均孔径为15 nm。经过疏水改性后,接触角从20°提高到120°。优化获得了乙酸肉桂酯的最佳反应条件为温度50℃,肉桂醇与乙酸乙烯酯的摩尔比1∶5,固定化酶添加量2 g/L,反应时间2 h,转化率达到96.6%。催化剂经过5次重复使用肉桂醇的转化率仍能达到80%。     

有机相脂肪酶催化合成乙酸肉桂酯

对有机相中酶法催化合成乙酸肉桂酯的转酯化反应进行研究。结果发现:Candida anatarctic脂肪酶(Novozyme435)、根霉脂肪酶(Rhizopus niveus lipase)和荧光假单胞菌脂肪酶(Pseudomonas fluore lipase)均有较好的催化活性。同时考察各反应参数(温度、反应溶剂、体系水活度、酰化剂类型、肉桂醇与酰化剂摩尔比、肉桂醇浓度等)对脂肪酶Novozyme435合成乙酸肉桂酯反应的影响,确定了反应体系最优工艺条件:在10 mL甲基叔丁基醚中,肉桂醇200 mmol/L,n(肉桂醇)∶n(乙酸乙烯酯)=1∶1.5,初始水活度αw=0.84,温度35℃,酶加量0.02 g,反应3 h后肉桂醇转化率可达到99%,产物经质谱(MS)鉴定。固定化酶经过10个批次反应,反应转化率都保持在90%以上。     

小花八角果实化学成分的研究

利用化学及层析方法从小花八角果实中分离纯化得三个结晶化合物,用UV、IR、NMR、MS等波谱方法分别鉴定为胡萝卜甙(daucosterol)、莽草酸(shikimic acid)和β-谷甾醇(β-sitosterol);同时通过GC/MS/DS方法鉴定了小花八角果实精油中的31种成分,其中主要有1,8-按油脑(21.47％),α-萜品醇(10.40％),樟脑(8.09％),乙酸冰片酯(5.38％),4-萜品醇(5.25％),甲基丁香酚(4.28％)。     

毛桂和少花桂叶精油的化学成分

湖北省鄂西自治州产毛桂和少花桂叶精油,分别使用Finnigan-4510型毛细管气相色谱/质谱/电子计算机联用(GC/MS/DS)方法进行了化学成分分析。从毛桂叶精油中共检出61个成分,鉴定了其中21个化合物,占精油总量的76.39%,主要成分为1,8-桉叶油素(37.02%)和乙酸龙脑酯(16.24%)。从少花桂叶精油中共检出60余个成分,鉴定了其中33个成分,占全精油的77.85%,含量较高的有α-蒎烯(9.09%)、1,8-桉叶油素(8.27%)、香叶醇(6.03%),香叶醛(5.90%),乙酸香叶酯(4.94%)和黄樟油素(4.43%)等。     

依兰花精油的香气成分

云南省西双版纳产依兰油,用Finnigan-4510型毛细管气相色谱/质谱/计算机联用方法进行了化学成分分析,共分离检出了50个成分,鉴定了其中22个成分,占全精油的95.27％。主要成分为:β-丁香烯(33.00％),γ-穆罗烯(19.82％)。α-(艹律)草烯(7.69％),乙酸香叶酯(6.21％),香柠檬烯(5.40％),苯甲酸苄酯(5.33％),金合欢醇(4.75％),金合欢烯(3.29％),香叶醇(2.48％),对甲酚甲醚(2.41％)。并讨论了如何提高国产依兰油质量的问题。     

我国特有植物一木里香橼叶精油化学成分的研究

用气相色谱保留指数定性法、色谱-质谱-计算机联用测定和标准品迭加法分析了木里香橼叶精油的化学成分。从分离出的59个色谱峰中鉴定了31个化合物。其中主要成分是柠檬烯(31.730％)、芳樟醇(1.554％)、香茅醛(23.383％)、香茅醇(1.189％)、橙花醇(11.777％)、香叶醛(16.544％),乙酸香茅酯(1.427％)、乙酸橙花酯(2.258％)、乙酸香叶酯(4.714％)等。把木里香橼叶油与木里香橼果皮油与云南野香橼叶油分别作了比较。结果表明木里香橼叶油中含氧化合物醇、醛、酯的含量相当高,是精油的主要成分,可能作为进口橙叶油的较好的代用品,是一种很有潜力的天然香料资源。     

静置的固定化荧光假单胞菌脂肪酶(PFL)生物反应器中催化合成乙酸香茅酯

为提高脂肪酶催化合成乙酸香茅酯的效率,优化催化条件,通过物理吸附,将脂肪酶Pseudomonas fluorescens lipase(PFL)固定在脱脂棉上,与柱形瓶或滴定管形成简易的生物反应器,并用于催化香茅醇与乙酸乙烯酯反应,合成乙酸香茅酯。结果发现,即使在静置条件下,在脱脂棉固定化PFL瓶型生物反应器中,在37℃催化反应24 h,香茅醇转化成乙酸香茅酯的转化率达96%以上。同样在静置条件下,在脱脂棉固定化PFL管式生物反应器中,在室温下催化反应4 h,香茅醇转化成乙酸香茅酯的转化率达68.5%。显然,制备的固定化酶反应器具有高效的催化作用。     

不同危害状态下寄主山核桃挥发物成分的比较及桑天牛对其组分的GC-EAD和行为反应

【目的】挖掘能影响桑天牛Apriona germari行为反应的山核桃Juglans mandshurica挥发物,为筛选桑天牛的植物源引诱剂或驱避剂提供理论依据。【方法】采用动态顶空套袋法收集不同危害状态[健康(CK)以及桑天牛取食、产卵和钻蛀危害]下山核桃释放的挥发物,并利用气相色谱-质谱联用仪(GC-MS)、气相色谱-触角电位测量系统(GC-EAD)及Y型嗅觉仪分析鉴定出桑天牛成虫对其产生电生理及行为反应的挥发物。【结果】不同危害状态下山核桃释放的挥发物皆以萜烯类和芳香族化合物居多,且有多种成分相对含量存在显著性差异,其中每种危害状态下山核桃释放的挥发物都有一种或几种特有的成分。桑天牛成虫仅对不同危害状态下山核桃释放的蒎烯、乙酸叶醇酯、壬醛、α-萜品醇、丙烯酸-2-乙基己酯及正十六烷6种挥发物产生显著的电生理反应,对其他挥发物无反应,其中雌成虫对壬醛的电生理反应最强,而雄成虫对乙酸叶醇酯的电生理反应最强。嗅觉反应结果显示,丙烯酸-2-乙基己酯仅对桑天牛雌成虫有显著的引诱作用(P0.05),而乙酸叶醇酯则仅对雄成虫有极显著的引诱作用(P0.01);壬醛对桑天牛雌雄成虫均有显著的引诱作用(P0.05),而α-萜品醇则对其有显著的驱避作用(P0.05)。【结论】本研究结果表明,乙酸叶醇酯、壬醛和丙烯酸-2-乙基己酯对桑天牛成虫有较强的引诱作用,而α-萜品醇则对其有较好的驱避作用。     

贵州宽叶缬草油的化学成分

贵州产宽叶缬草(Valeriana officinalis L.var.latifolia Miq.)油,用Finnigan4510型毛细管气相色谱/质谱/计算机联用方法进行了化学成分分析,共检出了29个成分鉴定了其中21个成分,占全精油的92.33%,主要成分为乙酸龙脑酯,α-蒎烯,莰烯,β-蒎烯,柠檬烯,乙酸葛缕酯,二氢乙酸葛缕酯等。该油芬芳,适于调配烟用香精,亦用于调节器配食用香精和化妆品香精。     

Chemotaxonomic study on Thymus villosus from Portugal

The composition of the essential oils of four populations of Thymus villosus subsp. lusitanicus (Boiss.) Coutinho from Portugal was investigated by GC and GC-MS. To study the chemical polymorphism the results obtained from GC analyses of the volatile oils from individual plants from four populations were submited to Principal Component and Cluster analyses. A comparision with the essential oil of T. villosus subsp. villosus, previously studied by us was done. Important differences with regard to the major constituents in these two taxa were found. Linalool, geranyl acetate, geraniol and terpinen-4-ol were the main components of the essential oils of T. villosus subsp. lusitanicus, whereas in the oil of T. villosus subsp. villosus p-cymene, myrcene and alpha-terpineol were the major ones. Although, both taxa showed chemical polymorphism, different types of essential oils were characterized in each one: linalool; linalool/ terpinen-4-ol/trans-sabinene hydrate; linalool/1,8-cineole; geranyl acetate/geraniol; geranyl acetate/geraniol/1,8-cineole in T. villosus subsp. lusitanicus and p-cymene/camphor/linalool; p-cymene/borneol; linalool/geraniol/geranyl acetate; alpha-terpineol/camphor/myrcene in T. villosus subsp. villosus. Thus, the two subspecies of T. villosus can be easely differenciated by the composition of their essential oils.     

超临界CO2萃取茉莉净油化学成分的研究

利用 GC和 GC- MS联用仪对超临界 CO2 萃取茉莉浸膏的净油进行化学成分分析 ,分离出 131个组分 ,鉴定出其中的 35个化合物 ,所鉴定的成分占分离成分的 85%以上。同时将分析结果与普通溶剂法制取的茉莉净油进行比较。     

Composition and infraspecific variability of essential oil from Thymus herba barona Lois

The composition of the essential oils of individual plants of Thymus herba barona Lois. growing wild in Corsica was investigated by GC, GC/MS an carbon-13 NMR. Eight groups of essential oil were distinguished: (i) thymol, (ii) carvacrol, (iii) linalool, (iv) geraniol, (v) -terpenyl acetate, (vi) terpinen-4-ol, (vii) carvone and cis-dihydrocarvone. Three chemotypes -thymol, carvacrol and linalool – are common in the genus Thymus, two others – geraniol, -terpenyl acetate – are scarce, while the latest three ones – terpinen-4-ol, carvone and cis-dihydrocarvone are quite original. It is the first time that the cis-dihydrocarvone chemotype is described in the genus Thymus     

Chemical variability of peel and leaf essential oils of 15 species of mandarins

Peel and leaf oils of 58 mandarin cultivars, belonging to 15 different species were obtained from fruits and leaves collected on mandarin-trees submitted to the same pedoclimatic and cultural conditions. Their chemical composition was investigated by capillary GC, GC/MS and 13C NMR and the results were submitted to a cluster analysis and a discriminant analysis. Three major chemotypes, limonene, limonene/gamma-terpinene and linalyl acetate/limonene, were distinguished for peel oils while three other chemotypes, sabinene/linalool, gamma-terpinene/linalool and methyl N-methylanthranilate, were observed for leaf oils.     

Behavioral responses for evaluating the attractiveness of specific tea shoot volatiles to the tea green leafhopper,Empoaca vitis

Abstract The tea green leafhopper, Empoasca vitis Göthe, is one of the most serious insect pests of tea plantations in mainland China. Over the past decades, this pest has been controlled mainly by spraying pesticides. Insecticide applications not only have become less effective in controlling damage, but even more seriously, have caused high levels of toxic residues in teas, which ultimately threatens human health. Therefore, we should seek a safer biological control approach. In the present study, key components of tea shoot volatiles were identified and behaviorally tested as potential leafhopper attractants. The following 13 volatile compounds were identified from aeration samples of tea shoots using gas chromatography‐mass spectrometry (GC‐MS): (E)‐2‐hexenal, (Z)‐3‐hexen‐1‐ol, (Z)‐3‐hexenyl acetate, 2‐ethyl‐1‐hexanol, (E)‐ocimene, linalool, nonanol, (Z)‐butanoic acid, 3‐hexenyl ester, decanal, tetradecane, β‐caryophyllene, geraniol and hexadecane. In Y‐tube olfactometer tests, the following individual compounds were identified: (E)‐2‐hexenal, (E)‐ocimene, (Z)‐3‐hexenyl acetate and linalool, as well as two synthetic mixtures (called blend 1 and blend 2) elicited significant taxis, with blend 2 being the most attractive. Blend 1 included linalool, (Z)‐3‐hexen‐1‐ol and (E)‐2‐hexenal at a 1 : 1 : 1 ratio, whereas blend 2 was a mixture of eight compounds at the same loading ratio: (E)‐2‐hexenal, (Z)‐3‐hexen‐1‐ol, (Z)‐3‐hexenyl acetate, 2‐penten‐1‐ol, (E)‐2‐pentenal, pentanol, hexanol and 1‐penten‐3‐ol. In tea fields, the bud‐green sticky board traps baited with blend 2, (E)‐2‐hexenal or hexane captured adults and nymphs of the leafhoppers, with blend 2 being the most attractive, followed by (E)‐2‐hexenal and hexane. Placing sticky traps baited with blend 2 or (E)‐2‐hexenal in the tea fields significantly reduced leafhopper populations. Our results indicate that the bud‐green sticky traps baited with tea shoot volatiles can provide a new tool for monitoring and managing the tea leafhopper.     

Investigations of animal blood samples after fragrance drug inhalation by gas chromatography/mass spectrometry with chemical ionization and selected ion monitoring.

The fragrance compounds linalool (1) and linalyl acetate (2) could be detected, identified and quantified (1: 7-9 ng ml-1; and 2: 1-2 ng ml-1 and 4-5 ng ml-1 as free linalool) in blood samples after inhalation in animal experiments (mice) by gas chromatography/mass spectrometry (GC/MS) with chemical ionization (CI) (ammonia); selected ion monitoring (SIM) mode (1: m/z 81, 137 and 154; 2: 47, 57 and 137) and GC/flame ionization detection (FID). The inhalation of these monoterpenes in concentrations of 5 mg l-1 air leads to a significant reduction of the motility of the test animals down to 30-40% with respect to the control group.     

Myrtus communis berry color morphs: a comparative analysis of essential oils, fatty acids, phenolic compounds, and antioxidant activities

Extracts of mature dark blue and white berries from two Tunisian Myrtus communis morphs growing at the same site were assessed for their essential‐oil and fatty‐acid compositions, phenolic contents, and antioxidant activities. The GC and GC/MS analyses of the essential oils allowed the identification of 33 constituents. The oils from the dark blue fruits showed high percentages of α‐pinene (11.1%), linalool (11.6%), α‐terpineol (15.7%), methyl eugenol (6.2%), and geraniol (3.7%). Myrtenyl acetate (20.3%) was found to be the major compound in the oils from white berries. GC Analysis of the pericarp and seed fatty acids showed that the polyunsaturated fatty acids constituted the major fraction (54.3–78.1%). The highest percentages of linoleic acid (78.0%) and oleic acid (20.0%) were observed in the seeds and the pericarps of the white fruits, respectively. The total phenol, flavonoid, and flavonol contents and the concentration of the eight anthocyanins, identified by HPLC analysis, were significantly higher in the dark blue fruits. All extracts showed a substantial antioxidant activity, assessed by the free radical‐scavenging activity and the ferric reducing power, with the dark blue fruit extracts being more effective.     

Volatile and Non-volatile Forms of Aroma Compounds in Tea Leaves and Their Changes due to Injury

Fresh tea leaves were homogenized in a chloroform-methanol mixture (1:1, v/v), and separated into chloroform-soluble and methanol-water-soluble fractions after addition of water. From the chloroform-soluble fraction, the volatile forms of the aroma compounds were obtained. The non-volatile forms of the aroma compounds were associated with the methanol-water-soluble fraction, and were converted to volatile forms by hydrolysis with dilute acid.

The amount of the aroma compounds in the free form, such as cis-3-pentenol, hexanol, cis-3-hexenol, trans-2-hexenol, linalool, linalool oxide (cis, 5-membered), linalool oxide (trans, 5-membered), linalool oxide (trans, 6-rnembered), linalool oxide (cis, 6-membered), nerol, geraniol, phenylmethanol, and 2-phenylethanol, markedly increased during black tea manufacture. However, those in the bound form, showed a slight decrease during the manufacture. The increases in the former were also brought about by maceration, or treatment of the tea leaves with monoiodoacetate or malonate.     

Cytotoxicity of lavender oil and its major components to human skin cells

Abstract.  Lavender ( Lavandula angustifolia ) oil, chiefly composed of linalyl acetate (51%) and linalool (35%), is considered to be one of the mildest of known plant essential oils and has a history in wound healing. Concerns are building about the potential for irritant or allergenic skin reactions with the use of lavender oil. This study has demonstrated that lavender oil is cytotoxic to human skin cells in vitro (endothelial cells and fibroblasts) at a concentration of 0.25% (v/v) in all cell types tested (HMEC-1, HNDF and 153BR). The major components of the oil, linalyl acetate and linalool, were also assayed under similar conditions for their cytotoxicity. The activity of linalool reflected that of the whole oil, indicating that linalool may be the active component of lavender oil. Linalyl acetate cytotoxicity was higher than that of the oil itself, suggesting suppression of its activity by an unknown factor in the oil. Membrane damage is proposed as the possible mechanism of action.