Functional copolymer of geraniol and acrylonitrile: Synthesis and characterization

The radical copolymerization of acyclic terpene namely geraniol [GER] with acrylonitrile [AN] in DMF at (70 ± 0.1)°C for 1 h, using benzoylperoxide (BPO) as an initiator has been carried out under inert atmosphere of nitrogen. The kinetic expression for reaction is R_p ∝ [BPO]^0.5 [AN]^1.0 [GER]^1.0. The IR spectrum of the copolymer shows bands at 3432 and at 2244 cm^?1 due to ? OH group of GER and ? CN group of AN, respectively. The ¹³C‐NMR spectrum shows peaks at 73–75 δ ppm and 116–120 δ ppm due to ? OH group of GER and ? CN group of AN, respectively. The thermogravimetric analysis and differential scanning calorimetry study shows that copolymer is thermally stable up to 407°C and has glass transition temperatures (T_g) 56°C. The reactivity ratios r₁ (AN) and r₂ (GER) have been calculated as 0.05 and 0.005, respectively. The Alfrey‐Price Q‐e parameter for GER has been calculated as 0.094 and ?2.0, respectively. The molecular weights of the copolymers have been evaluated by gel‐permeation chromatography. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

真空间歇精馏分离橙花醇和香叶醇的研究

橙花醇和香叶醇是重要的基础香料,沸点差仅为2℃,具有热敏性。以往研究中应用减压间歇精馏分离橙花醇和香叶醇的混合物,一次精馏得到90%以上的产品收率低(仅为46%),且塔釜温度较高,操作周期长,不宜于工业生产。本文针对沸点差较小的热敏性物系,采用减压高效间歇精馏方法对橙花醇和香叶醇的混合物进行了分离研究。通过考察全回流时间、回流比、加热负荷和压力等操作因素对分离效果的影响,确定了适宜的操作条件,塔顶压力为600Pa～700Pa,塔压降为4800Pa～4900Pa,釜温在150℃～152℃之间,全回流6h,采用20 1,10 1,5 1的变回流比操作。实验结果显示,单塔精馏即可得到含量大于90%的橙花醇和香叶醇,收率在65%以上,提高20%无热分解现象,过程稳定,为工业生产奠定了基础。     

Shape-selective separation of geraniol and nerol via noncovalent interactionswith β-cyclodextrin

In this paper, selective separation of the isomeric compounds geraniol and nerol, based on the preferential affinity of β-cyclodextrin (β-CD) for geraniol was investigated. To demonstrate the potential application of β-CD for separation of geraiol from nerol, the structure of the inclusion complexes was characterized with various physico-chemical techniques. The selective noncovalent binding property of β-CD was confirmed by quantum-chemical calculations. For the mixture, which contains 50 wt% of geraniol and nerol, respectively, 96% of geraniol in complex can be obtained, and the similar separation efficiency was found after use for three times.     

Exploring the anticancer properties of essential oils from family Lamiaceae

Lamiaceae is among the largest families of flowering plants with about 250 genera and over 7,000 species distributed around the world. It is considered as the important source of essential oils, for example, menthol, geraniol, eucalyptol, camphor and thymol. Therefore, it is imperative to study these economically important compounds under in vitro conditions for their sustainable and enhanced production. In addition to proven biological activities, essential oils from this family have recently been evaluated for anticancer activities and considered as a source of anticancer drugs. Mechanisms involved in the essential oils-mediated antiproliferative activity include cell cycle arrest, apoptosis and DNA repair mechanisms. Essential oils also act in the reduction of tumors, inhibiting metastasis and as anti-multidrug resistance molecules. The aim of this review is to assess the anticancer properties of essential oils obtained from different members of family Lamiaceae. The available reports on active components of essential oils and their effect on cancer type and cell line have been discussed. Biotechnological studies to improve the production of essential oils have also been highlighted. Various methods have been adopted to obtain essential oils under in vitro conditions from different plant species of family Lamiaceae, and their production is affected by culture conditions, cultivation mode, utilization of nutrient media and plant growth regulators. The literature survey suggests that essential oils obtained from family Lamiaceae have perspective for the development of new alternatives for disease treatment and prevention.     

香料前体香叶醇-β-D-葡萄糖苷的合成

报道了一种合成香叶醇葡萄糖苷的新方法。考察了糖苷化反应的多种影响因素（合成方法、反应温度、摩尔比）,得出最佳合成条件：采用相转移催化法,反应温度为60℃,反应物摩尔比n（溴代四乙酰葡萄糖：）n（香叶醇）为1.6∶1,反应时间为10 h,收率可达64%。该合成方法操作简单、反应条件温和、不污染环境,有较好的工业应用前景。     

Chemistryvis-à-vis maternalism in lace bugs (Heteroptera: Tingidae): Alarm pheromones and exudate defense inCorythucha andGargaphia species

The hawthorn lace bug,Corythucha cydoniae, and the eggplant lace bug,Gargaphia solani, possess alarm pheromones that are produced in dorsal abdominal glands (DAGs). WhenG. solani nymphs are grasped, they emit secretion from both DAGs; the posterior DAG secretion alone elicits alarm, but the anterior DAG secretion may hasten the response. InC. cydoniae, the response is due to a synergism between the anterior and posterior DAG secretions, and nymphs are apparently unable to voluntarily release their DAG secretions; both DAGs must be ruptured for the pheromone to escape. The alarm pheromones are interspecifically active in patterns matching the intraspecific activities. Compounds identified from tingid DAG secretions that are involved in the alarm messages are: (E)2-hexenal, (E)-4-oxo-2-hexenal, acetaldehyde, geraniol, and linalool. A new natural product of unknown function (designated nerolidol aldehyde) was identified from the anterior DAG secretions of both species.     

Mandibular Gland Secretion of <Emphasis Type="Italic">Melipona beecheii</Emphasis>: Chemistry and Behavior

The mandibular gland secretion of Melipona beecheii contains a rich mixture of terpenoid and oxygenated compounds and unsaturated and saturated hydrocarbons. However, it differs markedly from the 11 other Brazilian species examined in previous studies, both by the absence of 2-heptanol and the presence of rose oxides. The most abundant compound was geranyl hexanoate, whereas the most volatile compounds were cis- and trans-rose oxide and geraniol. The complete blend and five individual components found in the gland secretion were tested by electroantennography (EAG) and behavioral assays. The complete mandibular gland extract and geraniol elicited the strongest EAG responses, whereas these and farnesyl acetate induced the strongest attack response from workers. The role of the rose oxides remains to be elucidated, as they do not appear to play a major role as an alarm pheromone of this species.     

Kairomone from dandelion,Taraxacum officinale,attractant for scarab beetleAnomala octiescostata

The attraction of the scarab beetleAnomala octiescostata to dandelion,Taraxacum officinale, was demonstrated to be chemically mediated by a mixture ofcis-3-hexenyl acetate, benzaldehyde, phenylacetaldehyde, benzyl alcohol, phenethyl alcohol, phenylacetonitrile, and benzyl benzoate, in the ratio 4:8:14:3:5:19:11. Combination of the synthetic kairomone and sex pheromone (buibuilactone + japonilure, 8:2), significantly increased the total catches ofA. octiescostata. Catches of male (but not female) beetles were significantly higher with the kairomone-pheromone blend than with kairomone alone. The synergistic effect of the kairomone from dandelion on the attractiveness did not significantly differ from that of a food-type lure, anethol, geraniol, and phenethyl propionate (9:0.5:0.5). The latter combined with the synthetic sex pheromone resulted in better attraction of female (but not male)A. octiescostata than the sex pheromone alone.     

钒化合物催化芳樟醇酯化异构制取香叶醇、橙花醇

以钒化合物作催化剂与硼酸酯为介质组成催化体系,由芳樟醇异构制取香叶醇和橙花醇,分别考察了反应温度、时间、介质等因素对反应的影响。结果表明,在适宜的反应条件下,芳樟醇的转化率达 70. 8%,选择性 98. 2%。     

离子液体中脂肪酶催化合成乙酸香叶酯的研究

对脂肪酶在离子液体中催化香叶醇与乙酸乙烯酯转酯化反应生成乙酸香叶酯的过程进行了研究.考察了水活度、底物酯和醇物质量的比率、温度、离子液体和酶的重复利用对催化得率及催化反应初始速率的影响，其中离子液体的水活度采用水合盐对进行控制，而在考察离子液体和酶的重复利用时采用了未经分离酶的间歇反应的方法.结果表明,随着水活度增加酶在离子液体1-丁基-3-甲基-咪唑六氟磷酸盐中催化反应的初始速率的变化趋势呈钟形曲线.最优的催化反应条件为：水活度为0.28，底物酯和醇物质量比为9.42， 30 ℃.在重复利用12次后，离子液体体积和酶的催化活力都没有明显减少.