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.     

Effect of Interfacial Activity of Eugenol and Eugenol Esters with Different Alkyl Chain Lengths on Inhibiting Sunflower Oil Oxidation

Effects of eugenol esters with different alkyl chain lengths and combinations of eugenol + eugenol esters on sunflower oil oxidation at 338, 358, and 378 K are evaluated by determining different kinetic parameters. Also, water content and reverse micelles size of sunflower oil samples are monitored during oxidation. Eugenyl acetate shows higher antioxidant activity than eugenol in sunflower oil, while eugenyl butyrate, eugenyl hexanoate, and eugenyl decanoate shows lower antioxidant activity than eugenol. Antioxidant activity of eugenol esters decreases by increasing their alkyl chain length. Eugenol shows a synergistic effect with eugenyl acetate and eugenyl butyrate on increasing the induction period and antioxidant activity values, while it shows an antagonistic effect with eugenyl hexanoate and eugenyl decanoate. Also, combinations of eugenol + eugenyl acetate, as well as, eugenol + eugenyl butyrate stabilize the reverse micelles at longer period of time (3263 min for eugenol + eugenyl acetate and 2900 min for eugenol + eugenyl butyrate) than eugenol (2750 min). In addition, eugenol + eugenyl acetate and eugenol + eugenyl butyrate decrease the magnitude of temperature-related effects on sunflower oil oxidation to the higher extent than eugenol did. Practical applications: Recent studies have suggested that the antioxidants with ability to locate at the active sites of lipid oxidation can efficiently reduce lipid oxidation in bulk oil. Despite a remarkable focus on antioxidant activity of eugenol, there is no information regarding improving its interfacial performance through esterification method. Also, there are few published data regarding the effects of esterified antioxidants on physicochemical changes during the oxidation of bulk oil. In this study, eugenol is esterified with anhydrides with different alkyl chain lengths to increase its accessibility to the active site of lipid oxidation, that is, water–oil interface of reverse micelles in sunflower oil. Effects of eugenol esters on stability of reverse micelles and critical reverse micelles concentration of lipid hydroperoxides have been investigated for the first time.     

Eugenol-Induced Autophagy and Apoptosis in Breast Cancer Cells via PI3K/AKT/FOXO3a Pathway Inhibition

The use of natural compounds is promising in approaches to prevent and treat cancer. The long-term application of most currently employed chemotherapy techniques has toxic side effects. Eugenol, a phenolic phytochemical extracted from certain essential oils, has an anti-cancer effect. The modulation of autophagy can promote either the survival or apoptosis of cancer cells. Triple-negative (MDA-MB-231) and HER2 positive (SK-BR-3) breast cancer cell lines were treated with different doses of eugenol. Apoptosis was detected by a flow-cytometry technique, while autophagy was detected by acridine orange. Real-time PCR and Western blot assays were applied to investigate the effect of eugenol on the gene and protein expression levels of autophagy and apoptotic genes. Treating cells with different concentrations of eugenol significantly inhibited cell proliferation. The protein levels of AKT serine/threonine kinase 1 (AKT), forkhead box O3 (FOXO3a), cyclin dependent kinase inhibitor 1A (p21), cyclin-dependent kinase inhibitor (p27), and Caspase-3 and -9 increased significantly in Eugenol-treated cells. Eugenol also induced autophagy by upregulating the expression levels of microtubule-associated protein 1 light chain 3 (LC3) and downregulating the expression of nucleoporin 62 (NU p62). Eugenol is a promising natural anti-cancer agent against triple-negative and HER2-positive breast cancer. It appears to work by targeting the caspase pathway and by inducing autophagic cell death.     

New Eugenol Derivatives with Enhanced Insecticidal Activity

Eugenol, the generic name of 4-allyl-2-methoxyphenol, is the major component of clove essential oil, and has demonstrated relevant biological potential with well-known antimicrobial and antioxidant actions. New O-alkylated eugenol derivatives, bearing a propyl chain with terminals like hydrogen, hydroxyl, ester, chlorine, and carboxylic acid, were synthesized in the present work. These compounds were later subjected to epoxidation conditions to give the corresponding oxiranes. All derivatives were evaluated against their effect upon the viability of insect cell line Sf9 (Spodoptera frugiperda), demonstrating that structural changes elicit marked effects in terms of potency. In addition, the most promising molecules were evaluated for their impact in cell morphology, caspase-like activity, and potential toxicity towards human cells. Some molecules stood out in terms of toxicity towards insect cells, with morphological assessment of treated cells showing chromatin condensation and fragmentation, which are compatible with the occurrence of programmed cell death, later confirmed by evaluation of caspase-like activity. These findings point out the potential use of eugenol derivatives as semisynthetic insecticides from plant natural products.     

13种生物源杀菌剂对华重楼灰霉病的防治

[目的]通过比较13种生物源杀菌剂对华重楼灰霉病的防治效果.为华重楼灰霉病的科学防治提供参考。[方法]在室内条件下基于菌丝生长抑制法测定了重楼灰霉病菌Botrytis cinerea ES1对13种生物源杀菌剂的敏感性,在田间条件下,评价了4种生物源杀菌剂对华重楼灰霉病防治效果[结果]0.3%丁子香酚可溶性液剂、1%蛇床子素水乳剂、3%中生菌素可湿性粉剂和0.5%苦参碱水剂对Botrytis cinerea ES1的菌丝生长有较好的抑制效果,其EC₅₀值均小于100 mg/L,在离体华重楼叶片上,4种药剂对华重楼灰霉病的保护作用在70%左右,田间防效在60%左右[结论]丁子香酚、蛇床子素、中生菌素和苦参碱对华重楼灰霉病菌B.cinerea ES1菌丝生长很好的抑制效果并且在田间对华重楼灰霉病的防治也表现良好,可用于华重楼灰霉病的预防,配合发病后的化学药剂一起使用。     

Biocatalytic Properties and Structural Analysis of Eugenol Oxidase from Rhodococcus jostii RHA1: A Versatile Oxidative Biocatalyst

Eugenol oxidase (EUGO) from Rhodococcus jostii RHA1 had previously been shown to convert only a limited set of phenolic compounds. In this study, we have explored the biocatalytic potential of this flavoprotein oxidase, resulting in a broadened substrate scope and a deeper insight into its structural properties. In addition to the oxidation of vanillyl alcohol and the hydroxylation of eugenol, EUGO can efficiently catalyze the dehydrogenation of various phenolic ketones and the selective oxidation of a racemic secondary alcohol—4‐(1‐hydroxyethyl)‐2‐methoxyphenol. EUGO was also found to perform the kinetic resolution of a racemic secondary alcohol. Crystal structures of the enzyme in complexes with isoeugenol, coniferyl alcohol, vanillin, and benzoate have been determined. The catalytic center is a remarkable solvent‐inaccessible cavity on the si side of the flavin cofactor. Structural comparison with vanillyl alcohol oxidase from Penicillium simplicissimum highlights a few localized changes that correlate with the selectivity of EUGO for phenolic substrates bearing relatively small p‐substituents while tolerating o‐methoxy substituents.     

有机硅改性丁香酚基环氧稀释剂的合成及性能研究

设计合成了一种低黏度有机硅改性的丁香酚基环氧稀释剂（HSEE）。首先以丁香酚和环氧氯丙烷为原料合成了丁香酚缩水甘油醚（ EE）然后 EE和 1,1,1,3,5,5,5-七甲基三硅氧烷（ HMTS）通过硅氢加成反应制备了 HSEE,并用核磁、红外对,HSEE进行了结构表征。将 HSEE与双酚 A型环氧树脂 E51进行复配,采用脂环胺类固化剂（ PACM）制备高固体分环氧清漆。结果表明： HSEE与环氧树脂 E51有着良好的相容性,共混时无相分离现象,且 E51树脂的黏度随着 HSEE含量的增加而不断降低,当添加量为 20%时,树脂的黏度从 12. 17 Pa·s降低至 1. 72 Pa·s。与纯 E51涂层相比,添加了 HSEE的环氧涂层的柔韧性、耐化学品性和耐腐蚀性能均有所提升。     

Eugenol β-Amino/β-Alkoxy Alcohols with Selective Anticancer Activity

Eugenol, 4-allyl-2-methoxyphenol, is the main constituent of clove essential oil and has demonstrated relevant biological activity, namely anticancer activity. Aiming to increase this activity, we synthesized a series of eugenol β-amino alcohol and β-alkoxy alcohol derivatives, which were then tested against two human cancer cell lines, namely gastric adenocarcinoma cells (AGS) and lung adenocarcinoma cells (A549). An initial screening was performed to identify the most cytotoxic compounds. The results demonstrated that three β-amino alcohol derivatives had anticancer activity that justified subsequent studies, having been shown to trigger apoptosis. Importantly, the most potent molecules displayed no appreciable toxicity towards human noncancer cells. Structure-activity relationships show that changes in eugenol structure led to enhanced cytotoxic activity and can contribute to the future design of more potent and selective drugs.     

Antibacterial and Antifouling Efficiency of Essential Oils-Loaded Electrospun Polyvinylidene Difluoride Membranes

Nanofibers have become a promising material in many industries in recent years, mainly due to their various properties. The only disadvantage of nanofibers as a potential filtration membrane is their short life due to clogging by bacteria in water treatment. The enrichment of nanofibers with active molecules could prevent these negative effects, represented by essential oils components such as Thymol, Eugenol, Linalool, Cinnamaldehyde and Carvacrol. Our study deals with the preparation of electrospun polyvinylidene difluoride (PVDF)-based nanofibers with incorporated essential oils, their characterization, testing their antibacterial properties and the evaluation of biofilm formation on the membrane surface. The study of the nanofibers’ morphology points to the nanofibers’ diverse fiber diameters ranging from 570 to 900 nm. Besides that, the nanofibers were detected as hydrophobic material with wettability over 130°. The satisfactory results of PVDF membranes were observed in nanofibers enriched with Thymol and Eugenol that showed their antifouling activity against the tested bacteria Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Therefore, these PVDF membranes could find potential applications as filtration membranes in healthcare or the environment.     

Bio-resourced eugenol derived phthalonitrile resin for high temperature composite

Eugenol (EG) is an abundant renewable compound that has been widely used in the synthesis of bio-based thermosetting resin, but there are few reports on the phthalonitrile (PN) resin derived from EG. In this study, a new kind of bio-based PN resin (MEG-PN) derived from EG derivative was successfully synthesized. PN is a traditional class of high-performance thermosets with poor processability for its ultra-high melting point and curing temperature. The MEG-PN resin possesses excellent processability: its melting temperature is much lower (77°C), and it can be cured at a moderate temperature (281°C) in the absence of curing agents. The cured MEG-PN resin exhibited great heat resistance according to its 5% weight loss temperature at 448°C and its char yield percentage as high as 75.6% at 800°C under nitrogen. The properties of the carbon-fiber reinforced MEG-PN composite were comparable to those of petroleum-based PN resins: the glass transition temperature was around 397°C; the flexural strength and modulus were as high as 756 MPa and 119 GPa, respectively. Overall, a bio-based PN thermoset with great comprehensive performance was synthesized possessing the potential in the application of advanced composite.     

Determination of eugenol diffusion through LLDPE using FTIR-ATR flow cell and HPLC techniques

A time-resolved Fourier Transform Infrared-Attenuated Total Reflectance Spectroscopy (FTIR-ATR) technique was set up and used to study the diffusion of eugenol through Linear Low Density Polyethylene (LLDPE) at 16, 23 and 40 °C. The 1514 cm⁻¹ peak for eugenol (aromatic -CC- stretching) was monitored over time and used to determine the diffusion coefficient (D). The Fickian model was found to fit well to the experimental data and the D value of eugenol through LLDPE was found to be between 1.05 ± 0.01 and 13.23 ± 0.18 × 10⁻¹⁰ cm²/s. The FTIR-ATR results were compared with one and two side diffusion process using a permeation cell and quantified by High Performance Liquid Chromatography (HPLC) technique. Eugenol sorbed in LLDPE samples at different times, was extracted in methanol and the concentration determined by HPLC. The diffusion coefficient by both two-sided and one-sided HPLC technique was found to be approximately three times higher than the FTIR-ATR values although they were in the same order of magnitude of 10⁻¹⁰ cm²/s. The difference between the FTIR-ATR and HPLC results was mainly attributed to difference between the two measuring techniques.     

丁香酚在活化玻碳电极上的电化学行为

用循环伏安法和差分脉冲溶出伏安法研究了丁香酚在活化玻碳电极于醋酸-醋酸钠（pH=6．0）缓冲溶液中的电化学行为。结果表明,丁香酚在该电极上于0．188V、0．485V有一对氧化还原峰,表明该电极对丁香酚有催化作用。在pH=6．0的醋酸-醋酸钠缓冲液中,用差分脉冲溶出伏安法在该电极上测定了丁香酚,线性范围为4．00×10^-6-2．58×10^-4mol／L。检测限为1．96×10^-6mol／L。成功用于样品的测定。     

Potential and Metabolic Pathways of Eugenol in the Management of Xanthomonas perforans,a Pathogen of Bacterial Spot of Tomato

Bacterial spot of tomato continues to pose a significant problem to tomato production worldwide. In Florida, bacterial spot of tomato caused by Xanthomonas perforans is one of the most important diseases responsible for tomato yield loss. This disease is difficult to control, and new strategies are continually being investigated to combat the devastating effect of this disease. Recent efforts focusing on essential oils based on small molecules have spurred interests in the utilization of this class of chemicals for disease management. In this study, we evaluated the efficacy of eugenol for the management of bacterial spot of tomato caused by X. perforans. In the greenhouse experiments, eugenol applied as a foliar spray significantly (p < 0.5) reduced bacterial spot disease compared to the untreated control. In the field experiments, the area under the disease progress curve (AUDPC) was significantly (p < 0.5) lower in the plots treated with eugenol or eugenol combined with the surfactant Cohere than in the untreated control plots, and it was comparable to the copper-based treatments. To provide additional insights into the possible pathways of eugenol activities, we applied a liquid chromatography mass spectrometry (LC-MS)-based metabolomic study using a thermo Q-Exactive orbitrap mass spectrometer with Dionex ultra high-performance liquid chromatography (UHPLC) on X. perforans strain 91–118 treated with eugenol. Our results showed that eugenol affected metabolite production in multiple pathways critical to bacterial survival. For example, treatment of cells with eugenol resulted in the downregulation of the glutathione metabolism pathway and associated metabolites, except for 5-oxoproline, which accumulation is known to be toxic to living cells. While the peaks corresponding to the putatively identified sarmentosin showed the most significant impact and reduced in response to eugenol treatment, branched-chain amino acids, such as L-isoleucine, increased in production, suggesting that eugenol may not negatively affect the protein biosynthesis pathways. The results from our study demonstrated the efficacy of eugenol in the management of bacterial spot of tomato under greenhouse and field conditions and identified multiple pathways that are targeted.     

Fabrication of Zein-Based Fibrous Scaffolds for Biomedical Applications—A Review

Zein, which accounts for around 80% of the total protein composition in corn, is a biocompatible and biodegradable substance derived from renewable sources. Although insoluble in water, its amphiphilic characteristics are utilized to generate nanoparticles, nanofibers, microparticles, and even films. Numerous recent studies have demonstrated the potential of zein as a prospective biomaterial to develop fibrous scaffolds for biomedical functions owing to its biocompatibility, fibrous formation, and encapsulating qualities. Fabrication of zein-based fibrous scaffolds for biomedical applications is achieved by a wide variety of techniques, including electrospinning, wet spinning, freeze drying, and additive manufacturing. This article overviews current advancements in manufacturing techniques for zein-based fibrous scaffolds. In addition, it summarizes the most recent biomedical applications and research activities utilizing zein-based fibrous scaffolds. Overall, zein is proposed as a potential biomaterial for the production of fibrous scaffolds that stimulate cell adhesion and proliferation in a number of exciting biomedical applications due to its biodegradability, biocompatibility, and other unique features related to its structure.     

Zeolitic imidazolate framework-8 (ZIF-8) for drug delivery: a critical review

Zeolitie imidazolate framework-8(ZIF-8),composed of Zn ions and imidazolate ligands,is a class of metal-organic frameworks,which possesses a similar structure as conventional aluminosilicate zeolites.This material exhibits inherent porous property,high loading capacity,and pH-sensitive degradation,as well as excep-tional thermal and chemical stability.Extensive research effort has been devoted 10 relevant research aspects ranging from synthesis methods,property characterization to potential applications of ZIF-8.This review focuses on the recent development of ZIF-8 synthesis methods and its promising appications in drug delivery.The potential risks of using ZIF-8 for drug delivery are also summarized.     

丁香酚乙醚的绿色合成及优化

以丁香酚为原料,碳酸二乙酯(DEC)为乙基化试剂,通过单分子亲核取代反应(SN1)制备合成丁香酚乙醚。通过筛选多种催化剂,最终确立了以K2CO3为催化剂采用精馏工艺合成丁香酚乙醚。以丁香酚乙醚的得率为标准,采用中心复合设计法工艺进行优化,考察了温度(X1)、K2CO3质量分数(X2)、n(DEC)∶n(丁香酚)(X3)、时间(X4)对丁香酚乙醚得率的影响,拟合得到多元二次方程;得出当反应温度177.5℃,K2CO3质量分数8.66%,n(DEC)∶n(丁香酚)=4.64∶1,反应时间6.38 h时,制备的丁香酚乙醚得率最高,达到93.8%。该路线为绿色合成方法,具有很好的工业化前景。     

Investigation of Ionic Liquids for the Separation of Butanol and Water

Abstract

With the continual rise in the cost of fossil fuel based energy, research into economic and sustainable alternatives is of increasing importance. One significant source of increased cost and demand is the consumption of fossil fuels for automotive fuels. While ethanol has received the most attention as a fuel additive; butanol could be a better direct fuel alternative owing to its physical properties and energy value when compared to ethanol. Commercial butanol is nearly exclusively produced from petroleum feedstocks currently; however, some recent interest has begun to refocus on its generation via fermentation. Unfortunately, this production is limited due to the nature of the process and the use of energy-intensive separation techniques. Ionic liquids are novel green solvents that have the potential to be employed as an extraction agent to remove butanol from the aqueous fermentation media. A hurdle to this potential is the limited availability of solubility data for ionic liquids. This research investigates the phase behavior of two ionic liquids, butanol, and water. Additionally, issues related to the implementation of the investigated ionic liquids are discussed.     

水处理电絮凝技术的研究进展与挑战

电絮凝是一种用于处理不同类型饮用水和废水有效的电化学方法,近年来由于其高效地处理大量难处理污染物的能力而受到了广泛的关注。它成功地处理了有机和无机污染物且同时却很少产生副产物。在过去的十年里大量的研究致力于利用电絮凝处理饮用水和废水,从受污染的地下水到受高度污染的炼油厂废水都是其处理范围。本文首先介绍了电絮凝的基本原理及优缺点并回顾了近年来有关电絮凝用于水处理的文献,重点关注当前在饮用水和废水中的具体应用方面取得的成功以及未来应用的潜力。随后分析了影响电絮凝效率的几个因素,最后指出最近的电絮凝大多集中在去除特定污染物的研究上,而没有关注开发模型或工业应用,并且如果能降低电絮凝的成本,此方法将会有一个巨大的突破。