ELECTROPHORESIS
·
2019
·
IF 2.754
Yuan-Yuan Cui,Huan Yao,Cheng-Xiong Yang,Xiu-Ping Yan
Microporous organic networks (MONs) are a new class of porous materials synthesized via Sonogashira coupling reactions between organic building blocks. Here we report an in situ synthesis approach to fabricate MONs coated capillary column for high resolution GC separation of hydrocarbons. The McReynolds constant evaluation reveals the MONs coated capillary is a non-polar column. The MONs coated capillary column shows good resolution for GC separation of diverse important industrial hydrocarbons such as linear and branched alkanes, alkylbenzenes, pinene isomers, ethylbenzene and styrene, cyclohexane and benzene. The MONs coated capillary column gave a high column efficiency of 1542 plates per meter for hexane and good precision for replicate separations of the selected hydrocarbons with the RSDs of 0.2–0.3, 1.5–3.1, and 1.9–3.3% for retention time, peak height and peak area, respectively. The MONs coated capillary also offered better resolution than commercial Inert Cap-1 and Inert Cap-5 capillary columns for hexane and heptane isomers. These results reveal the potential of MONs as novel stationary phases in GC.
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NATURAL PRODUCT RESEARCH
·
2018
·
IF 1.928
Guo-Feng Mao,Xiao-Chang Mo,Hatem Fouad,Ghulam Abbas,Jian-Chu Mo
Utilisation of Anagrus nilaparvatae is a promising and effective method for planthoppers manipulation. Twenty-seven components of remote lemongrass (Cymbopogon distans) oil were identified by GC/MS and nine volatiles were selected for behavioural experiments. In this study, we noted that the remote lemongrass oil was attractive to female A. nilaparvatae at concentrations of 0.1 and 1 mg/L. α-Pinene, β-pinene, eucalyptol, carveol and D-carvone attracted female wasps in the dose-dependent bioassays. Blend 1 (a mixture of eucalyptol, D-carvone, carveol, α-pinene, and β-pinene with ratios of remote lemongrass oil volatiles of 625:80:11:5:3) attracted female wasps at 10 mg/L, while blend 2 (a mixture of the same five volatiles at the same loading ratio) attracted them at 0.1 and 1 mg/L. These results suggested that plant essential oils could be attractants for natural enemies to control pests. The ratios of volatiles in the mixtures affect the attractiveness of the synthetic mixtures.
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HOLZFORSCHUNG
·
2018
·Vol. 72
·期 11
·973-978
·
IF 2.079
Hui-Chao Hu,Tong Zeng,Shaokai Zhang,Lihui Chen,Liulian Huang,Yonghao Ni
A solvent-assisted and pyrogallol (PG)-protected headspace gas chromatography (HS-GC) method was developed to determine the pinene (α- and β-pinene) content in the kraft pulping black liquor (BL). Ethanol (EtOH) addition eliminated pinene’s micelles in BL by complete dissolution in the EtOH/BL medium. PG was applied to protect pinene from oxidation during the sample storage and measurement. The results showed that, with a 25% (v/v) of EtOH content and a 0.1 g of PG in 5-ml of sample solution, a rapid and stable pinene HS extraction can be obtained in 20 min at 80°C. The method has high precision with relative standard deviations within 4.2%. The sensitivity [limits of quantification (LOQ) are ~140 μg l −1 ] was high, and a good accuracy (recovery=96.0–104%) was typical for the pinene detection. The presented method is simple, rapid, accurate and is suitable for pinene quantification in biorefinery related processes and it leads to the preparation of high-value chemicals.
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LWT-FOOD SCIENCE AND TECHNOLOGY
·
2018
·
IF 3.129
Jia-jing Guo,Zhi-peng Gao,Jin-lan Xia,Mark A. Ritenour,Gao-yang Li,Yang Shan
In this work, the chemical composition, antimicrobial and antioxidant activities of fourteen species of citrus essential oils (EOs) from the main cultivated varieties in China were evaluated and compared. A total of more than 200 components were identified, which are mainly composed of terpenes, alcohols, aldehydes, esters, ketones and acids. Antimicrobial ability of fourteen EOs and seven major components were tested against six bacteria and two yeasts. The susceptibility of Gram-positive bacteria tested was observed to be greater than Gram-negative bacteria, and the yeasts tested were relatively more susceptive than bacteria. Three groups (Strong, Medium and Weak) were divided according to the antimicrobial ability. The EOs of Citrus Changshan huyou B. Chang and Citrus. medica var. sarcodactylis Swin exhibited the strongest antimicrobial activity against all tested strains. Linalool showed the strongest antimicrobial activity against all microorganisms except Pseudomonas aeruginosa . Three characters and tendencies were found out to correlate chemical composition with antimicrobial activity of different citrus essential oils. The EOs of Citrus aurantium L and Citurs medica var. sarcodactylis Swing showed strong ABTS radical scavenging, and the EOs of Citurs medica var. sarcodactylis Swing and Citrus Changshan huyou B. Chang exhibited strong free radical scavenging activity.
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JOURNAL OF CHEMICAL THERMODYNAMICS
·
2012
·
IF 2.422
Yao Chen,Hui Wang,Yanyan Tang,Jun Zeng
Ternary (liquid + liquid) equilibria date for the (water + 2-propanol + α -pinene, or β -pinene) systems were measured at T = (293.15, 298.15, 303.15, and 308.15) K under atmospheric pressure. The experimental results were correlated using the extended and modified UNIQUAC models. The calculated results obtained from the modified UNIQUAC model successfully represent the experimental tie-line data. The temperature influence on liquid-phase equilibria was studied.
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FOOD CHEMISTRY
·
2012
·
IF 3.655
Jiao Jiao,Yu-Jie Fu,Yuan-Gang Zu,Meng Luo,Wei Wang,Lin Zhang,Ji Li
An efficient enzyme-assisted microwave hydro-distillation (EAMHD) essential oil from Fructus forsythiae was investigated in the present study. Under optimal process conditions, the maximum extraction yield of the essential oil reached 3.27%, which increased by 39.15% and 45.33% more than those of normal microwave hydro-distillation (MHD) and traditional hydro-distillation (HD), respectively. GC/MS analysis revealed the presence of 21 compounds in Fructus forsythiae essential oil. Higher amounts of oxygenated monoterpenes were existed in the essential oil of EAMHD (26.47%) in comparison with MHD (22.37%) and HD (16.79%). Meanwhile, the antimicrobial and antioxidant activities were also assessed in vitro , EAMHD extracted essential oil exhibited relatively good antimicrobial activity with the minimum inhibitory concentration (MIC) values for all the susceptible microorganisms ranging from 0.78 to 6.25 mg/ml, and showed considerable linoleic acid oxidation inhibition (63.56%) in the β-carotene–linoleic acid bleaching assay. Furthermore, samples scanning electron micrographs illustrated the severely structural disruption of EAMHD.
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JOURNAL OF INSECT SCIENCE
·
2015
·Vol. 15
·期 1
·
IF 1.025
Wang Xuegui,Hao Qiang,Chen Yiqu,Jiang Surong,Yang Qunfang,Li Qing
The major chemical components of four essential oils (EOs) extracted from dry leaves of Citrus limonum , Cymbopogon citratus , Litsea cubeba, and Muristica fragrans were analyzed with gas chromatograph-mass spectrometer and their fumigant, contact, and repellent activities against 10th instar and adults of Tenebrio molitor were also assayed. The results indicated that the major constituents of C. limonum and Cy. citrates were D-limonene (38.22%) and 3,7-dimethyl-6-octenal (26.21%), while which of L. cubeba and M. fragrans were (E)-3, 7-dimethyl-2, 6-octadienal (49.78%) and (E)-cinnamaldehyde (79.31%), respectively. Contact activities of L. cubeba and C. limonum with LC 50 values of 21.2 and 13.9 µg/cm 2 at 48 h and repellence activities (>89.0% repellence indexes) ( P < 0.05) at 12 h on 10th instar were better than those of the other two EOs. Nevertheless, the fumigation activities of L. cubeba on 10th instar and adults (LC 50 = 2.7, 3.7 μl/liter) were stronger than those of C. limonum (LC 50 = 10.9, 12.0 μl/liter) at 96 h and significant (not overlapping confidence intervals). The EOs of L. cubeba and C. limonum have clearly elongated the growth and development of larvae, egg, and slightly shorten pupae and adults of T. molitor compared with the control. The mainly active ingredients of L. cubeba and C. limonum , including D-limonene and β-pinene, were demonstrated to coinhibit the actives of AChE and enhance the toxicities on 10th instar of T. molitor . These results indicate that the EOs of L. cubeba and C. limonum could have great potential as botanical insecticides against T. molitor .
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MICROPOROUS AND MESOPOROUS MATERIALS
·
2016
·
IF 3.349
Xing Chu,Dan Zhou,Dan Li,Kun Xia,Ning Gan,Xinhuan Lu,Renfeng Nie,Qinghua Xia
This work has firstly constructed purely Lewis acidic sites on MCM-41 successfully, for which Zr-MCM-41 catalysts with different Zr contents are prepared through the hydrolysis of ZrOCl 2 on MCM-41, followed by calcination . Thus-prepared materials possess typical hexagonal mesostructures, irregular morphologies, large surface areas, and large pore sizes, as revealed by XRD , SEM, TEM, N 2 adsorption, and DRIFT FTIR. UV–vis, Raman and XPS spectra prove the formation of isolated species in high dispersion on the surface of MCM-41. NH 3 -TPD analysis shows that the acid intensity of the catalysts is proportional to the content of Zr, and the acidity of Zr-MCM-41 with the Zr content of <0.5% is very weak. Pyridine-IR spectra show that the surface acidity is mainly consisted of Lewis acidity, and solely Lewis acidic sites are constructed on Zr-MCM-41(550) with a low Zr content < 0.5 wt%. More Lewis acidic sites exposed on the surface of Zr-MCM-41 are considerably important for promoting the titled Prins condensation.
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JOURNAL OF ESSENTIAL OIL RESEARCH
·
2013
·
IF 0.553
Xiao-Wei Huang,Yun-Chao Feng,Yi Huang,Hai-Ling Li
Litsea cubeba essential oil (LCEO) is widely used as a flavor enhancer in cosmetics and as a folk skin-care agent in southern China. The objective of this paper is to investigate whether LCEO has biological activities that might be useful in modern skin-protection formulations. The present study results revealed that citral (57.4%) was a major component, while LCEO exhibited a potent inhibitory effect on tyrosinase (IC50 values 100 μg/mL), good antioxidative activities (IC50: 17.75 mg/mL for ABTS+., 10.2 mg/mL for O2
−), and apparent protective effect against UV–TiO2–NO2
−-induced protein oxidation at 0.01 mg/mL and tyrosine nitration at 0.1 mg/mL. Additionally, the biological activities of LCEO were compared with that of its main constituents. The results demonstrated that any individual major component was not the unique contributor to the high activity of LCEO. Based on these results, we suggested that LCEO could serve as a new natural skin-whitening agent.
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PARASITOLOGY RESEARCH
·
2014
·Vol. 113
·期 10
·3631-3637
·
IF 2.327
Ma Wei-Bin,Feng Jun-Tao,Jiang Zhi-Li,Wu Hua,Ma Zhi-Qing,Zhang Xing
To seek natural products for the development of environment friendly mosquito control agents, fumigant activity of eleven essential oil compounds and the joint action of the active compounds were evaluated against Culex pipiens pallens adults. Fumigant bioassay demonstrated that carvacrol exhibited the highest fumigant activity followed by thymol and l-perillaldehyde, with LC 50 values of 0.26, 0.28, and 0.34 mg/L air, respectively. Among the binary mixtures of four compounds with preferable performance, only the binary mixture of carvacrol and thymol (1:1, w / w ) displayed a synergistic effect with the co-toxicity coefficient (CTC) value of 174.1 and LC 50 value of 0.16 mg/L air. Furthermore, the actual efficacy of the binary mixture at 300 mg/mat (KT 50 = 7.9, 15.8, and 22.0 min after 0, 2, and 4 h of preliminary heating, respectively) was comparable with that of d-allethrin at 30 mg/mat (KT 50 = 8.7, 17.9, and 21.2 min after 0, 2, and 4 h of preliminary heating, respectively) tested in vaporizing mats by the glass chamber method (70 × 70 × 70 cm). These results revealed that carvacrol, thymol, and their binary mixture have potential for the development of natural fumigants for adult mosquito control.
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Forests
·
2024
·Vol. 15
·期 2
·244
·
IF 2.4
Quanmin Wen,Ruixu Chen,Tian Xu,Dejun Hao
Conifers have evolved sophisticated terpenoid defenses for protection against herbivores and pathogens.Pinus massonianaLamb. is the most widely distributed pioneer afforestation and resin tree species in China, but is seriously harmed by pine wilt disease.Monochamus alternatusis the main vector of pine wilt disease in China. Monoterpenes, sesquiterpenes and diterpenes, the main secondary defensive compounds ofP. massoniana, are catalyzed by different terpene synthases (TPSs), which participate in the important defense pathways against external biotic and abiotic stresses. Here, we aimed to identify the terpene synthases (TPSs) inP. massoniana,responding to the feeding ofM. alternatus, and to characterize the functions and products of the mono-TPSs. We identified six differentially expressed TPS genes in theP. massonianafed upon byM. alternatus, including four mono-TPS and two sesqui-TPS genes. The functions of the four mono-TPSs were verified by analysis of the main product and by-products of these mono-TPSs. (+)-α-Pinene, (−)-α-pinene, and limonene were the major products of TPS (+)-α-pinene, TPS (−)-α-pinene, and TPS limonene, respectively, but TPS (−)-β-pinene only catalyzed a trace amount of (−)-β-pinene in the products. Our findings shed light on the potential relationships between the structure of terpene synthases and their corresponding products.
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FOOD CHEMISTRY
·
2025
·
IF 9.8
Wenbin Xiao,Jiajing Guo,Yanjiao Fu,Zixuan Li,Tongping Zhang,Mingwang He,Ting Liu,Yangbo Xiao,Xuebo Shang,Fuhua Fu,Gaoyang Li,Donglin Su,Zhipeng Gao,Yang Shan
The essential oil from Citrus changshan-huyou Y.B. Chang (HYEO) contains volatile compounds with strong inhibitory effects on biofilms formed on food processing equipment. This study analyzed the compositional changes of HYEO over 9 years and evaluated its antibacterial and antibiofilm properties. HYEO showed significant antibacterial activity during the first 8 years, effectively removing mature biofilms. Gas chromatography-mass spectrometry analysis revealed that monoterpenes were the primary components, with d -limonene and γ-terpenes converting into oxygenated derivatives during storage, resulting in a more than 16-fold increase in antibacterial activity. The antibacterial strength correlated with the number of oxygenated derivatives from limonene and terpinene among the top 20 components. Significant associations were observed between antibacterial activity and the oxygenated derivatives of d -limonene and γ-terpenes. These findings suggest the need for further investigation into their synergistic effects, antibacterial mechanisms, potential applications in food processing, and the safety profiles of the main antibacterial components of HYEO.
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