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Chen Y.-K.,Yunnan Academy of Tobacco Science | Li X.-S.,Yunnan Academy of Tobacco Science | Li X.-S.,Yunnan Nationalities University | Yang G.-Y.,Yunnan Academy of Tobacco Science | And 3 more authors.
Journal of Asian Natural Products Research | Year: 2012

Three new phenolic compounds, nicotphenols A-C (1-3), together with 14 known phenols (4-17), were isolated from the leaves of Nicotiana tabacum. Their structures were established by means of spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1-3 were tested for their anti-HIV-1 activities and cytotoxicities. They all showed significant cytotoxic abilities and modest anti-HIV-1 activities, respectively. © 2012 Copyright Taylor and Francis Group, LLC.

Wang J.,Yunnan Academy of Tobacco Science | Qiu Y.,Yunnan Academy of Tobacco Science | Liu J.,Yunnan Academy of Tobacco Science
Advanced Materials Research | Year: 2012

To learn differences between Chinese domestic and imported paper-process reconstituted tobacco (RT), their physical properties and chemical components were tested systemically and in-depth. The results indicated that: (1) Domestic RT were generally similar to the imported on physical properties. There were just some slight differences in filling power, combustibility (domestic RT were better than the imported), and density (the imported slightly lowered than the former). And all products were advised to improve their water contents. (2) Imported RT were higher in contents of total sugar, reducing sugar, nicotine and protein than domestic samples, whereas lower in Potassium contents; (3) Although there were no significant differences in contents of volatile alkali and total non-volatile acid between domestic RT and imported RT, volatile acid contents of the former were lower than that of the latter. Also all pH value of samples was near equal and showed very weak acidic. (4) Contents of poly-phenol, chlorogenic acid, rutin and petroleum ether extract of imported RT were higher than that of domestic products, while cellulose contents were lower. (5) The overall high contents in total sugar, reducing sugar, nicotine, volatile acids, malic acid, total poly-phenols and petroleum ether extract, may be main factors of good taste and aroma of imported products. © (2012) Trans Tech Publications, Switzerland.

Gu W.,Yunnan University | Li X.,Yunnan Academy of Tobacco Science | Huang J.,Yunnan University | Meng Z.,Yunnan University | And 3 more authors.
Applied Microbiology and Biotechnology | Year: 2011

Ferulic acid decarboxylase (FADase) can catalyze the transformation of ferulic acid into 4-vinyl guaiacol via decarboxylation in microorganisms. In this study, a gene encoding FADase was first isolated from the bacterium Enterobacter sp. Px6-4 using degenerate primers and a genome walking technique. The putative encoding gene (fad) of FADase consists of 507-bp nucleotides, coding a polypeptide of 168 amino acid residues. In addition, a putative gene encoding the transcriptional regulator was identified from the upstream of the fad gene. The deduced peptide sequence of the FADase from Enterobacter sp. Px6-4 showed a 51.2-53.3% sequence identity to decarboxylases from other bacteria. The gene fad was successfully expressed in Escherichia coli BL21, and the recombinant FADase was purified as a protein of ca. 23 kDa with an optimal activity at pH 4.0 and 28°C. The purified FADase could convert ferulic acid to 4-vinyl guaiacol effectively, and its hydrolytic activity could be inhibited by Cu2+ (99%) and Hg2+ (99.5%). A phylogenetic analysis of the FADase protein from bacteria revealed several different clades. Our result provided a basis for further studies of the ferulic acid transformation pathway and for enhanced production of vanillin in the future. © 2010 Springer-Verlag.

Wang H.,Sun Yat Sen University | He P.,Sun Yat Sen University | He P.,Yunnan Academy of Tobacco Science | Yan H.,Sun Yat Sen University | And 2 more authors.
Sensors and Actuators, B: Chemical | Year: 2011

A novel indane based β-diketone with trifluorobutane in the contraposition, 5-acetylindane-4,4,4-trifluorobutane-1,3-dione (HAITFBD) and its europium(III) ternary complex, Eu(AITFBD)3phen, were designed and synthesized, where phen was 1,10-phenanthroline. The complex was characterized by IR, UV-visible, thermogravimetric analysis (TGA) and photoluminescence (PL) spectroscopy in details. The results show that the Eu(III) complex exhibits high thermal stability, wide and strong excitation bands from 300 nm to 425 nm when monitored at 611 nm, which matches well with the 380 nm-emitting InGaN chips. The complex exhibits intense red emission under excitation of near UV light due to the f-f transitions of the central Eu3+ ion. Based on the emission spectrum, the CIE chromaticity coordinates of the LED are calculated as x = 0.63 and y = 0.34, which is suitable to be used as an efficient red phosphor in fabrication of white LEDs. The fluorescence lifetime and the luminescence quantum yield were also measured. The lowest triplet state energy of the primary ligand AITFBD was measured to be 17,730 cm-1, higher than that of the lowest excitation state energy level of the central Eu3+ ion, 5D0, and this suggests that the photoluminescence of the complex is a ligand-sensitized luminescence process (antenna effect). Finally, a bright red light-emitting diode was fabricated by coating the Eu(AITFBD) 3phen complex onto a 380 nm-emitting InGaN chip. All the results indicate that Eu(AITFBD)3phen can be applied as a red component for fabrication of near ultraviolet-based white light-emitting diodes. © 2011 Elsevier B.V.

Shen Q.,Hunan University | Shen Q.,Yunnan Academy of Tobacco Science | Zhou L.,Hunan University | Yuan Y.,Hunan University | And 5 more authors.
Biosensors and Bioelectronics | Year: 2014

A novel homogenous fluorescent sensor for signal-on detection of Cu2+ has been developed based on intra-molecular G-quadruplex formed by DNA-templated click reaction and crystal violet (CV) as label-free signal reporter. The clickable DNA probe consists of two G-rich strands (A and B) bearing azide and alkyne group, respectively, and a template strand (C) locating two proximate reactants by pairing with A and B. The sequences of A and B are derived from asymmetric split of the G-quadruplex sequence (TTAGGG)4. In the presence of Cu2+, the whole G-quadruplex sequence A-B is generated by chemical ligation of A and B via copper ion-catalyzed alkyne-azide cycloaddition, then released from template by toehold strand displacement, and consequently forming a stable intra-molecular G-quadruplex, which binds with CV to generate a strong fluorescent signal. Oppositely, weak fluorescence was obtained without Cu2+ because of unstable intermolecular G-quadruplex formed by A and B and lack of lateral loop connection. Therefore, the Cu2+ can be sensitively and specifically detected by the fluorescence of the CV-stained G-quadruplex with a low detection limit of 65nM and a linear range of 0.1-3μM. This method rationally integrated the DNA-templated synthesis and G-quadruplex structure-switch, presenting a simple and promising approach for biosensor development. © 2013 Elsevier B.V.

Lu M.,Shanghai JiaoTong University | Han Z.,Yunnan Academy of Tobacco Science | Yao L.,Shanghai JiaoTong University
Journal of Applied Microbiology | Year: 2013

Aim: To evaluate the antimicrobial effects of essential oils (EOs) from cassia, basil, geranium, lemongrass, cumin and thyme, as well as their major components, against Phytophthora parasitica var. nicotianae; to investigate morphological changes in hyphae and sporangia in response to treatment with cinnamaldehyde; and to further evaluate potential biocontrol capacities against tobacco black shank under greenhouse conditions. Methods and Results: The results revealed that the extent of mycelial growth inhibition was primarily dependent on the composition and concentration of the EOs and the structure of individual compounds. Cinnamaldehyde had a significantly higher inhibitory effect on mycelial growth, formation of sporangia, and production and germination of zoospores in P. parasitica var. nicotianae in vitro, achieving complete inhibition of these phenotypes at 72, 36, 36 and 18 mg l-1, respectively. Scanning electron microscopic observations revealed that cinnamaldehyde can cause considerable morphological degenerations of hyphae and sporangia such as cytoplasmic coagulation, shrivelled mycelia and sporangia aggregates and swelling and lysis of mycelia and sporangia walls. In vivo assays with cinnamaldehyde demonstrated that this compound afforded protective effect against tobacco black shank under greenhouse conditions in susceptible tobacco plants. Conclusions: The results of in vitro and in vivo bioassays, together with SEM imaging of the microstructure of P. parasitica var. nicotianae supported the possibility of using cinnamaldehyde as a potent natural biofungicide in the greenhouse. Significance and Impact of the Study: This study provides a theoretical basis for the potential use of cinnamaldehyde as commercial agents or lead compounds that can be exploited as commercial biofungicides in the protection of tobacco plants from P. parasitica var. nicotianae infection. © 2013 The Society for Applied Microbiology.

Wang H.,Sun Yat Sen University | He P.,Yunnan Academy of Tobacco Science | Yan H.,Sun Yat Sen University | Shi J.,Sun Yat Sen University | Gong M.,Sun Yat Sen University
Inorganic Chemistry Communications | Year: 2011

A β-diketone, 4-imidazol-4,4,4-trifluorobutane-1,3-dione (HIDTFBD) and the corresponding europium(III) complex Eu(IDTFBD)3phen were designed and synthesized, where phen was 1,10-phenanthroline. The complex was characterized by IR, UV-visible, thermogravimetric analysis (TGA) and photoluminescence (PL) spectroscopy. Monitored at 610 nm, the Eu(III) complex exhibited a strong and wide excitation band between 320 and 420 nm due to the formation of a big π-conjugated system in the complex molecule. Under near UV-light excitation, the complex showed strong red emission of Eu3+ ion due to the 5D0-7FJ (J = 0-4) transitions. The fluorescence lifetime and the luminescence quantum yield were also measured. Finally, a bright red light-emitting diode was fabricated by coating the europium ternary complex onto an ~ 395 nm-emitting InGaN chip, and the LED exhibited appropriate CIE chromaticity coordinates in red area. All these results suggest that the Eu(III) complex is a promising candidate as red component for fabrication of near UV-based white light-emitting diodes. © 2011 Elsevier B.V.

Lu M.,Shanghai JiaoTong University | Han Z.,Yunnan Academy of Tobacco Science | Xu Y.,Yunnan Academy of Agricultural Sciences | Yao L.,Shanghai JiaoTong University
Journal of Microbiology and Biotechnology | Year: 2013

Essential oils are increasingly of interest for use as novel drugs acting as antimicrobial and antiviral agents. In the present study, we report the in vitro antiviral activities of 29 essential oils, extracted from Chinese indigenous aromatic plants, against the tobacco mosaic virus (TMV). Of these essential oils, those oils from ginger, lemon, tea tree, tangerine peel, artemisia, and lemongrass effected a more than 50% inhibition of TMV at 100 μg/ml. In addition, the mode of antiviral action of the active essential oils was also determined. Essential oils isolated from artemisia and lemongrass possessed potent inactivation and curative effects in vivo and had a directly passivating effect on TMV infection in a dose-dependent manner. However, all other active essential oils exhibited a moderate protective effect in vivo. The chemical constitutions of the essential oils from ginger, lemon, tea tree, tangerine peel, artemisia, and lemongrass were identified by gas chromatography and gas chromatography-mass spectrometry. The major components of these essential oils were α-zingiberene (35.21%), limonene (76.25%), terpinen-4-ol (41.20%), limonene (80.95%), 1,8-cineole (27.45%), and terpinolene (10.67%). The curative effects of 10 individual compounds from the active essential oils on TMV infection were also examined in vivo. The compounds from citronellal, limonene, 1,8-cineole, and α-zingiberene effected a more than 40% inhibition rate for TMV infection, and the other compounds demonstrated moderate activities at 320 μg/ml in vivo. There results indicate that the essential oils isolated from artemisia and lemongrass, and the individual compound citronellal, have the potential to be used as an effective alternative for the treatment of tobacco plants infected with TMV under greenhouse conditions. © The Korean Society for Microbiology and Biotechnology.

Li Z.,Yunnan Academy of Tobacco Science | Zhan D.-J.,Central South University | Wang J.-J.,Hongyunhonghe Tobacco Group Co. | Huang J.,Yunnan Academy of Tobacco Science | And 5 more authors.
Analyst | Year: 2013

Backgrounds existing in the analytical signal always impair the effectiveness of signals and compromise selectivity and sensitivity of analytical methods. In order to perform further qualitative or quantitative analysis, the background should be corrected with a reasonable method. For this purpose, a new automatic method for background correction, which is based on morphological operations and weighted penalized least squares (MPLS), has been developed in this paper. It requires neither prior knowledge about the background nor an iteration procedure or manual selection of a suitable local minimum value. The method has been successfully applied to simulated datasets as well as experimental datasets from different instruments. The results show that the method is quite flexible and could handle different kinds of backgrounds. The proposed MPLS method is implemented and available as an open source package at http://code.google.com/p/mpls. © 2013 The Royal Society of Chemistry.

Duan Y.L.,Yunnan Normal University | Shi Y.G.,Yunnan Normal University | Chen J.H.,Yunnan Academy of Tobacco Science | Wu X.H.,Yunnan Normal University | And 3 more authors.
Tetrahedron Letters | Year: 2012

A 1,8-naphthyridine modified rhodamine B derivative (1) has been designed and synthesized. Compound 1 is the first 1,8-naphthyridine-modified rhodamine B sensor that can detect Cu 2+ selectively with a dramatic color change from colorless to pink. The complex of 1 and Cu 2+ was utilized as a chemosensing ensemble for cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) detection, which showed highly sensitive and selective colorimetric response to Cys, Hcy, and GSH among the tested naturally occurring α-amino acids in EtOH-HEPES (0.02 M, pH 7.4) (3:7, v/v) buffer solution. © 2012 Elsevier Ltd. All rights reserved.

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