摘要：
It is presented that the activated carbon was carboxylated with hydrogen peroxide and then acylated with 2-methylimidazole to prepare the porous carbon support with a surface imidazolated modification. Through the adsorption of phosphotungstic acid on the fundamental site of an imidazolyl group and then adjusting the acid strength with the ammonia molecule, a catalytic carbon material immobilized with ammonium phosphotungstate (AC-COIMO-NH(4)PW) was obtained, which was used to catalyze a one-pot reaction of convenient α-pinene and hydrogen peroxide to sobrerol. The bifunctional active site originated from the dual property of ammonium phosphotungstate, as the oxidant and acid presenting a cooperatively catalytic performance, which effectively catalyzes the tandem epoxidation-isomerization-hydration of α-pinene to sobrerol, in which the solvent effect of catalysis simultaneously exists. The sobrerol selectivity was significantly improved after the acid strength weakening by ammonia. Monomolecular chemical bonding and anchoring of ammonium phosphotungstate at the basic site prevented the loss of the active catalytic species, and the recovered catalyst showed excellent catalytic stability in reuse. Using acetonitrile as the solvent at 40 °C for 4 h, the conversion of α-pinene could reach 90.6%, and the selectivity of sobrerol was 40.5%. The results of five cycles show that the catalyst presents excellent stability due to the tight immobilization of ammonium phosphotungstate bonding on the imidazolized activated carbon, based on which a catalytic-cycle mechanism is proposed for the tandem reaction.
期刊：
Progress in Organic Coatings,2019年127:408-418 ISSN：0300-9440
通讯作者：
Li, Xiangzhou
作者机构：
[Liu, Yanxin; Zhou, Jun; Li, Xiangzhou; Wu, Zhiping; Qian, Wei] Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Qian, Wei] Guangdong Polytech Environm Protect Engn, Nanhai 528216, Foshan, Peoples R China.;[Li, Xiangzhou] State Key Lab Ecol Appl Technol Forest Area South, Changsha 410004, Hunan, Peoples R China.;[Liu, Yanxin] Changsha Univ Sci & Technol, Sch Chem & Bioengn, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Li, Xiangzhou] C;Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
关键词：
Tea saponin;CTS-IFRCs;Synergistic effects;Multi-stage gas phase flame-retardant mechanism;Pyrolysis kinetic performance
摘要：
Tea saponin intumescent flame-retardant coatings (TS-IFRCs) is a green and high-efficiency flame-retardant coating based on natural-based tea saponin (TS), and has been confirmed with superior flame retardancy. The present study determined and assessed the effects of TS on the flame-retardant mechanism in composite tea saponin intumescent flame-retardant coatings (CTS-IFRCs) through the analysis of TG-DSC, FT-IR, SEM-EDS and pyrolysis kinetics. It has been demonstrated from the results that TS, synergized with other components in CTS-IFRCs, has direct and significant impacts on the char layer microstructure, flame retardancy and pyrolysis performance, these influences contributed to the double effects of TS as a blowing agent in gas phase flame-retardant mechanism, and as a carbon agent in condensed phase flame-retardant mechanism. High synergistic effects of natural-based TS revealed in this study have provided effective theoretical basis for emerging environmentally friendly bio-based flame-retardant materials and explored a new way for the utilization of TS.
作者机构：
[Zhou, Jun; Hu, Wei; Deng, Jiao; Liu, Xin; Li, Xiangzhou; Wang, Liqun] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Li, Xiangzhou] Natl Engn Lab Appl Technol Forestry & Ecol South, Changsha 410004, Hunan, Peoples R China.;[Zhou, Jun; Li, Xiangzhou] Cent South Univ Forestry & Technol, Insititute Nat Prod Res & Dev, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Li, Xiangzhou] C;[Li, Xiangzhou] N;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;Natl Engn Lab Appl Technol Forestry & Ecol South, Changsha 410004, Hunan, Peoples R China.;Cent South Univ Forestry & Technol, Insititute Nat Prod Res & Dev, Changsha 410004, Hunan, Peoples R China.
摘要：
Litsea cubeba essential oil (LCEO) extracted from the fruit of the Litsea tree is a broad-spectrum bacteriostatic agent that has been used to treat ailments for thousands of years in China. The objective of our study was to assess the inhibitory effect of LCEO on Botrytis cinerea, a fungus that causes the putrification of fruits and vegetables. After being treated with 1.0% LCEO, the electrical conductivity of the fungal cells increased, and the contents of soluble reducing sugars and proteins slowly increased over treatment time. After being treated for 48 h with 1.0% LCEO, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images clearly showed damage to hyphae cells when compared with the normal growth of the control groups. Additional studies showed that the ergosterol content in the cell membrane significantly decreased with an increase in the LCEO concentration, and the electrophoretic bands of the proteins assayed using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis method significantly changed at different LCEO concentrations. LCEO damaged the cell membrane and changed the cell membrane permeability, leading to the changes in some components in the cytoplasm, such as soluble reducing sugars, proteins, and ergosterol. In general, the antimicrobial activity of LCEO is attributable to a unique pathway and involves a series of events both on the surface and within the cytoplasm of the fungal cell.
期刊：
NEW JOURNAL OF CHEMISTRY,2019年43(39):15736-15742 ISSN：1144-0546
通讯作者：
Li, Xiangzhou;Chen, Kai
作者机构：
[Li, XZ; Chen, Kai; Zhou, Huakang; Zhou, Jun; Shang, Yaxuan; Li, Xiangzhou] Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Zhou, Jun; Li, Xiangzhou] Cent South Univ Forestry & Technol, Inst Nat Prod Res & Dev, Changsha 410004, Hunan, Peoples R China.;[Chen, Kai] Cent S Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;[Chen, Kai] Peking Univ, State Key Lab Chem Oncogen, Shenzhen Grad Sch, Shenzhen 518055, Peoples R China.
通讯机构：
[Li, XZ; Chen, K; Li, Xiangzhou; Chen, Kai] C;[Chen, Kai] P;Cent South Univ Forestry & Technol, Sch Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;Cent South Univ Forestry & Technol, Inst Nat Prod Res & Dev, Changsha 410004, Hunan, Peoples R China.;Cent S Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.
摘要：
Viniferifuran is an important natural resveratrol dimer with antioxidant, antiviral, anti-inflammatory and other biological activities. In this paper, density functional calculations are carried out to study the antioxidant activity of viniferifuran systematically. The radical scavenging ability of viniferifuran was discussed in detail, thermodynamically and kinetically. All these results suggested that viniferifuran is a stronger antioxidant than resveratrol. These results are of great significance in better understanding the relationship between the antioxidant properties and structural design of antioxidants, and should also be beneficial for promoting the utilization of resveratrol derivatives.
摘要：
The purpose of this study was to improve the solubility of resveratrol (Res) by a self-microemulsifying drug-delivery system (SMEDDS). Through a solubility experiment, the pseudoternary phase diagram and ternary phase diagram were used to optimize the Res SMEDDS formula. The optimum formulation consisted of 5% IPM, 20% PEG400, and 65% Cremophor RH40. The water solubility, stability, in vitro release and antioxidant activity of the Res SMEDDS were characterized. The Res solubility in the SMEDDS was at least 1,000 times compared to that in water. The average droplet size of the microemulsion was 28.00+/-1.67 nm and uniform distribution. The Res SMEDDS should be stored at low temperature and in the dark to avoid light conditions. Res SMEDDS was able to improve the in vitro release rate of Res, and the in vitro release of Res from Res SMEDDS was significantly faster that of Res powder and unaffected by pH value of media. Antioxidant assays showed that antioxidant activities of Res in Res SMEDDS were unaffected compared to Res powder. Cytotoxicity study indicated that Res SMEDDS at the concentration of less than 100 muM was safe. These results demonstrated the potential use of Res SMEDDS for oral administration of Res.
摘要：
We isolated and purified polysaccharide from the Camellia oleifera Abel. seed cake (CCP) and studied its hypoglycemic activity in vitro. The molecular weight of CCP was 4736 Da and the monosaccharide molar composition ratio was: Xylose:Glucuronic acid:Galactosamine:Mannose = 10.9:4.4:2.6:1.8. The CCP contained conjugated proteins and belonged to acidic polysaccharide, which can promote the consumption of the glucose in the medium by HepG2 cells within the range of 0.125-0.500 mg/mL Relative consumption rate (RCR) of the glucose was the highest at 0.5 mg/ml., exceeded that of the metformin hydrochloride, as well as that of Tea Polysaccharide under the same concentration. A meaningful structure activity relationship (SAR) of hypoglycemia polysaccharides had established. This result suggests that CCP can be used as hypoglycemic medicine or health food. (C) 2018 Elsevier B.V. All rights reserved.
作者机构：
[李馨怡; 周军; 彭媚; 陈薇] College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China;State Key Laboratory of Ecological Applied Technology in Forest Area of South China, Changsha, 410004, China;[李馨怡] College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China, State Key Laboratory of Ecological Applied Technology in Forest Area of South China, Changsha, 410004, China
通讯机构：
[Zhou, J.] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, China
