Preparation of minor ginsenosides C-Mc, C-Y, F2, and C-K from American ginseng PPD-ginsenoside using special ginsenosidase type-I from Aspergillus niger g.848

Chun-Ying Liu,Rui-Xin Zhou,Chang-Kai Sun,Ying-Hua Jin,Hong-Shan Yu,Tian-Yang Zhang,Long-Quan Xu,Feng-Xie Jin 고려인삼학회 2015 Journal of Ginseng Research Vol.39 No.3

Background: Minor ginsenosides, those having low content in ginseng, have higher pharmacological activities. To obtain minor ginsenosides, the biotransformation of American ginseng protopanaxadiol (PPD)-ginsenoside was studied using special ginsenosidase type-I from Aspergillus niger g.848. Methods: DEAE (diethylaminoethyl)-cellulose and polyacrylamide gel electrophoresis were used in enzyme purification, thin-layer chromatography and high performance liquid chromatography (HPLC) were used in enzyme hydrolysis and kinetics; crude enzyme was used in minor ginsenoside preparation from PPD-ginsenoside; the products were separated with silica-gel-column, and recognized by HPLC and NMR (Nuclear Magnetic Resonance). Results: The enzyme molecular weight was 75 kDa; the enzyme firstly hydrolyzed the C-20 position 20- O-b-D-Glc of ginsenoside Rb1, then the C-3 position 3-O-b-D-Glc with the pathway Rb1/Rd/F2/C-K. However, the enzyme firstly hydrolyzed C-3 position 3-O-b-D-Glc of ginsenoside Rb2 and Rc, finally hydrolyzed 20-O-L-Ara with the pathway Rb2/C-O/C-Y/C-K, and Rc/C-Mc1/C-Mc/C-K. According to enzyme kinetics, Km and Vmax of MichaeliseMenten equation, the enzyme reaction velocities on ginsenosides were Rb1 > Rb2 > Rc > Rd. However, the pure enzyme yield was only 3.1%, so crude enzyme was used for minor ginsenoside preparation. When the crude enzyme was reacted in 3% American ginseng PPD-ginsenoside (containing Rb1, Rb2, Rc, and Rd) at 45C and pH 5.0 for 18 h, the main products were minor ginsenosides C-Mc, C-Y, F2, and C-K; average molar yields were 43.7% for CMc from Rc, 42.4% for C-Y from Rb2, and 69.5% for F2 and C-K from Rb1 and Rd. Conclusion: Four monomer minor ginsenosides were successfully produced (at low-cost) from the PPDginsenosides using crude enzyme.

Over-expression of SlWRKY39 leads to enhanced resistance to multiple stress factors in tomato

Xiao-chun Sun,Yong-feng Gao,Hui-rong Li,Shu-zhang Yang,Yong-sheng Liu 한국식물학회 2015 Journal of Plant Biology Vol.58 No.1

The WRKY transcription factors are one of the well-characterized classes of plant transcription factors, which participated in various biotic and abiotc stress responses. Previous study showed that there are 81 WRKY genes in tomato, wherein a number of SlWRKY genes including SlWRKY39 were significantly up-regulated under salt, drought stress and PstDC3000 infection. However little is known about their physiological role in tomato. In this study, by using a forward genetic approach, we demonstrated transgenic plants over-expressing SlWRKY39 showing enhanced resistance to multiple stress factors including PstDC3000, salt and drought. Transgenic plants accumulated higher level of proline and lower level of malonic dialdehyde. Compared with wild type, the expression of pathogenesis-related genes SlPR1, SlPR1a1 and environmental stress related genes SlRD22, SlDREB2A were up-regulated in the transgenic plants. These results indicated that SlWRKY39 is a positive regulatory component of tomato against biotic and abiotic stress probably via activating the expression of both pathogenesis-related genes and stress related genes.

Preparation and Properties of Green Environment-Friendly Drilling Polymer Mud

Zhang, Feng-Jun,Sun, Xian-Yang,Li, Xuan,Kong, Cui,Liu, Jin,Chen, Qian-Bao,Oh, Won-Chun Materials Research Society of Korea 2019 한국재료학회지 Vol.29 No.11

In this paper, a water-based green polymer mud is synthesized by simple compounding method. Effects of different kinds of tackifiers, their molecular weight on the viscosity of polymer mud and the effects of different fluid loss additives on mud fluid loss are studied. The results show that when polystyrene and anionic polyacrylamide with molecular weight of 8 ~ 10 million are used as the main thickening ingredient, polymer mud with high viscosity and high stability can be obtained. When the prepared polymer mud is formulated as NPAM: PEO: Hydroxypropyl cellulose(HPC) : Water = 42:10:10:100000 (unit: kg), the viscosity can reach 20.6 s, the filtration loss in 7.5 min is 24 mL, and the sand content is only 0.1 %. Compared with traditional bentonite mud, the green environment-friendly polymer mud has the advantages of small amount of waste, low environmental pollution, and low pulping cost, and can meet the construction needs for most topography and geomorphology drilling engineering.

Synthesis and Characterization of MoS₂/Graphene-TiO₂ Ternary Photocatalysts for High-Efficiency Hydrogen Production under Visible Light

Zhang, Feng-Jun,Kong, Cui,Li, Xuan,Sun, Xian-Yang,Xie, Wen-Jie,Oh, Won-Chun The Korean Ceramic Society 2019 한국세라믹학회지 Vol.56 No.3

Ternary MoS₂/graphene (G)-TiO₂ photocatalysts were prepared by a simple hydrothermal method. The morphology, phase structure, band gap, and catalytic properties of the prepared samples were investigated by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, UV-vis spectrophotometry, and Brunauer-Emmett-Teller surface area measurement. The H₂ production efficiency of the prepared catalysts was tested in methanol-water mixture under visible light. MoS₂/G-TiO₂ exhibited the highest activity for photocatalytic H₂ production. For 5 wt.% and 1 wt.% MoS₂ and graphene (5MT-1G), the production rate of H₂ was as high as 1989 µmol^-1h^-1. The catalyst 5MT-1G showed H₂ production activity that was ~ 11.3, 5.6, and 4.1 times higher than those of pure TiO₂, 1GT, and 5MT, respectively. The unique structure and morphology of the MoS₂/G-TiO₂ photocatalyst contributed to its improved hydrogen production efficiency under visible light.

Preparation of minor ginsenosides C-Mc, C-Y, F2, and C-K from American ginseng PPD-ginsenoside using special ginsenosidase type-I from Aspergillus niger g.848

Liu, Chun-Ying,Zhou, Rui-Xin,Sun, Chang-Kai,Jin, Ying-Hua,Yu, Hong-Shan,Zhang, Tian-Yang,Xu, Long-Quan,Jin, Feng-Xie The Korean Society of Ginseng 2015 Journal of Ginseng Research Vol.39 No.3

Background: Minor ginsenosides, those having low content in ginseng, have higher pharmacological activities. To obtain minor ginsenosides, the biotransformation of American ginseng protopanaxadiol (PPD)-ginsenoside was studied using special ginsenosidase type-I from Aspergillus niger g.848. Methods: DEAE (diethylaminoethyl)-cellulose and polyacrylamide gel electrophoresis were used in enzyme purification, thin-layer chromatography and high performance liquid chromatography (HPLC) were used in enzyme hydrolysis and kinetics; crude enzyme was used in minor ginsenoside preparation from PPD-ginsenoside; the products were separated with silica-gel-column, and recognized by HPLC and NMR (Nuclear Magnetic Resonance). Results: The enzyme molecular weight was 75 kDa; the enzyme firstly hydrolyzed the C-20 position 20-O-${\beta}$-D-Glc of ginsenoside Rb1, then the C-3 position 3-O-${\beta}$-D-Glc with the pathway $Rb1{\rightarrow}Rd{\rightarrow}F2{\rightarrow}C-K$. However, the enzyme firstly hydrolyzed C-3 position 3-O-${\beta}$-D-Glc of ginsenoside Rb2 and Rc, finally hydrolyzed 20-O-L-Ara with the pathway $Rb2{\rightarrow}C-O{\rightarrow}C-Y{\rightarrow}C-K$, and $Rc{\rightarrow}C-Mc1{\rightarrow}C-Mc{\rightarrow}C-K$. According to enzyme kinetics, $K_m$ and $V_{max}$ of Michaelis-Menten equation, the enzyme reaction velocities on ginsenosides were Rb1 > Rb2 > Rc > Rd. However, the pure enzyme yield was only 3.1%, so crude enzyme was used for minor ginsenoside preparation. When the crude enzyme was reacted in 3% American ginseng PPD-ginsenoside (containing Rb1, Rb2, Rc, and Rd) at $45^{\circ}C$ and pH 5.0 for 18 h, the main products were minor ginsenosides C-Mc, C-Y, F2, and C-K; average molar yields were 43.7% for C-Mc from Rc, 42.4% for C-Y from Rb2, and 69.5% for F2 and C-K from Rb1 and Rd. Conclusion: Four monomer minor ginsenosides were successfully produced (at low-cost) from the PPD-ginsenosides using crude enzyme.

Modification of a Smoking Motivation Questionnaire for Chinese Medical Students

Jiang, Chao,Sun, Wen-Jie,Wan, Yan-Chun,Wei, Ming-Wei,Mu, Yong-Ping,Tarver, Siobhan L.,Gao, Yong-Qing,Hu, Tian,Xu, Chao,Gordon, James,Feng, Cindy Xin,Wen, Yu-Feng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Introduction: Smoking prevalence among the medical students is high in China. Therefore, understanding the smoking motivations of medical students is crucial for smoking control, but currently there are no scales questionnaires customized for probing the smoking motivations of medical students. This aim of study was to test and modify a questionnaire for investigating smoking motivations among medical students. Methods: A cross-sectional survey was conducted among 1,125 medical students at Xuzhou Medical College in China in 2012.The model fit and validity was assessed by confirmatory factor analysis (CFA) and the reliability was tested by single-item reliability, composite reliability, and item-total correlation. Results: The prevalence of smoking was 9.84 % among study population. In the modified scales, the global fit indices identified a CFI value of 0.96, TLI was 0.96, and the RMSEA was 0.063. CFA supported the two dimensional structure of the instrument. The average variance extracted ranged from 0.45 to 0.62. All single-item reliability scores were greater than 0.20, and the composite reliability ranged from 0.74 to 0.91. Conclusion: Modified scales could be the preliminary instrument used in evaluating the smoking motivations of medical students. However, it should be further assessed using other forms and methods of validity and reliability, additional motivations of smoking, and the survey of other medical colleges in China.

A simple model for describing the effect of temperature on insect developmental rate

Peijian Shi,Feng Ge,Yucheng Sun,Chunli Chen 한국응용곤충학회 2011 Journal of Asia-Pacific Entomology Vol.14 No.1

The linear and Logan models are usually used to describe the effect of temperature on insect developmental rate. The linear model is often used to estimate the lower developmental threshold. However, it cannot be used to calculate the upper developmental threshold. Additionally, it fails to describe developmental rates near, at, and above the optimal developmental temperature. The Logan model can reflect temperaturedependent developmental rates from the lower to upper developmental thresholds. It is often used to compute the optimal developmental temperature and the upper developmental threshold, but it is not used to compute the lower developmental threshold. To avoid the disadvantages of these two models, we develop a new model, the ‘performance model’ on the basis of the impact of increasing temperature on enzyme activity and denaturation. The performance model was first used by Huey and Stevenson (Amer. Zool. 19,357–366) to provide a statistical description of the impact of body temperature on performance, but they did not provide underlying physiological mechanisms. Few studies have used the performance model to analyze the temperature-dependent developmental rates of insects, perhaps because of the lack of a theoretical justification. Here, we provide a theoretical justification to use the model and we use the performance model to evaluate the developmental rate data of two insect species. We found that the performance model has advantages over the linear and Logan models, and that the lower and upper developmental thresholds can be simultaneously obtained from this model.

Neuroprotective effect of miR‑410‑3p against sevoflurane anesthesia‑induced cognitive dysfunction in rats through PI3K/Akt signaling pathway via targeting C–X–C motif chemokine receptor 5

Rui Su,Ping Sun,Dianhong Zhang,Wei Xiao,Chun Feng,Liang Zhong 한국유전학회 2019 Genes & Genomics Vol.41 No.10

Background Postoperative cognitive dysfunction (POCD) is a neurodegenerative disorder with impairment of cognition. Sevoflurane anesthesia has been found to lead to CD and microRNAs (miRNAs) were reported to affect cognitive function. This study investigates the neuroprotective effect against sevoflurane anesthesia-induced CD. Methods HE staining was used to detect the pathological change of hippocampal neuron. Morris water maze test was used to analyze latency time, platform crossing and swimming speed. Quantitative real-time PCR (qRT-PCR) and western blotting were performed to examine the mRNA and protein expression of miR-410-3p, IL-6, TNF-α, IL-1β and C–X–C motif chemokine receptor 5 (CXCR5). Dual-luciferase reporter assay was used to detect the relationship between miR-410-3p and CXCR5. Results MiR-410-3p was downregulated in sevoflurane anesthesia-induced rats and cells and act as a suppressor in sevoflurane anesthesia-induced hippocampal neuron apoptosis and inflammation. Furthermore, miR-410-3p was identified to bind with CXCR5. Further analysis showed that CXCR5 expression was increased by sevoflurane treatment, whereas was repressed by miR-410-3p overexpression. Moreover, miR-410-3p could inhibit sevoflurane anesthesia-induced hippocampal neuron apoptosis by phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway. Conclusion These data indicated that miR-410-3p exhibited its neuroprotective effect on sevoflurane anesthesia-induced CD by targeting CXCR5 via PI3K/Akt signaling pathway. Our study may potentially provide a new light on the pathogenesis and therapeutic method for sevoflurane anesthesia-induced CD.

Simulation of the Structural Parameters of Anti-resonant Hollow-core Photonic Crystal Fibers

Qing Liu,Yujun Feng,Yinhong Sun,Zhe Chang,Yanshan Wang,Wanjing Peng,Yi Ma,Chun Tang 한국광학회 2022 Current Optics and Photonics Vol.6 No.2

Anti-resonant hollow-core photonic crystal fiber (AR-HCF) has unique advantages, such as low nonlinearity and high damage threshold, which make it a promising candidate for high-power laser delivery at distances of tens of meters. However, due to the special structure, optical properties such as modefield profile and bending loss of hollow-core fibers are different from those of solid-core fibers. These differences have limited the widespread use of AR-HCF in practice. In this paper we conduct numerical analysis of AR-HCFs with different structural parameters, to analyze their influences on an AR-HCF’soptical properties. The simulation results show that with a 23-μm air-core diameter, the fundamentalmode profile of an AR-HCF can well match that of the widely used Nufern’s 20/400 fiber, for nearlysingle-mode power delivery applications. Moreover, with the ratio of cladding capillary diameter to aircore diameter ranging from 0.6 to 0.7, the AR-HCF shows excellent optical characteristics, including low bending sensitivity while maintaining single-mode transmission at the same time. We believe these results lay the foundation for the application of AR-HCFs in the power delivery of high power fiber laser systems.

Bioactivity of essential oil of Litsea cubeba from China and its main compounds against two stored product insects

Kai Yang,Cheng FangWang,Chun Xue You,Zhu Feng Geng,Rui Qi Sun,Shan Shan Guo,Shu Shan Du,Zhi Long Liu,Zhi Wei Deng 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.3

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oilof Litsea cubeba fruits was found to possess strong contact toxicity against the cigarette beetle Lasiodermaserricorne adults and the booklouse Liposcelis bostrychophila, with LD50 values of 27.33 μg/adult and71.56 μg/cm2, respectively, and also showed strong fumigant toxicity against the two stored product insectswith LC50 values of 22.97 and 0.73 mg/L, respectively. The essential oil obtained by hydrodistillation wasinvestigated by GC MS. The main components of the essential oil were identified to be E-citral (geranial)(27.49%), Z-citral (neral) (23.57%) and D-limonene (18.82%) followed by β-thujene (3.34%), β-pinene (2.85%), α-pinene (2.57%), 6-methyl-5-hepten-2-one (2.40%) and linalool (2.36%). Citral (Z/E-citral), D-limonene, β-pinene,α-pinene and linalool were separated and purified by silica gel column chromatography and preparative thinlayer chromatography, and further identified by means of physicochemical and spectrometric analysis. Citral andlinalool showed strong contact toxicity against L. serricorne and L. bostrychophila (LD50 = 11.76, 12.74 μg/adultand 20.15, 99.97 μg/cm2, respectively) and fumigant toxicity against L. serricorne and L. bostrychophila (16.54,18.04 mg/L air and 0.14, 0.71 mg/L air, respectively). Otherwise, citral, D-limonene and linalool were strongly repellentagainst the cigarette beetle L. serricorne as the essential oil whereas β-pinene and α-pinene exhibited weakerrepellency against the cigarette beetle compared with the positive control, DEET. Moreover, except α-pinene andlinalool, the other three compounds as well as the essential oil exhibited comparable repellency against thebooklouse relative to DEET.