Two new triterpenoid saponins derived from the leaves of Panax ginseng and their antiinflammatory activity

Fuli Li,Yufeng Cao,Tingwu Liu,Guilong Yan,Liang Chen,Lilian Ji,Lun Wang,Bin Chen,Aftab Yaseen,Ashfaq A. Khan,Guo-Lin Zhang,Yunyao Jiang,Jianxun Liu,Gongcheng Wang,Ming-Kui Wang,Weicheng Hu 고려인삼학회 2019 Journal of Ginseng Research Vol.43 No.4

Background: The leaves and roots of Panax ginseng are rich in ginsenosides. However, the chemical compositionsof the leaves and roots of P. ginseng differ, resulting in different medicinal functions. In recent years,the aerial parts of members of the Panax genus have received great attention fromnatural product chemistsas producers of bioactive ginsenosides. The aim of this study was the isolation and structural elucidation ofnovel, minor ginsenosides in the leaves of P. ginseng and evaluation of their antiinflammatory activity in vitro. Methods: Various chromatographic techniques were applied to obtain pure individual compounds, andtheir structures were determined by nuclear magnetic resonance and high-resolution mass spectrometry,as well as chemical methods. The antiinflammatory effect of the new compounds was evaluated onlipopolysaccharide-stimulated RAW 264.7 cells. Results and conclusions: Two novel, minor triterpenoid saponins, ginsenoside LS1 (1) and 5,6-didehydroginsenoside Rg3 (2), were isolated from the leaves of P. ginseng. The isolated compounds 1and 2 were assayed for their inhibitory effect on nitric oxide production in LPS-stimulated RAW 264.7cells, and Compound 2 showed a significant inhibitory effect with IC50 of 37.38 mM compared with that ofNG-monomethyl-L-arginine (IC50 ¼ 90.76 mM). Moreover, Compound 2 significantly decreased secretionof cytokines such as prostaglandin E2 and tumor necrosis factor-a. In addition, Compound 2 significantlysuppressed protein expression of inducible nitric oxide synthase and cyclooxygenase-2. These resultssuggested that Compound 2 could be used as a valuable candidate for medicinal use or functional food,and the mechanism is warranted for further exploration.

Antioxidant enzyme activity and microRNA are associated with growth of Poa pratensis callus under salt stress

Luo Hongsong,Zhou Zhixiang,Song Guilong,Yao Hongxiang,Han Liebao 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.4

Kentucky bluegrass (Poa pratensis L.) is an important species of turfgrass that is commonly planted on golf courses and landscapes all over the world. It is sensitive to salt stress; however, details relating to its molecular mechanisms of salt resistance are not available. We, therefore, analyzed the changes in growth, antioxidant enzyme activity, and microRNA expression in the callus 1 week after treatment with 200 mM NaCl for 12 h, 24 h, 48 h, 96 h, and 144 h. The results demonstrated that callus growth declined and thiobarbituric acid-reactive substance production and cell membrane permeability increased. Treatment with salt increased ascorbate peroxidase, glutathione reductase, superoxide dismutase, catalase, peroxidase, and polyphenol oxidase activity. Changes in the expression levels of microRNAs were observed under salt treatment. The expression of miR162, miR173, miR391, miR408, miR773, and miR857 increased by 70% after 24 h of salt treatment, after which it declined to a level similar to that of the control. The expression level of miR775 and miR827 decreased by 20% after 24 h, and then further decreased by 80% after 144 h. The expression level of miR841 increased by 50% after 24 h of salt treatment, and then stabilized. In contrast, salt treatment increased the expression of the auxin response factors ARF6, ARF8, ARF10, and ARF16 in the callus from 12 to 144 h of salt treatment, during which the expression increased twofold. Gene expression analysis indicated that salt-responsive gene families were regulated by microRNAs in the callus under salinity stress. The activity of antioxidant enzymes is also changing. MiR841 is considered to be a positive regulator of antioxidant enzyme biosynthesis. The present investigation elucidates the manner in which P. pratensis responds to salt stress in the callus, and could be used to inform further studies on the molecular mechanisms of stress tolerance.

Two new triterpenoid saponins derived from the leaves of Panax ginseng and their antiinflammatory activity

Li, Fu,Cao, Yufeng,Luo, Yanyan,Liu, Tingwu,Yan, Guilong,Chen, Liang,Ji, Lilian,Wang, Lun,Chen, Bin,Yaseen, Aftab,Khan, Ashfaq A.,Zhang, Guolin,Jiang, Yunyao,Liu, Jianxun,Wang, Gongcheng,Wang, Ming-Kui The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.4

Background: The leaves and roots of Panax ginseng are rich in ginsenosides. However, the chemical compositions of the leaves and roots of P. ginseng differ, resulting in different medicinal functions. In recent years, the aerial parts of members of the Panax genus have received great attention from natural product chemists as producers of bioactive ginsenosides. The aim of this study was the isolation and structural elucidation of novel, minor ginsenosides in the leaves of P. ginseng and evaluation of their antiinflammatory activity in vitro. Methods: Various chromatographic techniques were applied to obtain pure individual compounds, and their structures were determined by nuclear magnetic resonance and high-resolution mass spectrometry, as well as chemical methods. The antiinflammatory effect of the new compounds was evaluated on lipopolysaccharide-stimulated RAW 264.7 cells. Results and conclusions: Two novel, minor triterpenoid saponins, ginsenoside $LS_1$ (1) and 5,6-didehydroginsenoside $Rg_3$ (2), were isolated from the leaves of P. ginseng. The isolated compounds 1 and 2 were assayed for their inhibitory effect on nitric oxide production in LPS-stimulated RAW 264.7 cells, and Compound 2 showed a significant inhibitory effect with $IC_{50}$ of $37.38{\mu}M$ compared with that of NG-monomethyl-L-arginine ($IC_{50}=90.76{\mu}M$). Moreover, Compound 2 significantly decreased secretion of cytokines such as prostaglandin $E_2$ and tumor necrosis factor-${\alpha}$. In addition, Compound 2 significantly suppressed protein expression of inducible nitric oxide synthase and cyclooxygenase-2. These results suggested that Compound 2 could be used as a valuable candidate for medicinal use or functional food, and the mechanism is warranted for further exploration.

Crystallization and Mechanical Properties of Glass Fiber Reinforced Polypropylene Composites Molded by Rapid Heat Cycle Molding

Aimin Zhang,Guoqun Zhao,Jialong Chai,Junji Hou,Chunxia Yang,Guilong Wang 한국섬유공학회 2020 Fibers and polymers Vol.21 No.12

The crystalline behavior and mechanical properties of PP/GF (glass fibers) composites molded by rapid heat cyclemolding (RHCM) and conventional injection molding (CIM) were compared. SEM, DSC and XRD were utilized to studycrystallization behavior of PP and PP/GF composites. Furthermore, universal testing machine was employed to investigatethe mechanical properties. Results proved that higher degree of crystallinity and larger crystal size can be obtained in RHCMin comparison to CIM. GF can induce more crystal nuclei and then reduce the crystal size due to shear stress which isgenerated in polymer matrix around fibers. Nucleating agent (NA) has a positive effect on refine grains. The average crystaldiameter of PP/NA/30 %GF is about 1.7 μm which is one-tenth of PP/30 %GF (14 μm) in RHCM. XRD tests illustrated thatα-form crystal is the main crystal type for PP and PP/GF composites in RHCM and CIM. However, there is a little β-formcrystal in RHCM for PP/GF composites without NA. NA accelerates the formation of α-form crystal and restrains theemergence of β-form crystal. The plastic parts obtained in RHCM exhibited higher strength and modulus compared with thatobtained in CIM for both tensile and flexural tests.

ELECTROCHEMICAL Co 3 O 4 NANOPOROUS THIN FILMS SENSOR FOR HYDROGEN PEROXIDE DETECTION

GUANG SHENG CAO,RUILIN WANG,PEILONG WANG,XIN LI,YUE WANG,JUNPING LI,GUILONG WANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.4

The nanoporous Co 3 O 4 thin ¯lms were prepared on indium tin oxide (ITO) glasses by anelectrodeposition method. The surface morphology and composition of the nanoporous Co 3 O 4¯lms were characterized by scanning electron microscopy (SEM), energy-dispersive X-rayanalysis (EDS) and X-ray photoelectron spectroscopy (XPS). The results show that the as-deposited nanoporous Co 3 O 4 ¯lm is constructed by many interconnected nano°akes withthickness of about 40 nm. The cyclic voltammetry (CV) measurement indicates that thenanoporous Co 3 O 4 ¯lms exhibit remarkable electrocatalytic activities for the hydrogen peroxide(H 2 O 2 ) reduction which shows that it is a good candidate to be employed as electrode materialsfor electrochemical sensing of H 2 O 2 . Further analysis indicated that the detection sensitivityof the sensor was 1.357 mA mM? 1 cm? 2 and the detection limit was estimated to be about0.2 mM.