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Xi-xiang Ying,Hai-bo Li,Zheng-yun Chu,Yan-jun Zhai,Ai-jing Leng,Xun Liu,Wen-jie Zhang,Ting-guo Kang,Chun Xin 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.7
To investigate the antioxidant effect of vitexin-4"-O-glucoside, a flavone glycoside, isolated from the leaves of Crataegus pinnatifida Bge. var. major, we developed a simple and sensitive high-performance liquid chromatography (HPLC) method to determine levels of malondialdehyde (MDA) in ECV304 cell culture medium after induction by tert-butyl-hydroperoxide (TBHP). The preparation of analyzed samples involved a one-step derivatization with thiobarbituric acid (TBA). HPLC analysis was performed on a SynergiTM Hydro-RP, a polar end-capped C18 column (250×4.6 mm, 4 μm), using an acetonitrile-ammonium acetate aqueous solution (10 mM, pH 6.8) as the mobile phase under linear gradient conditions with UV detection at 532 nm. The calibration curve was linear over 0.0125-1.25 μM MDA (r = 0.9951). Relative standard deviations (RSDs) of intra-day and inter-day precision were less than 6.1% and 5.0%, respectively. The mean recovery was 96.9 ± 1.6%. The lower limit of quantification (LLOQ) of MDA was 0.0125 μM. This chromatographic method was successfully applied to investigating the in vitro antioxidant effect of vitexin-4"-O-glucoside. Vitexin-4"-O-glucoside (120 M) protected ECV304 cells from peroxidation induced by TBHP.
Kang, Yiran,Li, Xiao-Xi,Cho, Kyung-Bin,Sun, Wei,Xia, Chungu,Nam, Wonwoo,Wang, Yong American Chemical Society 2017 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.139 No.22
<P>Although nonheme iron(III)iodosylarene complexes present amazing oxidative efficiency and selectivity, the nature of such complexes and related oxidation mechanism are still unsolved after decades of experimental efforts. Density functional calculations were employed to explore the structurereactivity relationship of the iron(III)iodosylbenzene complex, [Fe-III(tpena(-)) (PhIO)](2+) (1), in thioanisole sulfoxidation. Our theoretical work revealed that complex 1 can evolve into two resonance valence-bond electronic structures (a high-valent ironoxo species and a monomeric PhIO species) in thioanisole sulfoxidation to present different reaction mechanisms (the novel bond-cleavage coupled electron transfer mechanism or the direct oxygen-atom transfer mechanism) as a response to different substrate attack orientations.</P>
중국 Changzhou댐의 방수로 운용에 따른 어류밀도와 분포에 관한 음향조사
( Xi Chang Tan ),강명희 ( Myoung Hee Kang ),( Jiang Ping Tao ),( Xin Hui Li ),( Dao Ming Huang ) 한국수산과학회(구 한국수산학회) 2011 한국수산과학회지 Vol.44 No.4
Hydroacoustic surveys were performed to clarify the density and spatial distribution of fish upstream and downstream of Changzhou Dam in the Pearl River, China, with regard to the condition of the spillways. Fish were densely distributed in the forebay of the upstream dam and the average fish density was 0.22 individuals/㎥ under open spillways on 24 June 2010, but when the spillways were closed on 25 June 2010, the fish in the upstream dam dispersed and the average fish density decreased to 0.007 individuals/㎥. Meanwhile, the average fish density in the downstream region was 0.28 individuals/㎥ before the spillway was opened on 24 May 2010, but it decreased to 0.08 individuals/㎥ on 26 June, just after the spillway was closed. The vertical distribution of fish upstream of the dam was not consistent. The target strength (TS) of fish upstream of the dam was larger than that of fish in the downstream region, although the distribution of TS was similar between the upstream and downstream regions. Therefore, we concluded that while numerous fish could swim to the upstream region while the spillways were open, closed spillways obstructed fish migrating upward from the downstream region.
Lin Xi Cai,조종운,Yan Zhao,Jong-Seong Kang,Kyung Tae Kim,Sang-Hun Jung 한국분석과학회 2019 분석과학 Vol.32 No.2
The simple and effective analytical method for the quality control of a novel scalp tonic formulation has been developed and optimized in terms of HPLC conditions and sample preparation method, meanwhile, the optimization of preparation condition was using response surface methodology (RSM) based on central composite design (CCD). Oleanolic acid was selected as marker compound because of its bioactivities for alopecia therapy. The developed analytical method and extraction condition were successfully qualified. Coefficient of determination (r2) for the calibration was 0.9997 with a line passing through the origin point in the range of 0.1-100 mg/mL. The limit of detection (LOD) and the limit of quantitation (LOQ) were 17.5 ng/mL and 55.0 ng/mL, respectively. The intra-day and inter-day precision of the method were 0.5-1.4 % and 0.7-1.8 % in relative standard deviation, respectively, while those accuracy were 99.5-100.9 % and 100.0- 102.2 %, respectively. The repeatability of oleanolic acid in samples ranged of 0.3-1.9 % based on peak area and 0.3-0.7 % for retention time. Recoveries from samples were 95.0-99.4 % with lower than 1.8 % in relative standard deviation. Overall, the developed analytical method will be used for quality control of this commercial scalp tonic products successfully.
Silver nanoparticles cause complications in pregnant mice
Zhang, Xi-Feng,Park, Jung-Hyun,Choi, Yun-Jung,Kang, Min-Hee,Gurunathan, Sangiliyandi,Kim, Jin-Hoi Dove Medical Press 2015 INTERNATIONAL JOURNAL OF NANOMEDICINE Vol.10 No.-
<P><B>Background</B></P><P>Silver nanoparticles (AgNPs) have attracted much interest and have been used for antibacterial, antifungal, anticancer, and antiangiogenic applications because of their unique properties. The increased usage of AgNPs leads to a potential hazard to human health. However, the potential effects of AgNPs on animal models are not clear. This study was designed to investigate the potential impact of AgNPs on pregnant mice.</P><P><B>Methods</B></P><P>The synthesis of AgNPs was performed using culture extracts of <I>Bacillus cereus</I>. The synthesized AgNPs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy. AgNPs were administrated into pregnant mice via intravenous infusion at 1.0 mg/kg doses at 6.5 days postcoitum (dpc). At 13.5, 15.5, and 17.5 dpc, the pregnant mice were euthanized, and the embryo and placenta were isolated. The meiotic status of oocytes was evaluated. DNA methylation studies were performed, and aberrant imprinting disrupted fetal, placental, and postnatal development. Quantitative real-time polymerase chain reaction analysis and Western blot were used to analyze various gene expressions.</P><P><B>Results</B></P><P>The synthesized AgNPs were uniformly distributed and were spherical in shape with an average size of 8 nm. AgNPs exposure increased the meiotic progression of female germ cells in the fetal mouse ovaries, and maternal AgNP exposure significantly disrupted imprinted gene expression in 15.5 dpc embryos and placentas, such as <I>Ascl2</I>, <I>Snrpn</I>, <I>Kcnq1ot1</I>, <I>Peg3</I>, <I>Zac1</I>, <I>H19</I>, <I>Igf2r</I>, and <I>Igf2</I>; DNA methylation studies revealed that AgNPs exposure significantly altered the methylation levels of differentially methylated regions of <I>Zac1</I>.</P><P><B>Conclusion</B></P><P>The results from this study indicated that early exposure to AgNPs has the potential to disrupt fetal and postnatal health through epigenetic changes in the embryo and abnormal development of the placenta. These results can contribute to research involved in the safe use of various biomedical applications of AgNPs and improves the understanding of the development of AgNPs in biomedical applications.</P>
Ying, Xi-Xiang,Li, Hai-Bo,Chu, Zheng-Yun,Zhai, Yan-Jun,Leng, Ai-Jing,Liu, Xun,Xin, Chun,Zhang, Wen-Jie,Kang, Ting-Guo 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.7
To investigate the antioxidant effect of vitexin-4"-O-glucoside, a flavone glycoside, isolated from the leaves of Crataegus pinnatifida Bge. var. major, we developed a simple and sensitive high-performance liquid chromatography (HPLC) method to determine levels of malondialdehyde (MDA) in ECV304 cell culture medium after induction by tert-butyl-hydroperoxide (TBHP). The preparation of analyzed samples involved a one-step derivatization with thiobarbituric acid (TBA). HPLC analysis was performed on a $Synergi^{TM}$ Hydro-RP, a polar end-capped $C_{18}$ column ($250{\times}4.6\;mm$, $4\;{\mu}m$), using an acetonitrile-ammonium acetate aqueous solution (10 mM, pH 6.8) as the mobile phase under linear gradient conditions with UV detection at 532 nm. The calibration curve was linear over $0.0125-1.25\;{\mu}M$ MDA (r=0.9951). Relative standard deviations (RSDs) of intra-day and inter-day precision were less than 6.1% and 5.0%, respectively. The mean recovery was $96.9\;{\pm}\;1.6%$. The lower limit of quantification (LLOQ) of MDA was $0.0125\;{\mu}M$. This chromatographic method was successfully applied to investigating the in vitro antioxidant effect of vitexin-4"-O-glucoside. Vitexin-4"-O-glucoside (120 M) protected ECV304 cells from peroxidation induced by TBHP.