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Imaging the Enzymatic Reaction of Urease Using Liquid Crystal-Based pH Sensor
Hu, Qiong-Zheng,Jang, Chang-Hyun Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.12
In this study, real-time and label-free methods for monitoring the enzymatic reaction of urease, which releases ammonia through the hydrolysis of urea in an aqueous solution, were developed using a liquid crystal (LC)-based pH sensor. Nematic liquid crystal 4-cyano-4'-pentylbiphenyl (5CB), doped with 4'-pentyl-biphenyl-4-carboxylic acid (PBA), exhibited a shift in optical appearance from bright to dark when it was in contact with ammonia generated from the enzymatic reaction between urease and urea. This optical change was attributed to the anchoring transitions of LCs caused by hydrophobic interactions between the tails of deprotonted PBA ($PBA^-$) molecules and the LCs at the aqueous/LC interface. This novel technique holds great promise for the sensitive detection of urease along with its substrates and inhibitors.
Imaging the Enzymatic Reaction of Urease Using Liquid Crystal-Based pH Sensor
장창현,Qiong-Zheng Hu 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.12
In this study, real-time and label-free methods for monitoring the enzymatic reaction of urease, which releases ammonia through the hydrolysis of urea in an aqueous solution, were developed using a liquid crystal (LC)-based pH sensor. Nematic liquid crystal 4-cyano-4'-pentylbiphenyl (5CB), doped with 4'-pentyl-biphenyl-4-carboxylic acid (PBA), exhibited a shift in optical appearance from bright to dark when it was in contact with ammonia generated from the enzymatic reaction between urease and urea. This optical change was attributed to the anchoring transitions of LCs caused by hydrophobic interactions between the tails of deprotonted PBA (PBA^−) molecules and the LCs at the aqueous/LC interface. This novel technique holds great promise for the sensitive detection of urease along with its substrates and inhibitors.
Dong Fang,Zheng Hu-Zhe,Jeong Woo-Sik,Chung Shin-Kyo,Qu Zhong-Yuan,Zou Xiang,Liu Chen,Xiang Qiong,Feng Feng 한국응용생명화학회 2021 Applied Biological Chemistry (Appl Biol Chem) Vol.64 No.S
In order to obtain and explore selenide composed of selenium and polysaccharide, three parameters were selected to optimize the synthesis process of selenium-Euryale ferox Salisb. polysaccharide (Se-ESPS) by Box-Behnken design. Furthermore, ESPS-B1 separated from ESPS was selenitized to Se-ESPS-B1 by the optimal synthesis process, then the characterization, and antioxidant activity in vitro of Se-ESPS-B1 were explored. The result manifested that the Se content of Se-ESPS was (2.915 ± 0.03) mg/g according to the optimal synthesis process of Se-ESPS (reaction time at 5 h, reaction temperature at 81 ℃, weight ratio of Na2SeO3 to ESPS at 0.9 g/g). A series of detection results indicated that the characterizations of Se-ESPS-B1 were apparently distinguished from that of ESPS-B1. Moreover, the antioxidant experiments in vitro demonstrated that Se-ESPS-B1 could exert antioxidant activity by scavenging DPPH, ABTS,·OH, and increasing reduction ability. In conclusion, the synthesis process is an effective approach to harvest seleniumpolysaccharide, and Se-ESPS-B1 may be utilized as a potential antioxidant or selenium nutritional supplement.
New Triterpenoids from the Fruits of Schisandra wilsoniana and Their Biological Activities
Gao, Xue-Mei,Li, Yun-Qi,Shu, Li-Dan,Shen, Yan-Qiong,Yang, Li-Ying,Yang, Liu-Meng,Zheng, Yong-Tang,Sun, Han-Dong,Xiao, Wei-Lie,Hu, Qiu-Fen Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.3
Investigation of an organic extract of the fruits Schisandra wilsoniana led to the isolation of two new highly oxygenated nortriterpenoids, named schilancidilactones V-W (1-2). Their structures were elucidated by spectroscopic evidence. Compounds 1-2 feature a double bond between C-7 and C-8 compared with related known nortriterpenoids isolated from the genus Schisandra. Compounds 1 and 2 were tested for their anti-HIV-1 activities and cytotoxicity. The results revealed that compounds 1 and 2 showed moderate anti-HIV-1 activities with $EC_{50}$ 3.05 and 2.87 ${\mu}g/mL$, respectively, and compound 1 showed high cytotoxicity against KB and MDA-MB-231 cell with $IC_{50}$ values of 3.18 and 5.22 ${\mu}M$, respectively.