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Jin, Feng,Jin, Xing Yu,Jin, Ying Lan,Sohn, Dae-Won,Kim, Soon-Ai,Sohn, Dong-Hwan,Kim, Youn-Chul,Kim, Hak-Sung 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.11
Butein, a natural chalcone, has anti-inflammatory and hepatoprotective activity. One synthetic derivative of butein, 2',4',6'-tris(methoxymethoxy)chalcone (TMMC), has potent anti-inflammatory activity via an HO-1 (heme oxygenase 1) dependent pathway. The ${\alpha},{\beta}-unsaturated$ ketone moiety in both TMMC and chalcones could be important in mediating this effect. To investigate the structural requirements of TMMC derivatives for anti-inflammatory effects, we modified the ${\alpha},{\beta}-unsaturated$ ketone moiety through catalytic hydrogenation, hydride reduction, or introduction of a triple bond. In addition, we performed structural modifications such as converting the -OMOM group to an -OMe or -OH group. Generally, modifications in the a,_-unsaturated ketone caused a significant decrease or loss of anti-inflammatory activity, which is consistent with the role of the a,_-unsaturated ketone group acting as a Michael acceptor of nucleophilic species like glutathione or cysteine residues on proteins. Chemically, the electron-donating substituents could make the thiol-adduct more stable by decreasing the acidity of the ${\alpha}-hydrogen$ and slowing the speed of the retro-Michael reaction. Also, like previous studies, the 2'-hydroxy group was crucial in increasing the anti-inflammatory effect. The 2'-hydroxy group produced potent anti-inflammatory effects by increasing the electrophilic properties of ${\alpha},{\beta}-unsaturated$ ketones due to hydrogen bonding between the 2'-hydroxy group and the ketone moiety.
A new macro-micro dual drive parallel robot for chromosome dissection
Jin Feng,Feng Gao,Xianchao Zhao,Yi Yue,Renqiang Liu 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.1
This paper presents a parallel-structure system dually driven by six servo motors and six piezoelectric actuators. Due to the combination of macro and micro manipulators which are both of orthogonal structures, the proposed system possesses a concise structure as well as actuation isolation and output motion decoupling properties. By using a glass needle mounted on a six-dimensional force sensor in endpoint operating, this system can be applied to chromosome dissection that to make the whole process more efficient and automatic. The glass needle tip has a stroke of 106 mm in three linear motions and 18.7-arc-degrees in three angle motion directions, with servo motors adopted. It also has the resolution of 20 nanometers with the adoption of piezoelectric actuators. The kinematics, isotropy, decoupling and design considerations of the proposed robot are discussed. Workspace and resolution of both macro and micro manipulators are measured separately. The experiments are also conducted to show its capability in dissecting chromosomes.
Feng-Xue Jin,Xiao-Bo Xie,Shi-Dong Ji,Hong-Guang Ju,Jung-Pil Suh,Hung-Goo Hwang,Sang-Nag Ahn 한국작물학회 2008 한국작물학회 학술발표대회 논문집 Vol.2008 No.10
Grain weight (GW) or grain size is the most important target not only as a major component of grain yield, but also associated with the cooking quality in rice breeding program. In a previous study, two loci for grain weight, gw8 and gw9, have been fine map to about 306.4kb and 37.4kb, respectively, in backcross populations derived from a cross between the Korean japonica cultivar Hwaseongbyeo and Oryza rufipigon (IRGC 105491). Both O.rufipogon alleles increased GW in the Hwaseongbyeo background despite the fact that O. rufipogon was the small-seeded parent. To test the effect of pyramiding the QTLs for grain weight, an F2 population consisted of 226 individuals was developed derived from the cross between the two QTLs (gw8 and gw9), and used MAS to select nearly isgenic lines for two QTLs and a pyramiding line. Molecular genotyping of F2 population revealed the existence of interaction between gw8 and gw9. Moreover, the interaction was also confirmed by phenotypic analysis of four QTL-NILs. The results suggest that epistasis interaction is important genetic basis in determining yield traits in rice.
Feng Jin,Xing Yu Jin,Ying Lan Jin,Dae Won Sohn,김순애,손동환,Youn Chul Kim,Hak Sung Kim 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.11
Butein, a natural chalcone, has anti-inflammatory and hepatoprotective activity. One synthetic derivative of butein, 2',4',6'-tris(methoxymethoxy)chalcone (TMMC), has potent anti-inflammatory activity via an HO-1 (heme oxygenase 1) dependent pathway. The α,β-unsaturated ketone moiety in both TMMC and chalcones could be important in mediating this effect. To investigate the structural requirements of TMMC derivatives for anti-inflammatory effects, we modified the α,β-unsaturated ketone moiety through catalytic hydrogenation, hydride reduction, or introduction of a triple bond. In addition, we performed structural modifications such as converting the -OMOM group to an -OMe or -OH group. Generally, modifications in the α,β-unsaturated ketone caused a significant decrease or loss of anti-inflammatory activity, which is consistent with the role of the α,β-unsaturated ketone group acting as a Michael acceptor of nucleophilic species like glutathione or cysteine residues on proteins. Chemically, the electron-donating substituents could make the thiol-adduct more stable by decreasing the acidity of the α-hydrogen and slowing the speed of the retro-Michael reaction. Also, like previous studies, the 2'- hydroxy group was crucial in increasing the anti-inflammatory effect. The 2'-hydroxy group produced potent anti-inflammatory effects by increasing the electrophilic properties of α,β-unsaturated ketones due to hydrogen bonding between the 2'-hydroxy group and the ketone moiety.
Jin, Ying Lan,Jin, Xing Yu,Jin, Feng,Sohn, Dong-Hwan,Kim, Hak-Sung 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.9
We previously synthesized 2', 4', 6'-tris(methoxymethoxy)chalcone (TMMC) derivatives with various substituents on the A ring that showed potent anti-inflammatory effects by inhibiting NO production in RAW 264.7 cells. The 2'-hydroxy group on the A ring could elevate the electrophilicity of Michael addition of GSH and electron donating groups on the A ring could stabilize the GSH adduct by decreasing the acidity of the $\alpha$-hydrogen. Using this interpretation, we tested various substituents on the B ring and established a proper balance between biological activity and the position of the electron donating or electron withdrawing groups on the B ring. In this case, the 2'-hydroxy group was excluded because it could cause the formation of GSSG through a phenoxy radical and can confuse the interpretation of the biological results. Chalcone derivatives without 2'-hydroxy are likely to deplete cellular GSH levels by a Michael addition process. Strong electron donating groups on the B ring, such as 4-dimethylamino group, gave the weakest inhibition of NO production. A 4-dimethyamino group on the B ring could decrease the stability of the GSH adduct by weakening the C-S bond strength through movement of an electron pair on nitrogen via an aromatic ring.
Relationship between Chemical Structures and Functions of Tea Polysaccharides
Feng Jin,Ling-Yan Jia,You-Ying Tu 한국차학회 2015 한국차학회지 Vol.- No.S
The worldwide consumption of tea is second only to water. Thus any health effects of drinking tea could have a significant impact on public health. Although tea has historically been thought to promote good health, research into the possible health benefits of tea is more recent. Tea polysaccharides sources show various important biological activities together with proteins and polynucleotides, such as anti-blood coagulation, anti-radiation, antioxidant, reducing blood sugar levels, hypoglycemic activities, anti-HIV, anti-cancer, cell-cell communication, cell adhesion and molecular recognition in the immune system, which are strongly affected by their chemical structures and chain conformations. In recent years, some tea polysaccharides sources have attracted much attention in the field of biochemistry and pharmacology. Observational studies have repeatedly shown that tea polysaccharides were mostly glycoconjugates in which a protein carries one or more carbohydrate chains covalently associated with a polypeptide backbone, usually some forms of via N- or O-linkages. It is interesting and important to elucidate the relation among chemical structures, chain conformations of tea polysaccharides and their biological activities. However, tea polysaccharides are usually composed of various monosaccharides linked with different glucosidic bonds. Some tea polysaccharides have hyperbranched structures. Moreover, tea polysaccharides often have high molecular weights, and tend to form aggregates in solution that can mask the behavior of individual macromolecules. In consequence, to characterize the chemical structures and chain conformations of polysaccharides is not an easy task. To make clear the chemical structures and chain conformations of tea polysaccharides is important to understand their biological activities. This article attempts to review the current development on structural and conformational characterization of some tea polysaccharides. In this paper, the various aspects of the investigation results of tea polysaccharides chemical structures in the recent decades were summarized. The chemical structures were analyzed by FTIR, NMR (one and two dimensions), CD and AFM, and so on.