- Determination of Catechol-O-Methyltransferase Activity in Various Tissues by Liquid Chromatography
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Catechol-O-methyltransferase activity was determined using liquid chromatography with amperometric detection.With dopamine as a substrate, the method allowed the individual determination of both posible product isomers in the various biological matrices investigated.The selectivity of the electrochemical detector proved advantageous in several aspects, including higher sample throughput, negligible blank values, and simplified chromatograms.The resolution of the reverse phase column permitted the incorporation of an internal standard, 3-methoxy-4-hydroxybenzylamine,to improve the precision to less than 4percent RSD for either the 3- or 4-O-methyl product isomers.The use of the product isomer preference ratios may be of clinical significance.
- Shoup, Ronald E.,Davis, Gregory C.,Kissinger, Peter T.
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- Structure–activity relationship and biological evaluation of berberine derivatives as PCSK9 down-regulating agents
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Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a secreted protein and its deficiency markedly enhanced the survival rate of patient with cardiovascular diseases (CVDs). Forty berberine (BBR) derivatives were synthesized and evaluated for their activities on down-regulating the transcription of PCSK9 in HepG2 cells, taking BBR as the lead. Structure–activity relationship (SAR) analysis revealed that 2,3-dimethoxy moiety might be beneficial for activity. Among them, 9k displayed the most potent activity with IC50 value of 9.5 ± 0.5 μM, better than that of BBR. Also, it significantly decreased PCSK9 protein level at cellular level, as well as in the liver and serum of mice in vivo. Furthermore, 9k markedly increased LDLR expression and LDL-C clearance via down-regulating PCSK9 protein. The mechanism of action of 9k is targeting HNF1α and/or Sp1 cluster modulation upstream of PCSK9, a different one from BBR. Therefore, 9k might have the potential to be a novel PCSK9 transcriptional inhibitor for the treatment of atherosclerosis, worthy for further investigation.
- Fan, Tian-Yun,Yang, Yu-Xin,Zeng, Qing-Xuan,Wang, Xue-Lei,Wei, Wei,Guo, Xi-Xi,Zhao, Li-Ping,Song, Dan-Qing,Wang, Yan-Xiang,Wang, Li,Hong, Bin
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- Organocatalytic enantioselective pictet-spengler reactions for the syntheses of 1-substituted 1,2,3,4-tetrahydroisoquinolines
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A series of 1-substituted 1,2,3,4-tetrahydroisoquinolines was prepared from N-(o-nitrophenylsulfenyl)phenylethylamines through BINOL-phosphoric acid [(R)-TRIP]-catalyzed asymmetric Pictet-Spengler reactions. The sulfenamide moiety is crucial for the rate
- Mons, Elma,Wanner, Martin J.,Ingemann, Steen,Van Maarseveen, Jan H.,Hiemstra, Henk
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p. 7380 - 7390
(2014/09/17)
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- Drug metabolism-based design, synthesis, and bioactivities of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)propane hydrochloride (DDPH) analogs as α1-adrenoceptors antagonists
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1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)propane hydrochloride (DDPH) is a potent α1-adrenoceptor antagonist that is currently under Phase II clinic trials. However, the fast metabolism has restricted its further use. In this paper, 11 DDPH analogs were designed according to the probable metabolism pathways of DDPH, and featured the structures of halogen, methyl, and cyano groups at the 3-, or 4-position of aromatic ring A to block the hydroxylation, and one hydroxyl group at the 3-, or 4-position of aromatic ring B to extend the duration time. These compounds were synthesized in moderate to good yields from the reductive amination of substituted phenoxyacetones with substituted phenylethylamines, and fully characterized with 1H NMR, IR, and HRMS. Biological evaluation indicated that most of the compounds exhibited strong blocking and moderate to good antihypertensive activities. It is clear that the compounds having 4-OH/3-OMe on group B exhibited higher blocking activities and longer duration time than their corresponding analogs having 4-OMe/3-OMe (and also 3-OH/4-OMe). Among them, compound 13 having bromo group at the 4-position of ring A and 4-OH/3-OMe on group B, exhibited the highest blocking activity, whereas compound 17 that had a methyl group at the 4-position of ring A and a hydroxyl group at the 4-position of ring B, was more active than potent DDPH in terms of both blocking and antihypertensive activities. In addition, the possible correlations between the blocking and antihypertensive activities are also briefly discussed.
- Xi, Bao-Min,Jiang, Zhen-Zhou,Zou, Jian-Wei,Ni, Pei-Zhou,Chen, Wen-Hua
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p. 783 - 788
(2011/03/19)
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- Tetrahydroisoquinoline based sulfonamide hydroxamates as potent matrix metalloproteinase inhibitors
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The synthesis and MMP inhibitory activity of a series of tetrahydroisoquinoline based sulfonamide hydroxamates are described. In nine MMPs tested, most of the compounds display potent inhibition activity except for MMP-7. Some subtle isozyme selectivity is observed by varying the substituents at the 6- and 7-positions and aromatic ring of arylsulfonyl groups.
- Ma, Dawei,Wu, Wengen,Yang, Guoxin,Li, Jingya,Li, Jia,Ye, Qizhuang
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- SYNTHESES BASED ON β-PHENYLETHYLAMINES. I. PREPARATION OF SUBSTITUTED β-PHENYLETHYLAMINES
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A comparative study has been made of methods of synthesizing substituted β-phenylethylamines via the corresponding nitriles and via nitrostyrenes, and a superiority of the latter method has been established.The possibility has been shown for the first time of reducing nitrostyrenes to saturated amines with diisobutylaluminum hydride (DIBAH).The use of DIBAH as reducing agent enables amines to be obtained in high yields.
- Vinogradova, V. I.,Yunusov, M. S.,Kuchin, A. V.,Tolstikov, G. A.,Sagandykov, R. T.,et al.
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