- Discovery and Development of Small-Molecule Inhibitors of Glycogen Synthase
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The overaccumulation of glycogen appears as a hallmark in various glycogen storage diseases (GSDs), including Pompe, Cori, Andersen, and Lafora disease. Accumulating evidence suggests that suppression of glycogen accumulation represents a potential therapeutic approach for treating these GSDs. Using a fluorescence polarization assay designed to screen for inhibitors of the key glycogen synthetic enzyme, glycogen synthase (GS), we identified a substituted imidazole, (rac)-2-methoxy-4-(1-(2-(1-methylpyrrolidin-2-yl)ethyl)-4-phenyl-1H-imidazol-5-yl)phenol (H23), as a first-in-class inhibitor for yeast GS 2 (yGsy2p). Data from X-ray crystallography at 2.85 ?, as well as kinetic data, revealed that H23 bound within the uridine diphosphate glucose binding pocket of yGsy2p. The high conservation of residues between human and yeast GS in direct contact with H23 informed the development of around 500 H23 analogs. These analogs produced a structure-activity relationship profile that led to the identification of a substituted pyrazole, 4-(4-(4-hydroxyphenyl)-3-(trifluoromethyl)-1H-pyrazol-5-yl)pyrogallol, with a 300-fold improved potency against human GS. These substituted pyrazoles possess a promising scaffold for drug development efforts targeting GS activity in GSDs associated with excess glycogen accumulation.
- Tang, Buyun,Frasinyuk, Mykhaylo S.,Chikwana, Vimbai M.,Mahalingan, Krishna K.,Morgan, Cynthia A.,Segvich, Dyann M.,Bondarenko, Svitlana P.,Mrug, Galyna P.,Wyrebek, Przemyslaw,Watt, David S.,Depaoli-Roach, Anna A.,Roach, Peter J.,Hurley, Thomas D.
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p. 3538 - 3551
(2020/04/30)
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- Enzymatic studies of isoflavonoids as selective and potent inhibitors of human leukocyte 5-lipo-oxygenase
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Continuing our search to find more potent and selective 5-LOX inhibitors, we present now the enzymatic evaluation of seventeen isoflavones (IR) and nine isoflavans (HIR), and their in vitro and in cellulo potency against human leukocyte 5-LOX. Of the 26 compounds tested, 10 isoflavones and 9 isoflavans possessed micromolar potency, but only three were selective against 5-LOX (IR-2, HIR-303, and HIR-309), with IC50 values at least 10 times lower than those of 12-LOX, 15-LOX-1, and 15-LOX-2. Of these three, IR-2 (6,7-dihydroxy-4-methoxy-isoflavone, known as texasin) was the most selective 5-LOX inhibitor, with over 80-fold potency difference compared with other isozymes; Steered Molecular Dynamics (SMD) studies supported these findings. The presence of the catechol group on ring A (6,7-dihydroxy versus 7,8-dihydroxy) correlated with their biological activity, but the reduction of ring C, converting the isoflavones to isoflavans, and the substituent positions on ring B did not affect their potency against 5-LOX. Two of the most potent/selective inhibitors (HIR-303 and HIR-309) were reductive inhibitors and were potent against 5-LOX in human whole blood, indicating that isoflavans can be potent and selective inhibitors against human leukocyte 5-LOX in vitro and in cellulo. Of the 26 compounds tested, 10 isoflavones and 9 isoflavans possessed micromolar potency, but only three were selective against 5-LOX (IR-2, HIR-303, and HIR-309), with IC50 values at least 10 times lower than those of 12-LOX, 15-LOX-1, and 15-LOX-2. Docking and steered molecular dynamics were performed to determinate the structure-activity relationship.
- Mascayano, Carolina,Espinosa, Victoria,Sepúlveda-Boza, Silvia,Hoobler, Eric K.,Perry, Steve,Diaz, Giovanni,Holman, Theodore R.
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p. 894 - 901
(2015/06/23)
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- Development of 3-alkyl-6-methoxy-7-hydroxy-chromones (AMHCs) from natural isoflavones, a new class of fluorescent scaffolds for biological imaging
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Starting from 7-hydroxyisoflavones, we developed a new class of fluorescent scaffolds, 3-alkyl-6-methoxy-7-hydroxy-chromones (AMHCs, MW ~ 205.19, λab ~ 350 nm, λem ~ 450 nm) via a trial and error process. AMHCs have the advantages of being a small molecular moiety, having strong fluorescence in basic buffers, reasonable solubility and stability, non-toxicity, and are conveniently linked to pharmacophores. AMHCs were successfully used in fluorescence microscopy imaging of cells and tissues. This journal is
- Miao, Jianzhuang,Cui, Huaqing,Jin, Jing,Lai, Fangfang,Wen, Hui,Zhang, Xiang,Ruda, Gian Filippo,Chen, Xiaoguang,Yin, Dali
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supporting information
p. 881 - 884
(2015/02/19)
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- Synthesis and biological studies of 4′, 7, 8-trihydroxy-isoflavone metal complexes
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A new series of complexes of a ligand 4′, 7, 8-trihydroxy-isoflavone with transition metal (zinc, copper, manganese, nickel, cobalt) and selenium have been synthesized and characterized with the aid of elemental analysis, IR, electron ionization mass spectrum (EI-MS) and 1H NMR spectrometric techniques. The compounds were evaluated for their in vitro antibacterial activities and antitumor properties. The metal complexes were found to be more active than the free ligand. Investigation on the interaction between the complexes and calf-thymus DNA (CT DNA) showed that the absorbance of CT DNA increased and the maximum peak (λmax = 260 nm) red-shifted, while the intensity of fluorescence spectra of Epstein-Bart DNA (EB-DNA) gradually weakened, which indicated that all of these metal complexes tightly combined with CT DNA.
- Tang, Li-Jun,Chen, Xiang,Sun, Yu-Na,Ye, Jia,Lu, Jing,Han, Ying,Jiang, Xing,Cheng, Chan-Chan,He, Cheng-Cheng,Qiu, Pei-Hong,Li, Xiao-Kun
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experimental part
p. 1623 - 1629
(2012/05/19)
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- The synthesis, structure and activity evaluation of pyrogallol and catechol derivatives as Helicobacter pylori urease inhibitors
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Some pyrogallol and catechol derivatives were synthesized, and their urease inhibitory activity was evaluated by using acetohydroxamic acid (AHA), a well known Helicobacter pylori urease inhibitor, as positive control. The assay results indicate that many compounds have showed potential inhibitory activity against H. pylori urease. 4-(4-Hydroxyphenethyl)phen-1,2-diol (2a) was found to be the most potent urease inhibitor with IC50s of 1.5 ± 0.2 μM for extracted fraction and 4.2 ± 0.3 μM for intact cell, at least 10 times and 20 times lower than those of AHA (IC50 of 17.2 ± 0.9 μM, 100.6 ± 13 μM), respectively. This finding indicate that 2a would be a potential urease inhibitor deserves further research. Molecular dockings of 2a into H. pylori urease active site were performed for understanding the good activity observed.
- Xiao, Zhu-Ping,Ma, Tao-Wu,Fu, Wei-Chang,Peng, Xiao-Chun,Zhang, Ai-Hua,Zhu, Hai-Liang
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experimental part
p. 5064 - 5070
(2010/12/24)
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- Synthesis and structure-activity relationship study of deoxybenzoins on relaxing effects of porcine coronary artery
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Deoxybenzoins are potent antioxidants and tyrosinase inhibitors with potential to be developed as food preservatives and cosmetic ingredients. To explore the potential in cardiovascular protection, 25 polyphenolic deoxybenzoins were synthesized and evaluated for inhibitory effects on KCl-induced porcine coronary arterial contraction. The results revealed deoxybenzoins are significant inhibitors of KCl-induced arterial contraction. Among those synthesized, two-thirds of the deoxybenzoins exhibited moderate to good efficacy on relaxing contracted artery including 2,4-dihydroxydeoxybenzoin with EC50 = 3.30 μM (Emax = 100%, n = 7) and 2,4-dihydroxy-4′-methoxydeoxybenzoin EC50 = 3.70 μM (E max = 100%, n = 5). Deoxybenzoins displayed an endothelium-dependent relaxing manner on the contracted artery; the contractile responses of neither endothelium denuded nor L-NAME deactivated rings were inhibited. The structure-activity relationships of deoxybenzoin on arterial relaxing effects concluded that the 2,4-dihydroxylated deoxybenzoins presented a potential vascular relaxing pharmacophore, with favoring substitution on ring B in the order of H ≤ p-OMe > p-OH > o-OMe > m,p-diOMe ≤ m-OMe.
- Lu, Tzy-Ming,Kuo, Daih-Huang,Ko, Horng-Huey,Ng, Lean-Teik
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experimental part
p. 10027 - 10032
(2011/05/17)
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- Potential antioxidants and tyrosinase inhibitors from synthetic polyphenolic deoxybenzoins
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Deoxybenzoins (DOBs) are one-pot synthetic precursors of isoflavones with feature analogous to those beneficial polyphenols such as resveratrol (stilbene) and phloretin (dihydrochalcone). In this study, seventeen polyphenolic DOBs were synthesized and evaluated by various antioxidant assays and tyrosinase inhibitory effect in vitro. Results displayed that these DOBs are powerful antioxidants; for example, 2,3,4-trihydroxy-3′,4′-dimethoxydeoxybenzoin possesses an excellent anti-lipid peroxidation activity (IC50 = 0.72 ± 0.16 μM), whilst 2,4,4′,5-tetrahydroxydeoxybenzoin showed good DPPH radical scavenging activity (IC50 = 0.69 ± 0.04 μM), which were better than Trolox and vitamin C. Besides exhibiting a weak metal chelating effect, these DOBs were effective in scavenging ABTS{radical dot}+ and superoxide anion (O2{radical dot} -) radicals. DOBs also exhibited potent mushroom tyrosinase inhibitory activity; for example 2,3,4′-trihydroxy-4-methoxydeoxybenzoin displayed stable and significant inhibitory effect on tyrosinase activity, with IC50 values 43.37, 43.10 and 46.10 μM at incubation intervals of 0.5, 1.5, and 2.5 h, respectively. These results suggest that, with the advantage of being readily synthesizable small molecules, DOBs can be potentially developed into clinical and industrial antioxidants. Crown Copyright
- Ng, Lean-Teik,Ko, Horng-Huey,Lu, Tzy-Ming
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experimental part
p. 4360 - 4366
(2009/10/17)
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- Polyphenols based on isoflavones as inhibitors of Helicobacter pylori urease
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Twenty polyphenols were synthesized and evaluated for their effect on Helicobacter pylori urease. Among these compounds, 4-(p-hydroxyphenethyl)pyrogallol (15) (IC50 = 0.03 mM) and 7,8,4′-trihydroxyisoflavone (19) (IC50 = 0.14 mM) showed potent inhibitory activities, and inhibited Helicobacter pylori urease in a time-dependent manner. The structure-activity relationship of these polyphenols revealed: the two ortho hydroxyl groups were essential for inhibitory activity of polyphenol. When the C-ring of isoflavone was broken, the inhibitory activity markedly decreased. As for deoxybenzoin, the carboxyl group was clearly detrimental.
- Xiao, Zhu-Ping,Shi, Da-Hua,Li, Huan-Qiu,Zhang, Li-Na,Xu, Chen,Zhu, Hai-Liang
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p. 3703 - 3710
(2008/02/07)
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- Expedient Synthesis of Polyhydroxyisoflavones
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A general and direct synthesis of polyhydroxy isoflavones (3-phenyl-4H-1-benzopyran-4-ones) starting from the corresponding unprotected phenols and arylacetic acids is described.The aryl rings may carry additional alkyl, methoxy and/or halogeno groups.Intermediate polyhydroxydeoxybenzoins (1,2-diphenylethanones) can also be isolated in good yields.
- Waehaelae, Kristiina,Hase, Tapio A.
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p. 3005 - 3008
(2007/10/02)
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