- Structure-activity relationship studies of (E)-3,4-dihydroxystyryl alkyl sulfones as novel neuroprotective agents based on improved antioxidant, anti-inflammatory activities and BBB permeability
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(E)-3,4-dihydroxystyryl alkyl sulfones, as new analogues of neurodegenerative agents, were designed and synthesized. The biological results demonstrated that most of the target compounds preserved antioxidant and anti-inflammatory potency in scavenging reactive free radicals, protecting neuronal cells against neurotoxins such as H2O2, 6-hydroxydopamine and inhibiting lipopolysaccharide (LPS)-induced over-production of NO. Among these compounds, 6.22 with cyclopentyl propyl exhibited prominent antioxidant activity at low concentration (2.5 μM) in H2O2 model (cell viability = 94.5%). In addition, 6.22 (IC50 = 1.6 μM) displayed better anti-inflammatory activity than that of lead compound 1 (IC50 = 13.4 μM). In view of the outstanding performance of 6.22, the apoptotic rates of H2O2-damaged PC12 cells were detected by Annexin V-FITC/PI assay. 6.22 showed higher potency in inhibition of apoptosis than 1 at low concentration (2.5 μM), consisting with the antioxidant and anti-inflammatory models. Furthermore, with the predicted CNS (+) blood-brain barrier (BBB) permeability (Pe = 6.84 × 10?6 cm s?1), low cytotoxicity and favorable physiochemical properties based on calculation, compound 6.22 can be further developed as a potential multifunctional neuroprotective agent.
- Chen, Ying,Wu, Bolin,Hao, Yameng,Liu, Yunqi,Zhang, Zhili,Tian, Chao,Ning, Xianling,Guo, Ying,Liu, Junyi,Wang, Xiaowei
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p. 420 - 433
(2019/03/29)
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- Preparation method of bromomethylcyclohexane
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The invention relates to a preparation method of bromomethylcyclohexane. The method comprises the steps that 1, alkali and cyclohexylmethanol are added into an organic solvent, then a compound in theformula (I) shown in the description is added dropwise, and esterification is conducted to obtain an organic-phase intermediate filtrate, wherein R is C1-12 alkyl or C1-12 halogen alkyl or C3-8 naphthenic base or phenyl or benzyl or aromatic hydrocarbon, X is a halogen atom, and the molar radio of the cyclohexylmethanol to the compound in the formula (I) is 1:1-1:2; 2, a bromide and a crown ethercatalyst are added into the obtained organic-phase intermediate filtrate for bromination reaction to obtain reaction liquid, then through filtering, abraum salt is removed, through rectification, a crude bromomethylcyclohexane product is obtained, and then through drying, a finished bromomethylcyclohexane product is obtained. The method has the advantages that high-salinity wastewater is reduced,reaction time is shortened, the reaction rate is improved, the production cost is reduced, and the product yield is improved.
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Paragraph 0010-0013
(2018/03/26)
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- SYNTHESIS METHOD FOR L-CYCLIC ALKYL AMINO ACID AND PHARMACEUTICAL COMPOSITION HAVING THEREOF
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A synthesis method for L-cyclic alkyl amino acid and a pharmaceutical composition having the said amino acid are provide in the present disclosure provides. The synthesis method comprises: step A.) preparing a cyclic alkyl keto acid or a cyclic alkyl keto acid salt having Structural Formula (I) or Structural Formula (II), and step B.) mixing the cyclic alkyl keto acid or the cyclic alkyl keto acid salt with ammonium formate, a leucine dehydrogenase, a formate dehydrogenase and a coenzyme NAD+, and carrying out a reductive amination reaction to generate the L-cyclic alkyl amino acid, wherein the Structural Formula (I) is where n1≧1, m1≧0 and the M1 is H or a monovalent cation; the Structural Formula (II) is where n2≧0, m2≧0, the M2 is H or a monovalent cation, an amino acid sequence of the leucine dehydrogenase is SEQ ID No.1.
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- Homolytic Ring Fission reactions of Bicycloalkanes and Bicycloalk-2-yl Radicals: Electron Spin Resonance Study of Cycloalkenylmethyl Radicals
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Hydrogen abstraction from bicycloalkanes (n=3-6) by t-butoxyl radicals was examined by an e.s.r. technique.The main site of attack was C(2) giving bicycloalk-2-yl radicals which rearranged by β-scission of the outer cyclopropane bonds to give cycloalkenylmethyl radicals.This is in contrast to the bicycloalk-2-yl radicals (n=1,2) which rearranged by fission of the inter-ring bonds to give cycloalkenyl radicals. β-Scission in bicycloalk-2-yl radicals was examined by semi-empirical SCF MO calculations.The conformations and barriers to internal rotation of the cycloalkenylmethyl radicals were determined from the variation in the β-H hyperfine splitting constants with temperature.Photobromination of bicycloalkanes (n=3,4) was also investigated in CCl4 solution.The main process was bimolecular homolytic substitution (SH2) by bromine atoms at the cyclopropane carbons, but there was an increase in hydrogen abstraction with ring size.The SH2 reactions parallel the β-scission reactions of the bicycloalk-2-yl radicals in that the main bond undergoing fission changes from the inter-ring bond to the outer cyclopropane bond as the ring size increases.
- Roberts, Charles,Walton, John C.
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p. 879 - 886
(2007/10/02)
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- Photochemistry of Alkyl Halides. 9. Geminal Dihalides
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The photobehavior of the geminal dihalides (diiodomethyl)cyclohexane (7), (bromoiodomethyl)cyclohexane (11), (dibromomethyl)cyclohexane (17), (diiodomethyl)cyclopentane (22), 3,3-dimethyl(diiodomethyl)cyclobutane (27), and 8,8-diiodo-2,6-dimethyl-2-octene (31) has been studied and compared with that previously observed for diiodomethane.In all solvents the corresponding vinyl halides (iodomethylene)cyclohexane (13), (bromomethylene)cyclohexane (21), (iodomethylene)cyclopentane (23), 3,3-dimethyl(iodomethylene)cyclobutane (28), or cis- and trans-3,7-dimethyl-1-iodo-1,6-octadiene (33) were obtained, which are thought to arise from α-halo cationic intermediate formed via initial light-induced homolytic cleavage of the carbon-iodine bond followed by electron transfer within the resulting caged radical pair, as shown in Schemes II and III.In the case of diiodide 31 competing intramolecular trapping of the α-iodo cation afforded in addition the cyclized isopulegyl iodide (34).In polar solvents the vinyl iodides were accompanied by the nonhalogenated products methylenecyclohexane (15), 1-methylcyclopentene (25), cyclohexene (26), 4,4-dimethylcyclopentene (29), and cis- and trans-carane (35), which are thought also to arise from the α-halo cationic intermediate. 1.1-Diiodo-2,2-dimethylpropane (1b) afforded 2-methyl-2-butene (6b).Except for carane (35) from diiodide 31 there was no detectable formation of cyclopropanes.In methanol the nucleophilic substitution products (dimethoxymethyl)cyclohexane (14), (dimethoxymethyl)cyclopentane (24), and 1,1-dimethoxy-2,2-dimethylpropane (30) were obtained.It is concluded that geminal dihalides undergo predominant, if not exclusive, photoreaction via initial clea vage of a single carbon-halogen bond in analogy with monohalides and that carbene intermediates are not formed.A similiar conclusion has been reached previously for diiodomethane in the photocyclopropanation of alkenes.
- Kropp, Paul J.,Pienta, Norbert J.
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p. 2084 - 2090
(2007/10/02)
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- The Conformations of Cycloalkylmethyl Radicals and Barriers to Internal Rotation
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Cycloalkylmethyl radicals with C4, C5, C6, C8, and C11 rings have been studied by e.s.r. spectroscopy.The preferred conformation for cyclobutylmethyl and cyclopentylmethyl radicals is the bisected form with Hβ in the nodal plane of the semi-occupied orbital; the radicals with larger rings adopt the eclipsed conformation.It is suggested that the conformational preferences of the radicals are governed by steric factors, except for cyclobutylmethyl where the bisected conformation is favoured by C-C hyperconjugation involving C. and the two Cα-Cβ bonds.The cycloundecylmethyl radical exists in two different conformations at low temperatures but at T > 230 K interconversion is fast and a single e.s.r. spectrum is observed.The barriers to internal rotation in the cycloalkylmethyl radicals were calculated from the temperature dependence of the β-hyperfine splitting using the classical limit procedure.The internal rotation about the C.-Cα bond was also studied by the MNDO and INDO semi-empirical SCF MO methods.
- Kemball, Mary L.,Walton, John C.,Ingold, Keith U.
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p. 1017 - 1024
(2007/10/02)
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- Silanes in Organic Synthesis. 10. Cleavage Reactions of Silylcyclopropanes with Titanium Tetrachloride and Hydrogen Chloride
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Seven trimethylsilyl-substituted cyclopropanes, both mono- and bicyclic, were treated with titanium tetrachloride and anhydrous hydrogen chloride to determine the regioselectivity and stereoselectivity of electrophilic attack on their strained three-membered ring.Whereas cleavage of exo-6-(trimethylsilyl)bicyclohexane with TiCl4 occurs predominantly at the zero bridge, the principal product obtained from treatment with HCl is the result of peripheral bond scission.In the case of exo-7-(trimethylsilyl)bicycloheptane, addition to an edge bond occurs regiospecifically with both reagents.Substrates 11 and 12 were examined to assess the importance of carbonium ion intervention.Structural isomerizations mediated by such intermediates were observed with both silylcyclopropanes.For 1-(trimethylsilyl)bicycloheptane and 1-(trimethylsilyl)-1-pentylcyclopropane, the altered position of the silicon substituent was seen to have a major effect on the course of ring opening.Although the present data allow some analogies to be drawn with vinylsilanes, it is clear that silylcyclopropanes have a broader range of reaction pathways available to them than do their olefinic counterparts.
- Daniels, Rhys G.,Paquette, Leo A.
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p. 2901 - 2910
(2007/10/02)
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- 1-[2-(1-Adamantyl)-2-(R-thio)ethyl]imidazoles and 1-[2-(1-adamantyl)-2-(R-oxy)ethyl]imidazoles
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Compounds of the formula STR1 wherein R is alkyl, cycloalkyl, cycloalkyl lower alkyl, phenyl or phenyl lower alkyl, said phenyl and phenyl lower alkyl optionally substituted on the phenyl ring with one or more substituents independently selected from the group consisting of halo, lower alkyl and trifluoromethyl; and X is oxygen or sulfur with the proviso that X is not oxygen when R is phenyl or substituted phenyl; and the antimicrobial acid addition salts thereof are useful as antifungal, antibacterial and antiprotozoal agents.
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