Antioxidants have been considered as potential antiatherogenic agents by inhibiting oxidation of low-density lipoprotein (LDL), albeit vitamin E, a natural antioxidant, has failed to show reduction on atherosclerosis in clinical trials. We have rationally designed and synthesized a novel series of antioxidants, 4,6-di-tert-butyl-2,3-dihydro-5-benzofuranols, to overcome the clinical limitation of vitamin E. In vitro, the compounds showed a potent inhibitory effect on lipid peroxidation detected as 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin3-one (MCLA)-dependent chemiluminescence in linoleic acid autoxidation. They also inhibited the LDL oxidation induced by Cu2+, and the inhibition is more potent than that of vitamin E and probucol. In vivo, 4,6-di-tert-butyl-2,3-dihydro-2,2-dipentyl-5-benzofuranoI (BO-653, 1f), an optimal compound, showed the highest concentration in plasma and LDL fraction in Watanabe heritable hyperlipidemic rabbits, due to its high affinity to LDL. The isolated LDL samples from the If-treated rabbits showed potent resistibility to LDL oxidation. Compound If has been taken into clinical trials.
Synthesis and biological evaluation of galactofuranosyl alkyl thioglycosides as inhibitors of mycobacteria
作者:Chris B. Davis、Regan D. Hartnell、Paul D. Madge、David J. Owen、Robin J. Thomson、Andrew K.J. Chong、Ross L. Coppel、Mark von Itzstein
DOI:10.1016/j.carres.2007.04.027
日期:2007.9
As part of our research interest directed toward the development of antimycobacterial agents, we have investigated compounds based on galactofuranose (Galf), an essential cell wall component of mycobacteria. The objective of this study was to explore structure activity relationships of Galf thioglycosides with straight chain and branched aglycons. Acylated Galf 9-heptadecyl thioglycoside was prepared by Lewis acid-catalyzed thioglycosidation of 1, 2,3,5,6-penta-O-acyl-D-galactofuranose with 9-heptadecanethiol, and subsequently converted to the corresponding sulfone using m-CPBA. Both Galf 9-heptadecyl thioglycoside and sulfone displayed in vitro inhibition (MIC) of the growth of Mycobacterium smegmatis below 5 mu g/mL, while Galf 1-octyl thioglycoside gave no inhibition at or below 32 mu g/mL. (c) 2007 Elsevier Ltd. All rights reserved.
Family of Diazapentalene Chromophores and Narrow-Band-Gap Polymers: Synthesis, Halochromism, Halofluorism, and Visible–Near Infrared Photodetectivity
作者:Gang Qian、Ji Qi、James A. Davey、James S. Wright、Zhi Yuan Wang
DOI:10.1021/cm300938s
日期:2012.6.26
A family of pyrrolo[3,4-c]pyrrol-1(2H)-one (PPO) and 2,5-diazapentalene (DAP) chromophores and DAP-containing polymers were synthesized, and their optical and electrochemical properties were studied. PPO and DAP chromophores are readily obtained by chemical transformation of the lactam unit in diketopyrrolopyrrole (DPP) dyes and can be used as versatile building blocks for construction of a variety of conjugated low-band-gap compounds and polymers. In comparison with the DPP chromophores, PPO and DAP chromophores have narrower energy gaps and low-lying HOMO levels in the order DPP > PPO > DAP. Interestingly, the PPO and DAP chromophores exhibit unique visible and near-infrared halochromic and halofluoric properties. The emission spectrum of DAP-containing polymer 6d covers the telecommunication window including the wavelength of 1310 nm. The photodetector with a device configuration of ITO/PEDOT:PSS (35 nm)/active layer (100 nm)/Al (100 nm) was fabricated using a blend of polymer 6d and [6,6]-phenyl-C-61-butyric acid methyl ester (PC61BM) in a weight ratio of 1:3 as the active layer and exhibited photocurrent spectral response from 400 to 1000 nm and the detectivity in an order of 10(11) Jones at 800 nm.