139140-58-2Relevant academic research and scientific papers
Depolymerization of Hydroxylated Polymers via Light-Driven C-C Bond Cleavage
Nguyen, Suong T.,McLoughlin, Elizabeth A.,Cox, James H.,Fors, Brett P.,Knowles, Robert R.
, p. 12268 - 12277 (2021)
The accumulation of persistent plastic waste in the environment is widely recognized as an ecological crisis. New chemical technologies are necessary both to recycle existing plastic waste streams into high-value chemical feedstocks and to develop next-generation materials that are degradable by design. Here, we report a catalytic methodology for the depolymerization of a commercial phenoxy resin and high molecular weight hydroxylated polyolefin derivatives upon visible light irradiation near ambient temperature. Proton-coupled electron transfer (PCET) activation of hydroxyl groups periodically spaced along the polymer backbone furnishes reactive alkoxy radicals that promote chain fragmentation through C-C bond β-scission. The depolymerization produces well-defined and isolable product mixtures that are readily diversified to polycondensation monomers. In addition to controlling depolymerization, the hydroxyl group modulates the thermomechanical properties of these polyolefin derivatives, yielding materials with diverse properties. These results demonstrate a new approach to polymer recycling based on light-driven C-C bond cleavage that has the potential to establish new links within a circular polymer economy and influence the development of new degradable-by-design polyolefin materials.
Pyridine compounds for treating leukotriene-related diseases
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, (2008/06/13)
STR1 This invention relates to compounds of formula (I) which are useful as leukotriene antagonists.
(E)-3-[[[[6-(2-Carboxyethenyl)-5-[[8-(4-methoxyphenyl)octyl]oxy]-2- pyridinyl]-methyl]thio]methyl]benzoic acid and related compounds: High affinity leukotriene B4 receptor antagonists
Daines,Chambers,Eggleston,Foley,Griswold,Haltiwanger,Jakas,Kingsbury,Martin,Pendrak,Schmidt,Tzimas,Sarau
, p. 3327 - 3336 (2007/10/02)
(E)-3-[[[[6-(2-Carboxyethenyl)-5-[[8-(4-methoxyphenyl)octyl]oxy]-2- pyridinyl]-methyl]thio]methyl]benzoic acid (11, SB 201993) is a novel, potent LTB4 receptor antagonist. Compound 11 arose from a structure-activity study of a series of trisubstituted pyridines that demonstrated LTB4 receptor antagonist activity. The placement of an additional methylene unit in the sulfur containing chain linking the pyridine and benzoic acid moieties of lead compound 8 (K(i) = 80 nM) resulted in a greater than 10-fold increase in receptor affinity. Additionally, in this new series of compounds, the oxidation state of the sulfur was found to be critical to the activity, i.e., the sulfoxide and sulfone showed substantially lower affinity for the LTB4 receptor. Compound 11 competitively inhibits the binding of [3H]LTB4 to LTB4 receptors on human polymorphonuclear leukocutes with a K(i) of 7.1 nM and blocks both the LTB4-induced calcium mobilization and the LTB4-induced degranulation responses in these cells with IC50 values of 131 and 271 nM, respectively. Compound 11 demonstrated oral LTB4 antagonist activity as well as topical antiinflammatory activity in the mouse.
Trisubstituted Pyridine Leukotriene B4 Receptor Antagonists: Synthesis and Structure-Activity Relationships
Daines, Robert A.,Chambers, Pamela A.,Pendrak, Israil,Jakas, Dalia R.,Sarau, Henry M.,et al.
, p. 3321 - 3332 (2007/10/02)
A series of trisubstituted pyridines have been prepared that exhibit in vitro leukotriene B4 (LTB4, 1) receptor antagonist activity.Previous disubstituted pyridines from these labs showed high affinity for the LTB4 receptor but demonstrated agonist activity in functional assays (e.g., 2, Ki = 1 nM).Compound 4, the initial lead compound of this new series, showed only modest affinity by comparison (Ki = 282 nM); however, 4 was a receptor antagonist with no demonstrable agonist activity up to 10 μM.Subsequent modifications of the lipid tail and aryl head group region led to the discovery of aniline 50 (SB 201146).This compound, also free of agonist activity, possesses high affinity for the LTB4 receptor (Ki = 4.7 nM).
