1428-33-7Relevant academic research and scientific papers
Cyclizations of 5-hexenyl, 6-heptenyl, 7-octenyl, and 8-nonenyl radicals. The kinetic and regiochemical impact of fluorine and oxygen substituents
Li, Anrong,Shtarev, Alexander B.,Smart, Bruce E.,Yang, Zhen-Yu,Lusztyk, Janusz,Ingold, Keith U.,Bravo, Anna,Dolbier Jr., William R.
, p. 5993 - 5999 (1999)
Using competition kinetic methodology, rate constants for cyclizations of a series of hydrofluorocarbon (HFC) and ether 5-hexenyl, 6-heptenyl, and 7-octenyl radicals have been determined. Remarkably large rate constants (> 107 s-1) have been observed for 6-exo-cyclizations of 1,1,2,2-tetrafluoro- and 1,1,2,2,3,3,4,4,-octafluoro-6-heptenyl radicals (> 103 those of analogous hydrocarbon radicals), whereas HFC hexenyl and heptenyl ethers exhibit lower cyclization reactivity, as do HFC 7-octenyl radical systems, which cyclize in an endo manner. HFC 8-nonenyl radicals were not observed to cyclize. The results can be rationalized in terms of transition state polar influences, though other factors may also play significant roles.
Synthesis and Evaluation of Phospholipid Analogues as Inhibitors of Cobra Venom Phospholipase A2
Yuan, Wei,Berman, Richard J.,Gelb, Michael H.
, p. 8071 - 8081 (2007/10/02)
Analogues of phospholipids that contain fluoro ketone, ketone, and alcohol replacements for the ester at the 2-position of the glycerol backbone have been prepared and analyzed as inhibitors of phospholipase A2 from Naja naja naja venom.Phospholipid analogues were studied that contain two alkyl chains as well as single chain compounds that lack carbon-1 of the glycerol backbone and the attached acyl unit.Compounds that contain both long and medium length alkyl chains were studied.All of the potential inhibitors were tested in a well-defined mixed micelle system in which both the substrates and the inhibitors have been incorporated into Triton X-100 micelles.Surprisingly, the best inhibitors studied were the single chain fluoro ketones despite the fact that the enzyme has a strong preference for two-chain lipids.The most potent compound was found to have a dissociation constant some 600-3000-fold lower than the Michaelis constant for dipalmitoyl phosphatidylcholine substrate. 19F NMR studies of the fluoro ketone phospholipid analogues in micelles show that whereas the single chain compounds are partially in the hydrated-ketone form, the two-chain compounds are less than 0.1percent hydrated.In every case studied, potent inhibition of phospholipase A2 was observed only with those compounds that are significantly hydrated in the micelle, and it is suggested that the hydrated fluoro ketone containing phospholipid analogues are the species responsible for the inhibition.In addition, the single chain fluoro ketones were better inhibitors than single and double chain alcohol and ketone analogues.Previous studies have been show that the cobra venom enzyme is activated by choline-containing lipids, and evidence is presented for the binding of the hydrated fluoro ketone inhibitors selectively to the activated enzyme.
