2009
Competing Pathways in the Photo-Favorskii Rearrangement and Release of Esters: Studies on Fluorinated p-Hydroxyphenacyl-Caged GABA and Glutamate Phototriggers
STENSRUD, Kenneth F.; Jihyun NOH; Karl KANDLER; Jakob WIRZ; Dominik HEGER et. al.Základní údaje
Originální název
Competing Pathways in the Photo-Favorskii Rearrangement and Release of Esters: Studies on Fluorinated p-Hydroxyphenacyl-Caged GABA and Glutamate Phototriggers
Název česky
Competing Pathways in the Photo-Favorskii Rearrangement and Release of Esters: Studies on Fluorinated p-Hydroxyphenacyl-Caged GABA and Glutamate Phototriggers
Autoři
STENSRUD, Kenneth F.; Jihyun NOH; Karl KANDLER; Jakob WIRZ; Dominik HEGER a Richard GIVENS
Vydání
JOURNAL OF ORGANIC CHEMISTRY, 2009, 0022-3263
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10403 Physical chemistry
Stát vydavatele
Spojené státy
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 4.219
Kód RIV
RIV/00216224:14310/09:00036419
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000268480300012
Klíčová slova česky
RESOLVED RESONANCE RAMAN; PHOTOREMOVABLE PROTECTING GROUPS; DENSITY-FUNCTIONAL THEORY; TRIPLET-STATE; EXCITED-STATE; PHOTODEPROTECTION; SPECTROSCOPY; HYDROXYACETOPHENONE; ABSORPTION; ACTIVATION
Klíčová slova anglicky
RESOLVED RESONANCE RAMAN; PHOTOREMOVABLE PROTECTING GROUPS; DENSITY-FUNCTIONAL THEORY; TRIPLET-STATE; EXCITED-STATE; PHOTODEPROTECTION; SPECTROSCOPY; HYDROXYACETOPHENONE; ABSORPTION; ACTIVATION
Příznaky
Recenzováno
Změněno: 17. 8. 2009 13:44, doc. Mgr. Dominik Heger, Ph.D.
V originále
Three new trifluoromethylated p-hydroxyphenacyl (pHP)-caged gamma-aminobutyric acid (GABA) and glutamate (Glu) derivatives have been examined for their efficacy as photoremovable protecting groups in aqueous solution. Through the replacement of hydrogen with fluorine, e.g., a m-trifluoromethyl or a m-trifluoromethoxy versus m-methoxy substituents on the pHP chromophore, modest increases in the quantum yields for the release of amino acids GABA and glutamate as well as improved lipophilicity were realized. The pH P triplet undergoes a photo-Favorskii rearrangement with concomitant release of the amino acid substrate. Deprotonation competes with the rearrangement from the triplet excited state and yields the pHP conjugate base that, upon reprotonation, regenerates the starting ketoester, a chemically unproductive or "energy-wasting" process. When picosecond pump-probe spectroscopy is employed, GABA derivatives 2-5 are characterized by short triplet lifetimes, a manifestation of their rapid release of GABA. The bioavailability of released GABA at the GABA(A) receptor improved when the release took place from m-OCF3 (2) but decreased for m-CF3 (3) when compared with the parent pHP derivative. These studies demonstrate that pK(a) and lipophilicity exert significant but sometimes opposing influences on the photochemistry and biological activity of pHP phototriggers.
Česky
Three new trifluoromethylated p-hydroxyphenacyl (pHP)-caged gamma-aminobutyric acid (GABA) and glutamate (Glu) derivatives have been examined for their efficacy as photoremovable protecting groups in aqueous solution. Through the replacement of hydrogen with fluorine, e.g., a m-trifluoromethyl or a m-trifluoromethoxy versus m-methoxy substituents on the pHP chromophore, modest increases in the quantum yields for the release of amino acids GABA and glutamate as well as improved lipophilicity were realized. The pH P triplet undergoes a photo-Favorskii rearrangement with concomitant release of the amino acid substrate. Deprotonation competes with the rearrangement from the triplet excited state and yields the pHP conjugate base that, upon reprotonation, regenerates the starting ketoester, a chemically unproductive or "energy-wasting" process. When picosecond pump-probe spectroscopy is employed, GABA derivatives 2-5 are characterized by short triplet lifetimes, a manifestation of their rapid release of GABA. The bioavailability of released GABA at the GABA(A) receptor improved when the release took place from m-OCF3 (2) but decreased for m-CF3 (3) when compared with the parent pHP derivative. These studies demonstrate that pK(a) and lipophilicity exert significant but sometimes opposing influences on the photochemistry and biological activity of pHP phototriggers.
Návaznosti
| MSM0021622413, záměr |
|