| A photochemical study of (E,E,E,E)-2-[9-(2-hydroxyethyl)imino-3,7-dimethyl-1,3,5,7-decatrien-1-yl]- 1,3,3-trimethylcyclohexene, a derivative of all-trans-retinal and ethanolamine. | |
| | |
MedLine Citation:
|
PMID: 14556318 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
A derivative of all-trans-retinal (RAL) and ethanolamine, A2-E, is the main fluorescent component of human retinal lipofuscin. The accumulation of lipofuscin has been correlated with exposure to ambient radiation and loss of photoreceptors. A possible precursor to A2-E is the imine formed from RAL and ethanolamine. This compound, (E,E,E,E)-2-[9-(2-hydroxyethyl)imino-3,7-dimethyl-1,3,5,7- decatrien-1-yl]-1,3,3-trimethylcyclohexene (HIDD), has been synthesized and structurally characterized. The photophysical and photochemical properties of HIDD and its protonated form, HIDD-H+, have been investigated using steady-state and time-resolved methods. Both HIDD and HIDD-H+ are weakly fluorescent, and the fluorescence lifetime and quantum yield for HIDD are ca 0.6 ns and 4.0 +/- 0.5 x 10(-4), respectively. HIDD forms a triplet excited state on direct excitation that decays with kd = 3.4 x 10(4) s-1. The extinction coefficient and quantum yield of intersystem crossing for the HIDD triplet are measured as 7.6 +/- 1.3 x 10(4) M-1 cm-1 and 0.055 +/- 0.006, respectively. The triplet excited state of HIDD-H+ can be sensitized by triplet energy transfer and has a decay rate constant of 1.6 x 10(4) s-1. The lifetime of the HIDD triplet excited state is observed to decrease with increasing concentration of the well-known electron or hydrogen atom donors, 2,3,5,6-tetramethyl-1,4-phenylenediamine and 2,3,5-trimethylhydroquinone, and the bimolecular rate constants for these reactions are approximately 5.4 x 10(6) M-1 s-1 and 1.7 x 10(8) M-1 s-1, respectively. These types of reactions may model photooxidative mechanisms of damage in the retina. |
| | |
Authors:
|
Willa S Harper; Elizabeth R Gaillard |
Related Documents
:
|
16037418 - Control and detection of singlet-triplet mixing in a random nuclear field. 11811528 - Photogeneration of singlet oxygen (1o2) and free radicals (sen*-, o2*-) by tetra-bromin... 19267468 - Long-lived photogenerated states of alpha-oligothiophene-acridinium dyads have triplet ... 10053128 - Dynamic nuclear polarization in pulsed endor experiments. 16951678 - Origin of defect-insensitive emission probability in in-containing (al,in,ga)n alloy se... 18575538 - A single-crystal source of path-polarization entangled photons at non-degenerate wavele... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
|
Title: Photochemistry and photobiology Volume: 78 ISSN: 0031-8655 ISO Abbreviation: Photochem. Photobiol. Publication Date: 2003 Sep |
Date Detail:
|
Created Date: 2003-10-14 Completed Date: 2003-12-11 Revised Date: 2007-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 0376425 Medline TA: Photochem Photobiol Country: United States |
Other Details:
|
Languages: eng Pagination: 298-305 Citation Subset: IM |
Affiliation:
|
Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Alkenes
/
chemistry* Cyclohexanes / chemistry* Ethanolamine / chemistry* Fluorescence Photochemistry* Retinaldehyde / chemistry* |
| Grant Support | |
ID/Acronym/Agency:
|
EY12344/EY/NEI NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/(E,E,E,E)-2-(9-(2-hydroxyethyl)imino-3,7-dimethyl-1,3,5,7-decatrien-1-yl)- 1,3,3-trimethylcyclohexene; 0/Alkenes; 0/Cyclohexanes; 116-31-4/Retinaldehyde; 141-43-5/Ethanolamine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Initial characterization of the primary photochemistry of AppA, a blue-light-using flavin adenine di...
Next Document: Sequential effects of ultraviolet radiation on the histomorphology, cell density and antioxidative s...