We intend to continue synthesis of new geometric isomers of vitamin A, A2 and related compounds, design stereoselective synthetic schemes to known isomers an to study properties of such new isomers. The latter will include investigation of photochemical properties of these polyenes, detailed structural studies including x-ray crystal structures and solution nmr studies. The aldehyde form of these new isomers and analogs will be prepared for preparation of the corresponding pigment analogs. A detailed analysis is expected to lead to a better understanding of the binding site of opsin. In the coming year we also expect to begin a systematic study on new geometric isomers of carotenoids.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK017806-12
Application #
3225867
Study Section
Bio-Organic and Natural Products Chemistry Study Section (BNP)
Project Start
1975-01-01
Project End
1987-06-30
Budget Start
1986-07-01
Budget End
1987-06-30
Support Year
12
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Hawaii
Department
Type
Schools of Arts and Sciences
DUNS #
121911077
City
Honolulu
State
HI
Country
United States
Zip Code
96822
Liu, Robert S H; Colmenares, Leticia U (2003) The molecular basis for the high photosensitivity of rhodopsin. Proc Natl Acad Sci U S A 100:14639-44
Liu, Robert S H (2002) Introduction to the symposium-in-print: photoisomerization pathways, torsional relaxation and the hula twists. Photochem Photobiol 76:580-3
Liu, R S; Hammond, G S (2001) Examples of hula-twist in photochemical cis- trans isomerization. Chemistry 7:4537-44
Liu, R S (2001) Photoisomerization by hula-twist: a fundamental supramolecular photochemical reaction. Acc Chem Res 34:555-62
Muthyala, R; Watanabe, D; Asato, A E et al. (2001) The nature of the delocalized cations in azulenic bacteriorhodopsin analogs. Photochem Photobiol 74:837-45
Liu, R S; Hammond, G S (2000) The case of medium-dependent dual mechanisms for photoisomerization: one-bond-flip and hula-twist. Proc Natl Acad Sci U S A 97:11153-8
Imai, H; Hirano, T; Terakita, A et al. (1999) Probing for the threshold energy for visual transduction: red-shifted visual pigment analogs from 3-methoxy-3-dehydroretinal and related compounds. Photochem Photobiol 70:111-5
Li, X Y; Liu, R S (1995) Photostationary state compositions of retinal and related compounds included in beta-lactoglobulin. Effects of protein host on isomer distribution of polyene substrates. Photochem Photobiol 62:361-6
Asato, A E; Peng, A; Hossain, M Z et al. (1993) Azulenic retinoids: novel nonbenzenoid aromatic retinoids with anticancer activity. J Med Chem 36:3137-47
Liu, R S; Krogh, E; Li, X Y et al. (1993) Analyzing the red-shift characteristics of azulenic, naphthyl, other ring-fused and retinyl pigment analogs of bacteriorhodopsin. Photochem Photobiol 58:701-5

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