1
|
Abstract
The synthesis of (+)-omphadiol and (+)-pyxidatol C was achieved through two independent strategies. For the synthesis of (+)-omphadiol, dicyclopentadienone was used as the workbench on which the three contiguous stereocenters of the cyclopentane could be introduced selectively. These include a tertiary alcohol and a selective protonation of an enolate. A ring-closing metathesis and a cyclopropanation concluded the synthesis. For the synthesis of pyxidatol C, we used the epoxide derived from (R)-linalool that was transformed to cyclopentane 23. After chain extension, another ring-closing metathesis followed by oxidation state changes and finally a cyclopropanation led to (+)-pyxidatol C.
Collapse
Affiliation(s)
- Gowrisankar Parthasarathy
- Institute for Organic Chemistry and Centre for Biomolecular Drug Research, Leibniz Universität Hannover , Schneiderberg 1B, 30167 Hannover, Germany
| | - Ulrike Eggert
- Institute for Organic Chemistry and Centre for Biomolecular Drug Research, Leibniz Universität Hannover , Schneiderberg 1B, 30167 Hannover, Germany
| | - Markus Kalesse
- Institute for Organic Chemistry and Centre for Biomolecular Drug Research, Leibniz Universität Hannover , Schneiderberg 1B, 30167 Hannover, Germany
| |
Collapse
|
2
|
Kim JE, McCamant DW, Zhu L, Mathies RA. Resonance Raman Structural Evidence that the Cis-to-Trans Isomerization in Rhodopsin Occurs in Femtoseconds. J Phys Chem B 2012; 105:1240-9. [PMID: 16755302 PMCID: PMC1473983 DOI: 10.1021/jp001236s] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Picosecond time-resolved resonance Raman spectroscopy is used to probe the structural changes of rhodopsin's retinal chromophore as the cis-to-trans isomerization reaction occurs that initiates vision. Room-temperature resonance Raman spectra of rhodopsin's photoproduct with time delays from -0.7 to 20.8 ps are measured using 2.2 ps, 480 nm pump and 1.5 ps, 600 nm probe pulses. Hydrogen-out-of-plane (HOOP) modes at 852, 871, and 919 cm(-1), fingerprint peaks at 1272, 1236, 1211, and 1166 cm(-1), and a broad red-shifted ethylenic band at 1530 cm(-1) are present at the earliest positive pump-probe time delay of 0.8 ps, indicating that the chromophore is already in a strained, all-trans configuration. Kinetic analyses of both the HOOP and ethylenic regions of the photoproduct spectra reveal that these features grow in with fast ( approximately 200 fs) and slow ( approximately 2-3 ps) components. These data provide the first structural evidence that photorhodopsin has a thermally unrelaxed, torsionally strained all-trans chromophore within approximately 1 ps, and possibly within 200 fs, of photon absorption. Following this ultrafast product formation, the all-trans chromophore cools and conformationally relaxes within a few picoseconds to form bathorhodopsin. This cooling process is revealed as an ethylenic frequency blue-shift of 6 cm(-1) (tau approximately 3.5 ps) as well as an ethylenic width narrowing (tau approximately 2 ps). The ultrafast production of photorhodopsin is likely accompanied by an impulsively driven, localized protein response. More delocalized protein modes are unable to relax on this ultrafast time scale enabling the chromophore-protein complex to store the large amounts of photon energy (30-35 kcal/mol) that are subsequently used to drive activating protein conformational changes.
Collapse
Affiliation(s)
- J E Kim
- Department of Chemistry, University of California, Berkeley, California 94720
| | | | | | | |
Collapse
|
3
|
Liu G, Romo D. Total synthesis of (+)-omphadiol. Angew Chem Int Ed Engl 2011; 50:7537-40. [PMID: 21761524 DOI: 10.1002/anie.201102289] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Indexed: 11/10/2022]
Affiliation(s)
- Gang Liu
- Department of Chemistry, Texas A&M University, P. O. Box 30012, College Station, TX 77842, USA
| | | |
Collapse
|
4
|
|
5
|
Pescitelli G, Sreerama N, Salvadori P, Nakanishi K, Berova N, Woody RW. Inherent Chirality Dominates the Visible/Near-Ultraviolet CD Spectrum of Rhodopsin. J Am Chem Soc 2008; 130:6170-81. [DOI: 10.1021/ja711009y] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Gennaro Pescitelli
- Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Pisa, via Risorgimento 35, I-56126 Pisa, Italy, Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, and Department of Chemistry, Columbia University, 3000 Broadway, MC 3114, New York 10027
| | - Narasimha Sreerama
- Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Pisa, via Risorgimento 35, I-56126 Pisa, Italy, Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, and Department of Chemistry, Columbia University, 3000 Broadway, MC 3114, New York 10027
| | - Piero Salvadori
- Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Pisa, via Risorgimento 35, I-56126 Pisa, Italy, Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, and Department of Chemistry, Columbia University, 3000 Broadway, MC 3114, New York 10027
| | - Koji Nakanishi
- Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Pisa, via Risorgimento 35, I-56126 Pisa, Italy, Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, and Department of Chemistry, Columbia University, 3000 Broadway, MC 3114, New York 10027
| | - Nina Berova
- Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Pisa, via Risorgimento 35, I-56126 Pisa, Italy, Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, and Department of Chemistry, Columbia University, 3000 Broadway, MC 3114, New York 10027
| | - Robert W. Woody
- Dipartimento di Chimica e Chimica Industriale, Università degli Studi di Pisa, via Risorgimento 35, I-56126 Pisa, Italy, Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, and Department of Chemistry, Columbia University, 3000 Broadway, MC 3114, New York 10027
| |
Collapse
|
6
|
Saito Y, Shinkai T, Yoshimura Y, Takahata H. A straightforward stereoselective synthesis of meso-, (S,S)- and (R,R)-2,6-diaminopimelic acids from cis-1,4-diacetoxycyclohept-2-ene. Bioorg Med Chem Lett 2007; 17:5894-6. [PMID: 17826999 DOI: 10.1016/j.bmcl.2007.07.106] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Revised: 07/24/2007] [Accepted: 07/26/2007] [Indexed: 11/16/2022]
Abstract
A straightforward synthesis of meso-2,6-diaminopimelic acid (DAP) meso-1 was developed from 1,4-diacetoxycyclohept-2-ene (2) via an oxidative ring cleavage. Subsequently, an enantio-divergent synthesis of (S,S)- and (R,R)-1 was performed using a homochiral monoacetate 7 available from 2 by enzymatic desymmetrization.
Collapse
Affiliation(s)
- Yukako Saito
- Faculty of Pharmaceutical Sciences, Tohoku Pharmaceutical University, Sendai 981-8558, Japan
| | | | | | | |
Collapse
|
7
|
Bosch L, Cordomí A, Domínguez M, Toledo D, Morillo M, Pérez JJ, Alvarez R, de Lera AR, Garriga P. A methyl group at C7 of 11-cis-retinal allows chromophore formation but affects rhodopsin activation. Vision Res 2006; 46:4472-81. [PMID: 17027899 DOI: 10.1016/j.visres.2006.07.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 07/27/2006] [Accepted: 07/28/2006] [Indexed: 10/24/2022]
Abstract
The newly synthesized 11-cis-7-methylretinal can form an artificial visual pigment with kinetic and spectroscopic properties similar to the native pigment in the dark-state. However, its photobleaching behavior is altered, showing a Meta I-like photoproduct. This behavior reflects a steric constraint imposed by the 7-methyl group that affects the conformational change in the binding pocket as a result of retinal photoisomerization. Transducin activation is reduced, when compared to the native pigment with 11-cis-retinal. Molecular dynamics simulations suggest coupling of the C7 methyl group and the beta-ionone ring with Met207 in transmembrane helix 5 in agreement with recent experimental results.
Collapse
Affiliation(s)
- Laia Bosch
- Departament d'Enginyeria Química, Universitat Politècnica de Catalunya, 08222 Terrassa, Catalonia, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Papper V, Kharlanov V, Schädel S, Maretzki D, Rettig W. New fluorescent probes for visual proteins. Part II. 5-(Oxo)penta-2,4-dienyl-p-(N,N-dimethylamino)benzoate. Photochem Photobiol Sci 2004; 2:1272-86. [PMID: 14717221 DOI: 10.1039/b306235j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new dual-fluorescent compound, 5-(oxo)penta-2,4-dienyl-p-(N,N-dimethylamino)benzoate (1), a derivative of dimethylaminobenzoic acid, has been synthesised and studied photophysically. This compound continues the series of potential fluorescent probes for visual and proton-pumping opsin proteins. The photophysical behaviour of this molecule, including charge-transfer interaction in the ground state and dual-fluorescence emission, is similar to that of the previously studied analogue cis-3-(oxo)propenyl-p-(N,N-dimethylamino)benzoate (cis-2). The presence of several theoretically calculated conformers of compound 2 was suggested to be responsible for the observed strongly red-shifted absorption and excitation wavelength dependence. These photophysical anomalies were also observed for molecule 1, though the models put forward to explain them in the cases of 1 and 2 are rather different. Based on theoretical calculations and experimental results, we propose that some of the stable conformers might be connected with either a charge-transfer complex or mesomeric interactions in the ground state. Upon changing the electronic nature of the oxo-pentadienyl acceptor moiety, e.g. protonation, chemical or biochemical reaction, the charge-transfer absorption disappears, which leads to a dramatic increase in the fluorescence quantum yield.
Collapse
Affiliation(s)
- Vladislav Papper
- Institute of Chemistry, Humboldt University, Brook-Taylor Strasse 2, D-12489 Berlin, Germany
| | | | | | | | | |
Collapse
|
9
|
Fujimoto Y, Xie R, Tully SE, Berova N, Nakanishi K. Synthesis of 11-cis-locked bicyclo[5.1.0]octanyl retinal and an enantioselective binding to bovine opsin. Chirality 2002; 14:340-6. [PMID: 11968076 DOI: 10.1002/chir.10076] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Both enantiomers of 13-(E) and 13-(Z) isomers of 11-cis-locked bicyclo[5.1.0]octanyl retinal were prepared by an improved synthesis and incubated with bovine opsin. The synthesis also establishes the absolute configuration of the enantiomers. Only one of the enantiomers binds to opsin, thus showing the steric restrictions regarding the middle polyene moiety of the retinoid molecule; this is in sharp contrast to the known leniency of the ring moiety binding site of retinoids. However, although one enantiomer is incorporated into the pigment, the circular dichroic spectrum of the pigment incorporating the bound enantiomer yields only a very weak Cotton effect, showing that, once incorporated, the bicyclo[5.1.0]octanyl chromophore is flattened by the opsin binding site. The titled retinoid was synthesized for study of the absolute conformation of the retinal pigment in rhodopsin.
Collapse
Affiliation(s)
- Yukari Fujimoto
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | | | | | | | | |
Collapse
|
10
|
Pan D, Ganim Z, Kim JE, Verhoeven MA, Lugtenburg J, Mathies RA. Time-resolved resonance Raman analysis of chromophore structural changes in the formation and decay of rhodopsin's BSI intermediate. J Am Chem Soc 2002; 124:4857-64. [PMID: 11971736 PMCID: PMC1440918 DOI: 10.1021/ja012666e] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Time-resolved resonance Raman microchip flow experiments are performed to obtain the vibrational spectrum of the chromophore in rhodopsin's BSI intermediate and to probe structural changes in the bathorhodopsin-to-BSI and BSI-to-lumirhodopsin transitions. Kinetic Raman spectra from 250 ns to 3 micros identify the key vibrational features of BSI. BSI exhibits relatively intense HOOP modes at 886 and 945 cm(-1) that are assigned to C(14)H and C(11)H=C(12)H A(u) wags, respectively. This result suggests that in the bathorhodopsin-to-BSI transition the highly strained all-trans chromophore has relaxed in the C(10)-C(11)=C(12)-C(13) region, but is still distorted near C(14). The low frequency of the 11,12 A(u) HOOP mode in BSI compared with that of lumirhodopsin and metarhodopsin I indicates weaker coupling between the 11H and 12H wags due to residual distortion of the BSI chromophore near C(11)=C(12). The C=NH(+) stretching mode in BSI at 1653 cm(-1) exhibits a normal deuteriation induced downshift of 23 cm(-1), implying that there is no significant structural rearrangement of the Schiff base counterion region in the transition of bathorhodopsin to BSI. However, a dramatic Schiff base environment change occurs in the BSI-to-lumirhodopsin transition, because the 1638 cm(-1) C=NH(+) stretching mode in lumirhodopsin is unusually low and shifts only 7 cm(-1) in D(2)O, suggesting that it has essentially no H-bonding acceptor. With these data we can for the first time compare and discuss the room temperature resonance Raman vibrational structure of all the key intermediates in visual excitation.
Collapse
Affiliation(s)
- Duohai Pan
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | | | | | | | | | | |
Collapse
|
11
|
Fujimoto Y, Ishihara J, Maki S, Fujioka N, Wang T, Furuta T, Fishkin N, Borhan B, Berova N, Nakanishi K. On the bioactive conformation of the rhodopsin chromophore: absolute sense of twist around the 6-s-cis bond. Chemistry 2001; 7:4198-204. [PMID: 11686599 DOI: 10.1002/1521-3765(20011001)7:19<4198::aid-chem4198>3.0.co;2-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Incubation of opsin with synthetic 6-s-locked retinoids 2a and 2b only led to pigment formation from the alpha-locked 2a, the CD spectrum of which was similar to that of native rhodopsin (Rh). This establishes that the 6-s-bond of the chromophore in rhodopsin is cis, and that its helicity is negative. Earlier cross-linking studies showed that the 11-cis to all-trans photoisomerization occurring in the batho-Rh to lumi-Rh conversion induces a flip over of the side carrying the ring moiety. The GTP-binding assay of pigment Rh-(2a), incorporating retinal analogue 2a, has shown that its activity is 80% that of the native pigment. That is, the overall conformation around the 6-s bond is retained in the steps leading to G-protein activation.
Collapse
Affiliation(s)
- Y Fujimoto
- Department of Chemistry, Columbia University, New York, NY 10027, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
|
13
|
Abstract
CASSCF and GAUSSIAN CIS calculations were performed on ground and excited states of different conformations of 11-cis-retinal protonated Schiff bases, the chromophore of rhodopsin, in order to study their chiroptical properties and attempt a correlation between absolute conformation and CD-spectral data. Geometries were taken from molecular models, from published rhodopsin models, and from retinal conformations obtained from molecular dynamics with geometry restraints. In all the cases studied we find that a positive sense of twist about the C12-C13 bond correlates with a calculated positive CD of the long wavelength absorption band; the twist of the C6-C7 bond modulates this primary contribution of the C12-C13 bond. The correlation of the beta-band with structural features is not straightforward. Calculations on bathorhodopsin lend support to the idea that this intermediate is a highly twisted all-trans-conformation.
Collapse
Affiliation(s)
- V Buss
- Institut für Physikalische und Theoretische Chemie der Gerhard-Mercator-Universität, D47048 Duisburg, Germany.
| |
Collapse
|
14
|
Sammelson RE, Kurth MJ. Carbon-carbon bond-forming solid-phase reactions. Part II. Chem Rev 2001; 101:137-202. [PMID: 11712191 DOI: 10.1021/cr000086e] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R E Sammelson
- Department of Chemistry, University of California, Davis, California 95616, USA
| | | |
Collapse
|
15
|
Liu RS, Hammond GS. The case of medium-dependent dual mechanisms for photoisomerization: one-bond-flip and hula-twist. Proc Natl Acad Sci U S A 2000; 97:11153-8. [PMID: 11016972 PMCID: PMC17169 DOI: 10.1073/pnas.210323197] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This paper critically reviews examples in the literature of photochemical cis-trans isomerization paying particular attention to the medium effect and accompanied conformational changes. A case is made that the Hula-Twist mechanism, postulated in 1985 as a photochemical reaction pathway for a polyene chromophore imbedded in a protein binding cavity such as those of rhodopsin and bacteriorhodopsin, is also a dominant reaction pathway for a diene, or a longer polyene confined in a rigid (relative to isomerization rate) medium. The conventional one-bond-flip process is the preferred reaction pathway in a fluid medium. While defining experiments are proposed, this dual mechanistic approach successfully accounts for all examples in the literature on photoisomerization reactions whether involving conformational changes or not.
Collapse
Affiliation(s)
- R S Liu
- Department of Chemistry, University of Hawaii, 2545 The Mall, Honolulu, HI 96822, USA.
| | | |
Collapse
|
16
|
Lou J, Tan Q, Karnaukhova E, Berova N, Nakanishi K, Crouch RK. Synthetic retinals: convenient probes of rhodopsin and visual transduction process. Methods Enzymol 2000; 315:219-37. [PMID: 10736705 DOI: 10.1016/s0076-6879(00)15846-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Affiliation(s)
- J Lou
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | | | | | | | | | | |
Collapse
|