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Application of resonance raman microscopy to in vivo carotenoid

100%

Uragami C., Yamashita E., Gall A., Robert B., Hashimoto H.

Acta Biochimica Polonica

2012

vol. 59

issue 1

53-56

The high antioxidant activity of astaxanthin has been attracted considerable attention in these days. One of the major antioxidant activities of this carotenoid is anti-photoaging. We have been focusing our attention on this particular issue. The anti-photoaging activity should be functioning in inner skin. In this study we tried to find out the fact that astaxanthin that has been swabbed on the outer surface of the skin has really passed through and reached to the inner skin. For this purpose resonance Raman microscopy was applied to the rat skin sample on which astaxanthin was swabbed on its outer surface. Astaxanthin gives rise to a unique Raman spectrum that is characteristic of its molecular structure. Therefore, we can easily identify the presence or absence of astaxanthin in the area of the rat skin that is subjected to this spectroscopic measurement. We used 532 nm laser light for probing the resonance Raman scattering of astaxanthin. Astaxanthin shows three strong Raman lines at 1508, 1145, and 993 cm-1. These three lines are ascribable to the C=C stretching, C-C stretching, and C-CH3 in-plane rocking vibrational modes, respectively. We have constructed confocal Raman microscope that has the spatial resolution of ca. 500 nm. Three-dimensional mapping of the Raman spectrum of astaxanthin has been performed in order to determine its distribution in the rat skin.

Polarization angle dependence of stark absorption spectra of spirilloxanthin bound to the reconstituted LH1 complexes using LH1-subunits isolated from the purple photosynthetic bacterium Rhodospirillum rubrum

86%

Horibe T., Nakagawa K., Kusumoto T., Fujii R., Cogdell R. J., Nango M., Hashimoto H.

Acta Biochimica Polonica

2012

vol. 59

issue 1

97-100

Reconstituted LH1 complexes were prepared using the LH1 subunit-type complexes, isolated from the purple photosynthetic bacterium Rhodospirillum (Rs.) rubrum, and purified all-trans spirilloxanthin. Stark absorption spectra of spirilloxanthin bound to both the native and reconstituted LH1 complexes were compared in different polarization angles (χ) against the external electric field. From the polarization angle dependence of the Stark absorption spectra, two angles were determined in reference to the direction of transition dipole moment (m) of spirilloxanthin: one is the change in polarizability upon photoexcitation (Δα), θΔα and the other is the change in static dipole moment upon photoexcitation (Δμ), θΔμ. Despite the symmetric molecular structure of all-trans spirilloxanthin, its Stark absorption spectra show pronounced values of Δμ. This large Δμ values essentially caused by the effect of induced dipole moment through Δα both in the cases for native and reconstituted LH1 complexes. However, slightly different values of θΔα and θΔμ observed for the native LH1 complex suggest that spirilloxanthin is asymmetrically distorted when bound to the native LH1 complex and gives rise to intrinsic Δμ value.

Femtosecond stimulated Raman spectroscopy of the dark S1 excited state of carotenoid in photosynthetic light harvesting complex

73%

Yoshizawa M., Nakamura R., Yoshimatsu O., Abe K., Sakai S., Nakagawa K., Fujii R., Nango M., Hashimoto H.

Acta Biochimica Polonica

2012

vol. 59

issue 1

49-52

Vibrational dynamics of the excited state in the light-harvesting complex (LH1) have been investigated by femtosecond stimulated Raman spectroscopy (FSRS). The native and reconstituted LH1 complexes have same dynamics. The ν1 (C=C stretching) vibrational mode of spirilloxanthin in LH1 shows ultrafast high-frequency shift in the S1 excited state with a time constant of 0.3 ps. It is assigned to the vibrational relaxation of the S1 state following the internal conversion from the photoexcited S2 state.

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3 Acta Biochimica Polonica

3 2012

3 Hashimoto H.

2 Fujii R.

2 Nakagawa K.

2 Nango M.

1 Abe K.

1 Cogdell R. J.

1 Gall A.

1 Horibe T.

1 Kusumoto T.

1 Nakamura R.

1 Robert B.

1 Sakai S.

1 Uragami C.

1 Yamashita E.

1 Yoshimatsu O.

1 Yoshizawa M.

Search results

Application of resonance raman microscopy to in vivo carotenoid

Polarization angle dependence of stark absorption spectra of spirilloxanthin bound to the reconstituted LH1 complexes using LH1-subunits isolated from the purple photosynthetic bacterium Rhodospirillum rubrum

Femtosecond stimulated Raman spectroscopy of the dark S1 excited state of carotenoid in photosynthetic light harvesting complex