• Journal of Photoscience
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• 제8권2호
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• pp.70-73
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• 2001

The chlorin-bromine building block was constructed and applied to synthesize $\delta$-bromo compounds of methyl pyropheophorbide-a. The visible spectra of the title compounds were discussed.

• Bulletin of the Korean Chemical Society
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• 제2권4호
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• pp.152-157
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• 1981

2'-(9"-Anthracenecarbonyloxy)ethyl pyropheophorbide a, methyl 3a-(9'-anthracenecarbonyloxy)pyropheophorbide a, 2'-(4"-phenylbenzoyloxy)ethyl pyropheophorbide a, and methyl 3a-(4'-phenylbenzoyloxy)pyropheophorbide a were prepared from chlorophyll a and b. Nuclear magnetic resonance study showed that the sandwich conformation is more favorable in 2'-(9"-anthracenecarbonyloxy)ethyl pyropheophorbide a than it is in other compounds.

• Journal of Photoscience
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• 제8권2호
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• pp.71-71
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• 2001

• Journal of Photoscience
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• 제8권2호
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• pp.75-77
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• 2001

The Grignard reaction of methyl pyropheophorbide-a (MPP-a) was performed to introduce lengthy alkyl chain for improving lipophilicity. After the introduction of alkyl chain to the both of carbonyls, peripheral aldehyde and cyclopentanone, the obtained diol 3 was subjected to dehydration to give monodehydrate product 4 selectively. The Qy band of prepared compounds were affected by the substituents on the Qy axis (N$\sub$21/-N$\sub$23/).

• Journal of Photoscience
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• 제9권2호
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• pp.178-181
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• 2002

Pyropheophorbide and pheophorbide-photosensitizers as chlorin analogues are promising new compounds for PDT because the chlorin analogues are activated with much longer red light at > 670nm and produce less long-term normal tissue phototoxicity than Photofrin. The various chlorin derivatives can be obtained by moditying peripheral substituted group among which meso-H, vinyl group and exocyclic ring are the most active positions. These characteristics prompted us to introduce various groups for constructing modified pyropheophorbide and pheophorbide a compounds. A stereospecific introduction of various double bonds at 3-position was performed to methylpheophorbide a to give a long hydrophobic moiety and cyclic derivatives. Chlorin-C$_{60}$ dyad and chlorin- $C_{60}$-porphyrin triad also were easily prepared by the reaction of terminal aldehyde of methyl pyropheophorbide a. For the reaction on meso $\delta$-position bromination and Vismeier formylation can occur. N,N-dimethylaminoacrolein also reacted on $\delta$-position and was cyclized to isobacteriochlorin, but other modification has not been succeeded. Exocyclic keto function was also modified to give purpurin derivatives, bicyclic and spiro compounds. In this presentation we report a series of modified pyropheophorbide and pheophorbide a derivatives.s.

• Journal of Photoscience
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• 제8권1호
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• pp.23-25
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• 2001

The methyl pheophorbide-a (MP-a) and methyl pyropheophorbide-a (MPP-a) were modified by reaction of exocyclic ketone in E-ring with nucleophilic reagent and several chlorin derivatives were synthesized. The change of the structure in E-ring served an expanding conjugation region and introduction of electron-withdrawing group, which strongly influenced the visible spectra. The Qy bands of synthesized compounds were affected by the substituents on the Qy axis(N$\sub$21/-N$\sub$23/).

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3473-3476
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• 2011

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.205-213
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• 2009

This study reports on the geometry optimizations and electronic structure calculations for methyl pyropheophorbide (MPPa), tropolonyl methyl pyropheophorbides (TMPPa, ITMPPa), and cationic tropolonyl methyl pyropheophorbides ($TMPPa^+{{\cdot}BF_4}^-,\;ITMPPa^+{{\cdot}BF_4}^-,\;TMPPa^+,\;and\;ITMPPa^+$) using Local Spin Density Approximation (LSDA/ 6-31G*) and the Restricted Hatree-Fock (RHF/6-31G*) level theory. From the calculated results, we found that substituted cationic tropolonyl groups have larger structural effects than those of substituted neutral tropolonyl groups. The order of structural change effects is $ITMPPa^+ > ITMPPa^+{{\cdot}BF_4}^-$ > ITMPPa, as a result of the isopropyl group. Because it is an electron-releasing group, the substituted isopropyl group electronic effect on a 3-position tropolone increases the Highest Occupied Molecular Orbital and Lowest Unoccupied Molecular Orbital (HOMO-LUMO) energy gap. It was constituted that the larger the cationic characters of these photosensitizers, the smaller the HOMOLUMO band gaps are. The orbital energies of the cationic systems and the ions are stronger than those of a neutral system because of a strong electrostatic interaction. However, this stabilization of orbital energies are counteracted by the distortion of chlorin macrocycle, which results in a large destabilization of chlorin-based compound HOMOs and smaller destabilization of LUMOs as shown in TMPPa (ITMPPa), $TMPPa^+{{\cdot}BF_4}^- (ITMPPa^+{{\cdot}BF_4}^-),\;and\;TMPPa^+\;(ITMPPa^+)$ of Figure 6 and Table 6-7. These results are in reasonable agreement with normal-coordinate structural decomposition (NSD) results. The HOMO-LUMO gap is an important factor to consider in the development of photodynamic therapy (PDT).