627-31-6Relevant articles and documents
Evaluation of delocalized lipophilic cationic dyes as delivery vehicles for photosensitizers to mitochondria
Ngen, Ethel J.,Rajaputra, Pallavi,You, Youngjae
, p. 6631 - 6640 (2009)
Mitochondria are attractive targets in photodynamic therapy. Two conjugates: TPP-Rh (a porphyrin-rhodamine B conjugate) and TPP-AO (a porphyrin-acridine orange conjugate), each possessing a single delocalized lipophilic cation, were designed and synthesized as photosensitizers. Their ability to target the mitochondria for photodynamic therapy was evaluated. The conjugates were synthesized by conjugating a monohydroxy porphyrin (TPP-OH) to rhodamine B (Rh B) and acridine orange base (AO), respectively, via a saturated hydrocarbon linker. To evaluate the efficiency of the conjugates as photosensitizers, their photophysical properties and in vitro photodynamic activities were studied in comparison to those of TPP-OH. Although fluorescence energy transfer (FRET) was observed in the conjugates, they were capable of generating singlet oxygen at rates comparable to TPP-OH. Biologically, exciting results were observed with TPP-Rh, which showed a much higher phototoxicity [IC50, 3.95 μM: irradiation of 400-850 nm light (3 mW cm-2) for 1 h] than either TPP-OH or Rh B (both, IC50, >20 μM) without significant dark toxicity at 20 μM. This improved photodynamic activity might be due to a greater cellular uptake and preferential localization in mitochondria. The cellular uptake of TPP-Rh was 8 and 14 times greater than TPP-OH and Rh B, respectively. In addition, fluorescence imaging studies suggest that TPP-Rh localized more in mitochondria than TPP-OH. On the other hand, TPP-AO showed some dark toxicity at 10 μM and stained both mitochondria and nucleus. Our study suggests that conjugation of photosensitizers to Rh might provide two benefits, higher cellular uptake and mitochondrial localization, which are two important subjects in photodynamic therapy.
DICARBOXIMIDE DERIVATIVES OF BERBAMINE, THE PREPARATION AND USE THEREOF
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Page/Page column 0116, (2013/06/28)
The present invention relates to a novel dicarboximide derivative of berbamine represented by formula I, including, but not limited to, a phthalimide derivative of berbamine and an aromatic heterocyclic dicarboximide derivative of berbamine, or a pharmaceutically acceptable salt thereof, to a process for preparation of the same, to a pharmaceutical composition comprising said compound and to use thereof in manufacture of an antitumor medicament.
Attempted synthesis of 1,3,5-triphenyl-2,4,9-trithia-1,3,5-triplumbaadamantane. Decomposition of organolead iodides
Kobayashi, Michio,Latour, Stéphan,Wuest, James D.
, p. 2908 - 2913 (2008/10/08)
MNDO calculations suggest that the strength of the bridgehead carbon-hydrogen bond in 2,4,9-trithia-1,3,5-triplumbaadamantane (2a) should be only 54 kcal/mol and the hydride affinity of the corresponding bridgehead cation 2a+ should be only 215 kcal/mol. As a donor of hydrogen atoms or hydride, plumbaadamantane 2a should therefore be even more reactive than the analogous stannaadamantane 1a. Unfortunately, substituted derivative 2b could not be prepared from (Ph3PbCH2)3CH by controlled iodinolysis followed by treatment of the intermediate hexaiodide (PhI2PbCH2)3CH with Ph3SnSSnPh3. This failure results in part from the tendency of organolead diiodides R2PbI2 to undergo redistribution reactions that produce unstable triiodides RPbI3. Diiodides capable of intramolecular redistributions are particularly reactive. The resulting triiodides then decompose by a formal reductive elimination of RI and PbI2. Since the iodinolysis of (cyclopropylmethyl)triphenylplumbane (11) yields mainly (iodomethyl)cyclopropane instead of ring-opened products derived from cyclopropylmethyl cations or radicals, we suggest that the reductive elimination of RI and PbI2 from RPbI3 is concerted.
