Leonard K A, Hall J P, Nelen M I, Davies S R, Gollnick S O, Camacho S, Oseroff A R, Gibson S L, Hilf R, Detty M R
Departments of Chemistry and Medicinal Chemistry, State University of New York at Buffalo, Buffalo, New York 14260, USA.
J Med Chem. 2000 Nov 16;43(23):4488-98. doi: 10.1021/jm000154p.
Cationic chalcogenopyrylium dyes 5 were synthesized in six steps from p-aminophenylacetylene (9), have absorption maxima in methanol of 623, 654, and 680 nm for thio-, seleno-, and telluropyrylium dyes, respectively, and generate singlet oxygen with quantum yields [Phi((1)O(2))] of 0.013, 0.029, and 0.030, respectively. Selenopyrylium dye 5-Se was phototoxic to cultured murine Colo-26 and Molt-4 cells. Initial acute toxicity studies in vivo demonstrate that, at 29 mg (62 micromol)/kg, no toxicity was observed with 5-Se in animals followed for 90 days under normal vivarium conditions. In animals given 10 mg/kg of 5-Se via intravenous injection, 2-8 nmol of 5-Se/g of tumor was found at 3, 6, and 24 h postinjection. Animals bearing R3230AC rat mammary adenocarcinomas were treated with 10 mg/kg of 5-Se via tail-vein injection and with 720 J cm(-2) of 570-750-nm light from a filtered tungsten lamp at 200 mW cm(-2) (24 h postinjection of 5-Se). Treated animals gave a tumor-doubling time of 9 +/- 4 days, which is a 300% increase in tumor-doubling time relative to the 3 +/- 2 days for untreated dark controls. Mechanistically, the mitochondria appear to be a target. In cultured R3230AC rat mammary adenocarcinoma cells treated with 0.1 and 1.0 microM 5-Se and light, mitochondrial cytochrome c oxidase activity was inhibited relative to cytochrome c oxidase activity in untreated cells. Irradiation of isolated mitochondrial suspensions treated with 10 microM dye 5-Se inhibited cytochrome c oxidase activity. The degree of enzyme inhibition was abated in a reduced oxygen environment. Superoxide dismutase, at a final concentration of 30 U, did not alter the photosensitized inhibition of mitochondrial cytochrome c oxidase by dye 5-Se. The data suggest that singlet oxygen may play a major role in the photosensitized inhibition of mitochondrial cytochrome c oxidase.
阳离子硫属代吡喃鎓染料5由对氨基苯乙炔（9）经六步合成，硫代、硒代和碲代吡喃鎓染料在甲醇中的最大吸收波长分别为623、654和680 nm，且分别以0.013、0.029和0.030的量子产率[Φ(¹O₂)]产生单线态氧。硒代吡喃鎓染料5-Se对培养的小鼠结肠26细胞和莫特4细胞具有光毒性。体内初步急性毒性研究表明，在正常饲养条件下，给动物注射29 mg（62 μmol）/kg的5-Se，观察90天未发现毒性。给动物静脉注射10 mg/kg的5-Se后，在注射后3、6和24小时，肿瘤中5-Se的含量为2 - 8 nmol/g。对携带R3230AC大鼠乳腺腺癌的动物通过尾静脉注射10 mg/kg的5-Se，并在注射5-Se后24小时用来自过滤钨灯的570 - 750 nm光、200 mW/cm²的光强照射720 J/cm²。治疗后的动物肿瘤倍增时间为9±4天，相对于未治疗的黑暗对照组的3±2天，肿瘤倍增时间增加了300%。从机制上讲，线粒体似乎是一个靶点。在用0.1和1.0 μM的5-Se和光处理的培养R3230AC大鼠乳腺腺癌细胞中，相对于未处理细胞中的细胞色素c氧化酶活性，线粒体细胞色素c氧化酶活性受到抑制。用10 μM染料5-Se处理的分离线粒体悬浮液经照射后抑制了细胞色素c氧化酶活性。在低氧环境中，酶抑制程度减弱。终浓度为30 U的超氧化物歧化酶并未改变染料5-Se对线粒体细胞色素c氧化酶的光致敏抑制作用。数据表明单线态氧可能在光致敏抑制线粒体细胞色素c氧化酶中起主要作用。
