Arnason J T, Guèrin B, Kraml M M, Mehta B, Redmond R W, Scaiano J C
Ottawa Carleton Biology Institute, University of Ottawa Campus, Ontario, Canada.
Photochem Photobiol. 1992 Jan;55(1):35-8. doi: 10.1111/j.1751-1097.1992.tb04206.x.
Sanguinarine, a commercial drug exhibiting antimicrobial and antitumor properties, was studied with respect to its basic photochemical characteristics and also with regard to its phototoxicity to mosquito larvae (Aedes atropalpus). Sanguinarine proved to be clearly phototoxic to larvae, with an LD50 of 0.096 mg/mL with near UV exposure as compared with 23.3 mg/mL without. Flash photolysis experiments enabled the study of the triplet state of sanguinarine to be undertaken. Quenching by oxygen occurs with a rate constant of 6 x 10(9) M-1s-1 and time-resolved emission studies indicate that sanguinarine produces a significant amount of singlet oxygen (phi delta = 0.16) as does the isoquinoline alkaloid, berberine (phi delta = 0.25). These values represent the first direct quantitative measurements of photosensitization parameters of these compounds. Additionally, sanguinarine exhibits efficient electron donation properties, undergoing reaction with methyl viologen with a rate constant greater than 10(10) M-1s-1, but is a poor electron acceptor. Phototoxicity of sanguinarine can thus be explained in terms of its photosensitization properties.
血根碱是一种具有抗菌和抗肿瘤特性的商业药物，对其基本光化学特性以及对蚊幼虫（致倦库蚊）的光毒性进行了研究。结果证明血根碱对幼虫具有明显的光毒性，近紫外光照射下的半数致死剂量（LD50）为0.096毫克/毫升，而无光照时为23.3毫克/毫升。闪光光解实验使得对血根碱三重态的研究得以开展。氧猝灭的速率常数为6×10⁹ M⁻¹s⁻¹，时间分辨发射研究表明，血根碱与异喹啉生物碱小檗碱一样，能产生大量单线态氧（φδ = 0.16，小檗碱的φδ = 0.25）。这些数值代表了对这些化合物光敏化参数的首次直接定量测量。此外，血根碱表现出高效的电子供体性质，与甲基紫精反应的速率常数大于10¹⁰ M⁻¹s⁻¹，但却是较差的电子受体。因此，血根碱的光毒性可以用其光敏化性质来解释。
