Cassuto E, Carter D M
J Invest Dermatol. 1979 Sep;73(3):236-8. doi: 10.1111/1523-1747.ep12514302.
Two medically useful photosensitizing furocoumarins, 8-methoxypsoralen (8-MOP) and 4,5'8-trimethylpsoralen (TMP) were compared with respect to their abilities to produce interstrand crosslinks in DNA. DNA from bacteriophage lambda, labeled with 32P, was subjected to sedimentation in alkaline sucrose gradients following exposure to several concentrations of 1 of the 2 psoralens and irradiation (UV-A, 360 nm) for various times. In alkaline sucrose gradients, crosslinked DNA molecules sediment about 1.4 times faster than undamaged DNA strands and the proportion of molecules carrying crosslinks can be estimated with reasonable accuracy. At equimolar psoralen concentrations (2 x 10(-7)M, or 4 x 10(-5)M) and with increasing irradiation times, the rate of production of crosslinked DNA was 4 to 30 times greater for TMP than for 8-MOP. Differences in the therqpeutic efficacy of 8-MOP and TMP in various clinical situations may be accounted for by the types of photoadducts formed by each drug as well as by their solubilities, rates of absorption and rates of metabolic degradation.
对两种具有医学用途的光敏性呋喃香豆素，即8-甲氧基补骨脂素（8-MOP）和4,5',8-三甲基补骨脂素（TMP），就它们在DNA中产生链间交联的能力进行了比较。用32P标记的噬菌体λDNA，在分别暴露于两种补骨脂素之一的几种浓度并进行不同时间的紫外线A（UV-A，360纳米）照射后，在碱性蔗糖梯度中进行沉降。在碱性蔗糖梯度中，交联的DNA分子沉降速度比未受损的DNA链快约1.4倍，并且携带交联的分子比例可以相当准确地估算出来。在补骨脂素等摩尔浓度（2×10−7M或4×10−5M）且照射时间增加的情况下，TMP产生交联DNA的速率比8-MOP高4至30倍。8-MOP和TMP在各种临床情况下治疗效果的差异，可能是由每种药物形成的光加合物类型以及它们的溶解度、吸收速率和代谢降解速率所导致的。
