Berenbaum M C, Bonnett R, Scourides P A
Br J Cancer. 1982 Apr;45(4):571-81. doi: 10.1038/bjc.1982.94.
The in vivo biological activity of various fractions and components of haematoporphyrin derivative (HpD) have been determined by measuring the depth of necrosis of implanted tumours in mice exposed to light after the administration of standard doses of porphyrins dissolved in alkali. In this assay, haematoporphyrin, hydroxyethylvinyldeuteroporphyrin and protoporphyrin are inactive, but the mono- and di-acetates of haematoporphyrin (which are major components of HpD) and acetoxyethylvinyldeuteroporphyrin are active. However, the situation appears to be more complex than this. The normal method for preparing HpD for injection involves an alkali treatment which causes hydrolysis and elimination of the acetoxy functions, and the only recognized products (haematoporphyrin, hydroxyethylvinyldeuteroporphyrin and protoporphyrin) are inactive in the in vivo assay. It is concluded that the active component here is a porphyrin, possibly a dimer or oligomer, which is retained on the column during the normal separation by HPLC. This conclusion is supported by the observations that (i) the crude material obtained from the spent column is active without further alkali treatment, and (ii) activity develops over 30 min, when HpD or the mono- or diacetates of haematoporphyrin are treated with sodium bicarbonate in aqueous DMSO. The advantages of working with a pure substance (e.g. haematoporphyrin diacetate) rather than a mixture (HpD) are stressed.
通过测量在给予溶解于碱中的标准剂量卟啉后经光照的小鼠体内植入肿瘤的坏死深度，已确定了血卟啉衍生物（HpD）各种级分和组分的体内生物活性。在该测定中，血卟啉、羟乙基乙烯基次卟啉和原卟啉无活性，但血卟啉的单乙酸酯和二乙酸酯（它们是HpD的主要组分）以及乙酰氧基乙基乙烯基次卟啉有活性。然而，情况似乎比这更复杂。用于注射的HpD的常规制备方法涉及碱处理，这会导致乙酰氧基功能的水解和消除，并且唯一公认的产物（血卟啉、羟乙基乙烯基次卟啉和原卟啉）在体内测定中无活性。得出的结论是，这里的活性成分是一种卟啉，可能是二聚体或寡聚体，其在通过高效液相色谱（HPLC）进行的常规分离过程中保留在柱上。这一结论得到以下观察结果的支持：（i）从用过的柱中获得的粗材料未经进一步碱处理即有活性，以及（ii）当HpD或血卟啉的单乙酸酯或二乙酸酯在二甲基亚砜水溶液中用碳酸氢钠处理时，活性在30分钟内显现。强调了使用纯物质（例如血卟啉二乙酸酯）而非混合物（HpD）进行研究的优点。
