Underberg W J, Beijnen J H
Department of Pharmaceutical Analysis, Faculty of Pharmacy, Utrecht University, The Netherlands.
Pharm World Sci. 1993 Jun 18;15(3):123-7. doi: 10.1007/BF02113940.
The acid-catalyzed degradation of mitomycin C is supposed to be governed, to a certain extent, by the protonation status of the aziridine nitrogen in the molecule as well as the protonation degree of the opened aziridine function in a key intermediate species, formed during mitomycin degradation. In order to obtain information about the contribution of the protonation degrees of these functions in controlling the degradation processes, we investigated the degradation of 1a-acetylmitomycin C in acidic aqueous solutions. In the presence of 0.001 mol/l phosphate buffers five 1-hydroxy and mono-acetyl mitosenes are formed, whereas in 1.0 mol/l acetate buffers a total of eight products could be identified, two of them being diacetyl mitosenes. Over the whole pH range studied the formation of 1,2-Z-mitosenes prevails, indicating that, contrary to mitomycin C, a pH-independent factor controls the ultimate 1,2-stereochemistry.
丝裂霉素C的酸催化降解在一定程度上被认为受分子中氮丙啶氮的质子化状态以及丝裂霉素降解过程中形成的关键中间物种中开环氮丙啶官能团的质子化程度的支配。为了获取有关这些官能团的质子化程度在控制降解过程中所起作用的信息，我们研究了1a-乙酰丝裂霉素C在酸性水溶液中的降解。在0.001 mol/l磷酸盐缓冲液存在下，形成了5种1-羟基和单乙酰丝裂霉素烯，而在1.0 mol/l乙酸盐缓冲液中总共可鉴定出8种产物，其中两种是二乙酰丝裂霉素烯。在所研究的整个pH范围内，1,2-Z-丝裂霉素烯的形成占主导，这表明与丝裂霉素C相反，一个与pH无关的因素控制着最终的1,2-立体化学。
