Fagaridine is a quaternary benzo[c]phenanthridine alkaloid, originally isolated from Fagara xanthoxyloides in 1973. The assigned structure of this alkaloid was 7-hydroxy-8-methoxy-5-methyl-2, 3-(methylenedioxy)benzo[c]phenanthridinium (1). We have synthesized this compound, coded NK109, aiming at a practical antitumor drug, and during synthetic studies we questioned the original assigned structure. Thus, we synthesized 8-hydroxy-7-methoxy-5-methyl-2, 3-(methylenedioxy)benzo[c]phenanthridinium (2), isomer of the assigned structure, and compared the spectroscopic data of both 1 and 2. The NMR data of 1 and 2 were very similar, but the UV spectra were completely different. The UV data for fagaridine agreed with these for 2; consequently, the true structure of fagaridine is 2, not 1.

中文翻译：

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根据合成化合物的UV和NMR数据比较，对法加替丁进行结构修改。

Fagaridine是季铵基苯并[c]菲啶生物碱，最初于1973年从Fagara黄蒽酮中分离出来。该生物碱的指定结构为7-羟基-8-甲氧基-5-甲基-2，3-（亚甲基二氧基）苯并[c]菲啶鎓（1）。我们已经合成了一种针对NK109的化合物，旨在开发一种实用的抗肿瘤药物，在合成研究过程中，我们对最初指定的结构提出了质疑。因此，我们合成了指定结构的异构体8-羟基-7-甲氧基-5-甲基-2、3-（亚甲基二氧基）苯并[c]菲啶鎓（2），并比较了1和2的光谱数据。 1和2的NMR数据非常相似，但UV光谱完全不同。法加替丁的UV数据与2的一致。因此，法加替丁的真实结构是2，而不是1。