The structures of chelirubine and chelilutine free bases have been examined by 2D NMR spectroscopy and mass spectrometry. Chelirubine chloride (1a) upon treatment with Na2CO3 yielded free base which possessed the constitution of bis(5,6-dihydrochelirubin-6-yl) ether (2a). The free base of chelilutine (1b) was determined to be bis(5,6-dihydrochelilutin-6-yl) ether (2b). The aqueous NH3 treatment of chelilutine (1b) produced bis(5,6-dihydrochelilutin-6-yl)amine (3b). 6-Hydroxy-5,6-dihydrochelirubine (4a) and 6-hydroxy-5,6-dihydrochelilutine (4b) were detected only in CDCl3 solution by NMR spectroscopy. In CDCl3, the compound 2b underwent hydrolysis to 4b that was immediately followed by the reverse condensation to a diastereomer of 2b. Pseudokinetics of this reaction was followed by NMR spectroscopy and quantum chemical calculations were carried out to support the suggested type of molecular symmetry alteration. The known alkaloid dihydrochelirubine (5) was isolated for the first time from Sanguinaria canadensis.
自由碱的结构已通过2D NMR光谱和质谱进行了检查。氯化钡鲁宾(1a)经Na2CO3处理后产生的自由碱具有双(5,6-二氢鲁宾-6-基)醚(2a)的构成。鲁宾碱(1b)的自由碱被确定为双(5,6-二氢鲁宾碱-6-基)醚(2b)。鲁宾碱(1b)的水溶性NH3处理产生了双(5,6-二氢鲁宾碱-6-基)胺(3b)。6-羟基-5,6-二氢鲁宾(4a)和6-羟基-5,6-二氢鲁宾碱(4b)只在CDCl3溶液中通过NMR光谱检测到。在CDCl3中,化合物2b经水解生成4b,紧接着发生了反向缩合形成2b的对映异构体。通过NMR光谱跟踪了该反应的伪动力学,并进行了量子化学计算以支持所建议的分子对称性改变类型。已知生物碱二氢鲁宾(5)首次从加拿大血根中分离出来。