A new bisbenzylisoquinoline alkaloid from Plumulanelumbinis

One new bisbenzylisoquinoline alkaloid, neferine N-oxide (1), along with three known compounds, neferine (2), liensinine (3), and isoliensinine (4), were isolated from Plumulanelumbinis-the embryo of the seed of Nelumbonucifera. Their structures were elucidated by extensive spectroscopic analysis (MS, UV, IR, NMR), and the absolute configurations were determined by experimental circulardichroism (CD) spectra. Compound 1 is a new naturally occurring bisbenzylisoquinoline alkaloid with an N-oxide functionality, and the CD spectrum of (1R, 1'R) neferine is first reported. The antioxidant activities of compounds 1-4 were evaluated using the ORAC assay, which illustrated that all these compounds showed the different levels of oxygen radical absorbance capacity.