Alkaloids and phenylpropanoids from Peganum nigellastrum

Two canthin-6-one alkaloids, luotonins C and D, and two phenylpropanoids, dihydrosinapyl ferulate and dihydroconiferyl ferulate, were isolated from the aerial parts of Peganum nigellastrum along with four known alkaloids, harmine, 3-phenylquinoline, 3-(4-hydroxyphenyl)quinoline and 3-(1H-indol-3-yl)quinoline. Their structures were elucidated by spectroscopic techniques. The structures of luotonins C and D were also confirmed by chemical synthesis.