Two new carbazole alkaloids from Murraya koenigii.

Two new carbazole alkaloids named murrayanine (1) and 8,8' '-biskoenigine (2) were isolated from Murraya koenigii. The structure elucidations for 1 and 2 were carried out on the basis of 1D and 2D NMR experiments. Compound 1 was a novel carbazole alkaloid with a rare phenylpropanyl substitution. Compound 2 was a symmetrical dimer of the carbazole alkaloid koenigine and showed antiosteoporotic activity in the CAT-B model with IC(50) 1.3 microg/mL. The synthesis of 2 from koenigine was carried out through oxidative coupling using a solid state reaction.