Chapter 1 Ipecac Alkaloids and β-Carboline Congeners

Two Alangium Alkaloids from Alangium lamarckii

“…Alangium lamarckii Thwaites (Alangiaceae) is a deciduous shrub of wide distribution in India and South East Asia. The root, root-bark, and bark of this plant have been used in the indigenous Indian systems of medicine for a long time . Previous phytochemical studies of A. lamarckii resulted in the isolation of numerous classes of alkaloids, i.e., emetan, tubulosan, 3-ethyl-2 H -benzo[ a ]quinolizine (protoemetinol), and 8 H -isoquino[2,1- b ][2,7]naphthyridine-8-one (alangimaridine) .…”

“…The root, root-bark, and bark of this plant have been used in the indigenous Indian systems of medicine for a long time . Previous phytochemical studies of A. lamarckii resulted in the isolation of numerous classes of alkaloids, i.e., emetan, tubulosan, 3-ethyl-2 H -benzo[ a ]quinolizine (protoemetinol), and 8 H -isoquino[2,1- b ][2,7]naphthyridine-8-one (alangimaridine) . Recently, several new nitrogenous glycosides closely related to the Alangium alkaloids were isolated from the fruits of this plant. − We have reexamined the alkaloidal fraction of the fruits of A. lamarckii and report here the isolation and characterization of two additional novel Alangium alkaloids ( 1 and 2 ).…”

Rubiaceae Juss.

“…Leaves simple; opposite or whorled; venation pinnate or a single vein; stipules leafl ike or triangular, or sheathing and bristly, free or fused to petioles. These alkaloids, in addition to their emetic activity, have a wide range of effects on other organs, including the heart (Gibbs 1974;Fujii and Ohba 1983). Flowers perfect; perianths in 1 -series or 2 -series.…”

Biogenetic Conversion of Tetrahydroisoquinoline−Monoterpene Glucosides into Benzopyridoquinolizine Alkaloids of Alangium lamarckii

“…Alangimaridine ( 1 ), alangimarine ( 2 ), and isoalangimarine ( 3 ) are unique benzo[ a ]pyrido[3,4- g ]quinolizine alkaloids isolated from Alangium lamarckii Thwaites (Alangiaceae), a medicinal plant used in Indian folk medicine in the treatment of various diseases. , The previous phytochemical studies demonstrated that these alkaloids coexist in the plant along with ipecac alkaloids, represented by emetine ( 4 ) and cephaeline ( 5 ), and a nitrogenous glucoside, alangiside ( 6 ) ( 1 ) is the same as that of alangiside ( 6 ) but different from the stereochemistry at the corresponding chiral center of emetine ( 4 ).…”