Covering: July 2003 to June 2004. Previous review: Nat. Prod. Rep., 2004, 21, 625.

This review covers the isolation, structure determination, synthesis, chemical transformations and biological activity of indolizidine and quinolizidine alkaloids from microbial, plant and animal sources. Included in the review are the hydroxylated indolizidines lentiginosine, swainsonine, castanospermine and their analogues; alkaloids from animal sources, including ants, amphibians and beetles; indolizidine alkaloids from the genera Polygonatum and Prosopis; ipalbidine, septicine and related phenanthroindolizidine and phenanthroquinolizidine alkaloids; epimyrtine and the lasubines; Nuphar alkaloids; lupine alkaloids; and alkaloids from marine sources. The literature from July 2003 to June 2004 is reviewed, and 163 references are cited.