Covering: July 2010 to June 2012. Previous review: Nat. Prod. Rep., 2011, 28, 1143–1191.

Structurally diverse alkaloids containing five-membered heterocyclic subunits, such as imidazole, oxazole, thiazole, as well as their saturated congeners, are widely distributed in terrestrial and marine organisms and microorganisms. These naturally occurring secondary metabolites often exhibit extensive and pharmacologically important biological activities. The latest progress involving isolation, biological activities, chemical synthetic studies, and biosynthetic pathways of these natural products has been summarized in this review.