Covering: 2005 to 2007. Previous review: Nat. Prod. Rep., 2005, 22, 516.

Organic guanidine compounds are reviewed, with emphasis on natural products isolation, identification, synthesis and biological activities. The literature survey includes purely synthetic guanidine derivatives, guanidine alkaloids and non-ribosomal peptides from bacteria and cyanobacteria, as well as related compounds isolated from marine and terrestrial invertebrates and higher plants.