Bioactive compounds from Okinawan marine cyanobacteria

Natural products, especially those from terrestrial plants and microbes, have been the most productive source of drug molecules over the years, and pharmacologically active compounds from plants and microbes continue to play an important role in developing new investigational drugs (Butler 2008; Newman and Cragg 2007). However, much attention has recently been given to marine organisms due to their remarkable biological activities (Molinski et al. 2009). In particular, cyanobacteria are prolific producers of biologically active compounds (Gerwick, Tan, and Sitachitta 2001). Cyanobacteria have been recognized as a source of pharmaceutical lead compounds (Tan 2007), for example, TZT-1027, a synthetic dolastatin 10 analog, is currently being evaluated in phase II clinical trials in the United States (Yamamoto et al. 2009). Dolastatin 10 was originally isolated from the sea hare Dolabella auricularia and has been subsequently isolated from marine cyanobacterium (Luesch et al. 2001; Pettit et al. 1987). Cryptophycin-309 and cryptophycin-249, which are derivatives of the terrestrial cyanobacterial peptide cryptophycin-1, have undergone preclinical efficacy studies (Liang et al. 2005).