DNA topoisomerases are important cellular enzymes found in almost all types of living cells
(eukaryotic and prokaryotic). These enzymes are essential for various DNA metabolic processes e.g.
replication, transcription, recombination, chromosomal decatenation etc. These enzymes are important
molecular drug targets and inhibitors of these enzymes are widely used as effective anticancer and antibacterial
drugs. However, topoisomerase inhibitors have some therapeutic limitations and they exert serious
side effects during cancer chemotherapy. Thus, development of novel anticancer topoisomerase
inhibitors is necessary for improving cancer chemotherapy. Nature serves as a repertoire of structurally
and chemically diverse molecules and in the recent years many DNA topoisomerase inhibitors have
been identified from natural sources. The present review discusses anticancer properties and therapeutic
importance of eighteen recently identified natural topoisomerase inhibitors (from the year 2009 to
2015). Structural characteristics of these novel inhibitors provide backbones for designing and developing
new anticancer drugs.