Between 1981-2006, about 100 anticancer
agents have been developed, 25% of
them were natural product derivatives, 18%
were natural product mimics, 11% candidates
were derived from a natural product
pharmacophore, and 9% were pure natural
products. Actually 47% of total anticancer
drugs and 52% of new chemicals introduced
into the market are of natural origin (Chin et al.
2006, Newman & Cragg 2007). In the USA
more than 50% of prescribed drugs are natural
products or semi-synthetic derivatives. In addition,
a number of chemicals used in crop protection
are also of natural origin (Schneider et al.
2008). Thus natural sources make a very significant
contribution to the health care) Fig.1