ChEMBL

There's a very accessible article (subscription required) on plant derived natural products in Science recently - this is in the context of understanding and exploiting the biosynthetic pathways to discover new natural products and then engineering new systems to make these or better variants of them; Synthetic Biology.

%A V. De Luca
%A V. Salim
%A S.M. Atsumi
%A F. Yu
%T Mining the biodiversity of plants: A revolution in the making
%J Science
%D 2012
%V 336
%P 1658-1661

Table 1 (itself adapted from I. Raskin et al., Trends Biotechnol. 20, 522 (2002)) is interesting and worthy of note (reproduced here without permission ;) ) and lists the most commercially important natural products, lots of 'toxins' in there (e.g. digoxin, taxol, atropine), and some goofy things that we wouldn't normally think of as therapeutic drugs (e.g. nicotine, cocaine). These have a net value of $25 bn per year (although it's unclear if that figure is US only, or how cocaine is 'valued'). They make the claim that 'two-thirds of new drugs in the past 25 years have originated from the discovery of particular secondary metabolites derived from natural biodiversity' - our analysis doesn't support anything like that number, unless the most rose-tinted spectacles are used in the analysis, however, it would be fascinating to see a properly presented case for this number. However, a great orientation to the exciting area of secondary metabolites, and a good pointer to a set of molecules that can successfully modulate 'difficult' targets.