Table 1.

Newman and Cragg codes.

Code	Brief definition/review year
B	biological macromolecule/1997
N	unaltered natural product/1997
NB	botanical drug (defined mixture)/2012
ND	natural product derivative/1997
S	synthetic drug/1997
S*	synthetic drug (NP pharmacophore)/1997
V	vaccine/2003
/NM	mimic of natural product/2003