In order to better understand the mechanism by which taxol operates and
hence find possible analogues of taxol, such as DocetaxelŽ,
that have the same anticancer properties but which might prove easier to synthesise, a
number of structure activity relationships have been studied by many different
researchers. The results of these studies are summarised below:
The molecule taxol.
The structure of taxol, for ease of analysis, can be divided into two parts; the taxol skeleton and the side
chain. . In the following paragraphs the structure of these two
parts is described in detail and the effects that each functional group has on taxol's
activity is discussed.
1. The Taxol Skeleton
Many people have studied the main skeleton of taxol. The taxol backbone
consists of an eight membered ring , a six membered ring and a four
membered ring . Attached to these rings are several functional groups
including and OH group, two benzoyl groups, an acetyl group and an oxetane ring.
Modification of the taxol skeleton followed by analysis of the resulting molecules
structure have resulted in the following findings concerning the 4-10-6 skeleton of taxol:
2. The Side Chain
The structure and activity of the side chain of taxol has been studied in depth
by Potier7 and Swindell8. Their research showed that the side
chain is critical for maintaining taxol's activity. Their work revealed the
following properties of the side chain:
A greater knowledge of the mechanism by which taxol operates and what
parts of it's structure are essential to maintaining the anti cancer activity have
provided scientists with the information necessary to prepare simpler alternatives while
still maintaining the anti cancer properties of the taxol molecule.