Arglabin: From isolation to antitumor evaluation.

Arglabin belongs to guaianolide class of sesquiterpene lactones, isolated from Artemisia species. The molecule bears a 5,7,5-tricyclic ring system having five contiguous stereo centers in which the two five membered rings are trans-annulated. Arglabin shows promising antitumor activity against different tumor cell lines. The antitumor activity of arglabin proceeds through its inhibition of farnesyl transferase which leads to the activation of RAS proto-oncogene, a process that is believed to play a pivotal role in 20-30% of all human tumors. It actually inhibits the incorporation of farnesyl pyrophosphate into human H-ras proteins by the enzyme farnesyl transferase (FTase). The present review is an attempt to summarize the chemistry and biology of this molecule since its isolation in 1982. It embodies the isolation, structure elucidation, stereo chemical description, structural classification, chemical synthesis, structural modifications and antitumor evaluation reported till date.