Abstract
Glycyrrhetinic Acid (GA), a triterpenoid aglycone component of the natural product glycyrrhizinic acid, was found to possess remarkable anti-proliferative and apoptosis-inducing activity in various cancer cell lines. Though GA was not as active as other triterpenes, such as betulinic acid and oleanolic acid, it could trigger apoptosis in tumor cells and it can be obtained easily and cheaply, which has stimulated scientific interest in using GA as a scaffold to synthesize new antitumor agents. The structural modifications of GA reported in recent decades can be divided into four groups, which include structural modifications on ring-A, ring-C, ring-E and multiple ring modifications. The lack of a comprehensive and recent review on this topic prompted us to gather more new information. This overview is dedicated to summarizing and updating the structural modification of GA to improve its antitumor activity published between 2005 and 2016. We reviewed a total of 210 GA derivatives that we encountered and compiled the most active GA derivatives along with their activity profile in different series. Furthermore, the structure activity relationships of these derivatives are briefly discussed. The included information is expected to be of benefit to further studies of structural modifications of GA to enhance its antitumor activity.
Highlights
Natural products have played a highly significant role in the medicine discovery and development processes and many useful medicines were developed from plant sources [1]
A, C, and rings, as these three rings contain three functional groups which are the most suitable for modification: a hydroxyl three rings contain three functional groups which are the most suitable for modification: a hydroxyl group at C-3 in ring-A, an α,β-unsaturated carbonyl function located in ring-C at C-11 and a carboxyl group inon ring-A, anMeanwhile, α,β-unsaturated carbonyl in ring-C at modification
These derivatives showed a higher antitumor activity and a better selectivity towards tumor cells compared with glycyrrhetinic acid (GA) on 15 different human tumor cell lines and mouse embryonic fibroblasts
Summary
Natural products have played a highly significant role in the medicine discovery and development processes and many useful medicines were developed from plant sources [1]. GA is highly regarded for its remarkable antitumor activities, whereby it shows significant cytotoxic activity against a broad variety of different cell types in vitro, for example non-small cell lung cancer cells [11], pituitary adenoma cells [12], human hepatocellular carcinoma cells [13], prostate cancer cells [14] and glioblastoma cells [15] It exhibits noteworthy activity in various experimental cancer models in vivo [16,17], and it is known to trigger apoptosis in tumor cell lines [14,18,19].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
