Biological Efficacy of Carvacrol Analogues.

Background: Carvacrol is the major constituent of essential oils derived from plants. It exhibits antimicrobial, antioxidant, anticancer, anti-inflammatory, and anticholinesterase activity. The analogues of carvacrol can be prepared via selected synthetic routes, resulting in potent compounds.

Objective: Modifying carvacrol by the introduction of selected functionalities has the potential to enhance the biological activity of carvacrol. The functionalities on carvacrol such as the hydroxyl group, benzene ring and alkyl groups can be modified or used for hybridization with important pharmaceutical scaffolds.

Results: In one of the patents cited, EP1053744B1, the modification of the hydroxyl group and the introduction of allyl groups into the benzene ring resulted in carvacrol analogues with antibacterial activity. Modifying the hydroxyl group influenced the hydrophobicity of the analogues and the size of the ring substituent. The hydrophobicity and the size of the ring substituent influence the analogues interactions with bacterial cells. The analogues of carvacrol with anticancer activity were influenced by the position of the substituted groups on the benzene ring. Substituent introduced at the ortho and para- positions resulted in better antitumor activity when compared to the ones with substituents on the meta-position.

Conclusion: Based on several reports on cavarcrol analogues, more research on the development of carvacrol analogues will result in potent compounds that can overcome drug resistance which is currently a challenge in the treatment of diseases, such as bacterial infections, cancer, fungal infections etc. However, more biological evaluation is required in order to fully understand the mode of action of these analogues on selected pathogens.