New Acidic-Rearranged Compounds from Tingenone Derivatives and their Biological Activity

Abstract

Quinone-methide triterpenes of the tingenone series are effective cytotoxic and antimicrobial agents. Under an acidic condition, they can rearrange to the phenolic analogues. In the current study, six new compounds (7–12) along with three known products (4–6) were obtained from the acid-rearranged reaction of tingenone derivatives (1–3). Their structures were determined on the basis of spectroscopic evidence. Antiviral and antimicrobial activities of all compounds were evaluated. Data associated to their structures were suggested. The quinone-methide chromophore at rings A/B was necessary for antimicrobial activity. The acid-rearranged phenolic analogues were less toxic but lost antimicrobial potential. However, compounds with the phenolic ring conjugated to two vinyl groups (compounds 4–6) had an inhibitory effect on Herpes simplex virus with a selective index greater than 5.

Keywords:

• Acid-rearrangement reaction
• antiviral activity
• Herpes simplex virus
• quinone-methide triterpenes
• tingenone