Evaluation of flavonols and derivatives as human cathepsin B inhibitor

Nat Prod Res. 2015;29(23):2212-4. doi: 10.1080/14786419.2014.1002404. Epub 2015 Jan 27.


Cathepsin B (catB) is a cysteine protease involved in tumour progression and represents a potential therapeutic target in cancer. Among the 15 evaluated extracts from cerrado biome, Myrcia lingua Berg. (Myrtaceae) extract demonstrated to be a source of compounds with potential to inhibit catB. Using bioactivity-guided fractionation, we have found flavonols as inhibitors and also some other derivatives were obtained. From the evaluated compounds, myricetin (5) and quercetin (6) showed the most promising results with IC50 of 4.9 and 8.2 μM, respectively, and mode of inhibition as uncompetitive on catB. The results demonstrated polyhydroxylated flavonols as promising inhibitors of catB.

Keywords: cathepsin B; flavonoids; uncompetitive inhibitor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cathepsin B / antagonists & inhibitors*
  • Flavonoids / chemistry
  • Flavonols / chemistry*
  • Humans
  • Inhibitory Concentration 50
  • Myrica / chemistry*
  • Plant Extracts / chemistry*
  • Quercetin / chemistry


  • Flavonoids
  • Flavonols
  • Plant Extracts
  • myricetin
  • Quercetin
  • Cathepsin B