Betel leaf essential oil – Phenolic content and influence on biological activities

Abstract

      The main phenolic constituents of Hoc Mon betel leaf essential oil were identified by us as chavibetol 1, chavibetol acetate 2 and 4-allylpyrocatechol diacetate 3 (APC diacetate). Chavibetol percentage as well as total phenolic content including compounds 1, 2, 3 strongly influenced on the oil’s microbial and antioxidant activities, particularly on its ability to neutralize EV 71 causing Hand, Foot and Mouth disease discovered for the first time by us in 2012. Also for the first time in 2011, on hydrodistillation of betel leaves in unsalted water, we observed the conversion of 2 and 3 into 1 through enzymatic reactions leading to a drastic decrease of oil yield and of total phenolic content. In this communication, the experimental conditions allowing to obtain good oil yield and high phenolic content or oil with high chavibetol content were defined. Also antimicrobial activities, in particular the ability of EV 71 neutralization of betel oil in function of its total phenolic content and the antioxidant property in function of its chavibetol content were evaluated.