Volatile Composition and Biological Activities of the Leaf Essential Oil from Zanthoxylum limoncello Grown in Oaxaca, México

Abstract

Zanthoxylum limoncello is a native plant from southern Mexico which is used as a timber source, condiment and as a traditional medicine. Herein, we report on the volatile content of the leaf essential oil and its biological activities. The annual essential oils (2015–2018) contained volatile organic compounds which exhibited a moderate growth inhibitory activity against H. pylori ATCC 53504 (MIC 121.4–139.7 μg mL −1 ), 26695 (MIC 85.5–94.9 μg mL −1 ) and J99 (MIC 94.7–110.4 μg mL −1 ). These hydrodistillates contained 2-undecanone (31.6–36.8 %; MIC 185.3–199.2 μg mL −1 ) and 2-undecenal (25.1–35.7 %; MIC 144.8–111.3 μg mL −1 ) as the most abundant compounds which were partially involved in the anti-H. pylori activity. The human ornithine decarboxylase enzyme (ODC1), which shows increased activity in several cancer types, was non-competitively inhibited (V max 2.7>0.8 K cat s −1 ) by the essential oil of Z. limoncello as well as by 2-undecanone and 2-undecenal in accordance to in vitro kinetic studies. In silico calculations strongly suggest that the carbonyl group of these oxygenated hydrocarbons interacts with both Asn319 and Ala39 at the subunit A of ODC1. Considering that Ala39 is located close to Asn44, a crucial amino acid of the ODC's allosteric site, the non-competitive inhibition of the enzyme by 2-undecanone and 2-undecenal is endorsed. Finally, the essential oil of Z. limoncello and its main volatiles showed a significant (p<0.01) and prolonged repellent effect against Aedes aegypti.