Piper multinodum C.DC. (Piperaceae) essential oils chemical variation and biological activity against Mycobacterium tuberculosis

Abstract

Piper multinodum C.DC. belongs to the Piperaceae family, and is known as "Jaborandi-manso". This species has no reported botanical, chemical, pharmacological and/or toxicological scientific studies, and has restricted occurrence in degraded Brazilian biomes. The Piper genus is known to be aromatic, the essential oils (EO) obtained from different organs have demonstrated significant biological activities, and can be an important tool for chemophenetic and ecological definitions. The present study aimed to characterize the chemical profile of the EO from different parts of P. multinodum and their activity against Mycobacterium tuberculosis H 37 Rv (ATCC, 25618). The EO were obtained by hydrodistillation and characterized by GC-MS and GC-FID. Chemical composition of the volatile mixture showed a great diversity of compounds that diverged between the vegetative and reproductive parts. The α-pinene compound was identified as being the most predominant in the leaves, infructescences and inflorescences (32.49, 67.23 and 40.23%, respectively). The branches (secondary stem) showed to be rich in sesquiterpenes and monoterpenes: α-copaene (13.24%), E-caryophyllene (12.32%), α-pinene (20.34%), and myrcene (11.23%). The chemical profile of stems and roots showed a low percentage of monoterpenes and sesquiterpenes, but a high percentage of arylpropanoids, with E-methyl-isoeugenol (77.58%) registered in the stems and euasarone (81.34%) in the root. The antimycobacterial activity showed the highest activities recorded for the EO from roots (78.51 µg/mL) and infructescences (85.91 µg/mL). In addition to the findings related to biological activity, the determination of chemical diversification between the different parts of P. multinodum may help to understand the ecological issues of the Piperaceae family as well as to improve the chemotaxonomic knowledge of the genus Piper.