Chemical Characterization of Essential Oils With a Biocide Base for Conservation and Restoration

Essential oils (EOs) are acclaimed for their antimicrobial properties, leading to their multiple applications in various fields. In this work, four aromatic plants were used, namely thyme (Thymus mastichina L.), everlasting (Helychrysum stoechas Moench), European pennyroyal (Mentha pulegium L.) and fennel (Foeniculum vulgare Mill.). Hydrodistillation was the extraction method used, and the obtained extracts were composed of a variety of volatile molecules, mainly terpenoids and phenylpropenoids. The EO yields were determined, and the chemical composition of these natural products was obtained by gas chromatography-mass spectrometry (GC-MS) analysis. The yields varied greatly in the range of 0.99 to 4.27% (v/w). The two major chemical constituents of the EOs analysed by GC-MS were as follows: thyme – 1,8-cineole and champhor; everlasting – α-pinene and limonene; European pennyroyal – pulegone and isomenthone; fennel – trans-anethole and limonene. This preliminary study is an important contribution to the understanding of EO bioactive compounds that are under investigation to establish their ability to control the biocolonization of cultural heritage. Keywords: aromatic plants, chemical characterization, essential oils, green biocides