Melissa officinalis L. subsp. altissima (Sibth. & Sm.) Arcang. essential oil: Chemical composition and preliminary antimicrobial investigation of samples obtained at different harvesting periods and by fractionated extractions

A comprehensive study on essential oils extracted from different samples of Melissa officinalis L. subsp. altissima (Sibth. & Sm.) Arcang. (Lamiaceae) collected in Tarquinia (Italy) is reported. In this study, the 24-h steam distillation procedure for essential oil preparation, in terms of different harvesting periods and extraction times was applied. The GC/MS analysis showed cis-caryophyllene and its oxide as the major essential oil's constituents. A great impact of phenological stage on chemical profile of essential oil was observed. Regarding the duration of the extraction process, prolonged distillation led to chemically more diverse oil samples. Preliminary microbiological evaluations of the essential oils samples revealed the lack of significant efficacy against Candida albicans.