Chemical composition of the essential oil from aerial parts of Micromeria fruticulosa (Bertol.) Grande (Lamiaceae) growing wild in Southern Italy

Abstract

Micromeria is a genus of fragrant plants which comprises Mediterranean perennial sub shrubs or herbs or chamaephytes common in open habitats and in rocky coasts. Several extracts from these plants are used in folk medicine against heart disorders, headache, wound skin infections and as antispasmodic, stimulant and expectorant [1, 2]. The extracts of some Micromeria sp. exhibited significant antibacterial activity [3]. Micromeria fruticulosa (Bertol.) Grande is a suffruticous plant 8–15cm tall, endemic of Campania and Sicily (Southern Italy) where it is locally named issopo marittimo. The isolation of the flavonoids naringenin and neoponcirin in this plant was previously reported [4]. Here for the first time, we report on the essential oil composition of the aerial parts of M. fruticulosa collected at the full flowering stage from plants wild growing on the Lattari mountains, Sorrento (NA, Southern Italy) in July 2005. The oil was isolated by hydrodistillation [5] and analyzed with GC and GC/MS. 64 constituents, representing 91.7% of the total oil have been identified. Monoterpenes (43.3%), almost entirely hydrocarbons, predominate over sesquiterpenes (31.0%). γ-Terpinene (14.5%), β-caryophyllene (12.6%), p-cymene (8.9%), α-pinene (8.2%) and β-bisabolene (7.2%) were the main components. The phenolic compounds amounted to 5.9% with carvacrol (5.3%) as the major one. The presence in this essential oil of compounds with known biological activity such as α-pinene, γ-terpinene and p-cymene [6] could account for the use of Micromeria in folk medicine.