Heavy metal accumulation and chemical composition of essential oils of salvia officinalis cultivated on heavy metal contaminated soils

Comparative research has been conducted to allow us to determine the content of heavy metals and chemical composition of Salvia officinalis L oils, as well as to identify the possibility of Salviaofficinalis L. growth on soils contaminated by heavy metals. The experimental plots were situated atdifferent distances of 0.5 km and 15 km, respectively, from the source of pollution the Non-Ferrous-Metal Works (MFMW) near Plovdiv, Bulgaria. On reaching flowering stage the Salvia officinalis L plantswere gathered. The content of heavy metals in different parts of Salvia officinalis L. (roots, stems, leavesand inflorescences) was determined by ICP. The essential oil of the Salvia officinalis L. was obtainedby steam distillation in laboratory conditions which was analyzed for heavy metals and its chemicalcomposition was determined.Salvia officinalis L. is a plant which is tolerant to heavy metals and can be grown on contaminated soils.Favorable is also the fact that heavy metals do not influence the development of the Salvia officinalisL. as well as on the quality and quantity of the essential oil. Twenty-nine components were identifiedin the oil. The main compounds of essential oi were as follows: α-thujone (15.927-18.912), camphor(16.839-17.826), trans-thujone (5.379-11.575), 1,8-cineole (6.891-7.625), camphene (6.024-6.514), α-humulene (5.395-6.098), borneol (4.591-5.394), (e)-β-caryophyllene (3.868-4.576), limonene (3.458-4.612),bornyl acetate (1.621-3.194), viridiflorene (2.449-5.633), β-pinene (2.174-2.223), allo-aromadendrene(2.034-4.777). The compounds in the essential oil that decreased as a result of heavy metals pollutionare limonene, bornyl acetate and allo-aromadendrene, while the α-thujone, trans-thujone, camphorand viridiflorene significantly increased. Observed increase of the levels of α-thujone, trans-thujone,and camphor level in the leaves of sage grown on heavy metals polluted soil indicated an improvementof the essential oil quality. The essential oil of Salvia officinalis L. can be a valuable product for thefarmers from the polluted regions.