A Chemical and Microscopical Study of Different Parts of Echinops polyceras Boiss. and Determination of Volatile Oil Composition

Abstract

Background & Aim: Syria is rich in medicinal plants including the species of the genus Echinops, due to its geographical location. The chemical composition of many species of this genus was studied and it showed that they contain flavonoids, thiophenes, terpenoids, alkaloids, and essential oils, and most of them have biological effects. Neither the chemical composition of Echinops polyceras Boiss., nor the volatile oil, nor the microscopic elements have been studied previously. So, our research aimed to study this species chemically and microscopically.

Materials & Methods: The plant has collected from Maarrat Saydnaya, and it has dried and divided into three parts: flowering heads, leaves, and roots, then microscopic elements of each part were determined. After that, secondary metabolites detection reactions were performed. The essential oil was obtained, and its chemical composition was analyzed using GC-MS.

Results: Identification reactions showed that the three parts contain phenolic compounds including flavonoids and coumarin. However, tannins, anthraquinones, alkaloids, and cardiac glycosides have not existed. The volatile oil analysis results have shown that the yield was 0.1%, and 32 aromatic compounds were identified, most of which are mono and sesquiterpenes. Ar-turmerone was the most abundant compound at approximately 64%. Also, in the microscopic study, the microscopic elements were identified in flower heads (pollen and unicellular aggregated fibers), leaves (irregular pattern pores and dense trichomes), and roots (sclerotic fibers and cells).

Conclusions: This research is the first study on E. polyceras, where a preliminary identification of the secondary metabolites was determined, as well as the chemical composition of the volatile oil. Also, the microscopic elements of each part were determined. Phenolic compounds such as flavonoids and coumarins, were identified, so, we can expect that the plant extracts have antioxidant properties. Ar-turmerone -which was firstly identified in Echinops genus species- was the main component in the volatile oil.