Search

Ocimum basilicum L. exhibits a great variety of cultivars grown for various purposes. The aim of this research was to analyse the chemical composition of 85 O. basilicum accessions cultivated throughout the world using gas chromatography (GC/FID and GC/MS). All accessions were previously categorized into six morphotypes based on 24 morphological traits: True basil, Small-leaf, Lettuce-leaf, Purple basil A, Purple basil B and Purple basil C morphotype. A total of 77 volatiles were observed, with seven of them being in concentrations higher than 10% in at least one accession (1,8-cineole, linalool, linalool acetate, methyl chavicol, eugenol, trans-methyl cinnamate, trans-α-bergamotene). Based on the essential oil composition of 85 O. basilicum accessions, we propose the intraspecific characterization of O. basilicum into five chemotypes: (A) High-linalool, (B) Linalool/trans-α-bergamotene, (C) Linalool/methyl chavicol, (D) Linalool/trans-methyl cinnamate and (E) High-methyl chavicol chemotype. Groups based on morphological and biochemical traits do not necessarily coincide with one another. Due to great morphological and biochemical diversity, both morphological and chemical characterizations are crucial for the effective management of germplasm collections to facilitate the use of the accessions in future breeding programs.

The mixture of six components (pyrethrin I and II, cinerin I and II, and jasmolin I and II) constituting natural insecticide pyrethrin is responsible for the insecticidal activity of Dalmatian pyrethrum (Tanacetum cinerariifolium /Trevir./ Sch. Bip.). In order to obtain deeper knowledge of its insecticidal potential, the extraction of mentioned components from plant samples was carried out for the first time, by matrix solid-phase dispersion. The influence of different factors such as the type of sorbent, sorbent-sample ratio, the elution solvent and its volume, addition of co-sorbent and drying agent, affecting extraction yield was evaluated. The pyrethrin components were extracted under optimized conditions: florisil (0.5 g) as the sorbent, mixed with 0.25 g of pyrethrum flower heads, 5 mL of acetone-ethyl acetate (1:1, v/v) as the elution solvent and 0.4 g of Na2SO4 as the drying agent. All six components in the extracts were qualitatively and quantitatively determined by HPLC-DAD. Analytical method provides high degree of linearity with r2≻0.9974, except for pyrethrin II (0.9961). Also, the method showed good precision (intra- and inter-day) with a relative standard deviation below 14 %, and recoveries mainly above 80 %. In order to demonstrate the applicability of the developed method, three Dalmatian pyrethrum natural populations from Croatia were analyzed.