Nada Bezic, has published more than 45 papers in international scientific journals in the field of virology, anatomy and physiology of xerophites and also their implementation in phytoterapy. Plant species that are the subject of research are from Mediterranean part of Croatia. Laboratory researches, apart from exploring plant structures, are focused on the isolation of plant compounds and their chemical characterization, as well as the determination of their biological activity. In recent years she is focusing on investigate is antiviral activity of essential oils. As a professor at the University of Split, she teach lectures and lead mentoring with students at the undergraduate, graduate and postgraduate level.
The genus Centaurea L. is very important genera of Asteraceae family, with many local endemic species. According to Flora Croatica database (http://hirc.botanic.hr/fcd) described 88 Centaurea species, of which 30 is the endemic. The investigated Centaurea tuberosa L. (synonim: Centaurea napulifera subsp. tuberosa (Vis.) Dostál) is also Croatian endemic species and this species belongs to the vegetation community of East Adriatic submediterranean and epimediterranean lawns: Chrysopogony-Koelerion splendentis.
This is the first study on the chemical composition of C. tuberosa species. investigated plants Tijarica (near Split) CroatiaAerial parts of plants were performed in a shady place at room temperature for 10 days. Dried aerial parts of plant material (100 g) were subjected to hydrodistillation for 3 h in Clavenger type apparatus. This essential oil have been analysed by GC (Varian 3900) and GC/MS (Varian Saturn 2000 system) using VF-5ms capillary column. The individual peaks were identified by comparison of their retention indices of n-alkanes to those of authentic samples and literature , as well as by comparing their mass spectra with the Wiley 9.0 library (Wiley, New York) and NIST/02 mass spectral database. The percentage composition of the samples was computed from the GC peak areas using the normalization method.
Total yield of oil was 0.55%, based on dry weight of sample. Thirty-seven compounds representing 82.9% of the total oil. The essential oil of C. tuberosa was characterized by a high concentration of caryophyllene oxide (27.8%), followed by β-caryophyllene (7.1%), docosane (6.8%), spathulenol (5.4%). Also, compounds β -caryophyllene, spathulenol and caryophyllene oxide were the common for the C. armena, C. appendicigera and C. helenioides . According to literature data, the composition of essential oils of Centaurea species are frequently characterized by components with sesquiterpenes skeleton such as caryophyllene, eudesmol, germacrene and spathulenol, hydracarbons and monoterpenes as pinene, terpinene, carvacrol [3-5].
The present study gives additional knowledge about phytochemical composition of the essential oil on the genus Centaurea.