## 3 Discussion
Moreover, analysis of volatile compounds from fruits of _Seseli ilbuniotis_ (L.) [PERSON] also showed that higher contents of low-boiling compounds such as sabinene, \(\beta\)-phellandrene, \(\alpha\)-pinene, \(\beta\)-pinene, \(\beta\)-myrcene, \(\gamma\)-terpinene and \(\alpha\)-phellandrene may be extracted by using HS-SPME than by hydrodistillation, while higher amounts of high-boiling compounds (higher molecular mass and lower volatility) were observed using hydrodistillation at high temperature [61]. Qualitative and quantitative differences of volatile compounds of _Melissa officinalis_ L. were observed after applying hydrodistillation and HS-SPME, which may be attributed to the formation of artifacts [6]. Furthermore, variations in the percentages and nature of compounds adsorbed on a SPME fiber compared to those found in hydrodistilled EOs were reported for _Petroselinum crispum_ Mill. [62], while the comparison of the same techniques on _Bupleurum plantagineum_ Desf. showed differences mainly in minor components [63]. Therefore, despite some differences, the results obtained by HS-SPME considering the major VOCs may be comparable to the results obtained by hydrodistillation [61; 62; 63]. In the studied samples, the most abundant VOCs, depending on the fiber used for solid-phase microextraction, were bicyclogermacrene (_S. romana_ K, _S. romana_ B and _S. romana_ P) and/or _trans_-caryophyllene (_S. romana_ P), benzyl alcohol or viridiflorol (_S. romana_ M), and germacrene D (_S. montana_ J and _S. montana_ M). These compounds were previously shown to possess certain biological activities that may be of interest to the pharmaceutical, food and/or cosmetics industry. For example, bicyclogermacene displayed cytotoxic activity against a range of cancer cell lines (IC\({}_{50}\) = 3.1-21 \(\upmu\)g/mL [64] and IC\({}_{50}\) = 1.5-4.4 \(\upmu\)g/mL). The same was observed for germacrene D (IC\({}_{50}\) = 2.7-8.0 \(\upmu\)g/mL) [65]. Additionally, germacrene D and _trans_-caryophyllene were recognized as the major EO constituents of selected species from the genera _Siparuna_ Aublet and _Piper_ L. that possess antiradical activity [66]. According to [PERSON] et al. [67], \(\beta\)-caryophyllene possesses antibacterial activity against _S. aureus_ (MIC = 3 \(\pm\) 1.0 \(\upmu\)M) as well as anti-fungal (MIC = 4-7 \(\upmu\)M), antioxidant (IC\({}_{50}\) = 1.25-3.23 \(\upmu\)M), and anti-proliferative activity against colorectal cancer cells (IC\({}_{50}\) = 19 \(\upmu\)M). Benzyl alcohol is frequently used as a bacteriostatic agent in liquid pharmaceutical products [68] as well as a preservative in cosmetic products [69]. On the other hand, antiradical (IC\({}_{50}\) = 57.55-74.7 \(\upmu\)g/mL), anti-mycobacterial (MIC = 190.0 \(\upmu\)g/mL) and anti-inflammatory activity (60% reduction of carrageenan-induced mice paw edema after 3-30 mg/kg oral administration) were reported for viridiflorol [70]. Moreover, viridiflorol was recently observed to induce intracellular Ca\({}^{2+}\) mobilization in human neutrophils and C20 microglial cells [71]. Related species of the genus _Sideritis_, namely _S. scardica_[22; 29; 72], _S. clandestina_ ([PERSON] and Chaub.) [PERSON] [21], _S. raeseri_[72; 73; 74], and _S. syriaca_ L. [22], whose aerial parts have been traditionally used for the treatment of inflammation, gastrointestinal disorders and cough associated with cold and whose usage has been approved by the European Medicines Agency (EMA) Committee on Herbal Medicinal Products (HMPC) [75], were observed to possess, as one of their major volatile constituents, the same VOCs that were found in _S. romana_ and _S. montana_ in the present study, thus, indicating a promising potential for future investigations of these species.