## 3 Results and Discussion
### Composition of Seed and Cone EOs
Understanding the components of essential oils highlights the strong biological properties of oxygenated derivatives of monoterpene hydrocarbons [15]. Sesquiterpenes were less abundantly represented in the hemlock EOs. Surprisingly, the seed oil was composed of 15% of sesquiterpenes, while the total content in the cone oil, also considering oxygenated derivatives of sesquiterpenes, was 0.4%. The compounds from this group that appeared in both oils were \(\alpha\)-humulene, humulene oxide II, \(\tau\)-muurolol, and \(\alpha\)-cadinol, while the seed EO was dominated by germacrene D (3%), (E)-\(\beta\)-caryophelene (2%), and \(\alpha\)-humulene (2%). Diterpene hydrocarbons and their oxygenated derivatives constituted a small percentage of the analyzed seed (2%) and cone (1%) EOs, although quite numerous. Pimaradiene and dehydrodietal were the majority in the above group. The differences in EOs composition are shown in Figure 1.  
In a similar research, needle EOs were obtained using hydrodistillation and analyzed via GC-FID and GC-MS of a wild variety of _T. canadensis_ in north Alabama and northwest Georgia, revealing the same major constituents of \(\alpha\)-pinene, camphene, and bornyl acetate [16]. However, the relative proportions were different, due to different plant parts and geographical location. Furthermore, in another study, the major constituents of EOs from needles of _T. canadensis_ were bornyl acetate (26.8%), \(\alpha\)-pinene (23.7%), and camphene (11.93%) [17]. Results of both studies indicate a common chemical profile for _T. canadensis_, but content levels could deviate. There is no analysis of the composition of oils from the seeds or cones of Canadian hemlock, so the composition will be compared with the composition of essential oils from the seeds and cones of other related conifer species. EOs from _Californian fir_ seeds and cones show notable differences compared to those from _T. canadensis_. _Abies concolor_ seed oil is dominated by monoterpene hydrocarbons, particularly limone (47.2%) and \(\alpha\)-pinene (40.2%), while cone oil contains higher levels of \(\alpha\)-pinene (58.3%) and sabinene (10.7%). Oxygenated monoterpenes occurred in lower content than monoterpene hydrocarbons in fir EOs [9], in contrast with _T. canadensis_ seed oil, which is rich in bornyl acetate (41.4%)--a volatile with a balsamic type odor and a camphorous type flavor. Notably, bornyl acetate occurred in significantly lower concentra  
Figure 1: The GC chromatograms of seed and cone essential oils of Canadian hemlock. tions in its cone oil (7.1%); thus, the scent of the seed oil is fresher compared to the heavy resinous scent of the cone EO. The high content of bornyl acetate (41.4%) in _T. canadensis_ seed EOs underscores its potential for cosmetic and therapeutic applications, particularly due to its fragrance, anti-inflammatory, and antimicrobial properties. However, practical challenges, such as formulation stability, compatibility with other ingredients, and effective delivery systems, need to be addressed. The chemical profiles of EOs are dependent upon the plant part used to obtain the essential oil, whether seeds, cones, or needles, and it may also be associated with the geographical origin [16]. The chemical profiles of _T. canadensis_ seed and cone EOs were compared with those of _Abies alba_ and _Pica orientalis_ using a bar chart (Supplementary Figure S1). Bornyl acetate, showed highly active whitening and antioxidant activities, which was confirmed in experiments based on bornyl acetate fractionated from _C. japonica_ essential oil. The authors of the experiments concluded that this ingredient may be a potential raw material in cosmetics. Globally, bornyl acetate is widely found in EOs from _Ledum pulstre_, Siberian fir needles, cinnamon twigs (_Cinnamomom osmophoeum_), _Pseudotsuga menziesii_, and _Chrysanthemum indicum_. This volatile is relatively stable under normal conditions but can hydrolyze into bornel and acetic acid under acidic or alkaline conditions.