## 3 Results and Discussion  
### Essential Oils Composition  
The yields of essential oils (_v/w_) from HD and OS extracts of fresh rhizomes, flowers, and leaves of _Z. kerrii_ were (0.4%, 0.6%), (0.2%, 0.3%), and (0.2%, 0.3%), respectively. Rhizomes represented the highest percentage of essential oil yields using the OS technique. The chemical compositions of rhizomes, flowers, and leaves essential oils are shown in (Table 1). GC-MS analysis of _Z. kerrii_ rhizome essential oils showed 37, 19, and 36 different components using the SPME, HD, and OS techniques, respectively, of which 95.5%, 96.9%, and 90.8% were identified. The essential oils were mixtures of six chemical classes including monoterpeak hydrocarbons, oxygenated monoterpeas, sesquiterpene hydrocarbons, oxygenated monoterpeas, sesquiterpene components were \(\alpha\)-pinene (22.1% \(\pm\) 0.6%, 24.3% \(\pm\) 1.6%), \(\beta\)-pinene (17.2% \(\pm\) 0.7%, 33.1% \(\pm\) 2.5%), sabinene (12.3% \(\pm\) 1.7%, n/a), and (_E_)-\(\beta\)-ocime (8.1% \(\pm\) 0.3%, 7.8% \(\pm\) 0.5%) using the SPME and the HD techniques, respectively, whereas the major components of the OS technique included \(\beta\)-pinene (7.7% \(\pm\) 1.1%), (_E_)-\(\beta\)-ocime (4.1% \(\pm\) 0.8%), terpinen-4-ol (11.5% \(\pm\) 0.6%), germacrene B (4.2% \(\pm\) 0.6%), caryophyllene oxide (4.4% \(\pm\) 0.7%), and \(n\)-hexadecanoic acid (8.7% \(\pm\) 0.9%). The flower essential oils showed 16, two, and nine compounds, of which 99.1%, 97.2%, and 97.1% were identified. The main compound was _E_-caryophyllene (58.1% \(\pm\) 1.3%, 94.8% \(\pm\) 0.9%, 74.2% \(\pm\) 1.5%), which was identified via the SPME, the HD, and the OS techniques, respectively. The SPME technique showed \(\alpha\)-pinene (22.2% \(\pm\) 1.8%) and \(\beta\)-pinene (8.6% \(\pm\) 1.1%) as dominant compounds, but \(n\)-hexadecanoic acid (14.9%\(\pm\) 0.4%) was as a major compound identified by the OS technique. The isolated essential oils of leaves contained 20, 13, and 14 components, which represented 95.4%, 91.8%, and 93.1% of the total oil compositions, respectively. Most of the compounds in the leaves belonged to five chemical classes, which are listed in (Table 1). The major components of the essential oils in the leaves were \(\alpha\)-pinene (\(39.7\%\pm 0.7\%\)), \(\beta\)-pinene (\(6.3\%\pm 0.5\%\)), and (\(E\))-caryophyllene (\(21.2\%\pm 0.8\%\)) using the SPME technique, but the HD technique identified \(\beta\)-elemene (\(12.2\%\pm 1.3\%\)), (\(E\))-caryophyllene (\(24.2\%\pm 1.6\%\)), and valencene (\(21.2\%\pm 1.3\%\)) as the major components. (\(E\))-caryophyllene (\(6.0\%\pm 0.8\%\)), isodaucene (\(4.2\%\pm 0.9\%\)), and \(n\)-hexadecanoic acid (\(55.7\%\pm 1.3\%\)) were identified as the main compounds when the OS technique was used. The essential oil compositions of \(Z\). _kerrii_ (Table 1) were different according to the extract technique used. (\(E\))-Caryophyllene was the main compound seen in the flowers as identified by several techniques, with the exception of the SPME technique in the rhizomes. In addition, \(\alpha\)-pinene and \(\beta\)-pinene were found in several parts, except the flowers when the HD and the OS techniques were used. The results revealed that the HD and OS techniques lost some highly volatile compounds during the process of extraction [5; 8; 9]. The main compounds usually reported from \(Z\). _officiale_ include zingiberene, geranial, and other sesquiterpene hydrocarbons [34; 35], whereas literature data on the compositions of \(Z\). _zerumbet_ leaves reported (\(E\))-nerolidol, \(\alpha\)-pinene, and \(\beta\)-pinene as the main compounds [36]. In our results, \(\alpha\)-pinene, \(\beta\)-pinene, and (\(E\))-caryophyllene were found to be the major constituents of \(Z\). _kerrii_, which corroborated previous literature reports of \(Z\). _zerumbet_ leaves [36]. This work is the first investigation into the chemical compositions of essential oils from several parts of \(Z\). _kerrii_ using different techniques.