## 3 Results and Discussion
### Analysis of Metabolites
The main components of _Alpinia galanga_ are 1,8-cineole, \(\alpha\)-fenchyl acetate, \(\beta\)-myrcene, \(\beta\)-ocimene, camphor, and limonene [28]. The main components of _Alpinia zerumbet_ are 1,8-cineole, camphor, p-cymene, and terpinen-4-ol [29]. The main components of _Alpinia oxyphylla_ are p-cymine, estragol, copaene, and so on [30]. However, there is currently limited research on the composition of the fruits of _Alpinia Katsumadai, Amomum paratsoako, Alpinia japonica_, and _Zingiber striolatum_. There were certain differences in the relative content of some compounds from previous reports compared to the results of this study. The reason for this situation was that there were certain differences in the components obtained using different extraction methods. Another important reason was the heterogeneity of the biological samples. It can also be seen that there are certain differences in the metabolites and relative contents detected between the same species. This is because the differences in metabolites are not only related to species, but also influenced by factors such as cultivation conditions, harvesting periods, processing methods, and so on [31]. Moreover, the four terpen jointly identified from thirteen samples were 1,8-cineole, linalool, \(\alpha\)-pinene, and camphene, which have unique functions and biological activities (Table S1). 1,8-cineole is a saturated monoterpene that has the ability to treat respiratory diseases, cardiovascular illness, and digestive sickness [32]. As a kind of acyclic monoterpene alcohol, linalool naturally presents in various aromatic plants and has some bioactive properties including anticancer, antimicrobial, neuroprotective, anxiolytic, antidepressant, anti-stress, hepatotoxicity, renal protective, and lung protective activities [33]. \(\alpha\)-pinene is a member of the monoterpene group which has been used in the treatment of respiratory tract infections and has antibacterial and insecticidal activities. In addition, it also plays an important role in the flavor industry [34]. Camphene belongs to the group of monoterpene hydrocarbons, and it has been proven that it has antibacterial, anticancer, antioxidant, antiparasitic, antidiabetic, anti-inflammatory, and hypolipidemic activities [35]. Even though the components of the different species have similar metabolic components, there are still certain differences in their relative content. Hierarchical clustering analysis (HCA) could more intuitively reflect the difference in the content of metabolites between samples, and the heatmap could further visualize this difference. HCA was performed on metabolites from different samples, and the heatmap is shown in Figure 2. Among them, 9 metabolites, 26 metabolites, 18 metabolites, 36 metabolites, 20 metabolites, 23 metabolites, 18 metabolites, 25 metabolites, 8 metabolites, 17 metabolites, 10 metabolites, 25 metabolites, and 10 metabolites were upregulated in _Amomum koenigii_ (A), _Amomum kravanh_ (B), _Amomum longiligulare_ (C), _Amomum tsaoko_ (D), _Amomum villosum_ (E), _Amomum maximum_ (F), _Amomum paratsaoko_ (G), _Alpinia galanga_ (H), _Alpinia katsumadai_ (I), _Alpinia zerumbet_ (J), _Alpinia japonica_ (K), _Alpinia oxyphylla_ (L), and _Zingiber striolatum_ (M), respectively. Among them, _Amomum koenigii_, _Amomum villosum_, _Amomom longiligulare_, and _Alpinia zerumbet_ are clustered together due to similar metabolites. Trichyolo [2.2.1.0 (2,6)] heptane, 1,7,7-trimethyl-, (-)-camphor, borneol, and camphene have relatively high levels of metabolites compared to other spices, which is an important basis for distinguishing other spices. Some spices have detected unique metabolites, such as trans-p-mentha-1(7),8-dien-2-ol (_Amomum kravanh_); 2-n-butyl furan (_Amomum tsaoko_); methylamine, N,N-dimethyl-, \(\beta\)-bourbonene, and (S,1Z,6Z)-8-isopropyl-1-methyl-5-methylenedecyclodeca-1,6-diene (_Amomum maximum_); 8-heptadecene (_Alpinia galanga_); acetophenone (_Alpinia katsumadai_); benzene and n-butyl- (_Alpinia oxyphylla_).