## 1 Introduction  
_Aquilaria sinensis_ (Lour.) Gilg, belonging to the genus _Aquilaria_ (Thymelaeaceae), exhibits a wide distribution across various Asian countries such as China, Vietnam, and Laos, among others [1]. It holds a prominent position as the sole primary source of domestic medicinal agarwood in the Chinese Pharmacopoeia, possessing significant medicinal and economic value. The aromatic resin known as agarwood is secreted in the wounds of the stems, and it is activated by plant defense responses when subjected to injury, insect pests, or microbe-attacked [2, 3].The use of agarwood in traditional Chinese medicine encompasses pain relief, digestion promotion, antiemetic effects, and sedation [4]. Contemporary pharmacological research has revealed that agarwood essential oil possesses antioxidant, neuroprotective, antibacterial, and sedative properties [5]. Moreover, agarwood finds extensive application in the perfumery industry as well as in incense and sculpting collections [6]. Due to its extensive market demand and protracted formation process, wild agarwood resources have been exploited to the point of extinction, leading to a severe depletion of natural agarwood sources. To ensure the protection and sustainable development of wild agarwood resources, all _Aquilaria_ spp. have been listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES, [[http://checklist.cites.org](http://checklist.cites.org)]([http://checklist.cites.org](http://checklist.cites.org)), accessed on 1 January 2024). Whether other tissue parts and tissue culture materials could be used as potential substitutes for agarwood in the future has been the novel focus of research. Currently, the stem of _A. sinensis_ serves as the primary source of agarwood. It is worth exploring whether similar components of agarwood exist in other tissue parts and callus materials. The study revealed significant differences in the structure of agarwood isolates compared to various non-resinous tissues. Sesquiterpenes and 2-(2-phenylethyll) chromome derivatives are identified as the principal and distinctive chemical constituents of agarwood [7, 8, 9]. The sesquiterpenes in agarwood can be classified into various groupsbased on their skeletal structures, including agarofurans, agarospiranes, cadinanes, guaianes, eudesmanes, zizaanes, eremophilanes, prezizaanes, humulanes, and others [10]. In addition, agarwood also contains various secondary metabolites, including aromatic hydrocarbons, triterpenoids, steroids, and alkaloids [11]. To date, over 200 compounds have been isolated from various parts of _A. sinensis_, including leaves, twigs, barks, and roots. These compounds mainly consist of sesquiterpenoids, 2-(2-phenethyl)chromonone, triterpenoids, steroids, and aromatic agents [12]. Flavonoids were widely distributed in stems and leaves [13; 14; 15]. Benzophenones were primarily found in leaves, flowers, and pericarp, with a lesser distribution in stems [16; 17; 18]. Xanthones exhibited a specific distribution mainly in leaves and fruits [19], while lignans were predominantly present in stems [20; 21]. Additionally, phenolic compounds were mainly distributed in leaves, stems, and bark [22; 23]. Nitrogen-containing compounds and nucleosides commonly occur in leaves and petioles [21; 24]. A small amount of 2-2-phenethyl chromonone was detected in leaves, stems, and cell suspension cultures [23; 24; 25]. The distribution of triterpenoids was primarily observed in seeds, stems, and leaves [26; 27; 28], whereas triterpenoids and steroids were found in leaves, fruits, peels, petioles, and stems [7; 11; 13; 21; 22; 23; 24; 26; 29; 30]. However, these reports solely focused on the variances in compound types and chemical structures, failing to comprehensively compare the distribution characteristics and content disparities of metabolites across different parts, particularly terpenoid metabolites.