# Influence of Altitude on Phytochemical Composition of Hemp Inflorescence: A Metabolomic Approach
## 2 Results and Discussion
### Trepenoids Profile Estimated by HS-SPME- GC-MS Analytical Procedure  
Monoterpenes, diterpenes, triterpenes, and sesquiterpenes are important components of the _C. sativa_ resin responsible for its unique aromatic properties [20; 21]. Considering the terpenids fraction characterized by high-volatile features, the headspace solid-phase microextraction-gas chromatographic mass-spectrometric (HS-SPME-GC-MS) analytical approach presents the best methodology for their comprehensive profiling, as was confirmed by our recently published studies [12; 24; 25]. SPME is a simple and fast modern tool used to characterize the volatile fraction of secondary metabolites of different parts of plants [26; 27] and animals [28].  
Complete data concerning the terpen fingerprint in the two groups of Kompolti infloresances are summarized and reported in Table 1 It was possible to define 20 compounds that belong to the mono/di/tri terpenes and 21 sesquiterpenes. Our results are qualitatively comparable with those reported by others [19; 20; 22; 29]. The most remarkable aspect is that four M clones expressed significantly higher amounts of both terpenoids subgroups, with high variation in the individual quantitative profile. This is the reason why the results are elaborated by statistical approach that consisted of the comparation of relative amounts of each compound between mountain and corresponding plain clone. Generally, the predominant monoterene was \(\beta\)-myrrene, followed by both \(\alpha\)-/\(\beta\)-pinene and limonene, although without uniformity between four plants (Table 1). For example, the plant M2 was particularly rich in \(\beta\)-myrrene, followed by \(\beta\)-pinene and limonene, but not \(\alpha\)-pinene. On the other hand, the plant 1 (both M and P samples) expressed its specificity in the accumulation of \(\beta\)-ocimene, while others were very poor in its presence. Also, plant 1 contained the oxygenated terpene 4,8-epoxy-p-menth-1-ene that was completely absent from other infloresances.  
Geographic origin, accompanied by environmental conditions, turned out to be an important variable that determined the sesquiterpenes' quantitative characteristics: mountain plants exhibited higher total amounts than plains counterparts, with trans-caryophyllene and \(\alpha\)-humulene as the main contributors (Table 1). Those two compounds are typical constituents of _C. sativa_ essential oil [30], and also here showed a quite stable relevance. Selina-3,7(11)-diene was detected in a moderate amount in all mountain samples, but its presence was not detected in two plains clones. \(\alpha\)-ylangene, \(\alpha\)-bergamotene and \(\beta\)-farnesene expressed highly inconsistent trends. For example, P1 samples were particularly abundant in \(\beta\)-farnesene, while in plant 3 (both P and M samples) it was absent. All samples contained longicyclene, the sesquiterpene rarely identified in _C. sativa_ infloresences, with the exception of one drug-type chemovar [31].  
In all cases, the qualitative and quantitative differences observed in the chemical profile of terpene fractions were conditioned by many factors such as, hemp variety, cultivation and environmental conditions, harvest time and post-harvest conditions, storage and drying of raw plant, and extraction procedure applied. Despite the fact that within each group, plants were grown under identical conditions and treated in the same way, it remains an open question why each of them had its specific terpen fingerprint.