## 3 Results and Discussion  
The hydrodistillation of samples of dried _Pimpinella lutea_ aerial parts collected in separate bioclimatic zones (North Bizerta, South Bizerta, and Tabarka) afforded three yellowish essential oils, with yields of 0.49%, 0.46%, and 0.41%, respectively). Table 2 displays the findings of the initial chemical analysis of essential oils extracted from different Tunisian locations. The volatile oil's chemical composition was determined using GC-FID and GC-MS techniques. To increase the reliability of identification, the mass spectra and the calculated LRI were compared with those of the same substances computerized in the data bank. According to the resulting analysis, a total of 73 organic volatiles were identified: 39 from NBEO (North Bizerta location), 44 from SBEO (South Bizerta location), and 51 fromTEO (Tabarka location), representing 76.2%, 94.6%, and 97.6% of the whole essential oil constituents, respectively. Despite some variations in phenotype structures depending on the environmental sources, common patterns in qualitative composition were established. _Pimpinella lutea_ essential oils consisted of monoterpenes and sesquiterpene hydrocarbons, oxygenated sesquiterpenes and phenyl derivatives, as shown in Figure 2.  
A specific feature of _Pimpinella lutea_ essential oil is the predominance of sesquiterpenes constituting the main groups in NBEO (72.2%), SBEO (78.1%), and TEO (60.2%). Even though this fraction dominated in all volatile oils, some qualitative and quantitative chemo-geographical variability was clear in all samples. In particular, the acorane sesquiterpenoid acora-3,7(14)-dien Figure 3 was quantified at a reasonably high concentration (29.1%) in TEO but in a significantly lower amount in NBEO (3.4%) and SBEO (4.7%), respectively. Moreover, \(\beta\)-pinene ranked second in abundance for _Pimpinella lutea_ collected in the sandy soil of Tabarka. At the same time, it occurred at a shallow mean content in SBEO (1.1%) and was completely absent in the sample harvested in the calcareous many soil (NBEO). It is worth mentioning that several studies have demonstrated the anti-cancer properties and the high activity of \(\beta\)-pinene against both Gram-positive and Gram-negative bacteria and _Candida albicans_ yeast [32]. \(\alpha\)-trans-Bergamotene identified as the primary sesquiterpene metabolite in NBEO (18.1%) was less observed in SBEO (6.4%) and as a trace element in Tabarka's sample (1.5%) (Table 2). In addition, It is interestingly noticeable that NBEO and SBEO were distinguished by almost equal amounts of muurola-4,10(14)-dien-1\(\beta\)-ol ranging from 8.9% to 10.1% in both samples, respectively. In contrast, this compound was not detected in TEO. Fokienol, the second interesting odorant in SBEO (9.1%) against a deficient level in NBEO, was utterly absent in TEO. As evidenced by previously published studies, this variation in terpene metabolites might be attributed to different climatic and eadpatic conditions. On reviewing the literature, several studies were performed on the chemical composition of essential oils extracted from _Pimpinella antiserum_ L. seeds, widely used as a culinary ingredient. The results revealed that in contrast to _Pimpinella lutea_ (Desf. ), Tunisian aniseeds contained noticeable amounts of phenylpropanoids (more than 95%) and were primarily composed of trans anethole (94.3%). However, _P. antiserum_ essential oil was very poor on sesquiterpenes hydrocarbons [33].