## 2 Results and Discussion
### LC/DAD/ESI-MS\({}^{n}\) Bioactive Compounds Analysis  
The specific bioactive composition of the monoflorl bee pollen was successfully identified and quantified after extraction using the LC/DAD/ESI-MS\({}^{n}\) chromatographic method, based on its molecular structure. The proposed compounds, with their retention time, maximum absorption wavelengths, and mass spectral data in negative ion mode, are summarized in Table 3. The interpretation of fragmentation pathways in the MS\({}^{n}\) spectra of individual bioactive compounds was evaluated by comparing it with the results reported in the literature, and by assessing it alongside spectral information from the maximum UV. The chromatographic profile allowed the identification of two major groups of compounds in all extracts, as follows: (i) flavonoids, mainly flavonoids, and (ii) phenylamides. These were present in a total of seventy-two compounds (Table 3). A variety of different flavonol glycosides were identified in all extracts, with different degrees of substitution, mainly involving kaempfer, quercetin, isorhammetin, herbacetin, myricetin, and laricitrin. The sugar moieties in the flavonoids were assigned to pentosides, hexosides, and deoxyhexosides. Additionally, acetyl- and malonyl glycosides that were linked to the flavonoids were also found. As denoted in previous studies [6; 10; 12; 23], these compounds are frequently identified in bee pollen samples with different botanical origins, and are responsible for the biological activities of bee pollen. The total flavonoid compounds of samples BP1 and BP3 were very diverse, but the individual contribution of each compound was not higher than 15%. The same does not apply to sample BP7, wherein three isorhamtein glycosides accounted for more than 62% of the flavonoid compounds. This flavonoid aglycone was specific to _Castanea_ sp. pollen. For BP2, dominated by the _Ligustrum_/_Olea_ sp. pollen species, quercetin-O-diglucoside (\(m/z\) 625) was detected at a high concentration, with a value of 4.88 \(\pm\) 0.09 mg/g (65% of the total flavonoids). For BP4 and BP6, although collected in different geographical regions, the phenolic profile was similar, which indicates that they were of the same floral origin, _Rubus_ sp. Even though some small variations in the individual quantities of each compound were observed between the samples, it is notable that the major compounds were the same. Additionally, this botanical origin seems very rich in methyl herbacetin glycosides. Conversely, in _Echium_ sp. pollen, BPS5, kaempfer glycosides are the major flavonoids, with kaempfer-3-\(O\)-rutinoside (\(m/z\) 593) found in the highest concentration, at 2.61 \(\pm\) 0.03 mg/g. It is clear that bee pollen samples contain several phenolic compounds, but it seems that there is a specific flavonoid abundance which corresponds with the botanical origin. LC-MS analysis also revealed the presence of another group of compounds that are common in bee pollen--phenylamides. [PERSON] et al. recently confirmed the richness of monofloral bee pollen from China by identifying 31 phenylamides [31]. These compounds are found in high amounts in the pollen structure of higher plants, both in mono- and di-costs [32]. Phenylamides are derivatives of polyamines and are considered plant-specific secondary metabolites with a variety of functional roles under stress conditions [33]. They play an important role, not only against biotic stress, but also against abiotic stress, as it is the defensive mechanism of phenylamides, which works against plant pathogens; this has been well summarized in previous studies [33; 34]. These findings help explain the accumulation of phenylamides in high amounts, in various tissues of plants (including pollen grains). These low-molecular compounds are products of covalent bonding between carboxylic groups of hydroxycinnamic acids, and amine groups of aliphatic di- and polyamines or aromatic monoamines [32].