## 4 Discussion
olympicum_ was examined by [PERSON] et al. [43; 52] and, according to their results, a broad spectrum of antimicrobial activity was observed against both Gram-positive and Gram-negative bacteria, including _S. aureus_ and _E.coli_. However, in our study, _H. olympicum_ did not inhibit Gram-negative bacteria. Nevertheless, new information is now available about its antibacterial activity against _E. faecalis_, a microorganism resistant to many antibiotics [53; 54]. There are limited studies that deal with the antibacterial activity of _H. perfoliatum_ and _H. rumiacum_ subp. _apollini_s [52; 55], while no previous studies were found for _H. vesiculosum_ and _H. cycladicum_. All these species are classified within sect. _Drosocarpium. H. perfoliatum_ was studied for its antimicrobial activity by [PERSON] et al. [55]. The methanolic extract did not exhibit antimicrobial activity; on the contrary, chloroform and chloroform-methanol extracts exerted significant antimicrobial activity against all the microorganisms tested. In our study, the _H. perfoliatum_ extract inhibited only Gram-positive bacteria, and in fact, the MIC and MBC values were equivalent for both microorganisms. Similar results were reported by [PERSON] et al. [52] regarding _H. rumiacum_ Boiss. The extract showed strong antimicrobial activity against life-threatening microorganisms, such as _K. pneumoniae_ and _S. enteritis_. In our study, _H. rumiacum_ subsp. _apollini_s inhibited only Gram-positive bacteria, and the inhibition of _E. faecalis_ by _H. perfoliatum_ and _H. rumiacum_ subsp. _apollini_s was reported for the first time. All the tested extracts were active against Gram-positive bacteria; however, considering the literature data, generally, _Hypericum_ spp. seem better for combating Gram-positive bacteria. _S. aureus_ and _E. faecalis_ are two microorganisms that resist some kinds of antibiotics, such as \(\beta\)-lactamase [56], tetracyclines, and macrolides [57]. Certainly, the biological activity of an extract is dependent on its phytochemical profile and the extraction technique used to isolate secondary metabolites. Consequently, considering the different geographical origins of the _Hypericum_ species used in this study, differences regarding their potency or inability to inhibit microorganisms are expected. Regarding the total phenolic and total flavonoid content, the most studied _Hypericum_ species are those of the _Drosocarpium_ section, followed by those of the _Hypericum_ section [17; 58; 59]. For example, [PERSON] et al. [59] studied, among others, some species from the _Drosocarpium_ and _Hypericum_ sections. Species from the _Hypericum_ section, specifically _H. perforatum_ and _H. tetraperum_, were reported to have the highest total tann content (8.67 \(\pm\) 0.02 g/100 g DW for _H. perforatum_) and TFC (1.13 \(\pm\) 0.02 g/100 g DW for _H. tetraperum_), respectively. Our results demonstrated a similar bioactivity when referring to the _Hypericum_ section, as _H. perforatum_ contained the highest content of phenolic compounds, while TFC was highest in the _H. tetraperum_ extract. According to [PERSON] al. [59], _H. olympicum_, a species of the _Olympus_ section, demonstrated a moderate quantity of total tannins (3.28 \(\pm\) 0.03 g/100 g DW), while the TFC was the lowest (0.20 \(\pm\) 0.03 g/100 g DW) compared to all the other studied species investigated. In our study, similar results were demonstrated regarding the TPC of _H. olympicum_. However, the TFC of the extract exceeded that of _H. perfoliatum_ and _H. vesiculosum_, belonging to the _Drosocarpium_ section. At the same time, for the TFC and the _Drosocarpium_ section, _H. cycladicum_ and _H. runeliacum_ subsp. _apollinis_ were the most abundant.