# Evaluation of _Sambucus nigra_ L. Biopotential as an Unused Natural Resource
## 1 Introduction  
The _Sambucus_ genus (the Adoxaceae family) includes several berry species, and among them is the most interesting and most important black elderberry (_Sambucus nigra_ L). Black elderberry is a widespread shrub, which grows at higher altitudes on the banks of the rivers, as well as in the brighter forests [1]. For centuries, the species of this genus were wild-growing plants, but nowadays, the extraordinary potential of their fruits and flowers usage have induced plantation cultivating of elderberry across Europe [2]. Montenegrian mountain Ljubisnja, especially canyon of Cehotina river, is a region rich in wild-grown elderberries. Their exploitation in this area is minor, although it is an unpolluted locality that offers good environmental conditions for the fine growth of elderberries. The elderberry fruits from this area have been used as a traditional remedy for the cold, flu or for the preparation of tea and jams [3], but they have never been applied in industry or subjected to scientific analysis.  
Some studies have reported that different types of small fresh berry fruits (raspberry, blackberry, blueberry, and aronia) are extremely rich in biologically active substances [4], which can reduce a risk of several diseases, including cardiovascular, and neurodegenerative ailments, diabetes, and various types of cancers [5; 6; 7]. Elderberries are receiving much attention due to the high content of bioactive components: anthocyanins, flavonoids, phenolic acids, stillenes, tannins, and carotenoids [1]. The content and chemical structure of these secondary metabolites are liable for their different biological abilities, such as antioxidant potential to inhibit enzymes involved in the pathogenesis of the different diseases, cytotoxicity, antimicrobial activity, etc. [8]. In order to facilitate their bioavailability and raise qualitative and quantitative composition of extracts, new techniques for isolation are developing extensively [9]. Modern extraction techniques, such as microwave-assisted (MAE) and ultrasound-assisted (UAE) extractions, are considered as an effective method for isolation of various bioactive compounds from plant cells, and they follow the basic principles: maximized extraction yield, customization for industry requirements, avoidance of impurities and toxic compounds, prevented deterioration and loss of functionality during extraction, which all increases the quality of final products [10].  
As the previous data showed that some European elderberries exert anti-inflammatory [11], antioxidant [12], antiviral [13], antimicrobial [14], and anticonvulsant [15] activity, the aim of this study was to evaluate biological potential and its correlation with phytochemical composition of fresh elderberry fruits extracts, which were obtained using modern ((MAE), (UAE)) and traditional (macceration (MAC)) extraction techniques. Detailed quantitative and qualitative analysis (LC-MS/MS) of phenolic composition was performed. Neuroprotective, antioxidant, anti-tyrosinase, and anti-diabetic potential of the prepared extracts have been analyzed. Results of the polyphenol content and the analysis of biological activities are closely related to the applied extraction techniques. Therefore, an estimation of the capacities and abilities of the extraction techniques has been made with the goal to obtain highly valuable extracts, which could be used in food, pharmaceutical and cosmetic industry.