## 1 Introduction  
Nowadays, some representatives of bacterial or fungal strains cause very serious pneumonia or various invasive infections that are not easily treatable. The unwanted phenomena occur when pathogens are not sufficiently susceptible to the activity of commonly used therapeutic agents [1]. The increasing number of multidrug resistant bacteria is rather alarming, in fact; such an occurrence notable contributes to the increased spread of severe infections, which can even be a cause of death. Current clinically utilized antibacterial chemotherapeutic can become almost ineffective against these very serious or fatal threats. In this regard, the requirement of continuously searching for new antimicrobial promising molecules [1; 2] is logical and de facto mandatory. Scientific efforts to develop effective antibacterial agents with convenient structural, physicochemical, pharmacokinetic (PK), selectivity, and toxicological properties employ various research strategies, including those focused on plant-derived molecules, especially their secondary metabolites. Polyphenols represent a chemical class of naturally occurring compounds produced by various plants to protect themselves against potential environmental harm [3]. Biologically valuable **resveratrol (RSV: 1)**, chemically 3\(A\),_5-trihydroxystilbene (Figure 1), belongs to stilbenoids, pharmacologically a very attractive polyphenol family. These natural compounds (also termed natural products, NPs) share a typical structural arrangement of C6-C2-C6 [4; 5] employing two hydroxylated six-membered aromatic rings (two so-called C6 motifs) connected with a lipophilic acyclic ether-1,2-diyl moiety (C2 motif). The presence of a double bond [4; 5] allows the existence of cis- and trans-isomers (Figure 1) [6]; however, a biologically active trans-form is the dominant one with several favorable properties, including higher chemical stability, compared to the characteristics of a cis-isomer [7; 8]. The fundamental structural arrangement of stilbenoids differs from the arrangement found in the structures of other NPs, which also contain two aromatic ring systems [9], i.e., xanthones (C6-C1-C6) or flavonoids (C6-C3-C6). Stilbenoids belong to phytoalexins, a category of low-molecular-weight (\(MW\)) compounds produced locally within the structures of higher plants as their self-defense response to ultraviolet light and the harmful activity of various fungi, oomycetes, or bacteria [10; 11]. Those molecules can be chemically divided into several groups according to the presence of a phenolic, terpenoid, or indole scaffold. In addition, highly lipophilic \(S\)-atoms can also be incorporated in their structure [12]. Stilbenoids are commonly extracted from leaves infected with some fungal species, for example, _Plasmopara viticola,__Sphaeropsis sapinea_, or _Botrytis cinerea_[13; 14]. The plant secondary metabolite (**1**) was first isolated in 1939 from the roots of _Veratrum grandiforum_ [PERSON] by a Japanese researcher Dr. [PERSON] [15]. A few years later, from its isolation and characterization, the biologically active substance (**1**) was also found in the roots of _Polygonum cipsidatum_, a plant that has been widely used in traditional Chinese medicine [16]. The **RSV (1)** molecule is present mainly in _Vitis vinifera_; other common sources are _Vacinium vitis-idaea_, _V. myrtillus_, or _Arachis hypogea_[17]. The beneficial biological activity of the non-flavonoid phenolic compound (**1**) is directly related to the so-called French paradox. In fact, French people have a higher intake of various foods containing saturated fatty acids, but they hardly suffer from diseases that affect the cardiovascular (CV) system. Paradoxically, the death rate within the French population has been lower compared to that observed in other European nations. **RSV (1)**  
Figure 1: Chemical structure of **resveratrol (RSV; 1)**, a compound from a stilbenoid group.