## 3 Results and Discussion
### Phytochemical Characterization and Bioactivity
#### 3.3.1 Composition in Individual Phenolic Compounds
_nodiforum_ the avicularin (compound **27**) was the major flavonol. In \(S\). _ramossisima_, the flavonoids, quercetin 3-O-glucose (compound **53**), and the dimeric form of isorhamnetin glucoside (compound **82**) were the most abundant ones. This last compound was also previously reported by [PERSON] et al. [66] in _Mesembryanthemum_ genus. In the halophytes, the tentatively identified flavones were derivatives of apigenin, [M\(-\)H]\({}^{-}\) at \(m/z\) 269, chrysin, [M\(-\)H]\({}^{-}\) at \(m/z\) 253, acacetin, [M\(-\)H]\({}^{-}\) at \(m/z\) 283, and luteolin, [M\(-\)H]\({}^{-}\) at \(m/z\) 285, usually in their conjugated form with glucosyl (C\({}_{6}\)H\({}_{11}\)O\({}_{6}\)\(-\)), arabinosyl (C\({}_{5}\)H\({}_{9}\)O\({}_{5}\)-), and robinobiosyl (C\({}_{12}\)H\({}_{21}\)O\({}_{10}\)-) radicals. In _D. _crasifolium_, luteolin (compound **64**) was the major flavone. In _C. maritium_, the most abundant flavones were glycosidic forms of apigenin (compounds **25** and **60**), and in _M. crystallinum_, from the different flavones, the chrysin derivative (compound **50**) stood out by its abundance. This last result contradicts the higher relative abundance of apigenin, diosmin, and luteolin described by [PERSON] et al. [12] for _M. crystallization_ plants collected from the northwest coast of Spain (Galicia). Contrarily to most of the halophyte species, in _S. fruticosa_ and _S. rnmossissima_ no flavones were detected. The flavanols, derived from catechin isomer, with trans configuration, and epicatechin isomer, \([\mathrm{M-H}]^{-}\) at \(m/z\) 289, with cis configuration, were mostly found in their conjugated forms with galloyl, epigalloyl, and water residues. From the different studied halophytes, _S. fruticosa_ was characterized by the highest abundance of the epicatechin derivative (compound **55**), and _M. nodiforum_ was characterized by the highest abundance of epicatechin hydrate (compound **51**) and gallocatechin (compound **10**). The presence of epicatechin was previously reported in _S. fruticosa_ and _M. nodiforum_ plants [7], as well as in other halophyte species, such as _Spergulararia marina_ L. and _Glaux martiima_ L. [78]. Contrarywise, in _C. martiimum_, no flavanols were detected. The detected flavonones were derivatives of pinobanksin, \([\mathrm{M-H}]^{-}\) at \(m/z\) 271, pinocombrin, \([\mathrm{M-H}]^{-}\) at \(m/z\) 255, and eriodyciol, \([\mathrm{M-H}]^{-}\) at \(m/z\) 287, conjugated to ether, ester, or sugar groups. While I. _ctritmoides_ was particularly rich in the pinobanksin derivative (compound **31**), _M. nodiforum_ showed a higher abundance of eriodyciol (compound **49**) and its hexoside derivative (compound **48**), which was particularly abundant in _S. fruticosa_. The pinobanksin derivatives (compounds **16**, **31**, and **92**) were identified for the first time in the studied halophyte plants. However, the presence of pinobanksin in halophytes was previously described in the propolisis produced from _Zuccagnia punctata_, _Larrea divaricata_, and _Larrea cuneifolia_ halophytic shrubs, present in the vegetation of the Monte region in Argentina [88]. The presence of eriodictyol hexoside and pinocembrin was previously reported by [PERSON] et al. [89], in the halophyte _Helicthysum italicum_. In the flavananol class, only dihydroquercetin, also known as taxifolin (\(m/z\) 303), compound **36**, was detected. _S. fruticosa_ species was the only one with quantifiable amounts of this compound. This compound was recently associated with positive effects in nitric oxide production and endothelial dysfunction, contributing to a vasorelaxant effect and cardiovascular protection [90]. Compounds **28**, **57**, and **79**, not classified in the previous classes, were less abundant in the plants and present in _D. crassifolium, I. critmoides_, and _M. nodiforum_, respectively. Nevertheless, the positive impact of these compounds on human health has been extensively described [91; 92; 93].