Phytochemical profiling and antioxidant activity of Linum trigynum

Abstract In this study, the total phenolic and flavonoid contents (TPC and TFC), secondary metabolite composition (LC-HRMS/MS analyses) and antioxidant potential (DPPH, ABTS, GOR, CUPRAC, and phenanthroline assays) of Linum trigynum L. (LT) extracts were determined. Our results showed for the first time that the extracts (PE, CHCl3, AcOEt, and n-BuOH) of LT exert antioxidant activity. The AcOEt and n-BuOH extracts were the most antioxidant compared to the standards, and had a higher amount of TPC (323.51 ± 0.62; 229.98 ± 6.80 µg GAE/mL) and TFC (183.75 ± 1.17 and 157.50 ± 1.77 µg QE/mL), resectively. The high antioxidant properties of these extracts may be due to their major compounds (phenolic compounds) detected by LC-HRMS/MS analyses including flavonoids (40 compounds) and phenolic acids and derivatives (18 and 19 compounds, respectively). AcOEt and n-BuOH extracts of LT can be used as an excellent source of antioxidant phytochemicals to prevent or treat various diseases. Graphical Abstract


Introduction
plants have been used as medicine and therapy for over 5000 years.according to current data, the plant kingdom contains nearly 250,000 plant species, of which only about 10% of medicinal plants have been discovered and studied so far for treatment of many diseases (Fridlender et al. 2015;Siddiqui et al. 2022).the algerian flora is characterized by a high proportion of endemic plants (Greuter 1991), despite the number of bioactive compounds that exist; there is still a need to discover original active therapeutic and protective compounds.Several extraction procedures were utilized to extract bioactive compounds from plants, ranging from more traditional techniques such as maceration to new technologies, solid-phase microextraction (SpmE), stir-bar sorptive extraction (SBSE), liquid-phase microextraction (LpmE), ultrasonic-assisted extraction (uaE), microwave-assisted extraction (maE), pressurized liquid extraction (pLE) and supercritical fluid extraction (SFE), etc., are required to obtain these compounds (alahmad et al. 2023).phenolic compounds constitute the most important group of natural compounds that present antioxidant, cytotoxic, anti-inflammatory, antidiabetic, and hypolipidemic effects.these effects are essential to prevent or treat neurodegenerative disorders, cancer, and cardiovascular diseases (miceli et al. 2016; alam et al. 2018; alesci et al. 2022; mouna et al. 2023).over time, the analytical methodology for the analysis of phenolic compounds has evolved from the determination of total content by spectrophotometric methods to identification and quantification through the use of high resolution analytical techniques, such as nuclear magnetic resonance (nmR) and mass spectrometry (mS), which is usually coupled with chromatographic techniques: Liquid Chromatography (LC), Gas Chromatography (GC) and ion Chromatography (iC) and Capillary Electrophoresis (CE) to increased dynamic range and resolution (Zhu et al. 2023).it is with this aim in mind that our work consists, on the one hand, in identifying the secondary metabolites of the Linum trigynum L. (Lt) plant and, on the other hand, in studying their antioxidant effect.

LC-HRMS/MS analyses
the secondary metabolite composition of n-BuoH and acoEt extracts was analyzed by LC HRmS/mS. the metabolites were identified using the GnpS (Global natural product Social molecular networking) platform.

Experimental
the experimental section is available online in the supplementary material.

Conclusion
our results demonstrated, for the first time, that extracts (pE, CHCl 3 , acoEt and n-BuoH) of L. trigynum L. exerted antioxidant activity (dppH, aBtS, GoR, CupRaC, and phenanthroline assays).the polar extracts (n-BuoH and acoEt) showed better antioxidant activity compared to the apolar extracts (pE and CHCl 3 ), this activity could be due to their richness in polyphenols (flavonoids and phenolic acid and derivatives) which were identified by LC-HRmS/mS and/or to other compounds present in the extract which may act as reducing and free radical scavenging agents.the n-BuoH and acoEt extracts can be used as a valuable source of antioxidant drug for the prevention and treatment of many diseases.

, 73, 82, 83, and 84) and
3 fatty acids (2, 88, and 89) were also found.Comparing our obtained results with our previous study(Ryma et al. 2022), a total of 75 compounds were detected in the acoEt extract of Lt. the same compounds (