Abstract
This work focuses on the variability of Retama raetam (Forssk.) Webb bioactive compounds as a function of the plant cycle. The main results showed that it exhibited the highest percentage of polyunsaturated fatty acids, along with superior levels of vitamin C and total phenolic compounds (66.49%, 645.6 mg·100 g−1 FW and 23.9 mg GAE·g−1, respectively) at the vegetative stage. Instead, at the flowering and mature fruiting stages, R. raetam (Forssk.) Webb exhibited notable contents of proline (25.4 μmol·g−1 DW) and carotenoids (27.2 μg·g−1 FW), respectively. The gathered data concerning the antioxidant activity highlighted the effectiveness of the vegetative stage in comparison to the other periods. Actually, IC50 and EC50 values of the hydromethanolic extract obtained from the plant shoots at the vegetative stage were of 23, 380, 410, 1160 and 960 μg·mL−1 (DPPH• and ABTS•+ radicals scavenging activity, reducing power, chelating power and β-carotene bleaching activity, respectively). Furthermore, the four studied stages showed appreciable antibacterial capacities against human pathogens with a higher efficiency of the vegetative stage extract. Finally, the LC-DAD-ESI/MSn analysis revealed the predominance of isoflavonoids as main class of phenolic compounds and demonstrates that individual phenolic biosynthesis was clearly different as a function of plant growth. These findings highlight that reaching the optimum efficiency of R. raetam (Forssk.) Webb is closely linked to the physiological stage.
Highlights
Antioxidants, i.e., molecules that decelerate or prevent oxidation by impairing the oxidation chain reactions, can be classified in hydrophilic and hydrophobic compounds, according to their polarity [1]
It is possible that the carotenoids richness in R. raetam (Forssk.) Webb mature fruiting stage is partly associated with the involvement of these secondary metabolites in seed dispersion and plant perpetuation [19]
Retama raetam (Forssk.) Webb samples were collected from the Sebkha of Soliman (30 km from capital of Tunis; 36◦ 420 5000 N and 10◦ 240 3100 E; superior semi-arid bioclimatic stage; mean annual rainfall: 500–600 mm) at different periods: 1234
Summary
Antioxidants, i.e., molecules that decelerate or prevent oxidation by impairing the oxidation chain reactions, can be classified in hydrophilic and hydrophobic compounds, according to their polarity [1]. Water-soluble antioxidants react with oxidants in the cell cytoplasm and the blood plasma, while lipid-soluble antioxidants protect cell membranes from lipid peroxidation [2]. These compounds may be biosynthesized or obtained from the diet. Plants are good sources of bioactive compounds, including lipophilic antioxidants, such as tocopherols, carotenoids, and unsaturated fatty acids, as well as hydrophilic antioxidants, including ascorbic acid and phenolic compounds. These bioactive compounds exhibit beneficial effects such as antioxidant activity, inhibition or induction of enzymes, inhibition of receptor activities, and induction and inhibition of gene expression [4,5,6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
