Morphological Traits and Phenolic Compounds in Tunisian Wild Populations and Cultivated Varieties of Portulaca oleracea L.

Abstract

<jats:p>This study aims to evaluate the bio-morphological and biochemical variability of three Tunisian wild populations and one growing cultivar of purslane (Portulaca oleracea L.). The studied varieties should be easily distinguished by the color and the habitus of the plant as mentioned in literature, but the various analyses have shown a strong morphological heterogeneity within and among the wild and cultivated accessions as presented by the variance analysis test (ANOVA) and the PCA (Principal component analysis). We found high intrapopulation variability through the wild populations that make it hard to differentiate them only on the base of morphology. We analyzed the biochemical profile of those populations based on the analysis of freeze-dried samples of leaves and stems. We identified and quantified twelve different phenolic compounds by the HPLC-diode array detector (DAD) technique. Six phenolic acids and flavonoids were identified in the leaves and stems of the wild and cultivated populations. Sinapic acid and myricetin are the majors identified compounds through our samples. The results were significantly different in relation to the plant organs and to the geographic origin for most of the compounds. The obtained results highlighted the importance of Portulaca as a medicinal plant by showing its richness in phenols and flavonoids that have multi-medicinal effects besides their antioxidant power.</jats:p>

Evaluation of Pigments, Phenolic and Volatile Compounds, and Antioxidant Activity of a Spontaneous Population of Portulaca oleracea L. Grown in Tunisia

“…Independently from the solvent used for extraction, flavonoid contents were significantly higher in leaves than stems. These results are in accordance with those of Xu et al [6], who reported kaempferol and apigenin compounds as the most abundant flavonoids, and also with findings of Sdouga et al [46], who reported myricetin and rutin as the major compounds in leaves and stems, respectively. By contrast, Zhu et al [7] found that total flavonoid contents were higher in stems than leaves.…”

“…Comparing the different extracts in both leaves and stems, a significantly higher content (p < 0.05) of total phenols was obtained in leaves in both ethanolic (13.92 mg g −1 ) and aqueous extracts (2.45 mg g −1 ). Furthermore, total phenol contents found in this study were higher than those found by Santiago-Saenz et al [75] and Sdouga et al [46]. Previously, Sicari et al [15] measured total phenol contents in dried leaves of P. oleracea in both aqueous methanolic extracts and ethanolic ones, and they found the highest contents in the latter.…”

“…These findings did not corroborate with the results of Alam et al [31], and this can be attributed to both the different accessions analyzed and the environmental conditions. Finally, we obtained lower values of total carotenoids as compared to those reported by Sdouga et al [46] performed on spontaneous populations of purslane collected in other Tunisian areas. This confirmed the relevant role of environmental conditions on the biosynthesis of phytochemicals.…”

“…However, our results revealed that ethanolic extraction was also efficient at obtaining a high amount of total phenols. This may explain why we obtained significantly higher amounts of total phenols than values reported by Sdouga et al [46], who determined the level of these bioactive compounds in Tunisian purslane by adopting acetone as the solvent for extraction.…”

“…Celak, which is the cultivated form. Despite extensive studies on the chemical and bioactive properties of this species throughout the world [31][32][33][41][42][43][44][45], less information is currently available on the phytochemical characterization of this species grown in Tunisia [46], a possible area of its origin as other North African countries. Therefore, in the present study, we aimed to characterize the phytochemical compounds present in leaves and stems of a spontaneous population of P. oleracea grown in Tunisia, as well as to evaluate the antioxidant capacity of their ethanolic and aqueous extracts.…”