Portulaca oleracea, commonly known as purslane, is a popular plant of considerable value for its nutritive composition as well as traditional medicinal uses. P. oleracea is reported to possess neuroprotective, antimicrobial, antidiabetic, antioxidant, anti-inflammatory, antiulcerogenic, and anticancer activities. Three taxa of P. oleracea L. (P. oleracea, P. rausii and P. granulatostellulata) are grown as mixed populations in several locations in Egypt. The close morphological similarities among these taxa warrants development of methods for their correct identification or classification. We aimed in this study to assess metabolome differences among three P. oleracea taxa via ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) in the context of their genetic diversity and/or geographical origin. A total of 85 metabolites were identified including 6 amino acids, 22 phenolic compounds, 16 alkaloids, and 11 fatty acids characterized based on their MSn and UV spectra. Methoxylated flavone glycosides, O-flavonoids, C-flavonoids and four previously undescribed cyclodopa alkaloids are reported in P. oleracea for the first time. Multivariate data analyses were used for samples classification and revealing that cyclodopa alkaloids (oleracein A, C, K and N) contributed the most for accessions classification. To the best of our knowledge, this study presents the first metabolite profile of Portulaca and its compositional differences that provide chemical based evidence for its nutritive and/or health benefits.
Keywords: Alkaloids; Chemometrics; Metabolites fingerprinting; Phenolics; Portulaca; Portulacaceae.
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