English abstract
Pteropyrum scoparium Carpet-Weed (Aizoaceae) was investigated for non-nutritional benefits because the green parts of the plant are eaten in Oman as vegetable meal. In this investigation the antioxidant activities, the total phenolic content and antimicrobial toAc extract of P. scoparium were determined. The EtoAc extract showed activity against Staphylococcus aureus and Klebsiella pneumoniae at 1000 ug/ml and partially inhibited the growth of Pseudomonas aeruginosa. The total phenolics content of aerial parts of P. scoparium clearly showed that the plant is a rich source of phenolic compounds. The phenolic content of the EtoAc extract was 4.4608 + 0.0548 mg/g of plant extract in gallic acid equivalent; and the EXOA displayed better DPPH radical scavenging activity at percentage inhibition (%IP) value of 83.47 $ 0.06 %. Further purification of the EtoAc extract led to the isolation of known procyanidin monomer, epicatechin-3-0-gallate (51) and detection of other monomers in ESIMS. Epicatechin 3-D-gallate was identified by NMR, ESIM$ and IR spectroscopy, and two other oligomers were detected in the ESIMS spectra of partially purified fractions. In terms of %IP, epicatechin-3-0- gallate showed strong free radical inhibition (85.72 = 0.02) % in the DPPH assay and its total phenolics character was found to be 6.238 + 0.208 mg/g in gallic acid equivalent. The result of ABTS assay of epicatechin-3-0-gallate showed a rapid decrease in absorption value in the first 2 min which was close to O by the 6th min. Based on these results, the consumption of P. scoparium could possibly offer some dietary benefits as it contains antioxidant constituents such epicatechin-3-0-gallate, which can protect against free radicals and some form of cancer.
