This study presents the chemical profile investigation of a 70% ethanol extract obtained from Scabiosa stellata, a medicinal herbaceous traditionally used to treat heel cracks. A C NMR-based dereplication methodology was firstly applied on centrifugal partition chromatography-generated fractions in order to quickly identify the major compounds of the extract. The dereplication process was then completed by semi-preparative high-performance liquid chromatography in order to identify unknown or minor compounds. Two new bis-iridoids, namely 7-O-caffeoyl-sylvestroside I (1) and 7-O-(p-coumaroyl)-sylvestroside I (2), together with ten known compounds (3-12) were isolated. Their structures were elucidated by spectroscopic methods including NMR and HR-ESI-MS. The antibacterial, anti-tyrosinase and DPPH radical scavenging activities of the crude extract, fractions, and isolated compounds were evaluated. A significant antibacterial activity was observed for nine isolated compounds, particularly 1 and 2 which yielded MIC values of 31.2μg/mL against Enterococcus faecalis and 62.5μg/mL against Staphylococcus epidermidis. The cytotoxic activity of these new bis-iridoids was evaluated on a fibrosarcoma cell line (HT1080) and only compound 1 exhibited a moderate cytotoxic activity (IC 35.9μg/mL).

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Eight undescribed triterpenoid saponins, scabiostellatosides A-H, together with three known compounds were isolated from the whole plant of Scabiosa stellata L. Their structures were established by spectroscopic analyses (1D, 2D-NMR and HRESIMS) and chemical methods. Scabiostellatosides A-H were evaluated for their cytotoxicity against human fibrosarcoma cell line (HT1080). Scabiostellatoside F, a heptasaccharide derivative of oleanolic acid, exhibited moderate cytotoxicity against HT1080 cell line with IC value of 12.0 μM.

This study presents the bio-guided chemical investigation of a 80% methanol extract of Hippocrepis emerus flowers, a perennial non-climbing shrub. Liquid-liquid partitioning in solvents of increasing polarity combined to biological screening enabled to determine the EtOAc and n-BuOH soluble fractions as the most active parts of the extract. These fractions were chemically profiled by using a 13 C NMR-based dereplication method, resulting in the identification of twenty-six compounds. The dereplication process was completed by purification of some unknown or minor compounds of the n-BuOH fraction. Three new glycosylated flavonoids, namely kaempferol-3-O-β-D-glucopyranosyl-7-O-β-Dglucopyranosyl-(1→3)-α-L-rhamnopyranoside (1), isorhamnetin-3-O-β-D-glucopyranosyl-7-O-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranoside (2) and quercetin-3-O-β-Dglucopyranosyl-7,4'-O-α-L-dirhamnopyranoside (3), together with twelve known compounds (4 -15) were isolated. Their structures were elucidated by spectroscopic methods including NMR, HR-ESI-MS and UV. The antioxidant activity of fractions and isolated compounds were evaluated using DPPH and hydroxyl radical scavenging and CUPRAC assays. In parallel, their inhibitory properties against mushroom tyrosinase and human neutrophil elastase enzymes were assessed. Three quercetin glycosides exhibited a significant radicalscavenging activity and two flavonoids showed a moderate elastase inhibitory activity.