Secondary metabolites from Scrophularia canina L.

A re-examination of Scrophularia canina L. confirmed the presence of iridoid glucosides considered as chemotaxonomic markers for the Scrophulariaceae family, like aucubin, harpagide and 8-O-acetylharpagide, besides the further presence of 8-epiloganic acid, which is, indeed, considered the biogenetic precursor of iridoids normally found in Scrophulariaceae, and was recognised here for the first time in the studied species. Also verbascoside and (E)-phytol were evidenced for the first time in S. canina. The former compound is an almost ubiquitous glycosidic phenyl-ethanoid, which attains systematic importance when in co-occurrence with iridoids, and its taxonomical implications were discussed. The latter compound, even though it is omnipresent, is interestingly endowed with several biological activities, which may give an additional reason for the traditional uses of this plant.     

A new iridoid diglucoside from Harpagophytum procumbens

A new iridoid diglucoside has been isolated from an aqueous extract of Harpagophytum procumbens secondary roots, together with six known compounds. Its structure has been assigned as 6′-O-glucopyranosyl-8-O-trans-coumaroylharpagide by spectroscopic means.     

Secoiridoids and other chemotaxonomically relevant compounds in Pedicularis: phytochemical analysis and comparison of Pedicularis rostratocapitata Crantz and Pedicularis verticillata L. from Dolomites

We compared the respective metabolite patterns of two Pedicularis species from Dolomites. Seven phenylethanoid glycosides, i.e., verbascoside (1), echinacoside (2), angoroside A (3), cistantubuloside B1 (4), wiedemannioside C (5), campneoside II (11) and cistantubuloside C1 (12), together with several iridoid glucosides as aucubin (6), euphroside (7), monomelittoside (8), mussaenosidic acid (9) and 8-epiloganic acid (13) were identified. Pedicularis verticillata showed also the presence of greatly unexpected secoiridoids, ligustroside (14) and excelside B (15), very rare compounds in Lamiales. Both PhGs and iridoids are considered of taxonomical relevance in the Asteridae and their occurrence in Pedicularis was discussed. In particular, the exclusive presence of several compounds such as 8-epiloganic acid (13), campneoside II (11), cistantubuloside C1 (12), ligustroside (14) and excelside B (15) in Pedicularis rostratocapitata, and angoroside A (3), cistantubuloside B1 (4) and wiedemannioside C (5) in P. verticillata could be considered specific markers for the two botanical entities.     

Antioxidant and antiproliferative activity of Stachys glutinosa L. ethanol extract

Ethanol extracts of Stachys glutinosa L. (Lamiaceae) were investigated for antioxidative properties, as well as antiproliferative action on various cell lines. The antioxidant activities were investigated by ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulphonic acid) assay, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, β-carotene/linoleic acid assay, scavenging of hydrogen peroxide (horseradish peroxidase test), superoxide anion scavenging, and hypochlorous acid scavenging (taurine test). The antioxidant activity was reported as IC₅₀ and reveals antioxidant effects. Antiproliferative effects were measured in vitro on three cell lines: HepG2 (human hepatocarcinoma), MCF7 (breast human adenocarcinoma) and C2C12 (mouse myoblast) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The ethanol extract induced variations in cell viability on all cell lines tested. At 200 μg/mL, the effects on cell viability were ? 23%, ? 27% and ? 37%, respectively, for C2C12, MCF7 and HepG2.