Phytochemical study of Stachys sylvatica (Lamiaceae) aerial parts

In this article, the first complete phytochemical study of Stachys sylvatica (Lamiaceae) aerial parts, collected in Tuscan-Emilian Apennine, is reported. Twenty-three known compounds were isolated from the chloroform, chloroform-methanol 9:1 and methanol extracts; they were subsequently characterized by means of one- and two-dimensional nuclear magnetic resonance spectroscopy (1D- and 2D-NMR) and mass spectrometry as six simple phenolic derivatives (chlorogenic acid (1), caffeic acid (2), p-coumaric acid methyl ester (3), niduloic acid (4), hydroxytyrosol (5), tyrosol (6)), one glycosylated aliphatic alcohol (ebracteatoside B (7)), six glycosylated phenylpropanoids (decaffeoyl verbascoside (8), lavandulifolioside (9), betanyoside F (10), verbascoside (11), isoacteoside (12), cystanoside D (13)), four flavonoids (stachyspinoside (14), chrysoeriol 7-O-beta-D-glucopyranoside (15), naringenin 7-O-(6''-E + Z-p-coumaroyl)-beta-D-glucopyranoside (16), apigenin 7-O-(6''-E + Z-p-coumaroyl)-beta-D-glucopyranoside (17)), three lignans (syringaresinol 4'-O-beta-D-glucopyranoside (18), pinoresinol 4-O-beta-D-glucopyranoside (19), 2-episesaminol 2-O-beta-D-glucopyranoside (20)) and three ionones (loliolide (21), vomifoliol (22), (3S,5R,6R,7E,9R)-3,5,6,9-tetrahydroxy-7-megastigmene (23)). In addition, a further phenolic derivative (ethyl caffeate (b)) and four carboxylic acids (azelaic acid (a), trihydroxyoctadecadienoic acid (c), trihydroxyoctadecenoic acid (d) and dihydroxydodecadienoic acid (e)) have been tentatively identified by ultra-high performance liquid chromatography coupled to an electrospray ionization source high-resolution Orbitrap mass spectrometer (UHPLC-ESI-HR-Orbitrap/MS). Chemosystematic relationships between S. sylvatica and other related species were highlighted.

Automated summary

This article reports the first complete phytochemical study of Stachys sylvatica aerial parts, including the isolation and characterization of 23 known compounds. The compounds were identified using various analytical techniques, including nuclear magnetic resonance spectroscopy and mass spectrometry. The study also tentatively identified an additional phenolic derivative and four carboxylic acids. The chemosystematic relationships between S. sylvatica and related species were highlighted.