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Leonurus cardiaca L., also known as motherwort, is a plant native from central Europe that it is spread in different temperate countries around the world. The plant has been described to exert several beneficial properties and it is presently used in infusions, decoctions, syrups and tinctures, as well as an ingredient of pharmaceutical formulations. Yet, the plant phenolics, which are frequently associated to the claimed health benefits of Leonurus cardiaca L., are not fully clarified. This topic is focused in the present work. For that, an extract of the aerial parts of the plant was obtained with aqueous ethanolic solution (80%) and it was further purified onto SPE C18-E cartridges. The resulting purified phenolic extract was analyzed by HPLC-DAD and ESI-MSn techniques, for phenolic identification and quantification. Accordingly, phenolic compounds in Leonurus cardiaca L. purified ethanolic extract accounted for 15 mg/g of dry plant (500 ± 49 mg/g of extract). Phenylethanoid glycosides were the most prevalent phenolics with lavandulifolioside and verbascoside representing 50% and 27% of its total quantified phenolic compounds, respectively. Additionally, the present study allowed the identification and quantification of leucoseptoside A and leonoside B for the first time in Leonurus cardiaca L., which together, accounted for 11% of the quantified phenolics. Besides phenylethanoid glycosides, the Leonurus cardiaca L. ethanolic extract also contained flavonoids (10%) and caffeic acid derivatives, albeit the latter were only present in vestigial amounts. With the exception of luteolin-7-O-rutinoside, all the remaining flavonoids were glycosidic quercetin derivatives, which include the isoquercitrin, rutin, rutin-O-glucoside and quercetin-3-O-sophoroside. Possible association of the major phenolics herein identified with specific health benefits of the plant are under investigation.

Lamium album L., a plant commonly known as white dead nettle, has been used in folk medicine in the treatment of several ailments. Some of their benefitial properties are closely related to its phenolic content, however the exact polyphenolic composition is far from being understood. In this context, the present work aims to determine the phenolic composition of an ethanolic extract of L. album using high performance liquid chromatography with diode array detection, electrospray mass spectrometry and nuclear magnetic resonance techniques. The phenolic extract of L. album was mainly composed by the phenylethanoid verbascoside and its isomer isoverbascoside. Still, it also contained significant amounts of isoscutellarein derivatives, which were herein detected for the first time in the genus Lamium. As isoscutellarein derivatives appear as major components of Lamium Album L., it is feasible that they can be correlated to the beneficial human health properties of this plant.

Cytisus multiflorus is a well known Mediterranean plant presenting diuretic, anti-inflammatory, anti-hypertension and antidiabetic properties [1]. The high phenolic content of C. multiflorus is frequently associated to its health beneficial properties, however its phenolic composition remains unclear. In this work, the phenolic profile of an extract of C. multiflorus flowers was elucidated. After extraction with an aqueous ethanolic solution (80%), the enrich phenolic extract was analyzed by high performance liquid chromatography with diode array detection, electrospray mass spectrometry [2] and nuclear magnetic resonance techniques. The extract of C. multiflorus was mainly composed with chrysin-7-O-β-D-glycopyranoside (MW 416) that accounted for 15.9±2.3 mg/g of dried plant. It also contained considerable amounts of rutin (4.5±0.7 mg/g), a dihydroxyflavone isomer of chrysin (7.0±1.3 mg/g), 2′′-O-pentosyl-6-C-hexosyl-luteolin (3.3±0.5 mg/g), 2′′-O-pentosyl-8-C-hexosyl-luteolin (3.5 ± 0.3 mg/g) and 6′′-O-(3-hydroxy-3-methylglutaroyl)-2′′-O-pentosyl-C-hexosyl-apigenin (3.6±0.7 mg/g), which are not commonly found in the Fabaceae family. Other unusual phenolic compounds found in minor amounts in the ethanolic extract of C. multiflorus flowers comprised the flavones 2′′-O-pentosyl-6-C-hexosyl-apigenin, 2′′-O-pentosyl-8-C-hexosyl-apigenin and 6′′-O-(3-hydroxy-3-methylglutaroyl)-2′′-O-pentosyl-C-hexosyl-luteolin. The present work emerges as an important contribution for the phenolic characterization of Cytisus genus and of Fabaceae family.

The main aim of this work is to determine the phenolic composition of a Lamium album L. purified extract, in order to contribute for the chemical characterization of this plant. Moreover, it also intends to emphasize its antioxidant properties. As established by HPLC-DAD and ESI-MSn combined analysis, verbascoside was the major phenolic constituent of Lamium album L. purified extract, as previously described by other authors [1]. Still, we could also detect, for the first time in Lamium genus, significant amounts of isobervascoside and of isoscutellarein derivatives. As confirmed by NMR analysis, the major isoscutellarein derivative in Lamium album L. purified extract was the isoscutellarein-7-O-(6-O-acetyl-β-allosyl)(1→2)-β-glucoside, but isoscutellarein-7-O-allosyl(1→2)glucoside and of O-methyl derivatives of these two compounds were also present in considerable amounts. Aditionally, the extract showed good antioxidant activities in in vitro experiments. Overall, the present study contributes for the chemical and biological characterization of L. album L.

Cytisus Desf. (Fabaceae) is a diversified genus enclosing approximately sixty species, which are particularly found around the Mediterranean Sea. Many plants of this genus exhibit bioactive properties such as diuretic, hypnotic, anxiolytic, antiparasitic, antidiabetic and antioxidant [1] and, in particular the latter, has been closely associated to the high content in flavonoids [2]. The present work aims to contribute to the knowledge of Cytisus Desf. chemical composition, through the identification of new flavonoids in that genus. The compounds in focus were detected in ethanolic extracts of Cytisus multiflorus flowers by means of HPLC-DAD, ESI-MS and MSn analyses. These included the two isomers 2′′-O-pentosyl-6-C-hexosyl-luteolin and 2′′-O-pentosyl-8-C-hexosyl-luteolin (MW 580 Da), the two isomers 2′′-O-pentosyl-6-C-hexosyl-apigenin and 2′′-O-pentosyl-8-C-hexosyl-apigenin (MW 564 Da), the 6′′-O-(3-hydroxy-3-methylglutaroyl)-2′′-O-pentosyl-C-hexosyl-luteolin (MW 724 Da) and the 6′′-O-(3-hydroxy-3-methylglutaroyl)-2′′-O-pentosyl-C-hexosyl-apigenin (MW 708 Da). Attending that half of the these compounds were herein described for first time in Fabaceae, overall, the present work is a valuable contribution for the phenolic elucidation of Cytisus genus as well as the Fabaceae family.

Thymus species are well known as medicinal plants because of their biological and pharmacological properties, which include anti-asthmatic, anti-septic, antimicrobial and antioxidant. It is believed that part of these beneficial effects are due to the volatile constituents of Thymus, and thus, their essential oil composition has been the focus of many investigations. In contrast, there is only a limited number of data on the composition of other bioactive phytochemicals of Thymus and their potential biological effects. The present study aims to elucidate the phenolic composition of an ethanolic extract of Thymus citriodorus, as well as to determine its antioxidant capacity. The ethanolic extract was obtained by solubilisation of the defatted-dried plant with aqueous ethanol (80%) for twenty minutes, in a total number of five extractions. The total phenolic compounds in the extract accounted for 139±14 mg/g, as expressed as gallic acid equivalents. Further analysis of the ethanolic extract by high performance liquid chromatography (HPLC) and electrospray mass spectrometry in the negative mode allowed to conclude that its main phenolic components were rosmarinic acid (14.0±0.8 μg/mg extract), luteolin-7-O-glucoside (11±2 μg/mg extract), an apigenin derivative (9±2 μg/mg extract), eriodictyol-O-glucoside (5.5±0.7 μg/mg extract) and naringenin-O-glucoside (1.6±0.1 μg/mg extract). Moreover, the ethanolic extract of Thymus citriodorus exhibited a high antioxidative capacity, with EC50 values of 0.32±0.05 mg/ml for the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging potential and EC50 values of 0.8±0.2 mg/ml for the reducing power. Overall, these results suggest that Thymus citriodorus can be a good source of natural antioxidants.