Essential Oils and Supercritical CO2 Extracts of Arctic Angelica (Angelica archangelica L.), Marsh Labrador Tea (Rhododendron tomentosum) and Common Tansy (Tanacetum vulgare)—Chemical Compositions and Antimicrobial Activities

Traditionally, arctic Finnish Angelica (Angelica archangelica L.), marsh Labrador tea (Rhododendron tomentosum, syn. Ledum palustre) and common tansy (Tanacetum vulgare) have been used as medicinal herbs in folklore medicine. However, these underutilised plants are a source of, e.g., oil-based compounds, which could benefit many modern applications implemented by the green chemistry extraction methods, as well. We extracted Angelica, marsh Labrador tea and common tansy by non-toxic and recyclable extraction methods, i.e., hydrodistillation and supercritical carbon dioxide (scCO2) extraction; characterised the essential oils (EOs) and scCO2 extracts by combination of gas chromatography and mass spectrometry (GC-MS), and in addition, analysed the antimicrobial properties. As expected for Angelica root and common tansy inflorescence, the scCO2 extraction method produced less amount of volatile compounds compared to hydrodistillation. On the other hand, more coumarins, alkanes, fatty alcohols and fatty acids were obtained. Additionally, sesquiterpenoids palustrol and ledol were predominant compounds in both marsh Labrador tea EO and scCO2 extract. According to our results, however, all the EOs and scCO2 extracts showed broad spectrum of antimicrobial activities against the selected microbes, but the effects were extract-specific. The strongest and broadest antimicrobial activities were performed by marsh Labrador tea scCO2 extract, which showed extremely strong effect on Staphylococcusaureus subsp. aureus and strong effect on Candida albicans.

An update to the species list of vascular plants of the spontaneous flora of the Left Bank Forest-Steppe of Ukraine

Data on findings of seven species of vascular plants that are new records for the spontaneous flora of the Left Bank Forest-Steppe zone of Ukraine are presented. Four species (Artemisia umbrosa, Sedum album, Ribes aureum, and Prunus tomentosa) are alien plants completely naturalized in the studied area; other three species are treated by author as representatives of the indigenous fraction (Cerastium kioviense, Rhododendron tomentosum, and Vicia lathyroides). Cerastium kioviense and V. lathyroides are considered not rare species in the studied region but rather overlooked by botanists due to their early flowering period. Four species (A. umbrosa, C. kioviense, R. aureum, and P. tomentosa) were for the first time found in Poltava Region, two species (R. aureum, P. tomentosa) – in Kharkiv Region, and one (V. lathyroides) – in Kyiv Region. For all reported species, lists of their localities, places of original descriptions and nomenclatural types are indicated. The species name Prunus tomentosa is lectotypified.

Review: Marsh rosemary (Rhododendron tomentosum Harmaja (ex Ledum palustre Linn) growing in Lithuania) essential oils and their properties

The paper reviews already (in the past fifteen years) published data from research articles on essential oils (EOs) and their biological properties (such as antioxidant, antifungal, anti-inflammatory and toxic activity) of marsh rosemary (Rhododendron tomentosum (Stokes) Harmaja (ex Ledum palustre Linnaeus, Ericaceae Juss.) growing wild in Lithuania. Rh. tomentosum is a perennial woody shrub (up to 1 m in height) with evergreen leaves and small white or white-pink sticky flowers grouped in racemes. The plant emits a strong specific smell that affects the central nervous system, and may cause nausea, headache or aggressive behaviour to some people. Only one species of the plant (ex L. palustre var. palustre) grows in Lithuania, mainly forming colonies in limited areas over all the territory. Marsh rosemary are widely used in folk medicine and homeopathy for treatment of various sickness, externally and internally as well. Most applications of Rh. tomentosum and pharmacological properties have been validated by scientific researches. In Lithuania, the plant is used for healing rheumatism, different pains, insect bites, eczema and other skin problems, infections, bronchitis, asthma, cold, tuberculosis, to block bleeding, etc. Rhododendron tomentosum H. (ex Ledum palustre L.) plants, the essential oils (EOs) of which are already investigated, were collected mostly in the Eastern part of the country (Rokiškis, Utena, Vilnius and Šalčininkai districts). Monoterpene hydrocarbons, p-cymene, myrcene and limonene, bicyclic monoterpenoid ascaridole and oxygenated sesquiterpenes, ledol, palustrol and cyclocolorenone isomers, were found to be principal compounds in the investigated EOs. Some oils contained appreciable quantities of heterocyclic compound lepalol. Most of the oils could be attributed to the ledol+palustrol or ledol+palustrol+ascaridole chemotype. Antifungal activity of Rh. tomentosum EOs was evaluated by several different techniques: against Penicillium cyclopium Westling, Trichoderma harzianum Rifai and Candida parapsilosis using an agar diffusion method; and amperometricaly, using Saccharomyces cerevisiae yeast-modified electrodes. Anti-inflammatory activity of Lithuanian marsh rosemary EOs has been revealed by subcutaneous carrageenan injection-induced hind paw oedema tests. However, antioxidant activity (tests using ABTS˙+, DPPH˙ and TROLOX) and toxic properties (against brine shrimp (Artemia sera) larvae) of Rh. tomentosum EOs were summarized.