Asplenioideae Species as a Reservoir of Volatile Organic Compounds with Potential Therapeutic Properties.

Twelve French Asplenioideae ferns (genera Asplenium and subgenera Ceterach and Phyllitis) were investigated for the first time for volatile organic compounds (VOC) using GC-MS. Sixty-two VOC biosynthesized from the lipidic, shikimic, terpenic and carotenoid pathways were identified. Several VOC profiles can be highlighted from Asplenium jahandiezii and A. xalternifolium with exclusively lipidic derivatives to A. onopteris with an equal ratio of lipidic/shikimic compounds. Very few terpenes as caryophyllene derivatives were identified, but only in A. obovatum subsp. bilotii. The main odorous lipidic derivatives were (E)-2-decenal (waxy and fatty odor), nonanal (aldehydic and waxy odor with a fresh green nuance), (E)-2-heptenal (green odor with a fatty note) and 1-octen-3-ol (mushroom-like odor), reported for all species. A few VOC are present in several species in high content, i.e., 9-oxononanoic acid used as a precursor for biopolymers (19% in A. jahandiezii), 4-hydroxyacetophenone with a sweet and heavy floral odor (17.1% in A. onopteris), and 4-hydroxybenzoic acid used as a precursor in the synthesis of parabens (11.3% in A. foreziense). Most of the identified compounds have pharmacological activities, i.e., octanoic acid as antimicrobial, in particular against Salmonellas, with fatty and waxy odor (41.1% in A. petrarchae), tetradecanoic acid with trypanocidal activity (13.3% in A. obovatum subsp. bilotii), 4-hydroxybenzoic acid (8.7% in A. onopteris) with antimicrobial and anti-aging effects, 3,4-dihydroxybenzaldehyde as an inhibitor of growth of human cancer cells (6.7% in Ceterach officinarum), and phenylacetic acid with antifungal and antibacterial activities (5.8% in A. onopteris). Propionylfilicinic acid was identified in the twelve species. The broad spectrum of odorous and bioactive VOC identified from the Asplenium, Ceterach and Phyllitis species are indeed of great interest to the cosmetic and food industries.

Volatile organic compounds of six French Dryopteris species: natural odorous and bioactive resources.

Aerial parts of six Dryopteris species collected in France were investigated for volatile organic compounds (VOC) for the first time. Fifty-three biosynthesized VOC from the shikimic, lipidic and terpenic pathways were identified using gas chromatography/mass spectrometry. Many bioactive polyketide compounds as filicinic derivatives (from 8.5 to 23.5%) and phloroglucinol derivatives (from 8.2 to 53.8%) with various pharmacological activities were detected in high amount from five analysed Dryopteris species, in particular D. oreades and D. borreri, i.e., propionylfilicinic acid (> 10% in D. affinis and D. ardechensis) and 2,6-dihydroxy-4-methoxy-3-methylbutyrophenone (aspidinol) (19.1% and 14.6% in D. oreades and D. borreri, respectively). Several terpenic derivatives with a low odor threshold were identified, i.e., carota-5,8-diene (from 2.5 to 18.4%: floral, woody or fresh bark note), (E)-nerolidol (> 10% for D. borreri and D. cambrensis; floral or woody odor), alpha-selinene (> 7% for D. ardechensis; woody-spicy odor), and aristolene (12.8% in D. affinis; flower, sweet odor). The main isoprenoid derivatives were 4-hydroxy-5,6-epoxyionol, 3-oxo-alpha-ionol and 4-oxo-7,8-dihydro-beta-ionone (essentially in D. remota), whereas the main aromatic compound was 4-hydroxy-3-methoxyacetophenone (20.6% and 12.6% in D. cambrensis and D. borreri, respectively) and the main lipid derivative was 1-octen-3-ol with a mushroom-like odor (from 0.4 to 8.3%). Dryopteris species resources are of great interest as a reservoir of odorous and bioactive compounds.

Volatile composition of six horsetails: prospects and perspectives.

Six horsetails were investigated for volatile organic compounds (VOC) by GC-MS using organic solvent extraction. Seventy-five VOC biosynthesized from the shikimic, lipidic and terpenic pathways including isoprenoid derivatives were detected from these putative natural resources. E. palustre var. americana contained mainly lipidic derivatives, i.e., 1-octen-3-ol (mushroom-like odor), (E)-2-hexenoic acid (fruity odor) and (E)-2-hexenal (green odor). Many isoprenoid flavour precursors, i.e., 3-oxo-alpha-ionol (spicy odor) and (E,E)-pseudoionone (balsamic odor), as well as odorous benzenic derivatives, i.e, phenylethanal (hyacinth, lilac note) and 2-phenylethanol (rose odor) contributed to the odor of E. arvense. The volatile pattern of E. telmateia is dominated by high amounts of isoprenoids and benzenic derivatives. The complex volatile profiles of E. hyemale and E. ramosissimum are based on ferulic acid isomers, along with either (E)-2-heptenal (green vegetable-like odor) or 4-vinylguaiacol (spicy clove smoky odor) for E. hyemale and E. ramosissimum, respectively. The broad spectrum of E. scirpioides shows the lowest VOC content with high amount of isoprenoids (46.9%), mainly ionone derivatives. Equisetum resources are of great interest as bioactive litter and new potential functional feed ingredients.

Volatiles of French ferns and "fougère" scent in perfumery.

Six French ferns were investigated for volatile organic compounds (VOC) by GC-MS using organic solvent extraction. Seventy-seven VOC biosynthesized from the shikimic, lipidic and terpenic pathways, including isoprenoid derivatives, were identified from these putative natural resources. Asplenium trichomanes subsp. trichomanes contained mainly polyketides with an oily or waxy odor. (E)-2-Hexenal and (Z)-3-hexenol, responsible for the "green odor", were found in high contents in Polystichum setiferum, Dryopteris dilatata and Phegopteris connectilis. In the last, 7.4% of coumarin with a cut hay scent was highlighted from the volatile fraction. (E)-3-Hexenoic acid and (E)-2-hexenoic acid, both with herbal and fruity notes, were identified in Gymnocarpium dryopteris and Pteridium aquilinum. 1-Octen-3-ol, well-known for its mushroom-like odor, was abundant in all analyzed French ferns. While the "fougère" fragrance is claimed by the perfumers to be a fantasy scent, coumarin, (E)-2-hexenal, (Z)-3-hexenol and 1-octen-3-ol are the main odorous components of the perfumes belonging to the fougère accord family. This suggests that the fougère scent from the perfumers' imagination is a natural fragrance.

Biodiversity of volatile organic compounds from five French ferns.

Five French ferns belonging to different families were investigated for volatile organic compounds (VOC) by GC-MS using organic solvent extraction. Fifty-five VOC biosynthesized from the shikimic, lipidic and terpenic pathways including monoterpenes, sesquiterpenes and carotenoid-type compounds were identified. The main volatile compound of Adiantum capillus-veneris L. (Pteridaceae) was (E)-2-decenal with a plastic or "stink bug" odor. The volatile profiles of Athyrium filix-femina (L.) Roth (Woodsiaceae) and Blechnum spicant (L.) Roth (Blechnaceae) showed similarities, with small amounts of isoprenoids and the same main volatile compounds, i.e., 2-phenylethanal (odor of lilac and hyacinth) and 1-octen-3-ol (mushroom-like odor). The main volatile compound of Dryopteris filix-mas (L.) Schott (Dryopteridaceae) was (E)-nerolidol with a woody or fresh bark note. Polyketides, as acylfilicinic acids, were mainly identified in this fern. Oreopteris limbosperma (Bellardi ex. All.) J. Holub (Thelypteridaceae), well-known for its lemon smell, contained the highest biodiversity of VOC. Eighty percent of the volatiles was issued from the terpenic pathway. The main volatiles were (E)-nerolidol, alpha-terpineol, beta-caryophyllene and other minor monoterpenes (for example, linalool, pinenes, limonene, and gamma-terpinen-7-al). It was also the fern with the highest number of carotenoid-type derivatives, which were identified in large amounts. Our results were of great interest underlying new industrial valorisation for ferns based on their broad spectrum of volatiles.