The Effect of Extracts and Essential Oil from Invasive Solidago spp. and Fallopia japonica on Crop-Borne Fungi and Wheat Germination.

RESEARCH BACKGROUND: Many plant extracts and essential oils show antibacterial and antifungal activities, with potential to replace the use of synthetic fungicides. We used invasive alien plants goldenrod (Solidago spp.) and Japanese knotweed (Fallopia japonica) as source materials to determine their antifungal activities against seed-associated fungi from wheat grain (Alternaria alternata, Alternaria infectoria, Aspergillus flavus, Epicoccum nigrum and Fusarium poae). EXPERIMENTAL APPROACH: Aqueous and organic extracts (ethanol, methanol and acetone) were prepared from leaves and flowers of S. canadensis, S. gigantea and S. virgaurea, and leaves and rhizomes of F. japonica. Additionally, essential oils were distilled from Solidago flowers and leaves. The extracts and essential oils were tested as inhibitors of fungal growth in vitro. Solidago essential oils were tested also as antifungal agents for protection of wheat grain by determining its fungal infection and germination rate. RESULTS AND CONCLUSIONS: The extracts showed a wide spectrum of low to moderate antifungal activities, with those of Solidago spp. generally more effective than those of F. japonica, and organic extracts more effective than aqueous extracts. The essential oils from leaves and flowers had similar antifungal activity and whole shoots can be collected for their production. This study presents the systematic study of the composition of essential oils from flowers and leaves of three widely distributed Solidago spp. in Slovenia, with the major constituents of terpenes and terpenoids α-pinene, germacrene D and bornyl acetate. NOVELTY AND SCIENTIFIC CONTRIBUTION: The study presents the first use of Solidago spp. and Fallopia japonica extracts and essential oils against fungal strains isolated from wheat grain.

TLC densitometric method for screening of lycopsamine in comfrey root (Symphytum officinale L.) extracts using retrorsine as a reference compound.

Due to severe toxicity of pyrrolizidine alkaloids, their quantification in medicinal products is very important. The idea of this research was to use retrorsine as a surrogate reference compound instead of lycopsamine reference or lycopsamine isolated from comfrey. A method for the analysis of lycopsamine in extracts of comfrey roots was developed and validated, employing thin layer chromatography, derivatisation with Dann-Mattocks reagent followed by densitometric analysis. The new method showed linearity within 0.70 to 7.0 µg of lycopsamine per application of 10 µL of a solution. It has also been proven to be specific and precise (repeatability RSD 2-4 % within the plate). The method was successfully employed for quantification of lycopsamine in comfrey root and comfrey root medicinal products such as ointments.

The content of fagopyrin and polyphenols in common and tartary buckwheat sprouts.

Dried buckwheat herb is used in medicinal products whereas fresh green plant parts, especially sprouts, are consumed as a vegetable. The herb contains fagopyrins, which cause sensitivity to light after ingestion. The aim of this study was to investigate the impact of different growing conditions and the development phase on the content of fagopyrin and phenolic compounds in buckwheat sprouts. Total flavonoid and total phenol contents, fagopyrin content and antioxidant activity were determined spectrophotometrically. Fagopyrin and flavonoids were located almost exclusively in cotyledons. Based on a comparison to hypericin toxicity, the recommendable intake of buckwheat sprouts was estimated to be less than 40 g per day.

Improved method for isolation of lycopsamine from roots of comfrey (Symphytum officinale).

An improved method for the isolation and purification of pyrrolizidine alkaloids from comfrey (Symphytum officinale L.) roots was developed, introducing very fast, selective and ion residue-free reduction of N-oxides followed by ion-exchange chromatography giving a non-aqueous solution of alkaloids, from which solvents can be easily removed. With this procedure the use of large volumes of organic solvents, very slow reduction of N-oxides and input of additional impurities was avoided. Lycopsamine, which proved to be the major alkaloid, was additionally purified by preparative layer chromatography (PLC) and high performance liquid chromatography (HPLC). The identity of the alkaloid was confirmed by (I)H NMR spectroscopy and mass spectrometry.

Identification and quantification of aroma compounds of tartary buckwheat (Fagopyrum tataricum Gaertn.) and some of its milling fractions.

UNLABELLED: Tartary buckwheat (Fagopyrum tataricum) seeds have a strong aroma that characteristically differs from the aroma of common buckwheat (Fagopyrum esculentum). Its phytochemical background has only been recently investigated. The aim of this study was to identify and quantify individual compounds responsible for tartary buckwheat aroma. Volatiles from different samples (whole seed, flour, and husks) were extracted with simultaneous extraction and distillation by Likens-Nickerson apparatus and analyzed by GC-MS. A total of 48 compounds were quantified and their odor activity values (OAV) were calculated. OAV of 26 compounds was higher than 10; therefore, they significantly contribute to the overall tartary buckwheat aroma. The compounds with OAV > 500 were: (E,E)-2,4-decadienal, (E)-2-nonenal, 2-phenylethanol, (E,E)-2,4-nonadienal, hexanal, decanal, and nonanal. The most important difference from the aroma of common buckwheat is the absence of salicylaldehyde and presence of naphthalene. Salicylaldehyde could be proposed as a marker to detect contamination/adulteration of tartary buckwheat with common buckwheat. PRACTICAL APPLICATION: Buckwheat is becoming one of important alternative crops. Its products which are rich in proteins, fiber, vitamins, and antioxidants have been associated with healthy nutrition. Although tartary buckwheat is similar to more familiar common buckwheat, their characteristic aromas differ notably. This study expands recent research on aroma of tartary buckwheat tea to seed, flour, and husks, and suggests how products from different species of buckwheat can be distinguished by analysis of aroma compounds.

Screening of selected food and medicinal plant extracts for pancreatic lipase inhibition.

Lipids are important components in human nutrition; however, their increased intake contributes to the development of obesity and can lead to multiple long-term complications. Pancreatic lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) is a key enzyme for the absorption of dietary triglycerides. Interference with fat hydrolysis results in the reduced utilization of ingested lipids, therefore inhibition of lipases decreases fat absorption. Extracts from 106 species of medicinal plants, vegetables and fruits were screened for potential lipase inhibitory activity. p-Nitrophenylpalmitate and 5-bromo-4-chloro-3-indoxylpalmitate were used as substrates in an in vitro test with crude porcine pancreatic lipase. Bearberry (Arctostaphylos uva-ursi), garden pea (Pisum sativum), Norway spruce (Picea abies) and large-leaved lime (Tilia platyphyllos) extracts were the most active. Additionally, the activity of selected extracts with removed polyphenols was measured. Extracts of bearberry, garden pea and large-leaved lime are a promising source for developing functional foods or isolating active compounds.