Hieracium pilosella L. (Asteraceae) is a well-known plant used in ethno-medicine as its inflorescences are particularly rich in beneficial polyphenolics. This research aimed to elucidate the structure of a new flavone glycoside isolated from the inflorescences of Hieracium pilosella and evaluate its antioxidant, antimicrobial and antiproliferative activities. The chromatographic methods were successfully applied to isolate the new flavonoid. Its structure was determined by subsequent UV, NMR and MS experiments and identified as isoetin 4′-O-β-D-glucopyranoside. Free radical scavenging capacity was examined by measuring the scavenging activity of the new isoetin derivative on 2,2-diphenyl-1-picrylhydrazyl (DPPH). The compound was also screened for spectrum of antimicrobial activity using the agar well diffusion method. Minimum inhibitory concentration (MIC) for Pseudomonas aeruginosa ATCC 9027 was performed by the micro-dilution broth method. The antiproliferative effect of tested glycoside was assessed in two human tumor cell lines derived from lung (A549) and colon (HT-29) carcinoma and cell proliferation was determined by means of MTT method. The tested compound showed high antiradical activity, reducing the DPPH? with EC50 7.9 μM (3.7 µg/ml) and exhibited narrow antimicrobial spectrum among tested microorganisms. The compound was active against Pseudomonas aeruginosa ATCC 9027 (MIC 125 μg/ml) which is prone to causing infections that are difficult to treat due to it developing extremely rapid antibiotic resistance. In the antiproliferative studies, cell proliferation of the colon (HT-29) carcinoma cell line was significantly decreased after exposure to the compound. The results indicate that isoetin 4′-O-β-D-glucopyranoside possesses antioxidant capacity and very promising antibacterial activity and could have uses as an effective antipseudomonal agent as well a antiproliferative agent.
Fractions of triterpenoids have been isolated from herb, inflorescences, and rhizomes with roots of Hieracium pilosella by typical extraction with petroleum ether. The fraction from inflorescences was investigated using GC-MS techniques. The occurrence of alpha- and beta-amyrin, taraxerol, taraxasterol, and fern-7en-3beta-ol has been observed. Quantitative analysis was also performed and taraxasterol is distinctly predominant in this triterpenoid fraction. Thin-layer chromatography on silica gel was performed on all the investigated fractions and additionally revealed the occurrence of lupeol and psi-taraxasterol in vestigial quantities. All of the triterpenoid components are reported for the first time in the investigated plant.
The folowing lichen acids were isolated from <i>Ramalina fraxinea</i> (L.) Ach. thallus: usnic, obtusatic and sekkikaic, as well as d-arabitol and three mucilage and amine fractions. In the mucilage hydrolysates glucose, galactose, glucosamine, arabinose, xylose, rhamnose and glucuronic acid were found. The following amines were discovered chromatographically: choline, betaine, histamine, acetyl-choline and (β-phenylethylamine; amino acids: aspartic, glutamic, γ-aminobutyric, serine, threonine, alanine, proline, moreover d-mannitol and free arabinose and glucose.
Vitexin, orientin, isoorientin, luteolin and apigenin were isolated from the herb, <em>Tragopogon orientnlis</em> L. The occurrence of quercetin and the phenolic acids: chlorogenic, homoprotoca-techuic, protocatechuic, caffeic, gentysic, p-hydroxybenzoic, m-hydroxybenzoic o-hydroxyphenylacetic, p-hydroxyphenylacetic, p-cumaric, syringic, vanillic, ferulic and salicylic, and of the sugars: glucose, fructose and sucrose was demonstrated chromatographically.
Phenolic acids were identified in the leaves of 23 species of native roses and their quantitative proportions were determined by the method of two-dimensional paper chromatography. The common occurrence of ellagic and gallic acid in roses was confirmed and so was the regular presence of protocatechuic, caffeic, gentisic, p-hydroxybenzoic, p-hydroxyphenylacetic, p-cumaric, syringic, vanillic, ferulic and salicylic acids. A small amount of isoferulic acid was noted only in <i>Rosa gizellae</i> Borb. and <i>R. eglanteria</i> L. var. <i>comosa</i> (Ripart) Du Mortier. Homoprotocatechuic acid was revealed only in the species of the <i>Rosa rubiginosa</i> and <i>Rosa tomentosa</i> groups from the <i>Caninae </i>section. The taxonomically limited occurrence of some phenolic acids points to the systematic differentiating value of the latter within one genus.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.