Direct spectrophotometric determination of quercetin content in onions (Allium cepa L.) was investigated as a possible alternative to high-performance liquid chromatography (HPLC) analysis. Quercetin content in five onion varieties was monitored at 362 nm and quantified using simple spectrophotometric and HPLC methods. HPLC revealed that 3,4'-Qdg and 4'-Qmg comprised up to 93% of total flavonol...

C affeoyltartronic acid and other eleven phenolic com pounds were identified in the M eO H extract o f Chondrilla juncea: the flavonoids luteolin, luteolin-7-glucoside, luteolin-7-galactosylglucuronide and quercetin-3-galactoside; the phenolic acids protocatechuic, caffeic, chlorogenic, isochlorogenic and isoferulic and the coum arins cichoriin and aesculetin. The taxonom ­ ic im plications o f...

While the phytochemical composition of lentil (Lens culinaris) seeds is well described in scientific literature, there is very little available data about secondary metabolites from lentil leaves and stems. Our research reveals that the aerial parts of lentil are a rich source of flavonoids. Six kaempferol and twelve quercetin glycosides were isolated, their structures were elucidated using NMR...

Anaerobic liquid dairy digestate is a by-product of waste anaerobic digestion from operations and associated with environmental risks if not handled properly, particularly nutrient leaching losses, water contaminations, greenhouse gas emissions. We tested the applications anerobic (AD) as biofertilizer source in vegetable production to integrate food industry management for sustainable environm...

Croton species are used in folk medicine in the management of infections, inflammation and oxidative stress-related diseases. In order to isolate, characterize and evaluate the bioactive constituents of Croton menyharthii Pax leaf extracts, repeated column fractionation of the ethyl acetate fraction from a 20% aqueous methanol crude extract afforded three flavonols identified by NMR (1D and 2D)...

Four antibacterial compounds were isolated from leaves of guava (Psidium guajava L.), and the structures of these compounds were established on the basis of chemical and spectroscopic evidence. Two new flavonoid glycosides, morin-3-O-alpha-L-lyxopyranoside and morin-3-O-alpha-L-arabopyranoside, and two known flavonoids, guaijavarin and quercetin, were identified. The minimum inhibition concentr...

The aim of the present study was to compare the ability of the myricetin and quercetin to modulate the oxidative DNA damage induced by 2-amino-3, 8-dimethylimidazo [4,5-f] quinoxaline (8-MeIQx), 2-amino-3, 4, 8-trimethylimidazo [4, 5-f]-quinoxaline (4,8-diMeIQx) and 2-amino-1-methyl-6-phenyl-imidazo [4,5-b] pyridine (PhIP), in human hepatoma cells. DNA damage (strand breaks and oxidized purines...

Quercetin is one of the most abundant polyphenolic flavonoids found in fruits and vegetables and has anti-oxidative and anti-obesity effects. Because the small intestine is a major absorptive organ of dietary nutrients, it is likely that highly concentrated food constituents, including polyphenols, are present in the small intestinal epithelial cells, suggesting that food factors may have a pro...

Background and objectives: Marrubium parviflorum Fisch. & C.A.Mey. (Lamiaceae) is a medicinal plant with documented antioxidant and analgesic effects distributed in Iran and Turkey. In the present study, the aerial parts of this species were subjected to phytochemical analysis, as well as antioxidant activity assays. Methods: Antioxidant activity of th...

Activity-guided isolation of 80% acetone extract of Cornus alba, which is traditionally used as an anti-inflammatory, hemostatic and diuretic in Korea, yielded one novel compound, tentatively designated cornusiin H (13), together with 12 known compounds. The known compounds included four flavonoids (catechin (1), quercetin-3-O-β-D-glucuronide (2), quercetin-3-O-β-D-glucopyranoside (3), kaempfer...