Plants are rich in secondary metabolites, which often useful as a relevant source of nutraceuticals. Quercetin (QUE) is flavonol aglycone able to bind Transthyretin (TTR), plasma protein that under pathological conditions can lose its native structure leading fibrils formation and amyloid diseases onset. Here, the dual nature five quercetin 3-O-glycosylated derivatives, isolated from different ...

A study of the effects of different steroids on germination and tube growth of tobacco pollen (Nicotiana tabacum L. cv Petit Havana SR1) matured in vitro is presented. Application of the mammalian steroid sex hormones (testosterone, progesterone, and estradiol) resulted in a stimulation of pollen germination and tube elongation. The presence of both steroids and flavonols in the germination med...

Quercetin a flavonoid to be a member of a group of flavonols is universally consumed in the human diet and responsibly to give the color to various fruits and vegetables [1]. Mainly occur in the form of glycosides, but their other derivative have been identified [2-5]. This paper presents some recent advances regarding quercetin structure, derivatives, sources and their medicinal benefits with ...

Cassia auriculata is widely distributed even in poor soil in Sri Lanka, India, Burma and cultivated in tropics. Based on Physical and Chemical methods, the flower of C. auriculata was found to contain a flavonol glycoside 5-O-methylquercetin 7-O-glucoside. The 50% acetone extract of the flower of C. auriculata showed marked anti-inflammatory activity (56%) in carrageenin induced oedema in rats.

Leaf glands of Ceanothus species excrete a lipophilic material that contains a variety of flavonoids. Most of these are aglycones, but some glycosides were also observed. Seven out of eight species exhibit flavonols, whereas flavones are excreted by only one species. Four species produce flavanones and dihydroflavonols; one excretes a remarkable quantity of flavonol glycosides. The exudate flav...

The antioxidants such as polyphenols, especially flavonols, present in large quantitites in cocoa, cause vasodilation, modulate inflammatory markers and cardiovascular health, and possess a range of protective cardiovascular effects. On the other hand, overconsumption of chocolate can lead to tachyarrhythmias, supraventricular tachycardia, atrial fibrillation, ventricular tachycardia and ventri...

• Numerous studies have reported the protective cardiovascular effects of polyphenolic antioxidants. It is estimated that flavonoids contribute approximately two-thirds of all the polyphenols ingested, whereas phenolic acids contribute the remaining one third. Red wine is a very rich source of flavonoids, particularly the class called flavanols. Other important sources of flavonoids are apples,...

Chokeberry and elderberry fruits are rich sources of polyphenols, the compounds with significant antiradical and chelating properties. They are studied intensively because of beneficial effects on human health. In this study, three fractions enriched with different classes of polyphenols were isolated from chokeberry and elderberry to study their antiradical activity by DPPH test. The first fra...

Demand for and availability of blueberries has increased substantially over recent years, driven in part by their health-promoting properties. Three blueberry varieties ('Rocío', V2, and V3) were grown under two cultivation systems (open-field and plastic tunnels) and subjected to two irrigations regimes (100% and 80% of crop evapotranspiration) in two consecutive years (2011-2012). They were e...

In this paper the excited state proton transfer (ESPT) of isolated 3-hydroxychromone (3-HC), the prototype of the flavonols, is investigated for the first time by combined IR/UV spectroscopy in molecular beam experiments. The IR/UV investigations are performed both for the electronically excited and electronic ground state indicating a spectral overlap of transitions of the 3-HC monomer and clu...