quercetin-3-o-glucuronide and isoquercitrin

Flavonols play key roles in many plant defense mechanisms, consequently they are frequently investigated as stress sensitive factors in relation to several oxidative processes. It is well known that grapevine (Vitis vinifera L.) can synthesize various flavonol glycosides in the leaves, however, very little information is available regarding their distribution along the cane at different leaf levels. In this work, taking into consideration of leaf position, the main flavonol glycosides of a red grapevine cultivar (Cabernet Sauvignon) were profiled and quantified by HPLC-DAD analysis. It was found that amount of four flavonol glycosides, namely, quercetin-3-O-galactoside, quercetin-3-O-glucoside, kaempferol-3-O-glucoside and kaempferol-3-O-glucuronide decreased towards the shoot tip. Since leaf age also decreases towards the shoot tip, the obtained results suggest that these compounds continuously formed by leaf aging, resulting in their accumulation in the older leaves. In contrast, quercetin-3-O-glucuronide (predominant form) and quercetin-3-O-rutinoside were not accumulated significantly by aging. We also pointed out that grapevine boosted the flavonol biosynthesis in September, and flavonol profile differed significantly in the two seasons. Our results contribute to the better understanding of the role of flavonols in the antioxidant defense system of grapevine.

Topics: Chromatography, High Pressure Liquid; Flavonols; Fruit; Glucosides; Glucuronides; Glycosides; Kaempferols; Monosaccharides; Plant Leaves; Quercetin; Seasons; Vitis

Dried achene or anthocarpous accessory fruits of Rosa multiflora Thunb., Rosae fructus ("Eijitsu" in Japanese), have been used in clinical practice to improve constipation within traditional Japanese medicine. Recently, it has been claimed that the efficacy of this crude drug is decreasing, and multiflorin A, the purgative component, was not detected within the tested samples. In order to clarify the causes of this issue, we investigated Rosa section Synstylae (Rosaceae), including R. multiflora, growing in Japan and South Korea with a focus on the secondary metabolite, multiflorin A. We recognize that there are two chemotypes based on the presence (Type I) or absence (Type II) of multiflorin A. Type I contains quercitrin, multinoside A, multiflorin B, and multinoside A acetate as major index compounds. Type II contains hyperin, isoquercitrin, quercetin 3-O-glucuronide, and 3'-methoxy-isoquercitrin as the major index compounds. The chemotype of Rosa section Synstylae (Rosaceae) plants collected in Japan (excluding Tsushima Island) were all classified as Type I with exception of two species, R. luciae and R. sambucina. On the other hand, both Type I and Type II were detected within Rosae fructus obtained from R. multiflora collected in South Korea and Tsushima Island, Japan. The results indicate that Rosae fructus from R. multiflora (Type I) from Japan, excluding Tsushima Island, should be employed clinically, which we describe as purgative.

Topics: Chromones; Flavonols; Fruit; Glycosides; Japan; Medicine, Traditional; Phytochemicals; Quercetin; Republic of Korea; Rosa

Topics: Antioxidants; Biflavonoids; Catechin; Chromatography, High Pressure Liquid; Glutathione; HT29 Cells; Humans; Hydrogen Peroxide; Phenols; Plant Extracts; Polyphenols; Proanthocyanidins; Quercetin; Reactive Oxygen Species; Vitis

The traditional use of lotus leaves as an anti-inflammatory remedy is associated with the occurrence of phenolic compounds. In this study the first CE method for the analysis of all major phenolic constituents in Nelumbo nucifera leaves is presented. It permits the separation of nine relevant markers in less than 10 min. The optimized procedure was fully validated and then used to analyze diverse samples collected in Vietnam. They revealed significant qualitative and quantitative differences depending on growing area and season. Yet, in all of them, quercetin-3-O-β-D-glucuronide, hyperoside, and isoquercitrin were the most dominant flavonoids.

Topics: Electrophoresis, Capillary; Nelumbo; Phenols; Plant Leaves; Quercetin; Regression Analysis; Reproducibility of Results; Sensitivity and Specificity; Vietnam