Anthocyanins

Phenolics from grapes and wines can play a role against oxidation and development of atherosclerosis. Levels of phenolics, major catechins [(+)-catechin, (-)-epicatechin, procyanidin dimers B1, B2, B3, and B4], phenolic acids (gallic acid and caffeic acid), caftaric acid, malvidin-3-glucoside, peonidin-3-glucoside, and cyanidin-3-glucoside were quantified by HPLC with UV detection for 54 French varietal commercial wines taken from southern France to study the antioxidant capacity and the daily dietary intake of these compounds for the French population. The highest antioxidant capacity was obtained with red wines and ranged from 12.8 mmol/L (Grenache) to 25.2 mmol/L (Pinot Noir). For white wines, Chardonnay enriched in phenolics by special wine-making was found to have an antioxidant capacity of 13.8 mmol/L, comparable to red wine values. For red wines classified by vintages (1996-1999) antioxidant capacities were approximately 20 mmol/L and then decreased to 13.4 mmol/L for vintages 1995-1991. Sweet white wines have 1.7 times more antioxidant capacity (3.2 mmol/L) than dry white wines (1.91 mmol/L). On the basis of a still significant French wine consumption of 180 mL/day/person, the current daily intake of catechins (monomers and dimers B1, B2, B3, and B4) averaged 5 (dry white wine), 4.36 (sweet white wines), 7.70 (rosé wines), 31.98 (red wines), and 66.94 (dry white wine enriched in phenolic) mg/day/resident for the French population. Red wine, and particularly Pinot Noir, Egiodola, Syrah, Cabernet Sauvignon, and Merlot varieties, or Chardonnay enriched in phenolics during wine-making for white varieties contribute to a very significant catechin dietary intake.

Background:  Hyperglycemia and oxidative stress are hallmarks of diabetes mellitus (DM). Excessive oxidative stress is implicated in diabetic pathogenesis when endogenous antioxidants are defective.

Objective: The present study evaluates the effects of anthocyanins present in the petals of Hibiscus rosa- sinensis on oxidative stress and antioxidant status in streptozotocin-induced diabetic rats.

Materials and methods: Diabetes was induced in male Sprague-Dawley rats by a single intraperitoneal injection (30mg/kg) of streptozotocin. Hibiscus rosa sinensis anthocyanins (HA) extract (50 mg/kg body weight) orally administered to diabetic rats for 30 days. Results compared with diabetic rats provided with the standard drug metformin (150 mg/kg body weight).

Results: Altered levels of glucose, glycated hemoglobin, toxicity markers and lipid profile in serum were significantly modulated upon the administration of HA in diabetic rats. A supplementation of HA to diabetic rats reduced oxidative stress, as well as increased the levels of antioxidant enzymes in the liver. The present study demonstrates that HA has a protective effect on diabetic rats

Conclusion: The present study indicates that Hibiscus anthocyanin supplementation could protect diabetic rats' livers by protecting the hepatocytes from oxidative stress and increasing the antioxidant enzymes' activity. 

Keywords: Diabetes mellitus, Hibiscus rosa sinensis anthocyanins, Oxidative stress

In this study, the polyphenolic profile of 11 Morus alba fruits grown in the Vojvodina region was investigated. Ultra high performance liquid chromatography (UHPLC) coupled with Linear Trap Quadrupole and OrbiTrap mass analyzer, and UHPLC coupled with a diode array detector and a triple-quadrupole mass spectrometer were used for the identification and quantification of the polyphenols, respectively. A total of 14 hydroxycinnamic acid esters, 13 flavonol glycosides, and 14 anthocyanins were identified in the extracts with different distributions and contents according to the sampling. The total phenolic content ranged from 43.84 to 326.29 mg GAE/100g frozen fruit. The radical scavenging capacity (50.18-86.79%), metal chelating ability (0.21-8.15%), ferric ion reducing power (0.03-38.45 μM ascorbic acid) and superoxide anion radical scavenging activity (16.53-62.83%) were assessed. The findings indicated that mulberry polyphenolics may act as potent superoxide anion radical scavengers...

The novel anthocyanins, malvidin 3-O-(6-O-(4-O-malonyl-α-rhamnopyranosyl)-β-glucopyranoside)-5-O-β-glucopyranoside (2), malvidin 3-O-(6-O-α-rhamnopyranosyl-β-glucopyranoside)-5-O-(6-O-malonyl-β-glucopyranoside) (3), malvidin 3-O-(6-O-(4-O-malonyl-α-rhamnopyranosyl)-β-glucopyranoside)-5-O-(6-O-malonyl-β-glucopyranoside) (4), malvidin 3-O-(6-O-(4-O-malonyl-α-rhamnopyranosyl)-β-glucopyranoside) (5) and malvidin 3-O-(6-O-(Z)-p-coumaroyl-β-glucopyranoside)-5-O-β-glucopyranoside (6), in addition to the 3-O-(6-O-α-rhamnopyranosyl-β-glucopyranoside)-5-O-β-glucopyranoside (1) and the 3-O-(6-O-(E)-p-coumaroyl-β-glucopyranoside)-5-O-β-glucopyranoside (7) of malvidin have been isolated from purple leaves of Oxalis triangularis A. St.-Hil. In pigments 2, 4 and 5 a malonyl unit is linked to the rhamnose 4-position, which has not been reported previously for any anthocyanin before. The identifications were mainly based on 2D NMR spectroscopy and electrospray MS.Five novel anthocyanins, the 3-(6-(4-malonylrhamnosyl)glucoside)-5-glucoside (2), the 3-(6-rhamnosylglucoside)-5-(6-malonylglucoside) (3), the 3-(6-(4-malonylrhamnosyl)glucoside)-5-(6-malonylglucoside) (4), the 3-(6-(4-malonylrhamnosyl)glucoside) (5) and the 3-(6-(Z)-pcoumaroylglucoside)-5-glucoside (6) of malvidin have been isolated from methanolic extracts of leaves of Oxalis triangularis.