tannins and delphinidin

In this study, the content, structure, antityrosinase activity, and mechanism of longan bark condensed tannins were evaluated. The findings obtained from mass spectrometry demonstrated that longan bark condensed tannins were mixtures of procyanidins, propelargonidins, prodelphinidins, and their acyl derivatives (galloyl and p-hydroxybenzoate). The enzyme analysis indicated that these mixtures were efficient, reversible, and mixed (competitive is dominant) inhibitor of tyrosinase. What's more, the mixtures showed good inhibitions on proliferation, intracellular enzyme activity and melanogenesis of mouse melanoma cells (B

Topics: Animals; Anthocyanins; Biflavonoids; Catechin; Cell Proliferation; Enzyme Inhibitors; Hydrogen Bonding; Hydrophobic and Hydrophilic Interactions; Mass Spectrometry; Melanins; Melanoma, Experimental; Mice; Models, Molecular; Molecular Docking Simulation; Monophenol Monooxygenase; Oxidoreductases; Parabens; Plant Bark; Proanthocyanidins; Sapindaceae; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Static Electricity; Structure-Activity Relationship; Tannins

Phenolic compounds are present at very high concentrations in the bark of Acacia mangium. These compounds are known to have strong antioxidant activity and thus different beneficial effects on human health. Phenolic compounds in bark of A. mangium were extracted and their antioxidant activities were investigated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging and ferric-reducing antioxidant power (FRAP) assays. A central composite design has been employed to optimize the experimental conditions for a high total phenolic content and antioxidant activity. The desirability function approach has been employed to simultaneously optimize the three responses: total phenols, antiradical activity and FRAP. An extraction time of 90 min, liquid-solid ratio of 5, and temperature of 50 degrees C was predicted for the optimum experimental conditions using the desirability function. A significant linear relationship between antioxidant potency, antiradical activity and the content of phenolic compounds of bark extracts was observed. The structures of condensed tannins isolated from A. mangium were characterized by MALDI-TOF MS analyses. Condensed tannin oligomers from A. mangium were shown to be heterogeneous mixtures consisting of procyanidin and prodelphinidin structural units with polymerization degrees up to 9.

Topics: Acacia; Anthocyanins; Antioxidants; Biflavonoids; Catechin; Humans; Phenols; Plant Bark; Plant Extracts; Proanthocyanidins; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tannins

White clover flowers (Trifolium repens L.) contain an abundance of phenolics, namely cis- and trans-p-coumaric acid 4-O-beta-D-glucopyranoside, the 3-O-beta-D-galactopyranosides of myricetin, quercetin and kaempferol together with two new derivatives namely myricetin 3-O-(6"-acetyl)-beta-D-galactopyranoside and kaempferol 3-O-(6"-acetyl)-beta-D-galactopyranoside. Gallocatechin, epigallocatechin, gallocatechin-(4alpha-8)-epigallocatechin and their corresponding prodelphinidin polymers were also present. The 13C-NMR spectra showed that the polymers consisted of only gallocatechin and epigallocatechin monomeric units with the latter being about twice as abundant in the extenders but only slightly more than that in the terminating units. The average degree of polymerization was estimated by 13C-NMR and ES-MS, which gave a remarkably consistent result of about 5.8 flavanol units.

Topics: Anthocyanins; Benzopyrans; Chromatography, High Pressure Liquid; Fabaceae; Glycosides; Molecular Structure; Phenols; Plant Stems; Plants, Medicinal; Tannins

Four new acylated delphinidin 3,7-glycosides were isolated from the blue-violet flowers of Consolida armeniaca as major anthocyanin pigments. The first pigment was based on delphinidin 3,7-diglucoside and was identified as delphinidin 3-O-[6-O-(malonyl)-beta-D-glucopyranoside]-7-O- [6-O-(4-O-(6-O-(p-hydroxybenzoyl)-beta-D-glucopyranosyl)-p-hydroxybenzoy l)- beta-D-glucopyranoside] by spectral methods. The other three acylated anthocyanins were based on delphinidin 3-glucoside-7-sophoroside. The second pigment was determined to be delphinidin 3-O-[6-O-(malonyl)-beta-D-glucopyranoside]-7-O-[2-O-(beta-D- glucopyranosyl)-6-O-(4-O-(6-O-(p-hydroxybenzoyl)-beta-D-glucopyranosyl)- p- hydroxybenzoyl)-beta-D-glucopyranoside]. The third pigment was elucidated to be delphinidin 3-O-[6-O-(malonyl)-beta-D-glucopyranoside]-7-O-[2-O-(6-O-(p- hydroxybenzoyl)-beta-D-glucopyranosyl)-6-O-(4-O-(6-O-(p-hydroxybenzoyl)- beta-D- glucopyranosyl)-p-hydroxybenzoyl)-beta-D-glucopyranoside], and the fourth as delphinidin 3-O-[6-O-(malonyl)-beta-D-glucopyranoside]-7- O-glucopyranosyl[(2-O-(6-O-(p-hydroxybenzoyl)-beta-D-glucopyranosyl)-6-O - (4-O-(6-O-(p-hydroxybenzoyl)-beta-D-glucopyranosyl)-p-hydroxybenzoyl)-be ta-D- glucopyranoside].

Topics: Acetylation; Anthocyanins; Benzopyrans; Carbohydrate Conformation; Carbohydrate Sequence; Glucosides; Molecular Sequence Data; Molecular Structure; Pigments, Biological; Plant Extracts; Tannins

The purpose of the present study was to investigate the effects of the flavonoid delphinidin chloride (CAS 528-53-0, IdB 1056) on diabetic microangiopathy. Hamsters were injected with alloxan and cheek pouch microcirculation was observed by a fluorescent microscopy technique 90 days from alloxan. The increase in permeability, the number of adhering leukocytes to venular vessel wall and vasodilatory responses to acetylcholine (Ach) and sodium nitroprusside (SNP) were measured. In diabetic group microvascular permeability and the number of sticking leukocytes to the venular endothelium were increased. Vasoconstriction by Ach was observed while the vasodilation by SNP was significantly attenuated in diabetic animals. These results are consistent for a decreased relaxation and suggest also an impairment in the smooth muscle cell function in diabetic arterioles. IdB 1056 exhibited an inhibitory effect on increased microvascular permeability and on leukocytes adhering to the venular vessels. Indeed, the treatment with IdB 1056 in diabetic hamsters pretreated or not with indometacin, a cyclooxygenase inhibitor, restored the relaxant responses to Ach and SNP. In conclusion, the effects of IdB 1056 observed in vivo at the microcirculatory level prevent the injury to endothelial cell function associated with diabetes and/or oxidative stress.

Topics: Acetylcholine; Animals; Anthocyanins; Benzopyrans; Blood Glucose; Blood Pressure; Body Weight; Capillary Permeability; Cell Adhesion; Cricetinae; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Indomethacin; Leukocytes; Male; Mesocricetus; Microcirculation; Microscopy, Fluorescence; Nitroprusside; Tannins