Fig 1 - uploaded by Trajce Stafilov
Content may be subject to copyright.
Source publication
Context in source publication
Context 1
... chromone derivatives (flavones, flavonols, flavanones, and flavanonols); 2) chromane derivatives (catechines and antocyanidines); and 3) flavonoids with open propane chain (chalcones) and with a furane ring (aurones). From all of these, flavones, flavonols, and flavanones are the most abundant in the plant kingdom and their skeleton is given in Fig. 1. Substitution in the positions 3, 5, 6, 7, 8, 2', 3', 4', 5', and 6' gives all the compounds from these groups, with hydroxylation, methoxylation, and glycosylation being the most common substitution. Thousands of various flavonoids with various substitution patterns are recognized today as free flavones, flavonols, and flavanones, ...
Similar publications
THE TOTAL PHENOLIC, TOTAL FLAVONOID, AND BROWN
PIGMENT IN HONEY BEFORE AND AFTER HEATING
Citations
... The OD540 was taken against blank (dH2O) with all other reagents (Stefova et al., 2003). ...
Acute hepatitis D (delta) is a chronic liver disease caused with co-infection of hepatitis D virus (HDV) and hepatitis B virus (HBV). In this study, blood serum samples are screened for HBV and HDV infections. The 4 confirmed out of 14 patients with real-time PCR for HDV infected were subjected for further comparative clinical analysis. Among the patients, the hemoglobin (17.18±0.149g/dL) and HCT (50.90±0.235%) levels increased significantly than standard reference values. Similarly, proline and flavonoids also observed higher, while alanine aminotransferase (ALT) and antioxidants decreased (p<0.05) in the patients than normal reference values for the healthy person. These facts could be developed due to HDV stress on the body. The HDV patients showed inversely proportional relations in the levels of hemoglobin and platelets. These differential parameters could be improved with the good nutrients or supplements, which may be helpful for the survival of these patients. This present study could be helpful proper maintenance of HDV patients under HDV treatment.
... In this study, two matching Waters XBrigde C18 columns (10 cm  4.6 mm i.d. and 10 cm  19 mm i.d., 5 mm particle size each) were used. Octadecyl silica is a clear choice, as a vast majority of polyphenol separations has been performed using this column chemistry (Stalikas, 2007;Stefova et al., 2003). The selection of column length of 100 mm allowed to shorten the analysis time. ...
... In flavonoid separations, binary mobile phases consisting of water with acetic or formic acid and methanol or acetonitrile as organic modifiers are most commonly applied. While in analytical experiments gradient elution is generally performed, allowing for separation of a wide range of compounds in a reasonable time, in preparative applications where separation is limited to only a couple of compounds, isocratic mode is preferable, as it eliminates the need of column equilibration and, thus, greatly reduces the costs of the analysis (Marston and Hostettmann, 2006;Stalikas, 2007;Stefova et al., 2003). In the first stage of development of the present method, a series of binary phases in the isocratic elution mode were tested, specifically, 0.5% acetic acid with methanol in concentrations 10-60% (v/v) and with acetonitrile in concentrations 10-50% (v/v). ...
A fast and efficient preparative HPLC-PDA method was developed for the separation and isolation of four rare isomeric kaempferol diglycosides from leaves of Prunus spinosa L. The separation procedure of the enriched diglycoside fraction of the 70% (v/v) aqueous methanolic leaf extract was first optimised on analytical XBridge C18 column (100 mm × 4.6 mm i.d., 5 μm) and central composite design combined with response surface methodology was utilized to establish the optimal separation conditions. The developed method was directly transferred to preparative XBridge Prep C18 column (100 mm × 19 mm i.d., 5 μm) and the final separation was accomplished by isocratic elution with 0.5% acetic acid-methanol-tetrahydrofuran (75.2:16.6:8.2, v/v/v) as the mobile phase, at a flow rate of 13.6 mL/min, in less than 12 min for a single run. Under these conditions, four flavonoid diglycosides: kaempferol 3-O-α-l-arabinofuranoside-7-O-α-l-rhamnopyranoside, kaempferol 3,7-di-O-α-l-rhamnopyranoside (kaempferitrin), and reported for the first time for P. spinosa kaempferol 3-O-β-d-xylopyranoside-7-O-α-l-rhamnopyranoside (lepidoside) and kaempferol 3-O-α-l-arabinopyranoside-7-O-α-l-rhamnopyranoside, were isolated in high separation yield (84.8–94.5%) and purity (92.45–99.79%). Their structures were confirmed by extensive 1D and 2D NMR studies. Additionally, the UHPLC-PDA-ESI–MS³ qualitative profiling led to the identification of twenty-one phenolic compounds and confirmed that the isolates were the major components of the leaf material.
... The preferred solvent system to separate flavonoids on reversed-phase stationary phases from the extract mixture is acetonitrile-water or methanol-water. Sometimes formic acid, acetic acid, phosphoric acid or ammonium dihydrogen phosphate was added to enable improved separation and prevention on peak tailing with respect to the phenolic character of the flavonoids [36,37]. ...
Gingko flavonoids (GFLAs) were isolated from extract Egb761 and radiolabeled with 131I. Quality control and lipophilicity studies for 131I-GFLAs were performed. Cellular incorporation ratios for 131I-GFLAs were investigated. The radiolabeling yield of GFLAs with 131I was 90.69 % ± 3.90 and log P value of 131I-GFLAs was 0.99 ± 0.03 (n = 3). Incorporation of 131I-GFLAs on PC3 and MCF7 cells was satisfactory, whereas higher uptake ratios were observed on PC3 cells. A promising agent for cancer diagnosis is presented.
