hyperoside and myricetin

Abelmoschus manihot (L.) Medic., a folk herbal medicine in China, is a flowering plant belonging\ to Abelmoschus L. genus and Malvaceae family, which has been reported with an antidepressant activity. The\ study was designed to isolate flavonoids from Abelmoschus manihot corolla and explore the action mechanism\ of antidepressant activities. The flavonoids were isolated and purified by D101 macroporous resin column,\ polyamide column and Sephadex LH-20 sequentially and identified as myricetin-3-O-β-D-glucoside (1),\ gossypetin-8-O-β-D-glucuronide (2, G-8-G), gossypetin-3'-O-β-D-glucoside (3), quercetin-3'-glucoside (4, Q-3-G),\ isoquercitrin (5, IQT), hyperoside (6, HY), myricetin (7), quercetin (8, QT). Compounds 2, 4, 5, 6 and 8\ (15, 30 and 60 mg·kg−1) were orally administered to mice and the reaction was observed in tail suspension\ test (TST) and forced swimming test (FST). Western blot analysis was used in determination of the protein\ expressions of brain-derived neurotrophic factor (BDNF), tyrosine receptor kinase B (TrkB) and phosphorylation\ eukaryotic elongation factor 2 (p-eEF2). The results revealed that only Q-3-G and G-8-G (15, 30, 60 mg ·kg−1)\ significantly reduced the immobility time in FST and TST. Furthermore, Q-3-G and G-8-G remarkably increased\ the expression of BDNF and TrkB, and decreased the expression of p-eEF2. These results suggest that\ Q-3-G and G-8-G had an obvious antidepressant activity via up-regulation of BDNF expression. The\ new observation will provide a new direction in the development of antidepressant in the treatment of major depressive\ disorder (MDD).

Topics: Abelmoschus; Animals; Antidepressive Agents; Brain-Derived Neurotrophic Factor; China; Depressive Disorder, Major; Drugs, Chinese Herbal; Ethanol; Flavonoids; Hindlimb Suspension; Hippocampus; Mice; Plant Extracts; Quercetin; Swimming; Up-Regulation

We investigated the chemical constituents of the leaves of Psidum littorale, which include 16 flavonoids, including seven flavonols, six flavonoid glycosides and three flavonones. The compounds were isolated by silica gel column chromatography. Their structures were elucidated on the basis of spectral analysis and by comparison with published data. Seven flavonols were kaempferol (1), isorhamnetin (2), myricetin- 3,7,3’-trimethyl ether(3), laricitrin (4), quercetin (5), myricetin (6) and quercein-3,4’-dimethyl ether (7), six flavonoid glycosides were guaijaverin (8), hyperoside (9), 5,4’-dyhydroxy-3,7,5’-methoxyflavone-3’-O-β-D- glucoside (10), laricitrin-3-O-xyloside (11), myricetin-3-O-α-L-rhamnopyranoside (12) and myricetin-3-O-β-D- xyloside (13). Three flavonones were 4’-O-methyldihydroquercetin (14), dihydroapigenin (15) and ampelopsin 4’-O-β-D-glucopyranoside (16). Compound 10 is a new chemical, compounds 2-4, 7, 10-16 were first isolated from this plant. (1)H NMR and (13)C NMR data of compound 11 were not reported in literature.

Topics: Flavonoids; Flavonols; Glycosides; Kaempferols; Plant Leaves; Psidium; Quercetin

To Set up a method for determining the contents of the five flavonoids simultaneously in the HuangKui capsule and analyze their specific chromatograms.. HPLC method was used. The analytical column was Thermo scientific Hypersil GOLD (250 mm x 4.6 mm, 5 microm). The mobile phase was composed of acetonitrile (A) and 0.2% orthophosphoric acid (B) with gradient elution. The flow rate was 0.8 mL/min and detection wavelength was 360 nm. The column temperature was maintained at 30 degrees C.. Contents of the five flavonoids (Rutin, Hyperoside, Isoquercitrin, Myricetin, Quercitrin) had good resolution with the correlation coefficients exceed 0.9999 and the average percent recovery lied in 98.46% to 100.33%. The chromatograms of the HuangKui capsule shared 15 common peaks in which 5 of them were recognized by the reference standard. Chromatograms of 10 lots of HuangKui capsule were analyzed with the similarities over 0.95.. The proposed method of contents determination and chromatogram analysis has strong characteristic and specificity. This method is fast, easy and reliable, and can be applied for quality control of the preparation.

Topics: Abelmoschus; Capsules; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Flavonoids; Quality Control; Quercetin; Reproducibility of Results; Rutin

Severe acute respiratory syndrome (SARS) is an infectious disease with a strong potential for transmission upon close personal contact and is caused by the SARS-coronavirus (CoV). However, there are no natural or synthetic compounds currently available that can inhibit SARS-CoV. We examined the inhibitory effects of 64 purified natural compounds against the activity of SARS helicase, nsP13, and the hepatitis C virus (HCV) helicase, NS3h, by conducting fluorescence resonance energy transfer (FRET)-based double-strand (ds) DNA unwinding assay or by using a colorimetry-based ATP hydrolysis assay. While none of the compounds, examined in our study inhibited the DNA unwinding activity or ATPase activity of human HCV helicase protein, we found that myricetin and scutellarein potently inhibit the SARS-CoV helicase protein in vitro by affecting the ATPase activity, but not the unwinding activity, nsP13. In addition, we observed that myricetin and scutellarein did not exhibit cytotoxicity against normal breast epithelial MCF10A cells. Our study demonstrates for the first time that selected naturally-occurring flavonoids, including myricetin and scultellarein might serve as SARS-CoV chemical inhibitors.

Topics: Adenosine Triphosphate; Antiviral Agents; Apigenin; Breast; Cell Line; Cell Proliferation; Colorimetry; DNA; DNA Helicases; Epithelial Cells; Female; Flavonoids; Fluorescence Resonance Energy Transfer; Hepacivirus; Humans; Hydrolysis; Inhibitory Concentration 50; Kinetics; Methyltransferases; RNA Helicases; Severe acute respiratory syndrome-related coronavirus; Species Specificity; Viral Nonstructural Proteins; Viral Proteins

To explore the mechanism of the absorption of flavonoids from Abelmoschus manihot flowers, in situ intestinal recirculation was performed to study the effect of the absorption at different concentrations and different intestinal regions. To evaluate the conditions of the absorption of six flavonoids from Abelmoschus manihot flowers, the concentrations of Abelmoschus manihot in the perfusion solution were determined by HPLC at predesigned time. And we have investigated the inhibitory effect of six flavonoids from Abelmoschus manihot flowers on P-glycoprotein (P-gp) drug efflux pump. The results demonstrated that the absorption rates of flavonoids from Abelmoschus manihot flowers are not significantly different (P > 0.05) at various drug concentrations, the absorption of flavonoids from Abelmoschus manihot flowers is a first-order process with the passive diffusion mechanism. The absorption rates of each of flavonoids are significantly different. The absorption rate of flavonoid glycoside was lower than that of aglycone; the flavonoids from Abelmoschus manihot flowers could be absorbed in all of the intestinal segments. The best parts of intestine to absorb hyperoside and myricetin are jejunum and duodenum, separately. Verapamil could enhance the absorption of isoquercitrin, hyperoside, myricetin and quercetin-3'-O-glucoside by inhibiting P-glycoprotein (P-gp) drug efflux pump.

Topics: Abelmoschus; Animals; ATP Binding Cassette Transporter, Subfamily B; Flavonoids; Flowers; Glucosides; Intestinal Absorption; Male; Perfusion; Plant Extracts; Plants, Medicinal; Quercetin; Rats; Rats, Sprague-Dawley; Verapamil

A high-performance liquid chromatography method is developed for the simultaneous quantification of seven flavonols, namely quercetin-3-O-robinobioside, hyperin, isoquercetin, hibifolin, myricetin, quercetin-3'-O-glucoside, and quercetin, in the flower of Abelmoschus manihot. These seven flavonols are selected as chemical markers because they are the major pharmacologically active constituents in the flower. The method involves the use of a Thermo ODS-2HYEPRSIL reversed-phase column (5 microm, 250 x 4.6 mm) at 25 degrees C with a mixture of acetonitrile and aqueous H(3)PO(4) as the mobile phase and detection at 370 nm. The recovery of the method is 94.31-107.08% with an RSD < or = 3.14% and the linearity (r(2) > 0.9996) is obtained for all the flavonoids. The current assay method can be readily utilized for the determination of the flavonols present in the flower and is considered to be suitable for the quality control of A. manihot samples. The comparison of flowers collected from nine locations shows that flavonoid glucoside is more stable than aglycon in the flower. This is the first study that analyzes the stability of flavonoids in the flower of A. manihot. This research also provides important evidence that the flower is a potentially abundant resource for obtaining hibifolin.

Topics: Abelmoschus; Chromatography, High Pressure Liquid; Drug Stability; Flavonoids; Flavonols; Flowers; Indicators and Reagents; Quercetin; Reproducibility of Results