A new anthraquinone and eight constituents from Hedyotis caudatifolia Merr. et Metcalf: isolation, purification and structural identification.

Hedyotis caudatifolia Merr. et Metcalf. (HC), a folk medicine in Yao nationalities areas in China, was used to investigate the chemical constituents. Through silica gel and Sephadex LH-20 column chromatography, nine compounds were isolated and purified. By physical and chemical properties, IR, MS (EI-MS, high resolution EI-MS), 1D NMR ((1)H NMR, (13)C NMR) and 2D NMR (HSQC, (1)H-(1)H COSY, HMBC), their structures were identified as ß-sitosterol (1), stigmasterol (2), scopolin (3), 2-hydroxy-1,7,8-trimethoxyanthracene-9,10-dione (4), oleanolic acid (5), ursolic acid (6), methyl barbinervate (7), ß-daucosterol (8) and p-Hydroxybenzoic acid (9). These compounds were isolated from HC for the first time, and 4 a new anthraquinone whose biological activities are worth to be investigated in future. These compounds may contribute to the HC's pharmacological effects on treating diseases, and may be used as candidates for control index in establishing the quality control standard of HC.

Molecular docking and reaction kinetic studies of chrysin binding to serum albumin.

The binding properties of chrysin with serum albumin (SA) were investigated under physiological conditions by calorimetry, circular dichroism (CD) spectroscopy, and molecular modeling. Based on the thermodynamic data, molar reaction enthalpy, reaction order (n) and the rate constant (k) were calculated. The results of CD spectroscopy showed that chrysin could bind to SA and the conformation of SA did not have any high-ordered structural change. Computational mapping revealed chrysin binding to the subdomain IB in SA. The chrysin-serum albumin complex was stabilized by hydrophobic force and hydrogen bonding and the reaction was a spontaneous process.

Extracts from the roots of Incarvillea younghusbandii on antioxidant effects and life span prolonging in Drosophila melanogaster.

AIM: To investigate antioxidant activities and life span prolonging effects of the extracts from the roots of Incarvillea younghusbandii Sprague, and to study the correlations between these activities and the polar intensity of the extracts. METHOD: Five extracts (IYS1, IYS2, IYS3, IYS4 and YS5) with different polar intensity were prepared. Antioxidant activities in vitro were determined by LPO inhibitory and free radicals scavenging experiments. Life span prolonging effects in vivo were evaluated by feeding Drosophila melanogaster. RESULT: Total phenolic content in extracts were solvent-dependent and decreased in the order of IYS4 > IYS1 >> IYS3 > IYS5 > IYS2. Organic extracts (IYS1 and IYS4) showed excellent LPO inhibitory activity, O(2)(· -) and ·OH scavenging activity compared to ascorbic acid (or benzoic acid, or BHT), while aqueous extracts (IYS2, IYS3 and IYS5) did not. The antioxidant activities (in vitro) were solvent dependent and decreased in the order of IYS4 > IYS1 > IYS3 > IYS5 ≥ IYS2. Drosophila melanogaster was fed with organic extracts (IYS1 or IYS4) at 5.0 mg mL(-1). The mean life span were increased by 24.4% (IYS1) or 23.0% (IYS4) in female and 15.3% (IYS1) or 16.9% (IYS4) in male; the maximum life span were increased by 8.4% (IYS1) or 11.2% (IYS4) in female and 9.7% (IYS1) or 15.8% (IYS4) in male, and the survival curves were significantly shifted to the right after fifteen days in both sexes survival period. Feeding aqueous extracts (IYS2, IYS3 or IYS5) at 5.0 mg·mL(-1), the significant life span prolonging effects were not achieved. The life span prolonging effects of the extracts were solvent-dependent and decreased in the order of IYS4 ≥ IYS1 >> IYS3 > IYS2 > IYS5. CONCLUSION: Extracts from the roots of Incarvillea younghusbandii Sprague showed excellent antioxidant activities and significant life span prolonging effects in Drosophila melanogaster. Positive correlations existed between the antioxidant activities and total phenolic content. Life span prolonging effect was positively correlated with the total phenolic content or antioxidant activities. The extracts possess better life span prolonging effect in females than in males.

Isolation, purification and structure identification of two phenolic glycosides from the roots of Incarvillea younghusbandii Sprague and their antioxidant activities.

Using a bioassay-guided fractionation technique, two compounds were isolated from the roots of Incarvillea younghusbandii Sprague through silica gel, reverse-phase C18 column chromatography and reverse-phase HPLC. Their structures were identified as acteoside (1) and isoacteoside (2) by ESI-MS, GC-MS, 1D- and 2D-NMR. 1 and 2 showed *OH scavenging capacity similar with benzoic acid, higher O2*- (or *OH) scavenging capacity than ascorbic acid, far higher hepatic LPO inhibitory activities than 2, 6-di-tert-butyl-4-methylphenol (BHT) or ascorbic acid, and more powerful effect on protecting erythrocytes from oxidative damage than ascorbic acid. The *OH scavenging capacity was positively proportional to the concentrations of 1 and 2 ranging from 0.015 6 to 0.500 0 mg x mL(-1). The hepatic LPO inhibitory activities increased with the increasing concentrations of 1 and 2 from 0.001 9 to 0.250 0 mg x mL(-1), but decreased slightly with the increasing concentration from 0.250 0 to 1.0000 mg x L(-1).