Zhao Qing

Determination of Antidiabetic Polysaccharides of Ocimum basilicum Seeds Indigenous to Xinjiang of China by High-Performance Thin-Layer Chromatography-UV/Vis-Mass Spectrometry

The seeds of Ocimum basilicum have traditionally been used for the prevention and treatment of a number of diseases in Xinjiang of China. In this study, six polysaccharide extracts were isolated from the seeds of O. basilicum by sequential extraction and purified. After methanolysis, the monosaccharide compositions of the six polysaccharide extracts were analyzed by high-performance thinlayer chromatography (HPTLC) on HPTLC plates silica gel 60 with a mixture of isopropyl acetate-ethyl acetate-methanol-water (5:4:1:0.1, v/v). After derivatization with the aniline diphenylamine o-phosphoric acid reagent, densitometric quantitation was performed by absorbance measurement at 370 or 630 nm. The results revealed that the polysaccharides in O. basilicum seeds consisted primarily of fructose (hRF 80), glucuronic acid (hRF 58), galacturonic acid (hRF 51), rhamnose (hRF 40), xylose (hRF 25), arabinose (hRF 18), and galactose (hRF 9). Xylose, glucuronic acid, and fructose were the three major components found and account for 45, 31, and 21%, respectively. All extracts contained uronic acids, ranged 3 to 24%. An unknown monomeric unit above glucuronic acid was characterized by mass spectrometry (MS) to be a hexuronic acid, and HPTLC-MS proved to be a well suited method for characterization of polysaccharide-based biopolymers and assignment of its monomers. The polysaccharide extracts (aqueous cold, aqueous hot, acidic, and alkaline) showed inhibitor activities of protein tyrosine phosphatase 1B in vitro with half maximal inhibitory concentration (IC50) values of 8.2, 2.2, 70.9, and 0.8 µg mL−1, respectively. For the first time, a molecular basis was provided to explain the hypoglycemic effect of the seeds of O. basilicum that has been used as antidiabetic adjuvant in traditional Chinese medicine.

Preparation and Electrochemical Properties of Graphene-modified TiO2 (Anatase) Nanotubes Composite for Lithium-ion Batteries

TiO2 nanotubes decorated with graphene hybrid material was prepared via a green route, namely, both synthesis of nano tubular TiO2 and reduction of GO were simultaneously carried out in alkali solution under solvothermal conditions. The as-prepared nanocomposite was used for investigation of Li-ion insertion properties. TEM analysis highlights the excellent crystallinity of the anatase TiO2 nanotubes, 5∼7 nm in external diameter and several hundred nanometers in length, loaded on graphene sheets. The composite exhibits a high capacity and about 0.8 Li per TiO2 can be delivered in the first discharge and charge at a current density of 0.1 C, larger than the values for the TNs (0.6 Li per TiO2). The electrochemical performance of the composite is superior to that of the bare TNs anode, indicating a positive synergistic effect of nanotubular TiO2 and graphene.TiO2 nanotubes decorated with graphene hybrid material was prepared via a green route, namely, both synthesis of nano tubular TiO2 and reduction of GO were simultaneously carried out in alkali solution under solvothermal conditions. The as-prepared nanocomposite was used for investigation of Li-ion insertion properties. TEM analysis highlights the excellent crystallinity of the anatase TiO2 nanotubes, 5 approximate to 7 nm in external diameter and several hundred nanometers in length, loaded on graphene sheets. The composite exhibits a high capacity and about 0.8 Li per TiO2 can be delivered in the first discharge and charge at a current density of 0.1 C, larger than the values for the TNs (0.6 Li per TiO2). The electrochemical performance of the composite is superior to that of the bare TNs anode, indicating a positive synergistic effect of nanotubular TiO2 and graphene.

Correlation analysis of spectral reflectance in determining preliminary algorithms for water quality monitoring in Taihu Lake, China

This paper presents an empirical relationship that maybe used to potentially estimate suspended sediments, chlorophyll concentrations and yellow substances from remote sensing reflectance measurements in highly turbid water body-Taihu Lake, China. Based on the characterization of the reflectance spectra of chlorophyll and suspended sediments, the correlation between constituents concentration with spectral reflectance and reflectance ratio of arbitrary wavelength are analyzed and discussed, which provides a substantial basis for wavelength selection criterion for the inversion of water constituents concentrations in Taihu Lake. A empirical approach of relating reflectance ratio to in situ measurements through regression analysis was used. The regression results show that the ratio between the reflectance of the wavelength with higher correlation is superior to the ratio between the reflectance with lower correlation. Based on the comparison of the correlation analysis of the water constituents, the generalized band ratio of high correlation with water constituents were proposed. These results implies that the reflectance spectral features and the correlation profiles play a crucial role in providing appropriate criterion for band selection on water quality monitoring in Taihu Lake, China, which is especially constructive for remote sensing purposes and should be applied in other turbid waters

Isolation and Characterization of a Polysaccharide from Ocimum basilicum Seeds

Seeds of Ocimum basilicum L. are used in traditional medicine for stomach ulcers, dyspepsia, diarrhea, pharyngitis, and kidney inflammation [1]. Basil seeds are often included in drinks (sherbet) and frozen desserts (faloodeh) for esthetics and as a source of dietary fiber in Iran and many regions of Asia [2, 3]. The external pericarp swells upon wetting with water and forms a gel-like coating [4] because of the presence of a polysaccharide layer. We communicated previously that polysaccharides isolated from O. basilicum seeds consisted of fructose, glucuronic acid, galacturonic acid, rhamnose, xylose, arabinose, and galactose. The principal constituents were xylose, glucuronic acid, and arabinose [5]. In continuation of research in this area, we present results on the isolation and purification of acidic watersoluble polysaccharides from O. basilicum fruit by column chromatography over DEAE-Sepharose CL-6B and Sephadex G-100 and on their structures according to IR and NMR spectroscopy. Pure acidic polysaccharides were obtained using the previously obtained acidic water-soluble polysaccharide (WSPSH-A) [5]. WSPS-H-A (200 mg) was dissolved in distilled H2O (6 mL) and centrifuged for 5 min at 10,000 rpm and 4°C. The supernatant liquid was transferred to a Servacel DEAE-23SN ion-exchange column (25 mm 25 cm) and eluted with H2O and NaCl solutions (concentrations 0.2, 0.5, and 1.0 M). The polysaccharide yield was monitored using the phenol–H2SO4 method. The polysaccharide content in the fraction eluted by H2O was 12.6 mg (fraction 1, 6.3%); by NaCl (0.2 M), 170 mg (fraction 2, 80%); by NaCl (0.5 M), 19.5 mg (fraction 3, 9.7%); and by NaCl (1.0 M), 5.1 mg (fraction 4, 2.5%). A total of 98.5% of the polysaccharide fraction was recovered. Fraction 2 (50 mg) was separated by column chromatography over Sephadex G-100 on an HP Polysaccharide Purifier 10 instrument equipped with conductivity, UV, and differential detectors to afford homogeneous fraction 2-1 (13.1 mg yield). The IR spectrum of fraction 2-1 had absorption bands at 3411 cm 1 (OH), 1642 (carboxyl), 1200–1000 (C–Ñ and C–O stretching), 800 (pyranose ring), and 873 ( -glycoside bond) [6]. The structure of fraction 2-1 was studied using PMR and 13C NMR spectroscopy and 2D COSY, HSQC, and HMBC methods. PMR spectra in the region of anomeric protons exhibited four resonances at 5.30 ppm (strongest), 4.86 (minor), 4.64, and 4.48. Other proton resonances were located in the range 3.2–4.4 ppm. A strong singlet at 3.48 ppm was characteristic of an OCH3 group. The strong-field spectral region contained a doublet at 1.26 ppm (J = 4.2 Hz) that was characteristic of a rhamnopyranose (Rhap) methyl. The 13C NMR spectrum showed in the range 100–105 ppm four anomeric resonances at 100.44, 102.79, 104.23, and 104.69 ppm. The first strong resonance belonged to C-1 of -glucuronic acid ( -GlcpA). The other anomeric resonances were assigned to -rhamnopyranose ( -Rhap, weak), -xylopyranose ( -Xylp), and -arabinopyranose ( -Arap). A resonance at 179.97 ppm that gave a cross-peak with the glucuronic acid C-5 proton in the HMBC spectrum indicated that uronic acid was present. A resonance at 62.69 ppm was indicative of uronic-acid methyl-ester OCH3 groups.