Advanced Materials Research Vols. 554-556

Abstract: A hydride atomic fluorescence spectrometry method was developed for the determination of trace mercury in Chinese herbal medicines. A digestion system using HNO3-H2O2 under high pressure was applied for the pretreatment of the samples. The operating condition of the instrument were optimized. The effect of the acid in sample solution and carrier liquid, and the effect of reducing agent KBH4 in solution to the determination of mercury were studied. Under the optimum conditions. Five kinds of Chinese herbal medicines in Yun Nan province of China was measured. There was a good linear coefficient between the fluorescent intensity and mercury concentration in the range of 0～10μg•L-1with a correlation coefficient of 0.9998,while the determination limits was 3.7ng•L-1,the relative standard deviation was 2.4%. The content of total mercury in the samples was 5.25～16.32ng•g-1 and a recovery range of 83.6%～109.2% were obtained.

Abstract: The medicinal plant Scutellaria baicalensis Georgi has been used widely in traditional Chinese medicine for anti-inflammation, anticancer, antiviral and antibacterial infections, reducing the total cholesterol level and decreasing blood pressures. Baicalein and baicalin are two major flavonoid of Scutellaria baicalensis Georgi, exhibit various bioactivities. In the present study, the stimulatory activity of baicalin and baicalein derived from Scutellaria baicalensis on insulin secretion in vitro was investigated using HIT-T15 cell, a Syrian hamster transformed β-cell line. The survival rate of cells treated with baicalin or baicalein (0.01-0.5 mg/ml) increased significantly (P < 0.05). In the presence of 5.6 mM glucose, baicalin or baicalein (0.01-0.5 mg/ml) increased glucose-stimulated insulin secretion and cellular ATP levels in HIT-T15 cells. Baicalin and baicalein exhibited significant stimulatory activity in a dose-dependent manner without apparent cytotoxicity at concentrations less than 0.1 mg/ml. The results obtained in this study suggest that baicalin or baicalein increases the insulin secretion of HIT-T15 cells by the enhancement of β-cells activity and cellular ATP levels. Baicalin or baicalein could be candidates for a new class of anti-diabetic drugs.

Abstract: The binding reaction of Zn(II) complex [Zn(C₈H₁₀N)₂Cl₂] with bovine serum albumin(BSA) was studied by fluorescence spectroscopy under the simulative physiological conditions. The intrinsic fluorescence of BSA could be quenched by Zn(II) complex. The quenching mechanism was suggested as static quenching according to the Stern–Volmer equation. The binding constants K_b and the number of binding sites n were calculated. The Zn(II) complex exhibit good binding propensity to bovine serum albumin having relatively high binding constant values. The thermodynamic parameters indicate that the hydrogen bonds and van der Waals forces play a major role in BSA-Zn(II) complex association. The process of binding was spontaneous, in which Gibbs free energy change (Δ_G) was negative.

Abstract: Five triterpenoids were isolated from Gentiana farreri, which was used as traditonal Tibetan medicine in the treatment of some diseases. Their structures were identified as: pseudotaraxasterol (1), lupeol (2), ursolic acid (3), 2α, 3ß-dihydroxylursolic acid (4), 2α,3ß-dihydroxyloleanolic acid (5). All these compounds were isolated from G. farreri for the first time. The cytotoxic activity on the growth of HepG-2 cells of all compounds were investigated in MTT assay, the results showed that compound 3, 4, 5 have high cytotoxic activity, IC50 is 100.88, 13.03, 13.19 (μg/ml), respectively.

Abstract: In this research, a series of novel benzimidazolium compounds were designed, synthesized and evaluated for antibacterial and antifungal activities against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Bacillus proteus, and two fungi, Candida albicans and Aspergillus fumigatus. All of the synthesized compounds exhibited significant activity against the evaluated bacteria. The structures of these novel compounds were measured by 1H NMR, IR and mass spectrum.

Abstract: To find the differences in the internal transcribed spacer(ITS) sequences and provide scientific data for the authentication of Potentilla chinensis and its related species, we extracted the genome DNA from the leaves of 5 common Potetilla species in Jilin Province, amplified the ITS region using ITS universal primers of angiosperm, and sequenced the purified PCR products directly. Polymorphism of ITS sequences was found within P. chinensis and the sequence data suggested that our samples of this species might be related to hybridization. Other 4 species showed intraspecies-stability in ITS sequence. The ITS sequences of these 5 Potentilla species are significantly different. So ITS sequence analysis and other methods derived from it can be used in authentication of Potentilla.

Abstract: Tryptanthrin (TPT), which is an indoloquinazoline alkaloid with multiple biological activities, was studied on its sulfonation in order to increase its water solubility. An 8-substituted tryptanthrin sulfonate (TPTS) was synthesized and structurally characterized by IR, 1H-NMR, ESI-MS, as well as X-ray single crystal diffraction analysis. The interactional mechanism of TPTS with calf thymus DNA (ctDNA) was further studied by UV spectroscopy and DNA viscosity experiment. The addition of ctDNA into the TPTS solution induced moderate hypochromicity on its electronic absorption spectrum, by which an intrinsic binding constant of 1.10×104 M-1 was achieved. While addition of TPTS caused significant increasement on the viscosity of ctDNA solution. The results suggest that TPTS interacts with ctDNA mainly by intercalative binding mode.

Abstract: The Ru(phen)32+ complex forms a regular octahedron and the Ru(phen)₃ unit is a nearly regular trigonal pyramid with ~90° angles. Lengths between Ru and six nitrogen atoms showed slightly different, and rather insensitive to –CF₃ group substituted, as well as the oxidation. There is manifest influence of perfluoro group substitutions on the HOMO and LUMO energies and the substitution of –CF₃ enhances the electron-transport abilities, as well as the complex stability. By substitution of –CF₃ group show increased λ, with addition one –CF₃, a.u 0.02~0.03 ev increase consequently, indicating that the –CF₃ in ligand will hinder hole transport. But, the reorganization energies for these complexes are really values compared with other materials for optoelectronic devices.

Abstract: PI3K, phosphatidylinositol-3-kinase, is a specific lipid kinase family. It is associated with cell proliferation and survival..Class-IA PI3K is heterodimers composed of catalytic subunit (p110) and regulatory subunit (p85). p85α is the most abundant regulatory subunit of PI3K family. PI3K-p85α partial cDNA was amplified by RT-PCR from Inner Mongolia Cashmere Goat (Capra hircus) and sequenced. The molecular characterization of the PI3K-p85α gene was described. The amplified fragment is 1152bp in length, corresponding to a polypeptide of 384 amino acids residues with 45.4 kDa predicted molecular mass. The cDNA nucleotide sequence has 98% identity with regulatory subunit alpha (PIK3R1) of bovine and 93% identity with human. The goat PI3K-p85α patial cDNA is cloned.

Abstract: Microalgae are a biochemically diverse assemblage of microorganisms amenable to fermentation and mass culture.Most of these microalgae species produce unique products like carotenoids，antioxidants，fatty acids，enzymes，polymers，peptides，toxins and sterols.Microalgae might become economic sources of new drugs，other specialty chemicals and functional foods because production can be optimized in controlled culture.This paper introduced the biologically active compounds from microalgae and its health function，studies of microalgae in human nutrition and new trends in microalgae food，researched on microalgal health food，and the development of information was provided.