Selenium Distribution Pattern, Antineoplastic and Immunostimulatory Activities of a Novel Organoselenium Compound Eb

Aim To study the distribution pattern, antineoplastic activity and immtmocompetence of a novel organeselenium compotmd Eb and investigate its in vivo antineoplastic potential. Methods Eb was administered to Kunming mice (dosage, 0.1 g·kg^-1·d^-1) intragastrically for 7 successive days. The contents of selenium in heart, liver, spleen, kidneys, lungs, stomach, brain, muscle, and bone were determined by fluommetric method on the eighth day. MTT assay was used to study tumor growth inhibition of Eb in vitro, and lymphocyte transformation, hemolysin formation and phagocytosis assay were used to study its immunocompetence. Results After 7 days' administration of Eb, the tissue contents of selenium in liver, spleen, lungs, kidneys, and bone of mice increased, especially those in liver and spleen increased significantly, compared with controls; but no significant changes of such contents were fotmd in muscle, heart, brain, and stomach. Eb demonstrated inhibitory effects on human Bel-7402, BGC-823, and Calu-3 cancer cell lines in vitro. Eb also showed ability to enhance lymphocyte transformation and serum hemolysin formation in v/tro and increase the phagocytosis of macrophages. Conclusion The validated antitumor and immtmostimulatory activities of Eb suggest a hypothesis that Eb may behave as a biological response modifier when used as an antitumor agent. Eb is worthy of further study in developing a new antineoplastic and immunity enhancing agent in the light of its antitumor activity, immtmocompetenee and specific distribution in liver, lungs, kidneys, bone, and spleen.

Studies on Manganese Peroxidase Immobilized in Gelatin-containing Microemulsion-based Gels

The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the MnP immobilized together with Mn 2+ and H_2O_2 could effectively oxidize syringaldazine in n-heptane. The immobilized MnP still had a high catalytic activity after one-month storage under a freezing condition. The reuse times have a relation to the amount of the immobilized H_2O_2. When the amount of the immobilized H_2O_2 is sufficient, the microemulsion-based gels containing MnP could be used many times.

Two New Xanthone Glycosides from Polygala tenuifolia

Two new xanthone glycosides, polygalaxanthone IV and V were isolated from the roots of Polygala tenuifolia Willd. Their structures were established as 6-O-[a-L-rhamnopyranosyl- (12)-b-D-glucopyranosyl]-1-hydroxy-3, 7-dimethoxyxanthone (polygalaxanthone IV), and 6-O- [a-L-rhamnopyranosyl-(12)-b-D-glucopyranosyl]-1, 3-dihydroxy-7-methoxyxanthone (polyga- laxanthone V), respectively, on the basis of chemical and spectral evidence.

Influence of composition on friction-wear behavior of composite materi-als reinforced by brass fibers

In the study, for the composite materials reinforced by brass fibers, theinfluence of dominant ingredients, such as organic adhesion agent, cast iron debris, brass fiber,and graphite powder, on the friction-wear characteristics was investigated. The friction-wearexperiment was carried out on the block-on-ring tribometer MM 200. The worn surfaces of the frictionpair consisting of the composite materials and grey cast iron HT 200 under dry sliding frictionwere examined using scanning electron microscope (SEM), energy dispersive analysis (EDX) anddifferential thermal analysis-thermogravimetric analysis (DTA-TAG). The experimental results showedthat the friction coefficient and the wear loss of the composite material increase obviously withthe increase of cast iron debris content, but decrease obviously with the increase of graphitepowder content, and increase a little when the mass fraction of brass fiber was over 19 percent, andthe orientation of brass fiber has obvious influence on friction-wear property. When the massfraction of organic adhesion agent was about 10-11 percent, the composite materials have anexcellent friction-wear performance. The friction heat can pyrolyze organic ingredient in wornsurface layer.

Abrasive wear characteristics and mechanisms of Al_2O_3/PA1010 composite coatings

The abrasive wear characteristics of Al_2O_3/PA1010 composite coatings on thesurface of quenched and low-temperature temper steel 45 were tested on the template abrasive weartesting machine and the same uncoated steel 45 was used as a reference material. Experimentalresults showed that the abrasive wear resistance of Al_2O_3/PA1010 composite coatings has a goodlinear relationship with the volume fraction of Al_2O_3 particles in Al_2O_3/PA1010 compositecoatings, and the linear correlative coefficient is 0.979. Under the experimental conditions, thesize of Al_2O_3 particles (40.5-161.0 μm) has little influence on the abrasive wear resistance ofAl_2O_3/PA1010 composite coatings. By treating the surface of Al_2O_3 particles with a suitablebonding agent, the distribution of Al_2O_3 particles in matrix PA1010 is more homogeneous and thebonding state between Al_2O_3 particles and matrix PA1010 is better. Therefore, the Al_2O_3particles in Al_2O_3/PA1010 composite coatings make the Al_2O_3/PA1010 composite coatings havebetter abrasive wear resistance than PA1010 coatings. The wear resistance of Al_2O_3/PA1010composite coatings is about 45% compared with that of steel 45.

Iridoid Glycosides from Buddleja lindeyana

Aim To study the chemical constituents of Buddleja lindeyana. Methods The constituents were separated and purified by different methods of chromatography, and their structures were elucidated by IR, MS and NMR. Results Three iridoid glycosides and two other compounds were isolated from Buddeja lindeyana. Their structures were elucidated to be 6-O-fendoylajugol (1), erythro-6-oxo-4'-(3-methoxyl-4-hydroxyphenylglycol-8')-fendoylaj-ugol (2), threo-6-oxo-4'-(3-methoxyl-4-hydroxyphenylglycol-8')-fendoylajugol (3), tetra-cosanoic acid 2,3-dihydroxypropyl ester (4), and galactitol (5). Conclusion All the compounds have been isolated from this plant for the first time. Compounds 1,2 and 3 have protective effect agains MPP^+-induced apoptosis.

Two New Sequiterpenoids from Helicteres angustifolia

A new sesquiterpenoid lactone, 3,6,9-trimethyl-pyrano[2,3,4-de]chromen-2-one (1) and a novel sesquiterpenoid quinone, 6-[2-(5-acetyl-2,7-dimethyl-8-oxo-bicyclo[4.2.0]octa-1,3,5- trien-7-yl)-2-oxo-ethyl]-3,9-dimethylnaphtho[1,8-bc]pyran-7,8-dione (2) together with a known perezone (3) were isolated from the roots of Helicteres angustifolia. The structures were elucidated as mainly on the basis of 1D and 2D NMR spectroscopic data.

Homoerydictyl-7-O-β-D-glycosidc—A Receptor Antagonist of Platelet-activating Factor （PAF）

Homoeriodictyl-7-O-β-D-glycoside, a flavonoid compound isolated from the Chinese medic inalherb, viscum coloratura inhibited platelet aggregation induced by platelet-activating factor(PAF), but it had no inhibitory activity on adenosine diphosphate-induced platelet aggregation. In the present study, we intended to get an insight into the mechanism of its anti-PAF action. Using [^3H]PAF receptor binding assay we found that the compound exhibited inhibitory activity. The inhibitory rate was 18.5%, 28.4%, 58.7%, 78% and 78%, respestively, at concentrations of 10^-8, 10^-7, 10^-6, 10^-5 and 10^-4 mol.L^-1, There was a visible dose-effect relationship as well as a correlation between different concentrations and their inhibitory rates (r=0.985, P<0.05) when the dose was equal to or less than 1×10^-5 mol.L^-1, and its IC50 was 8.0×10^-7 mol.L^-1. The inhibitory rate didn't increase with increasing concentration of the compound when it went beyond1×10^-5 mol.L^-1 indicating competitive inhibition of binding of [^3H]PAF to PAF receptor reached saturation.

Protective effects of 5,4'-dihydroxy-3',5'- dimethoxy-7-O-β-D -glucopyranosyloxy-flavone on experimental hepatic injury

AIM: To investigate the pharmacological effects of rice flavone (5,4'-dihydroxy-3',5'-dimethoxy-7-O-β-D-glucopyranosyloxy-flavone, RF) separated from panicledifferentiating to flowing rice on rat experimental hepatic injury.METHODS: Models of rat acute hepatic injury induced by carbon tetrachloride (CCl4) administration, rat hepatic fibrosis induced by thioacetamide, injury of primary cultured rat hepatocytes induced by CCl4, respectively,were established. After treated with RF, content of serum alanine transaminase (ALT), aspartate aminotransferase (AST) and albumin (Alb), hyaluronic acid (HA), the activity of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and hydroxyproline (Hyp) were measured and liver tissue was observed pathologically by hematoxylin-eosin (HE) staining. Effects of RF on pathological changes,function index, enzyme of scavenging free radicals and blood rheology were evaluated.RESULTS: In model of rat acute hepatic injury induced by CCl4, RF can significantly decrease the contents of serum ALT, AST, increase the content of Alb, improve the dropsy and fat denaturalization of hepatocytes. In model of rat hepatic fibrosis induced by thioacetamide,RF can inhibit the increase of HA, Hyp and whole blood viscosity, and improve the activities of GSH-Px and SOD,and inauricular microcirculation.CONCLUSION: RF has apparent protective effects on hepatic injury by increasing activity of GSH-Px and SOD,scavenging free radicals produced by CCl4, reducing blood viscosity, and improving microcirculation and blood supply.

Study on the Degradation of Polylactide Microsphere In Vitro

This report concentrated on the rules and mechanism of the degradation of polylactide and the microspheres. The rate of degradation was assessed with five methods: observation of microsphere surface morphology by SEM, determination of the weight loss of the microspheres, determination of the molecular mass of the polymers by GPC, determination of pH and determination of the contents of lactic acid by UV spectrophotometry. The degradation of polylactide microspheres showed two-phase characteristics. At the early stage of the degradation, the high molecular mass polymers were cleaved into lower molecular mass fractions and at the late stage, there was a period of erosion and weight loss of the microspheres. The degradation was much slower for polymers with a higher molecular mass. The polylactide degradation showed good regularity.

Diorgano, Dichloro-tin (IV) Complexes of 4-X-Benzohydroxamic Acid (X=Cl, OCH_3): Synthesis, Characterization, Antitumor Activity in Vitro and the Crystal Structure of trans- [Me_2Sn (L_2) _2]

A series of diorganotin (IV) derivatives of R2SnL2 (R = Me, Et, n-Bu, ph or Cl; L = L1 or L2) and their corresponding mixed-ligand complexes R2Sn (L1)(L2) have been prepared and the structure of trans-Me2Sn (L2) 2 was characterized by FT-IR, 1H, 13C and 119Sn NMR spectroscopies, MS, elemental analysis, melting points and X-ray diffraction. The structure-activity relationships were discussed.

A Monoterpene Glycoside from Ehinacea purpurea

Aim To separate and identify chemical constituents of Ehinacea purpurea. Methods Five compounds were isolated from the plant using chromatography. Their structures were elucidated by spectroscopy. Results Five compounds were isolated and their structures were identified as 2, 6-dimethyl-7-octene-2, 3, 6-triol-2-O-β-D-gtucopyranoside (1), 7, 8-furocoumarin (2), 6-methoxy-7-hydroxycoumarin (3), caffeic acid (4), methyl catfeate (5), and ethyl catfeate(6). Conclusion All these compounds were obtained from the plant for the first time.

Syntheses and Pharmacological Activity of Some 17-[（2＇-Substituted）-4＇-pyrimidyl]androstene Derivatives As Inhibitors of Human 17α-Hydroxylase／C17,20-Layse＊

17-Heterocyclic substituted androstene derivatives have been found to be potent inhibitors for human testicular microsomal 17α-hydroxylase/C17.20-layse, which have potential usage in the treatment of benign prostatic hypertrophy(BPH) and prostatic cancer. In order to further investigate their structure-activity relationships, seven new 17-[(2'-substituted)-4'-pyrimidyl]androstene derivatives were designed and synthesized. The structures of the compounds were confirmed by IR, ^1H NMR, elemental analysis or MS measurements. The results of the pharmacological activity tests showed that'compound 5 is a potent inhibitor for P45017α with IC50 225 nmol.L^-1.

Pollen Morphology of Artemisia L. and Its Systematic Significance

The pollen of 57 species representing 7 sections ofArtemisia was examined by light microscope and scanning microscope for the purpose to elucidate the systematic relationships of the genus. The examination indicates that the pollen grains present high concordance which is characterized by the globular or the approximate shape, 3-lobed circular from polar view while granular or ellipse sphere from tropical plate with tricolporate structure. The exine of pollen has an obvious double structure of inner and outer layers (including the tectum and columnar layers) where the outer is thicker than the inner and the sculpture of exine degenerates into small spinules easily distinguishable from other genera of the Compositae. Based on exine sculpture. the pollen grains ofArtemisia can be divided into two types: Myriantha type and Mongolica type, which possesses 4 subtypes according to the distribution forms of spinule: (1) Sacrorum subtype, (2) Oligocarpa subtype, (3) Lavandulaefolia subtype, (4) Anomale subtype.

Active Oxygen Generation as a Possible Mechanism of Selenium Toxicity

Selenium plays an important role in scavenging active oxygen (AO) species as an essential constituent of glutathione peroxidase. On the other hand, several reports proposed a possible induction of toxic AO by selenium compounds in vitro. However, some of these experiments including ours, were revealed to conclude on the basis of experimental artifacts, and to have problems in the interpretation of data.Methods or principles so far used for the detection of AO species generated by selenium compound were measurement of chemiluminescence from lucigenin or luminol by AO species,the spectrophotometric analysis of reduction of ferricytochrome c or nitroblue tetrazolium (NBT) by superoxide anion (O2-), electron spin resonance (ESR) spectra using dimethylpyrroline oxide (DMPO) as a spin trapping agent, the deoxyribose decomposition by hydroxyl radical (HO), the salicylate hydroxylation by HO, and the strand breakage of DNA by AO. Many of these methods together with their principles seem to have some defects which prevent clear conclusion as stated below. (i) Lucigenin was found to mediate the formation of O2- in the presence of selenite and reduced glutathione (GSH). Therefore, lucigenin is not a suitable reagent. (ii) Luminol may also mediate O2- generation in the presence of HO. (iii) ferricytochrome c can be reduced to ferrocytochrome c in the mixture of selenite and GSH in the absence of oxygen. Moreover, the spectrophotometric method is interfered by turbidity of elemental selenium formed under some conditions in the reaction mixture containing selenite and GSH. (iv) NBT is also reduced by selenium compounds in the absence of O2.(v) ESR signals of AO species were obtained in the reaction mixture containing selenite and GSH, or in the solution of hydrogen selenide in the presence of O2. However, selenide decomposed spin adduct of DMPO with HO' (DMPO-OH). Therefore, the intensity of the signals is not quantitative. (vi) CuZn-SOD is not necessarily a good tool to prov the involvement of O2-, because it enhanced HO generatdri in the reaction mixture containing selenite and GSH.Thus, we would like to emphasize that carefully designed experiments are required to further identify the molecular species of active oxygen induced by selenium compounds