SYNTHESIS OF 6-AMINO, 6-METHOXY AND 6-ETHOXY PURINENUCLEOSIDE DERIVATIVES

A convenient route for the conversion of inosine to the corresponding 6-amino, 6-methoxy and 6-ethoxy derivatives is reported. This conversion can be achieved by ammoniation or etherification of the 6-pyridinium intermediate(3) which can be readily produced under mild reaction conditions. The chemistry and characterization of these compounds are presented, A plausible mechanism of the reaction is proposed.

A Density Functional Theory Study of Methoxy and Atomic Hydrogen Chemisorption on Au(100) Surface

The adsorption of CH3O and H on the (100) facet of gold was studied using self-consistent periodic density functional theory (DFT-GGA) calculations. The best binding site, energy, and structural parameter, as well as the local density of states, of each species were determined. CH3O is predicted to strongly adsorb on the bridge and hollow sites, with the bridge site as preferred one, with one of the hydrogen atoms pointing toward a fourfold vacancy (bridge-H hollow). The top site was found to be unstable, the CH3O radical moving to the bridge –H top site during geometry optimization. Adsorption of H is unstable on the hollow site, the atom moving to the bridge site during geometry optimization. The 4-layer slab is predicted to be endothermic with respect to gaseous H2 and a clean Au surface.

Effects of acut and chronic doses of methoxy acetic acid on hamster sperm fertilising ability

Aim: To evaluate the effects of acute and chronic doses of methoxy acetic acid (MAA) on in vitro fertilisation byhamster sperm and to correlate the data with the testicular damage. Methods: Adult male hamsters were gavagedwith 3 single doses (0, 80, 160 and 650 mg/kg) and 3 chronic doses (0, 8, 32 and 64 mg/kg daily for 5 weeks) ofMAA in distilled water. After treatment hamsters were killed at weekly intervals and spermatozoa recovered from thedistal cauda epididymides were used to assess the fertilising capacity in vitro. The testes were processed for histologicalexamination. Results; Acute doses showed a significant reduction in sperm fertilising ability from week 3 and 4 af-ter treatment and with the chronic doses, the effects were more extensive and persistent. The results were in correpon-dence with the testicular damages observed. Conclusion: It is evident that both acute and chronic doses of MAAcan impair the sperm function by damaging one or more cell populations in the testis.(Asian J Androl 2001 Sep; 3: 209- 216)

Why is metallic Pt the best catalyst for methoxy decomposition?

The decomposition of methoxy on Cu（111）, Ag（111）, Au（111）, Ni（111）, Pt（111）, Pd（111）, and Rh（111） has been studied in detail by the density functional theory calculations. The calculated activation barriers were successfully correlated with the coupling matrix element V 2 ad and the d-band center （ε d ） for the group IB metals and group VIII metals, respectively. By comparison of the activation energy barriers of the methoxy decomposition on different metals, it was found that Pt is the best catalyst for methoxy decomposition. The possible reason why the metallic Pt is the best catalyst has been analyzed from both the energetic data and the electronic structure information, that is, methoxy decomposition on Pt（111） has the largest exothermic behavior due to the closest p-band center of the CH 3 O among all metals after the adsorption.

The donor-dependent methoxy effects on the performance of hole-transporting materials for perovskite solar cells

In this work, a comprehensive study on the deliberate molecular design and modifications of electron donors is carried out to elucidate correlations between the methoxy effects and donor configuration of hole-transporting materials(HTMs). Our initial findings demonstrate the donor-dependent methoxy effects. Photovoltaic performance of the HTM with twisted donor highly depends on the methoxy substituent. In contrast, efficiency’s reliance on methoxy is insignificant for the HTM with planar donor. The HTM(M123) featuring the methoxy–substituted carbazole shows a decent power conversion efficiency of 19.33% due to synergistic effects from both planar structure and methoxy. This work gives a guideline to access HTMs reaching both high-performance and good stability.

CATIONIC CONDUCTION IN BLEND COMPLEX OF LITHIUM METHOXY OLIGO (OXYETHYLENE) SULFATE AND COMBLIKE POLYETHER

Two kinds of lithium methoxy oligo(oxyethylene) sulfate LiSAEO_8 and LiSAEO_(12) were synthesized. The blend complexes of the salts with P(MEO_(16)—AM) show high cationic conductivity, the transference numbers of lithium ion(t_+)in [P(MEO_(16)—AM)/LiSAEO_8] and [-P(MEO_(16)—AM)/LiSAEO_(12)] are 0.93 and 0.98 at 50℃, and their ambient conductivities are 1.4×10^(-5)/cm and 7.7×10^(-6)S/cm respectively.

Construction and Characterization of Gal-Chitosan Graft Methoxy Poly(Ethylene Glycol)(Gal-CS-mPEG) Nanoparticles as Efficient Gene Carrier

In the present study, galactosylated chitosan(Gal-CS) was conjugated with methoxy poly(ethylene glycol)(m PEG) as a hydrophilic group. The structure of Gal-CS-m PEG polymer was characterized and the nanoparticles(NPs) were prepared using ironic gelation method. The study was designed to investigate the characteristics and functions of Gal-CS-m PEG NPs. The morphology of Gal-CS-m PEG NPs was observed by SEM and it was a compact and spherical shape. The size of the NPs was approximately 200 nm in diameter under the ideal process parameters. The interaction between Gal-CS-m PEG NPs and p DNA, and the protection of p DNA against DNase I and serum degradation by Gal-CS-m PEG NPs were evaluated. Agarose gel electrophoresis results showed that Gal-CS-m PEG NPs had strong interaction with p DNA at the weight ratio of 12:1, 4:1 and 2:1 and could protect p DNA from DNase I and serum degradation. Gal-CS-m PEG NPs exhibited high loading efficiency and sustainable in vitro release. The blood compatibility studies demonstrated that Gal-CS-m PEG NPs had superior compatibility with erythrocytes in terms of aggregation degree and hemolysis level. Gal-CS-m PEG NPs showed no cytotoxicity on L929 cells, which is a normal mouse connective tissue fibroblast, but showed inhibitory effects on the proliferation of Bel-7402 cells, which is a liver cancer cell line. In conclusion, Gal-CS-m PEG NP is a bio-safe and efficient gene carrier with potential application in gene delivery.

Comparison of Usage and Effectiveness between Methoxy Polyethylene Glycol Epoetin Beta and Darbepoetin Alfa with Hemodialysis Patients

Methoxy polyethylene glycol epoetin beta which has a long half-life is developed to provide stable control of hemoglobin levels at extended administration intervals compared to darbepoetin alfa. The purpose of this study was to compare the patterns of use, efficiency of therapy and cost with undergoing hemodialysis patients. Electronic medical record system was used to examine administration frequency, hemoglobin response rate, achievement of target hemoglobin, drug costs. Administration frequency was once in 4 weeks with methoxy polyethylene glycol epoetin beta group and 3 times in 4 weeks with darbepoetin alfa group. Hemoglobin response rate was 61.5% in methoxy polyethylene glycol epoetin beta at the time of 16 weeks. It was not significantly different from 66.7% in darbepoetin alfa （P = 1.000）. The drug cost for methoxy polyethylene glycol epoetin beta group was little higher than darbepoetin alfa group. However, there was no statistically significant difference （P = 0.164）. Use of methoxy polyethylene glycol epoetin beta is as effective and safe as darbepoetin alfa managing renal anemia in hemodialysis patients. Methoxy polyethylene glycol epoetin beta＇s extended administration interval improve patient＇s compliance and enable effective anemia treatment.

PREPARATION OF 3~H-LABELLED 3-(β-PHENYLETHYL)-9β-METHOXY-9α-(m-PROPIONOXYPHENYL)-3-AZABICYCLO [3.3.1] NONANE AND SOME CHARACTERIZATIONS OF ITS BINDING WITH OPIATE RECEPTOR FROM RAT BRAIN

We have reported that 3-(β-phenylethyl)-9β-methoxy-9α-(m-propionoxyphenyl)-3-azabicyclo [3.3.1] nonane (coded name; P-7548) was a new potent analgesic. Its potency was 2000 times that of morphine (mice, Lp., hot plate). Pharmacological tests further proved that P-7548 characterized its high potency, rapid onset and long

Preparation and Characterization of Polymeric Micelles from Poly (D, L-lactide) and Methoxypolyethylene Glycol Block Copolymers as Potential Drug Carriers

Amphiphilic diblock copolymers composed of methoxy polyethylene glycol （MePEG） and poly（D,L-lactide） （PDLLA） were prepared for the preparation of polymeric micelles, The use of MePEG-PDLLA as drug carriers has been reported in the open literature, but there are only few data on the application of a series of MePEG-PDLLA copolymers with different lengths in the medical field, The shape of the polymeric micelles is also important in drug delivery, Studies on in vitro drug release profiles require a good sink condition. The critical micelle concentration of a series of MePEG-PDLLA has a significant role in drug release. To estimate their feasibility as a drug carrier, polymeric micelles made of MePEG-PDLLA block copolymer were prepared by the oil in water （O/VV） emulsion method. From dynamic light scattering （DLS） measurements, the size of the micelle formed was less than 200 nm, The critical micelle concentration of polymeric micelles with various compositions was determined using pyrene as a fluorescence probe. The critical micelle concentration decreased with increasing number of hydrophobic segments. MePEG-PDLLA micelles have a considerably low critical micelle concentration （0.4～0.5 μg/mL）, which is apparently an advantage in utilizing these micelles as drug carriers. The morphology of the polymeric micelles was observed using scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, The micelles were found to be nearly spherical. The yield of the polymeric micelles obtained from the O/W method is as high as 85%.

Adsorption of Methanol and Methoxy on Cu（111） Surface： A First-principles Periodic Density Functional Theory Study

Adsorption of methanol and methoxy at four selected sites （top, bridge, hcp, fcc） on Cu（111） surface has been investigated by density functional theory method at the generalized gradient approximation （GGA） level. The calculation on adsorption energies, geometry and electronic structures, Mulliken charges, and vibrational frequencies of CH3OH and CH3O on clean Cu（111） surface was performed with full-geometry optimization, and compared with the experimental data. The obtained results are in agreement with available experimental data. The most favorite adsorption site for methanol on Cu（111） surface is the top site, where C-O axis is tilted to the surface. Moreover, the preferred adsorption site for methoxy on Cu（111） surface is the fcc site, and it adsorbs in an upright geometry with pseudo-C2v local symmetry. Possible decomposition pathways also have been investigated by transition-state searching methods. Methoxy radical, CH3O, was found to be the decomposition intermediate. Methanol can be adsorbed on the surface with its oxygen atom directly on a Cu atom, and weakly chemisorbed on Cu（111） surface. In contrast to methanol, methoxy is strongly chemisorbed to the surface.

Surface Modification of 316L Stainless Steel by Grafting Methoxy Poly（ethylene glycol） to Improve the Biocompatibility

Percutaneous coronary intervention（PCI） has become an important method for the treatment of the pa- tients with coronary heart disease; however, problems, such as vascular endothelial inflammation, late thrombosis, and stent restenosis still exist as a result of poor biocompatibility of the materials. To enhance the biocompatibility, methoxy poly（ethylene glycol）（mPEG） was immobilized on the surface of AISI 316 grade stainless steel（SS）（AISI： American Iron and Steel Institute）. First, silanized mPEG was synthesized by the direct coupling of mPEG with 3-isocyanatopropyltriethoxysilane（IPTS） via urethane bonds, and the silanized mPEG was then grafted on the surface of SS that was hydroxylated with piranha solution. The results obtained from contact angle goniometry, X-ray pho- toelectron spectroscopy（XPS）, and atomic force microscopy（AFM） confirm that the mPEG modified steel contained more C and Si and less Fe and Cr on its surface, exhibiting a morphological change and decrease in the contact angle. The biocompatibility of the mPEG modified SS was evaluated with fibrinogen adsorption, platelet activation and adhesion, and human umbilical vein endothelial celI（HUVEC） adhesion. Fibrinogen adsorption, platelet activation, and adhesion were clearly suppressed on the surface-modified steel. In addition, human umbilical vein endothelial cell（HUVEC） could adhere and proliferate on the surface of the mPEG-modified SS. This study indicates that the modification of 316L SS with mPEG could enhance the biocompatibility and provide a primary experimental founda- tion for the development of next-generation coronary stent materials for clinical application.

NEW EREMOPHILANOLIDES FROM LIGULARIA VEITCHIANA

The structures of three new eremophilanolides isolated from the roots of Ligularia Veitchiana were shown,by the spectral and chemical evidences,to be 1β,10β-epoxy-6β- hydrox-y-8β-methoxy-eremophil-7(11)-en-12,8α-olide(3),1β,10β-epoxy-6β- (2'-hydroxymethylacryloyloxy)-8β-methoxy-eremophil-7(11)-en-12,8α-olide (4)and 1β,10β-epoxy-6β-(2'-methoxymethylacryloyloxy)-8β-hydroxy-eremophil -7(11)-en-12,8α-olide(5).

Condensation reaction of formaldehyde and methyl formate catalyzed by a composite catalyst system

The condensation reaction of formaldehyde and methyl formate to form methyl glycolate and methyl methoxy acetate catalyzed by p-toluenesulfonic acid and different Lewis acid compounds has been investigated. The composite catalytic system consisting of p-toluenesulfonic acid and NiX2 （X = Cl, Br, I）, especially NiI2, exhibited a high catalytic performance for the condensation reaction, the total yield of MG and MMAc was up to 72.37%.

Catalytic Systems Containing p-Toluenesulfonic Acid for the Coupling Reaction of Formaldehyde and Methyl Formate

The coupling reaction of formaldehyde （FA） and methyl formate （MF） to form methyl glycolate （MG） and methyl methoxy acetate （MMAc）, catalyzed by p-toluenesulfonic acid （p-TsOH） as well as assisted by different kinds of solvents or Ni-containing compounds, had been investigated. The results showed that when the reaction was carried out at 140 ℃, with a molar ratio of FA to MF of 0.65 ： 1, molar fraction of p-TsOH to total feedstock of 11.0%, and reaction time of 3 h, the yield of MG and MMAc was 31.1% and 17.1%, respectively, p-TsOH catalyzed the coupling reaction by means of the synergistic catalysis of protonic acidity and soft basicity. Adding extra solvents to the reaction system was unfavorable for the reaction. The composite catalytic system consisting of p-TsOH and NiX2 （X=Cl, Br, I） exhibited a high catalytic performance for the coupling reaction, and NiX2 acted as a promoter in the reaction, whose promotion for the catalysis increased in the following order： NiCl2〈NiBr2〈NiI2. The present system is less corrosive when compared with the previous system, in which strong inorganic liquid acids were used as catalysts.

A New Tetranuclear Cubane-like Ni(Ⅱ) Complex Based on Schiff-base Ligand:Synthesis,Crystal Structure and Magnetic Properties

A new Ni（Ⅱ） cubane-like complex, namely, [Ni（L）（CH3OH）]4·（CH3OH）2, has been obtained via self-assembly of nickel（Ⅱ） and Schiff base, where the ligand L is a raceme of（R）-2-[（2-hydroxy-1-phenyl-ethylimino）-methyl]-6-methoxy-phenol. X-ray diffraction analysis reveals that the complex shows a cubane-like [Ni4O4] cluster and similar coordination environment around the metallic centers. Magnetic measurements indicate there is ferromagnetic interaction within the Ni4 cluster.

Study on Extraction of Pectin from Orange Peels

The comparison was conducted to investigate the higher extraction rate between two methods including alcohol deposition with acid hydrolysis and micro- wave-assistant extraction technique. The experimental results showed that the former method led to a better extraction effect. For the method of alcohol deposition with acid hydrolysis, the technique parameters were optimized through I.s （34 ） orthogonal e^periment based on the results of single factor experiments, after investi- gated the effect of solid to liquid ratio, pH, extraction temperature and extraction time on the pectin extraction rate. tersrm technique was employed to extract pectin. The selected parameter was obtained by means On the basis of the optimal technical parmne- of L16 （45） orthogonal experiment after studied the effect of solid to liquid ratio, extraction temperature, microwave treatment period, pH and microwave power on pectin extraction yield. Repetitive examinations of two methods were carried out separately, pectin extraction rate with the fLrst technique was 14.57% and that with the second method was 11.62%. The charac- teristics of the pectin sample prepared by alcohol deposition with acid hydrolysis were further investigated. The research demonstrated that mass percent of pectin was 87.23%. The esterification degree of pectin was 75.66% ,and pectin sample color was from creamy white to pale yellow.

Natural and Derivatized Acetogenins Promising for the Control of Spodoptera frugiperda Smith

Annonaceous acetogenins (ACG), belonging to the family Annonaceae, represent a class of bioactive compounds whose toxic effects have been reported for several spe-cies of insects. Given their insecticidal properties, we first carried out the isolation of the ACG from a Brazilian collection of the seeds of Annona squamosa (Annonaceae) and prepared their methoxy methylated (MOM) and acetylated (OAc) derivatives by chemical methods. ACG analogues were semi-synthesized and characterized by spec-troscopic techniques (1H and 13C-NMR). We isolated ten natural acetogenins: squamo-cin, molvizarin, motrilin, rolliniastatin-2, almunequin, cherimolin-1, cherimolin-2, an-nonacin, squamocin D and asiminecin. The main objective of this study is to report the antifeedant, toxic and nutritional effects of three of those natural acetogenins and their acetylated and methoxy methylated derivatives on Spodoptera frugiperda Smith (Lep-idoptera: Noctuidae). The natural ACGs squamocin and molvizarin killed 100% of S. frugiperda larvae, followed by motrilin (80%). Acetylated derivatives had less toxic and nutritional effects that led to pupal mortality and adult fatal malformations. The addition of MOM derivatives to the larval diet has not toxic effects on larvae, but significantly reduces growth rate and efficiency in conversion of ingested food into biomass, affecting adult survival.

Heteroatom engineering on spiro-type hole transporting materials for perovskite solar cells

A series of spiro-type hole transporting materials, spiro-OMe TAD, spiro-SMe TAD and spiro-OSMe TAD,with methoxy, methylsulfanyl or half methoxy and half methylsulfanyl terminal groups are designed and prepared. The impact of varied terminal groups on bulk properties, such as photophysical, electrochemical, thermal, hole extraction, and photovoltaic performance in perovskite solar cells is investigated.It is noted that the terminal groups of the hole transporting material with half methoxy and half methylsulfanyl exhibit a better device performance and decreased hysteresis compared with all methoxy or methylsulfanyl counterparts due to better film-forming ability and improved hole extraction capability.Promisingly, the spiro-OSMe TAD also shows comparable performance than high-purity commercial spiro-OMe TAD. Moreover, the highest power conversion efficiency of the optimized device employing spiro-OSMe TAD exceeding 20% has been achieved.