Effect of ginseng saponins on the survival of cerebral cortex neurons in cell cultures

The effects of nerve growth factor (NGF) and saponins isolated from Panax ginseng C.A. Mayer on the survival of chick and rat embryonic cerebral cortex neurons were examined. Ginsenoside Rg1 (GRg1) exerted a survival-promoting effect on both chick and rat cerebral cortex neurons in cell cultures. Ginsenoside Rb1 (GRb1) also had an effect in the rat and displayed some influence in the chick. NGF alone exerted no effect on both neurons, although it did potentiate the GRb1 effect on chick embryonic cerebral cortex neurons, but did not alter the GRb1 effect on rat embryonic cerebral cortex neurons. NGF did not alter the survival-promoting effect of GRg1 on either chick or rat embryonic cerebral cortex neurons. The other saponins alone or with NGF exerted no effect on the survival of cerebral cortex neurons in either the chick or rat.     

Inhibition effects of gangliosides G(M1), G(D1a) and G(T1b) on base-catalyzed isomerization of prostaglandin A(2)

Micellar inhibition effect of gangliosides on a degradation of drug was investigated, where ganglioside G(M1) (GM1), G(D1a) (GD1a) and G(T1b) (GTlb) whose sialic acid residue is one, two and three, respectively, were used. The base-catalyzed isomerization of prostaglandin A(2) (PGA(2)) to prostaglandin B(2) (PGB(2)) was chosen as a model experiment. The rate for the isomerization of PGA(2) was determined by measuring the concentration of PGA(2) (and PGB(2)) with a high-performance liquid chromatography. Gangliosides micelles inhibited the isomerization of PGA(2). The inhibition effect of GT1b micelles was larger than that of GD1a micelles. This result would be due to the larger absolute value of surface potential of GT1b micelles, which brings about a larger electrostatic repulsion between micellar surface and OH(-). The terminal sialic acid residue of ganglioside was effective to inhibit the isomerization of PGA(2). GM1 micelles without terminal sialic acid residue but with large aggregation number exhibited a superior steric shielding effect rather than an electrostatically repulsive effect. The inhibition effect of GM1 micelles was enhanced by the mixed micellization with the other ganglioside with a terminal sialic acid residue. GM1-GD1a or GM1-GT1b mixed micelles remarkably inhibited the isomerization of PGA(2). The physiological activity of PGs in the biological membranes containing gangliosides was also discussed.     

Peculiar effects of alkali thiocyanates on the activity coefficients of aromatic hydrocarbons in water

Among twenty-two 1:1 electrolytes examined, LiSCN, CsSCN, KSCN and CsI have a considerable effect on the aqueous solubilities of a series of nonelectrolytes. LiSCN shows a salting-in effect for all the nonelectrolytes examined including 1-octanol, benzene, naphthalene and biphenyl while CsSCN and CsI show a salting-out effect for 1-octanol but a salting-in effect for all the aromatic hydrocarbons. The effect of NaSCN and KSCN on the solubilities of naphthalene and biphenyl results in an anomalous concentration depencence, i.e., both salting-in and salting-out effects occur depending upon the electrolyte concentration. It is suggested that the anomalous salt effects may partly be explained through perturbation of preexisting ion-ion structural hydration interaction upon introduction of the solute molecules.     

Packing Effect on Mixed-Valence States of 1′,1′′′-Dialkyl- and 1′,1′′′-Bis(Methylbenzyl)Biferrocenium Triiodides

Abstract

A remarkable packing effect on the mixed-valence state was observed in 1′, 1′′′-diisobutylbiferrocenium triiodide. The effect was also observed for a series of 1′,1′′′-dialkyl- and 1′,1′′′-bis(methylbenzyl)biferrocenium triiodides by means of ESR spectroscopy.     

3-氨基-1,2,4-三氮唑和Na2 WO4复合缓蚀剂对黄铜的缓蚀协同作用

应用交流阻抗和极化曲线测试3-氨基-1,2,4-三氮唑(ATA)和钨酸钠复合缓蚀剂对黄铜在3%NaCl溶液中的缓蚀作用.结果表明,ATA对黄铜有缓蚀作用,并以7.5 mg.L-1ATA的缓蚀效果最好,缓蚀率为87.46%,以7.5 mg.L-1ATA和0.15 mg.L-1Na2WO4配成复合缓蚀剂则对黄铜具有很好缓蚀协同效应,缓蚀效率达91.82%,属阴极型缓蚀剂.     

水溶性树枝形聚合物微反应器笼效应研究

本工作以羧基为末端基团的芳醚树枝形聚合物G_n(n=1-4)和核心为十二烷基链的聚酰胺-胺树枝形聚合物PG_m(m=1-3)作为光化学微反应器,研究了1-苯基-3-对甲苯基丙酮在水溶液中的α-光解反应,并计算了笼效应.研究结果表明,芳醚树枝形聚合物G_n的笼效应随代数增加而增大,高代数树枝形聚合物表现出对底物分子更强的限制性作用,增加树枝形聚合物的浓度可以提高笼效应;聚酰胺-胺树枝形聚合物PG_m对CH₃-DBK的限制作用远低于芳醚树枝形聚合物G_n.     

Polarographic study of N-phenylbenzimidazolium,N-phenylperimidinium,and naphth[2,3-d] imidazolium ions

The effect of the N-phenyl group on the ease and character of the polarographic reduction of benzimidazolium and perimidinium ions was studied. The effect of the introduction of a phenyl group in the 1 position of the benzimidazolium cation is approximately equal to the effect of a benzene ring condensed in the 5 and 6 positions and considerably exceeds the effect of a phenyl group introduced in the 2 position and of a benzene ring condensed in the 4 and 5 positions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 110–113, January, 1979.The authors thank A. A. Konstantinchenko for the synthesis of 1-phenyl-3-methylperimidinium iodide and perchlorate.     

脂族酰基过氧化物分解动力学的分研究 III: 过氧化3,5,5-三甲基己酰在萃中的解动力学和机理

The kinetics of decomposition of 3, 5, 5-trimethylhexanoyl peroxide (1) in benzene has been studied at 30, 40 and 50`C and the cage effect of decomposition has been determined by scavenging method. The relative amounts of the main products of decomposition of 1 at 50`C with change of initial concentration have been determined. The results showed that the decomposition of 1 followed first plus three halves order kinetics as reported for lauroyl peroxide (2), but had a larger cage effect of 0.6. The mechanism of decomposition of 1 is practically the same as what we have proposed for 2. The faster rate and larger cage effect but less induced decomposition of 1 than that of 2 are attributed to the branching of the molecule of 1, especially to the presence of β-methyl group, which causes a larger entropy increase in the transition state.     

复方排铅口服液治疗铅高婴幼儿166例

用已经过动物实验或临床试验证实有排铅、提高免疫功能、提高智力和强身健体作用的维生素C、维生素B1、氨基酸和有机锌、Ge-132等配成的复方排铅口服液,治疗经发铅检查铅高的婴幼儿166例,疗程1－2个月,显效率65.1％、总有效率95.8％,临床疗效比较理想。     

十二烷基季铵盐及其与十二烷基硫酸钠混合体系的表面活性

通过表面张力测定，研究了十二烷基季铵盐Ｃ１２Ｈ２５Ｎ（ＣｎＨ２ｎ＋１）３Ｂｒ（ｎ＝１，２，３，４）及其与十二烷基硫酸钠混合体系的表面活性，应用规则溶液理论，计算了混合体系表面吸附层和胶团的组成及分子相互作用参数，对于季铵盐、极性基影响大：ｃｍｃ随ｎ增加而下降，γｃｍｃ则先上升，后下降，自极性基碳链的空间阻碍、疏水、弯曲效应，以及电荷屏蔽效应可对此予以解释，对于混合体系，极性基大小对其表面活性及胶团     

The Role of Monosialoganglioside GM1 in LTP-Induction in Rat Hippocampal Slices

The effect of monosialoganglioside GM1 of different doses on the long-term potentiation (LTP) of synaptic transmission has been studied in the CA1 region of rat hippocampal slices, and the possible role that calcium ion and NMDA receptor play has also been investigated. The results reveal that larger magnitude of LTP is induced in hippocampal slices pre-incubated with GM1. The dose-response curve appears in diphase, and the largest magnitude of LTP has been obtained at the GM1 concentration of 50 mg/L in incubation ACSF. Moreover, the magnitude of LTP induced from the slices pre-incubated with GM1 at lower calcium ion concentration is similar to that obtained from the control slices at normal calcium ion concentration. Under higher calcium ion concentration, the enhancing effect of GM1 on LTP seems relatively feeble. After NMDA receptors were blocked, no enhancing effect of GM1 was observed. The mechanism of GM1 action on LTP is discussed.     

Mechanism of interaction of substituents in bicycloalkane compounds

The mechanism of interaction of substituents in the 4-substituted bicyclo[2.2.2]oct-1-ylfluorides and bicyclo[2.2.1]hept-1-ylfluorides based on the inductive effect and the positive charge effect was studied.     

Is there a generalized reverse anomeric Effect? substituent and solvent effects on the configurational equilibria of neutral and protonated N-arylglucopyranosylamines and N-aryl-5-thioglucopyranosylamines

The effects of substitution and solvent on the configurational equilibria of neutral and protonated N-(4-Y-substituted-phenyl) peracetylated 5-thioglucopyranosylamines (Y = OMe, H, CF(3), NO(2)) 1-4 and N-(4-Y-substituted-phenyl) peracetylated glucopyranosylamines (Y = OMe, H, NO(2)) 9-11 are described. The configurational equilibria were determined by direct integration of the resonances of the individual isomers in the (1)H NMR spectra after equilibration of both alpha- and beta-isomers. The equilibrations of the neutral compounds 1-4 in CD(3)OD, CD(3)NO(2), and (CD(3))(2)CO were achieved by HgCl(2) catalysis and those of the neutral compounds 9-11 in CD(2)Cl(2) and CD(3)OD by triflic acid catalysis. The equilibrations of the protonated compounds in both the sulfur series (solvents, CD(3)OD, CD(3)NO(2), (CD(3))(2)CO, CDCl(3), and CD(2)Cl(2)) and oxygen series (solvents, CD(2)Cl(2) and CD(3)OD) were achieved with triflic acid. The substituent and solvent effects on the equilibria are discussed in terms of steric and electrostatic effects and orbital interactions associated with the endo-anomeric effect. A generalized reverse anomeric effect does not exist in neutral or protonated N-aryl-5-thioglucopyranosylamines and N-arylglucopyranosylamines. The anomeric effect ranges from 0.85 kcal mol(-)(1) in 2 to 1.54 kcal mol(-)(1) in 10. The compounds 1-4 and 9-11 show an enhanced endo-anomeric effect upon protonation, ranging from 1.73 kcal mol(-)(1) in 2 to 2.57 kcal mol(-)(1) in 10. We estimate the increase in the anomeric effect upon protonation of 10 to be approximately 1.0 kcal mol(-)(1). However, this effect is offset by steric effects due to the associated counterion which we estimate to be approximately 1.2 kcal mol(-)(1). The values of K(eq)(axial-equatorial) in protonated 1-4 increase in the order OMe < H < CF(3) < NO(2), in agreement with the dominance of steric effects (due to the counterion) over the endo-anomeric effect. The values of K(eq)(axial-equatorial) in protonated 9-11 show the trend OMe > H < NO(2) that is explained by the balance of the endo-anomeric effect and steric effects in the individual compounds. The trends in the values of the C(1)-H(1) coupling constants for 1-4 and the corresponding deacetylated compounds 5-8 as a function of substituent and alpha- or beta-configuration are discussed in terms of the Perlin effect and the interplay of the endo- and exo-anomeric effects.     

煤焦油中酚类物质对焦油组分加氢脱氮脱硫以及芳烃饱和的影响

在固定床加氢微反装置上,考察了邻甲酚对煤焦油组分喹啉加氢脱氮(HDN)反应、二苯并噻吩(DBT)加氢脱硫(HDS)反应以及1-甲基萘加氢饱和(HDA)反应的影响。结果表明,邻甲酚的加入对喹啉的HDN反应、DBT的HDS反应、1-甲基萘的HDA反应有着较强的抑制作用,且邻甲酚的含量越多,这种抑制作用越明显,这是由于邻甲酚与喹啉、DBT、1-甲基萘在活性位点上的竞争吸附造成的。邻甲酚的加入对产物的选择性影响较弱,反应前后产物的选择性变化很小。由于空间位阻效应,1-甲基萘的加氢优先发生在不带侧链的芳环上。     

Determination of singlet oxygen quenching and protection of biological systems by various extracts from seed of Rumex crispus L

The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effect and total phenolic contents were evaluated for the screening of singlet oxygen ((1)O(2)) quenching efficacy of various seed extracts from Rumex crispus L. The butanol and ethyl-acetate extracts displayed remarkable effect of DPPH as compared to positive control ascorbic acid. The concentrations (QC(50)) of butanol and ethyl-acetate extracts required to exert 50% reducing effect on (1)O(2) were found to be 116 and 82 μg mL(-1), respectively. Both extracts were also found to protect the in vitro biological system from the detrimental effect of (1)O(2) on type II photosensitization in Escherichia coli, red blood cell, lactate dehydrogenase and histidine. Among all the tested extracts, the ethyl-acetate and butanol extracts contained higher amount of total phenolic contents. The results suggest that our study may contribute to the development of new bioactive products with potential applications to reduce photo-produced oxidative stress involving reactive oxygen species in living organisms.     

The Lipophilic Purine Nucleoside—Tdp1 Inhibitor—Enhances DNA Damage Induced by Topotecan In Vitro and Potentiates the Antitumor Effect of Topotecan In Vivo

The use of cancer chemotherapy sensitizers is a promising approach to induce the effect of clinically used anticancer treatments. One of the interesting targets is Tyrosyl-DNA Phosphodiesterase 1 (Tdp1), a DNA-repair enzyme, that may prevent the action of clinical Topoisomerase 1 (Top1) inhibitors, such as topotecan (Tpc). Tdp1 eliminates covalent Top1-DNA (Top1c) complexes that appear under the action of topotecan and determines the cytotoxic effect of this drug. We hypothesize that Tdp1 inhibition would sensitize cells towards the effect of Tpc. Herein, we report the synthesis and study of lipophilic derivatives of purine nucleosides that efficiently suppress Tdp1 activity, with IC₅₀ values in the 0.3–22.0 μM range. We also showed that this compound class can enhance DNA damage induced by topotecan in vitro by Comet assay on human cell lines HeLa and potentiate the antitumor effect of topotecan in vivo on a mice ascitic Krebs-2 carcinoma model. Thereby, this type of compound may be useful to develop drugs, that sensitize the effect of topotecan and reduce the required dose and, as a result, side effects.     

Synthesis of Pt-SnOx/TS-1@SBA-16 Composites and Their High Catalytic Performance for Propane Dehydrogenation

A novel composite material of TS-1@SBA-16 was synthesized by enwrapping TS-1 zeolite crystals with mesoporous SBA-16 silica. This composite was used as catalyst support for loading Pt-SnOx in the propane dehydr genation(PDH) reaction. Catalysts were characterized by means ofN2 adsorption-desorption, XRD, SEM, TEM, XPS, UV-Vis, and Raman spectroscopy. The effect of different contents of TS-1 on PDH was investigated, and the optimal amount of TS-1 was determined to be 10%. The catalyst with TS-1 content of 10% showed the highest PDH activity and the initial conversion of propane over it can achieve 54.5%, higher than those over TS-1 or SB A-16-supported ones. The superior catalytic performance of Pt-SnOx/TS-1 @SBA-16 is related to the synergistic effect of the excellent mass transfer performance through the hierarchical porous structure, suitable acid acidity and electronic effect of Ti species.     

Synthetic studies of vitamin D analogues. X. Synthesis and biological activities of 1 alpha,25-dihydroxy-21-norvitamin D3.

1 alpha,25-Dihydroxy-21-norvitamin D3 (3) was synthesized from 1 alpha-hydroxydehydroepiandrosterone (4). Certain biological properties of 3 were examined in comparison with those of 1 alpha,25-dihydroxyvitamin D3 (1) and 1 alpha,25-dihydroxy-21-nor-20-oxavitamin D3 (2) to evaluate the effect of the 21-methyl substituent on biological activities. The differentiation-inducing activity of 3 towards human myeloid leukemia cells was approximately one-fifth of that of 1, while in the binding affinity with chick intestinal cytosolic receptor, 3 was about one-tenth of that of 1. The rather weak effect of 3 on serum calcium levels in normal mice at a dosage of 500 micrograms/kg (intravenous administration) indicates that the essential importance of the 21-methyl moiety may lie in its effect on the regulation of calcium metabolism.     

Effect of sulfur coverage on Fe(110) adhesion: a DFT study

The effect of adsorbed S at different coverages on the adhesion of Fe(110) surfaces in match and mismatch is examined using density functional theory (DFT). S is adsorbed in atop, bridge, and 4-fold hollow sites on one side of the interface in c(2 x 2) and p(1 x 1) arrangements, corresponding to coverages of 1/2 and 1 monolayer, respectively. The calculated adhesion energy values at different interfacial separations are fitted to the universal binding energy relation, and the effect of the S coverages on the adhesive strength is analyzed. The effect of relaxation of the interfaces at equilibrium is also investigated, and the resulting interfacial structures and related magnetic and charge density properties are compared.     

Catalytic spectrophotometric determination of tungsten using the malachite green-Ti(III) redox reaction and a thiocyanate activator

Thiocyanate was found to have a highly activating effect on the tungsten-catalyzed reaction of malachite green with Ti(III). A highly sensitive, selective and simple method was developed for the determination of tungsten based on this effect. The reaction rate was monitored spectrophotometrically by measuring the change in absorbance at 616 nm using a fixed time method. The effect of different parameters was studied and optimum conditions were established. The calibration graph was linear in the range of 1.2-10 and 10-80 ngml(-1). The detection limit was 0.15 ngml(-1) and relative standard deviation for ten replicate measurements of 1.2 ngml(-1) of tungsten was 1.8%. The proposed method was applied successfully for the determination of tungsten in hot spring waters.