The inhibitory effect of intestinal bacterial metabolite of ginsenosides on CYP3A activity

The intestinal bacterial metabolites of ginsenosides are responsible for the main pharmacological activities of ginseng. The purpose of this study was to find whether these metabolites influence hepatic metabolic enzymes and to predict the potential for ginseng-prescription drug interactions. Utilizing the probe reaction of CYP3A activity, testosterone 6beta-hydroxylation, the effects of derivatives of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol families on CYP3A activity in rat liver microsomes were assayed. Our results showed that ginsenosides from the 20(S)-protopanaxadiol and 20(S)-protopanaxatriol family including Rb-1, Rb-2, Rc, Compound-K, Re, and Rg(1), had no inhibitory effect, whereas Rg(2), 20(S)-panaxatriol and 20(S)-protopanaxatriol exhibited competitive inhibitory activity against CVP3A activity in these microsomes with the inhibition constants (K) of 86.4+/-0.8mum, 1.7+/-0.1mum, and 3.2+/-0.2 mum, respectively. This finding demonstrates that differences in their chemical structure might influence the effects of ginsenosides on CYP3A activity and that ginseng-derived products might have potential for significant ginseng-drug interactions.

1,2,4-三氯苯胁迫对萌发大豆种子中活性氧的影响

以盆栽法研究了不同浓度 1,2 ,4 三氯苯 (TCB)胁迫对萌发大豆种子中活性氧代谢的影响 .结果表明 ,10 0～ 30 0 μg·g-1TCB胁迫初期 (1～ 3天 )促使萌发大豆种子呼吸强度升高及其峰值提前出现 ,超氧阴离子自由基 (O2 - )及过氧化氢 (H2 O2 )的积累显著增加 ,同时伴随丙二醛 (MDA)含量升高 ,显示发生膜脂质过氧化作用 .TCB胁迫 1～ 6天使活性氧清除酶功能紊乱 ,其中过氧化物酶 (POD)活性升高 ,超氧化物岐化酶 (SOD)活性开始上升后转为下降 .在萌发大豆种子受TCB胁迫伤害过程中 ,活性氧代谢失衡造成的膜脂质过氧化将起着重要作用 .

A 2-kW COIL with a square pipe-array JSOG and nitrogen buffer gas

A 2-kW-class chemical oxygen-iodine laser (COIL) using nitrogen buffer gas has been developed and tested since industrial applications of COIL devices will require the use of nitrogen as the buffer gas. The laser, with a gain length of 11.7 cm, is energized by a square pipe-array jet-type singlet oxygen generator (SPJSOG) and employs a nozzle bank with a designed Mach number of 2.5. The SPJSOG has advantages over the traditional plate-type JSOG in that it has less requirements on basic hydrogen peroxide (BHP) pump, and more important, it has much better operational stability. The SPJSOG without a cold trap and a gas-liquid separator could provide reliable operations for a total gas flow rate up to 450 mmol/s and with a low liquid driving pressure of around 0.7 atm or even lower. The nozzle bank was specially designed for a COIL using nitrogen as the buffer gas. The cavity was designed for a Mach number of 2.5, in order to provide a gas speed and static temperature in the cavity similar to that for a traditional COIL with helium buffer gas and a Mach 2 nozzle. An output power of 2.6 kW was obtained for a chlorine flow rate of 140 mmol/s, corresponding to a chemical efficiency of 20.4%. When the chlorine flow rate was reduced to 115 mmol/s, a higher chemical efficiency of 22.7% was attained. Measurements showed that the SPJSOG during normal operation could provide a singlet oxygen yield Y greater than or equal to 55%, a chlorine utilization U greater than or equal to 85%, and a relative water vapor concentration w = [H2O]/([O-2] + [Cl-2]) less than or equal to 0.1.

森林流域洪涝灾害成因分析与防治对策

森林流域洪涝灾害成因分析与防治对策孙铁珩，裴铁璠张吉娜（中国科学院沈阳应用生态研究所）（辽宁省生态学会）本文所述的森林流域是广义的，系指我国典型敏感带以东广大地区。典型敏感带始于东北西部内蒙东部向西南一直延伸到青藏高原东南部。它是干旱、半干旱与湿润、...

四氯乙烯和对二氯苯对草鱼的联合毒性

采用水生污染暴露试验和水生毒理联合效应相加指数法,研究了四氯乙烯(PCE)和对二氯苯(P-DCB)对草鱼(Ctenopharyngodon idellus)的单一毒性与联合毒性.结果表明,PCE和P-DCB的单一毒性均为高毒,且P-DCB的毒性大于PCE.PCE和P-DCB对草鱼的联合染毒在浓度1:1时,暴露时间为24,48,72,96h的相加指数(AI)分别为0.26,0.37,0.78,0.98,联合毒性为相加作用.PCE与P-DCB对草鱼的联合染毒在毒性1:1时,暴露时间为24,48,72,96h的AI分别为-0.15,0.24,0.83,1.30,联合毒性主要是相加作用,但是随着染毒时间的延长,联合毒性由相加作用向协同作用转变.

Guest inducing p-sulfonatocalix[4] arene into three-dimensional capsule architecture and a mixed A-B double layer framework

The reactions of sodium p-sulfonatocalix[4]arene (Na5L) and terbium/europium(III) chloride in the presence of pyrazine-N,N'-dioxide (PNNO) in aqueous solutions gave the crystalline complexes 1 and 2. Both structures contain molecular capsules of p-sulfonatocalix[4] arene with PNNO as guest molecules in the cavity of the calix[4]arenes. The molecular capsules are connected through sodium and terbium (or europium) centers forming a three-dimensional framework.

Influence of Polyelectrolyte on DNA-RecA Nucleoprotein Filaments: Poly-L-Lysine Used as a Model

RecA of Escherichia coli and its active nucleoprotein filaments with DNA are important for the genomic integrity and the genetic diversity. The formation of the DNA-RecA nucleoprotein filaments is a complex multiple-step process and can be affected by many factors. In this work, the effects of poly-L-lysine (PLL) on the DNA-RecA nucleoprotein filaments are investigated in vitro by agarose gel electrophoresis and atomic force microscopy (AFM). The observed morphologies vary with the concentration, the length, and the addition order of PLL. These distinctions provide information for the conformation change of DNA and the binding sites of RecA protein in the formation process of nucleoprotein filaments.

Vibronic transitions and site substitution of Eu2+ and codoped ions in KMgF3 : Eu-X (X=Ce, Cr, Gd, Cu) system

The high-resolution emission spectra of KMgF3 : Eu and KMgF3 : Eu-X(X = Ce, Cr, Gd, Cu) single crystals were measured at 300 and 77 K. The vibronic side bands of Eu2+ were characterized and an assignment of the normal mode frequencies to particular vibrations has been made. The correlation between the vibronic frequencies of Eu2+ and the site substitution of other co-dopcd ions was first found. The relationship between vibronic intensity of Eu2+ and other doped ions concentration showed that Cr3+, Gd3+ ions competed K+ sites with Eu2+ ions. Ce3+ and Eu3+ occurred the electron transference. The introduction of Cu+ made for Eu2+ substuting for K+ sites.

KMgF_3∶Eu,X(X=Ce,Cr,Gd,Cu)体系中Eu~(2+)振动光谱和共掺离子的格位取代

测定了一系列单掺杂 Eu2 +和双掺杂 Eu,X( X=Ce,Cr,Gd,Cu)的 KMg F3晶体在 30 0 K和 77K的高分辨发射光谱以及伴随的振动光谱 ,据此研究了 Eu2 + 在这些体系中的振动跃迁特征 ,并指认了每一振动峰所对应的正则振动模式 .首次发现了在共掺杂体系中 Eu2 +振动频率与其它掺杂离子格位取代间的相关性

α-羰基烯酮式环二硫代缩醛化学(V)——β,β-1,3-亚丙二硫基-α,β-不饱和芳酮类化合物的合成

β,β-二烷硫基-α,β-不饱和酮类化合物作为一类具多反应中心的活泼中间体在有机合成中的应用,近20年来已引人注目并进行了深入广泛的研究~[1,2].以往的研究大多是针对β,β-二甲硫基-α,β-不饱和酮类化合物1进行的,而对结构相近的β,β-1,3-亚丙二硫基-α,β-不饱和酮类化合物2的研究较少.对于1类的合成,所用碱的选择至关重要~[1].实验证明叔丁醇钠和叔丁醇钾~[3～5]在1类的合成中效果较好.前文~[6]曾以六甲基二硅氨基锂(LHMDS)为碱高

Benzaldehyde derivatives from Eurotium rubrum, an endophytic fungus derived from the mangrove plant Hibiscus tiliaceus

Four new (1-4) and seven known (5-11) benzaldehyde derivatives were characterized from the liquid fermentation cultures of Eurotium rubrum, an endophytic fungus that was isolated from the inner tissue of stems of the mangrove plant Hibiscus tiliaceus. The structures of these compounds were determined by extensive analysis of their spectroscopic data. Among these metabolites, compound 1, which was named as eurotirumin, possesses a new carbon skeleton with a cyclopentabenzopyran ring system.