苦参生物碱杀虫生物活性测定

以桃蚜等9种试虫为供试靶标，研究了苦参根提取物和苦参碱、氧化苦参碱、槐果碱、野靛碱的杀虫活性。试验结果表明：苦参生物碱具有一定的杀虫活性，9种试虫中，苦参根提取物对蚜虫的活性最高，其对蚕豆蚜的LC50为20．635mg／L；即使在最高剂量为4000mg/L时，也不能直接杀死粘虫、小菜蛾和棉铃虫。4种生物碱对朱砂叶螨活性均较低，LC50均大于2500mg／L。野靛碱是4种生物碱中杀虫活性最高的，对淡色库蚊、桃蚜、蚕豆蚜、褐飞虱和家蝇的LC50分别为172．431mg/L、207．667mg／L、85．212mg／L、266．179mg／L和763．224mg／L；而且对褐飞虱、桃蚜和家蝇的活性高于苦参根提取物，苦参碱对蚜虫的活性高于氧化苦参碱和槐果碱，槐果碱对淡色库蚊、褐飞虱和家蝇的活性高于苦参碱和氧化苦参碱。     

Synthesis and Antiplasmodial Activity of Novel Chloroquine Analogues with Bulky Basic Side Chains

Chloroquine is commonly used in the treatment and prevention of malaria, but Plasmodium falciparum, the main species responsible for malaria‐related deaths, has developed resistance against this drug. Twenty‐seven novel chloroquine (CQ) analogues characterized by a side chain terminated with a bulky basic head group, i.e., octahydro‐2H‐quinolizine and 1,2,3,4,5,6‐hexahydro‐1,5‐methano‐8H‐pyrido[1,2‐a][1,5]diazocin‐8‐one, were synthesized and tested for activity against D‐10 (CQ‐susceptible) and W‐2 (CQ‐resistant) strains of P. falciparum. Most compounds were found to be active against both strains with nanomolar or sub‐micromolar IC₅₀ values. Eleven compounds were found to be 2.7‐ to 13.4‐fold more potent than CQ against the W‐2 strain; among them, four cytisine derivatives appear to be of particular interest, as they combine high potency with low cytotoxicity against two human cell lines (HMEC‐1 and HepG2) along with easier synthetic accessibility. Replacement of the 4‐NH group with a sulfur bridge maintained antiplasmodial activity at a lower level, but produced an improvement in the resistance factor. These compounds warrant further investigation as potential drugs for use in the fight against malaria.     

两种苦豆子生物碱对昆虫酯酶同功酶的影响

金省花碱和苦豆碱是从豆科植物苦豆子中分离出来的两种喹诺里西定类生物夏威夷 聚丙烯酰胺凝胶电泳分析，两种生物碱对酯酶同功酶有显著的抑制作用，可为分析其对昆虫的作用机制时参考。     

苦参生物碱抑菌生物活性测定

以葡萄白腐病菌等19种病菌为供试靶标，测定了3%苦参碱水剂和苦参碱、氧化苦参碱、槐果碱、野靛碱的抑菌活性。离体试验结果表明：苦参生物碱具有一定的抑菌活性，当浓度为100mg/L时，3％苦参碱水剂的抑菌活性可达80％以上，对供试的病菌其EC50为28～48mg/L。苦参碱、氧化苦参碱、槐果碱和野靛碱具有不同的抑菌活性，4种生物碱对黄瓜黑星病菌、苹果轮纹病菌、葡萄白腐病菌和番茄灰霉病菌几乎没有抑菌活性，对其它病菌，氧化苦参碱的抑菌活性大多高于其它3种生物碱；野靛碱的抑菌活性最低，对各病菌的抑菌率均未超过10％。室内活体抑菌试验结果表明当剂量为800mg/L时，各药剂对水稻纹枯病病菌和小麦白粉病病菌均没有抑制作用，3％苦参碱水剂、氧化苦参碱和野靛碱对黄瓜灰霉病表现出了抑制作用，3%苦参碱水剂、苦参碱和槐果碱具有较高的抑制黄瓜霜霉病病菌的活性，防效达80％以上，野靛碱对其也有一定的抑制作用。     

HPLC测定牧马豆中不同部位金雀花碱的含量

目的建立测定牧马豆药材不同部位金雀花碱的RP-HPLC的方法。方法以Agilent C₁₈色谱柱（250 mm×4.6 mm,5μm）为分析柱,乙腈-0.02%醋酸铵-三乙胺（15:85:0.02）为流动相,检测波长230 nm,柱温40℃。结果进样量在0.35～1.75μg范围,金雀花碱峰面积与浓度呈良好线性关系（r=0.999 9）,回收率98.2%（n=6）。结论此法简便、快速、准确,可用于测定该药材中金雀花碱的含量。     

Förster Resonance Energy Transfer (FRET) Correlates of Altered Subunit Stoichiometry in Cys-Loop Receptors, Exemplified by Nicotinic α4β2

We provide a theory for employing Förster resonance energy transfer (FRET) measurements to determine altered heteropentameric ion channel stoichiometries in intracellular compartments of living cells. We simulate FRET within nicotinic receptors (nAChRs) whose α4 and β2 subunits contain acceptor and donor fluorescent protein moieties, respectively, within the cytoplasmic loops. We predict FRET and normalized FRET (NFRET) for the two predominant stoichiometries, (α4)₃(β2)₂ vs. (α4)₂(β2)₃. Studying the ratio between FRET or NFRET for the two stoichiometries, minimizes distortions due to various photophysical uncertainties. Within a range of assumptions concerning the distance between fluorophores, deviations from plane pentameric geometry, and other asymmetries, the predicted FRET and NFRET for (α4)₃(β2)₂ exceeds that of (α4)₂(β2)₃. The simulations account for published data on transfected Neuro2a cells in which α4β2 stoichiometries were manipulated by varying fluorescent subunit cDNA ratios: NFRET decreased monotonically from (α4)₃(β2)₂ stoichiometry to mostly (α4)₂(β2)₃. The simulations also account for previous macroscopic and single-channel observations that pharmacological chaperoning by nicotine and cytisine increase the (α4)₂(β2)₃ and (α4)₃(β2)₂ populations, respectively. We also analyze sources of variability. NFRET-based monitoring of changes in subunit stoichiometry can contribute usefully to studies on Cys-loop receptors.     

HPLC测定牧马豆中不同部位金雀花碱的含量

目的建立测定牧马豆药材不同部位金雀花碱的RP-HPLC的方法。方法以Agilent C18色谱柱（250mm）〈4．6mnq,5μm）为分析柱,乙腈-0．02％醋酸铵-三乙胺（15：85：0．02）为流动相,检测波长230nm,柱温40℃。结果进样量在0．35-1．75μg范围,金雀花碱峰面积与浓度呈良好线性关系（r=0．9999）,回收率98．2％（＂=6）。结论此法简便、快速、准确,可用于测定该药材中金雀花碱的含量。