高效液相色谱法测定氯洁霜中丙酸氯倍他索的含量

目的 建立HPLC法测定氯洁霜中丙酸氯倍他索的含量。方法 采用Kromasil C₁₈(150 mm×4.6 mm,5μm),以甲醇-水(74∶26)为流动相,检测波长240 nm。结果 丙酸氯倍他索在9.02～54.15μg·ml^-1范围内线性关系良好;回归方程C=1.357×10^-7A-5.371×10^-4(r=0.9999),平均回收率为101.2%,RSD为0.69%(n=12)。结论 该方法稳定、可靠,可用于测定氯洁霜中丙酸氯倍他索的含量,控制该制剂质量。     

定量核磁共振技术测定注射用丹参多酚酸中咖啡酸、丹参素、原儿茶酸和阿魏酸

目的 建立定量核磁共振技术(qNMR)同时测定注射用丹参多酚酸中咖啡酸、丹参素、原儿茶酸和阿魏酸。方法 通过qNMR测定4种单体酚酸，脉冲序列^zg30抑制水峰，谱宽设定8 012.8 Hz，温度为25℃，采样点数为131 072，采集时间为4.09 s，弛豫延迟时间为8.26 s，纵向弛豫时间为1.25 s；采样次数为16，接收器增益值为35.6，数字化仪分辨率值为18，空扫次数为4，发射机频率偏移为6.0×10^-6。以三氟乙酸-d为内标，根据峰面积比与质量比计算4种单体酚酸的含量。结果 咖啡酸、丹参素、原儿茶酸、阿魏酸分别选取9.47×10^-6(s，H-7)、8.02×10^-6(s，H-8)、5.86×10^-6(s，H-8)、12.79×10^-6(s，H-8)处的信号为定量峰；分析物在12 h后稳定性较差，所有样品在制备后12 h内完成测定；咖啡酸在0.103～1.625 μg·mL^-1(r²=0.999 3)，丹参素在2.256～3.194 μg·mL^-1(r²=0.999 5)，原儿茶酸在9.699～13.584 μg·mL^-1(r²=0.999 8)，阿魏酸在1.566～2.649 μg·mL^-1(r²=0.999 6)均呈良好的线性关系；加样回收率分别为104.9%、101.5%、104.1%、101.4%，RSD值分别为1.6%、2.1%、2.3%、1.5%；精密度、准确性、重复性均良好。结论 建立的qNMR可同时测定注射用丹参多酚酸中咖啡酸、丹参素、原儿茶酸和阿魏酸。     

HPLC-荧光法测定人血浆中羟基喜树碱的两种构型及其相互间的转化

目的 建立高效液相色谱法(HPLC)测定人血浆中羟基喜树碱两种活性成分盐型羟基喜树碱(C-HCPT)和酯型羟基喜树碱(L-HCPT)含量的方法,并且对两者之间的相互转化进行了初步研究。方法 采用HPLC-荧光法,Lichrospher C₁₈色谱柱,流动相为乙腈-0.075 mol·L^-1醋酸铵缓冲液(32∶68,pH 6.4),流量1.0 ml·min^-1,检测器激发波长为363 nm,发射波长为530 nm,内标法计算药物浓度。结果 人血浆样品中C-HCPT、L-HCPT峰分离良好,内源性杂质不干扰样品峰,最低检测浓度均为5 ng·ml^-1。C-HCPT、L-HCPT浓度范围在15～2000 ng·ml^-1间呈线性相关,回归方程分别为Y₁=9.393×10^-4X₁-9.1×10^-6和Y₂=1.0207×10^-3X₂-3.4×10^-6,相关系数分别为r₁=0.9997和r₁=0.9998,相对回收率分别为96.79%～119.64%和100.23%～112.93%,日内和日间变异均小于10%。两者之间的转化具有一定规律性;C-HCPT标准血样-20℃冻存20 d稳定,L-HCPT标准血样的稳定性有待进一步研究。结论 本方法专属性强，灵敏、可靠，适用于HCPT 类制剂给药后血药浓度的监测和体内的药代动力学特征研究；有关两者相互转化的机制及L-HCPT 稳定性问题尚待进一步深入研究。     

马蔺子素的单扫描示波极谱法测定

目的建立测定马蔺子素的极谱法。方法单扫描示波极谱法。结果在8.0×10^-3 mol·L^-1 Na₂B₄O₇-1.6×10^-2 mol·L^-1 KH₂PO₄ (pH 7.7)支持电解质中,马蔺子素有一灵敏的极谱还原波,其峰电位E_p=-1.23 V(vs SCE),二阶导数峰电流i_p″与马蔺子素浓度为1.5×10^-7～5.2×10^-6 mol·L^-1呈良好线性关系(γ=0.9992,N=9),检出限为6.0×10^-8 mol·L^-1。13次测量2.0×10^-6 mol·L^-1马蔺子素还原波二阶导数峰峰电流,相对标准偏差RSD为0.87%。结论该方法灵敏、简便、快速,可用于原料药及胶囊中马蔺子素含量的测定。     

基于溶解氧乙酰螺旋霉素极谱平行催化氢波的研究

目的提出一种极谱测定乙酰螺旋霉素(ASPM)的新方法。方法应用单扫描极谱法,在含溶解氧的0.1 mol·L^-1 NH₄Cl-NH₃·H₂O(pH 8.9)缓冲液中ASPM产生1个灵敏的平行催化氢波［峰电位E_p=-1.63 V(vs SCE)］。结果该平行催化氢波的二阶导数峰峰电流i″与ASPM浓度在1.74×10^-3～3.48 μg·mL^-1呈良好线性关系(r=0.997 9,n=13),检出限为5.80×10^-4 μg·mL^-1(3σ)。对0.871 μg·mL^-1 ASPM溶液进行13次平行测定,RSD为1.24%。结论本方法可用于ASPM片剂中ASPM含量的测定。     

RP-HPLC法测定注射用羟喜树碱脂质体含量

目的建立测定注射用羟喜树碱脂质体含量的方法。方法采用反相高效液相色谱法。色谱系统为ODS柱,以甲醇-水(60∶40)为流动相,检测波长为266 nm。结果本品在5.886~10.930μg.ml-1范围内呈线性关系,回归方程为:A=6.438×104C-2.184×104,r=0.9998。回收率为98.9%,RSD%为0.38(n=9)。结论本法可测定注射用羟喜树碱脂质体中羟喜树碱的含量,方法快速、简便、准确。     

白杨素衍生物的合成和晶体结构及与DNA的作用

以白杨素为先导化合物经羟甲基化反应合成中间体5,7-二羟基-6,8-二羟甲基黄酮(1)，进而合成了5,7-二羟基-6,8-二(甲氧基甲基)黄酮(2)，5,7-二羟基-6,8-二(乙氧基甲基)黄酮(3)，5,7-二羟基-6,8-二(丁氧基甲基)黄酮(4)，5,7-二羟基-6,8-二(戊氧基甲基)黄酮(5)和5-羟基-7-甲氧基-6,8-二(乙氧基甲基)黄酮(6)；采用IR，¹H NMR，¹³C NMR和元素分析对1～6进行了表征，同时用X-射线单晶衍射法对6进行了晶体结构测定。利用荧光法分别对1～4与CT-DNA的作用进行了研究，根据Stern-Volmer方程，它们对EB-DNA体系的荧光猝灭常数分别为k_q1=9.71×10³ L·mol^-1，k_q2=2.25×10⁴L·mol^-1，k_q3=1.03×10⁴L·mol^-1和k_q4=7.96×10³ L·mol^-1。1～4与白杨素相比，对DNA更具亲和力，为开发更有效的黄酮类化合物提供了实验依据。     

HPLC法测定妥布霉素滴眼液中5种抑菌剂

目的 建立同时测定妥布霉素滴眼液中5种抑菌剂(羟苯乙酯、硫柳汞、羟苯丙酯、苯扎溴铵和苯扎氯铵)的HPLC方法。方法 采用Agilent Zorbax SB-C₁₈ (4.6 mm×150 mm,5 μm)色谱柱,流动相A为1%三乙胺（磷酸调节pH值至3.5±0.05）;流动相B为甲醇,梯度洗脱,流速为1.0 mL·min^-1,柱温35 ℃,检测波长为214 nm。结果 羟苯乙酯、硫柳汞、羟苯丙酯、苯扎溴铵/苯扎氯铵各峰均分离良好;羟苯乙酯在0.77～192.5 μg·mL-1范围内线性关系良好(r=0.999 5),平均回收率为100.0%(RSD=0.9%,n=9);硫柳汞在2.16～541.0 μg·mL^-1范围内线性关系良好(r=0.999 7),平均回收率为100.1%(RSD=0.6%,n=9);羟苯丙酯在0.84～209.8 μg·mL^-1范围内线性关系良好(r=1.000 0),平均回收率为100.3%(RSD=1.0%,n=9);苯扎溴铵在4.36～1090 μg·mL^-1范围内线性关系良好(r=0.9992),平均回收率为100.2%(RSD=0.5%,n=9);苯扎氯铵（n-C12H25）3.22～805.0 μg·mL^-1范围内线性关系良好(r=0.999 8),平均回收率为100.1%(RSD=1.1%,n=9);苯扎氯铵（n-C14H29）1.66～413.9 μg·mL^-1范围内线性关系良好(r=1.000 0),平均回收率为100.1%(RSD=0.6%,n=9)。结论 该方法准确、灵敏、简便,可用于妥布霉素滴眼液中羟苯乙酯、硫柳汞、羟丙丙酯、苯扎溴铵及苯扎氯铵5种抑菌剂的检查。     

克拉霉素的极谱催化波及其应用

目的建立灵敏快速测定克拉霉素的新方法。方法基于氧化剂存在时克拉霉素产生的极谱催化波,用线性单扫描极谱法快速测定克拉霉素。结果在0.24 mol·L^-1 KH₂PO₄-Na₂HPO₄ (pH 6.81)支持电解质中，克拉霉素于-0.79 V (vs SCE)电位处产生1个还原波。加入过二硫酸钾后，该还原波峰电流增加约20倍，峰电位基本不变，产生一极谱催化波。其二阶导数峰电流i_p″与克拉霉素的浓度在4.0×10^-7-5.0×10^-5mol·L^-1呈良好线性关系(r=0.999 1,n=10)，检出限为2.0×10^-7 mol·L^-1。结论该方法可用于药剂中克拉霉素含量的测定。     

谷胱甘肽在10-甲基吩噻嗪修饰碳糊电极上的电催化氧化及电分析方法

研究了谷胱甘肽(还原型, glutathione, GSH)在10-甲基吩噻嗪(10-methylphenothiazine, MPT)修饰碳糊电极(MPT/CPE)上的电催化氧化行为。GSH在裸碳糊电极(carbon paste electrode， CPE)上的直接电化学氧化过程十分迟缓， 但在MPT/CPE上于0.702 V处出现一个不可逆氧化峰， 氧化电流大幅度增大。计时电流(chronoamperometry， CA)实验测得该电催化氧化反应速率常数k为(5.44±0.03)×10² (mol·L^-1)^-1·s^-1。用线性扫描伏安法(linear sweep voltammetry, LSV)测得催化氧化峰电流与GSH在5.0×10^-6～2.0×10^-3 mol·L^-1呈良好的线性关系， 线性回归方程I_pa=3.536c+2.117， r=0.999 0， 检测限为1.0×10^-6 mol·L^-1。同时用本方法对含GSH的市售药品进行了含量测定， 结果可靠。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.