黄芪中5种黄酮类成分的含量测定及其指纹图谱研究

目的 建立同时测定黄芪中5种黄酮类成分含量的高效液相色谱（HPLC）分析方法并进行黄芪的指纹图谱研究。方法 采用HPLC-DAD,Waters SymmetryShield^TM RP₁₈色谱柱（250 mm×4.6 mm,5 μm）,乙腈（A）-水（0.05%磷酸）（B）为流动相梯度洗脱,体积流量1.0 mL/min,检测波长246、206 nm,柱温25℃,进样量20 μL,对黄芪中毛蕊异黄酮葡萄糖苷、芒柄花苷、（6aR,11aR）-9,10-二甲氧基紫檀烷-3-O-β-D-葡萄糖苷、毛蕊异黄酮、7-羟基-4''-甲氧基异黄酮进行含量测定。结果 方法学考察结果显示,黄芪中5种黄酮类成分线性范围,相关系数良好（r=0.999 8~0.999 9,n=9）,各色谱峰间分离度均达到定量要求。精密度（RSD<1.86%）,稳定性（RSD<2.01%）,重复性（RSD<1.97%）,加样回收率（RSD<2.90%,n=9）等参数均达到定量分析要求。建立了黄芪的HPLC指纹图谱,标定了27个共有峰,样品相似度在0.808~0.971,存在一定差异。结论 本实验建立的方法准确、简便、重复性好,可为黄芪药材的质量控制提供参考。     

硫磺熏蒸对黄芪中黄酮类和皂苷类成分的影响

目的测定硫磺熏前后黄芪中黄酮类和皂苷类成分的变化,确定硫磺熏对黄芪药材质量的影响,为评价熏硫加工对黄芪质量的影响提供依据。方法对收集的黄芪进行熏硫加工,采用HPLC-DAD法测定了毛蕊异黄酮苷、芒柄花苷、毛蕊异黄酮、芒柄花素4种黄酮成分,UPLC-ELSD法测定了黄芪皂苷I、黄芪皂苷II、黄芪皂苷III、黄芪甲苷4种皂苷成分。结果硫磺熏过的黄芪药材中毛蕊异黄酮苷、芒柄花苷含量降低,毛蕊异黄酮、芒柄花素、黄芪皂苷I、黄芪皂苷III、黄芪甲苷的含量变化不明显。结论黄芪熏硫加工后,黄酮苷成分有所降低,其余成分变化不明显。     

HPLC法测定参乌益肾片中8种成分及其化学计量学综合评价

目的 建立HPLC法同时测定参乌益肾片中β-蜕皮甾酮、25R-牛膝甾酮、25S-牛膝甾酮、大车前苷、毛蕊花糖苷、异毛蕊花糖苷、木通苯乙醇苷B和2,3,5,4′-四羟基二苯乙烯-2-O-β-D-葡萄糖苷8种成分,联合化学计量学方法对参乌益肾片的产品质量进行综合评价。方法 采用Sepax Bio-C₁₈色谱柱（250 mm×4.6 mm,5 μm）;以乙腈–0.1%甲酸进行梯度洗脱;检测波长分别为250 nm（0～20 min测定β-蜕皮甾酮、25R-牛膝甾酮和25S-牛膝甾酮）、330 nm（20～60 min测定大车前苷、毛蕊花糖苷、异毛蕊花糖苷、木通苯乙醇苷B和2,3,5,4′-四羟基二苯乙烯-2-O-β-D-葡萄糖苷）;柱温30℃;体积流量1.0 mL/min;进样量10 μL。采用聚类分析、主成分分析和偏最小二乘法–判别分析法对8种指标成分检测结果相关性进行分析评价。结果 β-蜕皮甾酮、25R-牛膝甾酮、25S-牛膝甾酮、大车前苷、毛蕊花糖苷、异毛蕊花糖苷、木通苯乙醇苷B和2,3,5,4′-四羟基二苯乙烯-2-O-β-D-葡萄糖苷分别在1.47～36.75、0.66～16.50、0.74～18.50、5.80～145.00、15.77～394.25、4.58～114.50、1.29～32.25、8.78～219.50 μg/mL有良好的线性关系;平均回收率分别为97.78%、96.90%、97.96%、99.67%、100.01%、99.54%、98.03%、100.11%,RSD值分别为1.17%、0.82%、1.48%、0.93%、0.77%、0.69%、1.13%、0.65%。成分8（2,3,5,4′-四羟基二苯乙烯-2-O-β-D-葡萄糖苷VIP＝1.503）、成分4（大车前苷AVIP＝1.404）、成分5（毛蕊花糖苷VIP＝1.274）、成分1（β-蜕皮甾酮VIP＝1.030）是影响参乌益肾片样品质量的关键成分。结论 建立的方法简便快捷、准确可靠,可用于参乌益肾片中多指标成分的质量综合评价模式。     

黄芪饮片中4个异黄酮类成分的含量测定

摘 要 目的:建立高效液相色谱法测定黄芪饮片中4个异黄酮成分的含量方法。方法: 色谱柱为Agilent Zorbax SB-C₁₈(250 mm×4.6 mm,5 μm) ,流动相为乙腈-水梯度洗脱,流速1.0 ml·min^-1,检测波长为260 nm, 柱温30℃,进样量10 μl。结果:毛蕊异黄酮-7-葡萄糖苷、芒柄花苷、毛蕊异黄酮、芒柄花素分别在4.42～442 μg·ml^-1、2.06～206 μg·ml^-1、3.36～336 μg·ml^-1、4.60～460 μg·ml^-1浓度范围内与各自峰面积积分值呈良好的线性关系;平均回收率分别为99.4%(RSD=5.34%)、94.8%(RSD=2.39%)、98.9%(RSD=3.69%)、102.3%(RSD=3.01%)(n=9)。结论:本方法简便、准确、重复性好,可用于黄芪饮片的质量控制。     

含量测定结合HPLC指纹图谱优选黄芪不同栽培方式

目的 优选黄芪药材的最佳栽培方式。方法 采用高效液相色谱（HPLC）指纹图谱技术,以4个成分（毛蕊异黄酮葡萄糖苷、芒柄花苷、毛蕊异黄酮、芒柄花素）的含量及黄芪黄酮的高效液相色谱特征图谱的共有峰总面积之和为综合评判指标,通过考察不同栽培方式（不起垄覆膜、10cm垄高覆膜、20cm垄高覆膜、30cm垄高覆膜、露头移栽）对黄芪药材质量的影响。结果 当栽培方式为不起垄覆膜（即当地传统的平地开沟覆膜移栽）时,黄芪药材质量最优。结论 该试验考察了不同栽培方式对于黄芪药材质量的影响,为以后黄芪药材进一步的种植研究提供依据。     

HPLC法同时测定黄芪中4种黄酮类成分的含量

目的:建立以高效液相色谱法同时测定11个产地黄芪中毛蕊异黄酮葡萄糖苷、芒柄花苷、毛蕊异黄酮和芒柄花素4种黄酮类成分含量的方法,从有效成分含量探讨药材道地性内在因素。方法:色谱柱为Zorbax Eclipse XDB-C1(8250mm×4.6mm,5μm),流动相为乙腈-0.2%甲酸水溶液(梯度洗脱),检测波长为280nm。结果:毛蕊异黄酮葡萄糖苷、芒柄花苷、毛蕊异黄酮和芒柄花素的检测浓度分别在0.0051～0.510、0.0050～0.300、0.0049～0.294、0.0046～0.276mg·mL-1范围内与各自峰面积积分值呈良好的线性关系(r均为0.9999)。内蒙古、山西等4个产地的黄芪中毛蕊异黄酮苷和芒柄花苷的含量较高;河北安国、赤城和甘肃定西产黄芪中毛蕊异黄酮和芒柄花素含量较高。结论:本方法简便、快速、准确,试验结果与黄芪本草考证、道地沿革的文献基本相符。     

一测多评法同时测定炙黄芪中4种黄酮类成分

目的: 利用一测多评法（QAMS）同时测定炙黄芪配方颗粒中毛蕊异黄酮葡萄糖苷、芒柄花苷、毛蕊异黄酮及芒柄花素4种黄酮类成分,为炙黄芪配方颗粒的质量评价分析提供科学依据。方法: 炙黄芪配方颗粒经70%甲醇超声提取后,利用Agilent Eclipse XDB-C18色谱柱（4.6 mm×250 mm,5 μm）,以乙腈-0.2%甲酸水溶液为流动相进行梯度洗脱,流速为1.0 mL·min-1,柱温为30℃,检测波长为250 nm。以毛蕊异黄酮葡萄糖苷为内参物,建立其与芒柄花苷、毛蕊异黄酮、芒柄花素的相对校正因子。分析比较外标法（ESM）和一测多评法（QAMS）同时测定其4种成分的含量差异。结果：在一定线性范围内,毛蕊异黄酮葡萄糖苷相对毛蕊异黄酮、芒柄花苷、芒柄花素的相对校正因子耐用性良好,外标法（ESM）和一测多评法（QAMS）所测含量无明显差异。结论: 建立的一测多评法（QAMS）测定炙黄芪配方颗粒中4种成分含量的方法,快捷、简便、准确度高、重复性好,可为其质量标准研究及评价分析提供依据。     

HPLC-QAMS同时测定芪桑益肝丸中8种成分的含量

目的 建立高效液相一测多评法（HPLC-QAMS）同时测定芪桑益肝丸中虎杖苷、白藜芦醇、大黄素、獐牙菜苦苷、龙胆苦苷、獐牙菜苷、毛蕊异黄酮葡萄糖苷和芒柄花素的含量。方法 采用Agilent HC-C₁₈色谱柱（250 mm×4.6 mm，5 μm），柱温30℃；乙腈-0.1%甲酸水溶液为流动相梯度洗脱，流速1.0 mL·min^-1；检测波长分别为290 nm （检测虎杖苷、白藜芦醇和大黄素）、243 nm （检测獐牙菜苦苷、龙胆苦苷、獐牙菜苷）和254 nm （检测毛蕊异黄酮葡萄糖苷、芒柄花素）。以獐牙菜苦苷为内参物，建立其他7个成分的相对校正因子，计算含量。结果 虎杖苷、白藜芦醇、大黄素、獐牙菜苦苷、龙胆苦苷、獐牙菜苷、毛蕊异黄酮葡萄糖苷和芒柄花素质量浓度分别在3.46~69.20，2.09~41.80，2.77~55.40，6.71~134.20，2.88~57.60，1.19~23.80，0.56~11.20，0.89~17.80 μg·mL^-1内线性关系良好（r≥0.999 1），平均加样回收率（RSD）分别为100.05%（0.82%），97.79%（1.07%），98.41%（0.99%），99.75%（0.65%），98.72%（1.21%），99.07%（1.19%），96.99%（1.04%），97.65%（1.38%），一测多评法计算结果与外标法实测值无显著性差异。结论 所建立的HPLC-QAMS方法专属性强、准确度高，为芪桑益肝丸的质量评价提供了参考依据。     

膜荚黄芪毛状根中异黄酮成分的反相高效液相色谱分析

对膜荚黄芪毛状根中6种异黄酮成分进行了反相高效液相色谱法测定。色谱柱为NucleosilC₁₈柱,流动相为甲醇—水(3∶2和3∶1,v/v),检测波长为254nm和280nm。6种异黄酮成分为:10-羟基-3,9-二甲氧基紫檀烷,(3R)8,2’-二羟基-7,4’-二甲氧基异黄烷,芒柄花素(7-羟基-4’-甲氧基异黄酮),8,3’-二羟基-7,4’-二甲氧基异黄酮,2’-羟基-3’,4’-二甲氧基异黄烷-7-O-葡萄吡喃糖甙,毛蕊异黄酮(7,3’-二羟基-4’-甲氧基异黄酮)。异黄酮浓度在2.5～12.5μg范围内与峰面积有良好的线性关系;加样回收率为96.47%～103.33%;精密度试验相对标准偏差为2.57%～6.52%;测得黄芪毛状根中6种异黄酮成分的含量在0.0005%～0.0065%之间。     

HPLC波长切换法同时测定心神安胶囊中9种成分的含量

目的 建立HPLC波长切换法同时测定心神安胶囊中9种成分的含量。方法 采用Agilent Eclipse XDB-C₁₈色谱柱,流动相乙腈（A）-0.1%甲酸溶液（B）,梯度洗脱;流速0.9 mL·min^-1;检测波长分别为320 nm[检测远志（口山）酮Ⅲ、3,6''-二芥子酰基蔗糖]、203 nm （检测人参皂苷Rb₁、绞股蓝皂苷XLIX、绞股蓝皂苷XVⅡ）和254 nm （检测毛蕊异黄酮葡萄糖苷、芒柄花苷、毛蕊异黄酮、芒柄花素）;柱温25℃。结果 远志（口山）酮Ⅲ、3,6''-二芥子酰基蔗糖、人参皂苷Rb₁、绞股蓝皂苷XLIX、绞股蓝皂苷XVⅡ、毛蕊异黄酮葡萄糖苷、芒柄花苷、毛蕊异黄酮、芒柄花素分别在2.070~41.40 μg·mL^-1（r=0.999 2）、3.860~77.20 μg·mL^-1（r=0.999 6）、11.29~225.8 μg·mL^-1（r=0.999 8）、5.070~101.4 μg·mL^-1（r=0.999 9）、19.86~397.2 μg·mL^-1（r=0.999 5）、1.280~25.60 μg·mL^-1（r=0.999 1）、0.960 0~19.20 μg·mL^-1（r=0.999 3）、0.670 0~13.40 μg·mL^-1（r=0.999 7）、2.580~51.60 μg·mL^-1（r=0.999 1）内线性关系良好,平均回收率分别为98.04%,99.26%,99.05%,97.42%,100.0%,98.27%,97.81%,96.84%和99.86%,RSD分别为1.28%,0.82%,1.43%,1.43%,0.86%,1.26%,1.38%,1.16%和0.69%。结论 本方法操作简便、准确、重复性好,能够对心神安胶囊中9种成分进行同时含量测定,为提高和完善心神安胶囊的质量标准提供了有效方法。     

Synthesis and evaluation of 2,6-piperidinedione derivatives as potentially novel compounds with analgesic and other CNS activities

New 2,6-piperidinediones 2_a–g and 4_a–d were prepared by initial condensation of aromatic aldehydes or cycloalkanones with cyanoacetamide to give α-cyanocinnamides l_a–g or cycloalkylidenes 3_a,b which underwent Michae1 addition with ethyl cyanoacetate or diethylmalonate. Compounds 4_a–d were alkylated by various alkyl halides to produce the N-alkylated 2,6-piperidinedione derivatives 5_a–m. Some new selected compounds 2_a–c,f, 4_a–d & 5_e,h,j were pharmacologically evaluated for potential anticonvulsant, sedative and analgesic activities. These compounds exhibited significant anticonvulsant and analgesic effects after a single I.P. administration 100 mg/kg b.wt. . On the other hand all the investigated compounds induced hypnotic activity and prolonged the phenobarbital sodium- induced sleep as compared with the control group and the most potent compound was found to be 2_f.     

EFFECT OF POLICOSANOL SUCCESSIVE DOSE INCREASES ON PLATELET AGGREGATION IN HEALTHY VOLUNTEERS

Policosanol is a cholesterol-lowering drug with hypocholesterolemic effects demonstrated in experimental models, healthy volunteers and type II hypercholesterolemic patients. In addition, antiplatelet effects of policosanol have been shown in experimental models and healthy volunteers. The effect of successively increasing doses of policosanol on platelet aggregation was investigated in a randomized, placebo-controlled, double-blind study conducted in 37 healthy volunteers. The volunteers were on a placebo-baseline period (two tablets per day) for 7 days and thereafter they received randomly, under double-blind conditions, placebo or policosanol (10mgday⁻¹) for 7 days. After this period dosage was doubled to 20mgday⁻¹for the next 7 days and then again doubled to 40mgday⁻¹, while the control group received placebo tablets all the time. Platelet aggregation as well as coagulation time was measured at baseline and after each dosing step. Results showed that antiplatelet effects of policosanol were successfully enhanced throughout the study, thus suggesting a dose-dependent relationship. No significant effect was reached during the first dosing period, but significant reductions of epinephrine and ADP-induced platelet aggregation were observed after the second one. Finally, a significant inhibition of platelet aggregation induced by all the agonists was observed at the last dosing step. Coagulation time remained unchanged during the trial.     

鼻渊净胶囊的HPLC指纹图谱研究

目的 建立鼻渊净胶囊的高效液相色谱(HPLC)指纹图谱.方法 采用Agilent SB-C18(4.6 mm×250 mm,5μm)色谱柱,乙腈-水为流动相、以1.0 ml/min流速行梯度洗脱,检测波长210 nm,柱温30℃,洗脱时间为80 min.采用中药色谱指纹图谱相似度评价系统(2004A版)对检测出色谱进行...     

NEURAMIDE STIMULATES ADRENOCORTICOTROPIN BUT NOT PROLACTIN RELEASE FROM RAT PITUITARY

Neuramide (NMD), a substance found in crude preparations of porcine stomach extract, is a viral inhibitor that also has putative immunostimulatory effects. The effects of NMD on stress-hormone (ACTH and prolactin—PRL) release were assessed inin vivoandin vitrostudies. In the former, blood levels of corticosterone and PRL were measured in NMD-treated male rats.In vitroexperiments were performed to evaluate the effects of NMD and three of its fractions (obtained with high performance liquid chromatography) on ACTH and PRL release from perfused rat pituitary slices. NMD increased plasma corticosterone levelsin vivoand produced dose-dependent increases inin vitropituitary release of ACTH. No effects on PRL secretion were observedin vivoorin vitro. The stimulatory effects on ACTH release were caused by the NMD fraction with a molecular weight of >5000<10000Da.     

Investigation of the prevalence of tetQ, tetX and tetX1 genes in Bacteroides strains with elevated tigecycline minimum inhibitory concentrations

In this study, the antibiotic susceptibilities to tigecycline and tetracycline of 35 selected Bacteroides fragilis group strains were determined by Etest, and the presence of tetQ, tetX, tetX1 and ermF genes was investigated by polymerase chain reaction (PCR). tetQ was detected in all 12 B. fragilis group isolates (100%) exhibiting elevated tigecycline minimum inhibitory concentrations (MICs) (≥8 μg/mL) as well as the 8 strains (100%) with a tigecycline MIC of 4 μg/mL, whilst tetX and tetX1 were present in 15% and 75% of these strains, respectively. All of these strains were fully resistant to tetracycline (MIC ≥ 16 μg/mL). On the other hand, amongst the group of strains with tigecycline MICs < 4 μg/mL (15 isolates), tetQ, tetX and tetX1 were found less frequently (73.3%, 13.3% and 46.7%, respectively). All but two strains harbouring the tetQ gene in this group were non-susceptible to tetracycline, with a MIC > 4 μg/mL. These data suggest that in most cases tigecycline overcomes the tetracycline resistance mechanisms frequently observed in Bacteroides strains. However, the presence of tetX and tetX1 genes in some of the strains exhibiting elevated MICs for tigecycline draws attention to the possible development and spread of resistance to this antibiotic agent amongst Bacteroides strains. The common occurrence of ermF, tetX, tetX1 and tetQ genes together predicted the presence of the CTnDOT-like Bacteroides conjugative transposon in this collection of Bacteroides strains.     

INDIRECT PARASYMPATHOMIMETIC ACTIVITY OF THE CLASS III ANTIARRHYTHMIC SUBSTANCE / -SOTALOLIN VITRO: REVERSIBLE INHIBITION OF CHOLINESTERASE ISOENZYMES FROM BLOOD AND THE HUMAN CENTRAL NERVOUS SYSTEM

Inhibitory effects of the class III antiarrhythmic compound / -sotalol on acetylcholinesterase (AChE; EC 3.1.1.7) isoenzymes of both erythrocytes and the human caudate nucleus and on serum cholinesterase (ChE; EC 3.1.1.8) were studiedin vitrousing a spectrophotometric kinetic assay with acetylthiocholine (ASCh) as substrate. Sotalol concentrations in the assays varied from 0.32 to 3.2m . All isoenzymes studied were inhibited by / -sotalol in a reversible and concentration-dependent manner. Double reciprocal plots of the reaction velocity against varying ASCh concentrations revealed that / -sotalol reduced substrate affinity (apparent Michaelis constant, KM, increased) of serum ChE, but did not change the enzyme's maximal rate of ASCh hydrolysis (V_max). Thus, / -sotalol inhibition of serum ChE was of the competitive type (rate constant for reversible competitive inhibition: K_i=0.51m ). In contrast, / sotalol reduced the maximal reaction velocity of the AChE isoenzyme from the central nervous system (caudate nucleus), but had no influence on substrate affinity of the enzyme (K_Mwith ASCh unchanged) indicating purely non-competitive inhibition kinetics (rate constant of reversible non-competitive inhibition: K_i′=0.44m ). / -sotalol inhibition of erythrocyte AChE was of mixed competitive/non-competitive type (K_i=0.31m , K_i′=0.49m ). Non-competitive / -sotalol inhibition of caudate nucleus AChE and the non-competitive component of erythrocyte AChE inhibition cannot be overcome by increased concentrations of the cholinergic transmitter acetylcholine (ACh). Peak / -sotalol plasma levels as described in the literature for both humans (15μ ) and experimental animals (dogs: 18μ ; rats: 260μ ) as well as maximal myocardial concentrations of the substance (dogs: 46μ ; rats: 478μ ) are in the range of about 2% to 100% of the sotalol inhibition rate constants determined in the present paper for cholinesterase isoenzymesin vitro. Thus, / -sotalol inhibition of ACh hydrolysisin vivomay contribute to both the well known antiarrhythmic potential and proarrhythmic side effects of the compound.     

AMELIORIATION OF CHEMICALLY-INDUCED HEPATOCYTE INJURY BY CYCLOSPORINE A

Cyclosporine A, beside its current applications, possesses potential hepatoprotective effects. This study was directed to investigate the effect of Cyclosporine A pretreatment on hepatic injury due to carbon tetrachloride (CCl₄) and -galactosamine. Rats were injected by two successive doses of Cyclosporine A (5mgkg⁻¹day⁻¹). Six hours after the second dose, 1mlkg⁻¹of CCl₄was administered i.p. Effects associated with Cyclosporine A pretreatment were examined by using isolated hepatocytes and hepatocytes that were immobilized and continuously perfused. -Galactosamine (5m ) was added directly to the perfusion medium. After isolation, hepatocytes were examined histologically by light and electron microscopy, immobilized and perfused for further metabolic functional activity evaluation. Cyclosporine A pretreatmentin vivoproduced hepatoameliorative effects of various degrees which were statistically significant as manifested by: (1) an increased trypan blue exclusion after CCl₄; (2) an improved ureagenesis after CCl₄; (3) a reduction in the lipid droplets accumulation in the cytoplasm produced by CCl₄administration; (4) well preserved cytoplasmic organelles as mitochondria, endoplasmic reticulum ER, nuclear chromatin structures that were altered by CCl₄; and (5) an increased hepatocytes survival in the agarose gel matrix, reduction of LD leakage and improvement of ureagenesis after -galactosamine addition to the perfusion medium. The beneficial effect of Cyclosporine A pretreatment in modifying hepatotoxicity of chemical insults merits further studies.     

栝楼不同药用部位质量控制的研究进展

瓜蒌子、瓜蒌皮、瓜蒌、天花粉来源于栝楼的不同药用部位,4味药材均为常用的大宗药材,现行版《中国药典》对其制定的质量标准过于简单,无法科学合理地控制其质量。本文对瓜蒌子、瓜蒌皮、瓜蒌、天花粉安全性和有效组分的研究进行综述,明确了相关研究存在的问题并针对问题提出建议,为科学全面的药材及饮片标准的制定提供参考依据。     

喙果黑面神化学成分研究

目的研究大戟科植物喙果黑面神(Breynia rostrata Merr.)的化学成分。方法利用硅胶、凝胶等色谱技术分离纯化化学成分,根据化合物的理化性质和光谱数据进行结构鉴定。结果从喙果黑面神的正丁醇萃取部分分离得到4个化合物,分别鉴定为6-O-甲基丙酰基-α-D-吡喃葡糖(6-O-methylpropanoyl-α-D-glucopyranose,1);4″-苯酚基-6-O-甲基丙酰基-β-D-吡喃葡糖苷(4″-phenolic-6-O-methylpropanoyl-β-D-glucopyranoside,2);1-O-没食子酰基-β-D-吡喃葡糖苷(1-O-galloyl-β-D-glucopyranoside,3);熊果苷(arbutin,4)。结论化合物1和2为新化合物,3和4均为首次从该种植物分离得到。     

EFFECTS OF 2-GUANIDINE-4-METHYLQUINAZOLINE ON GASTRIC ACID SECRETION IN RATS

In this study 2-guanidine-4-methylquinazoline (2-GMQ) appeared to decrease basal and stimulated gastric acid secretion, while structurally related compounds as dimethyl- biguanide, cyanoguanidine and 2-cyanoamino-4-methylpyrymidine did not. Thus, there is an antisecretory effect when the biguanide group is associated with a lipophilic structure. The antisecretive effects exerted by 2-GMQ are associated with anti H₂-histamine activity.The anti H₂-histamine nature of the effects of 2-GMQ was confirmed by the capacity of this compound of depressing the chronotropic activity of the isolated guinea pig auricle increased by histamine, as well as relaxant activity in rat uterus contracted by histamine, since both preparations are rich in H₂-histamine receptors.