强效镇痛剂研究 Ⅶ.1-β-羟基-3-甲基芬太尼(7302)及有关化合物非对映异构体的合成及镇痛活性

本文报道N-[1-(β-羟基-β-苯乙基)-3-甲基-4-哌啶基]-N-丙酰苯胺(简称1-β-羟基-3-甲基芬太尼,编号7302)及N-[1-苯甲酰基甲基-3-甲基-4-哌啶基]-N-丙酰苯胺(7303)非对映异构体的合成及镇痛活性。初步结果表明(小鼠,ip,热板法),7302分子中三个手性中心的构型对镇痛活性影响都至关重要。顺-A-7302的强度为顺-B-7302的5.3倍,反-A-7302为反-B-7302的2倍左右。顺-A-7302为四个非对映异构体中作用最强者,为吗啡的6000多倍,为依托芬的3倍左右。     

氚标记强效镇痛剂N-[1-(β-羟基-β-苯乙基)-3-甲基-4-哌啶基]-N-丙酰苯胺的制备以及与阿片受体的结合试验

本文报道以N-[1-(对-溴苯甲酰甲基)-3-甲基-4-哌啶基]-N-丙酰苯胺(Ⅲ)为前体,以PdO/BaSO_4作催化剂,用氚气进行卤—氚置换,氚化还原羰基的反应。反应产物经硅胶纸层析纯化后,用甲基橙比色法定量测定,得到N-{1-[β-羟基-β-氚-β-(对-氚苯基)乙基]-3-甲基-4-哌啶基}-N-丙酰苯胺(Ⅳ,[~3H]F-7302),其比放射性为59 Ci/mM,放化纯度为98％。[~3H]F-7302与小鼠脑内阿片受体的特异性结合在浓度为4.5×10~(-9)M时达到饱和,解离常数Kd=1.25×10~(-9)M,最大结合量B_(max)=93.08×10~(12)M/g蛋白,其特异性结合与非特异性结合比值达10～15。     

强效镇痛剂研究——Ⅴ.N-[1-(β-羟基-β-苯乙基)-3-甲基-4-哌啶基]-N-丙酰苯胺(7302)酯类衍生物的合成及镇痛活性

本文报道了一系列N-[1-(β-酰氧基-β-苯乙基)-3-甲基-4-哌啶基]-N-丙酰苯胺类衍生物及其化学结构与镇痛强度之间的关系,并测定了几个代表化合物的镇痛作用时间及与阿片受体亲和力。实验结果表明,7302的β-羟基酯化后,均能维持一定的镇痛强度,其镇痛作用时间与母体化合物7302相近。从受体结合试验来看,酯化后与受体亲和的能力显著下降。     

强效镇痛剂研究——Ⅱ.3-甲基芬太尼类衍生物的合成及镇痛活性

本文报道了N-[1-(β-苯乙基)-3-甲基-4-哌啶基]-N-丙酰苯胺(7209)和N-[1-(β-羟基-β-苯乙基)-3-甲基-4-哌啶基]-N-丙酰苯胺(7302)等一系列3-甲基芬太尼类衍生物的合成及镇痛活性。绝大部分该类衍生物均具有典型的吗啡样镇痛活性,是一类结构较简单、易于合成、镇痛作用极强的麻醉镇痛剂。化合物7302的ED₅₀为0.0022mg/kg(ip,小鼠,热板法),比芬太尼强28倍,竟达吗啡的6318倍,为我们至今合成该类衍生物中作用最强者。     

极谱法研究辅酶Q10与β-环糊精的包结行为

目的研究辅酶Q_{10与β-环糊精(β-CD)的包结行为。方法用极谱法考察主体分子β-CD与电活性客体分子辅酶Q10发生包结反应时，包结物还原波峰电流随时间的变化，峰电位随β-CD浓度的变化，并在自然光照条件下分别考察辅酶Q10和包结物的还原波峰电流随时间的变化。结果在0.1 mol·L^-1 HAc/NaAc (pH 4.7)的乙醇-水(60∶40)介质中，辅酶Q10与β-CD形成1∶1的包结物，测得其包结常数kf为1.26×10⁴ L·mol^-1，包结反应的表观速率常数k为6.64×10^-2 min^-1。并测得辅酶Q10的光降解表观速率常数k为7.77×10^-3 min^-1，辅酶Q10-β-CD包结物的k为3.38×10^-3 min^-1。结论辅酶Q10和β-CD可形成包结物，并在一定程度上提高了辅酶Q10的光稳定性。}     

7α和7β-甲基-10β,17β-二乙酰氧基-4-雌甾烯-3-酮的合成

由于7α-甲基或10β-乙酰氧基4(5)烯-3-酮雌(雄)甾化合物具有显著的抗着床或抗蜕膜活性,我们合成了既具有7α-甲基或7β-甲基又具有10β-乙酰氧基的两个新甾族化合物(1_a)和(1_b)。经药理试验表明(1_a)和(1_b)对孕鼠均有抗早孕作用。     

抗血吸虫病化合物:β-(5-硝基-2-呋喃)-丙烯酰二胺类衍生物的合成

本文报道70个β-(5-硝基-2-呋喃)-丙烯酰二胺类衍生物的合成。对感染日本血吸虫病小白鼠进行治疗和预防初筛的结果,发现有54个化合物具有不同程度的抗虫作用。其中以反式β-(5-硝基2-呋喃)-N-(2-哌啶乙基)丙烯酰胺盐酸盐(I₁₃,F-30385)及其盐基呋喃双胺(I₁₄,F-30642)杀虫作用最强,均已试用于临床,后者疗效较好,副作用较轻。     

7α-和7β-甲基-10β,17β-二乙酰氧基-△4-雌甾烯-3酮的抗早孕作用

7α-和7β-甲基-10β,17β-二乙酰氧基-△⁴-雌甾烯-3酮(简称7α-和7β-甲-乙氧雌酮)对小鼠抗早孕ED₅₀分别为1.6和5.5 mg/kg。7α-甲-乙氧雌酮在大鼠也有抗早孕作用并使血浆孕酮浓度降低,应用10 μg/ml浓度能抑制离体妊娠大鼠卵巢孕酮合成。7α-和7β-甲-乙氧雌酮与兔子宫胞浆雌二醇受体的相对结合亲和力(RBA)分别为10.8和1.5,与孕酮受体的RBA均<1.7α-和7β-甲-乙氧雌酮都有较弱的雌激素和抗雌激素活性。     

强效镇痛剂研究 Ⅶ.1-β-羟基-3-甲基芬太尼(7302)及有关化合物非对映异构体的合成及镇痛活性

本文报道N-[1-(β-羟基-β-苯乙基)-3-甲基-4-哌啶基]-N-丙酰苯胺(简称1-β-羟基-3-甲基芬太尼,编号7302)及N-[1-苯甲酰基甲基-3-甲基-4-哌啶基]-N-丙酰苯胺(7303)非对映异构体的合成及镇痛活性。初步结果表明(小鼠,ip,热板法),7302分子中三个手性中心的构型对镇痛活性影响都至关重要。顺-A-7302的强度为顺-B-7302的5.3倍,反-A-7302为反-B-7302的2倍左右。顺-A-7302为四个非对映异构体中作用最强者,为吗啡的6000多倍,为依托芬的3倍左右。     

拟人参皂苷F11在大鼠体内的药物代谢研究

目的探讨拟人参皂苷F11在大鼠体内的药物代谢产物及其过程.方法ip拟人参皂苷F₁₁后,应用TLC分析排泄物中的代谢产物,并利用制备薄层分离制备代谢产物,通过波谱解析(MS,¹HNMR,¹³CNMR,¹H-¹HCOSY)确定其结构.结果从粪便中分离鉴定了3种代谢产物,分别为拟人参皂苷R_T5,ocotillol和1个新的代谢产物F-3-1,并确定其结构为6-O-α-L-吡喃鼠李糖基(1-2)-β-D-吡喃葡糖基-(20S,23S,24R)-达玛-20(24)-环氧-3β,6α,12β,23,25-五醇(6-O-α-L-rhamnopyranosyl-(1-2)-β-D-glucopyranosyl-(20S,23S,24R)-dammar-20(24)-epoxy-3-β,6α,12β,23,25-pentanol).但在尿液和胆汁中并未发现任何代谢产物.结论拟人参皂苷F₁₁不被肝脏代谢,但胆汁排泄物可在肠道被代谢为水解和氧化产物.     

[3H] GR67330, a very high affinity ligand for 5-HT3 receptors

Summary GR67330 potently inhibited 5-hydroxytryptamine (5-HT)-induced depolarizations of the rat isolated vagus nerve. At the higher concentrations used (0.3 nmol/l–1 nmol/l) this was accompanied by a marked reduction in the maximum response to 5-HT. The calculated pK_B value was 10.2.The binding of the tritiated derivative of GR67330 to homogenates of rat entorhinal cortex was examined. Kinetic analysis revealed that specific [³H] GR67330 (0.1 nmol/l) binding was rapid and reversible. Association and dissociation rate constants were 1.48 ± 0.36 × 10⁸ mol/l^–1 s^–1 and 7.85 ± 0.41 × 10^–3 s^–1 respectively. Equilibrium saturation analysis revealed specific binding was to a single site (Bmax 22.6±0.21 fmol/mg protein) of high affinity (Kd 0.038±0.003 nmol/l). At low ligand concentrations, specific binding was up to 90% of total binding. If unlabelled GR67330 was used to define non-specific binding two sites were evident (Kd₁ 0.066 ± 0.007 nmol/l, Kd₂ 20.1 ± 9.7 nmol/l; Bmax₂ 31.5 ± 3.2 fmol/mg protein, Bmax₂ 1110 ± 420 fmol/mg protein). [³H] GR67330 binding was inhibited potently by 5-HT₃ antagonists and agonists. Ligands for other 5-HT receptors and other neurotransmitter receptors were either only weakly active or inactive at inhibiting binding. Hill numbers for antagonist inhibition of binding were close to unity, except for quipazine which was significantly greater than one. In common with other 5-HT₃ binding studies, all 5-HT₃ agonist tested had Hill numbers greater than one (1.51–1.71). GR38032 and GR65630 inhibited a greater proportion of binding than other 5-HT₃ antagonists, this additional binding was interpreted as inhibition from a second saturable site unrelated to the 5-HT₃ receptor.Homogenates of five areas of rat brain were examined for specific [³H]-GR67330 binding (entorhinal cortex, cingulate cortex, parietal cortex, hippocampus and nucleus accumbens/olfactory tubercle). In each brain area a site of very high affinity was labelled. Drug inhibition profiles were also very similar in each brain area. It is concluded that, because of its high affinity, [³H] GR67330 will be a useful ligand to label 5-HT₃ receptors especially in tissues with low receptor densities and to map 5-HT₃ receptors autoradiographically.Abbreviations 5-HT 5-Hydroxytryptamine - 8-OH-DPAT 8-hydroxy-2-di-N-propylaminotetralin - 5-CT 5-carboxyamidotryptamine - GR38032 (±) 1,2,3,9-tetrahydro-9-methyl-3[(2-methyl-1H-imidazol-1-yl)methyl]-4H-carbazol-4-one - GR65630 3-(5-methyl-1H-imidazol-4-yl)-1-(1-methyl-1H-indol-3-yl) -1-propanone - GR67330 (±)1,2,3,9 - tetrahydro-9-methyl-3-[(5-methyl-1H-imidazol-4-yl)methyl]-4H-carbazol-4-one - MDL72222 1H,3,5H-tropan-3-yl-3,5-dichlorobenzoate - ICS 205–930 (3-tropanyl)-1H-indole-3-carboxylic acid ester - BRL24924 endo-4-amino-5-chloro-2-methoxy-N-(1-azabicyclo[3,3,1]non-4-yl)benzamide - BRL43694 endo-N-(9-methyl-9-azabicyclo[3,3,1]non-3-yl)-1-methyl-indazole-3-carboxamide - SDZ 206-830 (3-homotropanyl)-1-methyl-5-fluoro-indole-3-carboxylic acid ester - mCPP meta-chlorophenylpiperazine Send offprint requests to G. J. Kilpatrick at the above address     

Synthesis of 2-(3-Substituted-1,2,4-oxadiazol-5-yl)-8-methyl-8-azabicyclo[3.2.1]octanes and 2α-(3-Substituted-1,2,4-oxadiazol-5-yl)-8-methyl-8-azabicyclo[3.2.1]oct-2-enes as Potential Muscarinic Agonists

Radioligand binding affinities of seven muscarinic receptor ligands which possess an oxadiazole ring side chain have been determined in rat heart, rat brain, and m₁- or m₃-transfected CHO cell membrane preparations to determine the selectivity for subtypes of muscarinic receptor. The ratios of binding constants in brain membranes were measured as an indicator of potential agonist activity against [³H]QNB and [³H]Oxo-M. These muscarinic ligands did not discriminate the subtypes of muscarinic receptors. Six muscarinic ligands which have a 3-amino- or 3-methyl-1,2,4-oxadiazol-5-yl groups attached to the 8-methyl-8-azabicyclo[3.2.1]oct-2-ene or 8-methyl-8-azabicyclo[3.2.1]octane head group show binding constants between 2.04 x 10^–6 and 1.79 x 10^–5 M in rat heart, rat brain, and m₁- or m₃-transfected CHO cell membrane preparations. 1-Methyl-2-[3-amino-1,2,4-oxadiazol-5-yl]piperidine shows low binding constants of approximately 10^–4 M in rat heart and rat brain. (1R,5S)-2-[3-Amino-1,2,4-oxadiazol-5-yl]-8-methyl-8-azabicyclo-[3.2.1]oct-2-ene [(1R,5S)-17] was the most active compound.     

Binding of [H]MSX-2 (3-(3-hydroxypropyl)-7-methyl-8-(m-methoxystyryl)-1-propargylxanthine) to rat striatal membranes — a new, selective antagonist radioligand for A2A adenosine receptors

The present study describes the preparation and binding properties of a new, potent, and selective A_2A adenosine receptor (AR) antagonist radioligand, [³H]3-(3-hydroxypropyl)-7-methyl-8-(m-methoxystyryl)-1-propargylxanthine ([³H]MSX-2). [³H]MSX-2 binding to rat striatal membranes was saturable and reversible. Saturation experiments showed that [³H]MSX-2 labeled a single class of binding sites with high affinity (K_d=8.0 nM) and limited capacity (B_max=1.16 fmol·mg⁻¹ of protein). The presence of 100 μM GTP, or 10 mM magnesium chloride, respectively, had no effect on [³H]MSX-2 binding. AR agonists competed with the binding of 1 nM [³H]MSX-2 with the following order of potency: 5′-N-ethylcarboxamidoadenosine (NECA)>2-[4-(carboxyethyl)phenylethylamino]-5′-N-ethylcarboxamidoadenosine (CGS-21680)>2-chloroadenosine (2-CADO)>N⁶-cyclopentyladenosine (CPA). AR antagonists showed the following order of potency: 8-(m-bromostyryl)-3,7-dimethyl-1-propargylxanthine (BS-DMPX)>1,3-dipropyl-8-cyclopentylxanthine (DPCPX)>(R)-5,6-dimethyl-7-(1-phenylethyl)-2-(4-pyridyl)-7H-pyrrolo[2,3-d]pyrimidine-4-amine (SH-128)>3,7-dimethyl-1-propargylxanthine (DMPX)>caffeine. The K_i values for antagonists were in accordance with data from binding studies with the agonist radioligand [³H]CGS21680, while agonist affinities were 3–7-fold lower. [³H]MSX-2 is a highly selective A_2A AR antagonist radioligand exhibiting a selectivity of at least two orders of magnitude versus all other AR subtypes. The new radioligand shows high specific radioactivity (85 Ci/mmol, 3150 GBq/mmol) and acceptable nonspecific binding at rat striatal membranes of 20–30%, at 1 nM.     

Influence of quinidine on the binding of [3H]-ouabain and [3H]-digoxin by human lymphocytes

Summary To explore the molecular basis of the glycoside-quinidine interaction, the in vitro effect of quinidine on the binding of [³H]-ouabain and [³H]-digoxin to Na⁺ K⁺ ATPase receptors on human mononuclear cells was investigated. The maximum [³H]-ouabain binding capacity was 45.7±9.4×10³ molecules/cell in pure lymphocyte preparations (n=8) and 75.5±7.3×10³ molecules/cell in mixtures of mononuclear cells (n=8). These parameters were not influenced by 10⁻⁵ M quinidine. In eight equilibrium experiments with pure lymphocytes, the dissociation constant of [³H]-ouabain increased from 0.79±0.26×10⁻⁸ M in the absence of 10⁻⁵ M quinidine to 1.56±0.74×10⁻⁸ M in its presence (p<0.01), indicating that the affinity of the drug was decreased. Similar findings were observed using mixed mononuclear cells. In five uptake and release experiments, quinidine decreased the association rate constant of [³H]-ouabain from 3.15±0.36×10⁴ M⁻¹×s⁻¹ to 2.01±0.37×10⁴ M⁻¹ s⁻¹ (p<0.01), whereas the dissociation rate constant was not affected. A therapeutic concentration of quinidine does not affect the number of glycoside receptors on lymphocytes, but it does appear to reduce fractional receptor occupancy by both [³H]-ouabain and [³H]-digoxin at lower tracer concentrations. This finding is compatible with the clinical observation that quinidine reduces the distribution volume of digoxin.     

Synthesis of high specific activity (3,4-[3H]cyclohexyl)-N-[1 (2-benzo[b]thienyl)cyclohexyl]piperidine {[3H]BTCP}: A selective probe for the dopamine-reuptake complex

High specific activity [³H]BTCP, a radioligand for the dopaminereuptake complex was synthesized in 7-steps starting with the readily available starting materials, cyclohexane-1,4-dione monoethylene ketal and benzo[b]thiophene; the tritium label was introduced in the final step on the 3- and 4- positions of the cyclohexyl ring by catalytic tritiation of N-[4-(2-benzo[b]thienyl)cyclohexenyl]piperidine to give [³H]BTCP in 7.3% yield with a specific activity of 29.8 Ci/mmol (51.4% isotopic incorporation).     

甲基黄酮醇胺盐酸盐对β受体的阻断作用

The β-receptor blocking action of methylflavonolamine hydrochloride(MFA) was studied and compared with those of propranolol. The doseresponse curves of isoproterenol were shifted to the right by MFA on isolated rabbit atrium in this experiment. The pA₂ value and the slope of the regression line of MFA calculated from Schild plot were 5.53 and -0.84 respectively. The effects of MFA and propranolol on duck erythrocyte membranes were studied by the radioligand binding method. Both MFA and propranolol inhibited the binding of [³H] dihydroalprenolol to β-receptors. Their apparent equilibrium dissociation constants were 1.12×10^-5 mol/L and 5.50×10^-9 mol/L respectively. The affinity of propranolol to β-receptors of duck erythrocyte membranes was 2039-fold higher than that of MFA. These results demonstrates that MFA is a weak competitive β-receptor blocking agent.