木香提取物中木香烃内酯和去氢木香内酯的平衡溶解度和油水分配系数的测定

目的 测定木香提取物中木香烃内酯和去氢木香内酯的平衡溶解度及表观油水分配系数,为木香提取物新剂型研究提供实验依据。方法 分别采用饱和溶液法和摇瓶法,使用高效液相色谱（HPLC）法测定木香烃内酯和去氢木香内酯的浓度,以计算木香乙醇提取物中木香烃内酯和去氢木香内酯在不同体积分数乙醇、丙二醇、甘油、聚乙二醇（PEG）、不同pH值磷酸盐缓冲液（PBS）中的平衡溶解度和在正辛醇-不同pH值PBS液中油水分配系数。结果 37℃时,木香烃内酯和去氢木香内酯在水中的平溶解度分别为17.31、24.32 μg/mL;木香烃内酯和去氢木香内酯在乙醇、PEG、甘油、1,2-丙二醇的水溶液中平衡溶解度随着溶剂添加比例（5%、10%、20%）的增加而增加,在20%乙醇中溶解度最大,分别为108.81、125.61 μg/mL,在5%甘油中溶解度最小,分别为31.72、42.83 μg/mL。两者在pH 7.4和pH 9.0的磷酸盐缓冲液中平衡溶解度分别达到最大,分别为16.63、26.14 μg/mL。两种成分在pH7.4的磷酸盐缓冲溶液中油水分配系数均达到最大,分别为89（logP_app=1.95）、144.30（logP_app=2.16）。结论 木香烃内酯和去氢木香内酯水溶性差,pH值影响两者的平衡溶解度和表观油水分配系数。     

常绿钩吻碱平衡溶解度、油水分配系数及解离常数的测定

目的 测定常绿钩吻碱(Sempervirine,SPV)在不同pH磷酸盐缓冲液（PBS）中的平衡溶解度和油水分配系数,考察常绿钩吻碱的解离常数,为常绿钩吻碱的剂型开发提供一定的依据。方法 采用超高效液相色谱法（UPLC）结合摇瓶法测定常绿钩吻碱在不同pH的PBS中的平衡溶解度和正辛醇-PBS中的油水分配系数;采用紫外分光光度法测定常绿钩吻碱的解离常数。结果 常绿钩吻碱在pH 1.2~7.4的PBS中的溶解度为285.356~557.945 mg?L^-1,油水分配系数在0.316~5.803,解离常数pKa为11.10。结论 pH值影响常绿钩吻碱平衡溶解度和油水分配系数,常绿钩吻碱的低溶解度与解离常数可能影响其体内吸收。     

盐酸奈必洛尔平衡溶解度及表观油水分配系数的测定

摘 要 目的：测定盐酸奈必洛尔的平衡溶解度和表观油水分配系数,为药物新剂型的研究与开发提供试验基础。方法: 采用高效液相色谱法测定盐酸奈必洛尔溶液的含量,运用饱和溶液法测定盐酸奈必洛尔在纯水、0.1 mol·L^-1 盐酸溶液及不同pH磷酸盐缓冲液（pH2.0,pH6.8,pH7.4,pH8.0）中的平衡溶解度;通过摇瓶法测定其在正辛醇 水/缓冲液体系中的表观油水分配系数。结果: （37±0.5）℃下,盐酸奈必洛尔在纯水和0.1 mol·L^-1 盐酸的平衡溶解度分别为722.53 μg·mL^-1和56.07 μg﹒mL^-1,在正辛醇 水/盐酸体系中表观油水分配系数(Log P)分别为1.17和1.32。在pH2.0～7.4的磷酸盐缓冲液中,盐酸奈必洛尔的平衡溶解度和表观油水分配系数随pH升高,分别呈现出降低和增加的趋势;而当pH从7.4增加至8.0时,平衡溶解度增加,表观油水分配系数降低。结论:本文建立的含量测定方法简单可靠,盐酸奈必洛尔水溶性差,其平衡溶解度和表观油水分配系数呈现出pH依赖性。     

星点设计-效应面法优化镰形棘豆总黄酮的提取工艺

摘 要 目的：优选镰形棘豆总黄酮的提取工艺。方法: 以总黄酮含量为指标,在单因素试验的基础上,采用星点设计 效应面法考察溶剂用量、乙醇体积分数、提取时间对镰形棘豆总黄酮含量的影响。结果: 最佳提取工艺为加入20倍量66%乙醇回流提取2次,每次84 min,在此条件下,总黄酮的含量达23.21 mg·g^-1。结论:采用星点设计 效应面法优选的提取工艺条件稳定可行,预测性好。     

双氯芬酸钠平衡溶解度和表观油水分配系数的研究

目的 测定双氯芬酸钠平衡溶解度及表观油水分配系数,为药物评价、新剂型设计与开发提供试验依据。方法 采用反相高效液相色谱法（RP-HPLC）测定双氯芬酸钠在不同介质中的平衡溶解度,使用Diamonsil C₁₈（150 mm×4.6 mm,5 μm）色谱柱,甲醇-水-磷酸（80∶19∶1）为流动相,体积流量为0.8 mL/min,检测波长为276 nm,柱温为32 ℃;采用摇瓶法测定双氯芬酸钠在正辛醇-水/缓冲液体系中的表观油水分配系数。结果 32 ℃时,双氯芬酸钠在蒸馏水和生理盐水中的平衡溶解度分别为18.2、5.52 mg/mL;在肉豆蔻酸异丙酯（IPM）、油酸乙酯中的平衡溶解度分别为0.637、1.97 mg/mL;在正辛醇/水体系中的表观油水分配系数为1.41（lgP＝0.15）;在pH 5.0～7.4缓冲液中,其平衡溶解度随pH值升高而增大,表观油水分配系数随pH值升高而降低;结论 pH对双氯芬酸钠的平衡溶解度和表观油水分配系数有较大影响。     

镰形棘豆总黄酮的含量测定方法研究

目的 建立紫外-可见分光光度法测定镰形棘豆总黄酮含量的方法。方法 分别采用直接测定法、氯化铝-醋酸钠显色法和硝酸铝显色法,以芦丁为对照品,探究最优显色方法并进行显色条件优化和系统的方法学考察。结果 最优显色法为氯化铝-醋酸钠显色法,以供试品不加显色剂为参比,0.3 mol/L三氯化铝溶液3.0 ml,1.0 mol/L醋酸钠4.0 ml,放置16 min,最大吸收波长为277 nm,此方法项下芦丁对照品在8.8～44 μg/ml的范围内,浓度与吸光度呈现良好的线性关系,线性回归方程为Y=0.0353X+0.0267(r=0.9996),加样回收率平均值为100.91%（n=9,RSD=2.426%）。结论 该方法简便、快速、准确、灵敏,可作为镰形棘豆总黄酮含量的测定方法。     

盐酸氨溴索平衡溶解度和表观油水分配系数的测定

目的 测定盐酸氨溴索在多个pH值介质中的平衡溶解度及表观油水分配系数,为其制剂研究与处方筛选提供依据。方法 采用紫外分光光度法测定盐酸氨溴索在水及10种有机溶剂中的平衡溶解度,通过盐酸氨溴索分配平衡后在油相和水相中的浓度比,计算其油水分配系数。结果 盐酸氨溴索在各pH值介质中的平衡溶解度均较高,尤其是在蒸馏水以及pH值为2.0、5.8的缓冲液中,平衡溶解度分别为26.04、27.91、28.24 mg/mL;油水分配系数在pH7.4时最高,lgP为1.78。结论 盐酸氨溴索的平衡溶解度及表观油水分配系数与各介质的pH值有关,且可推测其在人体内的胃肠吸收良好,有较好的应用价值。     

白头翁皂苷B3的溶解度及油水分配系数与大鼠在体肠吸收研究

目的 测定白头翁皂苷B3的表观溶解度及油水分配系数,并研究其大鼠在体肠吸收机制。方法 HPLC-ELSD法测定B3的表观溶解度和油水分配系数,重量法计算大鼠在体单向肠灌流实验中吸收速率常数(K_a)和表观吸收系数(P_app)。结果 白头翁皂苷B3在37℃有机溶剂中的表观溶解度较低,在碱性磷酸盐缓冲液中的表观溶解度较高;白头翁皂苷B3在不同磷酸盐缓冲液中的油水分配系数相差不大;白头翁皂苷B3在大鼠十二指肠、空肠、回肠和结肠的K_a和P_app没有显著性差异(P > 0.05);白头翁皂苷B3在0.05~2.5 mg/mL随着浓度提高出现过饱和现象;加入P-糖蛋白抑制剂维拉帕米和P-糖蛋白底物地高辛后,都能显著提高白头翁皂苷B3的K_a值。结论 在实验浓度范围内,溶解度和油水分配系数能够较好地预测肠吸收情况;白头翁皂苷B3不完全依赖浓度梯度转运,细胞膜上的载体蛋白参与了药物的转运过程,其小肠吸收机制并不完全为被动转运;受吸收部位影响较小,无特殊的吸收窗;P-糖蛋白介导了白头翁皂苷B3的小肠吸收。     

黄蜀葵花总黄酮中金丝桃苷的平衡溶解度和表观油水分配系数测定

摘 要 目的：测定黄蜀葵花总黄酮中金丝桃苷的平衡溶解度和表观油水分配系数。方法: 采用HPLC法测定金丝桃苷在水、不同有机溶剂和不同pH缓冲液中的平衡溶解度,用摇瓶法测定金丝桃苷在正辛醇 水/缓冲液中的表观油水分配系数。结果: 37℃下金丝桃苷在水中的平衡溶解度为231.58 mg·L^-1,表观油水分配系数为0.907（logPapp=-0.04）;常用有机溶剂甲醇对金丝桃苷的溶解性较好,为6 579.21 mg·L^-1;在不同pH缓冲溶液中,溶解度随着pH的升高逐渐升高,油水分配系数随着pH的升高逐渐降低。结论:金丝桃苷的水溶性差,pH对其溶解度和表观油水分配系数均有较大影响。     

渗透促进剂对醋氯芬酸经皮渗透性的影响

目的研究醋氯芬酸溶液经离体鼠皮的透过特性,寻找能有效增加醋氯芬酸渗透的促渗剂,用以开发醋氯芬酸经皮给药传递系统。方法测定醋氯芬酸在pH 2.5、3.6、5.0、6.8、7.4 PBS缓冲液中的饱和溶解度;采用水平扩散装置进行醋氯芬酸在pH 2.5、3.6、5.0、6.8、7.4条件下及在乙醇、丙二醇、卡必醇、桉叶油醇、松节油、油酸、氮酮等促渗剂作用下的经皮渗透实验;用HPLC法分析样品。结果随着pH值的增加,醋氯芬酸的溶解度增加,经皮渗透量也呈上升趋势;氮酮、油酸和松节油均可显著增加醋氯芬酸的经皮渗透,促渗顺序为氮酮>油酸>松节油,且主要通过增加表皮基质间的分配系数实现促渗效果。结论醋氯芬酸具有一定的经皮透过性,宜制成经皮给药剂型;油酸、油溶性氮酮可作为其有效的渗透促进剂。     

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.     

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.     

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.     

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.     

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,5 μm）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）对检测出色谱进行指纹图谱相似度评价。结果 建立了鼻渊净胶囊的HPLC指纹图谱,确定了20个共有峰,15个峰归属到各药材,其中5个峰确认了化学成分;10批样品的指纹图谱的整体相似度与对照图谱比较,均在90%以上。结论 所建立的鼻渊净胶囊指纹图谱有助于从整体上控制该制剂的质量。     

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.     

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.     

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.     

Effect of bay K 8644, a calcium channel agonist,on dog cardiac muscarinic receptors

To investigate further whether the effects of the dihydropyridine (DHP) drugs on calcium channels are related to those of these drugs on muscarinic receptors, the binding characteristics of the DHP calcium channel agonist, Bay K 8644, on muscarinic receptors and calcium channels were compared to those of the DHP calcium channel antagonists, nicardipine and nimodipine in the dog cardiac sarcolemma. Bay K 8644, nicardipine and nimodipine inhibited the specific [³H]QNB binding with K _i values of 16.7μM, 3.5μM and 15.5μM respectively. Saturation data of [³H]QNB binding in the presence of these DHP drugs showed this inhibition to be competitive. Bay K 8644, like nicardipine and nimodipine, blocked the binding of [³H]nitrendipine to the high affinity DHP binding sites, but atropine did not, indicating that the muscarinic receptors and the DHP binding sites on calcium channels are distinct. The K _i value of Bay K 8644 for the DHP binding sites was 4 nM. Nicardipine and nimodipine (K _i :0.1–0.2 nM) were at least 20 times more potent than Bay K 8644 in inhibiting [³H]nitrendipine binding. Thus, the muscarinic receptors were about 4000 times less sensitive than these high affinity DHP binding sites to Bay K 8644. These results suggest that the DHP calcium agonist Bay K 8644 binds directly to the muscarinic receptors but its interaction with the muscarinic receptors is not related to its binding to the DHP binding sites on calcium channels.