用固相萃取—核磁共振氢谱法研究大鼠尿液中R—（—）—布洛芬光活代谢

目的 用固相萃取－核磁共振氢谱法研究大鼠尿液中Ｒ－（－）－布洛芬后０～２４ｈ大鼠尿液经固相萃取柱处理、核磁共振氢谱测定代谢产物的结构。结果 尿液中含有４个主要代谢产物：２′－羟基－布洛芬及其葡苷酸结合物、１′－羧基－布洛芬葡糖苷酸和布洛芬葡糖苷酸。后两为非对映异构体混合物。结论 Ｒ－（－）－布洛芬在大鼠体内发生了异构体转化,异丁基侧链中末端甲基的氧化代谢具有立体选择性。     

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.     

构树叶的化学成分

为研究构树叶(Broussonetia papyrifera)的化学成分，用Diaion HP-20，Toyopearl HW-40C，Sephadex LH-20，silica gel等柱色谱方法进行分离，根据其理化性质和波谱数据鉴定化合物结构。分离得到了19个化合物，分别鉴定为芹菜素(1)，芹菜素-7-O-β-D-吡喃葡糖苷(2)，柯伊利素-7-O-β-D-吡喃葡糖苷(3)，芹菜素-7-O-β-D-吡喃葡糖醛酸苷(4)，牡荆素-7-O-β-D-吡喃葡糖苷(5)，木犀草素(6)，5,7,4′-三羟基-6-C-［a-L-鼠李糖(1→2)］-β-D-葡糖黄酮碳苷(7)，5,7,4′-三羟基-8-C-［α-L-鼠李糖(1→2)］-β-D-葡糖黄酮碳苷(8)，异牡荆素(9)，牡荆素(10)，苯甲酸苯甲酯-2,6-二-O-β-D-吡喃葡糖苷(11)，(2R,3R,5R,6S,9R)-3-羟基-5,6-环氧-β-紫罗兰醇-2-O-β-D-葡糖苷(12)，(2R,3R,5R,6S,9R)-3-羟基-5,6-环氧-乙酰-β-紫罗兰醇-2-O-β-D-葡糖苷(13)，ficustriol (14)，(6S,9S)-玫瑰花苷(15)，3β-羟基-5α,6α-环氧-β-紫罗兰酮-2α-O-β-D-葡糖苷(16)，icariside B₁ (17)，sammangaoside A (18)，3-羟基-5α,6α-环氧-β-紫罗兰酮(19)。化合物11、12、13为新化合物，其余化合物为首次从该属植物中分离得到。     

血小板活化因子受体拮抗剂——芳氨酮类化合物的合成及其抗炎活性

以取代亚苄基丙酮和二级胺盐酸盐经Mannich反应合成了一系列具有抗炎活性的芳氨酮类化合物，其结构经¹H NMR、MS、元素分析或HRMS确证。同时测定了所合成化合物对血小板活化因子(PAF)引起的大鼠胸腔多形核白细胞β-葡糖苷酸酶释放的抑制作用，初步药理实验结果表明，大部分芳氨酮类(MA)化合物对PAF引起的大鼠胸腔多形核白细胞β-葡糖苷酸酶的释放有明显的抑制作用，其中化合物MA12、MA13、MA18、MA21和MA33的抑制活性较强。提示化合物可通过抑制β-葡糖苷酸酶释放发挥抗炎作用，可能是潜在的PAF受体拮抗剂。     

固相萃取-核磁共振氢谱法研究乙哌立松的代谢产物

目的　探讨用固相萃取-核磁共振氢谱法研究乙哌立松体内药物代谢产物的可能性。方法　用两次固相萃取除去大鼠尿液中的内源性物质,并将药物及其代谢产物分配到几个组分中,然后进行核磁共振氢谱检测。结果　共检测到4个代谢产物,其中2个代谢产物未见文献报道。结论　用固相萃取与核磁共振谱技术结合的方法,在不完全分离代谢产物的情况下,根据核磁共振谱提供的特征峰和化学位移变化可以解析乙哌立松代谢产物结构,也可依据发现的结构片段推测它在体内发生的生物转化过程。     

R,S-1-(2-甲氧基苯基)-4-［3-(萘-1-氧基)-2-羟基丙基］哌嗪在大鼠血浆中代谢产物的研究

目的研究R,S-1-(2-甲氧基苯基)-4-［3-(萘-1-氧基)-2-羟基丙基］哌嗪(naftopidil，NAF)在大鼠血浆中的代谢产物。方法用LC/MS法对大鼠口服NAF后的血浆样品进行分析，根据检测到的代谢产物与原形药的质谱行为及类似结构化合物的代谢规律，推测可能的代谢产物。合成对照品，通过比较代谢产物和合成对照品的色谱和质谱行为，对I相代谢物予以确认。通过质谱信息及酶水解的方法间接鉴定II相代谢物。结果大鼠血浆中发现I相代谢物：R,S-1-(2-羟基苯基)-4-［3-(萘-1-氧基)-2-羟基丙基］哌嗪(DMN)、R,S-1-(2-甲氧基-4-羟基苯基)-4-［3-(萘-1-氧基)-2-羟基丙基］哌嗪(PHN)，R,S-1-(2-甲氧基苯基)-4-［3-(4-羟基萘-1-氧基)-2-羟基丙基］哌嗪(NHN)及II相代谢物：NAF和NHN与<>-D-葡糖醛酸形成的结合物。结论NAF在大鼠血浆中的主要代谢途径是苯环、萘环羟基化和苯环邻位甲氧基的脱甲基化。此外，萘羟化代谢物和原形药与内源性分子<>-D-葡糖醛酸形成结合物也是原形药的代谢方式之一。     

高效液相色谱-电喷雾质谱法研究人尿中α-生育酚的主要代谢产物

研究α-生育酚在人尿中的主要代谢物。选择健康受试者5名连续7 d单剂量口服维生素E 250 mg，d 7收集0～6 h尿样，经C₁₈小柱固相萃取(SPE)分离纯化后，直接采用液相色谱-质谱联用方法(LC-MSⁿ)对尿样进行测定。在尿样中鉴定出4个主要代谢物，它们分别为α-生育酸、2,5,7,8-四甲基-2-(2′-羧乙基)-6-硫酸酯苯并二氢吡喃、 γ-生育酸内酯和2,5,7,8-四甲基-2-(4′,8′,12′-三甲基-12′-羧十二烷基)-6-硫酸酯苯并二氢吡喃。该方法灵敏、选择性高，为深入研究α-生育酚在人体内的代谢规律提供了可靠的方法。     

衍生化法分离（2R，4R）-4-甲基-2-哌啶甲酸乙酯酒石酸盐手性异构体

目的 建立衍生化法分离（2R,4R）-4-甲基-2-哌啶甲酸乙酯酒石酸盐（MPFET）3种手性异构体。方法 以2,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖异硫氰酸酯（GITC）为柱前衍生化试剂,对MPFET手性异构体进行分离,并对衍生化条件进行优化。采用Venusil AQ C₁₈（250 mm×4.6 mm,5 μm）色谱柱作为固定相进行分离、监测和定量。以0.01 mol/L磷酸二氢钾溶液（用磷酸调pH至3.6）-乙腈（60∶40）为流动相,体积流量1.5 mL/min进行等度洗脱,采用紫外检测器,检测波长266 nm;柱温30℃;进样量20 μL。结果 MPFET与2S,4S-异构体分离度为1.76。2S,4R-异构体的线性范围为1.500～8.999 μg/mL,2R,4S-异构体的线性范围为0.255 2～1.531 0 μg/mL,2S,4S-异构体的线性范围为0.250 1～75.000 0 μg/mL,MPFET的线性范围为0.250 1～600.100 0 μg/mL,回收率均在90%～108%内,RSD均不大于3.0%。结论 柱前衍生化法分离MPFET中3种手性异构体,专属性强、准确度高、灵敏度高、重复性好,可用于MPFET手性异构体的分离和质量控制。     

牛膝甾酮25位差向异构体的分离与鉴定

目的分离并确定苋科植物怀牛膝(Achyranthes bidentata Blume.)中牛膝甾酮25位差向异构体的结构。方法利用色谱技术分离纯化牛膝甾酮25位差向异构体，用波谱(IR,UV,MS,NMR)方法及化学方法确定结构。结果从怀牛膝的乙酸乙酯部位分离得到3个化合物，分别鉴定为25S-牛膝甾酮(1, 25S-inokosterone)，25R-牛膝甾酮(2, 25R-inokosterone)，β-蜕皮甾酮(3, ecdysterone)。结论化合物1和2为首次从怀牛膝中分离得到的25位差向异构体，首次确定了25位绝对构型和发表该25位差向异构体的¹³CNMR数据。     

1-(3′,4′-二甲氧基)苯甲酰基-3-酰氨基-4-取代苯基-2-吖丁啶酮类化合物的合成及其抑制β-内酰胺酶的作用

本文设计和合成了14个新的1-(3′,4′-二甲氧基)苯甲酰基-3-酰氨基-4-取代苯基-2-吖丁啶酮类化合物,分别经红外光谱、核磁共振氢谱、质谱和元素分析证实。其中11个化合物具有β-内酰胺酶抑制作用。Ⅶe-1及Ⅶg-1的活性约为临床应用的青霉烷砜酸的两倍。     

Stereoselectivity of ibuprofen metabolism and pharmacokinetics following the administration of the racemate to healthy volunteers

1. The stereoselective metabolism and pharmacokinetics of the enantiomers of ibuprofen have been investigated following the oral administration of the racemic drug (400 mg) to 12 healthy volunteers.2. The stereochemical composition of the drug in serum, both total and unbound, and drug and metabolites, both free and conjugated, in urine were determined by a combination of the direct and indirect chromatographic procedures to enantiomeric analysis. 3. The oral clearance of (S)-ibuprofen was significantly greater than that of the R-enantiomer (74.5 +/- 18.1 versus 57.1 +/- 11.7 ml min(-1); p < 0.05) and the clearance of (R)-ibuprofen via inversion was ca two fold that via alternative pathways. 4. Some 74.0 +/- 9.6% of the dose was recovered in urine over 24 h as ibuprofen, 2-hydroxyibuprofen and carboxyibuprofen, both free and conjugated with glucuronic acid. Analysis of the stereochemical composition of the urinary excretion products indicated that 68% of the dose of (R)-ibuprofen had undergone chiral inversion. 5. Metabolism via glucuronidation and both routes of oxidation, showed enantio-selectivity for (S)-ibuprofen, the enantiomeric ratios (S/R) in partial metabolic clearance being 7.1, 4.8 and 3.4 for formation of ibuprofen glucuronide, 2-hydroxyibuprofen and carboxyibuprofen respectively.6. Modest stereoselectivity was observed in the formation of (2'R, 2R)- and (2'S, 2S)-carboxyibuprofen in comparison to the alternative diastereoisomers, the ratios in formation clearance being 1.6 and 1.2 respectively.     

Stereoselectivity of ibuprofen metabolism and pharmacokinetics following the administration of the racemate to healthy volunteers

1. The stereoselective metabolism and pharmacokinetics of the enantiomers of ibuprofen have been investigated following the oral administration of the racemic drug (400?mg) to 12 healthy volunteers. 2. The stereochemical composition of the drug in serum, both total and unbound, and drug and metabolites, both free and conjugated, in urine were determined by a combination of the direct and indirect chromatographic procedures to enantiomeric analysis. 3. The oral clearance of (S) -ibuprofen was significantly greater than that of the R -enantiomer (74.5 ± 18.1 versus 57.1 ± 11.7 ml?min -1 ; p < 0.05) and the clearance of (R) -ibuprofen via inversion was ca two fold that via alternative pathways. 4. Some 74.0 ± 9.6% of the dose was recovered in urine over 24 h as ibuprofen, 2-hydroxyibuprofen and carboxyibuprofen, both free and conjugated with glucuronic acid. Analysis of the stereochemical composition of the urinary excretion products indicated that 68% of the dose of (R) -ibuprofen had undergone chiral inversion. 5. Metabolism via glucuronidation and both routes of oxidation, showed enantio-selectivity for (S) -ibuprofen, the enantiomeric ratios (S/R) in partial metabolic clearance being 7.1, 4.8 and 3.4 for formation of ibuprofen glucuronide, 2-hydroxyibuprofen and carboxyibuprofen respectively. 6. Modest stereoselectivity was observed in the formation of (2' R, 2 R) - and (2' S, 2 S) -carboxyibuprofen in comparison to the alternative diastereoisomers, the ratios in formation clearance being 1.6 and 1.2 respectively.     

Mechanistic studies on the metabolic chiral inversion of R-ibuprofen in the rat.

Deuterium labeling techniques and stereoselective GC/MS methodology have been employed to investigate the mechanism by which R-ibuprofen undergoes metabolic chiral inversion in the rat in vivo. Following oral administration of a mixture of R-ibuprofen (7.5 mg kg-1) and R-[ring-2H4; 2-2H]ibuprofen (R-[2H5]ibuprofen) (7.5 mg kg-1) to male Sprague-Dawley rats, the enantiomeric composition and deuterium excess of the drug were determined in serial plasma samples and in pooled urine collected over 10 hr. The results demonstrate that: (i) R-ibuprofen undergoes extensive inversion of configuration to its S antipode in the rat; (ii) chiral inversion of R-[2H5]ibuprofen yields S-[2H4]ibuprofen in a process that involves quantitative loss of the deuterium atom present originally at C-2; (iii) labeling of R-ibuprofen with deuterium at C-2 does not introduce a measurable kinetic deuterium isotope effect on the chiral inversion reaction; and (iv) metabolism of R-[2H5]ibuprofen leads to the appearance in plasma and urine of molecules of R-ibuprofen labeled with 4 atoms of deuterium. On the basis of these findings, a mechanism is proposed for the chiral inversion reaction that invokes the stereoselective formation of the coenzyme A thioester of R-ibuprofen as a key metabolite; conversion of this species to the corresponding enolate tautomer affords a symmetrical intermediate through which racemization of ibuprofen occurs in vivo.     

Studies on the metabolism and chiral inversion of ibuprofen in isolated rat hepatocytes

The oxidative metabolism and chiral inversion of ibuprofen in freshly isolated rat hepatocytes was studied with the aid of a stereoselective GC/MS assay procedure. Hydroxylation of the isobutyl side chain at the subterminal carbon (to give hydroxyibuprofen) proved to be the major route of metabolism of both R(-)-ibuprofen and S(+)-ibuprofen, while formation of the corresponding diastereoisomeric 2-methylpropionic acid derivatives (carboxyibuprofen) was of minor quantitative importance. Both oxidative pathways were inhibited in the presence of metyrapone, a cytochrome P-450 inhibitor. R(-)-Ibuprofen underwent metabolic chiral inversion to the S(+) enantiomer, whose formation was dependent on incubation time, cell density, and substrate concentration. S(+)-Ibuprofen, on the other hand, was not converted to R(-)-ibuprofen in rat hepatocytes. When cells were incubated with a mixture of unlabeled R(-)-ibuprofen and R(-)-[3,3,3-2H3]ibuprofen, the resultant S(+) enantiomer consisted only of unlabeled and trideutero molecules (formed in the same ratio as the corresponding species of R(-)-ibuprofen), indicating that 2,3-dehydroibuprofen did not serve as the symmetrical intermediate in the chiral inversion reaction. Collectively, these results demonstrate that freshly isolated rat hepatocytes represent a convenient and reproducible in vitro model system for studies on the metabolism and chiral inversion of ibuprofen.     

The metabolic chiral inversion of 2-phenylpropionic acid in rat, mouse and rabbit

The metabolic chiral inversion of the 2-arylpropionic acids has been investigated in laboratory animals, using the simplest congener, 2-phenylpropionic acid, as a model compound. The chiral inversion was found to occur after administration of the racemate to the rat and rabbit, but not in the mouse. The formation of the ester glucuronide was enantioselective for the S-(-)-isomer in the rat and mouse, but showed no stereoselectivity in the rabbit. [corrected] In the rat, the extent of inversion from R-(-) to S-(+) was greater at a dose of 30 mg/kg than at 150 or 300 mg/kg. The enantiomeric composition of the acid in urine was the same when the racemate was given orally or by i.p. injection. When the R-(-)isomer was given to rats, some 30% of the excreted acid was in the S-(+)-form, but when the S-(+)-isomer was given, the inversion was much less evident. In this case, the S/R ratio of the excreted phenylproprionic acid was ca 9:1. Following the administration of the racemate to rats, the plasma elimination half-life of the R-(-)-form was shorter (3.0 vs 4.8 hr for the S-(-)-isomer); this was due to its considerably greater plasma clearance (65.9 vs 43.6 micrograms/ml hr), since the volumes of distribution of the enantiomers were the same. The S/R ratio of 2-phenylpropionic acid in plasma rose progressively with time, from 1:1 in the dose solution to 2.1:1 at 8 hr.     

Impaired intrinsic chiral inversion activity of ibuprofen in rats with adjuvant-induced arthritis

1. The effects of adjuvant-induced arthritis on the chiral inversion of ‘profens’, a type of non-steroidal anti-inflammatory drug, have hardly been investigated. The authors investigated the effects of adjuvant-induced arthritis on the chiral inversion of ibuprofen using freshly isolated rat hepatocytes.

2. S- or R-ibuprofen was incubated with hepatocytes isolated from control and adjuvant-induced arthritis rats in the absence of the serum. In the hepatocyte system the chiral inversion rate constant of R- to S-ibuprofen and the metabolic rate constants of both enantiomers in adjuvant-induced arthritis rats were significantly decreased to about 64–80% of the corresponding values in control rats. In contrast, the addition of serum from each group to the corresponding hepatocyte medium resulted in no significant differences in these rate constants between control and adjuvant-induced arthritis rats.

3. With regard to chiral inversion enzymes, adjuvant-induced arthritis decreased the messenger RNA levels of acyl-coenzyme A synthetase (ACS) isoforms, but not 2-arylpropionyl-CoA epimerase, compared with control rats.

4. Chiral inversion of R- to S-ibuprofen was inhibited by triacsin C, a specific inhibitor of ACS1.

5. The results suggest that adjuvant-induced arthritis induces down-regulation of ACS enzymes involved in chiral inversion of R- to S-ibuprofen in rats.     

布洛芬离体肝代谢中对映体间的相互作用

目的研究布洛芬离体肝代谢中对映体之间的相互作用。方法用家兔肝匀浆质与单纯的R(- ) 或S(+) 布洛芬以及两对映体以不同比例的混合物 ,加入必要的辅助因子进行离体肝手性转化代谢试验 ,利用立体选择性HPLC法测定各对映体以及中间产物硫酯的质量浓度。结果布洛芬手性转化代谢由R(- ) 型向S(+) 型单向进行 ,在S(+) 布洛芬的存在下 ,R(- ) 布洛芬的转化量减少 ,中间产物硫酯的生成量减少。结论S(+) 布洛芬在一定程度上抑制手性转化的进行     

A novel method for assessing inhibition of ibuprofen chiral inversion and its application in drug discovery

An inhibition assay to assess the potential for chiral inversion of compounds was developed using R(-)-ibuprofen as the probe substrate. Inhibition of the chiral inversion of R(-)-ibuprofen by structurally similar compounds in cyropreserved rat hepatocytes was studied using chiral HPLC and LC/MS methods for the chromatographic separation and detection of enantiomers. Concept validation of this assay was performed with three commercially available compounds and four Pfizer compounds. The results of these studies demonstrated that compounds that are structurally similar to ibuprofen inhibited the formation of S(+)-ibuprofen, suggesting that they may undergo similar enzymatic chiral inversion pathways or compete for the same enzyme active sites. Additionally, an application of this assay in early drug discovery for a specific class of compounds was demonstrated. Thirty-three in-house compounds were screened for their chiral inversion potential utilizing this assay to investigate the structure activity relationship (SAR) for this class of compounds.     

Pharmacokinetic interaction of ibuprofen enantiomers in rabbits

The potential interaction between two ibuprofen enantiomers was studied after intravenous administration of R-(-)-, S-(+)- and racemic ibuprofen to rabbits. The total body clearance values calculated by compartmental model analysis (0.65 +/- 0.21 for R-(-)-ibuprofen and 0.63 +/- 0.34 for S-(+)-ibuprofen) after intravenous administration of the racemate of ibuprofen were significantly smaller than those of individual enantiomers (0.95 +/- 0.23 for R-(-)-ibuprofen and 1.03 +/- 0.23 for S-(+)-ibuprofen), indicating that the enantiomer-enantiomer interaction results in a mutual inhibition. The enantiomeric interaction in the pharmacokinetic behaviour of ibuprofen after racemic administration is considered to be a result of an alteration in the metabolic or excretion phase (or both) rather than stereoselective protein binding in the systemic distribution.     

Impaired intrinsic chiral inversion activity of ibuprofen in rats with adjuvant-induced arthritis

1. The effects of adjuvant-induced arthritis on the chiral inversion of 'profens', a type of non-steroidal anti-inflammatory drug, have hardly been investigated. The authors investigated the effects of adjuvant-induced arthritis on the chiral inversion of ibuprofen using freshly isolated rat hepatocytes. 2. S- or R-ibuprofen was incubated with hepatocytes isolated from control and adjuvant-induced arthritis rats in the absence of the serum. In the hepatocyte system the chiral inversion rate constant of R- to S-ibuprofen and the metabolic rate constants of both enantiomers in adjuvant-induced arthritis rats were significantly decreased to about 64-80% of the corresponding values in control rats. In contrast, the addition of serum from each group to the corresponding hepatocyte medium resulted in no significant differences in these rate constants between control and adjuvant-induced arthritis rats. 3. With regard to chiral inversion enzymes, adjuvant-induced arthritis decreased the messenger RNA levels of acyl-coenzyme A synthetase (ACS) isoforms, but not 2-arylpropionyl-CoA epimerase, compared with control rats. 4. Chiral inversion of R- to S-ibuprofen was inhibited by triacsin C, a specific inhibitor of ACS1. 5. The results suggest that adjuvant-induced arthritis induces down-regulation of ACS enzymes involved in chiral inversion of R- to S-ibuprofen in rats.