Liguzinediol乙酰氨基酸双酯前药的设计、合成及生物活性评价

目的:设计、合成liguzinediol的乙酰氨基酸酯前药,结合化学稳定性、理化性质以及体外、体内药动学研究,考察其生物活性,筛选出适合的候选前药。方法:采用4-二甲氨基吡啶(DMAP)催化、N,N'-二环己基碳二亚胺(DCC)缩合liguzinediol乙酰氨基酸酯前药,化合物结构经LC-MS,1H-NMR和13C-NMR确证。采用高效液相色谱法(HPLC)测定化合物的化学稳定性、容量因子、脂水分配系数以及溶解度,并进行了体外生物转化稳定性和体内药动学研究。结果:liguzinediol的乙酰缬氨酸、亮氨酸与异亮氨酸双酯前药酶解速率过低;乙酰苯丙氨酸双酯的水溶性较差;乙酰甘氨酸双酯化学稳定性高,酶解释放速率适中。结论:liguzinediol的乙酰甘氨酸酯化学稳定性较高,体外80%人体血浆以及肝微粒体酶解liguzinediol释放速率合适,可作为liguzinediol的候选药物。

O-乙酰氨基半乳糖基化氨基酸的化学合成

目的 为获得精确定位糖基化糖肽 ,合成O 乙酰氨基半乳糖基化氨基酸 ,作为糖肽固相合成的原料。方法 利用环状糖结构的半缩醛羟基可与含侧链羟基氨基酸的羟基形成糖苷键 ,用化学方法 ,使过乙酰化GalNAc与氨基被 9 Fluorenylmethoxycarbonyl (N α Fmoc)保护的丝氨酸或苏氨酸连接。结果 反应产物通过反相制备HPLC纯化后 ,可作为O 连接糖肽合成构建单位 (Buildingblocks)在固相多肽合成仪上合成所需的病毒或肿瘤相关糖肽 ,并可进一步研究其生物学活性。结论 本法相对易操作 ,重复性好 ,收益率也较高 ,更重要的是糖基化的均一性好 。

2′,3′-乙氧甲撑基腺苷5′-硫代磷酰氨基酸酯的合成和谱学分析

Nucleoside reverse transcriptase inhibitors are the only drugs so far approved for the treatment of AIDS. Several nucleoside analogs are potent inhibitors of human immunodeficiency virus(HIV) in cell culture. However, in many cases the nucleoside derivatives have a poor affinity for nucleoside kinases. Nucleoside 5′-phosphorothioates is relatively resistant to enzymatic transformations. In this paper, 2′,3′-O-alkoxymethylidene adenosine 5′-thiophosphoramidates were synthesized through a highly efficient approach. The new compounds were characterized by NMR, IR and ESI-MS.

新型D-氨基酰化酶的特性及固定化酶的研究

本文研究了一株具有N-酰基酰化酶(DAA)生产能力的细菌,通过对其酶学特性及固定化酶用于D-氨基酸的生产进行了研究。显示此酶的最适温度为37℃,最适p H7.4,1mmol/L以下的Ca Cl2,Cd Cl2,Co Cl2,Cu Cl2,Fe Cl2,Hg Cl2,Mn Cl2,Zn Cl2对酶的活性没有影响,在20mmol/L的EDTA条件下仍可保持65%的酶活性。底物特异性显示酶的最佳底物是N-乙酰-D-苯丙氨酸,50mmol/L以上的N-乙酰-D-苯丙氨酸显著抑制酶的活性。利用海藻酸钠固定酶后,在30℃条件下,使用50mmol/L的N-酰基-D-苯丙氨酸底物进行的降解实验显示水解率可以达到84%,转化批次达到6次以上,活性保持达到70小时以上。

高效液相色谱法测定人体血浆中的对乙醚氨基酚含量

高效液相色谱法测定人体血浆中的对乙醚氨基酚含量褚书铃，王鸿辰北京医科大学药学院药剂教研室陈连珊，侯明霞对乙酰氨基酚是目前使用较多的快速、有效的解热镇痛药之一，在正常剂量范围内毒副作用较低，但长期服用或超剂量长期服用时会损害肝脏，严重时可导致肝坏死。而...

急性子乙醇提取液促透皮实验研究

目的 研究中药急性子乙醇提取液的促透皮作用 ,以对乙酰氨基酸 (扑热息痛 )作为试验药物。方法 采用体外透皮吸收实验方法和差示分光光度法测定透过液中扑热息痛的吸收度。结果 不同浓度的急性子乙醇溶液与空白对照组比较在不同时间的吸收度有显著性差异 (P <0 .0 5 ) ,与氮酮标准组比较无显著性差异 (P >0 .0 5 )。结论 急性子乙醇提取液具有促进扑热息痛透皮吸收的作用。

目标因子法同时测定扑热息痛中三组分

详细介绍了目标因子紫外分光光度法同时测定多组分体系的基本原理和分析步骤 ,并将其应用于对乙酰氨基酚、对硝基酚、对氨基酚三组分含量的分析 研究表明 :在无水乙醇介质中 ,在 2 0 6～32 0nm处每隔 2nm扫描测定样品吸光度 ,利用目标因子法处理数据得标准加入回收率为 97.2 %～10 5.7% .

窒息新生儿NAG及GGT的改变及临床意义

目的 :比较尿中N -乙酰 - β氨基酸葡萄糖苷酶 (NAG)、γ -氨酰转移酶 (GGT)及血清尿素氮 (BUN)、肌苷 (Cr)等指标在窒息新生儿肾功能损伤的早期诊断中的作用。方法 :测定对照组、轻度窒息组和重度窒息组新生儿的血清中BUN、Cr、尿中NAG和GGT。结果 :发现血清BUN、Cr各组间比较差异无显著性 (P >0 .0 5 ) ;尿中NAG及GGT轻度窒息组高于对照组 ,差异具显著性 (P <0 .0 5 ) ;重度窒息组较轻度窒息组和对照组明显升高 ,差异具显著性 (P <0 .0 5 )。结论 :提示尿中NAG、GGT活性是对窒息新生儿肾损伤的早期诊断及损伤程度的判定的一个灵敏指标。

复方氨酚烷胺胶囊溶出度测定方法的研究

目的 :建立复方氨酚烷胺胶囊溶出度的测定方法。方法 :转篮法 ,采用ODS柱 ,流动相为V(甲醇 )∶V (0 .0 5mol/L磷酸二氢钾 ) =10 0∶40 0 ,检测波长为 2 5 4nm。结果 :对乙酰氨基酚的线性范围为 0 .110 8～ 0 .775 6μg ,回收率为 10 0 .7% (RSD =0 5 0 % )。结论 :本方法结果准确 。

天龙复方制剂联合西药治疗甲型流感随机平行对照研究

[目的]观察天龙复方制剂联合西药治疗甲型流感疗效。[方法]使用随机平行对照方法,将120例门诊及住院患者按掷骰子法简单随机分为两组。对照组60例复方氨酚烷胺片,1片/次,2次/d。治疗组60例天龙复方制剂（青天葵10g,款冬花15g,法半夏10g,熟附子先煎10~30g,五味子5g）,〈6岁,1包/次,1次/d;〉6岁,1包/次,3次/d;西药治疗同对照组。连续治疗14d为1疗程。观测临床症状、头痛、腹泻、呕吐、病毒核酸扩增Ct值、不良反应。连续治疗3疗程,判定疗效。[结果]治疗组痊愈36例,有效18例,无效6例,总有效率90.00%。对照组痊愈18例,有效21例,无效21例,总有效率65.00%。治疗组疗效优于对照组（P〈0.01）。病毒核酸扩增Ct值两组均有改善（P〈0.01）,治疗组改善优于对照组（P〈0.01）。[结论]天龙复方制剂联合西药治疗甲型流感效果显著,值得推广。

Improved 5-Aminolevulinic Acid Production with Recombinant Escherichia coli by a Short-term Dissolved Oxygen Shock in Fed-batch Fermentation

5-Aminolevulinic acid （ALA） is a common precursor for tetrapyrrole compounds in all kinds of organ isms and has wide applications in agriculture and medicines. In this study, a new strategy, i.e. short-term dissolved oxygen （DO） shock during aerobic fermentation, was introduced to produce 5-aminolevulinic acid with a recombi-nant E. coli. Effects of duration time of DO shock operation on plasmid concentration, intracellular ALA synthase （ALAS） activity and ALA production were investigated in Erlenmeyer shake flasks. The results indicated that both ALAS activity and ALA yield were enhanced in an anaerobic operation of 45 rain in the early exponential phase during fermentation, while they decreased when the anaerobic operation time was further increased to 60 rain. The DO shock protocol was confirmed with the fed-batch fermentation in a 15 L fermenter and the ALA production achieved 9.4 g.L-1 （72 mmol.L-1）, which is the highest yield in the fermentation broth reported up to now.

Antifibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline on bile duct ligation induced liver fibrosis in rats

AIM:To investigate the preventive effect of N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) on bile duct ligation (BDL)induced liver fibrosis in rats. METHODS:Liver fibrosis in rats was induced by BDL and AcSDKP was infused subcutaneously for 2 wkvia a osmotic minipump (Alzet 2ML4) immediately after BDL operation. After scarifying, serum and liver specimens were collected. Hematoxylin and eosin staining, Sirius red staining, enzyme linked immunosorbent assay, Western blot or real-time polymerase chain reaction were used to determinate liver functions, histological alterations, collagen deposition, mRNA expression of markers for fibroblasts, transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein-7 (BMP-7). RESULTS:When compared to model rats, chronic exogenous AcSDKP infusion suppressed profibrogenicTGF-β1 signaling, α-smooth muscle actin positivity (α-SMA), fibroblast specific protein-1 (FSP-1) staining and collagen gene expression. Col Ⅰ, Col Ⅲ, matrix metalloproteinase-2, tissue inhibitors of metallopro-teinase-1 and tissue inhibitors of metalloproteinase-2 mRNA expressions were all significantly downregulated by AcSDKP infusion (2.02 ± 1.10vs 14.16 ± 6.50, 2.02 ± 0.45vs 10.00 ± 3.35, 2.91 ± 0.30vs 7.83 ± 1.10, 4.64 ± 1.25 vs 18.52 ± 7.61, 0.46 ± 0.16 vs 0.34 ± 0.12, respectively, P < 0.05). Chronic exogenous AcSDKP infusion attenuated BDL-induced liver injury, inflammation and fibrosis. BDL caused a remarkable increase in alanine transaminase, aspartate transaminase, total bilirubin, and prothrombin time, all of which were reduced by AcSDKP infusion. Mast cells, collagen accumulation, α-SMA, TGF-β1, FSP-1 and BMP-7 increased. The histological appearance of liver specimens was also improved. CONCLUSION:Infusion of exogenous AcSDKP attenu-ated BDL-induced fibrosis in the rat liver. Preservation of AcSDKP may be a useful therapeutic approach in the management of liver fibrosis.

N-acetyl-L-cysteine combined with mesalamine in the treatment of ulcerative colitis: Randomized,placebo-controlled pilot study

AIM: To evaluate the effectiveness and safety of oral N-acetyl-L-cysteine (NAC) co-administration with mesalamine in ulcerative colitis (UC) patients. METHODS: Thirty seven patients with mild to moderate UC were randomized to receive a four-wk course of oral mesalamine (2.4 g/d) plus N-acetyl-L-cysteine (0.8 g/d) (group A) or mesalamine plus placebo (group B). Patients were monitored using the Modified Truelove-Witts Severity Index (MTWSI). The primary endpoint was clinical remission (MTWSI ≤ 2) at 4 wk. Secondary endpoints were clinical response (defined as a reduction from baseline in the MTWSI of ≥ 2 points) and drug safety. The serum TNF-α, interleukin-6, interleukin-8 and MCP-1 were evaluated at baseline and at 4 wk of treatment. RESULTS: Analysis per-protocol criteria showed clinical remission rates of 63% and 50% after 4 wk treatment with mesalamine plus N-acetyl-L-cysteine (group A) and mesalamine plus placebo (group B) respectively (OR = 1.71; 95% CI: 0.46 to 6.36; P = 0.19; NNT = 7.7). Analysis of variance (ANOVA) of data indicated a significant reduction of MTWSI in group A (P = 0.046) with respect to basal condition without significant changes in the group B (P = 0.735) during treatment. Clinical responses were 66% (group A) vs 44% (group B) after 4 wk of treatment (OR = 2.5; 95% CI: 0.64 to 9.65; P = 0.11; NNT = 4.5). Clinical improvement in group A correlated with a decrease of IL-8 and MCP-1. Rates of adverse events did not differ significantly between both groups. CONCLUSION: In group A (oral NAC combined with mesalamine) contrarily to group B (mesalamine alone), the clinical improvement correlates with a decrease of chemokines such as MCP-1 and IL-8. NAC addition not produced any side effects.

N-acetyl cysteine therapy in acute viral hepatitis

AIM: To investigate the effect of N-acetyl cysteine (NAC)on acute viral hepatitis (AVH).METHODS: We administered 200 mg oral NAC three times daily (600 mg/day) to the study group and placebo capsules to the control group. All patients were hospitalized and diagnosed as AVH. Blood total and direct bilirubin, ALT, AST,alkaline phosphatese, albumin and globulin levels of each patient were measured twice weekly until total bilirubin level dropped under 2 mg/dl, ALT level under 100 U/L, follow up was continued and then the patients were discharged.RESULTS: A total of 41(13 female and 28 male) AVH patients were included in our study. The period for normalization of ALT and total bilirubin in the study group was 19.7±6.9 days and 13.7±8.5 days respectively. In the control group it was 20.4±6.5 days and 16.9±7.8 days respectively (P＞0.05).CONCLUSION: NAC administration effected neither the time necessary for normalization of ALT and total bilirubin values nor duration of hospitalization, so we could not suggest NAC for the treatment of icteric AVH cases. However, our results have shown that this drug is not harmful to patients with AVH.

Oral administration of S-nitroso-N-acetylcysteine prevents the onset of non alcoholic fatty liver disease in rats

AIM： To evaluate the potential of S-nitroso-N-acetylcysteine （SNAC） in inhibition of lipid peroxidation and the effect of oral SNAC administration in the prevention of nonalcoholic fatty liver disease （NAFLD） in an animal model.METHODS： NAFLD was induced in Wistar male rats by choline-deficient diet for 4 wk. SNAC-treated animals （n=6） （1.4 mg/kg/day of SNAC, orally） were compared to 2 control groups： one （n=6） received PBS solution and the other （n=6） received NAC solution （7 mg/kg/d）. Histological variables were semiquantitated with respect to macro and microvacuolar fat changes, its zonal distribution, foci of necrosis, portal and perivenular fibrosis, and inflammatory infiltrate with zonal distribution. LOOHs from samples of liver homogenates were quantified by HPLC. Nitrate levels in plasma of portal vein were assessed by chemiluminescence. Aqueous low-density lipoprotein （LDL） suspensions （200 pg protein/mL） were incubated with CuCl2 （300 μmol/L） in the absence and presence of SNAC （300 μmol/L） for 15 h at 37 ℃ Extent of LDL oxidation was assessed by fluorimetry. Linoleic acid （LA） （18.8 μmol/L） oxidation was induced by soybean lipoxygenase （SLO） （0.056 μmol/L） at 37 ℃ in the presence and absence of N-acetylcysteine （NAC） and SNAC （56 and 560 pmol/L） and monitored at 234 nm. RESULTS： Animals in the control group developed moderate macro and microvesicular fatty changes in periportal area. SNAC-treated animals displayed only discrete histological alterations with absence of fatty changes and did not develop liver steatosis. The absence of NAFLD in the SNAC-treated group was positively correlated with a decrease in the concentration of LOOH in liver homogenate, compared to the control group （0.7±0.2 nmol/mg vs 3.2±0.4 nmol/mg protein, respectively, P〈0.05）, while serum levels of aminotransferases were unaltered. The ability of SNAC in preventing lipid peroxidation was confirmed in in vitro experiments using LA and LDL as model substrates. CONCLUSION： Oral administration of SNAC prevents the onset of NAFLD in Wistar rats fed with cholinedeficient diet. This effect is correlated with the ability of SNAC to block the propagation of lipid peroxidation in vitro and in vitro.

Comparison of photodynamic therapy for skin cancers and pre-cancers with δ-aminolevulinic acid

Objective:The aim of the study was to compare the effects of photodynamic therapy(PDT) with δ-aminolevulinic acid(ALA) for patients with different kinds of skin cancers and pre-cancers.Methods:The present study enrolled seventyfive cases,which included 17 cases of actinic keratosis(AK),9 cases of Bowen's disease,11 cases of superficial basal cell carcinomas(BCC),23 cases of nodule basal cell carcinomas and 15 cases of squamous cell carcinomas(SCC),and every patient had single lesion.All patients were treated with 20% ALA topically and He-Ne laser weekly for three times,and followed up 1-3 years.Results:After therapy,the rates of complete reaction(CR) were 100% in AK lesions,77.8% in Bowen's diseases,90.9% in superficial BCCs,47.8% in nodule BCCs,and 50.3% in SCCs,which had significant differences among these five kinds of lesions(H = 18.27,P < 0.05).The therapeutic effectiveness of ALA-PDT for AK was superior to that of Bowen's disease(Q = 4.364,P < 0.05),superficial BCC(Q = 5.55,P < 0.01),SCC(Q = 8.94,P < 0.01) and nodule BCC(Q = 17.91,P < 0.01);the effect of Bowen's disease was better than that of SCC(Q = 7.8,P < 0.01),nodule BCC(Q = 13.44,P < 0.01);the effect of superficial BCC was better than that of SCC(Q = 9.73,P < 0.01),nodule BCC(Q = 16.28,P < 0.01),but similar with Bowen's disease(Q = 0.96,P > 0.05);the effect of SCC was better than that of nodule BCC(Q = 17.74,P < 0.01).Conclusion:Our study shows that therapeutic effectiveness of ALA-PDT for AK is best in five diseases,and Bowen's disease and superficial BCC are secondary,while nodule BCC and SCC are at the bottom.

PURIFICATION OF L-METHIONINE AND N-ACETYL-D-METHIONINE FROM THE MIXTURE OF ENZYMATICALLY DEACYLATED N-ACETYL-DL-METHIONINE

N-acetyl-D-methionine, NaAc and the remains of N-acetyl-L-methionine dramatically affect the purification of L-methionine when purified from the mixture of enzymatically deacylated N-acetyl-DL-methionine, leading to a low yield conventionally. Here, this paper reports a successful separation and purification of both L-methionine and N-acetyl-D-methionine by an H ion-exchange column. The pH, L-Met concentration and the ratio between the content of sodium cation and the ion-exchange capacity were optimized to obtain the maximum yield. Experimental results indicate that, under the optimized conditions, the yields of L-methionine and N-acetyl-D-methionine can reach as high as 85% and 75%, respectively.

Efficient synthesis of thiohydantoin derivatives from amino acid esters and isothiocyanates in alkaline Al_2O_3

Various amino acid esters were reacted with different isothiocyanates in alkaline Al2O3 at room temperature for 1 h affording thiohydantoins in moderate to excellent yields.

Chlorogenic acid prevents acetaminophen-induced liver injury: the involvement of CYP450 metabolic enzymes and some antioxidant signals

Chlorogenic acid（CGA）, a polyphenolic compound, is abundant in fruits, dietary vegetables, and some medicinal herbs. This study investigated the prevention of CGA against acetaminophen（AP）-induced hepatotoxicity and its engaged mechanisms. CGA reversed the decreased cell viability induced by AP in L-02 cells in vitro. In addition, CGA reduced the AP-induced increased serum levels of alanine/aspartate aminotransferase（ALT/AST） in vivo. The effect of CGA on cytochrome P450（CYP） enzymatic（CYP2E1, CYP1A2, and CYP3A4） activities showed that CGA caused very little inhibition on CYP2E1 and CYP1A2 enzymatic activities, but not CYP3A4. The measurement of liver malondialdehyde（MDA）, reactive oxygen species（ROS）, and glutathione（GSH） levels showed that CGA prevented AP-induced liver oxidative stress injury. Further, CGA increased the AP-induced decreased m RNA expression of peroxiredoxin（Prx） 1, 2, 3, 5, 6, epoxide hydrolase（Ephx） 2, and polymerase（RNA） II（DNA directed） polypeptide K（Polr2k）, and nuclear factor erythroid-2-related factor 2（Nrf2）. In summary, CGA ameliorates the AP-induced liver injury probably by slightly inhibiting CYP2E1 and CYP1A2 enzymatic properties. In addition, cellular important antioxidant signals such as Prx1, 2, 3, 5, 6, Ephx2, Polr2 k, and Nrf2 also contributed to the protection of CGA against AP-induced oxidative stress injury.