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目的 优选甘草提取物中甘草次酸的精制工艺。方法 以甘草次酸的转移率和含量为指标,单因素筛选甘草的粗提取工艺,进一步筛选和优化阴离子交换树脂对甘草次酸的纯化过程。结果 甘草的粗提取工艺为将甘草药材用20%乙醇回流提取3次,每次10倍药材体积,合并提取液浓缩至相对药材5倍体积,加入50%硫酸,使浓缩液中的硫酸浓度为5%,加热回流5 h,放冷,弃去酸液,水洗沉淀至中性,烘干,研细,得甘草次酸粗产品;精制工艺为将甘草次酸粗产品用适量水稀释,调节pH至11,过阴离子交换树脂柱,盐酸酸化,10倍量85%以上乙醇洗脱,减压回收乙醇,将析出的沉淀过滤,50℃以下干燥,得黄棕色粉末,甘草次酸含量为55.5%,转移率为53.3%。结论 制备得到的甘草次酸含量较高,采用阴离子交换树脂提取纯化甘草次酸的工艺可行。 相似文献
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目的 筛选出半枝莲和白花蛇舌草药对中总黄酮提取及纯化的最佳工艺条件。方法 以总黄酮提取率和浸膏量为评价指标,选择两者配比、乙醇体积分数、料液比、提取时间4个因素作为考察对象,L9(34)正交试验优选总黄酮提取工艺。然后结合静态和动态实验方法,以吸附率、解吸率为指标,确定聚酰胺树脂纯化的工艺条件及参数。结果 确定药对中总黄酮提取的工艺条件:半枝莲与白花蛇舌草药对的配比为4:1,25倍量体积分数为70%的乙醇,提取3次,每次2 h。聚酰胺树脂纯化药对中总黄酮的工艺条件:上样液中总黄酮浓度为63.14 mg/ml,pH为4.0,以1.5 ml/min的流速上样,先用流速为3 ml/min的3.1床容积(BV)的水洗脱,再用流速为3 ml/min的9.3 BV体积分数为65%的乙醇洗脱,收集洗脱液,测得总黄酮纯度为40.39%,转移率为81.57%。结论 优化的提取工艺条件稳定、可行,黄酮提取率较高。聚酰胺树脂纯化的工艺条件简便,效果良好。 相似文献
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目的 优化恩施巴戟中主要环烯醚萜苷类成分提取工艺,评价恩施巴戟体外抗氧化活性。方法 选择经典的加热回流提取法,以乙醇体积分数、溶剂倍量、提取时间为考察因素,以浸膏得率和水晶兰苷含量的综合评分为评判指标,设计正交试验筛选最佳提取工艺条件;测定总还原能力、DPPH清除率、羟自由基清除率,检测其体外抗氧化活性。结果 最佳提取工艺条件为6倍量的60%的乙醇加热回流2 h;恩施巴戟具有一定的抗氧化能力,乙酸乙酯部位活性最佳。结论 优化的提取工艺稳定可行,可用于提取恩施巴戟的环烯醚萜苷类成分,该研究初步证明了恩施巴戟具有一定的抗氧化活性。 相似文献
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目的 确定土圞儿中总生物碱最佳的提取、纯化条件,为其开发和利用提供科学的理论依据。方法 采用L9(34)正交试验,加酸水加热回流提取,考察溶剂用量、提取时间、提取次数3个因素对土圞儿中总生物碱得率的影响。结合静态和动态吸附实验,分别比较了6种不同型号的大孔树脂(D101,H-30,LSD-001,HPD450,DM130,AB-8)对土圞儿总生物碱的吸附和解吸性能,并以吸附量、洗脱量为考察指标,对大孔树脂纯化总生物碱的条件进行了筛选。以盐酸小檗碱为对照品,采用紫外分光光度法测定土圞儿总生物碱的含量。结果 土圞儿中总生物碱的最佳提取工艺条件为15倍量酸水加热回流提取2次,每次1 h。HPD450型树脂具有最佳的吸附及洗脱参数,其最佳纯化条件:上样液总生物碱浓度为1.6 mg·mL-1,pH 8.0,先以5倍柱体积的水洗去杂质,再以4倍柱体积40%乙醇洗脱,最后用4倍柱体积90%乙醇洗脱,得总生物碱量是纯化前总生物碱量80%左右。结论 该提取、纯化条件简单可行,具有良好的应用前景。 相似文献
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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。 相似文献
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New 2,6-piperidinediones 2a–g and 4a–d were prepared by initial condensation of aromatic aldehydes or cycloalkanones with cyanoacetamide to give α-cyanocinnamides
la–g or cycloalkylidenes 3a,b which underwent Michae1 addition with ethyl cyanoacetate or diethylmalonate. Compounds 4a–d were alkylated by various alkyl halides to produce the N-alkylated 2,6-piperidinedione derivatives 5a–m.
Some new selected compounds 2a–c,f, 4a–d & 5e,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 2f. 相似文献
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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. 相似文献
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目的 探讨抗幽门螺杆菌(HP)活性挥发油的药效物质,初步预测潜在活性成分及其作用机制。方法 微量稀释法(96 微孔板)测定丁香、广藿香、紫苏、牛至、枳实、厚朴、薄荷、肉桂 8 种挥发油对 HP 的抑制率,筛选出抑菌活性最强的 3种挥发油。气相色谱-质谱法联用(GC-MS)分析 3 种挥发油的化学成分,利用 TCMSP、Swiss Target Prediction、PubChem数据库获取 3 种挥发油主要活性成分及其对应靶点信息;网络药理学技术预测其潜在活性成分、相关通路及关键靶点;AUTO DOCK Vina 软件对核心成分及关键靶点基因进行分子对接,初步验证潜在活性成分及关键靶点。结果 广藿香、牛至和肉桂挥发油抑制 90% 细菌生长的最低药物浓度(MIC90)分别为 0.250、0.250、0.125 μL·mL-1,具有较强的抑菌活性;从以上 3 种挥发油中分别鉴定出 27、26、15 个化学成分,共筛选出 15 个活性成分,涉及 232 个基因靶点,影响了与抑制 HP相关的癌症通路、化学致癌-受体激活及 EGFR 酪氨酸激酶抑制剂耐药性等 275 条信号通路;分子对接验证结果显示 3 种挥发油抗 HP 与 SRC 蛋白密切相关,15 个活性成分与关键靶点 SRC 的结合较为稳定。结论 广藿香、牛至、肉桂 3 种活性挥发油通过多成分、多靶点、多通路的形式发挥抗 HP 作用。 相似文献
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喙果黑面神化学成分研究 总被引:2,自引:0,他引:2
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。 相似文献
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Katia Soto-Liebe Alejandro A. Murillo Bernd Krock Karina Stucken Juan J. Fuentes-Valds Nicole Trefault Allan Cembella Mnica Vsquez 《Toxicon》2010,56(8):1350-1361
The toxigenic freshwater cyanobacterium Cylindrospermopsis raciborskii T3 has been used as a model to study and elucidate the biosynthetic pathway of tetrahydropurine neurotoxins associated with paralytic shellfish poisoning (PSP). There are nevertheless several inconsistencies and contradictions in the toxin profile of this strain as published by different research groups, and claimed to include carbamoyl (STX, NEO, GTX2/3), decarbamoyl (dcSTX), and N-sulfocarbamoyl (C1/2, B1) derivatives. Our analysis of the complete genome of another PSP toxin-producing cyanobacterium, Raphidiopsis brookii D9, which is closely related to C. raciborskii T3, resolved many issues regarding the correlation between biosynthetic pathways, corresponding genes and the T3 toxin profile. The putative sxt gene cluster in R. brookii D9 has a high synteny with the T3 sxt cluster, with 100% nucleotide identity among the shared genes. We also compared the PSP toxin profile of the strains by liquid chromatography coupled to mass spectrometry (LC-MS/MS). In contrast to published reports, our reassessment of the PSP toxin profile of T3 confirmed production of only STX, NEO and dcNEO. We gained significant insights via correlation between specific sxt genes and their role in PSP toxin synthesis in both D9 and T3 strains. In particular, analysis of sulfotransferase functions for SxtN (N-sulfotransferase) and SxtSUL (O-sulfotransferase) enzymes allowed us to propose an extension of the PSP toxin biosynthetic pathway from STX to the production of the derivatives GTX2/3, C1/2 and B1. This is a significantly revised view of the genetic mechanisms underlying synthesis of sulfated and sulfonated STX analogues in toxigenic cyanobacteria. 相似文献
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银杏叶提取物与刺梨配伍抗实验性肝损伤作用 总被引:4,自引:0,他引:4
目的:比较复方银杏叶胶囊(CGB)与单方银杏叶提取物(GBE)的保肝作用。方法:用CGB、GBE给小鼠灌胃30d后,腹腔注射CCl4诱发肝损伤,测定小鼠血清丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)及肝匀浆超氧化物歧化酶(SOD)、丙二醛(MDA)含量;用H2O2诱导人肝L-02细胞氧化损伤,观察细胞增殖及总抗氧化能力。结果:CGB2.4、0.8和0.4g/kg3个剂量组与模型组比较,小鼠血清ALT、AST明显降低(P〈0.01,P〈0.05),同时肝匀浆中SOD显著升高、MDA下降(P〈0.01,P〈0.05);CGB组细胞增殖率和总抗氧化能力分别较模型组和单方组显著提高(P〈0.05、P〈0.01)。结论:CGB的抗肝损伤作用优于单方银杏叶提取物。 相似文献
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Futagami S Suzuki K Hiratsuka T Shindo T Hamamoto T Ueki N Kusunoki M Miyake K Gudis K Tsukui T Sakamoto C 《Inflammopharmacology》2007,15(1):1-4
COX (cyclooxygenase) is one of the key enzymes involved in the synthesis of a variety of prostaglandins (PGs), some of which
have been strongly linked to inflammation. One of its two well-known isoforms, COX-2, is an inducible enzyme whose induction
and expression is dynamically regulated by growth factors, mitogens, and tumor promoters.
Several animal and clinical studies have reported the chemopreventive effect of celecoxib, a selective COX-2 inhibitor; and
in particular, a few studies have shown that celecoxib prevents the development of gastric cancer. Administration of celecoxib
also showed increases in cardiovascular risk and disruption of renal physiology. Therefore, studies hoping to clarify how
selective COX-2 inhibitors modulate gastric cancer must keep in mind that coxibs have also been linked to serious cardiovascular
events and disruption of renal physiology.
Received 12 July 2006; accepted 21 August 2006 相似文献
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目的 分析克拉玛依市中心医院2017—2020年住院患者常见分离菌分布及耐药率的变迁情况,为指导抗菌药物临床合理应用提供依据。方法 收集2017—2020年克拉玛依市中心医院住院患者抗菌药物使用情况及分离菌,分析主要分离菌对常见抗菌药物的耐药率变化趋势。结果 2017—2019克拉玛依市中心医院抗菌药物使用率和使用强度呈下降趋势,4年共有分离菌12 135株,其中革兰阳性菌2 567株,占21.15%;革兰阴性菌6 310株,占52.00%;真菌3 258株,占26.85%。居前5位的分离菌分别是白色假丝酵母菌(19.59%)、大肠埃希菌(16.84%)、肺炎克雷伯菌(13.33%)、鲍曼不动杆菌(8.71%)和铜绿假单胞菌(7.94%)。主要分离菌对常用抗菌药物耐药率总体呈下降趋势,肠杆菌科细菌对临床常用抗菌药物耐药性下降最明显。结论 克拉玛依市中心医院分离菌逐年增加,耐药率有下降趋势,抗菌药物临床应用基本合理,但需完善真菌检测能力。 相似文献