穿龙薯芋中两种水难溶性甾体皂甙的结构研究

中国科学院成都生物研究所等单位用四川汶川,茂汶产的穿龙薯芋根茎为原料,研制成治疗冠心病,抗动脉粥样硬化的药——“穿龙冠心宁”,经鉴定有一定疗效。我们从“穿龙冠心宁”的原料穿龙薯芋(Dioscorea nipponica Makino)中提取出两种水难溶组分:其一为无色针状晶体,熔点275.5～280℃(分解),[α]_D~(21)-118°(C=0.39吡啶),易溶于吡啶,氯仿一甲醇(3:1)混合液和热甲醇,稍溶于氯仿,微溶于乙醇,不溶于水,命名为Da;其二亦为无色针状晶体,熔点293～295℃(分解),[α]_D~(21)-81°(C=0.31吡啶),易溶于吡啶,热正丁醇—乙醇—水(3:1:1)混合液,可溶于甲醇,微溶于乙醇,不溶于水,命名为Db。Da、Db与水溶性成分共存时,则具有较大的水溶性。     

用AMD技术和TLC ESI-MS离线联用技术分析四物汤中的糖类成分

目的:对具有补血活性的四物汤提取物C薄层色谱(TLC)中的糖类斑点进行定性分析。方法:用自动多次展开(AMD)方法获得了四物汤提取物C的TLC图谱,用TLC与电喷雾离子化质谱(ESI-MS)离线联用技术对其中4个主要斑点进行分析,并且用AMD技术对其中的单糖进行了分析。结果:4个斑点的构成物质分别主要为单糖、二糖、三糖、四糖,其中单糖主要由葡萄糖和果糖组成。结论:TLC ESI-MS离线联用方法能快速简便地对中药TLC图谱中糖类斑点进行定性。AMD单糖分析方法可实现在普通10 cm硅胶板上8种常见单糖的良好分离,并且展开过程自动化。AMD和TLC ESI-MS离线联用技术对糖类成分分析具有良好的应用价值。     

CLINICO-PATHOLOGIC CONFERENCE: 12-YEAR-OLD GIRL WITH FATIGUE, ANEMIA, WEIGHT LOSS, ABDOMINAL DISTENTION, AND OCCASIONAL NAUSEA AND VOMITING

A clinicopathologic case is presented. The patient was a 12-year-old white girl with a history of fatigue and dizziness, occasional nausea and vomiting, and anemia, who showed abdominal distention, especially in the epigastrium. An epigastric mass was palpable. Gastroscopy was done, and surgery followed. Pertinent laboratory findings are presented, and clinical discussion follows. The pathology is then presented and discussed.     

复方氯霉素凝胶的研制及质量控制

目的：制备复方氯霉素凝胶剂。方法：以氯霉素、己烯雌酚、硫酸锌为主药，卡泊姆为凝胶基质，制备复方氯霉素凝胶。用导数光谱法控制主药氯霉素的含量。结果：氯霉素的平均回收率为100．74％，RSD为0．29％。结论：该凝胶剂制备工艺简单，凝胶性质稳定，质量可控，可满足临床需求。     

天麻中硒的流动注射-氢化物发生-原子吸收光谱测定方法研究

目的　探讨原子化器温度、载气流速、KBH4 浓度等条件 ,对流动注射 氢化物发生 原子吸收光谱法 (FI HG AAS)测定硒时的影响。建立了FI HG AAS测定新鲜天麻中硒的分析方法。方法　流动注射 氢化物发生 原子吸收光谱法。结果　在优化的工作条件下 ,测定硒的最低检测浓度为 0 2 8μg·L- 1 ,线性范围为 0～ 50 μg·L- 1 ,相对标准偏差小于 5 % ,加样回收率为 96 %～ 1 0 4 % ,应用于新鲜天麻、富硒新鲜天麻中微量硒的测定 ,结果满意。结论　本法克服了传统的间断氢化物发生 原子吸收光谱法分析速度慢、样品耗量大、操作繁琐 ,且因手工进样在进样速度和进样体积上容易带来误差等缺点。方法操作简便、快速 ,灵敏度及自动化程度高     

Implication of brevetoxin B1 and PbTx-3 in neurotoxic shellfish poisoning in New Zealand by isolation and quantitative determination with liquid chromatography-tandem mass spectrometry.

Brevetoxin B1 (BTX-B1) was isolated from Austrovenus stutchburyi following the 1992-1993 outbreak of neurotoxic shellfish poisoning (NSP) in New Zealand. We report here the first isolation of PbTx-3 from the same shellfish and the development of a procedure for quantitative determination of PbTx-3 and BTX-B1. PbTx-3 was isolated by chromatography on columns of SiO2, ODS, and LH-20, followed by reverse-phase HPLCs. In mass spectrometry (MS) with an electrospray ionization (ESI) interface operating in the positive or negative ion mode, the abundant protonated ion [M+H]+ of PbTx-3 (m/z 897) and the de-sodiated ion [M-Na]- of BTX-B1 (m/z 1016) were generated, respectively. These served as precursor ions for collision-induced dissociation, and the product ions of m/z 725 from PbTx-3 and m/z 80 from BTX-B1 were identified, allowing unambiguous confirmation of these toxins by selected reaction monitoring liquid chromatography-tandem mass spectrometry (SRM LC-MS/MS) analysis. The determination limits were 0.4 and 2 ng/g for BTX-B1 and PbTx-3 at a signal-to-noise ratio of five, respectively. This LC-MS/MS method was successfully applied to determine BTX-B1 and PbTx-3 in the NSP-associated toxic shellfish. BTX-B1 was found in both A. stutchburyi and Perna canaliculus, but not in Crassostrea gigas, while PbTx-3 was found in all three.     

Utility of peptide–protein affinity complexes in proteomics: identification of interaction partners of a tumor suppressor peptide*

Abstract: We used a N‐biotinylated peptide analog of the C‐terminal domain of the tumor suppressor protein, p21^cip1/waf1 to elucidate peptide/protein interacting partners. The C‐terminal domain of p21^cip1/waf1 protein spanning 141–160 amino acid residues is known to bind PCNA and this interaction is important in many biological processes including cell‐cycle control. This C‐terminal 20‐mer efficiently extracts PCNA in the presence of a variety of N‐ or C‐terminally attached affinity tags. Using difference silver stained 2D gels combined with in‐gel tryptic digests, we identified the difference spots using MALDI‐TOF mass spectrometry‐based peptide mass fingerprinting followed by a database search using profound against NCBIs human nonredundant protein sequence data bank. Identified spots include the p48 subunit of chromatin assembly factor‐1, the heat shock 70 protein analog BiP, calmodulin, nucleolin and a spot similar in size to dimeric PCNA. In contrast, microcapillary ion‐trap LC‐MS/MS analysis of a tryptic digest of entire affinity extracts derived from both control and experimental runs followed by database searches using sequest confirmed the presence of most of the above proteins. This strategy also identified hnRNPA1, HPSP90α, HSP40 and T‐complex protein 1, a protein similar to prothymosin, and a possible allelic variant of the p21^cip1/waf1 protein. The use of N‐biotinylated peptide derived from the C‐terminal domain of p21^cip1/waf1 protein in proteomic analysis exemplified here suggests that peptides obtained from intracellular functional screens could also potentially serve as efficient baits to discover new drug targets.     

抗流感滴鼻剂不同除杂工艺微量元素的含量分析

目的：探讨不同除杂方法对微量元素含量的影响。方法：采用原子荧光法和电感耦合等离子体发射光谱法测定不同除杂方法所得澄清液中As，Hg，Pb，Fe，Mn，Zn，Cu的含量。结果：与原液比较，絮凝澄清液中As，Hg，Pb的去除率分别为57．1％，50．0％，39．6％，并分别为醇沉澄清液去除率的2．00，1．50，1．12倍；絮凝澄清液中的Fe，Mn，Zn，Cu保留率分别为90．6％，95．6％，91．7％，93．9％，并分别为醇沉澄清液保留率的1．09，1．29，1．15，1．28倍。结论：从有害元素的去除率及有益元素的保留率来看，絮沉工艺优于醇沉工艺。     

Synthesis and physico‐chemical properties of peptides in soil humic substances

Abstract: Soil humic substances (HS) are heterologous, polydispersive, and multi‐functional organometallic macromolecules ubiquitous in soils and sediments. They are key players in the maintenance of the belowground ecosystems and in the bioavailability of both organic and inorganic contaminants. It is widely assumed that the peptidic substructures of HS are readily degraded and therefore do not contribute significantly to interactions with contaminants such as toxic metals. To investigate the turnover of humified peptides, laboratory soil aging experiments were conducted with ¹³C‐glucose or ¹⁵N‐nitrate for 8.5 months. Evidence for random‐coil peptidic structures in the labeled HS was obtained from 2‐D nuclear magnetic resonance (NMR), pyrolysis gas chromatography‐mass spectrometry (pyro‐GC‐MS), and circular dichroism data. Interaction of metals with the peptidic carbonyls of labeled HS was rationalized from the solid‐state NMR data. Detailed ¹³C and ¹⁵N labeling patterns of amino acid residues in the acid hydrolysates of HS acquired from NMR and GC‐MS revealed two pools of peptides, i.e. one extant (unlabeled) and the other, newly humified with little isotopic scrambling (fully labeled). The persistence of pre‐existing peptidic structures indicates their resistance to degradation while the presence of fully labeled peptidic amino acids suggests wholesale incorporation of newly synthesized peptides into HS. These findings are contrary to the general notion that humified peptides are readily degraded.     

HPLC-MS法测定犬血浆中环维黄杨星D浓度及其药代动力学研究

目的 :建立用于测定环维黄杨星D血药浓度的液相色谱 质谱联用分析方法 ,并探讨环维黄杨星D在犬体内的药代动力学。方法 :犬 5只ig环维黄杨星D 10mg·kg-1后采集一系列血样 ,利用HPLC MS(TOF)法 ,测定血浆药物浓度 ,并用 3p97软件拟合求算药代动力学参数。结果 :环维黄杨星D浓度在 0 5～ 2 0 0ng·ml-1线性关系良好 (r=0 9999)。提取回收率高于 80 % ,日内、日间RSD均小于 15 % ,符合生物样品分析要求。 5只犬ig环维黄杨星D 10mg·kg-1后的血药浓度 时间曲线呈二室模型 ,其吸收相、分布相和末端消除相的半衰期 (t1/ 2Ka、t1/ 2α和t1/ 2 β)分别为 1 72 ,2 82 ,14 90h ,曲线下面积 (AUC)为 1372 5± 2 19 4ng·h·ml-1。结论 :建立的HPLC MS联用方法专属性强 ,灵敏度高 ,可用于环维黄杨星D的体内定量分析。