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     

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.     

平衡针法对局灶性脑缺血大鼠血清TNF-α、sICAM-1的影响及其相关性的分析

目的 :通过研究缺血性脑卒中大鼠针刺前后的血清TNF α、sICAM 1水平变化 ,探讨缺血性脑损伤机制及平衡针法在缺血性损伤中对脑的保护作用。方法 :将 60只大鼠随机分为空白组、假手术组、模型组、治疗组 ,光化学法诱导局灶性脑缺血模型 ,酶联法 (ELISA)测量血清TNF α、sICAM 1值。结果 :血清TNF α、sICAM 1水平模型组较空白组明显上升 (P <0 .0 0 1) ,平衡针治疗组较模型组有所降低 (P <0 .0 5) ,血清TNF α与sICAM 1呈正相关 (r=0 .83 4,P <0 .0 5)。结论 :局灶性脑缺血大鼠血清TNF α、sICAM 1含量明显上升 ,二者呈正相关。平衡针法治疗可降低其TNF α、sICAM 1水平 ,从一定程度上抑制缺血性脑损伤。     

荧光分光光度法检测裸鼠移植瘤组织中阿霉素浓度

目的建立裸鼠移植瘤组织中阿霉(Dox)素浓度的荧光分光光度法检测方法。方法建立KB、KBv200细胞裸鼠移植瘤模型,经鼠尾静脉给予不同剂量阿霉素,3h后,处死裸鼠,分离及匀浆肿瘤组织,用含0.3mol·L-1HCl的60%乙醇抽提,离心取上清液,用荧光分光光度计在λex/em为470/590nm测定其荧光值,通过标准曲线方程计算阿霉素浓度。结果样本扫描未见杂峰,日内精密度<6.4%,日间精密度小于5.7%,阿霉素于肿瘤组织匀浆中抽提回收率>75.9%,KB细胞移植瘤组织中阿霉素浓度为KBv200的2.53～4.54倍。结论本方法专属性高,快速、简便,结果准确可靠,适用于裸鼠移植瘤组织中Dox药代动力学研究。     

电喷雾离子化多级质谱对几种氨基糖苷类抗生素特征碎片的分析

应用电喷雾离子化多级质谱法分析几种含2-脱氧链霉胺的氨基糖苷类抗生索的碎片离子，并对它们的裂解规律进行分析归纳。除其它特征碎片离子峰外，所有测试样品的质谱图中都存在质荷比为163．1的归属于2-脱氧链霉胺的碎片离子峰。这些裂解规律可应用于微生物新药筛选中早期快速鉴别含2-脱氧链霉胺的氩基糖苷类抗生索，对氨基糖苷类抗生索的生产、质量监控以及在环境和食品中的微量检测也有指导意义。     

八味地黄汤各药味对附子生物碱影响的电喷雾质谱研究

目的以八味地黄汤为研究对象,考察各药味对附子生物碱的影响规律,揭示附子配伍组方的科学内涵,为科学阐释八味地黄汤配伍规律提供化学依据。方法利用电喷雾质谱技术分别对八味地黄汤,附子加山茱萸、山药、肉桂、丹皮、泽泻、地黄、茯苓共煎液以及次乌头碱加山茱萸、山药共煎液进行系统考察。结果次乌头碱加山药、山茱萸,附子加山药等共煎液中次乌头碱含量较高;八味地黄汤、附子加山茱萸共煎液中次乌头碱含量较低;肉桂、丹皮、泽泻、地黄、茯苓等对附子生物碱的影响不明显。结论八味地黄汤中乌头碱和中乌头碱水解和溶出比较完全,次乌头碱的含量较少,次乌头碱的减少是由于水解以及溶出受到抑制导致。其中山茱萸对制附子起减毒作用,其减毒机制主要是抑制了制附子中次乌头碱的溶出。而山药则能导致附子毒性增加。     

气相色谱-质谱联用法分析角叉菜中的化学成分

为探讨角叉菜生物活性物质，分别采用氯仿：甲醇混合溶剂和乙醇以不同方式对角叉菜进行提取，用气相色谱-质谱联用仪分析了提取物的化学组成及其相对含量。     

扇贝裙边中糖胺聚糖的气相色谱定性定量分析及红外光谱分析

目的 对栉孔扇贝和海湾扇贝裙边中提取分离的糖胺聚糖进行化学组成及结构研究。方法 样品经盐酸—甲醇试剂醇解成单糖．采用标准对照法及内标法进行气相色谱定性定量测定。样品经KBr压片，红外光谱扫描(4000～500cm^-1)。结果 测定出栉孔扇贝糖胺聚糖中单糖含量分别为鼠李糖0．75％，木糖0．63％，岩藻糖0．67％，甘露糖0．97％，葡萄糖1．11％，半乳糖1．59％。红外光谱测定结果显示，栉孔扇贝和海湾扇贝糖胺聚糖具有典型酸性黏多糖的吸收特征。结论 从栉孔扇贝裙边中提取分离的糖胺聚糖，分子中含有中性糖基。与标准品的红外光谱进行比较．两种扇贝糖胺聚糖均与透明质酸的红外光谱相似。