乌头碱类生物碱的质谱研究进展

本文简述质谱方法在乌头碱型 C19二萜生物碱的分析和结构鉴定等方面的应用以及不同电离方式下乌头碱的断裂行为 ,并总结我们近来利用电喷雾串联质谱技术分析几种乌头属植物中生物碱的研究结果 ,提出脂类生物碱 ( lipo-alkaloids)存在于其它乌头属植物中的可能性

Hymeniacidon perleve associated bioactive bacterium Pseudomonas sp NJ6-3-1

Among marine bacteria isolated from the cytotoxic sponge Hymeniacidon perleve, one strain NJ6-3-1 classified as Pseudomonas sp. showed both cytotoxic and antimicrobial activities. Fatty acid analysis indicated that the bacterial strain consists mainly of C16:1, C16:0, C18:1, C18:0, C15:0, C14:0. One unusual 9,10-cyclopropane-C17:0 fatty acid and C26:0 also constitute major components, as well as the existence of squalene, the precursor of triterpenoids. The major metabolites in the culture broth were identified as alkaloids, including diketopiperazines and indole compounds, namely 3,6-diisopropylpiperazine-2,5-dione, 3-benzyl-3-isopropylpiperazine-2,5-dione, 3,6-bis-(2-methylpropyl)-piperazine-2,5-dione, indole-3-carboxaldehyde, indole-3-carboxylic acid methyl ester, indole-3-ethanol, and quinazoline-2,4-dione.

Two new bromoindoles from red alga Laurencia similis

Two new bromoindole alkaloids have been isolated from the ethanolic extract of the red alga Laurencia similis. On the basis of chemical and spectroscopic methods (including 1D and 2D NMR technique), their structures have been elucidated as 2,2',5,5',6,6'-sixibromo-3, 3'-bi-1H-indole and 3, 5-dibromo-1-methylindole, respectively. (C) 2008 Xiao Bin Zhu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

两种虎皮楠属植物中生物碱成分研究

运用地球化学研究领域常用的多种分离材料和分离手段，并结合相关的现代波谱分析技术，从两种虎皮楠属植物的五个不同部位中共分离鉴定了58个生物碱成分（有48个不同结构的化合物），其中含有16个新的生物碱。已鉴定的生物碱结构类型涉及Daphnane型、Secodaphnane 型、Yuzurimine型、 Daphnilactone型、Yuzurine型、Calycipyylline A型、Calyciphylline B型、Daphmanidin A型、Daphnicyclidin型和Paxdaphnine A型虎皮楠生物碱及Quinolizidine型生物碱等。首次在植物虎皮楠中发现苦参碱类生物碱。 第一章为虎皮楠属植物虎皮楠中生物碱成分的研究。本章内容分为三节： 第一节为虎皮楠枝叶中生物碱成分的研究。从虎皮楠枝叶的乙醇提取物中的总碱部分分离鉴定了21个生物碱，其中新虎皮楠生物碱5个。 第二节为虎皮楠根中生物碱成分的研究。从虎皮楠根部的乙醇提取物的总碱部分分离鉴定了17个生物碱，其中有5个新虎皮楠生物碱均为Secodaphnane型生物碱。 第三节为虎皮楠果实中生物碱成分的研究。从虎皮楠果实的乙醇提取物的总碱部分分离鉴定了共10个生物碱，包括2个新虎皮楠生物碱（1–2），分别属于Daphnilongerine型和Yuzurine型生物碱。 第二章为虎皮楠属植物显脉虎皮楠中生物碱成分的研究。从显脉虎皮楠的枝叶和果实的乙醇提取物中的总碱部分分离鉴定了10个生物碱（其中4个为新虎皮楠生物碱）。 第三章为综述部分。总结了自2003年至2007年4月以来，虎皮楠生物碱研究的新进展。

Preparation of monolithic silica column with strong cation-exchange stationary phase for capillary electrochromatography

A monolithic silica based strong cation-exchange stationary phase was successfully prepared for capillary electrochromatography. The monolithic silica matrix from a sol-gel process was chemically modified by treatment with 3-mercaptopropyltrimethoxysilane followed by a chemical oxidation procedure to produce the desired function. The strong cation-exchange stationary phase was characterized by its substantial and stable electroosmotic flow (EOF), and it was observed that the EOF value of the prepared column remained almost unchanged at different buffer pH values and slowly decreased with increasing phosphate concentration in the mobile phase. The monolithic silica column with strong cation-exchange stationary phase has been successfully employed in the electrochromatographic separation of beta-blockers and alkaloids extracted from traditional Chinese medicines (TCMs). The column efficiencies for the tested beta-blockers varied from 210,000 to 340,000 plates/m. A peak compression effect was observed for atenolol with the mobile phase having a low phosphate concentration.

Electrochromatographic evaluation of a silica monolith capillary column for separation of basic pharmaceuticals

A silica-based monolithic capillary column was prepared via a sol-gel process. The continuous skeleton and large through-pore structure were characterized by scanning electron microscopy (SEM). The native silica monolith has been successfully employed in the electrochromatographic separation of beta-blockers and alkaloids extracted from traditional Chinese medicines (TCMs). Column efficiencies greater than 250000 plates/m for capillary electrochromatography (CEC) separation of basic compounds were obtained. It was observed that retention of basic pharmaceuticals on the silica monolith was mainly contributed by a cation-exchange mechanism. Other retention mechanisms including reversed-phase and normal-phase mechanisms and electrophoresis of basic compounds also played a role in separation. A comparison of the differences between CEC and capillary zone electrophoresis (CZE) separation was also discussed.