Determinations of residual furazolidone and its metabolite, 3-amino-2-oxazolidinone (AOZ), in fish feeds by HPLC-UV and LC-MS/MS, respectively

The antibacterial drug furazolidone belonging to the group of nitrofuran antibacterial agents has been widely used as an antibacterial and antiprotozoal feed additive for poultry, cattle, and farmed fish in China. During application a large proportion of the administered drug may reach the environment directly or via feces. Although the use of furazolidone is prohibited in numerous countries, there are indications of its illegal use. It is known that furazolidone can be rapidly metabolized to 3-amino-2-oxazolidinone (AOZ) in the body of the target organism. In this study, a total of 21 fish feed samples, including 17 commercial fish feeds from local markets in China (representing 15 different formulations) and 4 fish feeds obtained from Germany and Turkey, respectively, are analyzed to determine whether the drug is still illegally used or commercially available feeds are contaminated by this drug. High-performance liquid chromatography (HPLC) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methods have been implemented to determine furazolidone and its metabolite AOZ in fish feeds containing animal protein, respectively. An efficient and convenient cleanup method for the determination of furazolidone in fish feeds is developed, and a simple cleanup method for the determination of AOZ is used. Method recoveries for samples used were determined as 87.7-98.3% for furazolidone at two spike levels of 2.0 and 5.0 ng g(-1) and as 95.6-102.8% for AOZ at spike levels of 0.4 and 0.8 ng g(-1). Limits of detections were 0.4 ng g(-1) for furazolidone and 0.05 ng g(-1) for AOZ. The established methods are therefore suitable for the determination of furazolidone and its metabolite AOZ in fish feeds at trace contamination levels. Using the established methods, all fish feed samples have been proved to be furazolidone negative; however, AOZ is tested in 16 of 17 fish feeds obtained from local markets in the Hubei province of China, with a positive rate as high as 94.1%.

Optimization of RP-HPLC analysis of low molecular weight organic acids in soil

RP-HPLC analysis for low molecular weight organic acids in soil solution has been optimized. An Atlantis (TM) C-18 column was used for the analyses. An optimal determination for eleven organic acids in soil solution was found at room temperature (25 degrees C) and 220 nm detection wavelength, with a mobile phase of 10 mM KH2PO4 -CH3OH (955, pH 2.7), a flow rate of 0.8 mL/min and 10 mu L sample size. The detection limits ranged 3.2-619 ng/mL, the coefficients of variation ranged 1.3-4.6%, and the recoveries ranged 95.6-106.3% for soil solution with standard addition on the optimal conditions proposed.

旋光性聚合物HPLC-CSP的制备及手性拆分能力的研究

手性是自然界的一种普遍现象，生命现象离不开手性。手性物质在有机化学、药物化学、生物化学以及功能材料等领域显示出诱人的应用前景。外消旋体的拆分是手性研究的重要基础工作。高效液相色谱手性固定相法（HPLC-CSP）在对映体化合物的分离分析和制备方面表现出独特的优势。本论文以旋光性联萘类聚合物和纤维素类衍生物涂敷的手性固定相进行分析级和半制备级色谱拆分，研究和探讨了它们对外消旋化合物的手性识别能力。1. 纤维素类聚合物的合成 将微晶纤维素与相应的酰氯或异氰酸酯反应获得四种纤维系类衍生物，纤维素三苯甲酸酯（CTB）、纤维素三苯基氨基甲酸酯（CTPC）、纤维素三（3,5-二甲基苯基氨基甲酸酯）（CDMPC）、纤维素三联萘甲酸酯（CTBPT）。红外、核磁、元素分析证明原料纤维素已酯化完全。2. 旋光性聚合物手性固定相及HPLC手性柱的制备采用聚合物涂敷硅胶方法制备了四种纤维素类、三种联萘聚酰胺手性固定相和二种半制备级纤维素手性固定相，匀浆法装柱。研究了不同的涂敷液对色谱柱效的影响。3. 旋光性联萘聚酰胺手性柱拆分能力的探讨 在三种由（S）-联萘聚酰胺涂敷的色谱柱上，以多种流动相体系对多种外消旋化合物进行手性折分试验。4. 纤维素类手性分析柱拆分能力的研究 对手性柱进行塔板数和稳定性测试及拆分能力研究。对一些外消旋化合物实现了手性拆分。由实验结果可以看出，以CDMPC涂敷的手性柱对多种外消旋化合（包括药物）具有手性拆分能力，具分离度较高。5. 半制备级拆分 对三种外消旋药物在纤维素半制备色谱柱上进行了半制备级拆分。我们在分析型色谱柱进行了流动相条件的选择，将优化后的分析条件直接放大到半制备色谱中，不仅节省了模索条件的时间，而且可以节省大量的流动相，预计一天内所能达到的对外消旋体最大拆分量可达克级以上。6. 进行了HPLC-UV-旋光仪的联用检测研究，实现了在线流动过程中旋光曲线的绘制。

唐古特瑞香和大果大戟的化学成分研究

本学位论文由两部分共3章组成。第一部分分别报道2种藏药唐古特瑞香和大果大戟化学成分的研究成果，从2种药用植物共分离鉴定了60个不同的化合物，其中12个为新结构，特别有意义的是发现了2个具有同一新骨架的二萜化合物。第二部分概述了大戟科植物多环二萜的研究进展。 第一部分包括第1和2章。在这2章中分别报道了唐古特瑞香（Daphne tangutica Maxim）和大果大戟（Euphorbia wallichii Hook. f. Fl）化学成分的分离纯化与结构鉴定。实验采用正、反相硅胶柱层析、薄层制备及HPLC等分离方法，从唐古特瑞香的根皮中共分离出32个化合物，通过红外、质谱及核磁共振等波谱方法鉴定了其中的31个，结构类型分别属于瑞香二萜类、木脂素类、香豆素类、苯丙素类及甾体类，其中有三个新的瑞香二萜型化合物，经波谱分析将它们的结构分别鉴定为1,2a-二氢-20-棕榈酰瑞香毒素、1,2a-二氢-5b-羟基-6a,7a-环氧-树脂大戟醇-14-苯甲酸酯及1,2b-二氢-5b-羟基-6a,7a-环氧-树脂大戟醇-14-苯甲酸酯，另外还有13个已知化合物为首次从该植物中分离得到。从大果大戟的根部共分离出33个化合物，鉴定了其中的30个，其主要成分为种类丰富的二萜，包括巨大戟烷型、续随子烷型、对映－阿替生烷型、对映－贝壳杉烷型、对映－松香烷型、ent-trachylobane型、对映－异海松烷型及一新骨架五环二萜ent-wallichane型，另外还有香豆素、甾体、三萜和一些简单的小分子化合物。其中新化合物有9个，经波谱分析将它们的结构分别鉴定为5-O-(2E,4E,6E)-癸三烯酰基-3,20-O-二乙酰基巨大戟醇、5-O-(2E,4Z)-癸二烯酰基-3-O-乙酰基-20-去氧巨大戟醇、3-O-(2E,4Z)-癸二烯酰基-5b,6b-氧-交京大戟醇、7-苯甲酰氧基-3,5,15-三乙酰基-续随子醇、ent-trachylobane-3-one-17-oic-acid、3α-羟基-对映-阿替斯-16-烯-14-酮、3α,6-二羟基-对映-异海松-7-烯-2,15-二酮、wallichanol A 和 wallichanol B，其中，wallichanol A 和 wallichanol B属于一新骨架类型的五环二萜。除此以外，另有13个已知化合物为首次从该植物中分离得到。 第2部分即第3章，首次概述了大戟属植物中多环二萜的化学和药理研究进展。 This dissertation is composed by two parts. The first part reports the phytochemical investigation of two Tibetan medicine plants, Daphne tangutica Maxim and Euphorbia wallichii Hook. f. Fl. Sixty different compounds including ten new compounds and two novel diterpenoids possessing a new carbon skeleton were isolated and identified. The second part is a review about the progress of studies on the polycyclic diterpeniods of the plant family of Euphorbia. The first part consists two chapters, which expatiate on the isolation and identification of chemical constituents from D. tangutica and E. wallichii. Thirty-one compounds were isolated from the root barks of D. tangutica by methods of column chromatography (silica gel, including reversed phase), preparative TLC and HPLC, and their structure were identified as nine daphnane diterpenes, six lignans, nine cumarin derivatives, five phenylpropanoid derivatives, a steroids and a benzoate on the basis of spectroscopic methods including IR, MS and NMR. Among them, three are new diterpenes with skeleton of daphnane and the structure were determined as 1,a-dihydro-20-palimoyl-daphnetoxin, 1,2a-dihydro-5b- hydroxy-6a,7a-epoxy-resiniferonol-14-benzoate and 1,2b-dihydro-5b-hydroxy- 6a,7a-epoxy-resiniferonol-14-benzoate. In addition, thirteen known ones were isolated from this plant for the first time. Isolation of the roots of E. wallichii yielded thirty compounds, twenty-four of them were elucidated as diterpenoids, which belong to different skeleton types of ingenol, lathyrane, ent-atisane, ent-kaurane, ent-abietane, ent-trachylobane, ent-isopimarane and a new pentacyclic skeleton ent-wallichane respectively. The remains including a cumarine, a triterpenoid, a steroid and three compounds with small molecule. Nine new compounds were characterized as 5-O-deca-2E,4E,6E- trienoyl-3,20-O-diacetylingenol, 5-O-deca-2E,4Z-dienoyl-3-O-acetyl-20- deoxyingenol, 3-O-deca-2E,4Z-dienoyl-jolkinol-5b,6b-oxide, 7-benzoyl-3,5,15- triacetyl-7-hydroxylathyrol, ent-trachylobane-3-one-17-oic-acid, 3α-hydroxy-ent- atis-16-en-14-one, 3α,6-dihydroxy-ent-isopimarane-7-en-2,15-dione, wallichanol A and wallichanol B, respectively, by means of comprehensive spectroscopic analysis. Among them, wallichanol A and wallichanol B were two notable novel pentacyclic diterpenoids processing a new rearranged carbon skeleton. And more, thirteen ones were firstly reported from this plant. The third chapter summarizes the research development on chemistry and pharmacology of polycyclic diterpenes from the plant family of Euphorbia for the first time.

中药射干的化学成分研究

本学位论文由4章组成。第一章是论文的主体，报道了中药射干的化学成分研究。第二章是中药射干代用品川射干的化学成分研究，并附带报道了西番莲化学成分的研究结果。第三章是射干、川射干及西番莲提取物化学成分串联质谱分析的报道。第四章为综述，概述了射干及鸢尾属植物的化学成分和药理研究进展。 在第一和二章中分别报道了射干（Belamcanda chinensis (L.) DC.）、川射干 （Iris tectorum Maxim.）及西番莲（Passiflora incarnate L.）化学成分的分离纯化与结构鉴定。采用正、反相硅胶柱层析、凝胶柱层析、薄层制备及HPLC等各种分离方法，从三种药用植物中共分离出68个不同的化合物，其中61个的结构得 得以鉴定，另外4个化合物的结构正在鉴定中，3个由于量少且有点杂质未作进一步的鉴定。 中药射干（Rhizoma Belamcandae）为射干植物的干燥根茎，从中共分离出53个化合物，通过红外、质谱及核磁共振等波谱方法鉴定了包括12个新化合物在内的48个，结构类型分别属于iridal型三萜及其新颖的二聚体、异黄酮、黄酮及黄酮醇、香豆素、甾体、芳香酸和脂肪酸及其甘油酯等。新化合物中有两个异黄酮类化合物，其结构分别鉴定为5,7,8,4′-四羟基-6-甲氧基异黄酮和5,6-二羟基-4′-甲氧基异黄酮-7-O-β-D-吡喃葡萄糖苷；八个新的iridal型三萜化合物分别鉴定为鸢尾烯（L）、16-甲氧基鸢尾烯、16-去羟基鸢尾烯、2-(E)-16-去羟基鸢尾烯、16-去羟基鸢尾烯B、3-乙酰基-16-去羟基鸢尾烯、iristectoroneL和iristectoroneM；两个结构骨架新颖的双三萜，分别命名为射干素A和射干素B，其分离纯化的困难以及结构的新颖和复杂突显出该论文的科学意义。除这些新化合物外，还有9个已知化合物为首次从中药射干中分离得到。此外，从中药射干的代用品川射干中分离得到7个已知化合物，主要是黄酮类成分及iridal型三萜化合物，其中1个三萜化合物为从射干中分离鉴定的新成分。另外还从西番莲中分离出8个化合物，鉴定了其中的6个，主要为黄酮碳苷。 第三章是关于射干、川射干及西番莲提取物化学成分的ESI-MS-MS分析，在初步探讨了从这些植物中分离鉴定出的一些异黄酮及黄酮碳苷的质谱裂解规律基础上，通过质谱和串联质谱分析，定性和半定量地检测了射干和川射干中主要的异黄酮成分以及西番莲中的黄酮碳苷成分，为这些药材品质的快速鉴定提供了一种简便方法。 第四章概述了射干及鸢尾属药用植物的化学和药理研究进展，特别是对其中异黄酮及三萜类成分的研究进展进行了深入系统的综述。 This dissertation is composed by four chapters. The first and second chapter reports the phytochemical investigation of three medicine plants, Belamcanda chinensis (L.)DC., Iris tectorum Maxim. and Passiflora incarnate L. Sixty eight different compounds were isolated and sixty one of them were identified. The third chapter described rapid ESI-MS-MS analysis of B. chinensis, I. tectorum, and P. incarnate. The forth part is a review about the progress of studies on the chemical constituents from Belamcanda chinensis and Iris species. Fifty-three compounds were isolated from Rhizoma Belamcandae, the rhizomes of B. chinensis by the methods of column chromatography (normal and reversed phase silica gel, Sephadex LH-20), preparative TLC and HPLC. On the basis of spectroscopic methods including IR, ESI-MS, 1-D and 2-D NMR, forty eight of them were identified as seventeen flavonoids, seventeen tritepenoids, one cumarin, five steroids and some benzene derivative etc. Among them, the structures of twelve new compounds were elucidated as 6-methoxy-5,7,8,4′-tetrahydryoxyisoflavoe, 4′-methoxy-5,6-dihydroxyisoflavone-7-O-β-D-glucopyranoside, iristectorene L, 16-methoxyisoiridogermanal, 16-dehydroxyisoiridogermanal, 2-(E)-16-dehydroxy isoiridogermanal, 16-dehydroxyiristectorene B, 3-acetyl-16-dehydroxyisoiridoger- manal, iristectorone L, iristectorone M, belamcandene A and belamcandene B. Last two new compounds are dimer of triterpenoids with a novel carbon skeleton. Beside the new compounds, nine known ones were isolated from this plant for the first time. Isolation of I. tectorum yielded seven compounds. On the basis of spectroscopic methods including ESI-MS, NMR and the comparison with authentic samples, three of them were determined as isoflavone, two of them were triterpenoids, and other two were β-sitosterol and apocynin. All of them are known compounds except one of iridal type triterpenoid, 16-dehydroxyiristectorene B, which also obtained from B. chinensis as a new compound. Isolation of P. incarnate yielded eight compounds. Six of them were determined on the basis of spectroscopic methods including ESI-MS, NMR and the comparison with authentic samples. Four of them are flavone-C-gluconside, and two are steroids. The third chapter describes the tandem mass spectrometry (ESI-MS-MS) analysis of the isoflavonoids from B. chinensis and I. tectorum, as well as C-glycosyl-flavonoide from P. incarnate, in order to explore the rapid methodology of validating the quality of the herbs. In addition, the fractionation rules of some iosflavonoids and C-glycosyl-flavonoids were discussed. The fourth chapter summarizes the research development on chemistry and pharmacology of medicine plants of B.chinensis and Iris species.

HPLC与MALDI-TOFMS联用技术分析蛋黄中的磷脂

蛋黄中含有大量磷脂,其中磷脂酰胆碱(PC)和磷脂酰乙醇胺(PE)最为丰富。本研究采用高效液相色谱法(HPLC)与基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)联用技术分析了蛋黄中磷脂粗提物。将从蛋黄中提取的多种磷脂通过HPLC预先分离,收集各组分后分别进行MALDI-TOF MS分析得到比较清晰的质谱图。通过质谱图解析确定了蛋黄中磷脂酰胆碱、神经鞘磷脂(SM)的脂肪酸组成。