鸟嘌呤核苷-3′,5′-环磷酸衍生物的合成及生物活性研究

本文报道用三价磷试剂与保护的鸟嘌呤核苷反应,经碘氧化生成鸟嘌呤核苷-3′,5′-环磷酸酯和磷酰胺,并对它们的生物活性做了初步研究,N~2-二甲胺基甲烯基-2′-叔丁基二甲基硅基鸟嘌呤核苷-3′,5′-环磷酸酯和磷酰胺对小鼠肝癌腹水细胞的DNA和RNA合成有一定的抑制作用。N~2-二甲胺基甲烯基鸟嘌呤核苷-3′,5′’-环磷酸丁酯的两个磷原子构型不同的异构体可激活腺苷酸环化酶,使大鼠成骨肉瘸细胞株ROS 17/2.8的cAMP水平增高。     

鸟嘌呤核苷-3′,5′-环磷酸衍生物的合成及生物活性研究

本文报道用三价磷试剂与保护的鸟嘌呤核苷反应,经碘氧化生成鸟嘌呤核苷-3′,5′-环磷酸酯和磷酰胺,并对它们的生物活性做了初步研究,N²-二甲胺基甲烯基-2′-叔丁基二甲基硅基鸟嘌呤核苷-3′,5′-环磷酸酯和磷酰胺对小鼠肝癌腹水细胞的DNA和RNA合成有一定的抑制作用。N²-二甲胺基甲烯基鸟嘌呤核苷-3′,5′’-环磷酸丁酯的两个磷原子构型不同的异构体可激活腺苷酸环化酶,使大鼠成骨肉瘸细胞株ROS 17/2.8的cAMP水平增高。     

二氢吲哚类化合物的合成及其抑酶活性

本文报道了一系列二氢吲哚衍生物的合成,并测定其抑制胆碱酯酶活性,发现二氢吲哚环被二氢吲哚酮结构所取代,3位季碳被仲碳原子所取代,5位以可能有抑制酶活性的环磷酰基或磺酰基代替二甲氨甲酰基,均使抑酶活性几乎完全消失。在合成过程中,使1位N-烃化或5位O-酰化选择性地进行。     

二氢罂粟碱的酰胺化环合工艺改进

二氢罂粟碱是合成盐酸罂粟碱的主要中间体。制备工艺是用高藜芦酸和高藜芦胺在十氢萘中反应生成相应的酰胺,然后在三氯乙烯中环合而成。这两步反应存在着操作繁琐、周期长,并耗用大量有机溶媒等缺点。我们根据文献的报道,采用先使高藜芦酸及高藜芦胺在高温下直接酰胺化,不经分离,再加三氯乙烯和三氯氧磷环合的方法来合成。实验部分将高藜芦酸65 g(0.33 mol)及高藜芦胺     

马蔺子甲素全合成工艺的研究

以邻丁香酚为原料，经苄基保护酚羟基、臭氧制备醛、缩合、加氢还原并脱苄基保护基、硅烷保护酚羟基、缩合、脱保护基、催化氧化八步反应合成了马蔺子甲素。使反应的成本比原路线有了很大的降低。总收率也有了一定的提高。     

抗肿瘤药曲磷胺的合成工艺改进

目的对曲磷胺的合成工艺改进。使之适合工业化生产。方法以二乙醇胺、乙醇胺和3-氧丙醇为起姑原料经磷酰氯化、环磷酰胺化等关键步骤合成曲磷胺。结果与结论合成经工艺改进。多步收率有较大提高．总收率为41％。     

新霉胺类似物的合成与RNA结合和生物活性评价

为了提高新霉胺对16S rRNA的亲和力，合成了Ⅱ环5位修饰的新霉胺类似物。以新霉素B为原料，经水解，保护，亲核取代，脱保护，叠氮还原多步反应得到氨基或氨基链修饰的新霉胺类似物。用表面等离子共振法测定了所合成的化合物与大肠杆菌（E.coli．）核糖体A位点rRNA（16S RNA）的相互作用。合成了6个Ⅱ环5-位修饰的新霉胺类似物，发现Ⅱ环5位氨基链修饰可以增强化合物对16S RNA的亲和力，其中一些化合物在10^-3M有体外细菌抑制活性。在新霉胺的Ⅱ环5位引入氨基或脂肪胺可以增加与16S RNA的亲和力。Ⅱ环5位上羟基的构型改变对于药物／16S RNA复合物稳定性的影响较低。     

美托洛尔有关物质E和J的合成

目的为更好地对美托洛尔的产品质量进行控制,合成美托洛尔有关物质E和J。方法以2-羟基苯乙酸为起始原料,经过羧基还原、酚羟基保护、甲基化、酚羟基脱保护,再依次与环氧氯丙烷、异丙胺反应得到1-异丙胺基-3-[2-(2-甲氧乙基)苯氧基]-2-丙醇(E),总收率为49%。以4-(2-甲氧乙基)苯酚为起始原料,与环氧氯丙烷、丙烯醇反应后得到1-烯丙氧基-3-[4-(2-甲氧基乙基)苯氧基]-2-丙醇,再经环氧化、异丙胺化反应制得1-(2-羟基-3-异丙胺基)丙氧基-3-[4-(2-甲氧乙基)苯氧基]-2-丙醇(J),总收率为53%。结果与结论美托洛尔合成中的两个相关物质E、J的结构经核磁共振氢谱、质谱确证。两种合成路线原料易得、操作简便、条件温和、收率高,可为美托洛尔的质量评价和相关杂质的控制提供帮助。     

人尿中氢可酮及其代谢物的检测研究

用气相色谱 质谱联用仪(GC/MSD)检测人尿中氢可酮及其代谢物双氢吗啡。尿样经酸解、乙醚/异丙醇提取后,用甲氧胺吡啶液将羰基保护生成肟,再用MSTFA-MBTFA及MSTFA-TMSI衍生化后,经GC/MS分析,形成各自的特征图谱。方法灵敏、准确,可快速鉴别氢可酮、可待因、双氢可待因等结构相似药物。     

抗病毒性肝炎药——斑蝥素制剂

近年来,我国对斑蝥体内抗癌有效成分的研究证明:斑蝥素可直接作用于癌细胞,使其受到损害而显示抗癌作用。并已将从斑蛰提取的斑蝥素合成毒性小和疗效高的羟基斑蝥胺、斑蝥酸钠、甲基斑蝥胺作为抗癌化     

DNA adducts of acrolein: site-specific synthesis of an oligodeoxynucleotide containing 6-hydroxy-5,6,7,8-tetrahydropyrimido[1,2-a]purin-10(3H)-one,an acrolein adduct of guanine

3-(2-Deoxy-beta-D-erythro-pentofuranosyl)-6-hydroxy-5,6,7,8-tetrahydropyrimido[1,2-a]purin-10(3H)-one is formed in low yield by the reaction of acrolein with 2'-deoxyguanosine. The nucleoside and an oligodeoxynucleotide containing it have been synthesized. For preparation of the nucleoside 2'-deoxyguanosine was alkylated at the N1 position using 1-bromo-3-butene to give 1-(3-butenyl)-2'-deoxyguanosine. Oxidation with OsO(4) and N-methylmorpholine-N-oxide to give the 3,4-dihydroxybutyl adduct followed by oxidation with NaIO(4) gave the 1-(3-oxopropyl) adduct which cyclized spontaneously to yield the title compound as a rapidly epimerizing mixture of two diastereomers. Reduction of the nucleoside with NaBH(4) gave the unfunctionalized compound plus 1-(3-hydroxypropyl)-2'-deoxyguanosine showing that epimerization was occurring via both the imine and the 1-(3-oxopropyl) adduct. Reduction with NaCNBH(3) gave exclusively unfunctionalized 3-(2-deoxy-beta-D-erythro-pentofuranosyl)-5,6,7,8-tetrahydropyrimido[1,2-a]purin-10(3H)-one. The phosphoramidite reagent needed for preparation of oligonucleotides was prepared from 1-(3-butenyl)-2'-deoxyguanosine by glycolation after protection of the 3' and 5' hydroxyl groups as silyl derivatives. Acetylation of the vicinal hydroxyl groups and the exocyclic amino group followed by removal of silyl protection gave the protected nucleoside. Protection of the 5' hydroxyl group as the 4,4'-dimethoxytrityl ether followed by phosphitylation with 2-cyanoethyl-N,N,N',N'-tetraisopropylphosphorodiamidite gave the prosphoramidite reagent which was used to prepare a 12-mer oligodeoxynucleotide.     

佛波酯磷脂酰－L－丝氨酸（PEPS）中间体的合成工艺改进

目的改进佛波酯磷脂酰-L-丝氨酸（PEPS）的中间体3-苄基-2-（8-叔丁基二苯基硅氧辛酰基）-1-三苯甲基-Sn-甘油（9）和N-叔丁氧羰基-L-丝氨酸二苯甲酯（11）的合成工艺。方法以D-甘露醇为原料，经丙叉基保护、氧化-还原、苄基保护、脱丙叉保护、选择性保护、酯化、羧基还原、硅烷基保护合成化合物9；以L-丝氨酸为原料，经氨基、羧基保护合成化合物11。结果与结论目标化合物的结构经。H-NMR谱确证，改进后的工艺，缩短了合成路线，简化了柱色谱分离、纯化步骤，具有原料易得，操作简便，成本低廉的优点。     

In the search for new anticancer drugs. 19. A predictive design of N,N:N',N':N',N'-tri-1,2-ethanediylphosphorothioic triamide (TEPA) analogues

The nitroxyl-labeled analogues of N,N:N',N':N",N"-tri-1,2-ethanediylphosphoric triamide (TEPA), N,N:N',N'-bis(1,2-ethanediyl)-N"-[[(2,2,6,6-tetramethyl-1-oxypiperidi n-4- yl)amino]carbonyl]phosphoric triamide (5a) and N,N:N',N'-bis(1,2-ethanediyl)-N"-[[(2,2,5,5-tetramethyl-1-oxypyrrolid in-3- yl)amino]carbonyl]phosphoric triamide (11a), possess therapeutic indexes that are 8-12 times higher than those of thio-TEPA (1) and TEPA (2). The introduction of methyl groups into the aziridine ring, or the replacement of the nitroxyl moiety with hydroxylamine or amine derivatives, or with an adamantane moiety, results in compounds of lesser activity. An attempt is made to rationalize these results using a lipophilicity scale. A predictive design pattern is established.     

Synthesis of 8-(hydroxymethyl)-3,N(4)-etheno-2'-deoxycytidine, a potential carcinogenic glycidaldehyde adduct, and its site-specific incorporation into DNA oligonucleotides

The previously unreported glycidaldehyde adduct, 8-(hydroxymethyl)-3, N(4)-etheno-2'-deoxycytidine (8-HM-epsilondC), has been synthesized for the first time by reaction of 2'-deoxycytidine with bromoacetaldehyde at pH 4.5, followed by reduction with sodium borohydride. The adduct was characterized by UV, MS, and NMR. The compound was stable to neutral and acidic conditions but not in alkaline solution. The corresponding phosphoramidite was synthesized in good yield from the intermediate, 3, N(4)-ethenocarbaldehyde-2'-deoxycytidine, using the standard methodology and site-specifically incorporated in both 15- and 25-mer oligonucleotides, for studies on biochemical and biophysical properties. The resulting oligonucleotides were purified using HPLC, and the base composition was verified by HPLC after enzymatic digestion.     

3'-H-phosphonate synthesis of chiral benzo[a]pyrene diol epoxide adducts at N(2) of deoxyguanosine in oligonucleotides

A synthetic route to oligonucleotides containing N(2)-deoxyguanosine adducts at C-10 of the enantiomeric 7,8-diol 9,10-epoxides of 7,8,9,10-tetrahydrobenzo[a]pyrene in which the epoxide oxygen and the 7-hydroxyl group are trans is described. The present adducts result from the trans addition of N(2) of deoxyguanosine to the epoxide at C-10. Our synthesis proceeds via preparation of the 3'-H-phosphonate of a suitably protected deoxyguanosine N(2)-adduct. The blocking groups consisted of O(6)-allyl on the deoxyguanosine, acetates on the 7-, 8-, and 9-hydroxyl groups of the hydrocarbon moiety, and dimethoxytrityl on the 5'-hydroxyl group of the sugar. These blocking groups are well suited to oligonucleotide synthesis on solid supports. The free 3'-hydroxyl group of this nucleoside adduct was readily converted to its 3'-H-phosphonate with diphenyl phosphite in pyridine in high yield for both the 10R and 10S isomers. For synthesis of oligonucleotides, the first several nucleotides were incorporated onto the solid support with an automated synthesizer using standard phosphoramidite chemistry. The adducted deoxyguanilic acid residue was introduced as the H-phosphonate in a manual step (80% yield), followed by completion of the sequence on the synthesizer. Although a 10-fold excess of the 3'-H-phosphonate was used in the manual coupling step, as much as 70% of the reactant could be recovered. The 3'-H-phosphonate of the protected 10S nucleoside adduct was converted to the unblocked nucleotide adduct, various salts of which failed to form crystals suitable for X-ray analysis. Although submilligram quantities of this compound have been formed as mixed diastereomers by direct reaction of deoxyguanylic acid with racemic diol epoxide, the present study represents the first actual synthesis of the major DNA adduct formed from benzo[a]pyrene in mammals as its 3'-phosphate.     

Conformational Analysis of Therapeutic Proteins by Hydroxyl Radical Protein Footprinting

Unlike small molecule drugs, therapeutic protein pharmaceuticals must not only have the correct amino acid sequence and modifications, but also the correct conformation to ensure safety and efficacy. Here, we describe a method for comparison of therapeutic protein conformations by hydroxyl radical protein footprinting using liquid chromatography-mass spectrometry (LC-MS) as an analytical platform. Hydroxyl radical protein footprinting allows for rapid analysis of the conformation of therapeutic proteins based on the apparent rate of oxidation of various amino acids by hydroxyl radicals generated in situ. Conformations of Neupogen®, a patented granulocyte colony-stimulating factor (GCSF), were compared to several expired samples of recombinant GCSF, as well as heat-treated Neupogen®. Conformations of different samples of the therapeutic proteins interferon α-2A and erythropoietin were also compared. Differences in the hydroxyl radical footprint were measured between Neupogen® and the expired or mishandled GCSF samples, and confirmed by circular dichroism spectroscopy. Samples that had identical circular dichroism spectra were also found to be indistinguishable by hydroxyl radical footprinting. The method is applicable to a wide variety of therapeutic proteins and formulations through the use of separations techniques to clean up the protein samples after radical oxidation. The reaction products are stable, allowing for flexibility in sample handling, as well as archiving and reanalysis of samples. Initial screening can be performed on small amounts of therapeutic protein with minimal training in LC-MS, but samples with structural differences from the reference can be more carefully analyzed by LC-MS/MS to attain higher spatial resolution, which can aid in engineering and troubleshooting.

Electronic supplementary material

The online version of this article (doi:10.1208/s12248-012-9336-7) contains supplementary material, which is available to authorized users.Key words: biosimilars, hydroxyl radical protein footprinting, mass spectrometry, protein conformation, therapeutic proteins     

Use of N,O-bis-Fmoc-d-Tyr-ONSu for introduction of an oxidative iodination site into cholecystokinin family peptides

We report the synthesis of a new reagent for the introduction of an oxidative iodination site into the amino terminus of acid-labile peptides, and the use of this reagent to synthesize a novel affinity-labeling probe for the cholecystokinin (CCK) receptor. The acylation reagent, N,O-bis-fluorenylmethyloxycarbonyl-d -tyrosine hydroxysuccinimide ester, utilizes base-labile protection of both the alpha amino group and the aromatic ring hydroxyl. This can be safely removed to expose a cross-linkable free amino group on the aminopeptidase-resistant d -enantiomer of tyrosine. The synthetic probe, d -Tyr-Gly-Asp-Tyr(OSO₃H)-Nle-Gly-Trp-Nle-Asp-Phe-NH₂, was fully biologically active, could be radioiodinated to high-specific radioactivity (2000 Ci/mmol), bound with high affinity to the pancreatic CCK receptor, and covalently labeled the hormone-binding site. This reagent should be useful for the synthesis of a wide variety of analogues of CCK and other acid-labile peptides.     

Chirality of natural products: hyoscyamine and scopolamine

Monthly changes of the content-ratio between S-(-)- and R-(+)-hyoscyamine as well as those between S-(-)- and R-(+)-scopolamine in the leaves of Datura metel L. cultivated in the field, were quantitatively analyzed by the use of HPLC with a chiral adsorbent. It was found that S-(-)-isomer was predominant for hyoscyamine and the ratio of R-(+)-isomer gradually increased during the growth, whereas in the case of scopolamine, S-(-)-isomer was the sole one found throughout the cultivation period. The 1H-NMR study in the CD3OD solution has suggested that S-(-)-hyoscyamine (1) and S-(-)-scopolamine (2) take a "face-to-face" conformation between their tropane skeletons and the benzene rings of the tropic acid moieties. In the presence of an equimolar NaOD in the CD3OD solution, the racemization at C-2' of 1 and 2 proceeded more rapidly than the hydrolysis at the tropic acid ester bond, presumably due to the steric hindrance caused by their "face-to-face" conformations. In the D2O and H2O solutions, on the other hand, the racemization and the hydrolysis of 1 proceeded smoothly, while those of 2 did not occur. It has been supposed that these individual reaction manners are ascribable in considerable extent to the different basicity of N atom in each tropane skeleton of 1 and 2 and to stronger intramolecular hydrogen bond occurring between the carbonyl oxygen at C-1' and the hydroxyl group at C-3' in the tropic acid moiety of 1.     

Macromolecular prodrugs. XIII. Hydrosoluble conjugates of 17β-estradiol and estradiol-17β-valerate with polyaspartamide polymer

Two hydrosoluble conjugates of 17β-estradiol (ED) and estradiol-17β-valerate (EV) with polyaspartamide polymer were prepared and characterized. ED and EV were first chemically modified and bound to poly[α,β-(N-2-hydroxyethyl-DL-aspartamide)]-poly[α,β-(N-2-aminoethyl-DL-aspartamide)] (PAHA), a hydrosoluble polyaspartamide-type copolymer bearing both hydroxyl and amino groups. ED was first converted to 17-hemisuccinate (EDS) and then bound to PAHA. In the resulting conjugate PAHA-EDS, the estradiol moiety was linked to the polymer through a 2-aminoethylhemisuccinamide spacer. On the other hand, EV was first converted to estradiol-17β-valerate-3-(benzotriazole-1-carboxylate), which readily reacted with amino groups in PAHA affording the polymer-drug conjugate PAHA-EV. In the prepared conjugate PAHA-EV, the estradiol moiety was covalently bound to the polyaspartamide backbone by carbamate linkage, through an ethylenediamine spacer. The polymer-drug conjugates were designed and prepared with the aim to increase water-solubility, bioavailability and to improve drug delivery of the lipophilic estrogen hormone.     

Preparation of oligodeoxynucleotides containing a diastereoisomer of alpha-(N(2)-2'-deoxyguanosinyl)tamoxifen by phosphoramidite chemical synthesis

Women treated with an antiestrogen tamoxifen (TAM) for endocrine therapy or prevention of breast cancer show an increased risk of developing endometrial cancer. TAM-DNA adducts have been detected in the liver of rodents treated with TAM and in the endometrium of women taking TAM. The major TAM adducts have been identified as diastereoisomers of trans- and cis-forms of alpha-(N(2)-deoxyguanosinyl)tamoxifen (dG-N(2)-TAM) and alpha-(N(2)-deoxyguanosinyl)-N-desmethyltamoxifen. In the study presented here, we prepared oligodeoxynucleotides containing a diastereoisomer of dG-N(2)-TAM by phosphoramidite chemical synthesis. Initially, the trans- and cis-forms of alpha-aminotamoxifen (alpha-NH(2)-TAM) were synthesized from alpha-hydroxytamoxifen using the Mitsunobu reaction followed by hydrolysis. Thereafter by coupling the trans- and cis-form of alpha-NH(2)-TAM with the DMT-derivative of 2-fluoro-(O(6)-2-(trimethylsilyl)ethyl)-2'-deoxyinosine, the trans- and cis-forms of DMT-dG-N(2)-TAM, respectively, were prepared in high yield and used in the preparation of the phosphoramidite precursors. Large quantities of oligodeoxynucleotides containing a trans- or a cis-form of dG-N(2)-TAM were prepared efficiently by automated DNA synthesizer. The incorporation of dG-N(2)-TAM adduct into the oligodeoxynucleotides was confirmed using (32)P-postlabeling/polyacrylamide gel electrophoresis analysis. These site-specifically modified oligodeoxynucleotides will be used for exploring biological properties and three-dimensional structure of TAM-DNA adducts.