Solution Phase Synthesis of Dithymidine Phosphorodithioate Using New S-Protecting Groups in Combination with a Chemoselective Coupling Reagent (PyNOP)

Abstract

ABSTRACT

A method for the synthesis of O-thymidin-3′-yl S-alkyl dithiophosphate monomers 1 with different S-protecting groups has been developed. These have been used for solution phase synthesis of dithymidine phosphorodithioate by a new phosphotriester method. Coupling reactions are fast (15 min.) and the products are free from phosphorothioate contaminations.     

Synthesis of 1,4-Anhydro-2-deoxy-D-ribitol Derivatives from Thymidine

Abstract

1,2-Dideoxyribose 5-O-succinate, a component of solid support employed in the synthesis of ribozymes, was synthesized from thymidine. The key step was elimination of nucleobase from 2 to afford glycal 3. A number of catalysts for this reaction were tested, resulting in improved and scaleable synthesis. Hydrogenation of the resulting glycal afforded 1,2-dideoxyribose derivative 4 in a high yield.     

Synthesis and Absolute Configuration of Pyriculol

A total synthesis of optically active pyriculol is described. The Wittig reaction between an aldehyde 19 and a triphenylphosphonium ylide 12 gave an intermediate 20. Successive treatment of 20 with p-toluenesulfonic acid, active manganese dioxide, and potassium carbonate gave (3′R,4′S)-pyriculol (23), which was identical with natural pyriculol (1) in all respects. From this synthesis, the absolute stereochemistry of pyriculol (1) was determined to be 2-[(3′R,4′S)-3′,4′-dihydroxy- (1′E,5′E)-1′,5′-heptadienyl]-6-hydroxybenzaldehyde     

Synthesis of ( ± )-Methyl Epijasmonate and ( ± )-Methyl Cucurbate

A novel synthesis of ( ± )-methyl epijasomonate (2) and the first synthesis of ( ± )-methyl cucurbate (4) were achieved starting from 2-allylcyclohexane-1,3-dione (8). The synthetic epimer 2 had a stronger jasmin flavor than the trans-isomer 1 with 95% purity.     

Straightforward Synthesis of 1-(2,3-Dideoxy-β-D-Glycero-Pent-2-Enofuranosyl)-Thymine

Abstract

A two steps synthesis of the antiviral drug (d4T) 3 from thymidine 1 is proposed, which implies a concomitant deprotection-elimination process by action of t-BuOK in DMF on 5′-O-t-butyldimethylsylil-3′-O-methanesulfonyl-thymidine 2.     

Preparation of an unprotected phosphotyrosine building block and its application in solid-phase synthesis of phosphopeptides

Summary A new and facile synthesis of tyrosine phosphorylated peptides has been developed.N ^α-Fmoc-Tyr(tBu)-OPfp was treated with TFA, phosphorylated with phosphorous oxychloride and the resulting phosphoric acid dichloride was hydrolysed to giveN ^α-Fmoc-Tyr(PO₃H₂)-OPfp1 in an overall yield of 98%. Compound1 was used in solid-phase peptide synthesis of phosphopeptides2, 3 and4, which are fragments of murine adipocyte lipid binding protein. The advantage of using the Pfp ester was the absence of pyrophosphates and other byproducts.     

内生真菌KLBMP0506对拟南芥的促生作用

【目的】研究植物内生菌Wickerhamomyces sp.KLBMP0506对拟南芥（Arabidopsis thaliana）的促生作用及潜在的促生机制。【方法】本研究以野生型拟南芥为试验材料,将其与菌株KLBMP0506进行平板共培养及盆栽接种试验,并测定拟南芥鲜重、干重、主根长、侧根数、叶绿素含量和可溶性糖含量等生长、生理指标,同时对筛选的与拟南芥侧根、主根形成及生长素合成和运输相关的11个基因进行实时荧光定量聚合酶链式反应（quantitative real-time polymerase chain reaction,qRT-PCR）分析。【结果】接种目的菌株KLBMP0506后,平板试验的拟南芥鲜重及侧根、盆栽试验的拟南芥鲜重、干重、茎长、叶绿素含量和可溶性糖含量均有一定程度的增加;分隔平板试验及菌株KLBMP0506发酵液中促生活性物质分析显示,该菌株产生的挥发性有机物质及其发酵液中的正丁醇和乙酸乙酯提取物均对拟南芥有明显的促生作用;此外,qRT-PCR分析显示KLBMP0506处理后,拟南芥中与侧根形成相关基因ABI4、FLA1的表达出现不同程度的下调,与生长素合成、运输相关基因AUX1、EIR1、YUC4的表达整体呈上调趋势,表明菌株KLBMP0506可能通过调控拟南芥中与侧根形成以及与生长素合成和运输相关基因的表达,而实现对拟南芥的促生作用。【结论】本研究明确了菌株KLBMP0506对模式植物拟南芥的促生作用,为其开发成为微生物菌肥提供理论依据。     

INTRACELLULAR Ca2+-MOBILIZING ADENINE NUCLEOTIDES. SYNTHESIS AND BIOLOGICAL ACTIVITY OF CYCLIC ADP-CARBOCYCLIC-RIBOSE AND C-GLYCOSIDIC ANALOG OF ADENOPHOSTIN A

We designed novel Ca²⁺-mobilizing purine nucleotides, cyclic ADP-carbocycl-icribose 4, and its inosine congener 5, and C-glycosidic adenophostin A 6. In the synthesis of cADPR analogs, the intramolecular condensation to form the pyrophosphate linkage should be the key step. We developed an efficient method for forming such an intramolecular pyrophosphate linkage by the activation of the phenylthiophosphate group with I₂ or AgNO₃. Using this method, we achieved to synthesize the target compounds 4 and 5. The synthesis of C-glycosidic analog 6 of adenophostin A was achieved using a temporary silicon-tethered radical coupling reaction for constructing (3′α, 1″α)-C-glycosi-dic structure as the key step.     

A Convenient Method for the Synthesis of ATP and Ap4A

Abstract

A bifunctional phosphorylating reagent, O-8-(5-chloroquinolyl) S-phenyl phosphorothioate (1) was employed for the synthesis of adenosine 5′-triphosphate (ATP) and diadenosine 5′-tetraphosphate (Ap₄A) from adenosine 5′-phosphate (AMP) on a large scale.     

One-Pot Synthesis of an AZT Boranophosphate Conjugated with Tyrosine: A Potential Prodrug Candidate

Abstract

A one-pot synthesis of P-tyrosinyl(P-O)-5′-P-AZT boranophosphate 7 via a phosphoramidite method is described. The P-boranophosphate diastereomers were separated by RP-HPLC, and their structures were confirmed by NMR and MS.     

An Efficient Synthesis of Methyl Jasmonate and Methyl Dihydrojasmonate

A simple and an efficient synthesis of methyl jasmonate (1) and methyl dihydrojasmonate (5) is described. Starting from alkyl acetoacetate or acetonedicarboxylate, 1 and 5 were obtained in only a few steps via intramolecular Michael addition.     

奥利万星中间体A82846B产生菌拟孢囊菌CCTCC M2020063全基因组序列分析与mbtH类基因的验证

[目的] 分析荒漠拟孢囊菌CCTCC M2020063中A82846B合成的代谢途径和关键基因。[方法] 使用Illumina二代测序和PacBio三代测序技术对荒漠拟孢囊菌CCTCC M2020063进行全基因组测序,利用Glimmer预测编码序列,使用HPLC和LCMS鉴定次级代谢产物,使用antiSMASH 5.0软件预测次级代谢产物合成基因簇。利用Geneious软件对A82846B合成相关基因进行分析,对其中的mbtH类基因着重分析。[结果] 本实验菌株鉴定为荒漠拟孢囊菌（Kibdelosporangium aridum）,基因组中有一条线性染色体,无质粒,序列全长12475688 bp,GC含量为66.27%,有11900个开放阅读框,共有47个基因簇。该菌株具有合成A82846B的能力,且生物合成相关基因位于Cluster32,包含33个基因,mbtH类基因gene07864的过表达促进A82846的合成,提升了26.42%,卤化酶基因为gene07859,与万古霉素、巴利霉素的卤化酶相似度较高。[结论] 本研究对荒漠拟孢囊菌CCTCC M2020063进行了基因组序列分析,获得了A82846B生物合成相关的功能基因信息,为A82846B的代谢途径和工程改造提供了强有力的基础。     

Synthesis of Polyaminooligonucleotides and Their Combinatorial Libraries

Abstract

A synthesis of phosphoramidites of 2′-deoxyadenosine and 2′-deoxyguanosine carrying a protected spermine moiety at N-6 and N-2 positions respectively is described. An approach to analyse properties of polyaminooligonucleotides using their synthetic combinatorial libraries is described and discussed. A synthesis of a polyaminooligonucleotide combinatorial library was carried out and the analysis of the library clearly showed that the presence of spermine moieties in oligodeoxyribonucleotides increases stability of their complexes.     

Synthesis of 3′-Azido-3′-Deoxythymidine-Terminated Oligonucleotide

Abstract

A method of completely chemical synthesis of 3′-azido-3′-deoxythymidine-terminated oligonucleotides via 5′-H-phosphonate of AZT is described.     

Cyclo-saligenyl-5-fluoro-2′-deoxyuridinemonophosphate (cycloSal-FdUMP) — A New Prodrug Approach for FdUMP

Abstract

The synthesis of cycloSal-FdUMP 3a-d as a new prodrug approach for FdU 1 is described. Phosphotriesters 3 release the FdUMP 2 selectively by a controlled, chemically induced tandem reaction in hydrolysis studies. The biological activity (IC₅₀) of cycloSal-phosphotriesters 3 was evaluated in FM3A/O cells and FM3A/TK^? cells.     

基于宏基因组研究植物乳酸菌或博落回提取物对山羊回肠微生物合成维生素B12的影响

【目的】探索研究反刍动物胃肠道微生物合成维生素B₁₂的方法,并评估植物乳酸菌或博落回提取物对断奶山羊回肠食靡微生物合成维生素B₁₂的影响。【方法】选取体重相近年龄相仿的断奶黑山羊20只,随机分为对照组(CON, n=7)、乳酸菌组(LAC, n=7)和博落回组(MAC, n=6)。CON组饲喂普通的日粮,LAC组饲喂基础日粮+10 g/d的植物乳酸菌(Lactobacillus plantarum P-8 strains, 4.0×10⁹ CFU/g),MAC组饲喂基础日粮+0.3 g/d的博落回提取物(Macleaya cordata 3.75%)。试验结束后,采集回肠中段食靡样品。利用宏基因组测序技术,比对最新功能基因数据库VB12Path和公共数据库KEGG,分析植物乳酸菌和博落回提取物对山羊回肠食靡微生物合成维生素B₁₂的影响。【结果】结果显示,比对VB12Path数据库共注释到55个与维生素B₁₂合成相关的基因。与CON组相比,LAC组和MAC组中合成维生素B₁₂基因的丰富度和均匀度降低(P<0.05）。3组间基因的β多样性也有显著的差异(P<0.05);比对KEGG数据库共注释到49个与维生素B₁₂合成相关的基因,LAC组的多样性与CON组没有差异,但MAC组的α多样性显著降低(P<0.05)。值得注意的是,比对VB12Path数据库和KEGG数据库均发现LAC组和MAC组中参与前咕啉2合成途径、参与无氧合成途径、有氧合成途径、参与重排转换途径以及腺苷钴胺素合成途径的部分基因(gltX、cbiT、cobT和btuD等)的丰度均显著地高于CON组(P<0.05)。【结论】2个数据库比对后的相似结果表明博落回提取物在对断奶山羊回肠微生物合成维生素B₁₂相关代谢上与植物乳酸菌的作用相似,均可以通过改变其多样性和提高部分关键基因的丰度,从而影响微生物合成维生素B₁₂的潜能,为后期博落回提取物和植物乳酸菌在畜牧养殖中的运用提供一定的理论支撑。此外,2个数据库比对的差异提示未来研究胃肠道微生物维生素B₁₂相关代谢时,应用多个数据库比对,能更全面精确地进行评价,为后期分析过程奠定研究基础和提供新的思路。     

Picomole Syntheses of High Quality Oligonucleotide Primers in Combination with the Preparation of Oligonucleotide Arrays

Abstract

The establishment of a new synthesis procedure for the preparation of oligonucleotide arrays is described. A modified phosphoramidite chemistry allowed the in situ synthesis of oligomer arrays on specially derivatized polypropylene membranes which can be used both for hybridisation experiments and for the isolation of the individual oligonucleotides.     

Synthesis of 2′,3′-Dideoxy- and 3′-Azido-2′,3′-dideoxy-pyridazine Nucleosides as Potential Antiviral Agents

Abstract

The synthesis of 4-methoxy-, 4-amino-3-chloro-, and 4-amino-1-(2,3-dideoxy-B-D-glycero-pentofuranosyl)pyridazin-6-one nucleosides, 6,19 and 20 is described. The synthesis of 3,4-dichloropyridazin-6-one (10) was accomplished in 44% overall yield using bromomaleic anhydride (17) as the starting material. The condensation of the silylated base of 10 with the halogenose 12 in the presence of trimethylsilyl triflate as a catalyst afforded a mixture of3,4-dichloro-1-(3,5-di-O-p-toluoyl-2-deoxy-B-D-erythro-pentofuranosyl)pyrridazin-6-one (13) in 67% and its α-anomer 14 in 12% yield, respectively. A series of 3′-sulfonate esters were prepared to explore the synthesis of 3-chloro-4-hydroxy-1-(3-azido-2,3-dideoxy-B-D-erythro-pentofuranosyl) pyridazin-6-one (32) via 6,3-anhydronucleoside analogues. Compounds 15, 19 and 20 were evaluated against human immunodeficiency virus, human cytomegalovirus, and herpes simplex virus type 1 but were inactive.     

Identification of a Degradation Intermediate of the Momilactone A Rice Phytoalexin by the Rice Blast Fungus

We have already shown that major rice diterpene phytoalexin, momilactone A, was detoxified by Magnaporthe oryzae. We report here the identification by NMR, MS, and chemical synthesis of 3,6-dioxo-19-nor-9β-pimara-7,15-diene (1) as the degradation intermediate. Compound 1 exhibited similar antifungal activity to that of momilactone A, indicating 1 to be a precursor of possible detoxified compounds.     

Synthesis of an Oligonucleotide Analogue of Ethenoadenosine

Abstract

A phosphoramidite building block derived from 11-carboxy-1,N ⁶-ethenoadenosine has been prepared to be used in a solid supported oligonucleotide synthesis.