UnyLinker dimer impurity characterization and process improvement

Herein, we describe the isolation and characterization of a UnyLinker dimer which, if left uncontrolled, can become incorporated in oligonucleotide products. The dimer is formed as a result of an unusual intermolecular osmium-catalyzed etherification. We demonstrate that by simply replacing H₂O₂ as the co-oxidant with NMO, none of the UnyLinker dimer impurity is formed.     

Sinularia属珊瑚中嘧啶类化合物的分离与鉴定

分离和鉴定了采自中国南海硇州岛软珊瑚Sinularia Bassica样本中新的嘧啶类化合物。样本用工业酒精提取,提取物溶液经乙酸乙酯萃取后,萃取物经硅胶柱层析,以极性不断增大的溶剂体系(石油醚-乙酸乙酯、氯仿-甲醇)梯度洗脱,再经过HPLC分离,得到2,4(1H,3H)-嘧啶二酮、5-甲基-2,4(1H,3H)-嘧啶二酮、1,3-二甲基-2,4(1H,3H)-嘧啶二酮和5-甲氧基-1,3-二甲基-2,4(1H,3H)-嘧啶二酮4种新的嘧啶类化合物,其结构通过红外光谱、1HNMR和13C NMR等光谱数据分析确定。     

First synthesis of dioxadithiaporphycene with a benzene ring fused onto the double bond

Dioxadithiaporphycenes 5 and 5′ were synthesized by using the Suzuki cross-coupling and McMurry coupling reactions as the key steps. This approach provided an access to the first dioxadithiaporphycene derivative 15 with a benzene ring fused onto the double bond.     

Design and Synthesis of Novel Peptide Nucleic Acid Monomers

All of the four nucleobases in DNA have replaced the 4‐hydroxy group of N‐[2‐(tert‐butoxycarbonylaminomethyl)‐trans‐4‐hydroxy] tetrahydropyrrole acetic acid methyl ester with cis ‐stereochemistry. An efficient route for the synthesis of N‐[2‐(tert‐butoxycarbonylaminomethyl)‐trans‐4‐hydroxy]‐tetrahydropyrrole acetic acid methyl ester has been developed. Starting with this intermediate, the protected monomers were synthesized by the Mitsunobu reaction or via its tosylate.     

1,2-Cyclic Monoacyl-rac-Glycerothio-phosphates of Cantharidin Analogues

Mylabris,thedriedbodyoftheChineseblisterbeetle,hasbeenusedasChinesemedicineforover2000years.Itsactiveconstituent,cantharidin,hasantitumoractivitiesandcausesleukocytosis'.Thesynthesisofcyclicglycerophospholipidcontainingcantharidinanalogueshassofarnotbeenreportedinliterature.Theconjugatesofthistypearenotonlynewprodrugsofcantharidinantitumoragentsbutalsomaygeneratetwocytotoxicgroupsagainstdifferenttargetsitesinsideaneoplasticcell'.Suchtypesofcompoundsmaybeofinterestinchemistry,biochemistryandph…     

General Information to Obtain Spherical Particles with Ordered Mesoporous Structures

Conditions for the synthesis of aluminum organophosphonate (AOP) and aluminophosphate (AlPO) spheres containing periodic mesopores were optimized and demonstrated to be general morphological controls for the surfactant‐assisted synthesis of mesoporous materials. High‐quality AOP and AlPO spheres with uniform mesopores were obtained at low and high temperatures, respectively. The aerosol‐assisted synthesis of materials with uniform mesopores was categorized by using the difference in relative density of soluble AOP and AlPO oligomers that interact with ethylene oxide (EO) units in EO_nPO_mEO_n triblock copolymer (PO=propylene oxide). Then, ordered mesoporous structures are constructed with the adequate amount of species in resultant frameworks, and the number of interactive points in soluble species determines the resultant density of the frameworks after self‐assembly. Consequently, temperature‐dependent synthesis, which allows controlled infiltration of soluble species to match the density of resultant frameworks, is required for the formation of ordered mesoporous structures under morphological control.     

1H, 13C and 15N NMR assignments for N6‐isopentenyladenosine/inosine analogues

The complete ¹H, ¹³C and ¹⁵N NMR signals assignments of some new isopentenyladenosine analogues were achieved using one‐ and two‐dimensional experiments (gs‐NOESY, gs‐HMQC and gs‐HMBC). Copyright © 2010 John Wiley & Sons, Ltd.     

2000 Vol.11 No.8 P.Preparation of AChE Inhibitors From Jujubogenin

A dammarane derivative dihydrojujubogenin-2-en-1-one, which possesses a skeleton and pharmacophore partially similar to those of Territrem B, a potent AChE inhibitor, was synthesized via three different paths. The anti-AChE activity of this compound and related analogue was measured.