184717-99-5Relevant academic research and scientific papers
Solid Phase Stepwise Synthesis of Polyethylene Glycols
Khanal, Ashok,Fang, Shiyue
supporting information, p. 15133 - 15142 (2017/10/31)
Polyethylene glycol (PEG) and derivatives with eight and twelve ethylene glycol units were synthesized by stepwise addition of tetraethylene glycol monomers on a polystyrene solid support. The monomer contains a tosyl group at one end and a dimethoxytrityl group at the other. The Wang resin, which contains the 4-benzyloxy benzyl alcohol function, was used as the support. The synthetic cycle consists of deprotonation, Williamson ether formation (coupling), and detritylation. Cleavage of PEGs from solid support was achieved with trifluoroacetic acid. The synthesis including monomer synthesis was entirely chromatography-free. PEG products including those with different functionalities at the two termini were obtained in high yields. The products were analyzed with ESI and MALDI-TOF MS and were found close to monodispersity.
Beyond PEG2000: Synthesis and functionalisation of monodisperse pegylated homostars and clickable bivalent polyethyleneglycols
Szekely, Gyoergy,Schaepertoens, Marc,Gaffney, Piers R.J.,Livingston, Andrew G.
, p. 10038 - 10051 (2014/08/18)
A new strategy to access highly monodisperse, heterobifunctional linear polyethylenglycols (PEGs) has been designed. This was built around unidirectional, iterative chain extension of a 3-arm PEG homostar. A mono-(4,4′-dimethoxytriphenylmethyl) octagol building block, DmtrO-EG 8-OH, was constructed from tetragol. After six rounds of chain extension, the monodisperse homostar reached the unprecedented length of 56 monomers per arm (PEG2500). The unique architecture of the synthetic platform greatly assisted in facilitating and monitoring reaction completion, overcoming kinetic limitations, chromatographic purification of intermediates, and analytical assays. After chain terminal derivatisation, mild hydrogenolytic cleavage of the homostar hub provided heterobifunctional linear EG56 chains with a hydroxyl at one end, and either a toluene sulfonate, or a tert-butyl carboxylate ester at the other. A range of heterobifunctional, monodisperse PEGs was then prepared having useful cross-linking functionalities (-OH, -COOH, -NH2, -N3) at both ends. A rapid preparation of polydisperse PEG homostars, free of multiply cross-linked chains, is also described. The above approach should be extendable to other high value oligomers and polymers.
Efficient preparation of organic substrate-RNA conjugates via in vitro transcription
Fiammengo, Roberto,Musilek, Kamil,Jaeschke, Andres
, p. 9271 - 9276 (2007/10/03)
A concise synthetic way has been developed for the preparation of guanosine monophosphate derivatives carrying a decaethylene glycol spacer at their 5′-oxygen to which are attached a range of organic substrates. The four different compounds, prepared via a convergent synthetic strategy, carry a tethered benzylallyl ether residue (1a), an anthracene (1b), a benzyl carbamate residue (1c), or a primary amino group (1d), respectively. All four compounds have been successfully incorporated at the 5′-end of a 25-mer long RNA transcript via T7 RNA polymerase, and no inhibition of chain elongation could be observed. Under proper conditions, 1a and 1b can be incorporated up to 90-95% and 1c up to 68%. The amino-terminated initiator 1d is incorporated less efficiently although still up to 49%. These results show that the more hydrophobic the guanosine monophosphate derivative is, the higher is its enzymatic incorporation.
Structural optimization of non-nucleotide loop replacements for duplex and triplex DNAs
Rumney IV, Squire,Kool, Eric T.
, p. 5635 - 5646 (2007/10/02)
Described are studies systematically exploring structural effects in the use of ethylene glycol (EG) oligomers ' as non-nucleotide replacements for nucleotide loops in duplex and triplex DNAs. The new structurally optimized loop replacements are more stab
