Conjugate must be stable to deprotection conditions Isolation of free carboxylate requires deprotection with sodium hydroxide
2-Chlorotrityl Protected Requires trityl group to be removed and further activation On Column conjugate must be stable to deprotection conditions Isolation of free carboxylate can be done using ammonium hydroxide, AMA or sodium hydroxide No need to remove 2-chlorotrityl group prior to deprotection Useful for conjugation with amino acids and small peptides for library formation
to unreactive amide. Our Carboxy-dT also falls into this category in that the methyl ester protecting the carboxylate has to be hydrolyzed with sodium hydroxide. An alternative approach to 5′-carboxymodification was described1 a few years
ago in which the carboxylate is protected with a 2-chlorotrityl group. This protecting group is simply removed using the standard deblock cycle to generate a free carboxyl group on an otherwise fully protected oligonucleotide. Using a standard peptide
coupling reaction, the carboxyl group can be reacted with amines or amino acids to form conjugates. The procedure, shown in Figure 2, is also fully compatible with the formation of oligonucleotide peptide conjugates or libraries. Alternatively if a 5′ free carboxylate is desired, the oligonucleotide can be cleaved and deprotected trityl-on or trityl-off using ammonium hydroxide or AMA with no amide formation, as shown in Figure 3.1620458-09-4 manufacturer We have found that the optimal coupling time for this product is 3 minutes and the chlorotrityl group can be removed using the standard deblock procedure on the synthesizer.14605-22-2 Description It should be noted that the chlorotrityl group is a different color from the regular DMT group so trityl monitors may not register the release properly.PMID:30855917 It should also be noted that the 2-chlorotrityl group is removed during oligo deprotection, as shown in Figure 3, and is incompatible with RP purification techniques. We are happy to introduce 5′-CarboxyModifer C5 to extend our range of electrophilic modifiers.
1. Synthesize the 5′-carboxylate-modified oligo trityl-off and retain on the support. 2. Pre-activate the carboxylic acid by treating the support-bound oligo with HATU (100 equivalents) and HOBT (100 equivalents) in dry DMF (100L). 3. Warm the reaction to 35 and shake support for 35 minutes. 4. After activation of the acid is complete, add triethylamine (100 equivalents) and the amine (100 equivalents). 5. Warm the conjugation mixture to 35 and shake the support for 1 hour. 6. The unbound amine can easily be removed from the solid support by washing successively with DMF (2 x 100L), ethanol (2 x 200L), and distilled water (2x 200L). 7. The conjugate can then be deprotected and removed from the solid support using ammonium hydroxide or AMA using conditions appropriate for deprotection of the nucleobases. 8. The conjugate is now ready for purification.
DNA-MEDIATED CHARGE TRANSPORT: A NOVEL PROPERTY OF DNA WITH DIVERSE APPLICATIONS
P.L. Bartels and J.K. Barton Division of Chemistry and Chemical Engineering California Institute of Technology Pasadena, CA 91125 DNA is traditionally thought of as the cell’s library of genetic information. However, work in the Barton lab over the last three decades has brought to light a new side of DNA, revealing the ability of this molecule to facilitate the transport of charge over long molecular distances. This fascinating property of DNA has been investigated under biologically relevant conditions using a variety of redox prob.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com