Azide-Alkyne Cycloaddition

As the most classical click chemical reaction, azide-alkyne cycloaddition catalyzed by copper ion has a fast reaction rate to obtain a triazole. It is insensitive to temperature, water, pH value, and other conditions, and has tolerance to the majority of functional groups. The products can be simply purified by filtration and extraction without the need for complex recrystallization or column chromatography.

Fig.1 Azide-alkyne cycloaddition catalyzed by copper ion. (Himo, et al., 2005)

Alkyne-Modified Oligonucleotides

Click chemistry can be applied to the synthesis of short, circular oligos, which are stable in serum and have a very strong potential to work in vivo. One of the simplest strategies for attaching labels to oligonucleotides is the click reaction between alkyne-modified oligonucleotides and azide-attached labels. Depending on the different applications, the alkyne group can be stuck to the 3' terminal, 5' terminal, or the interior of the oligonucleotide.

Fig.2 Labeling oligonucleotide by click chemistry. (CD BioGlyco)

Alkyne-based Oligonucleotide Modification Service at CD BioGlyco

CD BioGlyco has proven oligonucleotide modification strategies that support customers' access to a variety of alkyne-based oligo modifications. Please pour out your needs to us and we will tailor a personalized solution for you.

• 5'-alkyne linker: 5'-hexynyl modifier (5'-CHCH) connects the active alkyne group to the 5' end of the oligonucleotide. The C4 spacer effectively avoids steric hindrance and facilitates the attachment of functional labels. CD BioGlyco also offers the 5'-dibenzocyclooctyne (5'-DBCO) modifier, which allows for a click chemical reaction with the azide in the absence of a monovalent copper ion, efficiently coupling the label to the oligonucleotide.

Fig.3 Chemical structures of 5'-CHCH and 5'-DBCO. (CD BioGlyco)

• 3'-alkyne linker: Alkyne C3 can be used to attach the active alkyne group to the 3' end of the oligonucleotide. Then, various azide-modified functional groups such as fluorescent dyes, biotin, etc. can be efficiently and regioselectivity connected to the oligonucleotide. Likewise, we offer the 3'-DBCO modifier.

Fig.4 Chemical structures of alkyne C3 and 3'-DBCO. (CD BioGlyco)

• Internal alkyne linker: The active alkyne group can be inserted into the oligonucleotide by the alkyne-modified thymine deoxynucleotide (internal CHCH dT). In order to satisfy the reaction without copper ion catalysis, we also provide internal DBCO dT.

Fig.5 Chemical structures of internal CHCH dT and DBCO dT. (CD BioGlyco)

• 3'-(O-propargyl)-A/C/G/U 2'-5' linker & 2'-(O-propargyl)-A/C/G/U: The nucleic acid chain obtained by linking the 5'-azide-modified oligonucleotide with the 3'-propargyl-modified oligonucleotide is biocompatible and can be recognized by the polymerase and replicated correctly. CD BioGlyco provides various 3'-(O-Propargyl)-2'-5' linkers and 2'-(O-propargyl)-A/C/G/U. Our experts will choose the right modifier for your specific needs.

Fig.6 Chemical structures of 3'-(O-propargyl)-A/C/G/U 2'-5' linker and 2'-(O-propargyl)-A/C/G/U. (CD BioGlyco)

Applications

• Synthesis of fluorescently labeled oligonucleotides.
• Synthetic biotin-labeled oligonucleotides.
• Preparation of functionalized oligonucleotides by click chemistry.

Advantages

• Efficient synthesis and modification techniques.
• Almost no side reaction.
• Mild reaction conditions.
• Easy to operate, high yield.
• Oligonucleotides with stably connected functional labels.

CD BioGlyco aims to collaborate flexibly with customers to bring innovative and reliable Custom Carbohydrate Synthesis services. If you are interested in our Platforms, please feel free to contact us immediately.