Would anyone kindly explain,
why during oligosynthesis I have to use dry capping reagents CapA and CapB?
In many manuals it is mandated that all reagents for oligosynthesis must be water-free, except for the oxidizer, to which water is added intentionally.
1. To my best knowledge, chemistry of the capping process will not change if water is present in the reaction misture, at the capping step.
2. The capping step preceeds the oxidation step. So if some water is present during the capping it will not hamper the efficiency of oxidation.
3. My only possible explanation is that trivalent phosphorus P(III) in the form of phosphite is unstable in the presence of water and will hydrolyse. But I don't know for sure.
What is the exact reason to prepare CapA and CapB dry?
Check https://hal.archives-ouvertes.fr/hal-02197142/document
https://atdbio.com/nucleic-acids-book/Solid-phase-oligonucleotide-synthesis
Kindly check this paper
https://www.carlroth.com/medias/SDB-2256-MT-EN.pdf?context=bWFzdGVyfHNlY3VyaXR5RGF0YXNoZWV0c3wzNzAwOTF8YXBwbGljYXRpb24vcGRmfHNlY3VyaXR5RGF0YXNoZWV0cy9oMDkvaDBmLzkwNTUzOTgyOTc2MzAucGRmfDgwMTAwMTE2M2I1ZGZhODRkYjI5Zjc5ZThiN2I0MDE0ODk3ZDRhMDg4MjVkODZiNjczYzU5Zjk1YTExYWJlOTA
Dear Chinaza and Kiprotich, thank you for your replies.
I studied the sources at links that you have provided.
Finally, the conclusion is that the presence of just small amount of water during the capping step itself will not hamper the efficiency of the process as long as there is a huge molar excess of anhydride and methylimidazole in the process.
The reason (to keep CapA, CapB dry) seems to stabilize the reagents themselves during storage.
Again, thank you!
- Badges
- Science topic