N3-Ethyl Pseudouridine: Properties, Uses & Lab Handling Guide

N3-Ethyl pseudouridine is a synthetic, N3-alkylated analog of the naturally occurring RNA nucleoside pseudouridine, used in research to probe RNA modification biology and to evaluate the impact of N3-substitution on nucleoside base-pairing, stability, and translational activity.

Chemical Name

N3-Ethyl pseudouridine (5-(β-D-Ribofuranosyl)-3-ethyluracil)

Parent Compound

Pseudouridine (Ψ), the most abundant post-transcriptional RNA modification

Key Structural Feature

Ethyl group introduced at N3 position of the uracil base, blocking canonical Watson-Crick hydrogen bonding at that site

Research Utility

Tool compound for studying N3-modification effects on RNA function, translation, and immune recognition

Supplier Reference

Aladdin SKU: N1425682; also referenced as MCE HY-152417

Recommended Storage

Store according to supplier SDS; typically at -20 °C, protected from moisture and light (verify with product SDS)

Background and Chemical Properties

Pseudouridine (Ψ) is the most prevalent post-transcriptional modification found in eukaryotic RNA, formed by the isomerization of uridine such that the glycosidic bond is relocated from N1 to C5 of the uracil base. This rearrangement exposes a free N1-H in the major groove, which participates in additional hydrogen bonding and is thought to confer enhanced RNA structural stability.

N3-Ethyl pseudouridine is a chemically synthesized analog in which an ethyl group is appended at the N3 nitrogen of the pseudouridine base. Because N3 participates in Watson-Crick base-pairing in natural pseudouridine, the introduction of a bulky ethyl substituent at this position disrupts or significantly modifies canonical hydrogen bonding, making N3-Ethyl pseudouridine a valuable probe for dissecting the mechanistic contributions of individual functional groups to RNA behavior.

Key physicochemical considerations (verify exact values against product Certificate of Analysis):

• Molecular scaffold: pseudouridine ribonucleoside with N3-ethyl substitution on the uracil moiety.
• The ribose sugar retains the standard β-D-furanose configuration.
• Solubility: moderate aqueous solubility is expected; dissolution in DMSO followed by aqueous dilution is commonly employed for stock preparation (confirm with SDS).

Research Applications

N3-Ethyl pseudouridine serves primarily as a mechanistic probe and synthetic building block in the following research contexts:

1. RNA modification biology: Researchers use N3-alkylated pseudouridine analogs to map the functional importance of the N3-H hydrogen bond in pseudouridine-containing RNA structures, ribosomal RNAs, and small nuclear RNAs (snRNAs).
2. mRNA therapeutics research: The field of nucleoside-modified mRNA (as exemplified by the use of N1-methylpseudouridine in approved mRNA vaccines) has created demand for a library of modified nucleosides. N3-Ethyl pseudouridine enables comparative studies of how different N3 substitutions affect innate immune activation, translation efficiency, and mRNA stability relative to unmodified or N1-modified analogs.
3. Chemical biology tool compound: The compound can be incorporated into oligonucleotides via chemical synthesis to probe local RNA structure, protein-RNA interaction surfaces, and decoding fidelity at the ribosome.
4. Synthetic chemistry reference standard: N3-Ethyl pseudouridine may serve as an intermediate or reference standard in the preparation of more complex modified nucleoside libraries.

Note: Specific biological activity data should be sought from the primary literature or validated assay data; the above represents general research-context utility of this compound class.

Handling, Dissolution, and Storage Guidelines

Adherence to proper handling procedures is essential for maintaining compound integrity and ensuring reproducible experimental results. The following represents general best-practice guidance for nucleoside analog reagents; always consult the product-specific Safety Data Sheet (SDS) and Certificate of Analysis (CoA) supplied by Aladdin Scientific.

Personal Protective Equipment (PPE)

• Wear appropriate laboratory coat, nitrile gloves, and eye protection when handling.
• Work in a well-ventilated area or under a fume hood if generating dust or aerosols.

Stock Solution Preparation

• Allow the vial to equilibrate to room temperature before opening to prevent moisture condensation on the compound.
• For aqueous stock solutions, dissolution in nuclease-free water or appropriate buffer (e.g., phosphate-buffered saline, pH 7.4) is recommended where solubility permits.
• If aqueous solubility is insufficient, prepare a primary stock in anhydrous DMSO (typically 10–100 mM), then dilute into aqueous media. Ensure the final DMSO concentration is compatible with your assay (generally ≤0.1% v/v for cell-based assays).
• Vortex gently and confirm complete dissolution visually before use.

Storage Conditions

• Store the bulk material at -20 °C in a sealed, desiccated container, protected from light.
• Aliquot stock solutions to avoid repeated freeze-thaw cycles, which can degrade nucleoside analogs.
• Record the date of preparation and expiry on each aliquot.

All storage temperature and stability data should be confirmed against the Aladdin Scientific product SDS and CoA for SKU N1425682, as manufacturer-verified data supersedes general guidance.

Quality, Purity, and Regulatory Considerations

Research-grade nucleoside analogs such as N3-Ethyl pseudouridine are intended for laboratory research use only and are not approved for human therapeutic or diagnostic use. The following quality considerations apply:

• Purity: Confirm purity grade (e.g., ≥95% or ≥98% by HPLC) from the Certificate of Analysis provided with each lot. Contact Aladdin Scientific customer service to request CoA documentation for SKU N1425682.
• Identity verification: Common analytical methods for identity confirmation include ¹H NMR, ¹³C NMR, high-resolution mass spectrometry (HRMS), and HPLC-UV. Cross-reference the observed data against literature values for pseudouridine analogs.
• Lot-to-lot consistency: For studies requiring high reproducibility (e.g., in vitro transcription or cell-based assays), request lot-specific analytical data and consider maintaining a frozen master stock from a single lot.
• Regulatory status: This compound is supplied for research use only (RUO). Users are responsible for compliance with all applicable local, national, and institutional regulations regarding the purchase, storage, and use of research chemicals.

Frequently asked questions

What is the difference between N3-Ethyl pseudouridine and N1-methylpseudouridine used in mRNA vaccines?

N1-methylpseudouridine bears a methyl group at the N1 position of the pseudouridine base and has been validated in approved mRNA vaccines for its ability to reduce innate immune activation while maintaining high translational efficiency. N3-Ethyl pseudouridine, by contrast, carries an ethyl group at the N3 position, which disrupts Watson-Crick hydrogen bonding at N3 rather than at N1; its immunological and translational properties relative to N1-methylpseudouridine have not been established in clinical applications and require experimental characterization for each intended use.

How should I prepare a working solution of N3-Ethyl pseudouridine for in vitro transcription reactions?

First, allow the vial to reach room temperature before opening. If the compound has adequate aqueous solubility, dissolve it in nuclease-free water or an appropriate reaction-compatible buffer to prepare a stock solution (e.g., 10–100 mM); confirm the concentration spectrophotometrically if an accurate extinction coefficient is available. If aqueous solubility is limiting, an intermediate stock in anhydrous DMSO can be prepared and diluted to a final DMSO concentration that does not inhibit the polymerase being used. Always verify the CoA and SDS for product-specific solubility data for SKU N1425682.

Is N3-Ethyl pseudouridine stable at room temperature, and how should long-term stocks be managed?

Like most nucleoside analogs, N3-Ethyl pseudouridine is expected to be more stable when stored cold, dry, and protected from light. Long-term storage at -20 °C in single-use aliquots is recommended to avoid repeated freeze-thaw degradation. Room-temperature stability has not been independently verified in this guideline; users should rely on the manufacturer's stability data in the product SDS and CoA for definitive guidance.

Can N3-Ethyl pseudouridine be incorporated into RNA oligonucleotides by solid-phase synthesis?

In principle, pseudouridine analogs with appropriate protecting groups and phosphoramidite activation can be incorporated into RNA oligonucleotides via standard solid-phase synthesis protocols. However, whether a phosphoramidite derivative of N3-Ethyl pseudouridine is commercially available or has been synthesized for this purpose should be verified in the primary literature and with your oligonucleotide synthesis supplier; the Aladdin SKU N1425682 product is the free nucleoside form.

References

1. Karikó K, Buckstein M, Ni H, Weissman D. Suppression of RNA recognition by Toll-like receptors: the impact of nucleoside modification and the evolutionary origin of RNA. Immunity. 2005;23(2):165-175. doi:10.1016/j.immuni.2005.06.008
2. Roundtree IA, Evans ME, Pan T, He C. Dynamic RNA modifications in gene expression regulation. Cell. 2017;169(7):1187-1200. doi:10.1016/j.cell.2017.05.045
3. Charette M, Gray MW. Pseudouridine in RNA: what, where, how, and why. IUBMB Life. 2000;49(5):341-351. doi:10.1080/152165400410182
4. Aladdin Scientific product page. N3-Ethyl pseudouridine, SKU N1425682. [Supplier product information; cross-referenced to MCE HY-152417].

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.