1,4-Diaminobutane Dihydrochloride: Properties & Lab Guide

1,4-Diaminobutane dihydrochloride is the stable, water-soluble dihydrochloride salt form of putrescine, a naturally occurring polyamine widely used in biochemical research, polyamine metabolism studies, and as a versatile difunctional building block in synthetic chemistry.

Chemical Name

1,4-Diaminobutane dihydrochloride (Putrescine dihydrochloride)

Molecular Formula

C₄H₁₂N₂ · 2HCl

Molecular Weight

161.07 g/mol

Physical Form

White to off-white crystalline powder

Solubility

Freely soluble in water; slightly soluble in ethanol

Storage Condition

Store at room temperature in a cool, dry, well-ventilated area, away from incompatible materials

CAS Number

333-93-7

Chemical Identity and Physical Properties

1,4-Diaminobutane dihydrochloride, commonly known as putrescine dihydrochloride, is the salt form of the diamine putrescine (1,4-butanediamine). Its molecular formula is C₄H₁₂N₂ · 2HCl with a molecular weight of approximately 161.07 g/mol and CAS number 333-93-7. The compound presents as a white to off-white crystalline solid at room temperature.

Conversion to the dihydrochloride salt significantly improves the compound's handling characteristics compared to the free base: it eliminates the hygroscopic and volatile nature of free putrescine, provides excellent aqueous solubility, and confers greater stability under standard laboratory storage conditions. Stock solutions in water are readily prepared and can be filter-sterilized for use in cell culture systems. The compound is compatible with common aqueous buffer systems used in biochemical assays.

Key Laboratory Applications

Polyamine Metabolism Research: Putrescine is one of the three principal naturally occurring polyamines (alongside spermidine and spermine) and serves as the direct biosynthetic precursor to spermidine. 1,4-Diaminobutane dihydrochloride is therefore an essential reagent in studies of the polyamine biosynthesis pathway, enzyme kinetics of ornithine decarboxylase (ODC) and spermidine synthase, and cellular polyamine pool manipulation. It is used to supplement polyamine-depleted culture media or to rescue cells treated with biosynthesis inhibitors such as DFMO (difluoromethylornithine).

Cross-linking and Conjugation Chemistry: The two primary amine groups of 1,4-diaminobutane make it a valuable homo-bifunctional linker in chemical synthesis and bioconjugation. It reacts with activated esters (NHS esters), aldehydes, isocyanates, and epoxides, enabling the construction of hydrogels, polymer networks, and labeled biomolecular probes. The defined four-carbon spacer arm provides controlled flexibility and length in the cross-linked product.

Biochemical Assays and Standards: The compound is used as an analytical standard or internal standard in HPLC and LC-MS/MS quantification of biogenic amines in biological fluids, food samples, and cell extracts. Its well-characterized UV and mass spectral properties facilitate method development.

Safe Handling, Storage, and Disposal

Handling Precautions: Although 1,4-Diaminobutane dihydrochloride is substantially less volatile and irritating than the free base, standard laboratory precautions apply. Wear appropriate personal protective equipment including nitrile gloves, safety spectacles, and a laboratory coat. Avoid generation of dust; if dust is generated during weighing, use a fume hood or respiratory protection. Avoid contact with skin, eyes, and mucous membranes. Wash hands thoroughly after handling.

Storage: Store in a tightly sealed container at room temperature in a cool, dry, and well-ventilated area. Protect from moisture and incompatible materials including strong oxidising agents and strong acids. When stored under recommended conditions, the compound is expected to be stable for an extended period; refer to the certificate of analysis for specific expiry information.

Disposal: Dispose of the compound and contaminated materials in accordance with local, regional, and national regulations for chemical waste. Do not dispose of via the general waste stream or drain. Consult your institution's environmental health and safety office for applicable waste disposal procedures.

Preparation of Working Solutions

Aqueous Stock Solutions: Weigh the required amount of 1,4-Diaminobutane dihydrochloride and dissolve in ultrapure (MilliQ-grade) water or an appropriate buffer to achieve the desired stock concentration (e.g., 100 mM). The compound dissolves readily without heating. Adjust pH if required using dilute NaOH, bearing in mind that the dihydrochloride salt will acidify the solution upon dissolution. Vortex or stir gently to ensure complete dissolution.

Sterilisation: For cell culture applications, pass the stock solution through a 0.22 µm syringe filter (PES or cellulose acetate membrane) under aseptic conditions. Avoid autoclaving, as prolonged heat exposure may affect compound integrity.

Storage of Prepared Solutions: Aqueous solutions should be aliquoted and stored at −20 °C for long-term use. Avoid repeated freeze-thaw cycles. Label aliquots with compound name, concentration, date of preparation, and expiry date. Use freshly prepared solutions where maximum accuracy is required for analytical applications.

Quality, Purity, and Regulatory Considerations

Specification and Purity: For research applications, purity of ≥98% (determined by titration or HPLC) is generally considered acceptable. For analytical reference standard use, higher purity grades may be required. Always consult the Certificate of Analysis (CoA) supplied with each lot for confirmed purity, identity (NMR, IR), and residual solvent data before use.

Lot-to-Lot Consistency: Researchers performing longitudinal studies or quantitative assays should document the lot number used and, where possible, reserve sufficient material from a single lot to complete the study. Contact Aladdin Scientific technical support if custom purity grades or bulk quantities are required.

Regulatory Status: 1,4-Diaminobutane dihydrochloride is not a controlled substance under standard international regulatory frameworks. However, users should verify applicable local regulations. It is intended for research use only and is not approved for human therapeutic or veterinary use.

Frequently asked questions

What is the difference between 1,4-Diaminobutane dihydrochloride and free-base putrescine?

1,4-Diaminobutane dihydrochloride is the salt form of putrescine formed by protonation of both amine groups with hydrochloric acid. Compared to the free base, the dihydrochloride salt is a solid at room temperature, is non-volatile, less odorous, more stable on the bench, and easier to weigh accurately. It is freely soluble in water and is the preferred form for most laboratory applications. When preparing solutions, account for the higher molecular weight (161.07 vs 88.15 g/mol for the free base) and the pH-lowering effect upon dissolution.

How should I prepare a 100 mM stock solution of 1,4-Diaminobutane dihydrochloride?

Dissolve 161.07 mg of 1,4-Diaminobutane dihydrochloride (MW 161.07 g/mol) in 10 mL of ultrapure water to obtain a 100 mM stock solution. Mix gently until fully dissolved. Note that dissolution will lower the pH; adjust with dilute NaOH if a specific pH is required for your application. For cell culture use, sterilize the solution by passing it through a 0.22 µm filter. Store aliquots at −20 °C.

Can 1,4-Diaminobutane dihydrochloride be used to rescue cells from DFMO-induced polyamine depletion?

Yes. DFMO (α-difluoromethylornithine) inhibits ornithine decarboxylase (ODC), blocking endogenous putrescine synthesis and thereby depleting cellular polyamine pools. Supplementing culture medium with exogenous putrescine (as the dihydrochloride salt) replenishes the intracellular putrescine pool and allows downstream synthesis of spermidine and spermine. This approach is widely used as an experimental control to confirm that observed phenotypes are specifically attributable to polyamine depletion rather than off-target effects of DFMO.

Is 1,4-Diaminobutane dihydrochloride suitable for cross-linking applications?

Yes. The compound provides two primary amine groups separated by a four-carbon flexible spacer, making it useful as a homobifunctional cross-linker or spacer molecule in bioconjugation and polymer chemistry. It reacts with NHS esters, aldehydes (Schiff base formation), and other electrophilic functional groups. For cross-linking reactions, the free base form or neutral pH buffered solutions of the dihydrochloride salt are typically used to ensure the amine groups are in the reactive, unprotonated form; adjust solution pH accordingly before initiating the reaction.

How should 1,4-Diaminobutane dihydrochloride be stored to ensure long-term stability?

Store the solid compound in a tightly sealed container at room temperature in a cool, dry, and well-ventilated location, away from moisture, strong oxidizers, and strong acids. Under these conditions, the dihydrochloride salt form is stable for an extended period. Aqueous stock solutions should be aliquoted and stored at −20 °C; avoid repeated freeze-thaw cycles. Always refer to the product Certificate of Analysis for lot-specific stability data.

References

1. Tabor CW and Tabor H. Polyamines. Annual Review of Biochemistry. 1984;53:749-790. doi:10.1146/annurev.bi.53.070184.003533
2. Pegg AE. Mammalian polyamine metabolism and function. IUBMB Life. 2009;61(9):880-894. doi:10.1002/iub.230
3. Heby O. Role of polyamines in the control of cell proliferation and differentiation. Differentiation. 1981;19(1):1-20. doi:10.1111/j.1432-0436.1981.tb01123.x
4. Aladdin Scientific. Product Data Sheet: 1,4-Diaminobutane dihydrochloride, SKU D106194. Aladdin Scientific, Shanghai.

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