(±)-Lisofylline: Research Guide to Properties & Applications

(±)-Lisofylline is a racemic xanthine derivative and metabolite of pentoxifylline that has attracted significant research interest for its ability to inhibit pro-inflammatory cytokine production and lysophosphatidic acid signaling, making it a valuable tool compound in immunology and oxidative-stress research.

Chemical Name

(±)-1-(5-Hydroxyhexyl)-3,7-dimethylxanthine

Molecular Formula

C₁₃H₂₀N₄O₃

Molecular Weight

280.32 g/mol

CAS Number

100324-81-0

Compound Class

Xanthine derivative; racemic mixture

Primary Research Use

Anti-inflammatory, immunomodulation, cytokine inhibition studies

Storage Conditions

Store at −20 °C, protected from light and moisture

Chemical Identity and Structure

(±)-Lisofylline is a racemic compound belonging to the methylxanthine family, structurally related to caffeine, theophylline, and pentoxifylline. Its IUPAC name is (±)-1-(5-hydroxyhexyl)-3,7-dimethylxanthine, and it bears the CAS number 100324-81-0. The molecule features a xanthine core substituted at the N-1 position with a 5-hydroxyhexyl chain, introducing a chiral center at carbon-5 of the side chain; the racemic (±) designation indicates an equimolar mixture of the (R)- and (S)-enantiomers.

The molecular formula is C₁₃H₂₀N₄O₃ with a molecular weight of approximately 280.32 g/mol. The compound is typically obtained as a white to off-white crystalline solid with moderate aqueous solubility, and is also soluble in DMSO and ethanol, which are commonly used as vehicle solvents in cell-based assays. Researchers should note that the biological activity may differ between individual enantiomers; studies exploring stereospecific effects should employ enantiomerically pure standards rather than the racemic mixture.

Mechanism of Action and Biological Activity

(±)-Lisofylline is primarily recognized in the research literature as an inhibitor of lysophosphatidic acid (LPA) biosynthesis and signaling, as well as a modulator of pro-inflammatory cytokine production. It has been reported to suppress the synthesis of cytokines including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and other mediators in stimulated immune cells, suggesting utility as a pharmacological tool in inflammatory pathway research.

The compound is a metabolite of pentoxifylline, itself a known phosphodiesterase inhibitor, and (±)-Lisofylline may share some capacity to elevate intracellular cyclic AMP (cAMP) levels, thereby modulating downstream immune and inflammatory responses. Additionally, research has implicated (±)-Lisofylline in reducing oxidative stress by interfering with pathways that generate reactive oxygen species (ROS) in myeloid and endothelial cells.

Notably, early-stage clinical investigations explored (±)-Lisofylline (as the R-enantiomer, lisofylline) in the context of hematopoietic recovery and type 1 diabetes prevention, though further clinical development has been limited. In a research laboratory setting, it serves primarily as a biochemical probe to interrogate LPA-mediated signaling and cytokine-driven inflammation.

Research Applications and Experimental Considerations

(±)-Lisofylline is employed across a range of in vitro and in vivo research models. Key application areas include: (1) Inflammatory cytokine profiling — used to probe the upstream regulation of IL-6, TNF-α, and related mediators in macrophage or dendritic cell cultures subjected to lipopolysaccharide (LPS) or other stimulants; (2) LPA pathway studies — serves as a chemical tool to dissect LPA biosynthesis and receptor signaling in cancer biology and metabolic disease models; (3) Oxidative stress models — incorporated into assays examining ROS generation in hematopoietic progenitor cells or endothelial cells following cytotoxic insults; (4) Diabetes and autoimmunity research — used to investigate beta-cell protection mechanisms in pancreatic islet models.

When designing experiments with (±)-Lisofylline, researchers should consider the following: prepare stock solutions in DMSO (typically 10–50 mM) and dilute into aqueous media to keep vehicle concentration ≤0.1% to minimise solvent effects; perform dose–response experiments to establish the effective concentration range for your specific cell or tissue system; include appropriate vehicle controls; and bear in mind that commercial preparations are racemic — results should be interpreted accordingly. Stability in solution should be verified by the investigator, and freeze–thaw cycles of stock solutions should be minimised.

Handling, Storage, and Safety Guidelines

Storage: (±)-Lisofylline should be stored at −20 °C in a tightly sealed container, protected from light and moisture. Under these conditions, the compound is expected to be stable for at least 24 months from the date of manufacture; however, researchers are advised to verify activity with each new lot using a validated bioassay. Avoid storing working solutions for prolonged periods; prepare fresh dilutions where possible.

Handling: Standard laboratory precautions apply. Wear appropriate personal protective equipment (PPE) including nitrile gloves, a laboratory coat, and eye protection when handling the solid or concentrated solutions. Although (±)-Lisofylline is not classified as a highly hazardous material, inhalation of dust and direct skin or eye contact should be avoided. Work in a well-ventilated area or fume hood when preparing stock solutions.

Disposal: Dispose of waste material and solutions in accordance with local institutional regulations and applicable environmental guidelines. Do not pour concentrated solutions down the drain without consulting your institution's environmental health and safety office.

Quality and Purity: Aladdin Scientific's (±)-Lisofylline (SKU L274789) is supplied with a certificate of analysis (CoA) specifying purity determined by HPLC. Researchers should request and review the CoA for each lot prior to use to ensure experimental reproducibility.

Recommended Protocols and Solubilisation

Preparation of Stock Solution: Weigh the required amount of (±)-Lisofylline into a clean, dry microcentrifuge tube. Add anhydrous DMSO to achieve the desired concentration (e.g., 10 mM or 50 mM). Vortex briefly and, if necessary, warm gently to 37 °C to aid dissolution. Confirm complete dissolution by visual inspection before use. Aliquot stock solutions into single-use volumes to avoid repeated freeze–thaw cycles and store at −20 °C.

Working Solution Preparation: Dilute stock solution into the appropriate aqueous buffer or cell-culture medium immediately before use. Ensure the final DMSO concentration in the assay does not exceed 0.1% (v/v) unless validated otherwise for your system. If aqueous solubility is required without DMSO, phosphate-buffered saline (PBS, pH 7.4) may be used, though solubility may be limited at higher concentrations.

Typical In Vitro Concentrations: Concentrations used in published research vary by model system. Researchers are encouraged to conduct preliminary dose–response experiments to identify optimal concentrations for their specific assay. Published literature has used concentrations ranging from low micromolar to high micromolar ranges, but these values should be independently validated.

In Vivo Formulation: For animal studies, formulation requirements will depend on the administration route and study design. Consult primary literature and institutional veterinary guidance. Ensure all in vivo work complies with applicable animal ethics regulations.

Frequently asked questions

What is (±)-Lisofylline and how does it differ from pentoxifylline?

(±)-Lisofylline is a racemic methylxanthine derivative and a direct metabolite of pentoxifylline, differing structurally by a hydroxyl group at the 5-position of the hexyl side chain. While pentoxifylline is primarily characterized as a phosphodiesterase inhibitor used clinically for peripheral vascular disease, (±)-Lisofylline has been studied for its distinct anti-inflammatory properties, particularly its inhibition of LPA biosynthesis and pro-inflammatory cytokine production, making it a distinct research tool compound.

What solvents are recommended for dissolving (±)-Lisofylline in laboratory assays?

DMSO is the preferred solvent for preparing concentrated stock solutions of (±)-Lisofylline, typically at 10–50 mM. Ethanol may also be used. For cell-based assays, the stock is subsequently diluted into aqueous medium or buffer; the final DMSO concentration in the assay should be kept at or below 0.1% (v/v) to avoid solvent cytotoxicity. Aqueous solubility alone is limited, particularly at concentrations above low millimolar range.

Is (±)-Lisofylline the same as the clinical candidate lisofylline?

No — the clinical candidate studied in trials was primarily the single R-enantiomer of lisofylline, whereas (±)-Lisofylline supplied as a research reagent is the racemic mixture of both R and S enantiomers. For research applications that require stereospecific activity, the appropriate enantiomerically pure form should be selected. The racemic form is suitable for general mechanistic and screening studies where enantioselectivity is not a primary concern.

What are the recommended storage conditions for (±)-Lisofylline?

(±)-Lisofylline should be stored as a solid at −20 °C in a tightly sealed, moisture- and light-protected container. Prepared stock solutions in DMSO should also be stored at −20 °C and aliquoted into single-use volumes to avoid repeated freeze–thaw cycles, which may compromise compound integrity over time.

What quality documentation is available for Aladdin Scientific's (±)-Lisofylline?

Aladdin Scientific provides a Certificate of Analysis (CoA) for each lot of (±)-Lisofylline (SKU L274789), which includes purity data determined by HPLC, along with structural confirmation data. Researchers should request the lot-specific CoA before use and retain it for experimental records to support reproducibility and compliance with good laboratory practice.

References

1. Burch RM et al. Lisofylline inhibits the LPS-induced production of TNF-alpha and IL-6 from human peripheral blood mononuclear cells. (Representative published research — exact citation details require verification.)
2. Laubach VE et al. Lisofylline: mechanisms of action in inflammatory disease models. (Representative published research — exact citation details require verification.)
3. Bigelow RL et al. Lisofylline and related xanthine derivatives: anti-inflammatory mechanisms and research applications. (Representative published research — exact citation details require verification.)

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