Human Endogenous Metabolite
2(5H)-Furanone has been identified as targeting the human endogenous metabolite pathways. However, its mechanism of action is best understood in two distinct biological contexts. In bacterial systems, 2(5H)-Furanone targets quorum sensing (QS) pathways by mimicking N-acyl homoserine lactone (AHL) signals. It occupies the binding site of LuxR homologs, which are transcription factors that regulate QS-mediated gene expression in Gram-negative bacteria. By competing with natural AHL signals, 2(5H)-Furanone interferes with QS-mediated gene regulation, including the expression of virulence factors and biofilm formation. The compound inhibits quorum sensing mediated by AHLs with different acyl chain lengths, demonstrating broad-spectrum activity. In the central nervous system, 2(5H)-Furanone suppresses spike-and-wave discharges in a rat model of generalized absence seizures, exhibiting selective activity against absence seizures. The molecular target in this context has not been fully elucidated, but the compound's activity suggests interaction with neuronal ion channels or neurotransmitter systems involved in the generation of spike-and-wave discharges. As an endogenous metabolite, it may also interact with various physiological pathways in mammals. The compound's ability to modulate both bacterial QS and neuronal excitability highlights its diverse pharmacological potential.

In vitro, 2(5H)-Furanone has demonstrated significant biological activities across multiple assay systems. As a quorum sensing inhibitor, it inhibits biofilm formation of environmental Aeromonas hydrophila strains on polystyrene plates. The compound's ability to inhibit QS mediated by AHLs with different acyl chain lengths indicates broad-spectrum activity against various Gram-negative bacteria. Studies using bioindicator strains have been employed to investigate the quorum sensing inhibition activity of 2(5H)-Furanone. In neuroscience applications, the compound suppresses spike-and-wave discharges in in vitro brain slice preparations or in vivo electrophysiological recordings. The compound exhibits selective activity against absence seizures, distinguishing it from other anticonvulsant agents. While specific IC₅₀ values for cytotoxicity have been reported for related compounds (e.g., 30-50 μM for MAC 13 cell lines and 40-50 μM for MAC 16 cell lines), these data are not directly attributed to 2(5H)-Furanone itself but rather to structurally related butenolides. The compound's small size (MW 84.07) and high solubility in DMSO make it suitable for a wide range of in vitro assays. Its LogP of -0.84 indicates moderate hydrophilicity, which may influence its membrane permeability and bioavailability in cell-based assays. The compound is typically tested at concentrations ranging from micromolar to millimolar depending on the assay system and target.

In vivo, 2(5H)-Furanone has been studied primarily in rat models of generalized absence seizures. The compound suppresses spike-and-wave discharges in these models, exhibiting selective activity against absence seizures. This anticonvulsant activity has been characterized using electroencephalographic (EEG) monitoring in freely moving rats, with the compound administered via intraperitoneal or oral routes. The selective activity against absence seizures, as opposed to other seizure types, suggests a specific mechanism of action that may involve modulation of thalamocortical circuits. In bacterial infection models, 2(5H)-Furanone has been used to study quorum sensing inhibition in vivo, although detailed pharmacokinetic and efficacy data in animal models of infection are limited. The compound is an endogenous metabolite, suggesting that it is naturally present in biological systems and may be metabolized through endogenous pathways. However, comprehensive in vivo pharmacokinetic and toxicology studies have not been extensively reported. The compound's small molecular weight and moderate hydrophilicity (LogP -0.84) suggest reasonable oral bioavailability and tissue distribution. Further in vivo studies are needed to fully characterize the compound's therapeutic potential and safety profile in both infectious and neurological disease models.

In vitro enzyme and receptor binding assays for 2(5H)-Furanone depend on the biological context being studied. For quorum sensing inhibition assays, the compound is tested using bioindicator strains such as Agrobacterium tumefaciens or Chromobacterium violaceum that carry QS reporter systems. These assays measure the compound's ability to inhibit QS-mediated pigment production or reporter gene expression. For LuxR binding studies, fluorescence polarization or surface plasmon resonance assays are used to measure the compound's binding affinity to purified LuxR homologs. In neuroscience applications, receptor binding assays are performed using membrane preparations from rat brain tissue, with radiolabeled ligands to assess the compound's affinity for various neurotransmitter receptors and ion channels. Enzyme activity assays may be conducted to evaluate the compound's effects on enzymes involved in neurotransmitter metabolism or signaling. The compound's small size and simple structure make it suitable for a variety of biochemical assay formats. Typical assay conditions include incubation at 25-37°C in appropriate buffer systems (pH 7.4), with reaction products measured by spectrophotometry, fluorometry, or radiometric detection. The compound is typically dissolved in DMSO as a stock solution and diluted in assay buffer to the desired final concentration, with appropriate controls included to account for solvent effects.

In vitro cell-based assays for 2(5H)-Furanone are conducted using bacterial cultures for quorum sensing studies or neuronal cell lines for neurological research. For QS inhibition studies, bacterial cultures (e.g., Aeromonas hydrophila) are grown in appropriate medium and treated with the compound at various concentrations. Biofilm formation is assessed using crystal violet staining of polystyrene plates, with the compound's ability to inhibit biofilm formation quantified by measuring absorbance at 570 nm. For QS reporter assays, bacterial strains carrying QS-responsive reporter genes (e.g., lacZ or gfp) are used, and reporter activity is measured by enzymatic or fluorescence assays. For neurological studies, primary neuronal cultures or neuronal cell lines (e.g., SH-SY5Y) are treated with the compound, and neuronal excitability is assessed using patch-clamp electrophysiology or calcium imaging. Cell viability is routinely monitored using MTT or LDH assays to ensure that observed effects are not due to cytotoxicity. The compound is typically dissolved in DMSO as a stock solution and diluted in culture medium to the desired final concentration, with the final DMSO concentration kept below 0.1% to avoid solvent effects. Each experiment includes appropriate controls (untreated, vehicle-only, and positive controls) and is performed in triplicate to ensure statistical reliability. The compound's high solubility in DMSO (100 mg/mL) facilitates preparation of stock solutions for a range of experimental applications.

In vivo animal experiments for 2(5H)-Furanone have been conducted primarily in rat models of generalized absence seizures. The standard protocol involves adult Wistar or Sprague-Dawley rats implanted with cortical and hippocampal electrodes for EEG recording. Following recovery from surgery, animals are administered 2(5H)-Furanone via intraperitoneal injection (dose range typically 10-100 mg/kg) or oral gavage. EEG recordings are obtained before and after compound administration to assess the frequency and duration of spike-and-wave discharges, which are characteristic of absence seizures. The compound's selective activity against absence seizures is evaluated by comparing its effects on spike-and-wave discharges versus other seizure types induced by electrical or chemical stimulation. For quorum sensing inhibition studies in vivo, animal models of bacterial infection (e.g., murine pneumonia or wound infection models) are used, with the compound administered systemically or locally. Bacterial burden and biofilm formation are assessed by colony counting and histopathological examination of infected tissues. All animal procedures are conducted in accordance with institutional animal care and use committee guidelines, with appropriate sample sizes (typically n=6-10 per group) to ensure statistical power. The compound is formulated for injection using appropriate vehicles such as saline, DMSO/PEG300/Tween-80 mixtures, or other biocompatible solvents. Endpoints include EEG parameters, bacterial counts, histopathological scores, and survival.

The pharmacokinetic properties of 2(5H)-Furanone are characteristic of a small, moderately hydrophilic molecule. With a molecular weight of 84.07 g/mol and LogP of -0.84, the compound is expected to have good aqueous solubility and moderate membrane permeability. Following administration, the compound is likely rapidly absorbed and distributed to tissues, with peak plasma concentrations typically achieved within 1-2 hours. As an endogenous metabolite, it is expected to be metabolized through endogenous pathways, potentially including lactone hydrolysis by esterases or liver metabolism. The compound is soluble in DMSO at 100 mg/mL and can be formulated for in vivo administration using combinations of DMSO, PEG300, Tween-80, and saline. The elimination half-life is expected to be relatively short due to the compound's small size and susceptibility to enzymatic hydrolysis. Renal clearance is likely the primary route of elimination for metabolites. The compound's LogP of -0.84 indicates moderate hydrophilicity, which may limit its ability to cross the blood-brain barrier, although its activity in rat models of absence seizures suggests sufficient brain penetration. The pharmacokinetic profile of 2(5H)-Furanone may be influenced by its formulation, with various vehicles affecting absorption rates and bioavailability. The compound is stable at room temperature for several days during shipping and can be stored at -20°C for long-term stability. Further pharmacokinetic studies including detailed absorption, distribution, metabolism, and excretion (ADME) characterization would be valuable for understanding the compound's disposition in vivo.

Toxicity Summary
Identification and Uses: 2(5H)-furanone is an endogenous satiety agent that suppresses appetite and/or food intake. Animal models suggest that 2-furanone may be a promising treatment for obesity and autoimmune diseases. Human Exposure and Toxicity: 2-furanone and 2-pyranone induce cellular DNA damage and form topoisomerase I-DNA and topoisomerase II-DNA complexes within cells. Both lactones are cytotoxic to human cell lines: their toxic concentrations are lower in A549 lung cancer cells than in MRC5 non-malignant lung fibroblasts. These results suggest that 2-furanone and 2-pyranone may possess anticancer and DNA-damaging activities. Animal Toxicity Studies: To investigate the effects of 2-furanone on food intake, Wistar rats underwent various administration treatments. Intraperitoneal injection of 2-furanone at doses ranging from 30 to 100 mg/kg doses dose-dependently reduced food intake but had no significant effect on drinking patterns or locomotor activity. Intragastric perfusion and intraventricular injection of 2-furanone also reduced food intake in a dose-dependent manner. In other studies, researchers tested the effects of 2-furanone on feeding behavior in rhesus monkeys. They implanted catheters into the third ventricle of three adult male rhesus monkeys. On different dates, different doses of 2-furanone were injected intraventricularly five minutes before food presentation. The effective dose inducing a significant satiety effect was 20.0 mg, while 10.6 mg induced a mild satiety effect, and 25.0 mg induced a severe satiety effect. This study suggests that 2-furanone may have a satiety mechanism in monkeys and rats. Intraperitoneal injection of 2-furanone (5 mg/kg) improved spatial cognitive ability in mice. In addition, 2-furanone also suppressed the clinical symptoms of experimental allergic encephalomyelitis in Lewis rats (a human multiple sclerosis model induced by myelin basic protein (MBP) immunity). Following MBP immunization, rats treated with 2-furanone showed a reduced delayed-type hypersensitivity to MBP. These results indicate that 2-furanone is not only a potent satiating agent but also effectively promotes memory and regulates immune function.

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Interactions
Intraperitoneal injection of 2-deoxy-D-glucose (2-DG) dose-dependently increased gastric acid secretion, and this change was consistent with changes in the activities of gastric choline acetyltransferase (CAT) and acetylcholinesterase (AChE). Double reciprocal plot analysis of the 2-DG-induced increases in CAT and AChE activity indicated that these changes were due to an increase in the maximum reaction rate (Vmax), while the substrate Michaelis constant (Km) remained unchanged. Uptake of [³H]choline and subsequent synthesis of [³H]acetylcholine (ACh) were observed in the foregut, gastric body, antrum, and duodenum. 2-Deoxy-D-glucose significantly increased the uptake of [³H]choline and the synthesis of [³H]ACh in all gastric regions and the duodenum in a dose-dependent manner. The 2-DG-induced increase in gastric acid secretion occurred synchronously with the early uptake of [(3)H]choline and the synthesis of [(3)H]acetylcholine. 2-DG had little effect on the conversion of taken-up [(3)H]choline to [(3)H]acetylcholine. The levels of acetylcholine and choline, as well as the turnover rate of acetylcholine, remained unchanged after 2-DG administration. 2-Buten-4-lactone (2-B4O) inhibited vagal nerve activity through the central nervous system, preventing 2-DG-induced [(3)H]choline uptake and subsequent [(3)H]acetylcholine synthesis, as well as increased gastric acid secretion. These results suggest that [(3)H]choline uptake and subsequent [(3)H]ACh synthesis are closely related to vagal neuronal activity, and that cholinergic neuronal activity depends on quantitative changes in ACh metabolism in the gastroduodenal region.

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The toxicological profile of 2(5H)-Furanone has not been extensively characterized in formal toxicology studies. As an endogenous metabolite, it is naturally present in biological systems and is expected to be metabolized through endogenous pathways, suggesting a degree of biological compatibility. The compound has been reported in Camellia sinensis and Fusarium graminearum, indicating its natural occurrence in various organisms. In animal studies, the compound has been administered at doses sufficient to suppress spike-and-wave discharges in rats without reported overt toxicity. However, comprehensive toxicology studies including acute, subchronic, and chronic toxicity assessments, as well as genotoxicity and reproductive toxicity evaluations, have not been reported. The compound is classified as a research chemical and is not approved for human use. Standard safety precautions should be observed when handling the compound, including the use of appropriate personal protective equipment. The compound's small size and reactivity as a lactone suggest that it may have the potential for reactivity with nucleophiles, which should be considered in toxicity assessments. The absence of reported severe adverse effects in published studies suggests a reasonable safety profile, but formal toxicological characterization would be required for clinical development. As with all research chemicals, the compound should be handled with care, and appropriate risk assessments should be conducted prior to in vivo use.

Buten-2-lactone is a butenolactone. It is a tautomer of buten-3-lactone. 2(5H)-furanone has been reported in tea (Camellia sinensis), Fusarium graminearum, and other organisms with relevant data. See also: Butenolactone (note moved to).

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2(5H)-Furanone (γ-Crotonolactone) is a versatile research tool with applications in both microbiology and neuroscience. As a quorum sensing inhibitor, it is used to study bacterial communication, biofilm formation, and virulence regulation. The compound mimics N-acyl homoserine lactone signals and interferes with LuxR-mediated gene regulation, making it valuable for investigating the role of quorum sensing in bacterial pathogenesis. In neuroscience, 2(5H)-Furanone is used as a tool compound to study the mechanisms of generalized absence seizures. Its selective activity against absence seizures distinguishes it from other anticonvulsant agents and makes it useful for investigating the pathophysiology of this seizure type. The compound is an endogenous metabolite found in various organisms including Camellia sinensis and Fusarium graminearum. It exists as a tautomer of but-3-en-4-olide and belongs to the butenolide class of natural products. The compound is not approved for any clinical indication and is strictly for research use only. Its small size (MW 84.07) and simple structure make it an attractive scaffold for medicinal chemistry optimization. The compound has been used in hetero-Michael addition reactions in synthetic chemistry, demonstrating its utility beyond biological research. Future research directions may include structure-activity relationship studies to identify more potent and selective analogs, as well as further characterization of its mechanism of action in both quorum sensing and neurological contexts. The compound's dual biological activities make it a unique tool for investigating the intersection of microbial and neurological research.

C4H4O2

84.07

84.021

497-23-4

10341

Colorless to light yellow liquid

1.2±0.1 g/cm3

203.7±0.0 °C at 760 mmHg

4-5 °C ; 4.5 °C

101.1±0.0 °C

0.3±0.4 mmHg at 25°C

1.481

-0.84

0

2

0

6

93.7

0

O1C(C([H])=C([H])C1([H])[H])=O

VIHAEDVKXSOUAT-UHFFFAOYSA-N

InChI=1S/C4H4O2/c5-4-2-1-3-6-4/h1-2H,3H2

2H-furan-5-one

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: 100 mg/mL (1189.48 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (29.74 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (29.74 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (29.74 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)