In vivo, (R)-[11C]rolipram has been used for selective binding studies to PDE4, providing the basis for studying intracellular cAMP signaling in the myocardium and other peripheral tissues. The compound has been investigated in a Phase 2 clinical trial for asthma. It has also been studied for potential applications in inflammation and neurological disorders. Male Hartley guinea pigs This study aimed to investigate the effects of rolipram, a phosphodiesterase inhibitor, on brain tissue regeneration. Trimethyltin-injected mice, an animal model of hippocampal tissue regeneration, was created by a single injection of trimethyltin chloride (2.2 mg/kg, intraperitoneally). Daily rolipram administration (10 mg/kg, intraperitoneally) was performed from the day after trimethyltin injection until the day before sampling. In Experiment 1, brain samples were collected on day 7 postinjection of trimethyltin following the forced swim test. In Experiment 2, bromodeoxyuridine (150 mg/kg, intraperitoneally/day) was administered on days 3-5 and sampling was on day 21 postinjection of trimethyltin. Samples were routinely embedded in paraffin and sections were obtained for histopathological investigation. In Experiment 1, rolipram-treated mice showed shortened immobility times in the forced swim test. Histopathology revealed that rolipram treatment had improved the replenishment of neuronal nuclei-positive neurons in the dentate gyrus, which was accompanied by an increase in the percentage of phosphorylated cyclic AMP response element-binding protein-positive cells. In addition, rolipram had decreased the percentage of ionized calcium-binding adapter protein 1-positive microglia with activated morphology and the number of tumor necrosis factor-alpha-expressing cells. In Experiment 2, double immunofluorescence for bromodeoxyuridine/neuronal nuclei revealed an increase of double-positive cells in rolipram-treated mice. These results demonstrate that rolipram effectively promotes brain tissue regeneration by enhancing the survival of newborn neurons and inhibiting neuroinflammation.Neuroreport. 2024 Sep 4;35(13):832-838.

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In vivo animal studies for (R)-(-)-Rolipram have been conducted in various models. The radiolabeled compound (R)-[11C]rolipram is used for PET imaging studies to assess PDE4 distribution and occupancy in brain and peripheral tissues. Efficacy studies in models of inflammation, asthma, and neurological disorders have been performed. The compound is typically administered via intraperitoneal or oral routes.

Targets	Phosphodiesterases/PDE4 (R)-(-)-Rolipram targets phosphodiesterase 4 (PDE4), the primary enzyme responsible for hydrolyzing cyclic AMP (cAMP) in immune cells and neurons. By inhibiting PDE4, it increases intracellular cAMP levels, which modulates various signaling pathways involved in inflammation, cognition, and neuronal function.
ln Vitro	In a dose-dependent manner, caspase-1 cleavage and IL-1β secretion are suppressed by increasing cAMP synthesis with the adenylate cyclase activator forskolin or decreasing cAMP hydrolysis with the phosphodiesterase inhibitors Isobutylmethylxanthine (IBMX) and (R)-(-)-Rolipram. (R)-(-)-Rolipram is the more active enantiomer of rolipram and shows 2- to 10-fold greater potency than the (S)-(+)-enantiomer against PDE4. It is approximately 3 times more potent than (S)-(+)-rolipram. Detailed IC50 values for PDE4 inhibition have been characterized in enzymatic assays. The compound is used as a tool for studying cAMP signaling.
ln Vivo	In anesthetized, ventilated OA-sensitive guinea pigs, S-(+)-Rolipram reduces OA-induced bronchoconstriction with ID50 values of approximately 0.25 mg/kg i.v. Histamine- and leukotriene D4-induced bronchoconstriction are not affected by doses of S-(+)-Rolipram which abolishes the response to OA. Higher doses (3-10 mg/kg) reduce histamine-, but not the leukotriene D4-induced bronchoconstriction. In conscious OA-sensitive guinea pigs, intragastric pretreatment with S-(+)-Rolipram dose-dependently reduces both the OA-induced decreases in specific conductance as well as the corresponding pulmonary eosinophil influx as assessed by both bronchoalveolar lavage and histological evaluation.
Enzyme Assay	PDE4 inhibition with rolipram boosts P2Y11/IL-1R-induced upregulation of CXCR7 expression and CCL20 production in an epidermal growth factor receptor dependent manner. Using an astrocytoma cell line, naturally expressing CXCR7 but lacking CXCR4, P2Y11/IL-1R activation effectively induced and CXCR7 agonist TC14012 enhanced CCL20 production even in the absence of PDE4 inhibition. Moreover, CXCR7 depletion by RNA interference suppressed CCL20 production. In macrophages, the simultaneous activation of P2Y11 and CXCR7 by their respective agonists was sufficient to induce CCL20 production with no need of PDE4 inhibition, as CXCR7 activation increased its own and eliminated CXCR4 expression. Finally, analysis of multiple CCL chemokines in the macrophage secretome revealed that CXCR4 inactivation and CXCR7 activation selectively enhanced P2Y11/IL-1R-mediated secretion of CCL20. Altogether, our data establish CXCR7 as an integral component of the P2Y11/IL-1R-initiated signaling cascade and CXCR4-associated PDE4 as a regulatory checkpoint. Cell Mol Life Sci. 2024 Mar 13;81(1):132. Cell-free PDE4 enzyme assays for (R)-(-)-Rolipram utilize purified PDE4 enzyme and cAMP as substrate. The hydrolysis of cAMP to AMP is measured in the presence of increasing concentrations of the compound. Activity is quantified using radiometric (3H-cAMP), fluorescence, or coupled enzyme assays. IC50 values are determined from concentration-response curves. The compound's enantioselectivity can be assessed by comparing with (S)-(+)-rolipram.
Cell Assay	The entrapment and subsequent release of the important cAMP-specific PDE4 inhibitor/drug Rolipram, which has antibreast cancer properties, was assessed on the breast cancer cell line MCF-7. Rolipram has important therapeutic applications, one of the most significant in recent times being the treatment of Covid-19-triggered pneumonia and cytokine storms. As for cancer chemotherapy, the localization of drug, targeted delivery, and sustained release are extremely important issues, and it seemed worthwhile to explore the potential of the bilosomes and niosomes to entrap and release Rolipram. The important finding is that niosomes perform much better than bilosomes in the hormone-responsive breast cancer mileau MCF-7. Moreover, there was a 4-fold decrease in the IC50 of Rolipram encapsulated in niosomes compared to Rolipram alone. On the other hand, bilosome-encapsulated Rolipram shows higher IC50 value. The results can be further understood by molecular docking studies. ACS Appl Bio Mater. 2024 Jan 15;7(1):369-378. Cells expressing PDE4 (e.g., immune cells, neurons) are treated with (R)-(-)-Rolipram at various concentrations. Intracellular cAMP levels are measured by ELISA or using cAMP biosensors. Downstream signaling (e.g., PKA activation, CREB phosphorylation) is assessed by Western blot. Functional assays such as cytokine production in immune cells or neuronal excitability can be performed to evaluate the biological consequences of PDE4 inhibition.
Animal Protocol	Dissolved in 100% PEG at an appropriate concentration; 1 mL/kg; i.v. injection
ADME/Pharmacokinetics	(R)-(-)-Rolipram is orally bioavailable. As a small molecule (MW 275.34, formula C16H21NO3) with moderate lipophilicity, it has favorable drug-like properties for CNS penetration. PK parameters including Tmax, half-life, clearance, and bioavailability have been characterized in preclinical species and humans. The compound is metabolized primarily via hepatic pathways.
Toxicity/Toxicokinetics	Toxicity data for (R)-(-)-Rolipram are available from preclinical and clinical studies. PDE4 inhibitors are known to have dose-limiting gastrointestinal toxicities (nausea, emesis) due to PDE4 expression in the brainstem. The (R)-enantiomer may have a different safety profile compared to the racemate. Standard toxicological assessments have been conducted to support clinical development.
References	[1]. Bile Acids Control Inflammation and Metabolic Disorder through Inhibition of NLRP3 Inflammasome. Immunity. 2016 Oct 18;45(4):944.
Additional Infomation	(-)-Lolipran is the (R)-enantiomer of lolipran and also the (+)-enantiomer of lolipran. The (R)-enantiomer of lolipran is a phosphodiesterase inhibitor with antidepressant activity. (R)-(-)-Rolipram (molecular formula C16H21NO3) is also known as (4R)-4-[3-(cyclopentyloxy)-4-methoxyphenyl]pyrrolidin-2-one. It is the active enantiomer of the PDE4 inhibitor rolipram. The compound has been extensively studied for its potential therapeutic applications in inflammation, asthma, and neurological disorders. It is intended for research use only.

Molecular Formula	C16H21NO3
Molecular Weight	275.34
Exact Mass	275.152
Elemental Analysis	C, 69.79; H, 7.69; N, 5.09; O, 17.43
CAS #	85416-75-7
Related CAS #	Rolipram;61413-54-5;(S)-(+)-Rolipram;85416-73-5
PubChem CID	448055
Appearance	Off-white to light yellow solid powder
Density	1.2±0.1 g/cm3
Boiling Point	472.7±45.0 °C at 760 mmHg
Melting Point	134 °C
Flash Point	239.7±28.7 °C
Vapour Pressure	0.0±1.2 mmHg at 25°C
Index of Refraction	1.552
LogP	1.43
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	4
Heavy Atom Count	20
Complexity	341
Defined Atom Stereocenter Count	1
SMILES	COC1=C(C=C(C=C1)[C@H]2CC(=O)NC2)OC3CCCC3
InChi Key	HJORMJIFDVBMOB-LBPRGKRZSA-N
InChi Code	InChI=1S/C16H21NO3/c1-19-14-7-6-11(12-9-16(18)17-10-12)8-15(14)20-13-4-2-3-5-13/h6-8,12-13H,2-5,9-10H2,1H3,(H,17,18)/t12-/m0/s1
Chemical Name	(4R)-4-(3-cyclopentyloxy-4-methoxyphenyl)pyrrolidin-2-one
Synonyms	(R)-(+)-ZK-62711; SB 95952;SB95952; (R)-(-)-Rolipram; 85416-75-7; (R)-ROLIPRAM; (R)-4-(3-(cyclopentyloxy)-4-methoxyphenyl)pyrrolidin-2-one; (-)-ROLIPRAM; (4R)-4-[3-(CYCLOPENTYLOXY)-4-METHOXYPHENYL]PYRROLIDIN-2-ONE; R-Rolipram; Rolipram, (-)-;SB-95952;ME-3167; ZK-62711; ME3167; ZK62711; ME 3167; ZK 62711
HS Tariff Code	2934.99.9001
Storage	Powder      -20°C    3 years                      4°C     2 years In solvent   -80°C    6 months                   -20°C    1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility (In Vitro)

DMSO: 55 mg/mL (199.8 mM) Water:<1 mg/mL Ethanol:55 mg/mL (199.8 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.08 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. Solubility in Formulation 2: ≥ 2.5 mg/mL (9.08 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. View More Solubility in Formulation 3: ≥ 2.5 mg/mL (9.08 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. Solubility in Formulation 4: 30% PEG400+0.5% Tween80+5% propylene glycol:10 mg/L  (Please use freshly prepared in vivo formulations for optimal results.)