Target family: Phosphodiesterases, 3',5'-cyclic nucleotide (PDEs) (type: enzyme)
Target: phosphodiesterase 4B

Ligand: 6-Hydroxy-5,7-dimethoxyflavone (Natural product)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Primary target: no
Median affinity: 5.070000171661377 pIC50
Reference (Journal): 6-Hydroxy-5,7-dimethoxy-flavone suppresses the neutrophil respiratory burst via selective PDE4 inhibition to ameliorate acute lung injury.
Published in: Free Radic Biol Med

Ligand: apremilast (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: yes
Approval source: FDA (2014), EMA (2015)
Primary target: yes
Median affinity:  pIC50
Reference (Journal): Apremilast is a selective PDE4 inhibitor with regulatory effects on innate immunity.
Published in: Cell Signal

Ligand: CBS-3595 (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Primary target: no
Median affinity: 5.71999979019165 pIC50
Reference (Journal): Discovery of N-{4-[5-(4-Fluorophenyl)-3-methyl-2-methylsulfanyl-3H-imidazol-4-yl]-pyridin-2-yl}-acetamide (CBS-3595), a Dual p38α MAPK/PDE-4 Inhibitor with Activity against TNFα-Related Diseases.
Published in: J Med Chem

Ligand: CDP840 (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Primary target: no
Median affinity: 8.069999694824219 pKi
Reference (Journal): CDP840: a novel inhibitor of PDE-4.
Published in: Cell Biochem Biophys

Ligand: crisaborole (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: yes
Approval source: FDA (2016), EMA (2020)
Primary target: no
Median affinity:  -
Reference (Journal): Discovery and structure-activity study of a novel benzoxaborole anti-inflammatory agent (AN2728) for the potential topical treatment of psoriasis and atopic dermatitis.
Published in: Bioorg Med Chem Lett

Ligand: example 2 [WO2013026797A1] (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Primary target: no
Median affinity: 8.140000343322754 pIC50
Reference (Patent): Novel piperidino-dihydrothienopyrimidine sulfoxides and their use for treating copd and asthma

Ligand: ibudilast (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: yes
Primary target: yes
Median affinity: 7.190000057220459 pIC50
Reference (Journal): Recent advances on phosphodiesterase 4 inhibitors for the treatment of asthma and chronic obstructive pulmonary disease.
Published in: J Med Chem

Ligand: MK-0359 (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Primary target: no
Median affinity: 9.300000190734863 pIC50
Reference (Journal): L-454,560, a potent and selective PDE4 inhibitor with in vivo efficacy in animal models of asthma and cognition.
Published in: Biochem Pharmacol

Ligand: nerandomilast (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Primary target: no
Median affinity: 8 pIC50
Reference (Journal): BI 1015550 is a PDE4B Inhibitor and a Clinical Drug Candidate for the Oral Treatment of Idiopathic Pulmonary Fibrosis.
Published in: Front Pharmacol

Ligand: PF-07038124 (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Primary target: no
Median affinity: 9.300000190734863 pIC50
Reference (Patent): Boron Containing PDE4 Inhibitors

Ligand: Ro20-1724 (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Primary target: no
Median affinity: 6.400000095367432 pIC50
Reference (Journal): Expression, purification, and characterization of human cAMP-specific phosphodiesterase (PDE4) subtypes A, B, C, and D.
Published in: Biochem Biophys Res Commun

Ligand: roflumilast (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: yes
Approval source: EMA (2010), FDA (2011)
Primary target: yes
Median affinity: 9.399999618530273 pIC50
Reference (Journal): Quinolines as a novel structural class of potent and selective PDE4 inhibitors: optimisation for oral administration.
Published in: Bioorg Med Chem Lett

Ligand: roflupram (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Primary target: no
Median affinity:  -
Reference (Journal): Roflupram, a Phosphodiesterase 4 Inhibitior, Suppresses Inflammasome Activation through Autophagy in Microglial Cells.
Published in: ACS Chem Neurosci

Ligand: rolipram (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Primary target: no
Median affinity: 9 pIC50
Reference (Journal): Expression, purification, and characterization of human cAMP-specific phosphodiesterase (PDE4) subtypes A, B, C, and D.
Published in: Biochem Biophys Res Commun

Ligand: RS-25344 (Synthetic organic)
Interaction type: Inhibitor
Action: Inhibition
Ligand approved: no
Median affinity: 6.5 pIC50
Reference (Journal): Comparison of recombinant human PDE4 isoforms: interaction with substrate and inhibitors.
Published in: Cell Signal