Two new isoxazolines from the husks of Xanthoceras sorbifolia Bunge

Two new isoxazoline compounds, 1-oxa-2-azaspiro[4.5]dec-2-ene-8β-ol (1) and 1-oxa-2-azaspiro[4.5]dec-2-ene-8α-ol (2), were isolated from the husks of fruits of Xanthoceras sorbifolia Bunge and their structures were determined by spectroscopic analyses, including X-ray crystallography, HRESI-MS, UV, IR, and 1D and 2D NMR (HSQC, HMBC, NOESY) methods. Neither compound showed significant inhibitory effects on butyrylcholinesterase (BuchE) and acetylcholinesterase (AChE), nor the selected tumor cells growth. Based on an online activity prediction program (PASS ONLINE), the structures with isoxazoline skeletons were found to show potential anti-asthmatic (AM) and anti-anaphylaxis (AP) activities; moreover, compounds 1 and 2 were predicted to possess high affinities for many enzymes involved in AM and AP according to the RCSB Protein Data Bank. High-affinity binding to phosphodiesterase IV (PDE-4), an important inflammatory modulator in asthma, was demonstrated experimentally, beside that, the predicted structures based on compounds 1 and 2 were analyzed for PDE-4 interactions using the molecular docking methodology of Discovery Studio 3.0 (DS 3.0). The predicted structure 2A-6 exhibited much higher affinity and stability of PDE-4 binding than the clinical PDE-4 inhibitor rolipram.

Phosphodiesterase 4 inhibitors for the treatment of chronic obstructive pulmonary disease: a review of current and developing drugs

INTRODUCTION

Phosphodiesterase (PDE) inhibitors modulate lung inflammation and cause bronchodilation by increasing intracellular cyclic adenosine 3', 5'-monophosphate in airway smooth muscle and inflammatory cells. Roflumilast is the only approved PDE-4 inhibitor (PDE4I) for use in chronic obstructive pulmonary disease (COPD). Its beneficial clinical effects occur preferentially in patients with chronic bronchitis and frequent COPD exacerbations. Use of roflumilast as adjunctive or alternate therapy to other COPD medications reduces exacerbations and modestly improves lung function.

AREAS COVERED

This article reviews the current role of PDE4I in COPD treatment emphasizing roflumilast's clinical efficacy and adverse effects. This article also reviews developing PDE4Is in early clinical trials and in preclinical studies.

EXPERT OPINION

After decades of research in drug development, PDE4Is are a welcomed addition to the COPD therapeutic armamentarium. In its current clinical role, the salubrious clinical effects of PDE4I in reducing exacerbations and stabilizing the frequent exacerbator phenotype have to be cautiously balanced with numerous adverse effects. Developing drugs may provide similar or better clinical benefits while minimizing adverse effects by changing the mode of drug delivery to inhaled formulations, combining dual PDE isoenzyme inhibitors (PDE1/4I and PDE3/4I) and by forming hybrid molecules with other bronchodilators (muscarinic receptor antagonist/PDE4I and β2-agonist/PDE4I).