Synthesis and molecular docking of new roflumilast analogues as preferential-selective potent PDE-4B inhibitors with improved pharmacokinetic profile

Advances in the development of phosphodiesterase-4 inhibitors

Phosphodiesterase 4 (PDE4) hydrolyzes cyclic adenosine monophosphate (cAMP) and plays a vital roles in many biological processes. PDE4 inhibitors have been widely studied as therapeutics for the treatment of various diseases, including asthma, chronic obstructive pulmonary disease (COPD) and psoriasis. Many PDE4 inhibitors have progressed to clinical trials and some have been approved as therapeutic drugs. Although many PDE4 inhibitors have been approved to enter clinical trials, however, the development of PDE4 inhibitors for the treatment of COPD or psoriasis has been hampered by their side effects of emesis. Herein, this review summarizes advances in the development of PDE4 inhibitors over the last ten years, focusing on PDE4 sub-family selectivity, dual target drugs, and therapeutic potential. Hopefully, this review will contribute to the development of novel PDE4 inhibitors as potential drugs.

Synthesis of 3-carene-derived nanocellulose/1,3,4-thiadiazole-amide complexes with antifungal activity for plant protection

BACKGROUND

Nanopesticides have been proved to be a powerful and promising tool to solve the issues in agriculture. The purpose of the present study was to develop ecofriendly nanopesticide systems by the strategy of comprehensive utilization of two natural biomass resources (bagasse and turpentine oil) because of their incomparable advantages.

RESULTS

In this research, a series of nanocellulose carriers ETOCN-1-ETOCN-4 (ETOCN, esterified TEMPO-oxidized cellulose nanofibers) with different degrees of substitution were prepared and characterized by Fourier-transform infrared (FTIR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Then, 21 1,3,4-thiadiazole-amide compounds 8a-8u containing gem-dimethylcyclopropane ring were designed, synthesized and characterized. A preliminary bioassay indicated that compound 8i (R = p-Br Ph) exhibited broad-spectrum antifungal activity against the tested fungi. Furthermore, drug-loading complexes 8i/ETOCN-1-8i/ETOCN-4 were fabricated by integration of nanocellulose-based carriers ETOCN-1-ETOCN-4 with bioactive compound 8i, and the drug-loading capacities, microstructures and sustained-releasing performance of these complexes were also investigated. According to the observation of scanning electron microscopy (SEM) images of complex 8i/ETOCN-2, the small-molecule drug and the carrier formed a well-distributed and compact complex, which led to the excellent drug-loading capacity and sustained-releasing performance in the ethanol/water (1:1, v/v) system.

CONCLUSIONS

Complexes 8i/ETOCN-1-8i/ETOCN-4 deserved further study as the promising candidates for the development of nanopesticides. © 2022 Society of Chemical Industry.

Insight on a new indolinone derivative as an orally bioavailable lead compound against renal cell carcinoma

A series of novel 3-indolinone-thiazolidinones and oxazolidinones 4a-k was synthesized via molecular hybridization approach and sequentially evaluated to explore its cytotoxic activity. The cytotoxicity screening pointed toward the N-cyclohexyl thiazolidinone derivative 4f that revealed promising renal cytotoxicity against CAKI-1 and UO-31 renal cancer cell lines with IC₅₀ values 4.74 and 3.99 µM, respectively, which were comparable to those of sunitinib along with good safety threshold against normal renal cells. Further emphasis on compound 4f renal cytotoxicity was achieved via different enzyme assays and CAKI-1 and UO-31 cell cycle analysis. The results were supported by in silico studies to explore its physicochemical, pharmacokinetic and drug-likeness properties. Finally, compound 4f was subjected to an in vivo pharmacokinetic study through two different routes of administration showing excellent oral bioavailability. This research represents compound 4f as a promising candidate against renal cell carcinoma.

Synthesis, antifungal activity and 3D-QSAR study of novel acyl thiourea compounds containing gem-dimethylcyclopropane ring

A series of novel acyl thiourea compounds containing gem-dimethylcyclopropane ring were designed and synthesized by multi-step reactions in search of novel antifungal molecules. Structures of all the target compounds were characterized by spectral techniques of UV-vis, FT-IR, ¹H-NMR, ¹³C-NMR, and ESI-MS. The antifungal activity of the target compounds was preliminarily evaluated by agar dilution method. The antifungal bioassay revealed that, at 50 μg/mL, compounds 5h (R = o-F), 5m (R = p-Br), and 5n (R = o-NO₂) showed the same antifungal activity of 73.6% against Physalospora piricola, which was comparable than that of the positive control. Furthermore, against Gibberella zeae, compounds 5k (R = m-Cl), 5l (R = m-Br), 5m (R = p-Br), and 5n (R = o-NO₂) displayed the same antifungal activity of 75.6%, and compound 5o (R = p-NO₂) displayed antifungal activity of 78.8%, which were all better than that of the positive control. The preliminary analysis of 3D-QSAR model was performed to study the effect of molecular structure on biological activity using the comparative molecular field analysis (CoMFA) method. The results showed 3D-QSAR model (r² = 0.995, q² = 0.503) was reasonable and effective.

Why new biology must be uncovered to advance therapeutic strategies for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by the destruction of alveolar tissue (in emphysema) and airway remodeling (leading to chronic bronchitis), which cause difficulties in breathing. It is a growing public health concern with few therapeutic options that can reverse disease progression or mortality. This is in part because current treatments mainly focus on ameliorating symptoms induced by inflammatory pathways as opposed to curing disease. Hence, emerging research focused on upstream pathways are likely to be beneficial in the development of efficient therapeutics to address the root causes of disease. Some of these pathways include mitochondrial function, cytoskeletal structure and maintenance, and airway hydration, which are all affected by toxins that contribute to COPD. Because of the complexity of COPD and unknown targets for disease onset, simpler model organisms have proved to be useful tools in identifying disease-relevant pathways and targets. This review summarizes COPD pathology, current treatments, and therapeutic discovery research, with a focus on the aforementioned pathways that can advance the therapeutic landscape of COPD.

The long and winding road of designing phosphodiesterase inhibitors for the treatment of heart failure

Cyclic nucleotide phosphodiesterases (PDEs) are a superfamily of enzymes known to play a critical role in the indirect regulation of several intracellular metabolism pathways through the selective hydrolysis of the phosphodiester bonds of specific second messenger substrates such as cAMP (3',5'-cyclic adenosine monophosphate) and cGMP (3',5'-cyclic guanosine monophosphate), influencing the hypertrophy, contractility, apoptosis and fibroses in the cardiovascular system. The expression and/or activity of multiple PDEs is altered during heart failure (HF), which leads to changes in levels of cyclic nucleotides and function of cardiac muscle. Within the cardiovascular system, PDEs 1-5, 8 and 9 are expressed and are interesting targets for the HF treatment. In this comprehensive review we will present a briefly description of the biochemical importance of each cardiovascular related PDE to the HF, and cover almost all the "long and winding road" of designing and discovering ligands, hits, lead compounds, clinical candidates and drugs as PDE inhibitors in the last decade.

Simultaneous quantification and pharmacokinetic evaluation of roflumilast and its N-oxide in cynomolgus monkey plasma by LC-MS/MS method

Roflumilast (ROF), a nonsteroidal anti-inflammatory drug, has successfully been used to treat systemic and pulmonary inflammation associated with chronic obstructive pulmonary disease. To evaluate its pharmacokinetics in monkeys, a sensitive, rapid and reliable liquid chromatography with tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of ROF and its N-oxide metabolite (RNO). The mobile phase contained 0.1% formic acid aqueous solution (A) and 0.1% formic acid acetonitrile solution (B). All monkey plasma samples were pretreated using protein precipitation with methanol-acetonitrile (50:50, v/v) in 50 μl plasma samples. Chromatographic separation was performed with mass spectral acquisition performed in positive electrospray ionization, utilizing multiple reaction monitoring. This method was successfully applied to a pharmacokinetic study in cynomolgus monkeys. Following administration of a single oral dose of 1 mg/kg ROF in monkeys, pharmacokinetic data for ROF and RNO was reported for the first time. After oral administration, ROF was rapidly absorbed and metabolized to its metabolite RNO. The mean area under the curve value of RNO was ~13 times larger than that of ROF, suggesting that most ROF was metabolized to RNO in cynomolgus monkeys.

Synthesis and biological evaluation of new prodrugs of etodolac and tolfenamic acid with reduced ulcerogenic potential

Gastric irritation and ulcerogenic effect of the acidic NSAIDs are of the most challenging problems in designing novel anti-inflammatory agents. In this study, the new prodrugs were prepared through Steglich esterification reaction between the carboxylic acid functional group of etodolac or tolfenamic acid and thymol. The structures were confirmed by IR, ¹H NMR, ¹³C NMR, mass spectroscopy and elemental analysis. Their chemical stability in addition to a kinetic study of their hydrolysis in 20% liver homogenate and 10% buffered plasma were investigated. In vitro enzymatic hydrolysis showed half-life times 88.84 and 106.61 min for the prodrugs of etodolac and tolfenamic acid, respectively. Their ability to inhibit paw edema and their ulcerogenic potential were assessed in rats and compared to their parent drugs. the prodrugs were found to be stable in different pHs at room and body temperatures. Both prodrugs proved to possess high percentage of inhibition of paw edema (94.68 & 97.1%) in rats comparable to that of the parent drugs (90.33 & 93.23%) and, most importantly with lower ulcerogenic potential. The prodrugs are expected to be converted to their parent drugs rapidly in plasma and liver in vivo and proved to be safer than their parent drugs. The study opens a perspective chance that can be a backbone for further investigations.