The discovery of new spirocyclic muscarinic M3 antagonists

Semi-supervised heterogeneous graph contrastive learning for drug-target interaction prediction

Identification of drug-target interactions (DTIs) is an important step in drug discovery and drug repositioning. In recent years, graph-based methods have attracted great attention and show advantages on predicting potential DTIs. However, these methods face the problem that the known DTIs are very limited and expensive to obtain, which decreases the generalization ability of the methods. Self-supervised contrastive learning is independent of labeled DTIs, which can mitigate the impact of the problem. Therefore, we propose a framework SHGCL-DTI for predicting DTIs, which supplements the classical semi-supervised DTI prediction task with an auxiliary graph contrastive learning module. Specifically, we generate representations for the nodes through the neighbor view and meta-path view, and define positive and negative pairs to maximize the similarity between positive pairs from different views. Subsequently, SHGCL-DTI reconstructs the original heterogeneous network to predict the potential DTIs. The experiments on the public dataset show that SHGCL-DTI has significant improvement in different scenarios, compared with existing state-of-the-art methods. We also demonstrate that the contrastive learning module improves the prediction performance and generalization ability of SHGCL-DTI through ablation study. In addition, we have found several novel predicted DTIs supported by the biological literature. The data and source code are available at: https://github.com/TOJSSE-iData/SHGCL-DTI.

Spirocyclic Scaffolds in Medicinal Chemistry

Spirocyclic scaffolds are incorporated in various approved drugs and drug candidates. The increasing interest in less planar bioactive compounds has given rise to the development of synthetic methodologies for the preparation of spirocyclic scaffolds. In this Perspective, we summarize the diverse synthetic routes to obtain spirocyclic systems. The impact of spirocycles on potency and selectivity, including the aspect of stereochemistry, is discussed. Furthermore, we examine the changes in physicochemical properties as well as in in vitro and in vivo ADME using selected studies that compare spirocyclic compounds to their nonspirocyclic counterparts. In conclusion, the value of spirocyclic scaffolds in medicinal chemistry is discussed.

Spiropiperidine Sultam and Lactam Templates: Diastereoselective Overman Rearrangement and Metathesis followed by NH Arylation

We report the diastereoselective synthesis of novel spiropiperidine templates for use in SAR studies of β-secretase (BACE) inhibitors and also as versatile ligands for other receptor types. The overall synthetic approach stems from chiral starting material benzyl (S)-2-methyl-4-oxopiperidine-1-carboxylate and employs an Overman rearrangement to control the stereochemistry at the quaternary center. This process is followed by a Grubbs metathesis to close a five-membered "top" ring to form an α,β-unsaturated lactam or an α,β-unsaturated sultam. We also demonstrate that this chemistry can accommodate additional substituents on the lactam/sultam ring and allows late stage sequential functionalization of the amine and amide nitrogens to rapidly produce diverse analogues.

Evaluation of WO-2012085582 and WO-2012085583 two identified MABAs: backups to AZD-2115?

These two patent applications each claim combination formulations comprising a single dual-acting muscarinic antagonist/beta 2 agonist (MABA), as a free base or salt, with a second class of drug and the use of these formulations for the treatment of asthma and COPD. The two specified compounds are close analogues of each other and were originally disclosed in the same patent application. They are, respectively, 3-(2-chloro-3-((4-(2-ethylthiazole-4-carbonyl)-1-oxa-4,9-diazaspiro[5.5]undecan-9-yl)methyl)phenethoxy)-N-cyclopentyl-N-(2-(2-(5-hydroxy-3-oxo-3,4-dihydro-2H-benzo[b]{1,4] oxazin-8-yl)ethylamino)ethyl)propanamide and N-butyl-N-(2-(2-(5-hydroxy-3-oxo-3,4-dihydro-2H-benzo[b][l,4]oxazin-8-yl)ethylamino)ethyl)-3-(3-(2-(4-(2-isopropylthiazole-4-carbonyl)-1-oxa-4,9-diazaspiro[5.5]undecan-9-yl)ethyl)phenethoxy)propanamide.

Inhaled long-acting muscarinic antagonists in chronic obstructive pulmonary disease

In 2002, the first long-acting muscarinic antagonist, tiotropium bromide (Spiriva®), was launched as a once-daily bronchodilating agent for the treatment of chronic obstructive pulmonary disease. Since then, there has been intense discovery research activity in this area and, currently, several alternative inhaled long-acting muscarinic antagonists are reported under clinical development by several pharmaceutical companies. This article will review the current inhaled development candidates, as well as literature reports of the most significant preclinical chemical series specifically designed as inhaled antimuscarinic agents.