Synthesis and evaluation of cyclohexane carboxylic acid head group containing isoxazole and thiazole analogs as DGAT1 inhibitors

Design, Synthesis, and Antifungal Evaluation of Diverse Heterocyclic Hydrazide Derivatives as Potential Succinate Dehydrogenase Inhibitors

Plant pathogenic fungi pose a significant threat to agricultural production, necessitating the development of new and more effective fungicides. The ring replacement strategy has emerged as a highly successful approach in molecular design. In this study, we employed the ring replacement strategy to successfully design and synthesize 32 novel hydrazide derivatives containing diverse heterocycles, such as thiazole, isoxazole, pyrazole, thiadiazole, 1,3,4-oxadiazole, 1,2,4-oxadiazole, thiophene, pyridine, and pyrazine. Their antifungal activities were evaluated in vitro and in vivo. Bioassay results revealed that most of the title compounds displayed remarkable antifungal activities in vitro against four tested phytopathogenic fungi, including Fusarium graminearum, Botrytis cinerea, Sclerotinia sclerotiorum, and Rhizoctonia solani. Especially, compound 5aa displayed a broad spectrum of antifungal activity against F. graminearum, B. cinerea, S. sclerotiorum, and R. solani, with the corresponding EC50 values of 0.12, 4.48, 0.33, and 0.15 μg/mL, respectively. In the antifungal growth assay, compound 5aa displayed a protection efficacy of 75.5% against Fusarium head blight (FHB) at a concentration of 200 μg/mL. In another in vivo antifungal activity evaluation, compound 5aa exhibited a noteworthy protective efficacy of 92.0% against rape Sclerotinia rot (RSR) at a concentration of 100 μg/mL, which was comparable to the positive control tebuconazole (97.5%). The existing results suggest that compound 5aa has a broad-spectrum antifungal activity. Electron microscopy observations showed that compound 5aa might cause mycelial abnormalities and organelle damage in F. graminearum. Moreover, in the in vitro enzyme assay, we found that the target compounds 5aa, 5ab, and 5ca displayed significant inhibitory effects toward succinate dehydrogenase, with the corresponding IC50 values of 1.62, 1.74, and 1.96 μM, respectively, which were superior to that of boscalid (IC50 = 2.38 μM). Additionally, molecular docking and molecular dynamics simulation results revealed that compounds 5aa, 5ab, and 5ca have the capacity to bind in the active pocket of succinate dehydrogenase (SDH), establishing hydrogen-bonding interactions with neighboring amino acid residues.

Sustainable Aerobic Bromination with Controllable Chemoselectivity

The formation of C-Br(s) is one of the most fundamental reactions in organic synthesis. Oxidative bromination is a "green" way to achieve it. Aerobic bromination has drawn great interest in the past decades, while the poor substrate scope and selectivity, low efficiency, and the use of metal catalyst still confine its application. In this article, we establish a transition-metal-free aerobic bromination promoted by ionic liquid in a catalytic amount with controllable chemoselectivity toward numbers of C-Br(s) formed, and both NaBr/AcOH and HBr(aq) could be used as the bromine source. This methodology shows high efficiency and has a broad substrate scope for various kinds of C-H(s). We also validate this system by the gram-scale (one-pot) synthesis of functional molecules and direct recycle of the catalyst. The possible radical pathway of this catalysis is also presented with evidence.

How lipid droplets "TAG" along: Glycerolipid synthetic enzymes and lipid storage

Triacylglycerols (TAG) serve as the predominant form of energy storage in mammalian cells, and TAG synthesis influences conditions such as obesity, fatty liver, and insulin resistance. In most tissues, the glycerol 3-phosphate pathway enzymes are responsible for TAG synthesis, and the regulation and function of these enzymes is therefore important for metabolic homeostasis. Here we review the sites and regulation of glycerol-3-phosphate acyltransferase (GPAT), acylglycerol-3-phosphate acyltransferase (AGPAT), lipin phosphatidic acid phosphatase (PAP), and diacylglycerol acyltransferase (DGAT) enzyme action. We highlight the critical roles that these enzymes play in human health by reviewing Mendelian disorders that result from mutation in the corresponding genes. We also summarize the valuable insights that genetically engineered mouse models have provided into the cellular and physiological roles of GPATs, AGPATs, lipins and DGATs. Finally, we comment on the status and feasibility of therapeutic approaches to metabolic disease that target enzymes of the glycerol 3-phosphate pathway. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.

Discontinued drug therapies to treat diabetes in 2014

INTRODUCTION

Available drugs partially attenuate the hyperglycemia characteristic of diabetes. However, successful approaches to treat the root cause or to cure or prevent diabetes remain elusive. Drug discovery and development programs continue to focus on mechanisms that impact specific symptoms of diabetes. In 2014, programs were discontinued for a variety of reasons and these discontinued programs are discussed herein.

AREAS COVERED

A search of discontinued products in the metabolic area for 2014 identified mostly compounds that were being developed to treat diabetes (mostly type 2 diabetes). Candidates were identified through the use of PharmaProjects. The author also sought information using Google, PubMed, HighWire and ClinicalTrials.gov. The discontinued development programs that were identified were not numerous as in previous years and so they are presented here without segregation into categories.

EXPERT OPINION

In general, the specific reasons for the discontinuation of these programs have not been clearly disclosed. In some cases, business considerations are given, whereas in others, there are specific safety issues that emerged which were not expected from nonclinical experience. In the final analysis, it is clear that all of these programs have been discontinued because the evidence does not favor the type of efficacy and risk:benefit ratio that justifies additional expenditures. There remains a clear need for precise addressable mechanisms to affect the root causes of diabetes.