Current Topics in Medicinal Chemistry - Volume 22, Issue 1, 2022

Abstract: Natural products have been proven as the main source of biologically active compounds, which are potentially useful for drug development. As one of the most studied pentacyclic triterpenes, oleanolic acid (OA) exhibits a broad range of biological activities and serves as a good scaffold for the development of novel derivatives that could be vital in drug discovery for various ailments. Till now, many of its derivatives with multiple bioactivities have been prepared through chemical modification. This review summarizes the recent reports of OA derivatives (2016-present) and their biological effects and action mechanisms in vitro and in vivo models, and discusses the design of novel and potent derivatives.

Abstract: Bacterial infections, which cause a wide range of host immune disorders leading to local and systemic tissue damage, are still one of the main causes of patient morbidity and mortality worldwide. Treatment of bacterial infections is challenging, mainly attributed to the rapidly evolving resistance mechanisms, creating an urgent demand to develop novel antibacterial agents. Hybridization is one of the most promising strategies in the development of novel antibacterial drugs with the potential to address drug resistance since different pharmacophores in the hybrid molecules could modulate multiple targets and exert synergistic effects. Isatin, distributed widely in nature, can exert antibacterial properties by acting on diverse enzymes, proteins, and receptors. Accordingly, hybridization of isatin pharmacophores with other antibacterial pharmacophores in one molecule may provide novel antibacterial candidates with broad-spectrum activity against various pathogens, including drug-resistant forms. This review aims to outline the recent advances of natural and synthetic isatin hybrids with antibacterial potential and summarizes the structure-activity relationship (SAR) to provide an insight for the rational design of more active candidates, covering articles published between January 2012 and June 2021.

Abstract: Staphylococcus aureus (S. aureus), a prominent, highly contagious nosocomial and community- acquired bacterial pathogen, can cause a broad spectrum of diseases. Antibiotic-resistant S. aureus strains, which pose potential causes of morbidity and mortality, have continuously emerged in recent years, calling for novel anti-S. aureus agents. 1,2,3-triazole and 1,2,4-triazole, the bioisostere of amides, esters, and carboxylic acids, are potent inhibitors of DNA gyrase, topoisomerase IV, efflux pumps, filamentous temperature-sensitive protein Z, and penicillin-binding protein. In particular, 1,2,3-triazole- and 1,2,4-triazole-containing hybrids have the potential to exert dual or multiple antibacterial mechanisms of action. Moreover, 1,2,3-triazole-cephalosporin hybrid cefatrizine, 1,2,3- triazole-oxazolidinone hybrid radezolid, and 1,2,4-triazolo[1,5-a]pyrimidine hybrid essramycin, have already been used in clinical practice to treat bacterial infections. Hence, 1,2,3-triazole- and 1,2,4- triazole-containing hybrids possess promising broad-spectrum antibacterial activity against diverse clinically significant organisms, including drug-resistant forms. This review is an update on the latest development of 1,2,3-triazole- and 1,2,4-triazole-containing hybrids with anti-S. aureus activity, covering articles published between January 2020 and July 2021.

Abstract: Gram-positive and Gram-negative pathogens are able to evade the host immune system, persist within the human host, and lead to severe disease and even death. At present, bacterial infections are one of the leading causes of morbidity and mortality across the world. The development of novel antibacterial agents still represents a challenging endeavor, which is mainly attributed to the continuous emergence of more virulent and drug-resistant pathogens. Benzofuran constitutes the core of diverse pharmacologically active compounds, and there are a variety of approved benzofuranbased drugs in the market or currently going through different clinical phases or registration statuses. Benzofurans could exert antibacterial activity through various mechanisms and possess pronounced activity; therefore, benzofuran is a useful skeleton for the discovery of novel antibacterial agents. This review focuses on the recent advancement of naturally occurring benzofuran derivatives and hybrids of benzofurans with other pharmacophores as antibacterial agents, covering articles published between January 2015 and July 2021. The chemical structures and structure-activity relationships are also discussed.