Antibacterial Evaluation of Novel Substituted Cycloheptaindoles in Staphylococcus and Enterococcus Strains

Synthesis and Structure–Activity Analysis of Novel Potential Antifungal Cyclotryptamine Alkaloid Derivatives

A total of 39 novel cyclotryptamine alkaloid derivatives were prepared from 2-(1H-indol-3-yl) acetonitrile. The prepared compounds were evaluated against six plant pathogen fungi. Bioassay results revealed that most of the compounds displayed higher in vitro antifungal activities than the positive control. Notably, compound b2 displayed the broadest and most effective activity among the tested cyclotryptamine alkaloid derivatives and might be a novel potential leading compound for further development as an antifungal agent.

Synthesis and antifungal activity of novel chiral indole analogues

Starting from L-tryptophan, 19 new N-substituted chiral indole analogs were synthesized. The prepared compounds were evaluated for biological activity against Sclerotinia sclerotiorum, Alternaria solani, Verticillium dahliae, Colletotrichum orbiculare, Cytospora juglandis and Curvularia lunata. The preliminary bioassays showed that most of the synthesized compounds exhibited fungicidal activity. Compound b13 in particular exhibited significant antifungal activity against Verticillium dahliae and Sclerotinia sclerotiorum, with the MIC value of 1.95 µg mL^-1. Compound b13 also showed excellent activity against six plant pathogen fungi, and was identified as the most active on the biological assays, and will be studied further.

Recent advances in indole dimers and hybrids with antibacterial activity against methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA), one of the major and most dangerous pathogens in humans, is a causative agent of severe pandemic of mainly skin and soft tissue and occasionally fatal infections. Therefore, it is imperative to develop potent and novel anti-MRSA agents. Indole derivatives could act against diverse enzymes and receptors in bacteria, occupying a salient place in the development of novel antibacterial agents. Dimerization and hybridization are common strategies to discover new drugs, and a number of indole dimers and hybrids possess potential antibacterial activity against a panel of clinically important pathogens including MRSA. Accordingly, indole dimers and hybrids are privileged scaffolds for the discovery of novel anti-MRSA agents. This review outlines the recent development of indole dimers and hybrids with a potential activity against MRSA, covering articles published between 2010 and 2020. The structure-activity relationship and the mechanism of action are also discussed to facilitate further rational design of more effective candidates.