Antimicrobials natural product-derived

The indole derivative 12, a synthetic analogue of the antimicrobial natural product chuangxinmycin, is an inhibitor of bacterial tryptophanyl tRNA synthetase and displays antibacterial activity <2002BML3171>. 

Contraction in the number of EPA-allowed biocides has heightened efforts to develop naturally derived preservatives and microorganisms capable of countering microbial degradation. Neem oil A. dirachta indica seed extract) has been featured as an exceptional natural candidate for the preservation of cosmetic products. Naturally derived chemicals with antimicrobial properties have been used since antiquity as preservatives. However, displacement of successhil synthetic products by natural products in preservatives of any category remains to be witnessed. 

The majority of indolocarbazole alkaloids, isolated so far from nature, are derivatives of the indolo[2,3-fl]pyrrolo[3,4-c]carbazole ring system 292. They have been isolated from soil organisms, slime molds, and marine sources (3,7,8,252-255), and have shown a broad range of potent biological activities, such as antifungal, antimicrobial, antitumor, and antihypertensive activity (3,7,256-260,267-270). Their activity as potent inhibitors of protein kinase C (PKC) has received special attention, and was the focus of several investigations (8,257,258,271-280). The history of these natural products dates back about 30 years (Scheme 2.73). 

Abstract Heterocyclic structures are an integral part of numerous drugs and natural products and there is a considerable interest in efficient methods for their S3mthesis. A variety of multicomponent reactions (MCRs) provide access to heterocychc structures such as isocyanide based MCRs, dicarbonyl derivative and cycloaddition MCRs. MCR-derived heterocycles are typically prepared in few, versatile and atom efficient synthetic steps and exhibit anticancer, antioxidant and antimicrobial properties. 

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