Synthesis and antifungal activity of novel streptochlorin analogues

•A series of novel indole-modified analogues of streptochlorin were synthesized.•Streptochlorin analogues were screened against seven phytopathogenic fungi.•Some compounds showed good antifungal activity in primary assays.•The SAR of the streptochlorin analogues were summarized.

Streptochlorin, first isolated as a new antibiotic in 1988 from the lipophilic extracts of the mycelium of a Streptomyces sp, is an indole natural products with a variety of biological activities. Based on the methods developed for the synthesis of pimprinine in our laboratory, we have synthesized a series of indole-modified streptochlorin analogues and measured their activities against seven phytopathogenic fungi. Some of the analogues displayed good activity in the primary assays, and the seven compounds 10b, 10c, 11e, 13e, 21, 22c and 22e (shown in Figure 1) were identified as the most promising candidates for further study. Structural optimization is still ongoing with the aim of discovering synthetic analogues with improved antifungal activity.

Graphical abstractA series of novel streptochlorin analogues were designed and synthesized by modifying the indole moiety. Antifungal activity screening against seven phytopathogenic fungi led to the identification of seven compounds as the most promising candidate for further study.Figure optionsDownload full-size imageDownload as PowerPoint slide