toyocamycin

Toyocamycin is a naturally occurring nucleoside antibiotic and adenosine analog first isolated from Streptomyces toyocaensis. It exhibits diverse biological activities, including anticancer, antifungal, and antiviral properties. Toyocamycin acts primarily by mimicking adenosine and disrupting RNA synthesis—being incorporated into RNA during transcription—which blocks or disrupts RNA production and ribosome function. It also inhibits the maturation of ribosomal RNA (rRNA), affecting protein synthesis. Additionally, toyocamycin is a potent inhibitor of the IRE1α-XBP1 pathway in the unfolded protein response (UPR), blocking XBP1 mRNA splicing without affecting other UPR branches such as ATF6 or PERK. Other mechanisms include inhibition of phosphatidylinositol kinase (a cell proliferation regulator) and cyclin-dependent kinases such as CDK9. Toyocamycin has shown cytotoxicity against multiple myeloma cells—including bortezomib-resistant lines—and activity against Candida albicans due to selective uptake via nucleoside transporters[1][2][5].

Brand names

Vengicide

Other names

4-amino-5-cyano-7-(D-ribofuranosyl)-7H-pyrrolo(2,3-d)pyrimidine7-deaza-7-cyanoadenosineAhygroscopin-BCyanotubericidinSiromycinUramycin BUnamycin B