Daiki Katagishi

COVID-19 is an ongoing worldwide pandemic. Even today, there is a need for the development of effective therapeutic agents. SARS-CoV-2 is known as the causative virus of COVID-19, and its main protease is one of the enzymes essential for its growth and is considered a drug discovery target. In this study, we evaluated the inhibitory activities of a variety of fullerene derivatives, including newly synthesized derivatives, against the main protease of SARS-CoV-2. As a result, the malonic acid-type fullerene derivatives showed the strongest inhibitory activity.

Aberrant hyperactivation of nuclear factor erythroid 2-related factor 2 (Nrf2) has been reported in non-small cell lung cancer through overexpression of the p62/sequestosome1 protein, resulting in the acquisition of malignancy and drug resistance. We previously discovered compounds termed K67 and KOA153 that overcome chemotherapy resistance in human hepatocellular carcinoma cell lines by inhibiting the protein–protein interactions between p62 and Kelch-like ECH-associated protein 1 (Keap1), an Nrf2 suppressor. Herein, we synthesized analogs of K67 and KOA153 and investigated their potential as doxorubicin sensitizers against a human non-small cell lung cancer A549 cell line that is addicted to Nrf2 via overexpression of p62. KOA153 and the newly synthesized amide compounds exhibited significant doxorubicin-sensitizing activity without cytotoxicity. In addition, dimethylamide derivatives activated Nrf2 in HEK293 cells expressing normal levels of p62. Therefore, dimethylamide derivatives are likely novel type of anticancer agents.