Two cytotoxic squalene-derived polyethers from the Japanese red alga Chondria armata

Abstract

The red alga Chondria armata is known to produce and contain a rich diversity of secondary metabolites, such as domoic acid-related alkaloids and triterpene polyethers. Our investigation on red alga C. armata from Kagoshima coast, Japan, resulted in the isolation of two new triterpene polyethers, bandokorols A (1) and B (2). The structures of these compounds were determined based on spectroscopic data such as infrared (FTIR), ¹H-NMR, APT, ¹H–¹H-COSY, HSQC, HMBC, NOESY and FAB mass spectrometry (HRFABMS). The anticancer potentials of these compounds were tested against adult T-cell leukaemia (ATL), S1T cells and their IC₅₀ values are reported here.

Graphical Abstract

Keywords:

• Chondria armata
• Rhodomelaceae
• red alga
• cytotoxicity
• triterpenoids
• adult T-cell leukemia
• S1T

Acknowledgements

We are grateful to Dr. Takeshi YASUMOTO (Japan Food Research Laboratories), Dr. Nobuhiro FUSETANI (Fisheries and Oceans Hakodate), Dr. Takenori KUSUMI (Tokyo Institute of Technology), Dr. Ryuta TERADA (Kagoshima University) and Dr. Osamu ARAKAWA (Nagasaki Univ.) for helpful comments and encouragement. We are thankful to the Research Center for the Pacific Islands at Kagoshima University for providing the opportunity to survey Yakushima Island.

Disclosure statement

The authors declare no conflicts of interest.

Additional information

Funding

This work was supported financially by the Cooperative Research Program of the “Network Joint Research Centre for Materials and Devices” (No. 20181302 and 20191349), and the Grants-in-Aid for Scientific Research (No. 18K06732 and 17K05838) and the “Establishment of Research and Education Network on Biodiversity and Its Conservation in the Satsunan Islands” project of Kagoshima University adopted by the Ministry of Education, Culture, Sports, Science and Technology, Japan.