Pigment chemistry: the red sweat of the hippopotamus.

Yoko Saikawa, Kimiko Hashimoto, Masaya Nakata, Masato Yoshihara, Kiyoshi Nagai, Motoyasu Ida, Teruyuki Komiya

Research output: Contribution to journalArticle


Within a few minutes of perspiration, the colourless, viscous sweat of the hippopotamus gradually turns red, and then brown as the pigment polymerizes. Here we isolate and characterize the pigments responsible for this colour reaction. The unstable red and orange pigments turn out to be non-benzenoid aromatic compounds that are unexpectedly acidic and have antibiotic as well as sunscreen activity.

Original languageEnglish
Pages (from-to)363
Number of pages1
Issue number6990
Publication statusPublished - 2004 May 27


ASJC Scopus subject areas

  • General

Cite this

Saikawa, Y., Hashimoto, K., Nakata, M., Yoshihara, M., Nagai, K., Ida, M., & Komiya, T. (2004). Pigment chemistry: the red sweat of the hippopotamus. Nature, 429(6990), 363.