title: Pigment chemistry: the red sweat of the hippopotamus.
abstract: 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.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Saikawa
authors.forename: Kimiko
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Masaya
authors.initials: M
authors.lastname: Nakata
authors.forename: Masato
authors.initials: M
authors.lastname: Yoshihara
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Nagai
authors.forename: Motoyasu
authors.initials: M
authors.lastname: Ida
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Komiya
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000737:chemistry; D001704:Biopolymers / Q000032:analysis / Q000737:chemistry; D003116:Color; D009682:Magnetic Resonance Spectroscopy; D008322:Mammals / Q000502:physiology*; D015394:Molecular Structure; D009093:Mucus / Q000737:chemistry / Q000378:metabolism; D010860:Pigments, Biological / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D012867:Skin / Q000378:metabolism; D013473:Sunscreening Agents / Q000032:analysis / Q000737:chemistry; D013542:Sweat / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001704:Biopolymers; D010860:Pigments, Biological; D013473:Sunscreening Agents