Hipposudoric acid explained

Hipposudoric acid is a red pigment found in the skin secretions of the hippopotamus;^[1] although the secretions are often known as "blood sweat" (thus the name "hipposudoric", referring to "hippo sweat"), they are neither blood nor sweat.

Like its orange-colored analog norhipposudoric acid, hipposudoric acid functions both as a natural sunscreen and as an antimicrobial agent.^[2] It is derived from the oxidative dimerization of homogentisic acid.^[3]

It has been both widely and falsely reported that hipposudoric acid colors hippo milk pink. This is not the case; hippo milk is white or beige in color.^[4]

Notes and References

1. Pure Appl. Chem. . 79 . 4 . 507–517 . 2007 . 10.1351/pac200779040507 . Studies on the red sweat of the Hippopotamus amphibius . Kimiko Hashimoto . Yoko Saikawa . Masaya Nakata . 12944558 .
2. The red sweat of the hippopotamus . Yoko Saikawa . Kimiko Hashimoto . Teruyuki Komiya . Nature . 2004 . 429 . 6990 . 363 . 10.1038/429363a . 15164051 . 4404922 . free .
3. Properties of the enzyme responsible to the synthesis of hipposudoric and norhipposudoric acids, the pigments in the red sweat of the hippopotamus . Moriya Kai . Matsuura Masanori . Saikawa Yoko . Hashimoto Kimiko . Yamaguguchi Ayumu . Sakamoto Kazuhiro . Akihisa Narito . Hirata Hiroyoshi . Nippon Kagakkai Koen Yokoshu . 86 . 2 . 1314 . 2006 . 2009-04-11 . 2012-02-17 . https://web.archive.org/web/20120217004657/http://sciencelinks.jp/j-east/article/200618/000020061806A0436283.php . dead .
4. Web site: FACT CHECK: Is Hippopotamus Milk Pink?. 2022-02-16. Snopes.com. en-US.