Red Hippopotamus Sweat

Hippos have developed a very interesting form of sweat that possesses additional functionality than cooling down the body temperature. Before studied, the sweat was thought to be blood due to the red colour, but it was found to just be two pigmented molecules which have two functions for the hippo, being a sunscreen, and an antibiotic. It has been found that the main components aren't secreted as most sweat components are, but secreted in subdermal glands, making the classification of the sweat false as sweat is secreted from sweat glands, located in the epidermis.

The two molecules that are secreted are Hipposudoric acid and Norhipposudoric acid (seen below)

Hipposudoric acid

Norhipposudoric acid

These molecules are conjugated systems, meaning in layman's terms that the bonds alternate single to double, but this also means that light is absorbed into this system ranging from the 200nm - 600nm wavelength.  This property is what gives the sweat the sunscreen-like properties and the red colour where the Hipposudoric acid is red and the Norhipposudoric acid is orange.  As for the antibiotic properties, this is the job of Hipposudoric acid, which inhibits two species of pathogenic bacteria Pseudomonas aeruginosa and Klebsiella pneumoniae.

In finding this, there is an obvious potential for this to be used in consumer sunscreens as there is such a demand for natural sources in cosmetics. Now it's not like there would be a farm somewhere collecting hippo sweat, as there is a method for synthesizing Hipposudoric acid, published in 2006 in Tetrahedron Letters.

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