Papain

Papain
Papain is an enzyme that you can find in the leaves of the papaya plant, (Carica papaya) that aids/catalyzes the breakdown of proteins through the catabolic reaction hydrolysis. Depending if you extracted the enzyme from and female versus male tree determines the abundance of crude papain and how active it is.  In this case female trumphs males.The environment in which this enzyme is active is in a pH environment of around 6.0-8.0, and functions at temperatures higher than human body temperature.

Since papain can come in different forms, it also can be found in a wide spectrum of products. For instance it can be used to clarify beer, a meat tenderiser, cosmetics, toothpaste, contact lens cleanser or even wool treatment.  That said I think that papain use for medical purposes are the most impactful. You can find papain in ointments that treat pain or swelling, much as like insect bites. It can also be used as a digestive aid for treating parasitic worms, shingles symptoms or even runny noses.  Because of it's basic function of a protease papain is plays a hand in many of our everyday necessities.

In the picture above, I have circled the two chiral centers and written the standard molecular formula of this compound. 

Functional Groups Found: Ketone, Amine, Hydroxyl, Carboxyl

Sources:

http://www.webmd.com/vitamins-supplements/ingredientmono-69-papain.aspx?activeingredientid=69&activeingredientname=papain

http://www.biotechlearn.org.nz/themes/biotech_at_home/fruit_enzyme_uses

http://www.britannica.com/EBchecked/topic/441803/papain

http://www.enzymedica.com/education/enzyme-faqs.html