Catechol one of the main natural phenols in argan oil and is a component of castoreum, a substance from the castor gland of beavers, used in perfumery. It is also found in "Agaricus bisporus". Catechol moieties are also found widely within the natural world. Arthropod cuticle consists of chitin linked by a catechol moiety to protein. The cuticle may be strengthened by cross-linking (tanning and sclerotization), in particular, in insects, and of course by biomineralization. Catechols such as DHSA are produced through the metabolism of cholesterol by bacteria such as "Mycobacterium tuberculosis". Urushiols are naturally existing organic compounds that have the
Pith and substance Pith and substance Pith and substance is a legal doctrine in Canadian constitutional interpretation used to determine under which head of power a given piece of legislation falls. The doctrine is primarily used when a law is challenged on the basis that one level of government (be it provincial or federal) has encroached upon the exclusive jurisdiction of another level of government. The Constitution Act, 1867, which established a federal constitution for Canada, enumerated in Sections 91 and 92 the topics on which the Dominion and the Provinces could respectively legislate. Notwithstanding that the lists were framed so as to