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
Castor and Pollux (Prado) into the Prado (catalogue number Catalogue Nr. E.28). The erroneous identification with Antinous generated high interest in the sculpture, with large numbers of copies being produced, largely made in Italy and Northern Europe and based on plaster casts rather than made in Spain and based on the original there. These inevitably stoked the interest by obscuring the fact that the Antinous head was in fact a restoration, instead smoothing the two into a meaningful whole (as did the casts on which they were based). Main site about copies of the Ildefonso (or Castor & Pollux) group : http://www.antinoos.info/copies1.htm Copies Castor