Castoreum a tincture in some perfumes and as a food additive. The government of Ontario pays trappers to harvest beaver castor sacs. The sacs brought between 2.62 - 5.10 Canadian dollars per ounce when auctioned at the May–June 2016 North American Fur Auction. At least 24 compounds are known constituents of beaver castoreum. Some of these have pheromonal activity. These are the phenols 4-ethylphenol and 1,2-dihydroxybenzene (catechol) and the ketones acetophenone and 3-hydroxyacetophenone. Five additional compounds noted are 4-methyl-1,2-dihydroxybenzene (4-methylcatechol), 4-methoxyacetophenone, 5-methoxysalicylic acid, salicylaldehyde, and 3-hydroxybenzoic acid. Other neutral compounds are oxygen-containing monoterpenes such as 6-methyl-l-heptanol, 4,6-dimethyl-l-heptanol, isopinocamphone, pinocamphone, two linalool
Ground substance as hyaluronic acid, heparan sulfate, dermatan sulfate, and chondroitin sulfate, proteoglycans which GAGs are bound to, and glycoproteins. Components of the ground substance are secreted by fibroblasts. Usually it is not visible on slides, because it is lost during staining in the preparation process. Link proteins such as vinculin, spectrin and actomyosin stabilize the proteoglycans and organize elastic fibers in the ECM. Changes in the density of ground substance can allow collagen fibers to form aberrant cross-links. Loose connective tissue is characterized by few fibers and cells, and a relatively large amount of ground substance. Dense connective tissue has a