Widely distributed in plants, usually in the form of complex polysaccharides. Also in mycobacteria. Isoln from mesquite gum: Anderson, Sands, J. Am. Chem. Soc. 48, 3172 (1926); Org. Synth. coll. vol. I, 16 (2nd ed., 1941); White, J. Am. Chem. Soc. 69, 715 (1947); from western red cedar (Thuja plicata Don., Cupressaceae): Anderson, Erdtman, ibid. 71, 2927 (1949); from sapote gum: White, ibid. 75, 257 (1953); from heartwood of port orford cedar (Chamaecyparis lawsoniana (Murr.) Parl, Cupressaceae): Kritchevsky, Anderson, ibid. 77, 3391 (1955). Structure: Wolfrom, Christman, ibid. 58, 39 (1936). Synthesis: Hough, Jones, J. Chem. Soc. 1951, 1122.