1355. β-Boswellic Acid
Nomenclature
CAS number: 631-69-6
(3α,4β)-3-Hydroxyurs-12-en-23-oic acid. C30H48O3; mol wt 456.70.
C 78.90%, H 10.59%, O 10.51%.
Description and references
Occurs as the acetate in frankincense (olibanum) from Boswellia carterii, Burseraceae. The β-form is predominant and is accompanied by small amounts of α- and γ-boswellic acid. Isoln from olibanum tears: Winterstein, Stein, Z. Physiol. Chem. 208, 9 (1932). Early structural studies: Simpson, Williams, ibid. 1938, 686, 1712; Ruzicka, Wirz, Helv. Chim. Acta 22, 948 (1939); 23, 132 (1940); Ruzicka et al., ibid. 27, 1859 (1944). Revised structure and stereochemistry: Beton et al., J. Chem. Soc. 1956, 2904; Allan, Chimia 17, 382 (1963); idem, Phytochemistry 7, 963 (1968). Review: J. Simonsen, W. C. J. Ross, The Terpenes vol. 5 (University Press, Cambridge, 1957) pp 68-74.
Properties
Long prisms from methanol, mp 228-232° with preliminary sintering. [α]D +107° (c = 0.75 in CHCl3). 100 ml of boiling methanol will dissolve 8 grams of β-boswellic acid. Sol in chloroform, ether, acetone, alc.Derivative
Acetate.C32H50O4; mol wt 498.74.
C 77.06%, H 10.10%, O 12.83%.
Properties
Prisms, mp 275-278°, [α]D +63° (c = 1.88 in CHCl3).Derivative
Methyl ester.C31H50O3; mol wt 470.73.
C 79.10%, H 10.71%, O 10.20%.