2493. Columbin
Nomenclature
CAS number: 546-97-4
9-(3-Furanyl)decahydro-4-hydroxy-4a,10a-dimethyl-1,4-etheno-3H,7H-benzo[1,2-c:3,4-c′]dipyran-3,7-dione; 15,16-epoxy-1β,4,12-trihydroxy-5,9-dimethyl-17,18-dinor-8βH,9βH,10α-labda-2,13(16),14-triene-19,20-dioic acid
19,1:20,12-dilactone. C20H22O6; mol wt 358.39.
C 67.03%, H 6.19%, O 26.79%.
Description and references
Major bitter principle from the root of Jatrorrhiza palmata (DC.) Miers (J. columba Miers), Menispermaceae. Isoln: Wittstock, Poggendorff's Ann. 19, 298 (1830). Structure: Barton, Elad, J. Chem. Soc. 1956, 2090. Stereochemistry: Cava et al., Tetrahedron Lett. 1959, 1; Overton et al., J. Chem. Soc. C 1966, 1482; Cheung et al., J. Chem. Soc. B 1966, 853.
Properties
Very bitter needles from methanol, mp 195°. [α]D +52.5° (pyridine). uv max (ethanol): 209 nm (log ε 3.78). Practically insol in water. One gram dissolves in 30 ml acetone, 50 ml ethyl acetate, 75 ml methanol; sol also in chloroform, methylene chloride. Bitterness threshold 1:60,000. Easily isomerized to isocolumbin.Derivative
Isocolumbin.C20H22O6; mol wt 358.39.
C 67.03%, H 6.19%, O 26.79%.