Title: Columbin
CAS Registry Number: 546-97-4
CAS Name: 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
Additional Names: 15,16-epoxy-1b,4,12-trihydroxy-5,9-dimethyl-17,18-dinor-8bH,9bH,10a-labda-2,13(16),14-triene-19,20-dioic acid 19,1:20,12-dilactone
Molecular Formula: C20H22O6
Molecular Weight: 358.39
Percent Composition: C 67.03%, H 6.19%, O 26.79%
Literature 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., ibid. (B) 1966, 853.
Properties: Very bitter needles from methanol, mp 195°. [a]D +52.5° (pyridine). uv max (ethanol): 209 nm (log e 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.
Melting point: mp 195°
Optical Rotation: [a]D +52.5° (pyridine)
Absorption maximum: uv max (ethanol): 209 nm (log e 3.78)
Derivative Type: Isocolumbin
Molecular Formula: C20H22O6
Molecular Weight: 358.39
Percent Composition: C 67.03%, H 6.19%, O 26.79%
Properties: Needles from methanol, dec 190°. [a]D17 +0.17° (alk alc). uv max (alc): 209 nm (log e 3.80).
Optical Rotation: [a]D17 +0.17° (alk alc)
Absorption maximum: uv max (alc): 209 nm (log e 3.80)
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