Nomenclature
CAS number: 4670-05-7
1,8-Bis[(2
R,3
R)-3,4-dihydro-3,5,7-trihydroxy-2
H-1-benzopyran-2-yl]-3,4,6-trihydroxy-5
H-benzocyclohepten-5-one.
C
29H
24O
12; mol wt 564.49.
C 61.70%, H 4.29%, O 34.01%.
Description and references
From black tea extracts: Roberts, Myers, J. Sci. Food Agric. 10, 176 (1959).
Structure: Takino et al., Tetrahedron
Lett. 1965, 4019. Configuration: Brown et al., ibid. 1966, 1193.
Properties
Crystals from water, dec 237-240°. Absorption max (ethanol): 216, 271, 384, 470 nm (ε 35500, 19500, 8700, 3600).Derivative
Nonaacetate.
C
47H
42O
21; mol wt 942.82.
C 59.87%, H 4.49%, O 35.64%.
Properties
Crystals, mp 167-168°. uv max (alc): 211, 250, 314, 353 nm (ε 25100, 13200, 7100, 4700).