8243. Robinin

Nomenclature

CAS number: 301-19-9
3-[[6-O-(6-Deoxy-α-l-mannopyranosyl)-β-d-galactopyranosyl]oxy]-7-[(6-deoxy-α-l-mannopyranosyl)oxy]-5-hydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one; kaempferol 3-robinoside 7-rhamnoside.
C33H40O19; mol wt 740.66.
C 53.51%, H 5.44%, O 41.04%.

Description and references

Dimorphic flavanoid isolated from the leaves and flowers of Robinia pseudoacacia L., Leguminosae: C. Zwenger, F. Dronke, Ann. suppl. 1, 257 (1861); C. Sando, J. Biol. Chem. 94, 675 (1932). Structure: Zemplén, Bognár, Ber. 74B, 1783 (1941). Total synthesis and structure: L. Farkas et al., Phytochemistry 15, 215 (1976).

Chemical structure

Derivative

β-Form.

Properties

Yellow crystals, mp 250-254° (Farkas); also reported as straw-yellow needles from alc, mp 249-250° (Sando). uv max (ethanol): 352, 368 nm (log ε 4.14, 4.18), Jurd, Horowitz, J. Org. Chem. 22, 1619 (1957). Sol in hot water, hot alc; practically insol in ether. On hydrolysis yields kaempferol, q.v.

Derivative

α-Form.

Properties

Obtained by crystallization from water and dehydrating, mp 195-197° (Sando). Also reported as hydrate, yellow needles from aq methanol, mp 196-199° (Farkas).