8176. Rhein
Nomenclature
Description and references
Found in the free state and as glucoside in Rheum spp, Polygonaceae (rhubarb) and in Senna leaves; also in several spp of Cassia (Leguminosae). Diacetate used as antirheumatic. Isoln from Chinese rhubarb: J. Schlossberger, O. Doepping, Ann. 50, 196 (1844); O. Hesse, ibid. 309, 32 (1899); F. Tutin, H. W. B. Clewer, J. Chem. Soc. 99, 946 (1911); from aloe-emodin, q.v.: O. A. Oesterle, Arch. Pharm. 241, 604 (1903); from Cassia alata L.: H. Hauptmann, L. L. Nazario, J. Am. Chem. Soc. 72, 1492 (1950); from C. fistula: V. K. Murty et al., Tetrahedron 23, 515 (1967). Prepn from chrysophanic diacetate: Fischer et al., J. Prakt. Chem. [2] 83, 208; 84, 369 (1911). Structure: H. Nawa et al., J. Org. Chem. 26, 979 (1961). Use in arthritis: C. A. Friedmann, DE 2711493; idem, US 4244968 (1977, 1981 both to Proter). Spectrophotometric study: A. A. Habib, N. A. El-Sebakhy, J. Nat. Prod. 43, 452 (1980). Determn by gas chromatography, mass spectroscopy: G. W. Van Eijk, H. J. Roeijmans, J. Chromatogr. 295, 497 (1984); HPLC: A. J. J. Van den Berg, R. P. Labadie, ibid. 329, 311 (1985). Pharmacological effects on colonic mucosa: R. Wanitschke, Pharmacology 20, Suppl. 1, 21 (1980); K. Ewe, ibid. 27. Metabolism study: J. Lemli, L. Lemmons, ibid. 50. In electron transport: P. Egerer et al., Z. Physiol. Chem. 363, 627 (1982). Inhibition of proteases: L. Raimondi et al., Pharmacol. Res. Commun. 14, 103 (1982). Effect on prostaglandin biosynthesis: S. Franchi-Micheli et al., J. Pharm. Pharmacol. 35, 262 (1983).
