New Glycosides from Senna

Abstract

Sm,-The letter by Vickers in the August issue of this Journal (1961) has stimulated us to report the isolation of five anthracene glycosides from senna since our report of the separation of an active primary glycoside (Fairbairn, Friedmann and Ryan, 1958).This has been isolated from Alexandrian senna pod and appears to be similar to that reported by Vickers. We have shown it to be a rhein-monoglucoside by chemical analysis. Ultra-violet absorption measurements indicate that the compound is identical with synthetic rhein-8-glucoside, prepared from authentic rhein anthrone-8-glucoside by aerial oxidation in sodium borate solution at pH 9.2, and differs from a sample of synthetic rhein-1-glucoside, kindly supplied by Dr. A. C. Bellaart. Our experience is that the glucoside isolated by us is not readily decomposed by sodium bicarbonate solution with the formation of rhein, which does not accord with the inference that can be drawn from Vickers' letter.Rhein-8-diglucoside. A second glycoside isolated has been shown to be rhein-8-diglucoside. This glycoside, is much more soluble in water than the 1or 8-monoglucosides. It can be converted into the 8-monoglucoside by treatment with 0 . 1~ hydrochloric acid at room temperature.Rhein anthrone-8-glucoside, which is virtually half a sennoside molecule, was also found by us to be present in senna pod. This has been identified by hydrolysis to rhein anthrone, which was characterised spectroscopically, and by the formation of a green compound (Amax 640 mp) with p-nitrosodimethylaniline in pyridine (Tsukida and Suzuki, 1954). The conversion of rhein anthrone-8-

Anthraquinone Derivatives in Vegetable Laxatives

“…Zwaving (27) found only dianthrone glyco sides, accompanied by small quantities of the related anthraquinone glucosides, but no mono-anthrone glycosides in the dried leaves. Other authors (10,26) found comparatively small quantities of anthrone glucosides or aglycones in the leaves; only one of them found a mono-anthrone glucoside also in the pods (3).…”

Oxalated, Sulphated and Primary Glycosides

“…Equivalent weight determination indi cated that it was an even larger molecule than that described above; the compound was deacetylated, but not further purified, and its biological activity shown to be about twice that of sennosides on a molar basis. Later, Crellin et al (1961) reported briefly on a further primary glycoside with a molecular weight of about 2,000. Schmid and Angliker (1965) criticised this work and claimed that these primary glyco sides were mixtures of normal senna glycosides: the fact that they were mixtures imparted extra water solubility and enhanced biological activ ity.…”

The compounds in Aloë leaf exudates: a review

“…Unspecified aloe-emodin glycosides have been reported from Cassia senna L. (Rai et al, 1974), Cassia angustzfolia Vahl. (Crellin, Fairbairn, Friedmann & Ryan, 1961;Zwaving, 1965Zwaving, , 1974 and Rheum palmatum (Horhammer, Wagner & Leue, 1959;Zwaving, 1965Zwaving, , 1974. Chrysophanol-8-P-D-glucoside has been detected in Asphodelus microcarpus Salzm.…”

“…Uncharacterized dianthrone glycosides have been found in Rhamnuspurshiana bark (Kinget, 1968). More complex compounds containing the sennoside molecule with additional sugar units have been described from senna (Crellin et al, 1961;Fairbairn, 1964;Fairbairn, Friedmann & Ryan, 1958).…”