Senna Leaves(CHAPTER I. The Anthraquinone Group.)

The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
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Bombay, Calcutta, and Madras
1918

Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.

Senna consists of the leaves of various species of cassia which are employed in medicine on account of their purgative properties. It has been the subject of numerous investigations and was long reputed to contain chrysophanic acid.

According to Tschirch and Hiepe (Arch. Pharm., 1900, 238, 427), these leaves contain gluco-sennin, a yellow crystalline substance, probably a glucoside of emodin, senna-emodin, C₁₅H₁₀O₅, melting-point 223-224°, senna-iso-emodin, C₁₅H₁₀O₅, and senna-chrysophanic acid, C₁₅H₁₀O₄, which melts at 223-224°. Senna-rhamnetin, yellow needles, which does not melt below 260°, and a substance C₁₄H₁₀O₅ are also present. Tutin (Chem. Soc. Trans., 1913, 103, 2006), who examined Tinnevelly, Lima and Peru senna leaves, C. angustifolia (Vahl), and the Alexandrian senna leaves, C. acutifolia (Delile), could not confirm the statements of Tschirch and Hiepe as to the presence of senna-iso-emodin or senna- chrysophanic acid.

The anthraquinone derivatives isolated consisted solely of aloe-emodin, C₁₅H₁₀O₅, and rhein, C₁₅H₈O₆, and these were present partly in the free condition and partly as glucosides. Senna leaves also contain kaempferol, C₁₅H₁₀O₆ (see Delphinium consolida), and a new glucoside of this substance, kaempferin,C₂₇H₃₀O₁₆6H₂O, melting-point 185-195°. In addition to the above-mentioned compounds, the senna leaves from Lima and Peru contained isorhamnetin, C₁₆H₁₂O₇, identical with that first isolated by Perkin from the yellow wallflower (Chem. Soc. Trans., 1896, 69, 1658), and this is probably the so-called sennarhamnetin of Tschirch and Hiepe.