Structure and toxicity of the alkaloids of Russian comfrey (Symphytum x uplandicum Nyman), a medicinal herb and item of human diet

Structure and toxicity of the alkaloids of Russian comfrey (Symphytum x uplandicum Nyman), a medicinal herb and item of human diet The alkaloids of Symphytum × uplandicum (Russian comfrey) Analysis, separation, and bioassay of pyrrolizidine alkaloids from comfrey (<i>symphytum officinale</i>) Symviridine, a new pyrrolizidine alkaloid from Symphytum species Toxicity of Comfrey–Pepsin Preparations Analysis of herbal teas made from the leaves of comfrey (Symphytum officinale): reduction of N-oxides results in order of magnitude increases in the measurable concentration of pyrrolizidine alkaloids Isolation of Symlandine from the Roots of Common Comfrey (<i>Symphytum officinale</i>) Using Countercurrent Chromatography Assessment of the diversity of comfrey (Symphytum officinale L. and S. × uplandicum Nyman) Studies on Constituents of Crude Drugs. I. Alkaloids of Symphytum officinale LINN. Pyrrolizidine Alkaloid Composition of Three Chinese Medicinal Herbs, <i>Eupatorium cannabinum</i>, <i>E. japonicum</i> and <i>Crotalaria assamica</i>