Cymarin

CYMARIN (Cymarinum), C₃₀H₄₄O₉·1½H₂O, a glycoside found in Indian hemp [Apocynum cannabinum L. (see)]. Cymarin has much in common in its physicochemical and pharmacological properties with strophanthin (see Strophanthus). Cymarin forms colorless prisms with a very bitter taste, sparingly soluble in cold water, readily soluble in hot water, diluted alcohol, chloroform, and ethyl acetate. It is sparingly soluble in absolute alcohol and acetone. It melts at a temperature of 204°–205°; containing 1.5 molecules of H₂O, it melts at 185°–187°; [α]_D = +23.5° (in an 8% chloroform solution). It gives the Kiliani reaction (for digitoxin) and reduces an ammoniacal silver oxide solution upon heating. Sulfuric acid carbonizes cymarin. When heated with acids in an alcoholic solution, cymarin decomposes into cymarigenin and the saccharide cymarose. According to Windaus, cymarigenin is identical with strophanthidin. In its action on animals, cymarin is analogous to strophanthin, differing from the latter by a somewhat more pronounced diuretic effect. Cymarin is used for circulatory insufficiency, particularly in heart defects and myocardial lesions, as well as for insufficient diuresis, edema, dropsy, and so on. Cymarin decreases pulse rate, regulates cardiac rhythm, and enhances diuresis. It is administered internally at 0.3–0.5 mg 2–3 times a day after meals, or intravenously at 0.5–1 mg. Subcutaneous injection of cymarin is painful. In toxicological and forensic-chemical terms, cymarin is analogous to digitoxin and especially to strophanthin (see Strophanthus).