88 ALBERT C. CRAWFORD 



Properties of Adrenalin 



Natural adrenalin melts with decomposition at 211-212 C (uncorr.) ; 

 the synthetic variety melts at 208; the bitartrate of the synthetic base, 

 melts at 149 C. Water at 20 C dissolves 0.0268 per cent. 



It is almost insoluble in the usual organic solvents, but dis- 

 solves in warm ethyl oxalate and also in benzaldehyd (Abel(e) ; Barger 

 and Ewnis). On long standing the base gives off volatile compounds 

 (Abel(/) ). According to Gunn and Harrison (&), adrenalin when treated 

 with an excess of NaOH gives off an odor like that of PH 3 . Warmed 

 with chloral and caustic potash it produces an isonitrile odor. The salts 

 are usually amorphous and deliquescent. A borate is claimed to be stable 

 and not precipitable by NH 4 OH (Imray(fr)). Pauly has prepared a 

 crystalline urate, but the most used crystalline salts are the bitartrate and 

 the oxalate. A crystalline hydrochlorid may be obtained -by dissolving 

 the calculated amount of the synthetic base with the proper amount of 

 alcoholic HC1 and setting the solution aside with frequent agitation. This 

 salt melts at 157 C (B. P. 1907). 



Natural adrenalin is optically active and turns the plane of polariza- 

 tion to the left. Bertrand(a) 53.40, Taveau, quoted by Schultz, 1909, 

 -51.40, Flacher, --51.30, Abel and Macht. 



Like pyrocatechol, adrenalin solutions show an ultra violet absorption 

 spectrum ( Dhere ) . 



Adrenalin reduces Fehling's solution. Its solutions readily oxidize, 

 especially if minute quantities of ferric salts are present (Gunn and Har- 

 rison^)). Oxidation is favored by the glass containers. It especially oc- 

 curs in alkaline solution so that commercial solutions are usually made 

 slightly acid, i. e., acid solutions of the hydrochlorid. A stable solution 

 can also be made by the use of aldehyd or a keto-alkali bisulphite 

 (Straub(a) ). This coloration is associated with a loss in physiological ac- 

 tivity (Liven, Schultz (c) ). Apparently, the Roentgen rays do not change 

 the activity of adrenalin solution (Ludin). Commercial adrenalin gives a 

 reaction with diazohenzensulphonic acid (Pauly's Reagent). The closely 

 related compounds, epinin, tyramin, etc., also give this reaction. 



Aqueous solutions of adrenalin chloric! can be sterilized by heat 

 (Rowc). Some commercial solutions contain sulphites (Puckner), but 

 solutions of adrenalin chlorid were usually preserved with chloretone. 

 Commercial solutions vary greatly in their activity (Sollman and Brown). 



The ease with which oxidation occurs is partly due to the pyrocatechol 

 nucleus and the color reactions used for its identification are usually due 

 to oxidation. Like other pyrocatechol derivatives, adrenalin reacts with 

 ferric chlorid in neutral or slightly acid solutions, by the production 

 of a green color, which changes to violet and red (Weinland and 



