146 THE SIMPLER NATURAL BASES 



Hypaphorine. 



The isolation from the seeds of Erythrina Hypaphorus is carried 

 out, according to GreshofT, by adding dilute nitric acid to an aqueous 

 or alcoholic extract of the powdered cotyledons ; this causes the very 

 sparingly soluble nitrate to crystallise out. The yield is 3 per cent, of 

 the dried seeds. 



The free base is obtained from the nitrate by adding concentrated 

 sodium carbonate solution ; the base then separates as an oily upper 

 layer which soon crystallises. Hypaphorine is also obtainable from 

 an aqueous extract, after purification with lead acetate and concen- 

 tration. The mother liquor of the crystals of the free base is treated 

 with nitric acid and yields a further quantity as nitrate. 



Hypaphorine crystallises from water in large monoclinic trans- 

 parent crystals of the composition C U H 18 O 2 N 2 . 2H 2 O which effloresce 

 in a desiccator. 



The anhydrous substance melts at about 255 with decomposition. 

 It is dextro-rotatory; in 1-3 per cent, solution in water [a]o = +93- 

 Hypaporine dissolves very readily in water and also readily in alcohol, 

 but not in other organic solvents. The aqueous solution is neutral to 

 litmus and, if not very dilute, yields precipitates with most alkaloidal 

 reagents. Gold chloride is reduced and coloured red even by dilute 

 solutions ; potassium permanganate is decolourised and a solution 

 containing ferric chloride and potassium ferricyanide yields Prussian 

 blue. -The solution of the base in concentrated sulphuric acid yields 

 with various oxidising agents (potassium dichromate, ferricyanide, 

 etc.) an intense violet coloration which soon disappears. The close 

 relationship between hypaphorine and tryptophane is shown by the 

 fact that the former substance also gives Hopkins and Cole's reaction 

 with glyoxylic and sulphuric acids, but hypaphorine does not react with 

 triketohydrindenehydrate. In spite of the similarity of its structure to 

 that of tryptophane, hypaphorine yields on oxidation with ferric chloride 

 only traces of yS-indole aldehyde. 



The most characteristic salt is the nitrate, C 14 H 18 O 2 N 2 . HNO 3 , which 

 melts with decomposition at 215-220 and dissolves at room tempera- 

 ture in about 170 parts of water; other crystalline salts and the free 

 base are much more soluble. 



The quaternary iodide, C 16 H 21 O a N 2 I, obtained by methylation from 

 both tryptophane and hypaphorine, forms glistening plates from boiling 

 water and dissolves in 200 parts of water at 18. 



