Wakeman—Pigments of Flowering Plants. 843 
studied by a number of chemists, Moldenhauer, 2 Schuetzen- 
berger 3 and Paraf, Halsiwetz 4 and Pfaundler, Roechleder, 5 
Adrian 6 and Trillot, Herzig, 7 Perkin, 8 and Kostanecki. 9 
Our present conception of the constitution of luteoline, 
like that of the other members of the flavone group, is based 
upon its decomposition by alkaline fusion when it yields phoro- 
glucine and protocatechuic acid. Perkin, therefore ascribed to 
luteoline the foregoing formula which has since been verified 
by the synthesis, effected by Kostanecki 10 and his associates, 
of luteolin from phloracetophenone trimethyl ether and the 
diethyl ether of dihydroxy—3, 4—benzoic acid. 
Luteoline occurs, as such, in Reseda 11 luteola in the leaves of 
Digitalis 12 purpurea , and in Genista 13 tinctoria. The 3-methyl 
ether of luteoline occurs as a glucoside in the leaves of parsley, 
Petroselium sativum. 
Luteoline forms small quadrangular needles of a yellow color 
and bitter, astringent taste. They melt at 350° and sublime 
with partial decomposition. They are slightly soluble in cold 
water, better in warm water, alcohol, ether, and warm acetic 
acid. 
Dry luteoline treated with phosphoric acid anhydride is 
changed to a red substance which dissolves in ammonia with 
a violet coloration. The aqueous solution of luteoline is colored 
first green, then reddish brown by ferric chloride, olive green 
by copper acetate. Luteoline dissolves in concentrated sul¬ 
phuric acid with an orange red color and is precipitated un¬ 
changed by dilution. If to a saturated solution of luteolin in 
boiling acetic acid sulphuric acid is added, small orange red 
crystals, insoluble in acetic acid and decomposed by water into 
luteoline and sulphuric acid, are formed. Hydrobromides are 
formed in a similar manner with hydrobromide acid. 
3 Jr. Prakt. Chem., 70, p. 428. 
3 Bull. Soc. Chim., (1) p. 1861-18. 
4 Ann., 112, p. 107. 
5 Zeit. Anal. Chem. (1886) p. 602. 
6 C. r., 129, p. 889. 
7 Ber., 29, 1013; Monats., 17, p. 926. 
8 Jr. Chem. Soc., 69, p. 206, p. 1439. 
8 Ber., 32, p. 1184; 3j4, 1453; 37, 2625. 
10 Ber., 33, p. 3415. 
11 Ann., 100, p. 150‘; Jares., (1861) p. 707. 
13 Arch. Pharm., 383, p. 313; B., 32, p. 1184. 
13 Euler (1), p. 105. 
