814 Wisconsin Academy of Sciences , Arts, and Letters. 
mango leaves. Enxanthone was first studied by Stenhouse 1 in 
1844 and a little later by Erdman 2 who named both the free 
euxanthone and the acid compound. In 1889 Graebe 3 synthe¬ 
sized euxanthone and made a study of its structure. The com¬ 
plete structure of the molecule was determined by Kostanecki 4 
and Nessler, 1891-1894. As yet euxanthone does not appear to 
have been isolated directly from the plant in which it may or 
may not exist. 
Euxanthone forms pale yellow needle like crystals which melt 
at 240°. It forms disodium and dipotassium 5 compounds 
which are red in color. Its monomethyl ether 6 is pale yellow 
in color and its dimethyl ether is colorless. Other derivatives 
of euxanthone have been studied by Perkin. 7 
II. A. 1. c.) Penthydroxy derivatives of diphenyl methanone. 
Maclurin, — Penthydroxy — 2, 4, 6 , 3', 4'—diphenyl Methanone. 
CH CH 
Maclurin, also called penthydroxy benzophenone and moringa 
tannic acid, occurs in Morns tinctoria n along with morin. Mac¬ 
lurin has been known for a long time and has called forth a 
large number of investigations. It was first isolated by Wag¬ 
ner 2 in 1850. Wagner considered the substance to be a tri- 
basie acid isomeric with morin. Illasiwetz and Pfaundler 3 in 
1863 recognized the fact that maclurin is not an acid. Bene- 
1 Ann., 51, p. 423. 
3 Jr. Prakt Chem., 33, p. 190. 
3 Ann., 54, p. 265. 
4 Ber., 24, p. 3980; 27, p. 1989. 
“Ann., 290, p. 156. 
8 Ann., 318, p. 365. 
7 Jr. Chem. Soc., 73, p. 671. 
1 Czapek, II., p. 521. 
3 Jr. Prakt. Chem., 51, p. 82; 52, p. 449. 
3 Ann., 127, p. 354; 134. p. 122. 
