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Chemistry. — '^On the presence of la peal in some kinds of gutta- 

 percha." By Prof. P. VAN Romburgh. 



An investigation of tlie so-called resinous constituents of various 

 authentic kinds of gutta-percha, made first in conjunction with 

 Dr. Sack and afterwards with Dr. v. d. Linden, has shown that some of 

 them contain various cinnamic esters of alcohols which seem related 

 to cholesterol. One of these cinnamic esters, which appeared identical 

 with Tschirch's^) crystal-albane, and occurs as a beautifully crystallised 

 compound m.p. 241° (corr.) I have submitted to a closer investigation, 

 with Dr. V. d. Linden. On saponification, an alcohol was obtained 

 melting at 210^, which on being treated with benzoyl chloride and 

 pyridine yielded a benzoate melting at 264° (corr.). The melting 

 points of these two last substances agree exactly with those of lupeol 

 and its benzoate. 



Lupeol has been discovered by E. Schulze^) in the skins of lupines. 

 At my request Prof. Schulze was kind enough to present me with 

 a quantity of lupeol and its benzoate for the purpose of compa- 

 rison, for which I wish here to express my best thanks. The alcohol 

 being mixed with the lupeol, the melting point was not lowered; 

 neither was this the case Avith the benzoates. 



In addition to its occurrence as a cinnamic ester, lupeol also 

 seems to occur as an acetate in a substance related to gutta-percha, 

 called "djelutung", the product of the milky juice from some species 

 of Dijera, which is known in European commerce under the 

 name of "bresk" or Pontianak; this has been shown to be probable by 

 Mr. Cohen, who is making a study of this article in my laboratory. 

 In a consignment of "bresk" for which I have to thank Messrs. 

 Weise & Co., of Rotterdam, the amount of lupeol appeared to be 

 rather considerable, thus enabling Mr. Cohen to make a study of this 

 otherwise somewhat inaccessible product. On oxidation with chromic 

 acid a beautifully crystallised ketone (m. p. 169°) has already been 

 obtained, which also yields with hydroxylamine a crystalline substance. 



Mr. Cohen, who intends to further investigate these substances, 

 has also found in the "djelutung" the substance melting at 235°, 

 which I had found previously in the gutta-percha from Payena 

 Leerii, and which has been characterised as the acetic ester of an 

 alcohol melting at 195°. 



1) Arch. d. Pharm. 241, 653. 



2) Zeitschr. f. physiol. Chemie 15, 415 ; 41, 474. 



