— 130 



organism oxidises in the same manner as outside the body. The following 

 formulae have been accepted for camphene : — 



CH CH CH CH 9 CH 



CH q 



CH 3 



CH 



CH, 



CH, 



CH, 



C 



I 

 -C- 



CH 3 

 Bredt 1 ) 



-CH — 



I 



I 

 -C- 



CH 



•CH 9 



-CH 



CHOH 



CH, 



CH 



-CHOH 



CH, 



CH 



CH, 



CH-CHO 



CH Q 



CH 3 

 Camphene glycol ( W a g n e r) 2 ) Camphenilane aldehyde (Bredt) 8 ) 



Wagner has obtained from camphene, by careful oxidation, camphene 

 glycol, and has converted the latter by heating with dilute hydro- 

 chloric acid into an aldehyde, which Bredt considers identical with the 

 camphenilane aldehyde produced by himself. In a similar manner 

 the process in the organism may be imagined, inasmuch as in splitting 

 up camphene glycol - glycuronic acid, this aldehyde is also formed, 

 on the oxidation of which the acid C 10 H 16 O 2 originates: isocamphenilic 

 acid, m. p. 118 04 ). According to this it is not improbable that other 

 terpenes of the "pseudo" class experience an analogous change, from 

 which, in the case of sabinene, the difference in the products of 

 conversion as compared with those of sabinol can be explained. In 

 the compounds belonging to the ortho-class of the terpenes, such as 

 limonene, an oxidation of the methyl-group situated in p-position to- 

 wards the isopropyl-group, into carboxyl, and also a hydroxylation in 

 the nucleus, come under consideration. 



Such an oxidation of a methyl-group situated on the ring has 

 been detected with certainty in an aldehyde, viz., citral 5 ) from lemongrass 

 oil (although this aldehyde belongs to the aliphatic series). Citral 

 also stands in close relation to p-cymene; Semmler 6 ) converted it 

 direct into p-cymene by heating with potassium bisulphate to 190 : 



^CH-CH 



CH Q 



CH, 



\C:CH.CH 2 .CH 2 -C: CH-CHO 



CH 8 



*) Liebig's Annalen 310 (1900), 134. 



CH, 



CH, 



\ 



CH-C 



V-CH S 



^CH=CH 



2 ) Berl. Berichte 23 (1890), 2309. 

 8 ) Liebig's Annalen 310 (iqoo), 116. 



4 ) E. Fromm, H. Hildebrandt, P. Clemens, Zeitschr. f . physiol. Chemie37 

 (1902); Report April 1903, 81. 



5 ) H. Hildebrandt, Arch. f. exp. Pharmakol. 45 and 46 (1901). 



6 ) Berl. Berichte 24 (1891), 201. 



