— 164 — 



of an oil with a terpene-like odour; 5,15 kilos pelargonium branches (a * 

 hybrid of Pelargonium Radula, 1'Herit. and P. graveolens, 1'Herit.) when 

 distilled yielded 3 cc. oil; 5 kilos leaves of Dryobanalops aromatica, Gaertn. 

 yielded 54 cc. oil. 



On p. 41 of the present Report we refer to Brooks's discovery of the 

 occurrence of an oxidase in the flowers of Michelia Champaca. Brooks l ) 

 has discovered the presence of enzymes with an oxidative action not only 

 in the above-named flowers, but in many other plants yielding volatile oils 

 and it would appear as if these bodies were of considerable importance 

 in the formation of certain constituents of essential oils. For example, 

 Lecomte 2 ) surmises that in the vanilla-plant coniferyl alcohol is converted 

 by an oxidase into vanillin. The fact that the menthone in the pepper- 

 mint herb and the carvone in the caraway plant are principally formed 

 only during the flowering-season, points to the probability that the generation 

 of these oxygenated bodies is connected with the presence of an oxidative 

 enzyme. As a matter of fact, Brooks has succeeded in tracing the oc- 

 currence of oxidase in the peppermint herb and in several other plants. 



In order to establish this fact, the fresh plants were ground with clean 

 quartz sand and a little water to the consistency of a paste, from which 

 he pressed a juice. This he tested with several reagents (guaiac resin, 

 pyrogallol, phenolphthalein) for the presence of enzymes with an oxidative 

 action, and thus he succeeded in demonstrating the occurrence of an oxi- 

 dase in the pressed juice of green caraway fruit. In the peppermint herb 

 the enzymes with oxidative action occur chiefly in the inflorescence; the 

 oxidase-reactions being very feeble with non-flowering plants. In addition 

 to Mentha piperita, the author obtained active extracts from Mentha viridis, 

 M. crispa, M. sylvestris and M. gentilis. The peppermint herb contains a 

 catalase as well as an oxidase. 25 g. Peppermint flowers yielded 25 cc. 

 extract, of which 5 cc. liberated 42 cc. oxygen from 10 cc. 3% hydrogen 

 peroxide solution within the space of 6 minutes. Valerian root contains 

 an enzyme (lipase) which splits up fatty bodies. Brooks has also estab- 

 lished oxidase in tansy leaves, in the leaves of Thuja occidentalis, and in 

 the herb of Satureja montana and of Calamintha officinalis. 



With roses and with palmarosa grass the test for oxidases resulted 

 negatively, and this explains why the oils of these plants contain large 

 proportions of alcohols and but little aldehydes. 



The fact that the scent of many flowers deteriorates shortly aftap* 

 the gathering gives rise to the surmise that the flowers contain oxidases. 

 Brooks is of opinion that flowers of this kind are not well suited for 

 enfleurage. 



x ) Journ. Americ. chem. Soc. 34 (1912), 67. 



2 ) Compt. rend. 133 (1901), 745; Journ. de Pharm. et Chim. 17 (1903)/ 341 ; Comp. Report 

 October 1903, 104. 



