386 ENZYMES 



AmyL Alcohol has been identified in the essential oils of 

 geranium, eucalyptus, lavender, peppermint and chamomile. 



Several unsaturated alcohols, such as citronellol C^qHo^O, 

 geraniol and linalool, both of the formula CigH^gO, occur in 

 essential oils, such as rose oil and oil of bergamot, while 

 amongst the alcohols belonging to the aromatic series must be 

 mentioned cinnamic alcohol, benzyl alcohol, menthol, borneol, 

 etc. Other monohydric alcohols, with the exception of phy- 

 tosterol (see p. 17), are of comparatively rare occurrence. 



Examples of polyhydric alcohols occurring in plants are 

 mannitol, sorbitol, and dulcitol, isomeric substances of the 

 formula — 



CHjOH CHOH CHOH CHOH CHOH CHjOH 



Mannitol occurs to the extent of about 40-50 per cent in 

 manna, the dried sap of Fraxinus Ornus, and also in celery, 

 Syriaga vulgaris, etc. etc. Sorbitol occurs in the berries of the 

 mountain ash, Pyrus Aucuparia. Dulcitol occurs in the cor- 

 tex of Euonymus europaea and in the bark of Euonynius atro- 

 purpurea. 



Adonite* C^Hi^O^ or 



CH3OH CHOH CHOH CHOH CH.pH, 

 is a pentahydric alcohol occurring in Adonis vernalis. Ac- 

 cording to Treboux, f it is converted by the plant into starch, 

 Adonite has a sweet taste, and is used in bacteriological media. 

 Of recent years a number of dihydric alcohols of high mole- 

 cular weight have been found to occur in plants. They belong 

 to different series whose general formulae are — 



CnH2n-604, CnHju-gO^, and CnH2n-io04. 



Trifoliaiiol, C2^H3402(OH)2, isolated by Power and Sal- 

 way,! froni red clover leaves, may be taken as an example 

 of the first group, while Bryonol, CgaHg^O./OH)^, obtained 

 by Power and Moore § from Bryony root, and Calabarol, 

 C23H3^02(OH)2, isolated by Salway || from Calabar beans, are 

 representatives of the second and third groups respectively, 



* Merk: "Chem. Zentr.," 1893, 344. 



+ Treboux: " Ber. deut. bot. Gesells.," igog, 27, 428. 



X Power and Salway : " J. Chem. See, Lond.," igio, 97, 249. 



§ Power and Moore : " J. Chem. Soc, Lond.," 1911, 99, 943. 



II Salway : "J. Chem. Soc, Lond.," 1911, 99, 2155, 



