AMINO ACIDS IN PLANTS 321 



OCCURRENCE OF AMINO "ACIDS IN PLANTS. 



Leucine occurs as such in the buds of the horse-chestnut * 

 and many other plants. Isoleucine has been discovered by 

 Feh'x EhrHch f in the residual molasses obtained from sugar 

 refineries. 



Lysine and histidine have been isolated from sprouting 

 plants by Schulze.t 



Arginine has been observed in the cotyledons of lupin 

 seeds and in etiolated pumpkin seeds, § and also in several 

 species of conifers. 



Phenyl alanine was discovered by Schulze and Barbieri \ 

 in etiolated germinating lupin seeds. 



Tyrosine, according to Shibata,^! occurs in considerable 

 quantity in rapidly growing shoots of Japanese bamboos, and 

 in small quantity in seedlings of Liipinus albus** and Vicia 

 saliva ;W it has also been described as occurring with aspara- 

 gine in the root-tubers of Dahlia variabilis. According to 

 Bertel, \\ tyrosine is converted into homogentisinic acid by an 

 oxidase (see p. 359) contained in the plant, which is a change 

 similar to the one produced in the human body in the condi- 

 tion known as alkaptonuria. §§ Schulze and Castoro, llll how- 

 ever, deny the accuracy of these observations. 



Tryptophane has been found in seedlings of Liipinns albus, 

 Vicia saliva, and in Pisum sativum ^^ 



Proline is obtained by the hydrolysis of a number of proteins 

 of vegetable origin, notably the prolamins, but has not so far 

 been found to occur as such in any plants. 



*Schulze and Barbieri: "J. prakt. Chem.," 1S82, 15, 145; Schulze and 

 Winterstein : "Z. physiol. Chem.," 1902, 35, 299. 



fEhrlich : " Ber. deut. chem. Gesells.," 1904, 37, 1809. 



J Schulze : "Z. physiol. Chem.," 1S99, 28, 465. 



§ Schulze and Steiger : "Z. physiol. Chem.," 1887, 11, 43; "Ber, deut. 

 chem. Gesells.," 1886, 19, 1177. 



II Schulze and Barbieri: "Ber. deut. chem. Gesells.," 1881, 14, 1785. 



IFShibata: "J. Coll. Sci. Tokyo," igoo, 13, 329. 



** Schulze and Castoro: "Z. physiol. Chem.," igo6, 48, 387, 396. 



t+Gorup Besanez : "Ber. deut. chem. Gesells.," 1877, 10, 7S1. 



+:}: Bertel: " Ber. deut. bot. Gesells.," 19 j2, 20, 45}. 



§§Wolkow and Baumann : "Z. physiol. Chem.," 1891, 15, 266. 



II II Schulze and Castoro: loc. cif. 



HI Schulze and Winterstein : "Z. physiol. Chem.," 1910, 65, 431. 



