150 



LECTURE VIII. 



The latter is the next higher homologue, a-amino-glutaric acid: 



COOH 



*CH(NH 2 ) 

 CH 2 

 CH 2 

 COOH. 



Although the amino acids previously mentioned which possess both car- 

 boxyl and amino groups are not distinct acids nor bases, but possess their 

 combined characteristics, these dicarboxylic acids have a distinctively acid 

 character. The natural aspartic acid is the Isevo-rotary. Glutamic acid 

 rotates polarized light to the right. Both dicarboxylic acids occur widely 

 distributed in the vegetable kingdom as amides. Thus asparagine is an 

 amide of amino-succinic acid: 



CONH 2 

 *CHNH 2 

 CH 2 



COOH 



Asparagine. 



It was first found in asparagus sprouts. Soon afterwards it was found 

 that the asparagine collects in the embryo, which are kept in the dark. 

 Asparagine seems to play an important part during germination. E. 

 Schulze, 1 whom we have to thank for very exhaustive investigations 

 on the accumulation of asparagine in embryo, gives the following values : 



As regards the distribution of asparagine in various portions of the 

 embryo, it is worthy of note that Schulze found 31 .81 per cent of aspara- 

 gine in the dry substance of the axillary organs of lupines, while the 

 cotyedons gave only 7. 62 percent. Asparagine occurs in plants in the 

 dextro- and laevo-rotating varieties. The latter occurs more abundantly. 



1 E. Schulze: Landwirtsch. Jahrb. 1878, 411. 



