THE CHAULMOOGRA TEEE AND BELATED SPECIES. 7 



CHEMISTRY OF CHAULMOOGRA, HYDNOCARPUS, AND GYNO- 



CARDIA OILS. 



By Frederick B. Power, Chemist in Charge of the Phytochemical Laboratory 

 of the Bureau of Chemistry. 



The attention which has recently been drawn to the successful 

 treatment of leprosy by the use of certain acids contained in chaul- 

 moogra oil, or esters prepared therefrom, renders it desirable that 

 some account should be given of the original researches which 

 led to their discovery and thus made them available as therapeutic 

 agents. The investigations to be considered here, unless otherwise 

 specified, were conducted several years ago in the Wellcome Chemical 

 Research Laboratories, London, and comprised not only an exami- 

 nation of the true chaulmoogra oil but also some related products. 

 Prior to these investigations nothing of a definite nature was known 

 concerning the chemical constituents of these oils, and the statements 

 in the literature concerning them were very superficial and inac- 

 curate. 



I.— CHAULMOOGRA OIL. 



An authoritative definition of chaulmoogra oil is that given by 

 the British Pharmacopoeia, 1914 (9, p. 262), which states it to be 

 " the fatty oil expressed from the seeds of TaraMogenos kurzii 

 King." The acceptance of this definition is important, especially on 

 account of a prevailing tendency to designate the oils from some 

 closely related botanical sources as chaulmoogra oil. It has been 

 shown, however, that the oils from certain species of Hydnocarpus 

 are very similar to the true chaulmoogra oil in their physical char- 

 acters and chemical composition, and they are known to be used for 

 the same purposes in the countries of their production. There would 

 therefore seem to be no reason for excluding such oils from medicinal 

 use when their botanical source is designated. 



It is not necessary in this place to enter into all the details of the 

 respective investigations, especially as a complete account of them 

 may be found in easily accessible chemical literature (1, 18, 19, 21). 

 It may be stated, however, that in all cases the oils examined by the 

 present writer and his collaborators were expressed under the most 

 careful supervision from seeds which had been freshly collected and 

 botanically identified. There was thus complete assurance of their 

 authenticity and purity. 



Chaulmoogra oil is either a brownish yellow liquid or a soft solid 

 which melts at about 22° to 30° C. It possesses a characteristic odor 

 and somewhat acrid taste. The oil consists to a large, extent of the 

 glyceryl esters of optically active acids of a type which had not previ- 

 ously been found to occur in any fatty oil. These acids arc repre 

 sented by the genera] formula (',,11..,, ,')., and have a cyclic structure. 



