562 The Philippine Journal of Science 1923 



pure acids. (Power gives 58.6° for chaulmoogric acid and 68.1° 

 for hydnocarpic.) Hydnocarpus alcalae and H. subfalcata, 

 however, show notable amounts of stearic or a similar acid (by 

 their low rotation), and all of the oils have some inactive acid 

 which remains in the b fraction. 



The absence of chaulmoogric and hydnocarpic acid in Pangium 

 edule would seem to be definitely shown by this determination. 

 It is possible, however, that these acids are present together 

 with an enzyme which causes their destruction. Sample A of 

 Pangium edule was insufficient for the ester distillation test, so 

 sample B was prepared. After the absence of rotation in the 

 esters of this sample was discovered it was found that the oil it- 

 self had no rotation. The second-grade oil of sample A (Table 

 3) has a very low rotation. Unfortunately we have no more 

 seeds available for further work on this at present, but the 

 evidence so far points to the absence of chaulmoogric and hydno- 

 carpic acids in Pangium edule. 



Saponification number.— It was hoped that this value would 

 enable us to make the determination of the relative amounts of 

 16-carbon-atom and 18-carbon-atom acids in each oil. In gen- 

 eral, the fractions 2 b and 5 b show higher saponification num- 

 bers (lower molecular weights) than the corresponding a 

 fractions, as was expected, while fractions 1 b and 6 b are about 

 the same as 1 a and 6 a, since fractions 1 and 6 are each fairly 

 homogeneous, in respect of molecular weight, being end frac- 

 tions in the distillation. There is evidently, however, some 

 cause of variation in the saponification numbers, the nature of 

 which we cannot definitely state, and which makes them unre- 

 liable as indications of the relative amounts of 16-carbon-atom 

 and 18-carbon-atom acids in a fraction. 



CONCLUSION 



The foregoing data show a close similarity between the oil 

 of Taraktogenos kurzii and all the Hydnocarpus oils that we 

 were able to obtain. The only one of the latter that is distinctly 

 different is Hydnocarpus alcalae, which contains a very large 

 amount of chaulmoogric acid, and little or no hydnocarpic acid. 



The other Hydnocarpus oils, like chaulmoogra oil, may each 

 be separated into fractions (by the distillation of the ethyl 

 esters) containing 16-carbon-atom acids and fractions contain- 

 ing 18-carbon-atom acids. The 16-carbon-atom fractions of 

 each contain hydnocarpic acid and an unknown acid or acids 

 which can be separated only very incompletely from the hydno- 



