The H NMR of the humulone we isolated was compared to a H NMR of known humulone in order to verify that we correctly isolated humulone. The process developed by Sharpe and Ormrod can effectively be used to isolate humulone. An original 30.236 g of hop oil yielded 1.333 g of humulone. Even with slight alterations, the humulone can still be extracted in a similar amount of time and to a similar purity.
Humulone obtained from the isolation was diluted with ethanol and a pH 10 buffer to observe the effects that a basic pH has on the isomerization of humulone into isohumulone. The optical rotation of the diluted compound should have been around -1.06° if it was humulone, 0.2335° for cis-isohumulone, -0.039° for trans-isohumulone, or 0.09725° for a 50/50 combination of cis- and trans- isohumulone. The optical rotation for the compound was at a steady value of about 0.197°. This could mean that the addition of ethanol and a pH 10 buffer caused humulone to isomerize into isohumulones, with more cis-isohumulone isomerizing than trans-isohumulone. To better identify the compound, we took an H NMR. The peaks of the unknown compound had distinct differences from the know humulone peaks. Since the compound was not humulone, we thought it might have isomerized into isohumulone.
For a comparison, we isolated isohumulone by loosely following US patent 3,354,219 on a Method for Preparation of Isohumulone Concentrates. We used an H NMR of the resulting isohumulone to compare and possibly identify the compound that resulted from the addition of a 8 mL ethanol and 2 mL pH 10 buffer. The H NMRs of the two compounds had definite differences. Therefore, we were able to confirm that the unknown compound that resulted from the ethanol and buffer addition was not isohumulone. It is possible that an NH4OH salt and humulone complex was the resulting compound, but further analyzation is needed.
Humulone obtained from the isolation was diluted with ethanol and a pH 10 buffer to observe the effects that a basic pH has on the isomerization of humulone into isohumulone. The optical rotation of the diluted compound should have been around -1.06° if it was humulone, 0.2335° for cis-isohumulone, -0.039° for trans-isohumulone, or 0.09725° for a 50/50 combination of cis- and trans- isohumulone. The optical rotation for the compound was at a steady value of about 0.197°. This could mean that the addition of ethanol and a pH 10 buffer caused humulone to isomerize into isohumulones, with more cis-isohumulone isomerizing than trans-isohumulone. To better identify the compound, we took an H NMR. The peaks of the unknown compound had distinct differences from the know humulone peaks. Since the compound was not humulone, we thought it might have isomerized into isohumulone.
For a comparison, we isolated isohumulone by loosely following US patent 3,354,219 on a Method for Preparation of Isohumulone Concentrates. We used an H NMR of the resulting isohumulone to compare and possibly identify the compound that resulted from the addition of a 8 mL ethanol and 2 mL pH 10 buffer. The H NMRs of the two compounds had definite differences. Therefore, we were able to confirm that the unknown compound that resulted from the ethanol and buffer addition was not isohumulone. It is possible that an NH4OH salt and humulone complex was the resulting compound, but further analyzation is needed.