2r u2212 cis 1 amino 2 indano is an unequivocal chiral reagent for resolving racemic hop acids it reacts with u00b1 tetrahydrocohumulones to selectively produce a crystal form of tetrahydrocohumulone thco 1s 2r u2212 cis 1 amino 2 indano from the solution of u2212 thco and 1s 2r u2212 cis 1 amino 2 indano it is a dynamic process that can easily process several grams of u00b1 tetrahydro u03b1 acids for any application the thco is a novel bittering precursor as well as its derivatives of u2212 cis trans tetrahydroisocohumulone thico on the other hand its counterpart u2212 thco is identical to the hydrogenated u2212 cohumulone a nature u03b1 acid three thico molecules can be enantioselectively distinguished by our receptors leading to different odor intensities and odor qualities thico ii from its thco have the most bitterness and longest lingering and u00b1 thico iii have milder and smooth bitterness than thico i from u2212 thico the foam situation is more complicated by findings of enantioselective effects of each chiral isomer with damaged conformation of ltp a foam protein during the kettle boiling three thico i ii and iii molecules demonstrate the same antibacterial effectiveness using the minimum inhibitory concentration mic and the bacterial zone of inhibition bzi tests on pediococcus damnosus and lactobacillus brevis it clearly indicates that the enantioselectively antibacterial interactions between thico i ii iii and the microbial do not occur the molecular perception of stereochemistry of tetrahydroiso u03b1 acids prepared from either u03b1 acids or u03b2 acids is very important because of their potential flavor foam antimicrobial contributions in beer verzele and de keukeleire d de keukeleire and m verzele j inst brewing 76 265 1970 u201c chemistry and analysis of hop and beer bitter acids u201d m verzele and d de.