20.500.12556/DKUM-90316 How deprotonation of cohumulone and colupulone influence their UV/Vis and CD spectrum Cohumulone and colupulone are representatives of - and -acids, respectively. These compounds are important antimicrobial hop (Humulus lupulus) constituents, where cohumulone is an important source of the bitter taste of beer. In this study, we examined the pH dependence of UV/Vis spectra of both compounds while CD spectra of cohumulone were also measured at various wavelengths. This facilitated the examination of the protolytic equilibrium of both compounds, where the second p value of cohumulone was determined for the first time. Additionally, comparing experimental spectra with spectra calculated using time-dependent density functional theory (TD-DFT) enabled the determination of the most likely deprotonation positions and corresponding species most likely present in the aqueous solution at various pH values. Last but not least, comparing calculated and experimental CD spectra of cohumulone facilitated the determination of the absolute stereoconfiguration of cohumulone. cohumulone colupulone UV/Vis spectrum CD-spektrum absolute configuration elagitanini spektroskopija true false true Elsevier Angleški jezik Slovenski jezik https://www.sciencedirect.com/journal/spectrochimica-acta-part-a-molecular-and-biomolecular-spectroscopy © 2024 The Author(s). Članek v reviji 2024-08-29 08:26:53 2024-08-29 08:26:54 2025-06-27 03:14:25 0000-00-00 00:00:00 2024 0 0 11 str. [article no.] 124593 Vol. 320 5 Nov. 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 2024-03-29 2024-06-02 2024-11-05 54 199023619 10.1016/j.saa.2024.124593 1873-3557 1-s2.0-S1386142524007595-main.pdf 1-s2.0-S1386142524007595-main.pdf 1 B669533B17D7C6958A3B905F1E928C4A 4a790676fa1ca54e33ed048ce13f5fde26b3f7b7155213876dbdf7723fa1b045 73370580-525b-11f0-a710-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=192750 https://www.sciencedirect.com/science/article/pii/S1386142524007595?via%3Dihub 0 79fc2dfa-525b-11f0-a710-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=192751 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0