Impact of D2O on peptidization of L-histidine

Abstract This is our sixth consecutive study carried out in an order to collect experimental evidence on the impact of heavy water (D 2 O) spontaneous peptidization proteinogenic α -amino acids and this time it L -histidine ( -His). Scientists have not yet achieved a full consensus regarding source very important amino acid human mammalian tissues, particular question rather contradictory answers form results are produced, equally supporting its exogenous endogenous origin. Although issue still remains unsolved, for practical demands life sciences two UN agencies, FAO WHO, both tentatively accepted that -His acid. As analytical techniques, studies we employed high-performance liquid chromatography with diode array detection (HPLC–DAD), mass spectrometry (MS), scanning electron microscopy (SEM). Spontaneous dissolved methanol + H O, 7:3 v / ) was at 22 ± 0.5 °C darkness relatively long period 314 h, progress chromatographically checked by targeting concentration monomer 12-min intervals. investigation revealed alternating non-periodic changes, indicating changeable formation hydrolytic decay -His-derived oligopeptides function time, fast net fall (witnessing quite vigorous peptidization). Moreover, MS confirmed high oligopeptides, falling within range or more dozen units. Impact D O traced use SEM samples aqueous solvents containing 5, 10, 20, 30% also pure O. Similar earlier presented five other acids, exerts powerful inhibitory effect -His, perceptible when assessed aid (with spectra first instance playing role quasi-quantitative fingerprints), based purely qualitative micrographs derived SEM.