Mechanistic studies on diamine oxidase: oxidation of α,ω-diamines does not involve an enamine intermediate

Abstract

ROBINS. Can. 72, 31 (1994).Three labelled labe labelled a,o-diarnines were synthesized and incubated with pea seedling diamine oxidase. The aminoaldehydes formed by oxidative deamination cyclized to the corresponding imines, which were trapped with benzoylacetic acid. In all three cases the acetophenone derivatives produced were shown by NMR and mass spectrometry to contain four deuterium atoms. The retention of all four deuterium atoms demonstrates that oxidative deamination of a,o-diamines catalyzed by pea seedling diamine oxidase does not involve an enarnine intermediate as previously suggested. STEPHEN S. GAVIN, ANGELA M. EQUI et DAVID J. ROBINS. Can. 72,31 (1994).On a synthktisk trois ~,~.~' ,~' -~~~-a , o -d i a m i n e s et on les a incubtes avec de la diarnine oxydase de la semence de pois. Les trois arninoaldkhydes qui se forment par dksamination oxydante se cyclisent en irnines correspondantes que l'on peut pitger a l'aide d'acide benzoylacktique. Dans les trois cas, on a dkmontrk, par RMN et par spectromttrie de rnasse, que les dkrivks acetophknones qui se forment contiennent toutes quatre atomes de deutkrium. La rktention des quatre atomes de deutkrium dtrnontre que, contrairement h ce qui avait kt6 suggtrt antkrieurement, la dksamination oxydante des a,odiamines catalyske par la diamine oxydase de la semence de pois n'irnplique pas d'interrntdiaire knamine.[Traduit par la redaction] Introduction Decarboxylation of basic a-amino acids such as ornithine and lysine followed by the oxidative deamination of the resulting diamines, putrescine (1) and cadaverine (2), respectively, are key steps in amino acid metabolism and the biosynthesis of many alkaloids (1). Naturally occurring polyamines such as 1 also have an important function in the control of growth and proliferation processes (2). Putrescine is formed by decarboxylation of L-ornithine catalyzed by L-ornithine decarboxylase. The stereochemistry of this process was studied by several groups of workers (3-7). An analogous process operates on the homologue L-lysine, which leads to cadaverine on decarboxylation with L-lysine decarboxylase. Again this process was shown to proceed with retention of configuration (6-9). The next step in the metabolism of the diamines 1 and 2 is oxidative deamination to the corresponding aldehydes 5 and 6 catalyzed by diamine oxidase (DAO, EC 1.4.3.6) (Scheme 1). The stereochemistry of these processes was studied extensively by 10) and by other groups of workers (9, 11). DAO catalyses the removal of the 1-pro-S hydrogen from 1 and 2.A series of N-alkylputrescines was tested as substrates of DAO by Frydman et al. (12). With the surprising exception of N-methylputrescine, these diamines were shown to be oxidized to the corresponding aminoaldehydes. We repeated this work using an improved kinetic assay procedure, and demonstrated that N-methylputrescine was in fact a good substrate for pea seedling and pig kidney DAO (13). A range of derivatives of 1

The influence of structural features on facile McLafferty‐type, even‐electron rearrangements in tandem mass spectra of carboxylate anions

“…Deuterium exchange was achieved using a modified, published procedure 29. Accordingly, sodium 4‐cyanobutanoate was heated in a mixture of D 2 O/dioxane (7:2) and diazabicyclo[5.4.0]undec‐7‐ene (DBU, 0.5 equiv.)…”

Oxidative Deamination of Tetrahydroanabasine with o-Quinones: An Easy Entry to Lupinine, Sparteine, and Anabasine

“…The lupin alkaloids have been an attractive synthetic target for several decades. During this period an increasing number of lupin alkaloids were identified from several lupin species, and attention was given to their biogenesis. − Numerous labelling experiments have been performed, leading to the conclusion that cadaverine, and thus lysine, is the source of the carbon and nitrogen atoms present in these alkaloids. Schöpf studied the chemistry of dehydropiperidine ( 1 ), the expected product of the oxidative deamination of cadaverine in vivo (Scheme ).…”