Accessibility navigation


In vivo transformations of dihydro-epi-deoxyarteannuin B in Artemisia annua plants

Brown, G.D. and Sy, L.K. (2007) In vivo transformations of dihydro-epi-deoxyarteannuin B in Artemisia annua plants. Tetrahedron, 63 (38). pp. 9536-9547. ISSN 0040-4020

Full text not archived in this repository.

It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.

To link to this item DOI: 10.1016/j.tet.2007.06.016

Abstract/Summary

[15-(CH3)-C-13-H-2]-dihydro-epi-deoxyarteannuin B (4a) has been fed to intact Artemisia annua plants via the root and three labeled metabolites (17a-19a) have been identified by 1D- and 2D-NMR spectroscopies. The in vivo transformations of 4a in A. annua are proposed to involve enzymatically-mediated processes in addition to possible spontaneous autoxidation. In the hypothetical spontaneous autoxidation pathway, the tri-substituted double bond in 4a appears to have undergone 'ene-type' reaction with oxygen to form an allylic hydroperoxide, which subsequently rearranges to the allylic hydroxyl group in the metabolite 3 alpha-hydroxy-dihydro-epi-deoxyarteannuin B (17a). In the enzymatically-mediated pathways, compound 17a has then been converted to its acetyl derivative, 3 alpha-acetoxy-dihydro-epi-deoxyarteannuin B (18a), while oxidation of 4a at the 'unactivated' 9-position has yielded 9 beta-hydroxy-dihydro-epi-deoxyarteannuin B (19a). Although all of the natural products artemisinin ( 1), arteannuin K ( 7), arteannuin L ( 8), and arteannuin M ( 9) have been suggested previously as hypothetical metabolites from dihydro-epi-deoxyarteannuin B in A. annua, none were isolated in labeled form in this study. It is argued that the nature of the transformations undergone by compound 4a are more consistent with a degradative metabolism, designed to eliminate this compound from the plant, rather than with a role as a late precursor in the biosynthesis of artemisinin or other natural products from A. annua. (C) 2007 Elsevier Ltd. All rights reserved.

Item Type:Article
Refereed:Yes
Divisions:Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
ID Code:11064
Uncontrolled Keywords:terpenes and terpenoids, biogenesis, autoxidation, NMR, DIHYDROARTEMISINIC ACID, ARTEANNUIN-B, QINGHAOSU ARTEMISININ, MICROBIAL-METABOLISM, BIOSYNTHESIS, IDENTIFICATION, MECHANISM, BEHAVIOR, IRON(II)

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation