Planta Med 2006; 72 - P_005
DOI: 10.1055/s-2006-949805

Isolation and Structure Elucidation of Anthraquinones from Barleria eranthemoides (Acanthaceae)

L Pieters 1, S Maregesi 1, S Apers 1, A Vlietinck 1
  • 1Laboratory of Pharmacognosy and Phytochemistry, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium

Barleria eranthemoides R. Br. (Acanthaceae) is used in traditional medicine in the Bunda district, Tanzania. Root decoctions or infusions of pounded leaves are drunk for treatment of dysentery and against infectious diseases. Whereas phytochemical and biological investigations on the 80% methanolic extract of roots of B. eranthemoides are still in progress, a series of anthraquinone derivatives have been obtained from the n-hexane extract, which was investigated for its antiprotozoal activity. In addition to barleriaquinone (1), reported before from Barleria buxifolia, and the other known anthraquinones chrysophanol (2), isochrysophanol (3), digitopurpone (4), and 2-methoxy-7-methylanthraquinone (5), a new unusual anthraquinone derivative containing an epoxide moiety (6) was obtained. Structures were elucidated by means of 1D (1H, 13C, DEPT) and 2D (COSY, HSQC and HMBC) NMR and mass spectroscopy.

R1

R2

R3

R4

R5

R6

6

1

OH

H

H

H

Me

H

2

OH

H

Me

H

H

OH

3

OH

Me

H

H

H

OH

4

OH

Me

H

OH

H

OH

5

H

OMe

H

H

Me

H