Introduction Directory UMM :Data Elmu:jurnal:P:PlantScience:PlantScience_Elsevier:Vol150.Issue1.2000:
Plant Science 150 2000 93 – 101
Xanthone biosynthesis and accumulation in calli and suspended cells of Hypericum androsaemum
A.C.P. Dias
a,
, R.M. Seabra
b
, P.B. Andrade
b
, F. Ferreres
c
, M. Fernandes-Ferreira
a
a
Departamento Biologia, Laboratorio Biologia Vegetal, Uni6ersidade do Minho, Campus de Gualtar,
4710
-
057
Braga Codex, Portugal
b
CEQUPLaboratorio Farmacognosia, Faculdade de Farma´cia, Uni6ersidade do Porto, R. Anibal Cunha,
4050
Porto, Portugal
c
Departamento De Ciencia y Tecnolog
’
a de Alimentos, Laboratorio Fitoquimica, CEBAS CSIC
, P.O. Box
4195
, Murcia
30080
, Spain Received 1 March 1999; received in revised form 10 September 1999; accepted 10 September 1999
Abstract
Calli and suspended cells of Hypericum androsaemum accumulated high levels of 1,3,5,6 and 1,3,6,7 oxygenated xanthones. The major compounds include simple oxygenated xanthones or derivatives with prenyl, pyran or methoxyl groups, four of them being
new natural compounds. A hypothetical biosynthetic scheme is proposed based on the isolated compounds and statistical analysis. Xanthone accumulation was influenced greatly by medium factors, namely hormone supplementation. Calli grown with 4.5 mM
a -naphtaleneacetic acid NAA + 2.3 mM kinetin KIN had the highest specific xanthone production 1.3 biomass dry weight
DW, whereas suspended cells grown in similar medium accumulated a lower amount 0.87 DW. Calli displayed a negative linear relationship between total xanthone accumulation and NAA concentration, in the range of 4.5 – 22.5 mM. However, in this
range the xanthone 1,3,6,71,3,5,6 ratio and the biomass production showed a positive linear relationship with NAA concentra- tion. Substitution of 4.5 mM of NAA by the same molar amount of 2,4-dichlorophenoxyacetic acid 2,4-D, in the presence of 2.3
m M of KIN, caused a decrease in xanthone accumulation in calli. The use of N
6
-benzyladenine BA instead of KIN reduced xanthone production, independently of the auxin used. This effect was attenuated when both hormones were present. © 2000
Elsevier Science Ireland Ltd. All rights reserved.
Keywords
:
Hypericum androsaemum; Calli; Cells suspension; Xanthones; Phytohormones www.elsevier.comlocateplantsci