Chromatographic separation and in vitro activity of sorgoleone congeners from the roots of sorghum bicolor.
Sorgoleone, 2-hydroxy-5-methoxy-3-[(8'Z,11'Z)-8',11',14'-pentadecatriene]-p-benzoquinone (1), and its corresponding hydroquinone are the major components of the root exudate of Sorghum bicolor. The name sorgoleone includes minor analogues differing in the length or degree of unsaturation of the 3-alkyl side chain. These compounds are known to be phytotoxic, probably through inhibition of photosystem II (PSII) driven oxygen evolution, as previously demonstrated for 1. Isolation of these sorgoleone congeners was achieved by C(8) column chromatography and argentation thin-layer chromatography, and the purified compounds were structurally characterized. The abilities of the minor sorgoleones to inhibit PSII were similar to that of the major compound, suggesting that all of these sorgoleone congeners contribute to the overall allelopathy of sorghum.
Kagan
Isabelle A
IA
Natural Products Utilization Research Unit, Agricultural Research Service, US Department of Agriculture, University, Mississippi 38677, USA. ikagan@olemiss.edu
Rimando
Agnes M
AM
Dayan
Franck E
FE
D016227:Benzoquinones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D008055:Lipids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D045332:Photosystem II Protein Complex / Q000187:drug effects; D018517:Plant Roots / Q000737:chemistry*; D045868:Sorghum / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D016227:Benzoquinones; D008055:Lipids; D045332:Photosystem II Protein Complex; C113738:sorgoleone