Welcome to Acta Prataculturae Sinica ! Today is Share:

Acta Prataculturae Sinica ›› 2014, Vol. 23 ›› Issue (5): 184-192.DOI: 10.11686/cyxb20140521

• Orginal Article • Previous Articles     Next Articles

Isolation and identification of the potential allelochemicals in the aqueous extract of yellow sweet clover (Melilotus officinalis)

WU Cai-xia,LIU Su-jiao,ZHAO Guo-qi   

  1. College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
  • Received:2014-04-15 Online:2014-10-20 Published:2014-10-20

Abstract:

This study aimed to isolate and identify the main allelochemicals of aqueous extract of yellow sweet clover (Melilotus officinalis). Chromatographic separation, TLC analysis and bioassay test were conducted to isolate the potential allelochemicals of the aqueous extract of yellow sweet clover. GC-MS were used to identify the potential allelochemicals of the aqueous extracts of yellow sweet clover. The results showed that the ethyl acetate phase of yellow sweet clover aqueous extracts containing a variety of allelochemicals, in which coumarin had the highest relative content, then followed by 6-(3-Hydroxy-but-1-enyl)-1,5,5-trimethyl-7-oxabicyclo-[4,1,0]heptan-2-ol, chromanone,2,6-Di-tert-butyl-4-methylphenol, 2-Bromo-1,1,3-trimethyl cyclopropane, trimethyl phosphate, and other substances. The ethyl acetate phase was further separated into three fractions, which were the upper layer, middle layer and lower layer. The chemical which had the highest relative content of the upper layer is also coumarin. In the middle layer, 2-Bromo-1,1,3-trimethyl cyclopropane, 6-(3-Hydroxy-but-1-enyl)-1,5,5-trimethy-7-oxabicyclo[4,1,0]heptan-2-ol, 1-Methylcyclopentanol, trimethyl phosphate and 2-Bromo-1,1,3-trimethyl cyclopropane had higher relative contents. In the lower layer, 2-Bromo-1,1,3-trimethyl cyclopropane, 1-Methylcyclopentanol and cyclohexyl-phosphonous dibromide had higher relative contents. The ethyl acetate phase and the fractions separated from it all showed allelopathic effect on the seed germination and seedling growth of Italian ryegrass, in which the ethyl acetate phase treatment showed the strongest inhibition on seed germination and seedling growth of Italian ryegrass, and significantly stronger than all the treatments of the fractions separated from it (P<0.05). The upper layer treatment showed the second strongest inhibition and significantly stronger than the other two layers (P<0.05). While the lower layer treatment showed significant promoting effects on seed germination and seedling growth of Italian ryegrass (P<0.05). These results suggested that many allelochemicals existing in the aqueous extract of yellow sweet clover, in which coumarin had the highest relative content, and the treatments with higher content of coumarin concentration showed stronger inhibition effect on Italian ryegrass, which also suggested that coumarin should be one of the main allelochemicals in the aqueous extract of yellow sweet clover.

CLC Number: