Identification of two phytotoxins, blumenol A and grasshopper ketone, in the allelopathic Japanese rice variety Awaakamai

Hisashi Kato-Noguchi, Kazuya Tamura, Hiroaki Sasaki, Kiyotake Suenaga

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Aqueous methanol extracts of the traditional rice (Oryza sativa) variety Awaakamai, which is known to have the greatest allelopathic activity among Japanese traditional rice varieties, inhibited the growth of roots and shoots of cress (Lepidium sativum), lettuce (Lactuca sativa), timothy (Phleum pratense), Digitaria sanguinalis, Lolium multiflorum and Echinochloa crus-galli. Increasing the extract concentration increased the inhibition, suggesting that the extract of Awaakamai contains growth inhibitory substances. The extract of Awaakamai was purified and two main growth inhibitory substances were isolated and determined by spectral data as blumenol A and grasshopper ketone. Blumenol A and grasshopper ketone, respectively, inhibited the growth of cress shoots and roots at concentrations greater than 10 and 30 μmol/L. The concentrations required for 50% growth inhibition on cress roots and shoots were 84 and 27 μmol/L, respectively, for blumenol A, and 185 and 76 μmol/L, respectively, for grasshopper ketone. These results suggest that blumenol A and grasshopper ketone may contribute to the growth inhibitory effect of Awaakamai and may play an important role in the allelopathy of Awaakamai.

Original languageEnglish
Pages (from-to)682-685
Number of pages4
JournalJournal of Plant Physiology
Issue number7
Publication statusPublished - 2012 May 1


  • Allelopathy
  • Echinochloa
  • Growth inhibitor
  • Japanese traditional rice
  • Phytotoxin
  • Weed management

ASJC Scopus subject areas

  • Physiology
  • Agronomy and Crop Science
  • Plant Science


Dive into the research topics of 'Identification of two phytotoxins, blumenol A and grasshopper ketone, in the allelopathic Japanese rice variety Awaakamai'. Together they form a unique fingerprint.

Cite this