title: Isolation and identification of an allelopathic substance from peel of Citrus junos.
abstract: The inhibitory effect of Citrus junos peel on plant growth using lettuce (Lactuca sativa L.) as a bioassay material was investigated, since the powder of the peel had been found to inhibit growth of weeds. Basic, neutral and acidic fractions were separated from the aqueous fraction obtained from the methanol extract of C. junos peel. All fractions inhibited the growth of lettuce seedlings, but by far the greatest inhibition was observed with the neutral fraction. Thus, the latter was further purified and an allelopathically active substance was isolated. The structure of the substance was determined from high-resolution MS and 1H and 13C NMR spectral data as abscisic acid-beta-D-glucopyranosyl ester (ABA-GE). ABA-GE inhibited hypocotyl and root growth of lettuce seedlings at concentrations greater than 0.3 microM, and the concentrations for 50% inhibition of hypocotyl and root growth were 2.3 and 1.4 microM, respectively. The effectiveness of ABA-GE on inhibition of growth and the occurrence of ABA-GE in the peel itself suggested that ABA-GE may play an important role in the allelopathic potential of C. junos peel. The peel may be potentially useful for weed management in a field setting.
authors.affiliation: Department of Biochemistry and Food Science, Faculty of Agriculture, Kagawa University, Miki, Kagawa, Japan. hisashi@ag.kagawa-u.ac.jp
authors.forename: Hisashi
authors.initials: H
authors.lastname: Kato-Noguchi
authors.forename: Yukitoshi
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Toshihumi
authors.initials: T
authors.lastname: Murakami
authors.forename: Shosuke
authors.initials: S
authors.lastname: Yamamura
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Fujihara
mesh_terms: D000040:Abscisic Acid / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D005591:Chemical Fractionation / Q000379:methods; D002957:Citrus / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D018546:Hypocotyl / Q000187:drug effects / Q000254:growth & development; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development; D019906:Nuclear Magnetic Resonance, Biomolecular; D010937:Plant Growth Regulators / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development
chemical_list: D005960:Glucosides; D010937:Plant Growth Regulators; D000040:Abscisic Acid