Takane Fujimori

Phytotoxicity of three lactones from nigrospora Sacchari

Abstract A culture broth of Nigrospora sacchari showed strong herbicidal activity in treatment of intact greenhouse-grown plants. Three lactones were isolated from the culture broth. The major compound, which exhibited the most significant effect of the fungal metabolites in the assay procedures, was identified as (+)-phomalactone, 6-(1-propenyl)-5,6-dihydro-5-hydroxy-2H-pyran-2-one. Others were 5-[1-(1-hydroxybut-2-enyl)]-furan-2-one and 5-[1-(1-hydroxybut-2-enyl)]-dihydrofuran-2-one. These fungal metabolites were investigated for their herbicidal effects in an electrolyte leakage assay and the results obtained appeared to indicate that the herbicidal damage was caused by cellular disruption. Phomalactone caused remarkable and rapid electrolyte leakage on cucumber cotyledon discs at concentrations higher than 50 ppm.

Stress compounds in the leaves of Nicotiana undulata induced by TMV inoculation

Abstract In leaves of Nicotiana undulata inoculated with TMV, 19 sesquiterpenoids were detected as stress compounds. Among them, dehydrocarissone, capsidiol 3-acetate, aubergenone, 4- epi -aubergenone, trans -dihydrocarissone, 1,2-dehydro-α-cyperone and 3- epi -3-hydroxysolavetivone are novel tobacco stress compounds.

Glucosides of ionone-related compounds in several nicotiana species

Abstract The β-glucosides of 3-oxo-α-ionol and 5,6-epoxy-5,6-dihydro-3-hydroxy-β-ionol were isolated from fresh leaves of Nicotiana rustica. Two or more of the glucosides of 3-oxo-α-ionol, 5,6-epoxy-5,6-dihydro-3-hydroxy-β-ionol, 3-hydroxy-β-damascone, blumenol A, 4-(3-hydroxybutylidene)-3,5,5-trimethyl-2-cyclohexenl-one and blumenol C were shown to be present and the amounts measured in N. alata, N. repanda, N. rustica, N. undulata, N. accuminata, N. sylvestris and N. tabacum. No glucosides were detected in N. paniculata.

A malonylated anthocyanin and flavonols in blue Meconopsis flowers

The structures of the major anthocyanin and two flavonols from the blue flowers of Meconopsis were identified by NMR spectroscopy as being cyanidin 3-O-[(6-O-malonyl-2-O-B-D-xylopyranosyl)-beta-D-glucopyranoside]-7-O-beta-D-glucopyranoside, kaempferol 3-O-(6-O-beta-D-glucopyranosyl)-beta-D-glucopyranoside and kaempferol 3-O-(6-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside respectively.

Sesquiterpenoid stress compounds from Nicotiana species

Abstract Solavetivone, 3-hydroxysolavetivone, solanascone, phytuberin and phytuberol were identified as stress compounds in leaves of Nicotiana tabacum cv Samsun NN. N. sylvestris , which is the maternal progenitor of N. tabacum , produced all the above compounds except 3-hydroxysolavetivone. In the F 1 , hybrid of N. tabacum and N. glutinosa , all the stress compounds produced by N. tabacum and N. glutinosa , respectively, were accumulated.

Nigrosporins A and B, New Phytotoxic and Antibacterial Metabolites Produced by a Fungus Nigrospora oryzae

Nigrosporin A and B, two new phytotoxic and antibacterial metabolites were isolated from a culture filtrate of Nigrospora oryzae. The active principles were absorbed on XAD-2 resin and purified by successive ODS-HPLC. The structures were identified by spectroscopic and derivatization analysis as naphthoquinone derivatives. The substances showed phytotoxic activities, such as root elongation inhibition, necrotic effects, oxygen evolution inhibition, starch synthesis inhibition, and CO2 fixation inhibition at concentrations of 10-100 ppm. They also showed growth inhibition activity against Bacillus subtilis in a disc diffusion assay as well as when compared with streptomycin.

Isolation of (−)-1,2-dehydro-α-cyperone and solavetivone from Lycium chinense

Abstract The investigation of volatile components of Lycium chinense afforded (−)-1,2-dehydro-α-cyperone and solavetivone. (−)-1,2-Dehydro-α-cyperon

Accumulation of phytuberin and phytuberol in tobacco callus inoculated with Pseudomonas solanacearum or Pseudomonas syringae pv. Tabaci

Abstract Tobacco callus tissues inoculated with Pseudomonas solanacearum or Pseudomonas syringae pv. tabaci accumulated phytuberin and phytuberol. Accumulation of the two sesquiterpenoids was dependent upon: the source (cultivar) of the explant; the number of transfers; the period which had elapsed after transfer; the bacterial species, and the time after inoculation.

Stress compounds in tobacco callus infiltrated by Pseudomonas solanacearum

Abstract Two sesquiterpenoids, phytuberin and phytuberol, have been identified in tobacco callus infiltrated by Pseudomonas solanacearum .

A malonylated anthocyanin and flavonols in the blue flowers of Meconopsis

Abstract The blue Himalayan poppies, Meconopsis horridula, M. grandis and M. betonicifolia, contain cyanidin 3-malonylsambubioside 7-glucoside as the anthocyanin. They also contain large amounts of kaempferol 3-gentiobioside and very small amounts of kaempferol 3-xylosylgentiobioside. The ratio of flavonol to anthocyanin was found to be 5.6:1, suggesting that the flavonol plays a role as a co-pigment in the blueing of Meconopsis flowers.