Miyako Kusano

Nematicidal Alkaloids and Related Compounds Produced by the Fungus Penicillium cf. simplicissimum

A new nematicidal alkaloid, peniprequinolone (1), together with the known alkaloids penigequinolones A and B (2a, 2b), 3-methoxy-4-hydroxy-4-(4′-methoxyphenyl)quinolinone (3), and 3-methoxy-4,6-dihydroxy-4-(4′-methoxyphenyl)quinolinone (4), were isolated from Penicillium cf. simplicissimum (Oudemans) Thom. Cyclopenin (5) and a compound (6a/6b) structurally related to cyclopenin also were isolated from the fungus, and their structures were established by spectroscopic analysis. The biological activities of 1, 2, 3, 4, and 5 were examined by a bioassay with root-lesion nematodes.

Penigequinolones A and B, pollen-growth inhibitors produced by Penicilium sp., No. 410

Abstract Penigequinolones A and B were isolated from the mycelial mats of Penicillium sp. No. 410 as new pollen-growth inhibitors, and their structures were established by NMR studies.

BREVICOMPANINES A AND B : NEW PLANT GROWTH REGULATORS PRODUCED BY THE FUNGUS, PENICILLIUM BREVICOMPACTUM

New plant growth regulators, named brevicompanines A 1 and B 2, have been isolated from Penicillium brevicompactum, and their structures have been established by spectroscopic methods including 2D NMR. The biological activities of 1 and 2 have been examined using bioassay methods with lettuce and rice seedlings.

Aspterric Acid and 6-Hydroxymellein, Inhibitors of Pollen Development in Arabidopsis thaliana, Produced by Aspergillus terreus

Aspterric acid (1) and 6-hydroxymellein (2), inhibitors of pollen development in Arabidopsis thaliana, have been isolated fromthe fungus Aspergillus terreus. 1 and 2 inhibited the pollen development at concentrations of 38 and 52 μᴍ, respectively. The microscopic examination of pollen development suggested that the inhibition by the treatment with 1 caused at meiosis and the inhibition by the treatment with 2 caused at microspore stage. 1 and 2 could be useful agents for the molecular investigation of anther and pollen development in higher plants.

4-Hydroxykigelin and 6-Demethylkigelin, Root Growth Promoters, Produced by Aspergillus terreus

Root growth promoters, 4-hydroxykigelin (1) and 6-demethylkigelin (2), together with 6- hydroxymellein (3) were isolated from cultures of the fungus Aspergillus terreus and their structures were identified by spectroscopic analysis. The biological activities of the three dihydroisocoumarins, 1, 2, and 3, have been examined using a bioassay method with lettuce seedlings. Furthermore, interactions between the dihydroisocoumarins and indole-3-acetic acid against the root growth have been examined.

Simplicissin, a New Pollen Growth Inhibitor Produced by the Fungus, Penicillium cf. simplicissimum (Oudemans) Thom No. 410

A new pollen growth inhibitor, named simplicissin, was isolated from Penicillium cf. simplicissimum (Oudemans) Thorn No. 410, and its structure was established by spectroscopic methods including 2D NMR. The biological activities of the compound were examined by the bioassay methods involving tea pollen together with lettuce seedlings. The compound inhibited the growth of the tea pollen tube by 45% at a concentration of 3 mg/liter and showed complete inhibition at 10mg/liter.