Nobukatsu Katsui

Antifungal compounds from Dioscorea batatas inoculated with Pseudomonas cichorii

Abstract An induced and six preformed antifungal compounds were isolated from Chinese yam ( Dioscorea batatas ) inoculated with the bacterium Pseudomonas cichorii . The induced compound, a phytoalexin, was identified as dihydropinosylvin. The preformed compounds were characterized as oxygenated bibenzyls and phenanthrenes.

Isolation of three novel sulphur-containing phytoalexins from the chinese cabbage Brassica campestris L. ssp. pekinensis(cruciferae)

Inoculation of Chinese cabbage heads with the bacterium Pseudomonas cichorii induced the production of three major phytoalexins named methoxybrassinin (1), brassinin (2), and cyclobrassinin (3), whose structures have been elucidated on the basis of spectroscopic studies and synthesis.

Two polyacetylenic phytoalexins from Arctium lappa

Abstract Treatment of sliced burdock root tissue with copper (II) sulphate stimulated phytoalexin formation. Two were isolated and characterized as ( S )-12,1

Isolation and structure of lettucenin A, a novel guaianolide phytoalexin from Lactuca sativa var. capitata(Compositae)

Inoculation of lettuce (Lactua sativa var. capitata) leaves with the pathogenic bacterium Pseudomonas cichorii induced the production of two antifungal sesquiterpenes, costunolide and anew compound named lettucenin A, whose structure has been elucidated on the basis of spectroscopic studies.

Structure of rishitin M-1 and M-2, metabolites of rishitin in healthy potato tuber tissues

The title compounds metabolites of rishitin (1a) in healthy potato tuber tissues, are determined to possess structures (2a) and (3a).

Metabolism of rishitin. The NIH-like shift in formation of rishitin M-2

Feeding experiments with (–)-[12,12-2H2]rishitin (1-D) in healthy potato tuber tissues indicated that metabolism of (1) into rishitin M-2 (3) proceeded with a stereospecific 1,2-migration of an olefinic hydrogen at C-12 of (1) in contrast with formation of rishitin M-1 (2) by direct oxygenation on C-13 of (1).

Biosyntesis from solavetivone of the phytoalexin rishitin potato. Implicit role of solavetivone as an activator

The biosynthetic production of rishitin from solavetivone via lubimin oxylubimin has been established on the basis of experiment with (±)-[8,8-2H2]solavetivone.