The soil fungus Talaromycesjavus (Klocker) Stolk and Samson is an effective biological control for Verticillium wilt of eggplant (Solanum melongena L.), a disease caused by the fungus Verticillium dahliae Kleb. The organic soluble metabolites produced when the fungus is grown in liquid still culture include D-glucono-1 ,4-lactone (I), 5-hydroxymethylfurfural (S), the previously unreported tetraketides, 4,6-dihydroxy-5-methylphthalide (3) and methyl 4-carboxy-5-hydroxyphthalaldehydate (8), a hexaketide, 7-hydroxy-2,5-dimethylchromone (6), and a metabolite believed to be 3-hydroxymethyl-6,8-dimethoxycoumarin (10). A number of higher order polyketides have been isolated including altenusin (ll), dehydroaltenusin (12), and the previously unreported desmethyldehydroaltenusin (14). A structurally and biosynthetically interesting spirocyclic metabolite, which we have named talaroflavone (16), as well as a related compound, deoxytalaroflavone (18), have also been obtained. Chem. 68, 2085Chem. 68, (1990.Le champignon du sol Talaromycesjavus (Klocker) Stolk et Samson contr6le biologiquement et d'une f a~o n efficace la flktrissure par le Verticillium de l'aubergine (Solanum melongena L.), une maladie causCe par le champignon Verticillium dahliae Kleb. Les metabolites organiques solubles qui sont produits lorsqu'on fait croitre le champignon dans un milieu de culture comprennent : la ~-g l~~0 n 0 -1 , 4 -l a~t 0 n e (I), le 5-hydroxyrnCthylfurfura1 (S), les tCtrakCtides 4,6-dihydroxy-5-mCthylphtalide (3) et 4-carboxy-5-hydroxyphtalaldChydate de mCthyle (8) qui n'avaient pas Ct C rapportts anterieurement, un hexakktide, la 7-hydroxy-2,5-dimCthylchromone (6), ainsi qu'un mCtabolite que l'on croit Ctre la 3-hydroxymCthy1-6,8-dimCthoxycoumarine (10). On a aussi isole un certain nombre de polykCtides d'ordre plus ClevC, dont I'altCnusine (11), la dChydroaltCnusine (12) ainsi que la desmCthyldChydroaltCnusine (14) qui n'avait pas Ct C rapportCe antkrieurement. On a aussi obtenu un mCtabolite spirocyclique, intCressant d'un point de vue structural et biosynthetique, que l'on a appelC talaroflavone (16) ainsi qu'un composC apparentC, la dCsoxytalaroflavone (18).Mots clks : Talaromycesjavus, metabolites de champignon, talaroflavone, 4,6-dihydroxy-5-mkthylphtalide.[Traduit par la revue]

In an attempt to assess the synthetic utility of oxoiminium ions as oxidizing agents and to delineate their reaction mechanisms, we reacted l-oxo-2,2,6,6-tetramethylpiperidinium chloride (1) with several MlV-dialkylanilines. With jVJV-dimethylaniline the only basic product was AT-methylaniline while JV-methylformanilide was the only neutral product. The relative amounts of base and neutral product proved to be sensitive to the amount of water present in the reaction medium. With jV-alkyl-jV-methylanilines, the basic products were N-alkylanilines from exclusive loss of the IV-methyl group. The neutral products were the IV-alkylformanilides. The alkyl groups studied were ethyl, n-butyl, isopropyl, and benzyl. With IV-tert-butyl-lV-methylaniline, there was no observed reaction, and jV^V-diethylaniline was found to be significantly less reactive than JVJV-dimethylaniline. This study has shown that 1 is selective in N-demethylation of anilines in the presence of other alkyl groups either on the same nitrogen or on separate nitrogens. These results have been interpreted in terms of important steric interactions resulting from formation of an adduct en route to an intermediate iminium ion.Oxoiminium salts are an interesting but relatively unexplored class of oxidizing agents in which only a few examples1-3 have been isolated and characterized. Of these, the l-oxo-2,2,6,6-tetramethylpiperidinium ion (1) is the first to be reported1 23 4and is the most studied. The chloride

. Can. J. Chem. 68, 2095Chem. 68, (1990. The soil fungus Talaromycesjavus (Klocker) Stolk and Samson is an effective biological control for Verticillium wilt of eggplant (Solanurn melongena L.), a disease caused by the fungus Verticilliurn dahliae Kleb. The water soluble metabolites isolated from the broth when the fungus is grown in liquid still culture, hydroxymethylmaltol (I), 5,6-dihydro-3,5-dihydroxy-6-hydroxymethyl-2H-pyran-2-one (3), and D-glucono-l,4-lactone (5), do not show antifungal activity against V. dahliae; however, hydrogen peroxide displays this inhibition. This peroxide has been detected in the T.javus broth and it, together with 5, is the product of the glucose oxidase catalyzed oxidation of D-glucose. The results of the search for this antifungal activity are presented. [l-13C] Labelled sodium acetate was utilized as a precursor for studying the biosynthesis of the T. javus metabolites 4,6-dihydroxy-5-methylphthalide (7), methyl 4-carboxy-5-hydroxyphthalaldehydate (a), and talaroflavone (9). The incorporation of label into these compounds is discussed.

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