Katsuhiro Konno

Isolation and structure of aromelic acid A and B. New kainoids of clitocybe acromelalga

Abstract A minute amount of the new kainic acid-like amino acids, acromelic acid A (ca. 110 μg) and B (ca. 40 μg), was isolated from the poisonous mushroom Clitocbe acromelalga and their structures were inferred to be 1 and 2 respectively by spectral analyses.

Synthesis of acromelic acid A, a toxic principle of clitocybe acromelalga.

Abstract Acromelic acid A, a toxic principle of Clitocybe acromelalga , was synthesized from l -α-kainic acid. The synthesis established the previously inferred structure, and determined the absolute configuration as shown by 1 .

Clitidine, a new toxic pyridine nucleoside from clitocybe acromelalga

Abstract From a poisonous mushroom, Clitocybe acromelalga , a new nucleoside clitidine ( 1 ) was isolated as a toxic principle. The structure was deduced to be 1 from spectral data and chemical degradation studies. Synthesis of 1 through condensation of methyl 4-aminonicotinate with 3, 5-di- O -benzoyl-D-ribofuranosyl chloride confirmed the structure, including absolute configuration.

Clithioneine, an amino acid betaine from Clitocybe acromelalga

Abstract A new amino acid betaine, clithioneine, was isolated from a poisonous mushroom Clitocybe acromelalga, and its structure was established on the basis of spectral analyses and chemical degradation studies.

Isolation and structure of clithioneine, a new amino acid betaine from clitocybe acromelalga.

A new amino acid betalne clithioneine was isolated from Clitocybe acromelalga. The structure was determined as 1 by spectral analyses and chemical degradations.

4-Aminopyridine-2,3-dicarboxylic acid from Clitocybe acromelalga

Abstract A new pyridine derivative, 4-aminopyridine-2,3-dicarboxylic acid, was isolated from Clitocybe acromelalga, and its structure was determined by spectral and synthetic methods.

A new pyridine synthesis starting from α, β-unsaturated carbonyl compounds

Abstract A new and mild synthetic method of substituted pyridines from α, β-unsaturated carbonyl compounds through a sequence involing (1) 1, 4-conjugate addition of thiophenol (2) condensation with a methylene ketone (3) Pummerer rearrangement to an unsaturated 1, 5-dicarbonyl compound (4) treatment with ammonia is described.