Shigeru Ohmiya

N-Formylcytisine: A new alkaloid from Thermopsis chinensis

Abstract A new base have been isolated from Thermopsis chinensis along with N-methylcytisine, cytisine, anagyrine and lupanine. The new alkaloid have been shown to be N-formylcytisine.

Absolute configuration of (+)-5,6-dehydrolupanine, a key intermediate in biosynthesis of lupin alkaloids

Abstract (+)-5,6-Dehydrolupanine, a key intermediate in biosynthesis of lupin alkaloids, was isolated from Thermopsis chinensis . The absolute configuration of the compound was determined to be 7 R ,9 R ,11 R by chemical transformation to (−)-lupanine.

Entadamide B, a second new sulphur-containing amide from Entada phaseoloides

Abstract A second new sulphur-containing amide, entadamide B, has been isolated from the dry seeds of Entada phaseoloides Merr. together with entadamide A. Entadamide B was characterized by spectroscopic methods as N -(2-hydroxyethyl)-3,3- bis (methylthi and was synthesized in two steps from propiolic acid.

Lupin alkaloids from the seeds of Thermopsis lupinoides

Abstract A new lupin alkaloid, (+)-lupanine N -oxide, was isolated from the seeds of Thermopsis lupinoides together with nine known alkaloids. The structure of the new compound was determined by spectroscopic methods and chemical transformations.

(−)-3β-13α-dihydroxylupanine from cytisus scoparius

Abstract A new lupin alkaloid, (−)-3β,13α-dihydroxylupanine was isolated from Cytisus scoparius together with five known sparteine-type lupin alkaloids and tyramine. The absolute structure of the new alkaloid was confirmed by comparison of the natural product with the synthetic sample derived from (+)-13-hydroxylupanine. It was also shown that the alkaloid constituents of C. scoparius differed considerably in the aerial parts, flowers and seeds.

Glycosidic alkaloids from Lupinus hirsutus.

Abstract Two new glycosidic alkaloids, (-)-( trans -4′-α- l -rhamnosyloxycinnamoyl)epilupinine and (-)-( cis -4′-α- l - rhamnosyloxycinnamoyl)epilupinine, were isolated from the aerial parts of Lupinus hirsutus together with seven known alkaloids, (-)-multiflorine, (+)-ammodendrine, (+)-epilupinine, (+)-epilupinine N -oxide, (+)-( trans -4′- hydroxycinnamoyl)epilupinine, (+)-( cis -4′-hydroxycinnamoyl)epilupinine and (+)-( trans -4′-hydroxy-3′- methoxycinnamoyl)epilupinine. The structures of the new compounds were determined by spectroscopic methods and by chemical transformation. The distribution of these alkaloids in flowers, leaves and stems, roots, and nodules of the plant was also clarified.

(+)-11-oxocytisine, a lupin alkaloid from leaves of sophora secundiflora

Abstract A new lupin alkaloid, (+)-11-oxocytisine (1), was isolated from the leaves of Sophora secundiflora together with (−)-anagyrine, (−)-N-methylcytisine, (−)-baptifoline, (−)-N-formylcytisine, (−)-N-acetylcytisine and (−)-cytisine. The structure of the new alkaloid (1) was presumed to be (+)-11--oxocytisine on the basis of its spectroscopic data.

Lupin alkaloids from flowers of Echinosophora koreensis

Abstract (−)-Methyl 12-cytisineacetate (2) was isolated from methanol extracts of fresh flowers of Echinosophora koreensis together with seven known lupin alkaloids. Ethyl 12-cytisineacetate (3) was also isolated from ethanol extracts of the same flowers. Compounds 2 and 3 were artifacts and (−)-12-cytisineacetic acid (4) is assumed to be the principal source of 2 and 3. The variations in alkaloid content during growth of the flowers and the seedlings were also examined.

Isolation of (+)-maackiamine (norammodendrine) from the flowers of Maackia amurensis

Abstract A new natural alkaloid, (+)-maackiamine, was isolated from the flowers of Maackia amurensis var. buergeri together with 10 known alkaloids. The structure of the new natural compound was determined as 1-acetyl-1,2,3,4-tetrahydro-5-(2′-pyrrolidinyl)pyridine by spectroscopic methods