Ko Kaneko

Origin of nitrogen in the biosynthesis of solanidine by Veratrum grandiflorum

Abstract Veratrum plants accumulate verazine as the major alkaloid in the rhizome during the dormant stage 4 months after cold treatment. The quantitative c

Dormantinol, a possible precursor in solanidine biosynthesis, from budding Veratrum grandiflorum

Abstract A new sapogenin, dormantinol, was isolated from budding Veratrum , and identified as (25 S )-cholest-5-ene-3β,22α,26-triol by spectral analysis and its synthesis from dormantinone. Cholesterol was also identified in the budding Veratrum .

Biosynthesis of C-nor-D-homo-steroidal alkaloids from acetate-1-14C, cholesterol-4-14C and cholesterol-26-14C in Veratrum grandiflorum

Abstract The incorporations of acetate-1- 14 C, cholesterol-4- 14 C, and cholesterol-26- 14 C into the jerveratrum and ceveratrum alkaloids were shown in Veratrum grandiflorum Loesen. fil. The biosynthetic activity of veratramine was affected by the concentration of jervine in the plant organ which synthesizes the steroidal alkaloids.

Biosynthesis of rubijervine in Veratrum grandiflorum

Abstract The rhizome of dormant Veratrum grandiflorum accumulated hakurirodine, a new 22,26-epiminocholestane alkaloid. This alkaloid, derived from verazine but not from etioline, was found to be a key intermediate in the biosynthesis of rubijervine.

Chuanbeinone, a novel D/E cis-(22R,25S)-5α-cevanine alkaloid from chinese herbal drug, chuan-bei-mu

Abstract A novel D/E cis (22R,25S)-20-deoxy-5α-cevanine alkaloid, chuanbeinone, was isolated from the herbal drug of Fritillaria plant (“chuan-bei-mu” in Chinese), and its absolute configuration was confirmed by X-ray crystallographic analysis.

Camtschatcanidine, an alkaloid from Fritillaria camtschatcensis

Abstract From the hydrolysed glycoalkaloid fraction from bulbs of mature Fritillaria camtschatcensis in addition to already reported alkaloids a new solanidanine alkaloid, 22 R ,25 S -solanid-5-ene-3β,27-diol (camtschatcanidine), was isolated and its structure elucidated by spectral analysis and its conversion to solanidine. Also veralkamine was identified from the same plant.

11-Deoxojervine as a precursor for jervine biosynthesis in Veratrum grandiflorum

Abstract Experimental data show that 11-deoxojervine- 14 C (I) is converted into jervine (II) but not to veratramine (III) in the growing Veratrum plant. Moreover, non-radioactive 11-deoxojervine (I) inhibits the incorporation of acetate-1- 14 C into jervine.

Two steroidal alkaloids, hapepunine and anrakorinine, from the mature Fritillaria camtschatcensis

Abstract After acid hydrolysis of a glycosidic fraction from the aerial parts of Fritillaria camtschatcensis , in addition to solanidine, tomatidenol, and solasodine, two N -methyl-22,26-epiminocholestenes, hapepunine and anrakorinine, were isolated and their structures elucidated by physical and chemical methods.

Structure of barogenin from Solanum tuberosum

Abstract The budding tuber of Solanum tuberosum accumulated barogenin. Its structure was determined by chemical and spectroscopic studies as (25S)-3β, 26-dihydroxy-cholest-5-ene-16,22-dione, the (25S)-epimer of kryptogenin. The biogenetic relationship between barogenin and spirostanols is discussed.

13C-NMR studies on the cevanine alkaloids : the application of 13C-NMR spectrum for structure elucidation of new alkaloids, baimonidine and isoverticine

Abstract The 13 C-NMR spectra of seven cavanine alkaloids isolated from Veratrum and Fritillaria plants were measured and their signals were assigned, and these results were applicated for structure elucidation of two new cevanine alkaloids, baimonidine and isoverticine, isolated from mature Fritillaria verticillata.