Rie Kakuda

Secoiridoid glycosides from the flower buds of Lonicera japonica

Two secoiridoid glycosides, loniceracetalides A and B, were isolated in very small amounts, together with 10 known iridoid glycosides, from the flower buds of Lonicera japonica. The structures of loniceracetalides A and B were determined by spectroscopic analysis.

Triterpenoids from Gentiana scabra

Five triterpenoids, (20S)-dammara-13(17),24-dien-3-one, (20R)-dammara-13(17),24-dien-3-one, chirat-16-en-3-one, chirat-17(22)-en-3-one and 17beta,21beta-epoxyhopan-3-one, were isolated from the rhizomes and roots of Gentiana scabra together with five known ones, chiratenol, hop-17(21)-en-3-one, hop-17(21)-en-3beta-ol, lupeol and alpha-amyrin. The structures of new compounds were elucidated on the basis of spectroscopic studies.

New physiological function of secoiridoids: neuritogenic activity in PC12h cells

Previously, we have reported that geniposide isolated from an extract of Gardenia fructus has neuritogenic activity in PC12h cells, a subclone of rat pheochromocytoma cells. Furthermore, we have indicated that several geniposide-related iridoid compounds also had similar potent neuritogenic activity. In this study, we have examined the effects of various secoiridoid compounds [K-1, sweroside; K-2, swertiamarin; K-3, gentiopicroside; K-4, 6′-O-β-d-glucopyranosylsweroside; K-5, 6′-O-β-d-glucopyranosylgentiopicroside; K-6, 6′-O-β-d-glucopyranosylswertiamarin; K-7, 5′-O-β-d-glucopyranosylamarogentin; K-8, 5′-O-β-d-glucopyranosylamaroswertin; H-1, n-butyl vogeloside; H-2, n-butyl epivogeloside; H-3, (7S)-secologanin butyl methyl acetal; H-4, (7R)-secologanin butyl methyl acetal; H-5, secologanin dimethyl acetal] isolated from various medicinal herbs. The secoiridoids H-1, H-2, H-3, H-4, and H-5 induced significant neurite outgrowth. Among these H-series compounds, H-2 was the most potent neuritogenic compound. Among the K-series compounds, K-1, K-2, K-3, and K-8 showed the most potent activity. These results suggest that secoiridoids have neuritogenic activity in PC12h cells and that these secoiridoid compounds are promising starting compounds for the development of neurotrophic factor-like and iridoid compounds.

イボタノキ属植物の成分研究(第19報) : トウネズミモチの葉の新規イリドイド配糖体の構造

Two new iridoid glucosides, named iso-8-epikingiside and 8-demethyl-7-ketologanin, were isolated together with 8-epikingiside, kingiside, ligustroside, 10-hydroxyligustroside, ligustaloside A and ligustaloside B from the leaves of Ligustrum lucidum AIT. (Oleaceae). The stereochemical structures of these new compounds were elucidated on the basis of spectroscopic evidence.

Glycosides from whole plants of Glechoma hederacea L

From dried whole plants of Glechoma hederacea L. (Labiatae), seven known glycosides were isolated and identified: (6R,7E,9R)-megastigma-4,7-dien-3-one 9-O-β-d-glucopyranoside (1), apigenin 7-O-neohesperidoside (2), chrysoeriol 7-O-neohesperidoside (3), (+)-pinoresinol 4,4′-bis-O-β-d-glucopyranoside (4), (+)-syringaresinol 4,4′-bis-O-β-d-glucopyranoside (5), (+)-lariciresinol 4,4′-bis-O-β-d-glucopyranoside (6), and (7R,8R)-threo-7,9,9′-trihydroxy-3,3′-dimethoxy-8-O-4′-neolignan 4-O-β-d-glucopyranoside (7).

Secoiridoid glycosides from the leaves of Hydrangea macrophylla subsp. serrata

Seven secoiridoid glycosides, secologanin dimethyl acetal (1), n-butyl vogeloside (2), n-butyl epi-vogeloside (3), (7R)-n-butyl morroniside (4), hydrangenoside A (5), hydrangenoside C (6), and hydrangenoside A dimethyl acetal (7), have been isolated from the leaves of Hydrangea macrophylla subsp. serrata (Thunb.) Makino (Saxifragaceae). The structures were elucidated on the basis of spectral data.

Macropyllanosides A-D, secoiridoid glycosides from Hydrangea macrophylla subsp. serrata

- Four new secoiridoid glycosides, named macrophyllanosides A - D, were isolated from the leaves of Hydrangea macrophylla subsp. serrata. Their structures have been determined by spectroscopic and chemical means.