Reiko Matsuda

Riccardin C, a novel cyclic bibenzyl derivative from Reboulia hemisphaerica

Abstract Riccardin C, a novel cyclic bibenzyl derivative with a biphenyl ether and biphenyl linkages, and the previously known ent-aristolone have been isolated from the liverwort Reboulia hemisphaerica. Riccardin C trimethyl ether was identical to the dimethoxy derivative of riccardin A isolated from the liverwort Riccardia multifida.

Preparation of biologically active substances and animal and microbial metabolites from menthols, cineoles and kauranes

Abstract Six monoterpenoids, l-menthol, l-menthyl acetate, iso-menthol, neo-menthol, 1,4-cineole and 1,8-cineole and one diterpene hydrocarbon, ent-kaurene were oxidized by meta-chloroperbenzoic acid or dry ozone to give various hydroxylated products and their structures elucidated by NMR spectroscopy. Some hydroxylated menthols showed plant growth inhibitory and strong mosquito repellent activity. Among the hydroxylated cineoles, microbial and animal metabolites of cineoles were included. From ent-kauranes, a plant growth inhibitory diterpene alcohol, (−)-16α-hydroxy kaurane was obtained along with 16α-kauran-13α-ol.

Mono- and sesquiterpenoids from Hydrocotyle and Centella species

Abstract Hydrocotyle sibthorpioides , H. maritima and Centella asiatica were investigated for their ter- penoid constituents. The major component of H. sibthorpioides and H. maritima is trans - β- farnesene . The latter species also elaborates α-terpinene and thymol methyl ether in respectable amount. The sesquiterpenoid constitution of C. asiatica is rather similar to H. maritima . Possible allelopathy between H. sibthorpioides and a liverwort is suggested.

Terpenoids and bibenzyls of 25 liverwort Frullania species

Abstract Twenty-five Frullania species (liverworts) were chemically investigated. Fourteen species produce allergy-inducing sesquiterpene lactones. Eighteen species contain bibenzyls. The sesquiterpene lactones and bibenzyls are obtained as the major components and they are valuable chemosystematic markers of Frullania species. On the basis of their chemical constituents, Frullania species can be divided into five chemotypes: sesquiterpene lactone-bibenzyl type; sesquiterpene lactone type; bibenzyl type; monoterpene type and cyclocolorenone type.

Distribution of novel cyclic bisbibenzyls in Marchantia and Riccardia species

Abstract Marchantins A, B and C, three new cyclic bisbibenzyls with two ether links have been isolated from the liverworts Marchantia polymorpha, M. paleacea var. diptera and M. tosana (Marchantiales). Riccardia multifida (Metzgeriales) also contained two new cyclic bisbibenzyls, riccardins A and B, with an ether and a biphenyl link. The presence of cyclic bisbibenzyls has not been confirmed in Dumortiera hirsuta and Preissia quadrata (Marchantiales). The present chemical data support that D. hirsuta and P. quadrata are not closely allied to Marchantia by flavonoid chemistry and some species of Marchantiales have close affinities to those of Metzgeriales.

Sesquiterpenoids from Chiloscyphus, Clasmatocolea and Frullania species☆

Abstract Eight liverworts, Chiloscyphus polyanthus and Clasmatocolea vermicularis (Lophocoleaceae), Frullania apiculata, F. clavata, F. folciloba, F. gaudichaudii, F. serrata and F. ternatensis (Frullaniaceae) were chemically investigated. ent-7,8-Eudesmanolides are important chemical markers of C. polyanthos and C. vermicularis. The latter species also produces 6,7-eudesmanolides which are the chemical markers of Frullania species. C. polyanthos and C. vermicularis are chemically quite close to some Diplophyllum species belonging to Scapaniaceae. The structure of 5β-hydroxydiplophyllolide previously isolated from C. polyanthos was revised to ent-7α-hydroxydiplophyllolide by analysis of its 1H NMR spectrum. From the chemical constituents, the six Frullania species are classified to three chemotypes.

Mono- and sesquiterpenoids from Wiesnerella denudata

Abstract The characteristic pungency of the liverwort Wiesnerella denudata is due to a germacranolide, tulipinolide. In addition to the previously known sesquiterpene lactones, tulipinolide, zaluzanin C, zaluzanin D, 8α-acetoxyzaluzanin C and 8α-acetoxyzaluzanin D, a novel germacranolide, dihydrotulipinolide with a pseudoaxial configuration of the C-11 methyl bond has been isolated. Inhibitory activity against the germination and growth of roots of rice in the husk is due to the guaianolides. The fragrant odor of W. denudata is responsible for the high content of monoterpenoids, particularly, (+)-bornyl acetate.

Cuparane- and isocuparane-type sesquiterpenoids in liverworts of the genus Herbertus☆

Abstract Canadian and Japanese Herbertus aduncus , Japanese H. sakuraii and Colombian H. subdentatus belonging to the Jungermanniales (Hepaticae) were chemically investigated. The previously known entcuparane- and novel isocuparane-type sesquiterpenoids are the major components which are of importance as chemical markers in the Herbertaceae.

Hydroxylation of dammarane type triterpenes with m-chloroperbenzoic acid

Abstract Dammaran-20(S)-ol and 20(S)-hydroxydammaran-3β-yl acetate were reacted with m -CPBA to give the corresponding 5α-ol, 7β-ol, 12β-ol, 25-ol, 2α-ol, and 5α,25-diol.

Hydroxylation of menthols and cineoles withm-chloroperbenzoic acid

Reaction of menthols and cineoles withm-chloroperbenzoic acid afforded tertiary, secondary, and primary alcohols, some of which were natural products having potent plant growth regulatory activity or were mammlianm metabolies.