Katsuyoshi Matsunami

Absolute configuration of (+)-pinoresinol 4- O -[6″- O -galloyl]- β -d-glucopyranoside, macarangiosides E, and F isolated from the leaves of Macaranga tanarius

A lignan glucoside, (+)-pinoresinol 4-O-[6-O-galloyl]-beta-D-glucopyranoside (1), and two megastigmane glucosides, named macarangiosides E and F (2,3), together with 15 known compounds (4-18) were isolated from leaves of Macaranga tanarius (L.) Müll.-Arg. (Euphorbiaceae). Their structures were elucidated by spectroscopic and chemical analyses. In addition, the absolute stereochemistry of macarangiosides B and C isolated previously from the same plant was also determined for the first time. Compounds 1 and 2 were galloylated on glucose and possessed potent DPPH radical-scavenging activity.

Macaflavanones A-G, Prenylated Flavanones from the Leaves of Macaranga tanarius

Phytochemical investigation of leaves of Macaranga tanarius resulted in the isolation of seven new prenylated flavanones, macaflavanones A-G (1-7), along with two known compounds, nymphaeol C (9) and the diterpene kolavenol. The structures of the new compounds were elucidated by means of a combination of spectroscopic methods and chemical conversion. The absolute structure of tanariflavanone B (8), isolated from the title plant, was also resolved. The cytotoxic activities of isolated flavanones were assayed using two cell lines, with macaflavanone G (7) being the most active compound in each case.

Conjugates of an abscisic acid derivative and phenolic glucosides, and a new sesquiterpene glucoside from Lindera strychnifolia

Three conjugates of the abscisic acid derivative (2Z,4E)-5-[(1S,3S,5R,8S)-3,8-dihydroxy-1,5-dimethyl-7-oxo-6-oxabicyclo[3.2.1]octan-8-yl]-3-methylpenta-2,4-dienoic acid and phenolic glucosides (1–3), and an eremophilane-type sesquiterpene glucoside (4), along with ten known compounds, were isolated from the roots of Lindera strychnifolia. The structures of all compounds were elucidated by means of spectroscopic analysis, and by application of the modified Mosher’s method for the methyl ester of the abscisic acid derivative and the octant rule for 4.

Lignan and neolignan glucosides, and tachioside 2′- O -4″- O -methylgallate from the leaves of Glochidion rubrum

Thirteen compounds (1–13) were isolated from a MeOH extract of leaves of Glochidion rubrum. The structures of four new compounds were elucidated to be (−)-isolariciresinol 2a-O-β-d-glucopyranoside (1), (7R,8S)- and (7R,8R)-4,7,9,9′-tetrahydroxy-3,3′-dimethoxy-8-O-4′-neolignan 7-O-β-d-glucopyranosides (2 and 3, respectively), and tachioside 2′-O-4″-O-methylgallate (4) on detailed inspection of one- and two-dimensional NMR spectral data.

BUMALDOSIDES A, B AND C FROM THE LEAVES OF STAPHYLEA BUMALDA

Two new aliphatic diglycosides and a phenolic glucoside (4, 5 and 7) have been isolated from leaves of Staphylea bumalda DC., together with three known compounds, benzyl and phenethyl alcohol glycosides (1 and 2), and zingerone β-D-glucopyranoside (6). 2-Ethyl-3-methylmaleimide N-glucopyranoside (3) was first isolated as a free form. Their structures were determined on the basis of spectroscopic analysis.