Yoshiki Kashiwada

Galloyl and hydroxycinnamoylglucoses from rhubarb

Abstract A chemical examination of the commercial rhubarbs, produced in China, North Korea and Japan, has led to the isolation of five hydroxycinnamoyl and galloyl esters with glucose. Their structures were established on the basis of chemical and spectroscopic evidence as 1- o -galloyl-6- O -cinnamoyl-, 1,2-di- O -galloyl-6- O -cinnamoyl-, 1,2-di- O -galloyl-6- O - p -coumaroyl-, 1,6-di- O -galloyl-2- O - p -coumaroyl- and 1,2-di- O -galloyl-β- d -glucoses.

Galloylsucroses from rhubarbs

Abstract Chinese rhubarb yielded a new class of gallotannins having a sucrose core, while North Korean rhubarb was found to contain four gallotannins. On the basis of chemical and spectroscopic evidence, the structures of the gallotannins were established as 6′-O-,4′-O-, 6-O-, 1′-O- and 2-O-monogalloylsucrose, respectively.

Flavan-3-ol and proanthocyanidin allosides from Davallia divaricata

Abstract Four flavan-3-ol glycosides and three proanthoeyanidin glycosides have been isolated from the fern, Davallia divaricata , together with procyanidins B-1 and B-2 and a trimeric procyanidin. All of these glycosides have been shown to possess an allopyranose moiety. The structures were elucidated on the basis of chemical and spectroscopic evidence.

4-Carboxymethyl flavan-3-ols and procyanidins from Davallia divaricata.

Abstract A series of flavan-3-ols and procyanidins, possessing a carboxymethyl group, and a procyanidin tetramer have been isolated from the fern, Davallia divaricata . The structures were characterized on the basis of chemical and spectral evidence.

Cinncassiol E, A diterpene from the bark of Cinnamomum cassia

Abstract Cinncasiol E, a hexacyclic diterpene of a new skeletal type, was isolated from a fraction with antiallergic activity obtained from a water extract of Cinnamomi cortex. Its structure was deduced by spectroscopic methods.

Chromone glucosides from rhubarb

Abstract A chemical examination of Chinese rhubarb has led to the isolation of two new chromone glucosides. On the basis of chemical and spectroscopic evidence, their structures were established as aloesone 7- O -β- d -glucopyranoside and 2-methyl-5-(2′-oxo-4′-hydroxypentyl)-7-hydroxychromone 7- O -β- d -glucopyranoside.