Über die Gerbstoffe aus dem Holz der Edelkastanie und der Eiche, II. Die Isolierung von Castalagin, Vescalagin, Castalin und Vescalin

Abstract

Durch Chromatographie an Cellulosepulver gelang es, aus dem Gesamtgerbstoff des Edelkastanienholzes (Custanea sativa) und des Eichenholzes (Quercus sesselijlora) vier chemisch einheitliche Verbindungen abzutrennen, die als Castalagin, Vescalagin, Castalin und Vescalin bezeichnet werden. -Castalagin und Vescalagin sind kristallisiert und besitzen die gleiche Summenformel. Castalagin liefert bei der Hydrolyse Ellagsaure und Castalin, Vescalagin ergibt hierbei Ellagsaure und Vescalin. Auch Castalin ist kristallisiert und isomer mit Vescalin. Beim Erhitzen in waiBriger Losung wandeln sich Castalagin in Vescalagin und Castalin in Vescalin um.

Influence of oak wood polyphenols on cysteine, homocysteine and glutathione total levels and PON1 activities in human adult volunteers – a pilot study

“…Figure 1), which were originally isolated and described by Mayer et al (1967). Roburins and grandinin are dimers of these compounds or differ by the presence of a pentose substituent.…”

Vegetable Tannins

“…Fruit bearing plants have proved to be particularly rich sources of oligomeric procyanidins and both chemical and biochemical investigations have concentrated on the four major dimeric procyanidins (B-1 -B-4, 50 -53) which have been obtained from fruit, fruit pods, seeds and seed shells of diverse plant types. The procyanidins occur free and unglycosylated and almost invariably with one or both of the flavan-3-ols, (+)-catechin (3) or (-)-epicatechin (54). The principal exceptions to this generalisation are the procyanidins of the Palmae, discovered by Marini-Bettolo and his collaborators 81 , which are found in association with the diastereoisomeric flavan-3-ol, (+)-epicatechin.…”

“…The carbocations (56,57) would then be formed by 'leakage' of the hybrid ion (72 a or b) from the active site of the enzyme, and, it is postulated, react with the final reduction product (3,54) in the manner already prescribed. Four distinctive and biosynthetically homogeneous situations are possible and are listed, Figure 9.…”

Quercus spp. (Oak): In Vitro Culture and Production of Tannins

“…(Fig. I) wcre vescalagin J and its isomer castalagin 2 (Mayer et al 1967). These ellagitannins were the first Cglucosidic tannins known (C-glucosidic tannins have a carbon-carbon linkage between one aromatic residue and the carbon-1 of the glucose chain).…”