THE GALLOTANNINS OF RHUS CORIARIA AND MANGIFERA INDICA

Abstract

From the leaves of both Syrian sumach (R. coriaria) and Egyptian mango (M. indica, Pyri) polyphenolic components of gallotannin properties were purely isolated. These two gallotannins, together with those isolated from the Indian mango panicles (M. indica, Rumani) as well as from tannic acid were thoroughly investigated.

Paper Chromatographie analysis, U. V. and I. R. measurements of the isolated gallotannins showed that they are rather identical as further confirmed by their acetyl and methyl derivatives.

Enzymic hydrolysis with purified galloyl esterase (tannase) led to both gallic acid and glucose whose amounts were estimated.

Thus, the structure of an octa– or nona–galloylated glucose may be assigned to Syrian sumach, Chinese and Indian mango gallotannins, whereas it is probable that the Egyptian mango gallotannin with 4–5 galloyl groups per glucose molecule might have a relatively different structure.