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.
