The unique series of C-1 acylated galloylhamameloses is extended by th
e discovery of oyl)-2',3,5-tri-O-galloyl-alpha-D-hamamelofuranose and
its 1-O-beta-anomer. They are accompanied by the parent 2',3,5-tri-O-g
alloyl-D-hamamelofuranose and the first pyranose analogue, shown to be
2',4-di-O-galloyl-D-hamamelopyranose. Assignment of H-1 NMR data for
the peracetates of hamamelitannin is revised on the basis of a NOESY e
xperiment. Structural examination of the proanthocyanidins present in
the bark of Hamamelis virginiana reveals the occurrence of the novel e
picatechin-(4 beta --> 8)-catechin-3-O-(4-hydroxy)benzoate, the uncomm
on prodelphinidins, epigallocatechin-(4 beta --> 8)-catechin, 3-O-gall
oyl epigallocatechin-(4 beta --> 8)-catechin and 3-O-galloyl epigalloc
atechin-(4 beta --> 8)-gallocatechin, together with the procyanidins,
3-O-galloyl epicatechin-(4 beta --> 8)-catechin and catechin-(4 alpha
--> 8)-catechin, and a tentatively characterized oligomer. The structu
res of these compounds were established by chemical and spectroscopic
methods.