Methods are described for the preparation and isolation of novel decapeptides of the formula: ##STR1## wherein each X is independently selected from the group comprising hydroxyl and hydrogen, wherein each R is independently selected from the group comprising hydrogen and methyl, from bioadhesive polyphenolic proteins which comprise: ##STR2## wherein n is a whole number from about 60 to about 100, wherein each X is independently selected from the group comprising hydroxyl and hydrogen, and wherein each R is independently selected from the group comprising hydrogen and methyl.Such decapeptides may be used to construct large polyphenolic molecules comprising from about 1 to about 1000 decapeptide repeating units and wherein the linking group is selected from the group comprising amino acid, oligopeptide and bifunctional spacer.