The main allergens are 3-methyl-2-butenyl caffeate and phenylethyl caffeate. Benzyl salicylate and benzyl cinnamate are less frequent sensitizers. Propolis is found in a number of "natural ...

and there is of the caffeate of coffee and tannin combined with alkali and caffeine, about 5 per cent, and 13 per cent of fat, sugar, and gum ; the rest is lignin, albumen, and water. The process ...