13(2)-hydroxychlorophyll a, the first product of the reaction of chlorophyll-oxidase.

Chlorophyll-oxidase in barley thylakoids was activated by linolenic acid. The reaction products from endogenous chlorophylls were investigated by thin layer and high performance liquid chromatography. Within 2-10 min a new pigment was formed which migrated identically with authentic 13(2)-hydroxychlorophyll a (1a). After reaction with methanolic acid, the reaction product was identified as 13(2)-hydroxymethylpheophorbide (1b) by high performance thin layer and liquid chromatography.