leucophyll

English

From leuco- +‎ -phyll.

leucophyll (uncountable)

(biochemistry) A colourless substance which was hypothesised to be a precursor compound of chlorophyll.
- 1963, E. M. Senchenkova, “V. N. Lyubimenko's Studies of Chlorophyll and their Modern Development”, in Israel Program for Scientific Translations, transl., Life Phenomena: A Historical Survey‎^[1], pages 134–135:
  Fischer's observations confirmed Lyubimenko's opinion that protochlorophyll represents an oxidised form of chlorophyll arising as a by-product during synthesis. Lyubimenko assumed that the first stage of chlorophyll synthesis is oxidation of the chlorophyll precursor, i.e., the hypothetical leucophyll. [...]
  The principal stages of initial chlorophyll biosynthesis are the condensation of pyrrole compounds with free alpha-positions, resulting in the formation of a more complex precursor of chlorophyll, i.e., a colorless leuco-compound corresponding to leucophyll. Oxidation of leucophyll leads to the formation of protochlorophyll.

The term does not refer to a specific chemical compound; it was used at a time when the biosynthesis of chlorophyll was not fully understood.