Many plant chemicals contain phenolic groups (as do hydroquinone,pyrogallol,pyrocatechol).I tried to extract the phenols from Broccoli by heating 200g Broccoli in 1% sodium carbonate (anh) solution at 100C for 15min with stirring.After filtering this Broccoli extract I added some Phenidone dissolved in isopropyl alcohol. PP-1 developer: Extract of 200g Broccoli Phenidone .................0.1g Sodium Carbonate 1% to 600ml. I checked that phenidone alone was not doing the developing by developing old APX 400 30m 20C ag 10s/min in PP-1 without the Broccoli extract.The negatives were very thin and flat. For the test, APX 400 at EI=200 was developed in PP-1 30m 20C ag10s/min. The negatives were slightly underdeveloped but otherwise good.The attachments show the full negative and a 0.2in square section. To see if there was any tanning I bleached the negs in 100g/L ferricyanide/bromide and fixed them.No relief image or tanning could be seen. This surprised me as I expected plant phenols to be like hydroquinone,pyrogallol, pyrocatechol and tan the negatives.The only explanation I can find is that the oxidation products of Broccoli phenols are not very stable and do not spread through the gelatin (Photographic Processing Chemistry, LFA Mason 1975 p172).Of course all this does rely on the assumption that it is the phenols from Broccoli that are involved in the developing. Thanks for comment.