Isolation and Identification of Hydrangenol and Umbelliferone from Cultured Cells of Amacha (Hydrangea macrophylla Seringe var. Thunbergii Makino)

2-1-(1-Alkylamino)alkylidene]- 1,3-dicarbonyl compounds were synthesized as photosynthetic electron transport (PET) inhibitors because of their structural resemblance to the potent new PET inhibitors “cyanoacrylates”. Their functionalities were different from those of other classic photosystem II (PS II) inhibitors, and these compounds inhibited PET at the reducing side of PS II. In this paper, the synthetic approaches to these compounds are discussed.