TY - JOUR
T1 - Annonaceous acetogenins
T2 - Naturally occurring inhibitors of ATP synthesis and photosystem II in spinach chloroplasts
AU - Chàvez, D.
AU - Mata, R.
AU - Iglesias-Prieto, R.
AU - Lotina-Hennsen, B.
PY - 2001
Y1 - 2001
N2 - The effects of squamocin (1), bullatacin (2) and motrilin (3), 3 bis-tetrahydrofuran Annonaceous acetogenins, isolated from Annona purpurea (Annonaceae), were investigated on several photosynthetic activities in spinach thylakoids. The results indicated that compounds 1-3 significantly inhibited both ATP synthesis and uncoupled electron transport. In addition, they enhanced light-activated Mg2+-ATPase, and basal electron flow. Therefore, acetogenins 1-3 behave as uncouplers and Hill reaction inhibitors. Natural products 1-3 did not affect photosystem I (PSI) activity but they inhibited photosystem II (PSII) electron flow. The study of the partial PSII reactions from H2O to DCPIPox, H2O to SiMo and diphenylcarbazide to DCPIP established that the site of inhibition was at the oxygen-evolving complex (OEC). Chlorophyll a fluorescence measurements confirmed the behavior of the Annonaceous acetogenins as water-splitting enzyme inhibitors.
AB - The effects of squamocin (1), bullatacin (2) and motrilin (3), 3 bis-tetrahydrofuran Annonaceous acetogenins, isolated from Annona purpurea (Annonaceae), were investigated on several photosynthetic activities in spinach thylakoids. The results indicated that compounds 1-3 significantly inhibited both ATP synthesis and uncoupled electron transport. In addition, they enhanced light-activated Mg2+-ATPase, and basal electron flow. Therefore, acetogenins 1-3 behave as uncouplers and Hill reaction inhibitors. Natural products 1-3 did not affect photosystem I (PSI) activity but they inhibited photosystem II (PSII) electron flow. The study of the partial PSII reactions from H2O to DCPIPox, H2O to SiMo and diphenylcarbazide to DCPIP established that the site of inhibition was at the oxygen-evolving complex (OEC). Chlorophyll a fluorescence measurements confirmed the behavior of the Annonaceous acetogenins as water-splitting enzyme inhibitors.
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U2 - 10.1034/j.1399-3054.2001.1110219.x
DO - 10.1034/j.1399-3054.2001.1110219.x
M3 - Article
AN - SCOPUS:0034782698
SN - 0031-9317
VL - 111
SP - 262
EP - 268
JO - Physiologia Plantarum
JF - Physiologia Plantarum
IS - 2
ER -
