[1] Natl & Kapodistrian Univ Athens, Sch Sci, Dept Biol, Sect Cell Biol & Biophys, Athens 15701, Greece
[2] Natl Hellen Res Fdn, Inst Chem Biol, 48 Vassileos Constantinou Ave, Athens 11635, Greece
[3] Univ Patras, Dept Pharm, Lab Pharmacognosy & Chem Nat Prod, Rion 26504, Greece
[4] Hamburg Unit, European Mol Biol Lab, Notkestr 85, D-22607 Hamburg, Germany