[1] Natl Res Ctr, Ctr Excellence Adv Sci, Dept Chem Nat & Microbial Prod, Cairo 12622, Egypt
[2] Natl Res Ctr, Ctr Excellence Adv Sci, Dept Pharmaceut Res, Cairo 12622, Egypt
[3] Natl Res Ctr, Dept Polymers & Pigments, Cairo 12622, Egypt
[4] Stockholm Univ, Dept Analyt Chem, S-10691 Stockholm, Sweden
[5] Univ Illinois, Dept Phys, Urbana, IL 61801 USA