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Synthesis and optical properties of the chloroquine enantiomers and their complexes with ferriprotoporphyrin IX in aqueous solution
Author(s) -
Blauer Gideon,
Akkawi Muataz,
Fleischhacker Wilhelm,
Hiessböck Romana
Publication year - 1998
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/(sici)1520-636x(1998)10:7<556::aid-chir2>3.0.co;2-0
Subject(s) - chemistry , enantiomer , aqueous solution , titration , circular dichroism , chirality (physics) , stereochemistry , crystallography , inorganic chemistry , chiral symmetry breaking , physics , quantum mechanics , nambu–jona lasinio model , quark
Chloroquine (CQ) enantiomers were prepared by a novel synthesis starting from either (S)‐ or (R)‐pyroglutamic acid. Light‐absorption spectra of CQ and of complexes of ferriprotoporphyrin IX (FP) with CQ were measured in dilute aqueous solutions at pH 7.3 and 11.3. Spectrophotometric titrations at these pH values indicated a mole ratio of FP:CQ of 2:1 for the FP‐CQ aggregated complexes. Aqueous solutions of each of the CQ enantiomers (pH 7.3) and of their complexes with FP (pH 11.3) were investigated by circular dichroism (CD). At pH 11.3, the complexes of the two enantiomers showed CD‐band extrema of opposite sign at 409–410 nm. CD‐titrations at pH 11.3 confirmed a predominant mole ratio of FP:CQ of 2:1 in the complex. The possible origin of the optical activity of the FP‐CQ complexes is discussed. Chirality 10:556–563, 1998. © 1998 Wiley‐Liss, Inc.