Synthesis and optical properties of the chloroquine enantiomers and their complexes with ferriprotoporphyrin IX in aqueous solution

Abstract

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.

Investigations on the Novel Antimalarial Ferroquine in Biomimetic Solutions Using Deep UV Resonance Raman Spectroscopy and Density Functional Theory

“…While decreasing the polarity of the solution, these two absorption lines merge together and become one, positioned at ∼333 nm, which is also blueshifted when enhancing the 1,4-dioxane content. According to literature, 128,129 the changes in band-shape are comparable to those occurring at high pH values for 4-aminoquinolines, where only the free base (FQ) is present.…”

3-[(E)-2-(5,7-Dichloro-8-hydroxyquinolin-2-yl)vinyl]-4-hydroxyphenyl acetate

“…-geometry diffractometer Absorption correction: none 13404 measured reflections 7118 independent reflections 5533 reflections with I > 2(I) R int = 0.024 Refinement R[F 2 > 2(F 2 )] = 0.043 wR(F 2 ) = 0.109 S = 1.06 7118 reflections 491 parameters 4 restraints H atoms treated by a mixture of independent and constrained refinement Á max = 0.54 e Å À3 Á min = À0.24 e Å À3 Table 1 Hydrogen-bond geometry (Å , ). of compounds of great interest from a synthetic, theoretical and practical point of view (O′Neill et al, 1998;Blauer et al, 1998;Egan et al, 2000). Styryl derivatives of chloroquinolines have recently attracted special attention due to their antiviral activity (Zouhiri et al, 2000).…”

TMSBr-Promoted Cascade Cyclization of ortho-Propynol Phenyl Azides for the Synthesis of 4-Bromo Quinolines and Its Applications

“…Until now, despite significant achievements having been made in the construction of functionalized quinolines [14,15,16,17,18,19,20,21,22], methods for the direct synthesis of 4-halo quinolines are still limited [23,24,25,26]. 4-halo quinolines have been widely used as key synthetic intermediates for the construction of various bioactive molecules or drugs [27,28,29]. Therefore, the development of an efficient and versatile strategy towards 4-halo quinolines is highly desirable, especially through a cascade cyclization, because of the merits of efficiency and atomic economy.…”