Complex of a new racemic thiourea substrate: Spectrophotometric study and separation of atropisomers



  • Yahya Salma

    Laboratory of Applied Chemistry (LAC),
    Faculty of Science III, Lebanese University, P.O. Box 826, Tripoli

  • Hassan Zakaria

    Laboratory of Applied Chemistry (LAC),
    Faculty of Science III, Lebanese University, P.O. Box 826, Tripoli

  • Inas EL Hassan

    Laboratory of Applied Chemistry (LAC),
    Faculty of Science III, Lebanese University, P.O. Box 826, Tripoli

  • Mohammad Bouchekara

    Department of Chemistry,
    Faculty of Sciences and Technologies, University Mustapha Stanbouli of Mascara (29000),

  • Hanna El-Nakat

    Department of Chemistry,
    Faculty of Science, University of Balamand, P.O. Box 100, Tripoli,

  • Fawaz El Omar

    Laboratory of Applied Chemistry (LAC),
    Faculty of Science III, Lebanese University, P.O. Box 826, Tripoli

  • Ahmad Khodr Allouch

    Laboratory of Applied Chemistry (LAC),
    Faculty of Science III, Lebanese University, P.O. Box 826, Tripoli,



The activity of a chiral molecule can vary from one atropisomer to the other. In this study, the separation of racemic-N-(2-methylphenyl), N ™-(2-chlorophenyl) thiourea (H2L2), a hydrophobic heavy metal trap, has been studied using reversed-phase high-performance liquid chromatography (RP-HPLC) with hydroxypropyl-beta-cyclodextrin (HP-β-CD) as a complexing additive to the racemic mixture and hexane-isopropanol as a mobile phase. The stoichiometry and the overall association constant of the complex have been determined using the continuous variation (Job’s plot) method and the Scott’s method respectively.


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Author Biography

Ahmad Khodr Allouch, Laboratory of Applied Chemistry (LAC),
Faculty of Science III, Lebanese University, P.O. Box 826, Tripoli,

Department of chemistry,



. Doganoc D Z, Measurement of cadmium residues in muscle, liver and kidney of cattle slaughtered in Isfahan abattoir using grafite furnace atomic absorption spectrometry (GFAAS): a preliminary study, Food Addit Contam., 1996; 13(2): 237-241.

. Lutz E, Lind B, Herin P, Krakau I, Bui T-H and Vahter M, Methyl mercury and inorganic mercury in Swedish pregnant women and in cord blood: influence of fish consumption, J Trace Elem Med Biol., 1996; 10: 61-67.

. Gerhardsson L, Brune D, Nordberg GF and Wester PO, Distribution of cadmium, lead and zinc in lung, liver and kidney in long-term exposed smelter workers, Sci Total Environ., 1986; 50: 65-85.

. Casey CE, Robinson MF, Copper, manganese, zinc, nickel, cadmium and lead in human foetal tissues. Br. J. Nutr., 1978; 39 (3): 639-646.

. Fuerst DE and Jacobsen EN, Thiourea-Catalyzed Enantioselective Cyanosilylation of Ketones, J. Am. Chem. Soc., 2005; 127: 8964-8965.

. Tsogoeva SB, Hately MJ, Yalalov DA, Meindl K, Weckbecker C and Huthmacher K, Synthesis Antimicrobial and Anticancer Evaluation of 1-Aryl-5-(o-methoxyphenyl)-2-S-benzyl Isothiobiurets, Bioorg Med Chem., 2005; 13: 5680-5685.

. Hoashi Y, Yabuta T, Yuan P, Miyabe H and Takemoto Y, Enantioselective tandem Michael reaction to nitroalkene catalyzed by bifunctional thiourea: total synthesis of (???)-epibatidine, Tetrahedron, 2006; 62(2-3): 365-374.

. Joly GD and Jacobsen EN, Thiourea-Catalyzed Enantioselective Hydrophosphonylation of Imines: Practical Access to Enantiomerically Enriched α-Amino Phosphonic Acids, J. Am. Chem. Soc., 2004; 126: 4102-4103.

. Dalko PI and Moisan L, In the golden age of organocatalysis, Angew Chem Int., 2004; 43(39): 5138-5175.

. Szemán J, Ganzler K, Salgó A and Szejtli J, Effect of the degree of substitution of cyclodextrin derivatives on chiral separations by high-performance liquid chromatography and capillary electrophoresis, Journal of Chromatography A. 1996; 728 (1-2): 423-431.

. Weseloh G, Bartsch H and König WA, Separation of basic drugs by capillary electrophoresis using selectively modified cyclodextrins as chiral selectors, Journal of Microcolumn Separations, 1995; 7(4): 355-363.

. Arnaud S, Varesio E, Dreux M, and Veuthey JL, Binding constant dependency of amphetamines with various commercial methylated-beta-cyclodextrins, Electrophoresis, 1999; 20(13): 2670-2679.

. Szemán J, Roos N and Csabai K, Ruggedness of enantiomeric separation by capillary electrophoresis and high-performance liquid chromatography with methylated cyclodextrins as chiral selectors, Journal of Chromatography A. 1997; 763 (1): 139-147.

. Szejtli J, Introduction and General Overview of Cyclodextrin Chemistry, Chem Rev., 1998; 98(5): 1743-1754.

. Loftsson T and Brewster ME, Pharmaceutical applications of cyclodextrins. Drug solubilization and stabilization. J Pharm Sci., 1996; 85(10): 1017-1025.

. El Hassan I, Allouch A, Abou Dalle A, Tabcheh M, El-Nakat H and El Omar F, Spectrophotometric characterization of propranol-hydroxypropyl-β-cyclodextrin inclusion complex, Asian J Res Chem., 2012; 5(6): 718-721.

. Uekama K, Hirayama F and Irie T, Cyclodextrin drug carrier systems, Chem Rev., 1998; 98(5): 2045-2076.

. a) Szejtli J, Cyclodextrins and their inclusion complexes, Akademiai Kiadó, Budapest, 1982. b) Rajewski, R.A. and Stella, V.J., Pharmaceutical applications of cyclodextrins- In vivo drug delivery, J Pharm Sci., 1996; 85(11): 1142-1169.

. Irie T and Uekama K, Pharmaceutical applications of cyclodextrins, Toxicological issues and safety evaluation, J Pharm Sci., 1997; 86(2): 147-162.

. Bellec N, Lorcy D and Robert A, Towards Functionalised Quasi-planar Dithiadiazafulvalenes: Synthesis of Various Precursors, Synthesis, 1998; 10: 1442-1446.

. Job P, In Advanced Physicochemical Experiments, Ann. Chem. 16 (1936), p. 54, Oliner and Boyd, Edinburgh, UK, 2nd Edition, (1964).

. Scott RL, Some Comments on the Benesi-Hildebrand Equation. Recueil des Travaux Chimiques des Pays-Bas, Recl. Trav. Chim., 1956; 75: 787-789.

. Lamparczyk H and Zarzycki PK, Effect of temperature on separation of norgestrel enantiomers by high-performance liquid chromatography, J. Chromatogr., A, 1994; 668(2): 413-417.

. Tárkányi G, Quantitative approach for the screening of cyclodextrins by nuclear magnetic resonance spectroscopy in support of chiral separations in liquid chromatography and capillary electrophoresis enantioseparation of norgestrel with alpha-, beta- and gamma-cyclodextrins, J. Chromatogr., A, 2002; 961(2): 257-276.

. Butkus E, Martins JC and Berg U, 1H NMR study on the inclusion of bicyclo[3.3.1]nonanes in cyclodextrins, J. Incl. Phen., 1996; 26: 209-218.

. Grillo R, de Melo NF, Moraes CM, de Lima R, Menezes CM and Ferreira EI, Study of the interaction between hydroxymethylnitrofurazone and 2-hydroxypropyl-beta-cyclodextrin, J. Pharm. Biomed. Anal., 2008; 47: 295-302.

. Petracek FJ, Zekhmeister L, Determination of partion coefficients of carotenoids as a tool in pigment analysis, Anal. Chem., 1956; 28 (9): 1484-1485.

. Mashhood S, Santosh A and Upadhyay K, Complexation studies of pioglitazone hydrochloride and β-cyclodextrin: NMR. (1H, ROESY) spectroscopic study in solution, J. Incl. Phenom. Macrocycl. Chem., 2008; 62: 161-165.



How to Cite

Salma Y, Zakaria H, EL Hassan I, Bouchekara M, El-Nakat H, El Omar F, Allouch AK. . Int J of Pharm Chem [Internet]. 2018Apr.19 [cited 2020Jul.5];8(1):01-6. Available from:


Vol. 8 No. 1 (2018): Jan


Research Articles

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