Research Journal of Recent Sciences ______ ______________________________ ______ ____ ___ ISSN 2277 - 2502 Vol. 2 ( ISC - 2012 ), 55 - 60 (201 3 ) Res. J. Recent . Sci. International Science Congress Association 55 The Metal Complexes of 5 - [(benzyloxy) methyl] quinolin - 8 - ol (BeMQ) and 8 - quinolinols mixed Ligand: A New Transition metal Complexes with In - vitro Antifungal Activity Patel Ketan B., Patel Yogesh M. & Patel Raksha B. Government Science College, Department of Chemistry, Gandhinagar, Gujarat, INDIA Available online at: www.isca.in Received 31 st July 2012, revised 28 th December 2012, accepted 19 th January 201 3 Abstract 5 - Chloromethyl - 8 - quinolinol was condensed stoichiometr ically with various alcohols specially benzyl alcohol in presence of sodium carbonate. The resulting 5 - [(benzyloxy) methyl] quinolin - 8 - ol ( BeMQ ) was characterized by elemental analysis and spectral studies. The transition metal chelates viz. Cu 2+ , Ni 2+ , C o +2 , Mn 2+ and Zn 2+ of BeMQ and 8 - quinolinols were prepared and characterized by mixed ligand complexes(L:M:L) ratio, elemental analysis, IR, reflectance spectral studies, magnetic properties and conductivities measurements. The antifungal activity of BeMQ and its metal chelates was investigated against various fungi. The metal complexes exhibit good activity against fungal strains compared with parental compounds. Keywords: Transition metal complexes , 8 - quinolinols, spectral studies, magnetic moment and I n - vitro antifungal activity . Introduction Transition metals have varying utility and interesting chemistry. Coordination compounds are important due to their role in biological and chemical systems in various ways. It has been observed that metal comple xes with appropriate ligands are chemically more significant and specific than the metal ions and original 1 - 2 . It is well known that mixed ligand ternary complexes of some metals play an important role in the activation of enzymes 3 . It is studied that mixe d ligand complexes are biologically active against pathogenic microorganisms 4 - 5 ; further, metal complexes, which include 8 - hydroxyquinoline as a primary ligand, exhibit biological activity 6 . One of the derivative say 5 - chloromethyl 8 - Quinolinol (CMQ) can b e synthesize easily and studied extensively for number of derivatives 7 . CMQ precursor for the synthesis of many coordination polymers, biological active compounds as well as ion - exchanger 8 - 10 . There has been a tremendous growth of drugs from quinoline fami ly, which began with the discovery of nalidixic acid (Hnal) some 40 years ago. Since then, the exponential growth of this family has produced more than ten thousand analogues 11 . The complexation of metallic elements with biologically inactive compounds ren ders them active; and in case the compounds are already active, it makes them more active. The mechanism involved in enhancing this biological activity upon complexation is still needed to be further investigated 12 - 15 . As a part of our ongoing work 16 - 18 o n mixed ligand complexes, in this paper we reporting the newly s ynthesized complexes of Cu (II) , Ni (II), Co (III), Mn (II), and Zn(II) ions with 5 - ( benzyloxy methyl) - 8 - Quinolinol as primary and heterocyclic bases, viz., Quinoline (Q), 8 - hydroxyquinoline (8 - HQ) as secondary ligand. Their antifungal activities investigated to perform primary selection of these complexes as the therapeutic agents. Material and Methods Reagent and solvents: All the chemicals and reagents used for the preparation of ligands and complexes were commercial products (E. Merck Ltd, India) and used without further purification. Acetic acid and EDTA were purchased from Sigma Chemical Co., India. The organic solvents were purified by recommended method 19 . Physical measurements : The metal content of the complexes were determined by the EDTA titration technique 20 after treating them with mixture of HClO 4 , H 2 SO 4 and HNO 3 (1:1.5:2.5). Elemental analysis was carried out using Perkin Elmer, USA 2400 - II CHN analyzer. The magnetic moments we re obtaied by the Gouy’s ethod usig erury tetrathiocyanatocobaltate (II) as a alibrat χ g =16.4410 - 6 c.g.s. units at 20 o C). Diamagnetic corrections were made using Pasal’s ostat 21 . The IR spectra were recorded on a FT - IR Nicolet 400D Spectrophotometer using KBr pellets. NMR spectra were recorded on a model Bruker Avance (40 0MHz). A simultaneous TG/DTG had been obtained by a model 5000/2960 SDT, TA Instruments, USA at heating rate of 10 o C min - 1 under N 2 atmosphere. The conductivities of the metal complexes in DMF were measured using conductivity Bridge 305 Systronics and a c alibrated conductivity cell at room temperature. Preparation of ligand: Synthesis of 5 - [(benzyloxy) methyl] quinolin - 8 - ol (BeMQ) : To a suspension of 2.3 gm. (0.01 mole) Research Journal of Recent Sciences ______ _ _ _______________________________ ______________ _ ________ ISSN 2277 - 2502 Vol. 2 ( ISC - 2012 ), 55 - 60 (201 3 ) Res. J. Recent. Sci . International Science Congress Association 56 of 5 - chloromethyl - 8 - quinolinol (CMQ), benzyl a s lcohol (3 times.) and 0.84 gm. (0.01 mo le) of sodium carbonate (NaHCO 3 ) added. The mixture was warmed on the steam bath with occasional shaking until most of the alcohol had been distilled. The pale yellow solid was dissolved in water and made basic with 5 % ammonium hydroxide. The white solid was collected on a filter and dried to give 1.50 gm. (60% yield), having m.p. - 82C. (Uncorrected). FT - IR (KBr, cm - 1 : υ - OH,) 3375 - 3385, υ - C - N) 1285 - 1298, elemental analysis found (%) : C, 76.81; H, 5.66; C 17 H 15 NO 2 (265) requires (%): C, 76.96, H, 5.70.Scheme represented in below given . Preparation of Metal Complexes: Formation of Cu 2+ Complexes: A water solution (1 00 ml) of cupric nitrate hexahydrate (10 mmol, 2.41 g) was added to dimethyl formamide solution (100 ml) of ligand (BeMQ) (10 mmol, 2.77 g), followed by addition of 8 - hydroxyquinoline (10 mmol, 3.05 g) in ethanol; the pH was adjusted to 4.5 - 6.0 with dilute NaOH solution. The resulting solution was refluxed for 7 h and then heated over a steam bath to evaporate up to half of the volume. The reaction mixture was kept overnight at room temperature. The obtained product was washed with ether and dried over vacu um desiccators. The yield of a purified complex was 67%. The reaction scheme is shown in figure : 2 and physical data are shown in table 1. IR Spectra and IR data are shown in figure : 3 and table 2 respectively. Fig ure - 1 Fig ure - 2 Synthesis of Cu+ 2 co mplexes Research Journal of Recent Sciences ______ _ _ _______________________________ ______________ _ ________ ISSN 2277 - 2502 Vol. 2 ( ISC - 2012 ), 55 - 60 (201 3 ) Res. J. Recent. Sci . International Science Congress Association 57 Formation of Ni 2+ complex : Ni +2 complex was synthesized by same method used for Cu +2 complexes. A dull greenish colored crystalline product was obtained. The yield of a purified complex was 65%. Formation of Co 2+ complex : Co +2 complex was synthes ized by same method used for Cu +2 complexes. A light brown colored crystalline product was obtained. The yield of a purified complex was 61%. Formation of Mn 2+ Complex : Mn +2 complex was synthesized by same method used for Cu +2 complexes. A light pink col ored crystalline product was obtained. The yield of complex was 73%. Formation of Zn 2+ Complex : Zn +2 complex was synthesized by same method used for Cu +2 complexes. A pale yellow colored powder product was obtained. The obtained product was washed with e ther and dried over vacuum desiccators. The yield was 64%. Table - 1 Characterization of metal complexes of Ligand (BeMQ+8 - HQ+M) Fig ure - 3 IR Spectra of Cu (II) Complex. Table - 2 IR Sp ectral data of complex Metal complex Frequencies cm - 1 (  ) 8 - HQ Aromatic C - N CH 2 OH (BeMQ) - Cu(II) - 8HQ 1638 1690 1509 1390 1598 1461 3108 1269 2840 2975 1469 3500 - 2600 broad Metal complexes Molecular formula M. wt gm/mole Yield % % Metal analysis Elemental analysis Cal. Found % C % H % N Cal. Found Cal. Found Cal. Found (BeMQ) 8HQCu +2 C 26 H 24 N 2 O 5 Cu +2 508.03 67 12.51 12.45 61.47 61.45 4.76 4.75 5.51 5.49 (BeMQ) 8HQNi +2 C 26 H 24 N 2 O 5 Ni +2 503.17 65 11.66 11.65 62.06 62.03 4.81 4.78 5.57 5.51 (BeMQ) 8HQMn +2 C 26 H 24 N 2 O 5 Mn +2 499.42 73 11.00 10.96 62 .53 62.49 4.84 4.80 5.61 5.55 (BeMQ) 8HQCo +2 C 26 H 24 N 2 O 5 Co +2 503.41 61 11.71 11.65 62.03 62.00 4.81 4.77 5.56 5.51 (BeMQ) 8HQZn +2 C 26 H 24 N 2 O 5 Zn +2 509.89 64 12.83 12.79 61.24 61.19 4.74 4.69 5.49 5.45 Research Journal of Recent Sciences ______ _ _ _______________________________ ______________ _ ________ ISSN 2277 - 2502 Vol. 2 ( ISC - 2012 ), 55 - 60 (201 3 ) Res. J. Recent. Sci . International Science Congress Association 58 Antifungal activity: The antifungal activity of the standard fungicide (Cli oquinol), ligand and complexes were tested for their effect on the growth of microbial cultures and studied for their interaction with Penicillium Expansum, Botrydepladia Thiobromine, Nigras Pora Sp Aspergillus Niger and Trichothesium Sp. usig Czapek’s ag armedium having the composition, glucose 20 g, starch 20 g, agar - agar 20 g and distilled water 1000 ml. To this medium was added requisite amount of the compounds after being dissolved in methanol so as to get the certain concentrations (50, 100 and 200 pp m). The medium then was poured into petri plates and the spores of fungi were placed on the medium with the help of ioulu’s eedle. These petri plates were wrapped i polythene bags containing a few drops of alcohol and were pl aced in an incubator at 30 C. The controls were also run and three replicates were used in each case. The linear growth of the fungus was recorded by measuring the diameter of the fungal colony after 96 h and the percentage inhibition was calculated by the equation: % Inhibition D (C – T / C) 100 Where C and T are the diameters of the fungal colony in the control and the test plates, respectively. 22 % Activity Index = D Zone of inhibition by test compound x 100 /Zone of inhibition by standard. Resutls are shown in Below given table 3 . Results and Discussion The toxic effect of all the complexes on fungi is shown in table 3. The results give the following conclusions. All the complexes are toxic more or less to fungi. In all complexes the Cu - complexes have much toxicity. This is exp ected because the copper salts are mostly used as fungicides. Most of the complexes inhibit the growth of the above organisms which cause decease in many plants. Cu +2 metal complexes are more toxic than others and the toxicity is in order of Cu +2  Zn +2  Co +2  Ni +2  Mn +2 . IR spectra: The important infrared spectral bands and their assignments for the synthesized ligands and complexes were recorded as KBr discs and are presented in table 2. The IR data of the free ligands and its metal complexes were ca rried out within the IR range 4000 – 400 cm - 1 . A broad band was observed in the region between 3460 and 3431 cm − 1 due to asymmetric and symmetric O – H stretching modes and a band in the range 1600 – 1585cm − 1 due to H – O – H bending vibrations indicating the prese nce of coordinated water molecules further confirmed by thermal studies. The ν (CO) band is observed at ∼ 1120 cm − 1 . The position of this band undergoes variation depending on metal complex under study 23 . A strong ν (CO) band observed in the range between 110 6 and 1105 cm − 1 indicates the presence of oxine moiety in the complexes coordinated through its nitrogen and oxygen atoms as uninegative bidentate ligand 24 . In the investigated heterochelates , the band observed in the region 3420 - 3500, 1290 - 1305, 865 - 875 a nd 714 - 716 cm - 1 are attributed to – OH stretching, bending, rocking and wagging vibrations, respectively due to the presence of water molecules 25 . The evidence of complexes formation clear by appearance of new bands at 416 – 430 and 508 – 517 cm −1 , which are as signed to ν (M – N) and ν (M – O), respectively 26,27 . Reflectance spectra, magnetic measurements and conductivity: In order to shed some light on the geometrical structure of the complexes, the reflectance spectra of the complexes were recorded in the solid ph ase at room temperature. The reflectance spectra of the Mn(II) complex shows absorption bands at ~16202, ~17985 and ~22102 cm – 1 assignable to 6 A 1g → 4 T 1g , 6 A 1g → 4 T 2g and 6 A 1g → 4 A 1g , 4 E g transitions, respectively, in an octahedral environment around the Mn (II ) ion. The magnetic moment value of the Mn (II) complex is 5.55 B.M. due to a high - spin d 5 - system with an octahedral geometry. 28 For the Co (II) complex , the reflectance spectra exhibits the bands of medium intensity at ~8748 ~18979, and ~24120 cm – 1 , which may reasonably be assigned to 4 T 1g F → 4 T 2g (F), 4 T 1g F → 4 A 2g (F) and 4 T 1g F → 4 T 2g (P) transitions, respectively, of an octahedral geometry around the metal ion 29 and the magnetic moment value is observed to be of 4.65 B.M. The electronic spectra of the Ni (II) complex exhibits absorption b ands at ~13254 and ~22570 cm – 1 assignable to 3 A 2g (F) → 3 T 1g (F) and 3 A 2g F → 3 T 1g (P) transitions respectively, in an octahedral geometry. The value of the magnetic moment (2.97 B.M.) may be taken as additional evidence for their octahedral structure 30 - 33 . T he Cu (II) complex display a broad band at ~15715 cm – 1 due to the 2 B 1g → 2 A 1g transition and the magnetic moment value is 1.92 B.M., which is close to spin - only value (1.93 B.M.) expected for an unpaired electron, which offers the possibility of an octahedra l geometry 34 . Table - 3 Antifungal activity of ligand (BeMQ) and their metal complexes Sample Zone of inhibition at 1000 ppm (%) Penicillium expansum Botrydepladia thiobromine Nigras pora Sp. Trichothesium Sp. A. niger Clioquinol 64 63 72 67 62 8 - HQ 59 61 69 55 57 (BeMQ) 66 63 69 57 53 (BeMQ)8HQCu +2 82 83 79 81 85 (BeMQ)8HQMn +2 55 56 55 59 55 (BeMQ)8HQCo +2 69 69 65 66 69 (BeMQ)8HQZn +2 81 80 71 71 73 (BeMQ)8HQNi +2 60 63 60 60 59 Research Journal of Recent Sciences ______ _ _ _______________________________ ______________ _ ________ ISSN 2277 - 2502 Vol. 2 ( ISC - 2012 ), 55 - 60 (201 3 ) Res. J. Recent. Sci . International Science Congress Association 59 Table - 4 Experimental data of magnetic moment and conductivity of m etal complexes Metal complexes  g  10 - 6 (cgs)  m  10 - 6 (cgs) Magnetic moment  eff (BM)  eff = BM  eff (BM) Expected (HL - 9) 8HQMn +2 20.50 12693 5.55 5.91 5.2 - 6.0 7.98 (HL - 9) 8HQCo +2 14.30 8910 4.65 3.87 4. 4 - 5.2 2.20 (HL - 9) 8HQNi +2 5.83 3634 2.97 2.82 2.9 - 3.4 11.02 (HL - 9) 8HQCu +2 2.42 1519 1.92 1.93 1.7 - 2.2 7.80 (HL - 9) 8HQZn +2 - - - - D(*) 9.20 The conductivity of 0.001 M each solution of each complex was measured twice or thrice and the constant value observed was used in further calculations. From the measured conductivity, specific and molar conductivities were calculated using following formula: Sp. Conductivity = cell constant X conductivity Molar conductivity = Sp. Conductivity X Where, M is the molarity of the solution. Results are tabulated in table : 4. Conclusion The complexes were obtained as colored powdered materials and were characterized using IR spectra, electronic spectra, and magnetic measurements. Th e compounds were insoluble in ethanol, methanol, DMF, acetone, ether, hexane, chloroform, THF, and dichloromethane, and soluble in DMSO. The elemental analyses were in good agreement with the complexes. From the In - vitro antifungal activity data, it is obs erved that the complexes exhibit higher activity than the free ligands, metal salt, and the control (DMSO). The increase in antifungal activity of the complexes may be due to the metal chelation. From comparative analysis as shown in Table 3, it is observe d that all the metal complexes are more potent therapeutic than the ligand. The zone of inhibition was measured (in %). 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