1 The Journal of the Argentine Chemical Society Vol. 97 N 1, (2009) (Special issue dedicated to Professor E. Baran) 80 Journal of the Argentine Chemical Society RESEARCH OF NEW MIXED-CHELATE COPPER COMPLEXES WITH QUINOXALINE N 1,N 4 -DIOXIDE DERIVATIVES AND ALANINE AS LIGANDS, POTENTIAL ANTIMYCOBACTERIAL AGENTS M. Belén Tarallo 1, A. J. Costa-Filho 2, Ernanni D. Vieira 2, Antonio Monge 3, Clarice Q. Leite 4, Fernando R. Pavan 4, Graciela Borthagaray 5, Dinorah Gambino 1 +, and María H. Torre 1 * 1 Cátedra de Química Inorgánica and 5 Cátedra de Microbiología Facultad de Química, Universidad de la República, Gral Flores 2124, C. C. 1157, Montevideo, Uruguay. 2 Instituto de Física de São Carlos, Universidade de São Paulo, C.P. 369, 13560, São Carlos, Brasil. 3 CIFA, Universidad de Navarra, Pamplona, España. 4 Faculdade de Ciencias Farmacêuticas Unesp- C.P. 582, Araquara(SP),Brazil. Received November11, In final form March 11, The authors would like to thank Dr. E. J. Baran for the important support that he gave during several years for the consolidation of the bioinorganic chemistry group in the Faculty of Chemistry (UDELAR), Montevideo, Uruguay. Abstract Three new mixed-chelate copper complexes with 3-aminoquinoxaline-2-carbonitrile N 1,N 4 - dioxide derivatives and alanine as ligands were synthesized in solid state. The spectroscopic J. Argent. Chem. Soc., 2009, 97(1), 80-89
2 81 M. B. Tarallo et al. characterization (FTIR, EPR, UV-Vis) showed that copper coordinated through the amine and the N-oxide groups of the quinoxaline derivatives and the amine and carboxylate moieties from alanine forming a dimeric species. The tree complexes showed in vitro activity against M. tuberculosis H 37 Rv (ATCC 27294) similar to that of ethambutol while they are inactive against E. coli and S. aureus. Keywords: antimycobacterial agents, copper complexes, quinoxaline derivatives. Resumen Tres nuevos complejos mixtos de cobre con derivados de 3-aminoquinoxalina-2- carbonitrilo N 1,N 4 -dióxido y alanina como ligandos fueron sintetizados en estado sólido. La caracterización espectroscópica (FTIR, EPR, UV-Vis) mostró que el Cu coordina con el grupo amino y el N-óxido del derivado quinoxalínico y con el amino y el carboxilato de la alanina formando especies diméricas. Los tres complejos mostraron actividad frente al M. tuberculosis H 37 Rv (ATCC 27294) similar a la del etambutol, mientras que fueron inactivos frente a E. coli y S. aureus. Palabras clave: agentes antimicobacterianos, complejos de Cu, derivados quinoxalínicos. Introduction Tuberculosis is an infectious disease caused by mycobacteria, mainly Mycobacterium tuberculosis. It can lead to serious complications and even death, especially if it is accompanied by other bacterial infections and if the patients have their immune systems compromised by immunosuppressive drugs, abuse substances, or HIV/AIDS, among others . The World Health Organization (WHO) estimates that about 30 million people will be infected in the next 20 years, not only in the third world but also in the developed countries . In view of the importance of this disease and the emergence of multi-drug resistant strains, the investigation and development of new drugs is a leading area of research. The study of quinoxaline derivatives has become of much interest in recent years due to their antibacterial, antiviral, anticancer, antifungal, antihelminthes and insecticidal activities . In particular, the di-n-oxide derivatives of quinoxaline show a dramatically increase of the diversity of biological properties. For example, some of these organic derivatives have shown hypoxia-selective citotoxicity and they could be potentially useful for the treatment of solid tumors. Besides, some derivatives have presented excellent M. tuberculosis growth inhibition values, leading generally the lack of the two N-oxide groups to the loss of the antimycobacterial activity [3-6]. Although excellent in vitro biological results have been obtained with some 3-amino-2-carbonitrilequinoxaline N 1,N 4 -dioxide derivatives, they were not useful for therapy owing to too short in vivo half lives and low solubility in physiological media [7-10]. As an effort to improve bioavailability and pharmacological and toxicological properties of quinoxaline N 1,N 4 -dioxide derivatives, we have focused our current research on the synthesis, characterization and biological evaluation of a large amount of metal complexes with this family of organic compounds [11-15]. These studies lead to several complexes with higher pharmacological activity than the free ligands, especially iron complexes bearing anti-mycobacterium tuberculosis activity. Nevertheless, in many cases the lipophilicity and solubility of the developed complexes still remained non adequate for therapeutically purposes. Therefore we decided to take advantage of a well known strategy in the search for more active metal-based drugs that involves the incorporation of a second ligand in the metal coordination sphere, like an aminoacid, with the aim of obtaining different levels of hydrophobicity . Taking into account these antecedents and
3 Research of new mixed-chelate copper complexes with quinoxaline 82 trying to know more about the effect of metal coordination on the bioactivity of selected 3- aminoquinoxaline-2-carbonitrile N 1,N 4 -dioxide derivatives, in this work we present the synthesis in solid state and the analytical and spectroscopic characterization of a new series of mixed-chelate Cu(II) complexes with different non- and mono-substituted 3-aminoquinoxaline-2-carbonitrile N 1,N 4 -dioxide derivatives (Figure 1) and alanine (ala) as ligands. Besides, their antibacterial activities against E. coli, S. aureus and M. tuberculosis are reported. Experimental Materials and methods All starting materials were commercially available research-grade chemicals and were used without further purification. The quinoxaline derivatives (see Figure 1) were synthesized in CIFA, Navarra University, Pamplona (Spain) by Dr. Monge s group. R1 O - N + CN Ligand R1 R2 L1 H H R2 N + O - NH 2 L2 Cl H L3 F H Figure 1. 3-aminoquinoxaline-2-carbonitrile N 1,N 4 -dioxides used as ligands. Synthesis of the complexes The complexes were synthesized through a solid state technique  by mixing CuCO 3 Cu(OH) 2 (11 mg), alanine (9 mg) and L (20.0 mg of L1 or 23.5 mg of L2 or 22.0 mg of L3), adding some drops of water and heating the mixture at 80 ºC during 6 h. In all the cases red complexes were formed. The yields (%) were 95.5, 77.6 and 90.0, respectively. The stoichiometries obtained were [Cu(L-H)(ala-H)] for the three complexes where L-H and ala-h are the deprotonated ligands. The results of the elemental analysis (%) obtained with a Carlo Erba EA 1108 analyzer were: for [Cu(L1-H)(ala-H)] (Code CuL1ala) C 12 H 12 N 5 O 4 Cu Found/ Calc.: C, 40.48/ 40.97; N, 19.74/ 19.91; H, 3.05/ 3.15; for [Cu(L2-H)(ala-H)] (Code CuL2ala) C 12 H 11 N 5 O 4 ClCu Found/ Calc.: C, 36.89/ 37.06; N, 17.58/ 18.02; H, 3.02/2.83 and for [Cu(L3-H)(ala-H)] (Code CuL3ala) C 12 H 11 N 5 O 4 FCu Found/ Calc.: C, 38.72/ 38,76; N, 18.61/ 18.84; H, 3.15/ The electronic spectra of the three complexes showed in DMF and ethanol a broad band near 500 and a shoulder near 570 nm, in agreement with the red-purple colour of the solutions.
4 83 M. B. Tarallo et al. Spectroscopic measurements IR spectra, in the range between 4000 and 400 cm -1, were recorded on a Bomem M 102 FTIR spectrophotometer using the KBr pellet technique. Electronic spectra of the complexes were registered on a Shimadzu UV-1603 spectrophotometer. Electron Paramagnetic Resonance (EPR) experiments were carried out in a Bruker ELEXSYS E580 spectrometer operating at 9.5 GHz. EPR spectra of solid- (polycrystalline) and in DMSO solution samples of the three compounds were measured at 30 K using experimental parameters such that signal saturation and distortion was avoided. Temperature was controlled by means of an ITC503 Oxford cryostat system. Microbiological assays Agar dilution tests were used to determine the minimal concentration of the antimicrobial agent required to inhibit or kill the microorganisms (MIC). Every step in the procedure for performing the agar dilution susceptibility test  was based on recommendations from the National Committee for Clinical Laboratory Standards . A suspension in sterile physiological serum of the complexes was incorporated in 20 ml of Mueller-Hinton agar and poured into Petri dishes. The ph of each batch of medium was in the range 7.2 to 7.4. The dilution scheme for each antimicrobial agent covered a μg of complex/ml range. The same process was carried out with a water dilution of CuSO 4 5H 2 O. The standard strains used were E. coli ATCC and S. aureus ATCC In each case, a suspension of about 10 4 colony-forming units / drop (CFU/drop) in Trypticase soy broth was prepared and diluted (1:20) in physiological serum. One drop of this suspension was inoculated on the agar surface containing the indicated dilutions of the antimicrobial agent, and on the control dish containing no antimicrobial agent. All tests and inoculations on each dish were run in duplicate. The anti-m. tuberculosis activities of the compounds were determined using the MABA as analytical method . Stock solutions of copper complexes were prepared in dimethyl sulfoxide and diluted in broth medium Middlebrook 7H9 (Difco), supplemented with oleic acid, albumin, dextrose, and catalase (OADC enrichment - BBL/Becton-Dikinson, Sparks, MD, USA), to obtain final compounds concentration ranges of 0.15 to 50 μg/ml. Isoniazid was solubilized with distilled water according to the manufacturers recommendations (Difco laboratories, Detroit, MI, USA) and used as standard drug. M. tuberculosis H 37 Rv ATCC was grown for 7 to 10 days in Middlebrook 7H9 supplemented with OADC added of 0.05 % Tween 80 to avoid clumps. Suspensions were prepared and their turbidities matched to a McFarland no. 1 (turbidity standard). After further dilution of 1:25 in Middlebrook 7H9 supplemented with OADC, the inoculum was added to each well of the 96 well microtiter plate (Falcon 3072; Becton Dickinson, Lincoln Park, NJ) together with the compounds. Samples were set up in triplicate. Cultures were incubated for 7 days at 37 o C, and Alamar Blue was added for the reading. The minimum inhibitory concentration (MIC) was defined as the lowest concentration resulting in 90 % inhibition of growth of M. tuberculosis determined by measuring the fluorescence (excitation/emission of 530/590 nm filters respectively) in a SPECTRAfluor Plus (Tecan) instrument. For standard test, the MIC value of isoniazid was determined each time. The acceptable MIC of isoniazid ranged from to 0.05 µg/ml .
5 Research of new mixed-chelate copper complexes with quinoxaline 84 Results and discussion Infrared spectra The IR spectra of the complexes were compared with those of the free ligands and of previously reported complexes [11-15]  . The results obtained are shown in Table 1. For the sake of clarity data of alanine IR spectrum were also presented in Table 1. Figure 2 shows as an example the IR spectra of L3, ala and the corresponding complex. All the complexes showed a similar spectral pattern. After the coordination the ligand s bands corresponding to ν as (NH 2 ) (in the cm -1 range) and ν s (NH 2 ) (in the cm - 1 range) of the amino group of quinoxaline derivatives disappeared and only one band was observed (in the cm -1 range). This is in accordance with the presence of a secondary amine formed by deprotonation of the primary amine as a consequence of the coordination with copper ion, as previously observed for vanadyl and copper complexes with this family of ligands. This behavior was also observed in metal chelates with aromatic ligands involving the amino group in ortho position to the N-oxide [11-15] . Table 1. Main bands and proposed assignments (cm -1 ) of copper complexes IR spectra and free ligands Compound ν as (NH 2 ) ν s (NH 2 ) ν(nh) ν(n-o) ν as (C N) δ(nh 3 + ) ν as (COO - ) ν s (COO - ) L CuL1ala -* -* nd 1395 L CuL2ala -* -* nd 1389 L CuL3ala -* -* nd 1397 ala *:Only the symmetric and antisymmetric stretchings of the quinoxaline ligands were included ; nd = not determined. Furthermore, the strong ν(n O) band for the free ligands ( cm -1 ) shifted in the complexes being overlapped with other bands, showing the coordination through this group. The ν(c N) ( cm -1 ) suffered only minor changes upon complexation in agreement with the fact that this group did not coordinate to copper ion. Moreover, data show the copper coordination through the alanine ligand in the three complexes. The free aminoacid exists as zwitterion in the crystalline state. This is demonstrated by the existence of the δ(nh 3 + ) band at 2113 cm -1. This band disappeared in the complexes showing the copper coordination through the amine terminal group of the alanine ligand. Besides, two vibrations for the COO- moiety (ν as (COO - ) at 1590 cm -1 and ν s (COO - ) at 1413 cm -1 ) are observed in the zwitterion. After coordination a lowering of the frequency of one of these bands and the
6 85 M. B. Tarallo et al. increase of the other are expected. In our complexes, ν s (COO - ) shifted to low frequencies ( cm -1 ). This behavior is similar to that of [Cu(ala) 2 ] that presents one band at 1400 cm -1 . The ν as (COO - ) was overlapped by quinoxaline bands and consequently could not be assigned. Besides, the strong band assigned as ν as (NH 2 ) in the alanine spectrum (3082 cm -1 ) shifted to higher wavelengths in the mixed-chelate complexes (around 3244 cm -1 ). This behavior is in agreement with previously reported data for [Cu(ala) 2 ] (3245 cm -1 ) [23-24]. 60 CuL3al Transmitance L3 ala Wavenumber (cm -1 ) CuL3ala 60 L3 ala Transmitance Wavenumber (cm -1 ) Figure 2. IR spectra of ligands (quinoxaline derivative and ala) and the corresponding complex CuL3ala EPR spectra Polycrystalline samples of the three complexes presented EPR spectra (Figure 3) characteristic of coupled pairs with a distorted resonance around 330 mt (g~2) and a half-field
7 Research of new mixed-chelate copper complexes with quinoxaline 86 transition around 165 mt (inset in Figure 3A). This half-field line is only observed in S=1 spin systems and is the result of the forbidden ΔM S =±2 transition . Hence, in the solid state, the complexes exist as dimmers containing exchange-coupled pairs of S=1/2 Cu(II) ions as previously observed for other copper compounds in the same conditions [12, 13, 26]. Upon dilution in DMSO, the spectra change to the usual EPR spectra of Cu(II) ions (Figure 3B) showing features assigned to the hyperfine interaction between the S=1/2 electron spin and the I=3/2 nuclear spin [27, 28]. The frozen-solution spectra are characterized by the following parameters: g // =2.2513, A // =17.5 mt, g = Our EPR results thus show that, in solution, the complexes are in a tetragonally monomeric form with ground state d x2-y2. The EPR spectrum at room temperature shows the same behavior (data not shown). (A) (B) CuL1ala CuL2ala CuL3ala Magnetic field (mt) Magnetic field (mt) Figure 3. Low-temperature (30 K) EPR spectra from: (A) polycrystalline samples and (B) DMSO solutions of CuL1ala, CuL2ala, and CuL3ala. The inset shows the half-field transition discussed in the text. Microbiological assays The minimum inhibitory concentration (MIC) values of Cu complexes against E.coli (ATCC 25922), S. aureus (ATCC 29213) and M. tuberculosis H 37 Rv (ATCC 27294) are shown in Table 2. The three complexes were inactive against E.coli and S. aureus, while they were active against M. tuberculosis. The MIC values of all the complexes are of the same order than that of ethambutol (MIC = 5.62 μg/ml), an antimycobacterial agent in clinical use. Nevertheless, they are less active than other drugs like p-amino salicylic (PAS) (MIC = 1.25 μg/ml) and isoniazid (MIC = μg/mL). Taking into account the analytical and spectroscopic results and our antecedents with Cu complexes of this kind of ligands, a possible structure for the complexes is proposed in Figure 4. This proposal is supported by our previous studies where homoleptic copper-quinoxaline complexes
8 87 M. B. Tarallo et al. [12-13] showed the presence of bridges that permitted to explain the dimeric molecules shown by EPR. Besides, a similar IR pattern was observed by the compounds presented in this work. Table 2. MIC values (μg/ml) of Cu complexes against E. coli, S. aureus and M. tuberculosis Compound E. coli S. aureus M. tuberculosis CuL1ala > 400 > CuL2ala > 400 > CuL3ala >400 > Figure 4. Scheme of the proposed structure for the copper complexes (R=-CH 3 ). Conclusions Three new mixed-chelate copper complexes with 3-aminoquinoxaline-2-carbonitrile N 1,N 4 - dioxide derivatives as ligands were synthesized in solid state. The spectroscopic characterization showed that copper coordinated with both ligands: quinoxaline derivative and alanine, forming dimeric species in the solid state. The three complexes showed in vitro activity against M. tuberculosis H37Rv (ATCC 27294) similar to that of ethambutol. These results have encouraged us to continue this research further. Acknowledgements. This work was supported by PEDECIBA Química (Uruguayan organization).the authors would like to thank Carolina Buzó for her contribution in the microbiological tests.
9 Research of new mixed-chelate copper complexes with quinoxaline 88 References  P. G. Smith, A. R. Moss, Epidemiology of Tuberculosis. in: Bloom B. R. (Ed). Tuberculosis, Pathogenesis, Protection and Control, ASM Press, Washington, 1994, pp  S. A. Khan, K. Saleem, Z. Khan, Eur. J. Med. Chem. 2007, 42,103.  Y. Sainz, M.E. Montoya, F.J. Martínez-Crespo, M.A. Ortega, A. L. Ceráin, A. Monge, Arzneim -Forsch Drug Res. 1999, 1, 55.  M. E. Montoya, Y. Sainz, M.A. Ortega, A. L. Ceráin, A. Monge, Il Farmaco 1998, 53, 570.  B. Zarranz, A. Jaso, I. Aldana, A. Monge, Bioorg. Med. Chem. 2003, 11, 21.  A. Jaso, B. Zarranz, I. Aldana, A. Monge, Eur. J. Med. Chem. 2003, 38, 791.  A. Monge, F. J. Martínez-Crespo, A. López de Ceráin, J. A. Palop, S. Narro, V. Senador, A. Marín, Y. Sáinz, M. González, E. Hamilton, A. J. Barker, J. Med. Chem. 1995, 38,  E. Zamalloa, I. Aldana, C. M. Bachiller, A. Monge, Arzneimittelforsch. 1997, 47, 873.  E. Zamalloa, C. Dios-Viéitez, E. González-Peña, A. Monge, Arzneimittelforsch. 1997, 47,  A. Monge, J. A. Palop, A. López de Ceráin, V. Senador, F. J. Martínez-Crespo, Y. Sáinz, S. Narro, E. García, C. De Miguel, M. González, E. Hamilton, A. J. Barker, E. D. Clarke, D. T. Greenhow, J. Med. Chem. 1995, 38,  M. Vieites, P. Noblía, M. H. Torre, H. Cerecetto, M. L. Lavaggi, A. J. C. Filho, A. Azqueta, A. L. Cerain, A. Monge, B. Parajón-Costa, M. González, D. Gambino, J. Inorg. Biochem. 2006, 100,  M. H. Torre, D. Gambino, J. Araujo, H. Cerecetto, M. González, M.L. Lavaggi, A. Azqueta, A. L. Cerain, A. Monge-Vega, U. Abram, A.J. Costa-Filho, Eur. J. Med. Chem. 2005, 40, 473.  C. Urquiola, D. Gambino, M. Cabrera, M. L. Lavaggi, H. Cerecetto, M. González, A. L. Cerain, A. Monge, A. Costa-Filho, M. H. Torre, J. Inorg. Biochem. 2008, 102, 119.  C. Urquiola, M. Vieites, G. Aguirre, A. Marín, B. Solano, G. Arrambide, M. L. Lavaggi, M. H. Torre, M. González, A. Monge, D. Gambino, H. Cerecetto, Bioorg. Med. Chem. 2006, 14,  M. B. Tarallo, C. Urquiola, A. Monge, F. R. Pavan, C. Q. Leite, M. H. Torre, D. Gambino, Met. Ions Biol. Med. 2008, 10, 865.  A. Tovar-Tovar, L. Ruiz-Ramírez, A. Campero, A. Romerosa, R. Moreno-Esparza, M. J. Rosales-Hoz, J. Inorg. Biochem. 2004, 98,  M. Takaya, Yakugaku Zasshi 2005, 125 (10), 829.  J. A. Washington II, Manual of Clinical Microbiology, in Lennete E.H., Balows, A., Hausler W.J., Shadomy H.J. (Eds.), Susceptibility Tests: Agar Dilution, ASM Press, Washington, 1985, pp  A. L. Barry, C. Thornsberry, Manual of Clinical Microbiology, in Lennete E.H., Balows, A., Hausler W.J., Shadomy H.J. (Eds.), Susceptibility Tests: Diffusion Test Procedures, ASM Press, Washington, 1985, pp  S. G. Franzblau, R. S. Witzig, J. C. McLaughlin, P. Torres, G. Madico, A. Hernandez, M. T. Degnan, M. B. Cook, V. K. Quenzer, R. M. Ferguson, R. H. Gilman, J. Clin. Microbiol. 1998, 36, 362.  A. Monge, J.A. Palop, A. Piñol, F. J. Martínez-Crespo, S. Narro, M. González, Y. Sainz, A. L. de Ceráin, J. Heterocyclic Chem. 1994, 31,  N. M. Karayannis, L. L. Pytlewski, C. M. Mikulski, Coord. Chem. Rev. 1973, 11, 93.
10 89 M. B. Tarallo et al.  A. Cuevas, I. Viera, M. H. Torre, E. Kremer, S. B. Etcheverry, E. J. Baran, Acta Farm. Bonaerense 1998, 17(3), 213.  K. Nakamoto, Infrared and Raman spectra of Inorganic and Coordination Compounds, Part B, John Wiley and Sons, New York,  A. Bencini, D. Gatteschi, EPR of Exchange Coupled Systems, Springer-Verlag, Berlin, 1990, pp  E. D. Vieira, G. Facchin, M. H. Torre, A. J. Costa-Filho, J. Braz. Chem. Soc., 2008, 19,  T. Vänngärd, Copper Proteins, in Swartz H.M., Bolton J.R., Borg D.C. (Eds.), Biological Applications of Electron Spin Resonance, Wiley-Interscience, New York, 1972, pp  R.L.Belford, D.C. Duan, J. Magn. Reson. 1978, 29, 293.
Infrared Spectroscopy 紅 外 線 光 譜 儀 Introduction Spectroscopy is an analytical technique which helps determine structure. It destroys little or no sample (nondestructive method). The amount of light absorbed
Human serum albumin (HSA) nanoparticles stabilized with intermolecular disulfide bonds Wentan Wang, Yanbin Huang*, Shufang Zhao, Ting Shao and Yi Cheng* Department of Chemical Engineering, Tsinghua University,
Test Method for the Continuous Reduction of Bacterial Contamination on Copper Alloy Surfaces Test Organisms: Staphylococcus aureus (ATCC 6538) Enterobacter aerogenes (ATCC 13048) Pseudomonas aeruginosa
Determining the Structure of an Organic Compound The analysis of the outcome of a reaction requires that we know the full structure of the products as well as the reactants In the 19 th and early 20 th
CHEM 51LB: EXPERIMENT 5 SPECTROSCOPIC METHODS: INFRARED AND NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY REACTIONS: None TECHNIQUES: IR, NMR Infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy are
UTILIZATION of PLASMA ACTIVATED WATER in Biotechnology, Pharmacology and Medicine JSC TECHNOSYSTEM-ECO Moscow, Russia April, 2009 METHOD of WATER ACTIVATION with PLASMA of GAS DISCHARGE ANODE VACUUM WATER
International Journal of Environmental, Chemical, Ecological, Geological and Geophysical Engineering Vol:3, No:1, 29 Bioleaching of Heavy Metals from Sewage Sludge Using Indigenous Iron-Oxidizing Microorganisms:
NUKLEONIKA 2013;58(3):413 418 ORIGINAL PAPER EPR studies of free radicals in thermally sterilized famotidine Paweł Ramos, Barbara Pilawa, Edyta Stroka Abstract. Free radicals formation in thermally sterilized
INFRARED SPECTROSCOPY (IR) Theory and Interpretation of IR spectra ASSIGNED READINGS Introduction to technique 25 (p. 833-834 in lab textbook) Uses of the Infrared Spectrum (p. 847-853) Look over pages
Molecular Spectroscopy UV-Vis Spectroscopy Absorption Characteristics of Some Common Chromophores UV-Vis Spectroscopy Absorption Characteristics of Aromatic Compounds UV-Vis Spectroscopy Effect of extended
2nd/3rd Year Physical Chemistry Practical Course, Oxford University 2.02 DETERMINATION OF THE FORMULA OF A COMPLEX BY SPECTROPHOTOMETRY (4 points) Outline Spectrometry is widely used to monitor the progress
LAB 4. Cultivation of Bacteria Protocols for use of cultivation of bacteria, use of general growth, enriched, selective and differential media, plate pouring, determination of temperature range for growth
Disc Diffusion Susceptibility Methods Introduction When a filter paper disc impregnated with a chemical is placed on agar the chemical will diffuse from the disc into the agar. This diffusion will place
COURSE TITLE COURSE DESCRIPTION CH-00X CHEMISTRY EXIT INTERVIEW All graduating students are required to meet with their department chairperson/program director to finalize requirements for degree completion.
CHEMISTRY Department Office Darwin Hall 300 (707) 664-2119 www.sonoma.edu/chemistry Department Chair Lynn R. Cominsky Administrative Coordinator Cathi Cari-Shudde Faculty Steven Farmer Meng-Chih Su *Dale
Supporting Information Simple and Rapid Synthesis of Ultrathin Gold Nanowires, Their Self-Assembly and Application in Surface-Enhanced Raman Scattering Huajun Feng, a Yanmei Yang, a Yumeng You, b Gongping
Nucleic Acid Purity Assessment using A 260 /A 280 Ratios A common practice in molecular biology is to perform a quick assessment of the purity of nucleic acid samples by determining the ratio of spectrophotometric
Polish Journal of Microbiology 2005, Vol. 54, No 1, 21 26 Flow Cytometry Analysis of the Activity of Disinfecting Agents Tested with Staphylococcus aureus and Escherichia coli A. WO NIAK-KOSEK and J. KAWIAK*
Chem 306 Section (Circle) M Tu W Th Name Partners Date ANALYSIS OF ASPIRIN INFRARED (IR) SPECTROSCOPY AND MELTING POINT DETERMINATION Materials: prepared acetylsalicylic acid (aspirin), stockroom samples
Chapter 7 Lecture Notes: Control of Microbes by Physical and Chemical Agents I. Definitions A. Antimicrobial agent = general terms for an agent that kills microbes or inhibits their growth 1. prefix designates
Lab Exercise 3: Media, incubation, and aseptic technique Objectives 1. Compare the different types of media. 2. Describe the different formats of media, plate, tube etc. 3. Explain how to sterilize it,
Test report l on tiles with HT coating Author: Dr. Kerstin Hund-Rinke Client: Deutsche Steinzeug Cremer & Breuer AG Servaisstr. 53347 Alfter-Witterschlick Test institute: Fraunhofer Institute for Molecular
Time out states and transitions Spectroscopy transitions between energy states of a molecule excited by absorption or emission of a photon hν = E = E i -E f Energy levels due to interactions between parts
Chemical Sciences Journal, Volume 2011: CSJ-26 1 Synthesis and Characterization of Polyaniline/Gold Nanocomposites *V Sridevi, S Malathi, CS Devi Department of Chemistry, Lady Doak College, Madurai 625
Call 2014: High throughput screening of therapeutic molecules and rare diseases The second call High throughput screening of therapeutic molecules and rare diseases launched by the French Foundation for
Department of Chemistry College of Science Sultan Qaboos University Title : CHEM 3326 (Applied Spectroscopy) Credits : 3 Course Format : 2 lectures and 2 tutorials Course Text : Spectrometric Identification
Back to Basics Fundamentals of Polymer Analysis Using Infrared & Raman Spectroscopy Molecular Spectroscopy in the Polymer Manufacturing Process Process NIR NIR Production Receiving Shipping QC R&D Routine
OVERALL: 93/100 Presentation: 9/10 Crystallization of Oxobis(2,4-pentanediono)vanadium(IV) via Reduction of Vanadium(V) Oxide Arya Stark Instructor: Dr. Scott Oliver TA: Yashar Abdollahian Chem 151L, Section
DETERMINACIÓN DE ESTRUCTURAS ORGÁNICAS (ORGANIC SPECTROSCOPY) IR SPECTROSCOPY Hermenegildo García Gómez Departamento de Química Instituto de Tecnología Química Universidad Politécnica de Valencia 46022
Cautions: 6 M hydrochloric acid is corrosive. Purpose: To colorimetrically determine the mass of iron present in commercial vitamin tablets using a prepared calibration curve. Introduction: Iron is considered
CHEM CHEMISTRY Note: See beginning of Section F for abbreviations, course numbers and coding. CHEM 1041 General Chemistry I 3 ch (3C 1T) Introductory course designed primarily for B.Sc. students. Topics
Coordination Compounds with Copper (II) Prelab (Week 2) Name Total /10 SHOW ALL WORK NO WORK = NO CREDIT 1. What is the purpose of this experiment? 2. Write the generic chemical formula for the coordination
Cat. No. CS-330 Amount 1 Kit For in vitro use only. Quality guaranteed for 3 months. Store at 4 C. Application Screen for thermal stability of proteins as a function of the FUNDAMENTAL variables ph and
s for Chapter PRBLEM Assuming that the molecular ion is the base peak (00% abundance) what peaks would appear in the mass spectrum of each of these molecules: (a) C5Br (b) C60 (c) C64Br In cases (a) and
SUPPLEMENTARY FIGURES Fig. S1: Effect of ISO- and TAC-treatments on the biosynthesis of FAS-II elongation products in M. tb H37Ra. LC/MS chromatograms showing a decrease in products with elemental compositions
Ultraviolet Spectroscopy The wavelength of UV and visible light are substantially shorter than the wavelength of infrared radiation. The UV spectrum ranges from 100 to 400 nm. A UV-Vis spectrophotometer
INSTRUCTIONS FOR USE READY-TO-USE PLATED MEDIA PA-255082.02 Rev.: June 2003 BD Modified CNA Agar BD Modified CNA Agar with Crystal Violet INTENDED USE BD Modified CNA Agar is a selective medium for the
Biological Sciences Initiative HHMI Student Activities Measuring Antibiotic Resistance Introduction: You might be aware that antibiotics were once thought of as a magic bullet; a nearly perfect drug for
Journal of the University of Chemical M. Georgiev, Technology D. Stoilova and Metallurgy, 42, 2, 2007, 211-216 METAL-WATER INTERACTINS AND HYDRGEN BND STRENGTH M. Georgiev 1, D. Stoilova 2 1 University
Different Varieties of Plantain (Banana) and Their Estimation by Chemical Tests C.Tamil Selvi & Dr. A. Mukunthan Department of Physics, Bharath Institute of Higher Education And Research, Chennai 600073,
New solutions for in-can preservation in the making for Europe ABSTRACT Anders Carlsen* and Gerhard Tiedtke*, *Dow Microbial Control, Buchs SG, Switzerland Due to increasing restrictions on many traditional
EXPERIMENT 5 Molecular Absorption Spectroscopy: Determination of Iron With 1,10-Phenanthroline UNKNOWN Submit a clean, labeled 100-mL volumetric flask to the instructor so that your unknown iron solution
JOURNAL OF CHEMISTRY AND CHEMICAL SCIENCES An International Open Free Access, Peer Reviewed Research Journal www.chemistry-journal.org ISSN 2229-760X (Print) ISSN 2319-7625 (Online) Abbr: J. Chem. & Cheml.
UNIVERSITÄTSKLINIK FÜR INNERE MEDIZIN I Abteilung für Infektionen und Chemotherapie Mikrobiologische Laboratorien 3P Univ. Prof. DDr. A. Georgopoulos Währinger Gürtel 18-20, A - 1090 Wien, Austria Tel.:
Organic Spectroscopy Methods for structure determination of organic compounds: X-ray rystallography rystall structures Mass spectroscopy Molecular formula -----------------------------------------------------------------------------
Fighting the Battles: Conducting a Clinical Assay 6 Vocabulary: In Vitro: studies in biology that are conducted using components of an organism that have been isolated from their usual biological surroundings
Lecture 3 Dr. Ismail I. Daood Medical Microbiology Culture Media : Culture media are used for recognition and identification (diagnosis) of microorganisms. The media are contained in plates (Petri dishes),
contamination analysis for compound semiconductors ANALYTICAL SERVICES B u r i e d d e f e c t s, E v a n s A n a l y t i c a l g r o u p h e l p s y o u C O N T R O L C O N T A M I N A T I O N Contamination
Evaluation of Microbial Growth and Survival on Construction materials treated with Anabec NewBuild 30 Absar Alum, Ph.D. Department of Civil and Environmental Engineering Arizona State University Tempe,
International Journal of Electronic and Electrical Engineering. ISSN 0974-2174, Volume 7, Number 2 (2014), pp. 159-164 International Research Publication House http://www.irphouse.com Effect of ph on the
March 2011 Susceptibility Testing of Mycobacteria, Nocardiae, and Other Aerobic Actinomycetes; Approved Standard Second Edition This standard provides protocols and related quality control parameters and
CHAPTER 10 BACTERIAL GROWTH Eye of Science / Science Photo Library WHY IS THIS IMPORTANT? Increase in numbers is one of the requirements for infection. This increase is dependent upon bacterial growth.
Est. 1984 ORIENTAL JOURNAL OF CHEMISTRY An International Open Free Access, Peer Reviewed Research Journal www.orientjchem.org ISSN: 0970-020 X CODEN: OJCHEG 2012, Vol. 28, No. (1): Pg. 189-202 The Unshifted
CHEM 122L General Chemistry Laboratory Revision 2.0 The Synthesis of trans-dichlorobis(ethylenediamine)cobalt(iii) Chloride To learn about Coordination Compounds and Complex Ions. To learn about Isomerism.
Chemistry 111 Laboratory Experiment 7: Determination of Reaction Stoichiometry and Chemical Equilibrium Introduction The word equilibrium suggests balance or stability. The fact that a chemical reaction
Send To: 1X220 Ms. Laura Marshall AcornVac, Inc. 13818 Oaks Avenue Chino CA 91710 United States Facility: 1X221 AcornVac, Inc. 13818 Oaks Avenue Chino CA 91710 United States Result: COMPLETE Report Date:
Experiment #5: Qualitative Absorption Spectroscopy One of the most important areas in the field of analytical chemistry is that of spectroscopy. In general terms, spectroscopy deals with the interactions
CHEM 331L Physical Chemistry Laboratory Revision 1.0 Determination of Equilibrium Constants using NMR Spectrscopy In this laboratory exercise we will measure a chemical equilibrium constant using key proton
Analysis of Riboflavin in a Vitamin Pill by Fluorescence Spectroscopy** Objectives In this lab, you will use fluorescence spectroscopy to determine the mass and percentage of riboflavin in a vitamin pill.
Enantiomers: Synthesis, characterization, and resolution of tris(ethylenediamine)cobalt(iii) chloride Introduction: The development of coordination chemistry prior to 1950 involved the synthesis and characterization
Bulg. J. Phys. 34 (2007) 103 107 Hydrogen Bonds in Water-Methanol Mixture G.M. Georgiev, K. Vasilev, K. Gyamchev Faculty of Physics, University of Sofia 5J.Bourchier Blvd., 1164 Sofia, Bulgaria Received
Comparison of the antibacterial activities of different brands of Ciprofloxacin Comparación de la actividad antibacterial de diferentes marcas de Ciprofloxacina Muhammad Shahid NAZIR MUGHAL, Muhammad Tahir
NMR and other Instrumental Techniques in Chemistry and the proposed National Curriculum. Dr. John Jackowski Chair of Science, Head of Chemistry Scotch College Melbourne firstname.lastname@example.org
Lab 10: Bacterial Transformation, part 2, DNA plasmid preps, Determining DNA Concentration and Purity Today you analyze the results of your bacterial transformation from last week and determine the efficiency
Electronic Supplementary Material (ESI) for Chemical Science. This journal is The Royal Society of Chemistry 2015 A Ratiometric NMR ph Sensing Strategy Based on Slow- Proton-Exchange (SPE) Mechanism Loïse
Spectroscopic Determination of a Complex Ion's Stoichiometry by Job's Method ABSTRACT This experiment is adapted from Angelici's classic experiment, but uses Fe(H 2 O) 6-n (SCN) n 3-n as the complex ion.
Simplified Removal of Chelated Metals Sultan I. Amer, AQUACHEM INC. Metal Finishing, April 2004, Vol. 102 No. 4 Chelating agents are used in large quantities in industrial applications involving dissolved
18.2 Protein Structure and Function: An Overview Protein: A large biological molecule made of many amino acids linked together through peptide bonds. Alpha-amino acid: Compound with an amino group bonded
Combinatorial Chemistry and solid phase synthesis seminar and laboratory course Topic 1: Principles of combinatorial chemistry 1. Introduction: Why Combinatorial Chemistry? Until recently, a common drug
ISS: 0973-4945; CDE ECJHA E- Chemistry http://www.ejchem.net 2012, 9(2), 875-882 Synthesis, Characterization and Antimicrobial Studies of a ew Mannich Base -[Morpholino (phenyl)methyl]acetamide and Its
Supporting Information to Cu Nanoparticles Enables Plasmonic-Improved Silicon Photovoltaic Devices Michele L. de Souza, a Paola Corio a and Alexandre G. Brolo, *b a Instituto de Química, Universidade de
Problem Set 6 UV-Vis Absorption Spectroscopy 13-1. Express the following absorbances in terms of percent transmittance: a 0.051 b 0.918 c 0.379 d 0.261 e 0.485 f 0.072 A = log P o /P = log1/t = - log T
Peptides: Synthesis and Biological Interest Therapeutic Agents Therapeutic peptides approved by the FDA (2009-2011) 3 Proteins Biopolymers of α-amino acids. Amino acids are joined by peptide bond. They
u Chapter 15 Infrared Spectroscopy: Theory An important tool of the organic chemist is Infrared Spectroscopy, or IR. IR spectra are acquired on a special instrument, called an IR spectrometer. IR is used
DEPARTMENT OF CHEMISTRY Through the Department of Chemistry, courses (CHEM) are offered at the undergraduate level for students pursuing the Bachelor of Science Degree (B.S.) in Chemistry, for students
Accepted for Publication, Published online October 13, 2014; doi:10.4269/ajtmh.14-0018. The latest version is at http://ajtmh.org/cgi/doi/10.4269/ajtmh.14-0018 In order to provide our readers with timely
Electronic Structure and the Periodic Table Learning Outcomes (a) Electronic structure (i) Electromagnetic spectrum and associated calculations Electromagnetic radiation may be described in terms of waves.
Spectrophotometry Reading assignment:. http://en.wikipedia.org/wiki/beer-lambert_law Goals We will study the spectral properties of a transition metal-containing compound. We will also study the relationship
EXPERIMENT 11 UV/VIS Spectroscopy and Spectrophotometry: Spectrophotometric Analysis of Potassium Permanganate Solutions. Outcomes After completing this experiment, the student should be able to: 1. Prepare
Electronic upplementary Material (EI) for New Journal of Chemistry This journal is The Royal ociety of Chemistry and The Centre National de la Recherche cientifique 2014 upporting Information of ensitive
Unit title: Chemical Laboratory Techniques Unit code: H/601/0355 QCF level: 4 Credit value: 15 Aim This unit gives learners the opportunity to practise and become proficient in a range of practical skills