Journal of Molecular Structure 1137 (2017) 742e755
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Journal of Molecular Structure journal homepage: http://www.elsevier.com/locate/molstruc
Synthesis, characterization and antioxidant/cytotoxic activity of oxovanadium(IV) complexes of methyliminodiacetic acid and ethylenediaminetetracetic acid Mohamed M. Ibrahim a, b, *, Gaber A.M. Mersal b, c, Abdel-Motaleb M. Ramadan a, Shaban Y. Shaban a, Mahmoud A. Mohamed d, Salih Al-Juaid e a
Department of Chemistry, Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt Chemistry Department, Faculty of Science, Taif University, Taif, Saudi Arabia Departmentof Chemistry, Faculty of Science, South Valley University, Egypt d Faculty of Agriculture, Department of Biochemistry, Cairo University, Cairo, Egypt e Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia b c
a r t i c l e i n f o
a b s t r a c t
Article history: Received 19 June 2016 Received in revised form 20 February 2017 Accepted 21 February 2017 Available online 27 February 2017
Two oxovanadium(IV) complexes, viz., [VO(Me-IDA)(H2O)2] (1) and NaH[VO(EDTA)]$4H2O (2) (MeIDA ¼ methyliminodiacetic acid and EDTA ¼ ethylenediaminetetraacetic acid) have been synthesized and characterized by FT-IR, UVeVis, mass spectrometry, elemental analysis, magnetic moment and thermal analysis, as well as electrochemical measurements including cyclic voltammetry. Both compounds are monomeric with distorted octahedral geometries. Compound 2 has been structurally characterized by using X-ray crystallography. It shows an octahedral V(O)N2O3 coordination geometry, which exhibits chemically significant hydrogen bonding interactions besides showing coordination polymer formation. Compounds 1 and 2 show an irreversible redox peak around þ0.80 V versus Ag/AgCl corresponding to one-electron oxidation of V(IV) to V(V). The free radical scavenging activity of compounds 1 and 2 were done using 2,2-diphenyl- 1-picrylhydrazyl (DPPH). Both compounds have shown encouraging ROS scavenging activities. The cytotoxicity effects of both compounds toward two different tumor cells (HePG2 and MCF-7) have been also studied by MTT assay. The IC50 values obtained, after 48 h incubation at 37 C for HepG2 and MCF-7 cell lines were 74.23 and 42.04 mg/mL for compound 1 and 65.56 and 48.34 mg/mL for compound 2, respectively. Conclusively, the present investigation provides preliminary results which suggest that such compounds can be promising alternative antitumor agents. © 2017 Elsevier B.V. All rights reserved.
Keywords: Synthesis Oxovanadium(IV) complexes X-ray structure Antioxidant Cytotoxicity
1. Introduction Reactive oxygen species (ROS) sometimes called as active oxygen species, are various forms of activated oxygen, which include free radicals such as superoxide ions (O$ 2 ) and hydroxyl radicals (OH) as well as non-free radical species such as hydrogen peroxide (H2O2) [1]. These ROS play an important role in degenerative or pathological processes, such as aging, cancers, coronary heart diseases, Alzheimer's disease, neurodegenerative disorders, atherosclerosis, cataracts and inflammations [2]. Living organisms have antioxidant defense systems that protects against oxidative
* Corresponding author. Department of Chemistry, Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt. E-mail address:
[email protected] (M.M. Ibrahim). http://dx.doi.org/10.1016/j.molstruc.2017.02.080 0022-2860/© 2017 Elsevier B.V. All rights reserved.
damage by removal or repair of damaged molecules [3]. The term ‘antioxidant’ refers to the activity of numerous vitamins, minerals and phytochemicals which provide protection against the damage caused by ROS [4]. Antioxidants interfere with the oxidative processes by scavenging free radicals, chelating free catalytic metals and by acting as electron donors [5]. The biological effects of vanadium and its pharmacological activity are areas of increasing research interest [6e8]. The potentiality of simple vanadium compounds as therapeutic agents has been repeatedly emphasized in recent years and its insulin mimetic [9e12], anti-tumoral [13e16], anti-parasitic [17] and anti-microbial activities [18] have been reported. Inorganic vanadium salts are poorly absorbed from the digestive system, thus high oral doses are required. Therefore, various vanadium ionseorganic ligand complexes were tested in order to obtain more potent medicines than inorganic vanadium
M.M. Ibrahim et al. / Journal of Molecular Structure 1137 (2017) 742e755
O O H2O
O V
O
O
O
O
O
V
O
OH2
N
O
O
N
N
O
(1)
(2)
O OH
Scheme 1. The proposed structures of oxovanadium(IV) complexes 1 and 2.
Table 1 Sample and crystal data of oxovanadium(IV) complex 2. Chemical formula Formula weight Temperature Wavelength Crystal size Crystal system Space group Unit cell dimensions
C10H21N2NaO13V 451.22 g/mol 100(2) K 0.71073 Å 0.060 0.080 0.600 mm orthorhombic P 21 21 21 a ¼ 6.4690(2) Å b ¼ 13.9309(5) Å c ¼ 19.5692(7) Å 1763.56(10) Å3 4 1.699 g/cm3 0.659 mm1 932
Volume Z Density (calculated) Absorption coefficient F(000)
a ¼ 90 b ¼ 90 g ¼ 90
Table 2 Data collection and structure refinement of oxovanadium(IV) complex 2. Theta range for data collection Index ranges Reflections collected Independent reflections Max. and min. transmission Refinement method Refinement program Function minimized Data/restraints/parameters Goodness-of-fit on F2 D/smax Final R indices Weighting scheme Absolute structure parameter Largest diff. peak and hole R.M.S. deviation from mean
2.08e28.35 5 ¼ h
