| SM ISO690:2012|
CILOCI (DESEATNIC), Alexandra; BULHAK, Ion; BOLOGA, Olga; TIURINA, Janeta; CLAPCO, Steliana; BIVOL, Cezara; DVORNINA, Elena; LABLIUC, Svetlana. Coordination compounds of Zn and Mo with macrocyclic ligands derived from 2.6-diformyl-4-methylphenol and their biological properties. In: Physical Methods in Coordination and Supramolecular Chemistry. XVIII, 8-9 octombrie 2015, Chişinău. Chisinau, Republic of Moldova: 2015, p. 49.
|Physical Methods in Coordination and Supramolecular Chemistry
Conferința ""Physical Methods in Coordination and Supramolecular Chemistry"" |
Chişinău, Moldova, 8-9 octombrie 2015
In recent years, it was found that the complexes of transition metals play a significant role in the processes occurring in living organisms, showing a stimulatory or inhibitory (antiviral, antimicrobial, antitumor etc.) effect on their growth and development. They also serve as potential regulators of the biosynthesis of biologically active substances, including a variety of extracellular enzymes of the microorganisms. The condensation of the malonic acid dihydrazide with 2.6-diformyl-4-methylphenol in the presence of the molybdenum acetylacetonate or zinc nitrate as a result of the template reaction on the matrix of those metals, led to creation of complexes with the most simple formulas MoO2(L-2H)·2H2O and Zn(L-2H)·H2O. The IR spectra of the obtained compounds showed absence of the absorption bands in the region 3400-3200 cm-1 (ν(NH2), that in the spectrum of the malonic acid dihydrazide appeared at 3298 and 3200 cm-1. Also the absorption bands are missing in the region 1680-1640 cm-1 (ν(C=O)), but in the spectrum of the malonic acid dihydrazide were present at 1664 and 1646 cm-1 and in the spectrum of the 2.6-diformyl-4-methylphenol were appeared at 1679 cm-1. This confirmed the condensation of the organic components. The change in position of the absorption bands (ν(C=O)) in the spectrum of the complexes at 1623 cm-1 for zinc compound and at 1618 cm-1 for molybdenum compound demonstrated that the carbonyl groups of the dihydrazide of the Schiff base coordinate the metal atoms. The lack of the absorption bands of the complexes in the spectra δ(OHphenol), which in the spectrum of 2.6-diformyl-4-methylphenol appeared at 1214 cm-1, has confirmed that this group coordinates to the metal in the deprotonated form. Evaluation of the biological properties of the obtained compounds was performed by assessing the effect of these compounds on the process of enzymogenesis of the micromycete Aspergillus niger CNMN FD-06. The strain refers to the "black aspergillus" and is an active producer of amylolytic enzymes which can hydrolyze starch as in standard conditions (at pH 4.7) and in extremely acidic conditions (at pH 2.5). This extends the possibilities of its use in the biotechnological productions. The maximal enzyme activity of the standard (pH 4.7) and acid-stable (pH 2.5) amylases of the strain was observed in the 5th day of the cultivation and in this experiment was 50.68 U/ml and 56.56 U/ml, respectively. The results showed that the complexes had an inhibitory effect at all concentrations on the activity of both types of amylases synthesized by the micromycete. With the increase of the concentration of the complexes was enhanced the inhibitory effect. Thus, using the complex №1 in the 5th day of cultivation the inhibitory effect of the standard amylase increased from 25.1% (at 5 mg/L) to 45.1% (at 15 mg/L), and for acid-stable amylase – from 37.7% (at 5 mg/L) to 52.9% (at 15 mg/L).The inhibitory effect was stronger in the case of the complex №2 and was of 35.1% (at 5 mg/L) - 55.2% (at 15 mg/L) for standard amylase and of 59.9% (at 5 mg/L) - 67.0% (at 15 mg/L) for the acid-stable amylase. Thus, it was revealed that the tested complexes have inhibitory effect on some aspects of the metabolism of micromycete Aspergillus niger CNMN FD 06, which allows to suggest the possibility of their use for controlling plant diseases.