Effects of a cold atmospheric pressure plasma (CAPP) treatment on the germination, production of biomass, vigor of seedlings, uptake of water of wheat seeds (
Triticum aestivum
L. cv. Eva) were ...investigated. The CAPP treatment influence on the inactivation of microorganisms occurring on the surface of wheat seeds was investigated also. The so-called Diffuse Coplanar Surface Barrier Discharge generating a cold plasma in ambient air with high power volume density of some 100 W/cm
3
was used for the treatment of seeds at exposure times in the range of 10–600 s. The optical emission spectroscopy and the electrical measurements were used for estimation of CAPP parameters. The obtained results indicate that the germination rate, dry weight and vigor of seedlings significantly increased for plasma treatment from 20 to 50 s. The plasma treatment of seeds led to an extensive increase in wettability and faster germination comparing with the untreated seeds. The growth inhibition effect of CAPP on the surface microflora of wheat seeds increased with the increase of the treatment time. The efficiency of the treatment of wheat seeds artificially contaminated with pure cultures of filamentous fungi decreased in the following order:
Fusarium nivale
>
F
.
culmorum
>
Trichothecium roseum
>
Aspergillus flavus
>
A. clavatus
.
The interaction of a copper complexes containing Schiff bases with calf thymus (CT) DNA was investigated by spectroscopic methods. UV–vis, fluorescence and CD spectroscopies were conducted to assess ...their binding ability with CT DNA. The binding constants
K have been estimated from 0.8 to 9.1
×
10
4
M
−1. The percentage of hypochromism is found to be over 70% (from spectral titrations). The results showed that the copper(II) complexes could bind to DNA with an intercalative mode. Synergic action of Cu(II) complexes with ascorbic acid against
Candida albicans induced the generation of free radicals and increased (more than 60 times) antimicrobial effect of these complexes.
Trinuclear Ag(I) (1) and dinuclear and mononuclear Zn(II) isonicotinate (2 and 3) complexes were prepared and characterized by X-ray crystallography, elemental analysis, IR spectroscopy, and thermal ...analysis. Single-crystal analysis of the Ag(I) complex reveals two different monodentate carboxylate coordination modes, protonated and deprotonated, respectively. IR spectra showed correlations between isonicotinate coordination modes and Δ(ν
as
− ν
s
)
IR
values. In addition, the hydrogen bonds significantly influence a position of carboxylate absorption bands. Moreover, IC
50
and MIC data for bacteria, yeasts, and filamentous fungi were determined and the binding of Ag(I) and Zn(II) complexes to calf thymus DNA was investigated using electronic absorption, fluorescence, and CD measurements. Biological tests showed that the Ag(I) complex is more active than commercially used Ag(I) sulfadiazine against Escherichia coli. The fluorescence spectral results indicate that the complexes can bind to DNA through an intercalative mode. The Stern-Volmer quenching constants for investigated complexes obtained from the linear quenching plot are in the range of 1.67 × 10
4
-3.42 × 10
4
M
−1
.
Silver(I) pyridinecarboxylates (AgPIC (1), AgNIC (2), Ag(HDIPIC)·0.75H
2
O (3), PIC = picolinate, NIC = nicotinate, HDIPIC = dipicolinate) were prepared by solvothermal syntheses and their ...characterization were completed by elemental, spectral, and thermal analyses. To assign the pyridinecarboxylate coordination mode in the complexes, detailed mid-infrared spectral data and Δ(ν
as
− ν
s
) comparisons were accomplished. In addition, silver(I) pyridinecarboxylate antimicrobial activities and stability by
1
H NMR spectra were determined. Moreover, the spectral, thermal, and antimicrobial properties of silver(I) and previously prepared zinc(II) pyridinecarboxylates were compared and discussed.
Application of UV radiation to the strain
Trichoderma
sp. T-bt (isolated from lignite) resulted in the T-brm mutant which was resistant to the systemic fungicide benomyl. The
tub2
gene sequence in ...the T-brm mutant differed from the parent as well as the collection strain (replacing tyrosine with histidine in the TUB2 protein). Under
in vitro
conditions this mutant exhibited a higher mycoparasitic activity toward phytopathogenic fungi.
Kojic acid (5-hydroxy-2-hydroxymethyl-4-pyranone) represents an attractive polyfunctional skeleton for development of biologically active compounds. The authors prepared a great variety of kojic acid ...derivatives and selected biological properties have been studied. Thus, kojic acid derivatives are promising compounds that might advantageously be used in human and/or veterinary medicine and also in preparation of new, even more biologically active preparations.
Antifungal activity of new copper(II) complexes of 2-methylthionicotinate (2-MeSNic) of the composition Cu(2-MeSNic)2(MeNia)(2).4H2O (where MeNia is N-methylnicotinamide), and ...Cu(2-MeSNic)2(Nia)(2).2H2O (where Nia is nicotinamide) and Cu(2-MeSNic)2L2 (where L is isonicotinamide, iNia, or ethyl nicotinate, EtNic) were tested on various strains of filamentous fungi by the macrodilution method. Most sensitive against copper(II) adducts with bioactive ligands were Rhizopus oryzae and Microsporum gypseum (IC50 1.5-2.3 mmol/L). The adducts with Nia, MeNia and EtNic at 5 mmol/L induced morphological changes in growing hyphae of Botrytis cinerea, mainly their intensive branching attached to release of cytoplasm with partial growth inhibition. Inhibition of sporulation (> 90%) of Alternaria alternata by Cu(2-MeSNic)2.H2O was observed as a change in the color of the colonies. The highest resistance was marked by B. cinerea and Fusarium moniliforme (average IC50 values 4.25 and 3.13 mmol/L, respectively). The presence of all bioactive ligands in copper(II) complexes caused an increase in the inhibition effect against model fungi (except significant inhibition activity of EtNic on R. oryzae).
The growth and conidiation of the aged Trichoderma viride culture grown in the dark, and after an induction by a light pulse, was examined in the presence of selected mono-, di(tri)saccharides, amino ...acids and alcohols as sole carbon sources. Hexoses and disaccharides, but not pentoses and amino acids, promoted proportionally both growth and conidiation induced by aging or light. All compounds but pentoses promoted the conidiation in aged cultures and photoconidiation in a close correlation. Ethanol, glycerol and ethylene glycol supported both growth and conidiation but these processes were not supported equally. Conidia formation with hexoses and amino acids as sole carbon sources seems to be a function of growth promotion, rather than of growth restriction (starvation, stress, aging). With glucose as sole carbon source the conidiation was not triggered by nutrient limitation, nor by the accumulation of waste metabolites. The aging-induced conidiation can be considered to be triggered by the genetic program of the microorganism rather than by its nutrient status.
Reaction of an ethanolic solution of N-salicylidene-
l
-glutamatodiaquacopper(II) monohydrate with pyridine, 2-methylpyridine, 4-methylpyridine, 2-aminopyridine, 2,6-diaminopyridine, quinoline, ...2-methylquinoline, 4-methylquinoline or 3-methylisoquinoline resulted in solid products containing complexes of the type Cu(sal-
l
-glu)L with distorted square-pyramidal coordination geometry. The products were characterized by elemental analysis, electronic spectroscopy and magnetic susceptibility measurements. Antimicrobial effects were tested on various strains of bacteria, yeasts and filamentous fungi. To compare the influence of individual ligands (neutral as well as anionic) on their biological activity, copper(II) complexes containing water and a Schiff base derived from salicyldehyde and methyl- and ethyl-esters of
l
-glutamic acid Cu(sal-5-Me-
l
-glu)(H
2
O)
2
and Cu(sal-5-Et-l-glu)(H
2
O)
2
were also prepared and studied. Bioactivities of complexes tested were found to decrease in the sequence bacteria > filamentous fungi > yeasts.
