Medium Optimization for Exopolysaccharide Production in Liquid Culture of Endophytic Fungus Berkleasmium sp. Dzf12

Berkleasmium sp. Dzf12, an endophytic fungus from Dioscorea zingiberensis, is a high producer of spirobisnaphthalenes with various bioactivities. The exopolysaccharide (EPS) produced by this fungus also shows excellent antioxidant activity. In this study, the experimental designs based on statistics were employed to evaluate and optimize the medium for EPS production in liquid culture of Berkleasmium sp. Dzf12. For increasing EPS yield, the concentrations of glucose, peptone, KH₂PO₄, MgSO₄·7H₂O and FeSO₄·7H₂O in medium were optimized using response surface methodology (RSM). Both the fractional factorial design (FFD) and central composite design (CCD) were applied to optimize the main factors which significantly affected EPS production. The concentrations of glucose, peptone and MgSO₄·7H₂O were found to be the main effective factors for EPS production by FFD experimental analysis. Based on the further CCD optimization and RSM analysis, a quadratic polynomial regression equation was derived from the EPS yield and three variables. Statistical analysis showed the polynomial regression model was in good agreement with the experimental results with the determination coefficient (adj-R²) as 0.9434. By solving the quadratic regression equation, the optimal concentrations of glucose, peptone and MgSO₄·7H₂O for EPS production were determined as 63.80, 20.76 and 2.74 g/L, respectively. Under the optimum conditions, the predicted EPS yield reached the maximum (13.22 g/L). Verification experiment confirmed the validity with the actual EPS yield as 13.97 g/L, which was 6.29-fold in comparison with that (2.22 g/L) in the original basal medium. The results provide the support data for EPS production in large scale and also speed up the application of Berkleasmium sp. Dzf12.     

Optimization of Influential Nutrients during Direct Cellulose Fermentation into Hydrogen by Clostridium thermocellum

Combinatorial effects of influential growth nutrients were investigated in order to enhance hydrogen (H₂) production during direct conversion of cellulose by Clostridium thermocellum DSM 1237. A central composite face-centered design and response surface methodology (RSM) were applied to optimize concentrations of cellulose, yeast extract (YE), and magnesium chloride (Mg) in culture. The overall optimum composition generated by the desirability function resulted in 57.28 mmol H₂/L-culture with 1.30 mol H₂/mol glucose and 7.48 mmol/(g·cell·h) when cultures contained 25 g/L cellulose, 2 g/L YE, and 1.75 g/L Mg. Compared with the unaltered medium, the optimized medium produced approximately 3.2-fold more H₂ within the same time-frame with 50% higher specific productivity, which are also better than previously reported values from similar studies. Nutrient composition that diverted carbon and electron flux away from H₂ promoting ethanol production was also determined. This study represents the first investigation dealing with multifactor optimization with RSM for H₂ production during direct cellulose fermentation.     

In Vitro Activity of Copper(II) Complexes,Loaded or Unloaded into a Nanostructured Lipid System,against Mycobacterium tuberculosis

Tuberculosis (TB) is an infectious disease caused mainly by the bacillus Mycobacterium tuberculosis (Mtb), presenting 9.5 million new cases and 1.5 million deaths in 2014. The aim of this study was to evaluate a nanostructured lipid system (NLS) composed of 10% phase oil (cholesterol), 10% surfactant (soy phosphatidylcholine, sodium oleate), and Eumulgin^® HRE 40 ([castor oil polyoxyl-40-hydrogenated] in a proportion of 3:6:8), and an 80% aqueous phase (phosphate buffer pH = 7.4) as a tactic to enhance the in vitro anti-Mtb activity of the copper(II) complexes [CuCl₂(INH)₂]·H₂O (1), [Cu(NCS)₂(INH)₂]·5H₂O (2) and [Cu(NCO)₂(INH)₂]·4H₂O (3). The Cu(II) complex-loaded NLS displayed sizes ranging from 169.5 ± 0.7095 to 211.1 ± 0.8963 nm, polydispersity index (PDI) varying from 0.135 ± 0.0130 to 0.236 ± 0.00100, and zeta potential ranging from −0.00690 ± 0.0896 to −8.43 ± 1.63 mV. Rheological analysis showed that the formulations behave as non-Newtonian fluids of the pseudoplastic and viscoelastic type. Antimycobacterial activities of the free complexes and NLS-loaded complexes against Mtb H₃₇Rv ATCC 27294 were evaluated by the REMA methodology, and the selectivity index (SI) was calculated using the cytotoxicity index (IC₅₀) against Vero (ATCC^® CCL-81), J774A.1 (ATCC^® TIB-67), and MRC-5 (ATCC^® CCL-171) cell lines. The data suggest that the incorporation of the complexes into NLS improved the inhibitory action against Mtb by 52-, 27-, and 4.7-fold and the SI values by 173-, 43-, and 7-fold for the compounds 1, 2 and 3, respectively. The incorporation of the complexes 1, 2 and 3 into the NLS also resulted in a significant decrease of toxicity towards an alternative model (Artemia salina L.). These findings suggest that the NLS may be considered as a platform for incorporation of metallic complexes aimed at the treatment of TB.     

Effect of Exogenous Factors on Bacteriocin Production from Lactobacillus paracasei J23 by Using a Resting Cell System

A resting cell system was developed for bacteriocin Lac-B23 production from Lactobacillus paracasei J23. The resting cell medium contained (g/L): Glucose 20, Sodium acetate 5.0, MnSO₄ 0.25 MgSO₄ 0.5, Ammoniumhydrogencitrate 1.0, KH₂PO₄ 1.0. The resting cell incubation time and temperature were 20 h and 37 °C and the effects of exogenous factors, including amino acids, glycerol, pyruvic acid, and α-ketoglutaric acid were investigated. Cys and Gly could stimulate the production of bacteriocin, while no stimulus effect was observed for Glu, Tyr and Ala. Glycerol and pyruvic acid increased bacteriocin production and the optimum concentrations were 1% and 30 g/L, respectively. Bacteriocin could act as an inducer of its own biosynthesis. These findings are of importance for the further study of bacteriocin biosynthesis regulation and for the improvement of bacteriocin production yields.     

Bioethanol production from corn meal by simultaneous enzymatic saccharification and fermentation with immobilized cells of Saccharomyces cerevisiae var. ellipsoideus

The simultaneous enzymatic saccharification and fermentation (SSF) of corn meal using immobilized cells of Saccharomycescerevisiae var. ellipsoideus yeast in a batch system was studied. The yeast cells were immobilized in Ca-alginate by electrostatic droplet generation method. The process kinetics was assessed and determined and the effect of addition of various yeast activators (mineral salts: ZnSO₄ · 7H₂O and MgSO₄ · 7H₂O, and vitamins: Ca-pantothenate, biotin and myo-inositol) separately or mixed, was investigated. Taking into account high values of process parameters (such as ethanol concentration, ethanol yield, percentage of the theoretical ethanol yield, volumetric productivity and utilized glucose) and significant energy savings the SSF process was found to be superior compared to the SHF process. Further improvement in ethanol production was accomplished with the addition of mineral salts as yeast activators which contributed to the highest increase in ethanol production. In this case, the ethanol concentration of 10.23% (w/w), percentage of the theoretical ethanol yield of 98.08%, the ethanol yield of 0.55 g/g and the volumetric productivity of 2.13 g/l·h were obtained.     

Structural Diversity of Copper(II) Complexes with 9-Deazahypoxanthine and Their in Vitro SOD-Like Activity

Two structurally different copper(II) complexes of the compositions [{Cu(9dhx)(H₂O)₃}₂(µ-SO₄)₂] (1) and [Cu(9dhx)₂(H₂O)₂(NO₃)₂]·H₂O (2), involving 9-deazahypoxanthine (9dhx; 6-oxo-9-deazapurine; 9-deazahypoxanthine), have been prepared and characterized by elemental analysis, infrared and electronic spectroscopy, electrospray ionisation (ESI) mass spectrometry, thermogravimetric (TG) and differential thermal (DTA) analyses, and cyclic voltammetry. The X-ray structures of complexes 1 and [Cu(9dhx)₂(H₂O)₂(NO₃)₂] (2a) revealed the distorted octahedral geometry in the vicinity of the copper(II) atoms, with the NO₅ and N₂O₄ donor set, respectively. In the dimeric compound 1, the {Cu(9dhx)(H₂O)₃}₂ units are bridged by sulfate groups with the Cu···Cu separation being 5.3446(2) Å. In both structures the 9dhx ligands are coordinated through the N3 atoms of the pyrimidine moieties. The SOD-like activity of complexes 1 and 2 was evaluated in vitro showing moderate effect, with the IC₅₀ values equal to 18.20, and 53.33 μM, respectively.     

Bacterial Cellulose Production from Industrial Waste and by-Product Streams

The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102–138 g·water/g·dry bacterial cellulose, viscosities of 4.7–9.3 dL/g, degree of polymerization of 1889.1–2672.8, stress at break of 72.3–139.5 MPa and Young’s modulus of 0.97–1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients.     

A High Redox Potential Laccase from Pycnoporus sanguineus RP15: Potential Application for Dye Decolorization

Laccase production by Pycnoporus sanguineus RP15 grown in wheat bran and corncob under solid-state fermentation was optimized by response surface methodology using a Central Composite Rotational Design. A laccase (Lacps1) was purified and characterized and the potential of the pure Lacps1 and the crude culture extract for synthetic dye decolorization was evaluated. At optimal conditions (eight days, 26 °C, 18% (w/w) milled corncob, 0.8% (w/w) NH₄Cl and 50 mmol·L⁻¹ CuSO₄, initial moisture 4.1 mL·g⁻¹), the laccase activity reached 138.6 ± 13.2 U·g⁻¹. Lacps1 was a monomeric glycoprotein (67 kDa, 24% carbohydrate). Optimum pH and temperature for the oxidation of 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) were 4.4 and 74.4 °C, respectively. Lacps1 was stable at pH 3.0–8.0, and after two hours at 55–60 °C, presenting high redox potential (0.747 V vs. NHE). ABTS was oxidized with an apparent affinity constant of 147.0 ± 6.4 μmol·L⁻¹, maximum velocity of 413.4 ± 21.2 U·mg⁻¹ and catalytic efficiency of 3140.1 ± 149.6 L·mmol⁻¹·s⁻¹. The maximum decolorization percentages of bromophenol blue (BPB), remazol brilliant blue R and reactive blue 4 (RB4), at 25 or 40 °C without redox mediators, reached 90%, 80% and 60%, respectively, using either pure Lacps1 or the crude extract. This is the first study of the decolorization of BPB and RB4 by a P. sanguineus laccase. The data suggested good potential for treatment of industrial dye-containing effluents.     

Bioactive Chemical Constituents from the Brown Alga Homoeostrichus formosana

A new chromene derivative, 2-(4'',8''-dimethylnona-3''E,7''-dienyl)-8-hydroxy-2,6-dimethyl-2H-chromene (1) together with four known natural products, methylfarnesylquinone (2), isololiolide (3), pheophytin a (4), and β-carotene (5) were isolated from the brown alga Homoeostrichus formosana. The structure of 1 was determined by extensive 1D and 2D spectroscopic analyses. Acetylation of 1 yielded the monoacetylated derivative 2-(4'',8''-dimethylnona-3''E,7''-dienyl)-8-acetyl-2,6-dimethyl-2H-chromene (6). Compounds 1–6 exhibited various levels of cytotoxic, antibacterial, and anti-inflammatory activities. Compound 2 was found to display potent in vitro anti-inflammatory activity by inhibiting the generation of superoxide anion (IC₅₀ 0.22 ± 0.03 μg/mL) and elastase release (IC₅₀ 0.48 ± 0.11 μg/mL) in FMLP/CB-induced human neutrophils.     

Nickel(II) Coordination Polymers Supported by Bis-pyridyl-bis-amide and Angular Dicarboxylate Ligands: Role of Ligand Flexibility in Iodine Adsorption

Reactions of N‚N’-bis(3-pyridylmethyl)oxalamide (L¹), N‚N’-bis(4-pyridylmethyl)oxalamide (L²), or N,N’-bis(3-pyridylmethyl)adipoamide) (L³) with angular dicarboxylic acids and Ni(II) salts under hydro(solvo)thermal conditions afforded a series of coordination polymers: {[Ni(L¹)(OBA)(H₂O)]·H₂O}_n (H₂OBA = 4,4-oxydibenzoic acid), 1, {[Ni(L¹)(SDA)(H₂O)₂]·H₂O·CH₃OH}_n (H₂SDA = 4,4-sulfonyldibenzoic acid), 2, {[Ni(L²)(OBA)]·C₂H₅OH}_n, 3, {[Ni(L²)(OBA)]·CH₃OH}_n, 4, {[Ni₂(L²)(SDA)₂(H₂O)₃]·5H₂O}_n, 5, {[Ni₂(L²)(SDA)₂(H₂O)₃]·H₂O·2C₂H₅OH}_n, 6, {[Ni(L³)(OBA)(H₂O)₂]·2H₂O}_n, 7, {[Ni(L³)(SDA)(H₂O)₂]·2H₂O}_n, 8, and {[Ni(L³)₀.₅(SDA)(H₂O)₂]·0.5C₂H₅OH}_n, 9, which have been structurally characterized by using single-crystal X-ray crystallography. Complex 1 exhibits an interdigitated 2D layer with the 2,4L2 topology and 2 is a 2D layer with the sql topology, while 3 and 4 are 3D frameworks resulting from polycatenated 2D nets with the sql topology and 5 and 6 are 2-fold interpenetrated 3D frameworks with the dia topology. Complexes 7 and 8 are 1D looped chains and 9 is a 2D layer with the 3,4L13 topology. The various structural types in 1–9 indicate that the structural diversity is subject to the flexibility and donor atom position of the neutral spacer ligands and the identity of the angular dicarboxylate ligands, while the role of the solvent is uncertain. The iodine adsorption of 1–9 was also investigated, demonstrating that that the flexibility of the spacer L¹–L³ ligands can be an important factor that governs the feasibility of the iodine adsorption. Moreover, complex 9 shows a better iodine adsorption and encapsulates 166.55 mg g⁻¹ iodine in the vapor phase at 60 °C, which corresponded to 0.38 molecules of iodine per formula unit.     

In situ growth of CuInS2 nanocrystals on nanoporous TiO2 film for constructing inorganic/organic heterojunction solar cells

Inorganic/organic heterojunction solar cells (HSCs) have attracted increasing attention as a cost-effective alternative to conventional solar cells. This work presents an HSC by in situ growth of CuInS₂(CIS) layer as the photoabsorption material on nanoporous TiO₂ film with the use of poly(3-hexylthiophene) (P3HT) as hole-transport material. The in situ growth of CIS nanocrystals has been realized by solvothermally treating nanoporous TiO₂ film in ethanol solution containing InCl₃ · 4H₂O, CuSO₄ · 5H₂O, and thioacetamide with a constant concentration ratio of 1:1:2. InCl₃ concentration plays a significant role in controlling the surface morphology of CIS layer. When InCl₃ concentration is 0.1 M, there is a layer of CIS flower-shaped superstructures on TiO₂ film, and CIS superstructures are in fact composed of ultrathin nanoplates as ‘petals’ with plenty of nanopores. In addition, the nanopores of TiO₂ film are filled by CIS nanocrystals, as confirmed using scanning electron microscopy image and by energy dispersive spectroscopy line scan analysis. Subsequently, HSC with a structure of FTO/TiO₂/CIS/P3HT/PEDOT:PSS/Au has been fabricated, and it yields a power conversion efficiency of 1.4%. Further improvement of the efficiency can be expected by the optimization of the morphology and thickness of CIS layer and the device structure.     

An Amphiprotic Novel Chitosanase from Bacillus mycoides and Its Application in the Production of Chitooligomers with Their Antioxidant and Anti-Inflammatory Evaluation

The objectives of this investigation were to produce a novel chitosanase for application in industries and waste treatment. The transformation of chitinous biowaste into valuable bioactive chitooligomers (COS) is one of the most exciting applications of chitosanase. An amphiprotic novel chitosanase from Bacillus mycoides TKU038 using squid pen powder (SPP)-containing medium was retrieved from a Taiwan soil sample, which was purified by column chromatography, and characterized by biochemical protocol. Extracellular chitosanase (CS038) was purified to 130-fold with a 35% yield, and its molecular mass was roughly 48 kDa. CS038 was stable over a wide range of pH values (4–10) at 50 °C and exhibited an optimal temperature of 50 °C. Interestingly, the optimum pH values were estimated as 6 and 10, whereas CS038 exhibited chitosan-degrading activity (100% and 94%, respectively). CS038 had K_m and V_max values of 0.098 mg/mL and 1.336 U/min, separately, using different concentrations of water-soluble chitosan. A combination of the high performance liquid chromatography (HPLC) and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometer data revealed that the chitosan oligosaccharides obtained from the hydrolysis of chitosan by CS038 comprise oligomers with multiple degrees of polymerization (DP), varying from 3–9, as well as CS038 in an endolytic fashion. The TKU038 culture supernatant and COS mixture exhibited 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities. The COS activities were dose dependent and correlated to their DP. The COS with high DP exhibited enhanced DPPH radical scavenging capability compared with COS with low DP. Furthermore, the COS exhibited inhibitory behavior on nitric oxide (NO) production in murine RAW 264.7 macrophage cells, which was induced by Escherichia coli O111 lipopolysaccharide (LPS). The COS with low DP possesses a more potent anti-inflammatory capability to decrease NO production (IC₅₀, 76.27 ± 1.49 µg/mL) than that of COS with high DP (IC₅₀, 82.65 ± 1.18 µg/mL). Given its effectiveness in production and purification, acidophilic and alkalophilic properties, stability over ranges of pH values, ability to generate COS, antioxidant activity, and anti-inflammatory, CS038 has potential applications in SPP waste treatment and industries for COS production as a medical prebiotic.     

Enrichment of Secondary Wastewater Sludge for Production of Hydrogen from Crude Glycerol and Comparative Evaluation of Mono-, Co- and Mixed-Culture Systems

Anaerobic digestion using mixed-culture with broader choice of pretreatments for hydrogen (H₂) production was investigated. Pretreatment of wastewater sludge by five methods, such as heat, acid, base, microwave and chloroform was conducted using crude glycerol (CG) as substrate. Results for heat treatment (100 °C for 15 min) showed the highest H₂ production across the pretreatment methods with 15.18 ± 0.26 mmol/L of medium at 30 °C in absence of complex media and nutrient solution. The heat-pretreated inoculum eliminated H₂ consuming bacteria and produced twice as much as H₂ as compared to other pretreatment methods. The fermentation conditions, such as CG concentration (1.23 to 24 g/L), percentage of inoculum size (InS) (1.23% to 24% v/v) along with initial pH (2.98 to 8.02) was tested using central composite design (CCD) with H₂ production as response parameter. The maximum H₂ production of 29.43 ± 0.71 mmol/L obtained at optimum conditions of 20 g/L CG, 20% InS and pH 7. Symbiotic correlation of pH over CG and InS had a significant (p-value: 0.0011) contribution to H₂ production. The mixed-culture possessed better natural acclimatization activity for degrading CG, at substrate inhibition concentration and provided efficient inoculum conditions in comparison to mono- and co-culture systems. The heat pretreatment step used across mixed-culture system is simple, cheap and industrially applicable in comparison to mono-/co-culture systems for H₂ production.     

The study on the application of solid-state method for synthesizing the polyaniline/noble metal (Au or Pt) hybrid materials

The solid-state method was applied for synthesizing polyaniline (PANI)/noble metal hybrid materials with the presence of HAuCl₄·4H₂O or H₂PtCl₆·6H₂O in the reaction medium. The structure, morphology, and electrochemical activity of the composites were characterized by Fourier transform infrared (FTIR) spectra, UV-visible (vis) absorption spectra, energy dispersive spectrum (EDS), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and cyclic voltammetry. The results from FTIR and UV-vis spectra showed that the oxidation degree and doping level of the PANI in composites can be influenced by HAuCl₄·4H₂O and H₂PtCl₆·6H₂O. The EDS data demonstrated that the composites contain a certain amount of Au (or Pt) element. XRD analysis indicated the presence of crystalline-state Au particles in PANI matrix prepared from the presence of HAuCl₄·4H₂O and revealed that the H₂PtCl₆·6H₂O cannot be converted into metal Pt. The TEM and SEM images implied that the Au particles did exist in the polymer matrix with the size of about 20 nm. The enzymeless H₂O₂ sensor constructed with PANI/Au composite from the presence of HAuCl₄·4H₂O showed a short response time (within 5 s) and displayed an excellent performance in wide linear range.     

The role of environmental factors and medium composition on bacteriocin production by an aquaculture probiotic Enterococcus faecium MC13 isolated from fish intestine

The aim of this study was to optimize medium composition for higher yield of total viable cells and bacteriocin by Enterococcus faecium MC13. The factors such as peptone, meat extract, yeast extract, lactose, glycerol, tween 80, triammonium citrate and K₂HPO₄ were selected based on the Lactobacillus MRS medium composition. Two level factorial designs (FD) and steepest ascent path were performed to identify vital factors among the variables. Through the 2^?8 FD, peptone, yeast extract and lactose were found to be significant factors involved in the enhanced production of viable cells and bacteriocin. Therefore, these three foremost factors were further optimized by central composite design to achieve efficient yield. The optimum MRS composition was found to be peptone (40.0 g/L), meat extract (30.0 g/L), yeast extract (40.0 g/L), lactose (24.0 g/L), glycerol (5.8 g/L), Tween 80 (3.0 g/L), triammonium citrate (1.0 g/L), K₂HPO₄ (2.5 g/L), MgSO₄·7H₂O (0.10 g/L), MnSO₄·7H₂O (0.05 g/L) and dipotassium PO₄ (2.0 g/L). The optimized growth medium allowed higher amount of bacteriocin activity (36,100 AUml^?1) and total viable cells (14.22 LogCFUml^?1) production which were two-times higher than the commercial MRS medium.     

Strength after heating of unfired refractories containing chemical bonding agents

Conclusions Out of all the experimental bonding agents used in the production of unfired magnesite and magnesite-chromite refractories: SDW; MgSO₄,· 7H₂O; MgSO₄·7H₂O + H₃BO₃; (NaPO₃)_n, the greatest strength on heating is provided by the addition of 2% (NaPO₃)_n.An addition of boric acid to the refractories using the MgSO₄,·7H₂O bonding agent helps to strengthen the refractories in the 500–900°C interval; at a higher temperature the refractories with the magnesium sulfate plus boric acid bonding have no advantages in their strength properties over the articles with the magnesium sulfate bonding agent only.The magnesite-chromite articles with the chemical bonding agent have better strength in the 1000–1400°C interval than the magnesite articles. This is explained by the spinelformation reactions which occur at these temperatures.On the basis of these studies (NaPO₃)_n and also MgSO₄,· 7H₂O with an addition of H₃BO₃ can be recommended as chemical bonding agents for unfired magnesite-chromite refractories.Translated from Ogneupory, No. 1, pp. 48–52, January, 1979.     

Studies on cultivation and biological activities ofPleurotus nebrodensis inzenga

Environmental factors affecting mycelial growth and exo-polysaccharide production fromPleurotus nebrodensis Inzenga (PN) and biological activities of PN extractsin vitro were studied. The culture conditions for effective mycelial growth and exo-polysaccharide production were found to be 25 ‡C, 5% of inoculum size, and an initial pH from 6.5 to 7.0. When 5% of glucose was used, the maximum mycelial growth and exo-polysaccharide concentrations were 8.3 and 3.07 g/L, respectively. Among the various nitrogen sources, the mycelial growth and exo-polysaccharide production were very strong when polypeptone was used. In the case of the minerals sources, K₂HPO₄ and MgSO₄·7H₂O were found to best support for mycelial growth and exo-polysaccharide production. Under optimal conditions and methods, the maximum mycelial growth and exo-polysaccharide production were obtained after 10 days of culture, 12.84 and 4.85 g/L, respectively, in a jar fermentor. The effects of the PN extracts on the viability of three human cancer cell lines and antioxidant activity were investigatedin vitro. When cancer cells of the lung (A549), cervical region (HeLa) and colon (KM12C) were incubated at 6 mg/mL of the PN ethanol extracts, the viabilities of the HeLa and KM12C cells were slightly decreased. However, the growth of the A549 cells was remarkably inhibited when the PN ethanol extract was over 4 mg/mL. The antioxidant activity showed 46.2% at 40 μL, which was about 3.2 fold higher than that of the PN methanol extract.     

Synthesis and Characterization of Some New Bis-Pyrazolyl-Thiazoles Incorporating the Thiophene Moiety as Potent Anti-Tumor Agents

A new series of 1,4-bis(1-(5-(aryldiazenyl)thiazol-2-yl)-5-(thiophen-2-yl)-4,5-dihydro-1H-pyrazol-3-yl)benzenes 3a–i were synthesized via reaction of 5,5′-(1,4-phenylene)bis(3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carbothioamide) (1) with hydrazonoyl halides 2a–i. In addition, reaction of 1 with ethyl chloroacetate afforded bis-thiazolone derivative 8 as the end product. Reaction of compound 8 with methyl glyoxalate gave bis-thiazolone derivative 10. The structures of the newly synthesized compounds were established on the basis of spectroscopic evidences and their alternative syntheses. All the synthesized compounds were evaluated for their anti-tumor activities against hepatocellular carcinoma (HepG2) cell lines, and the results revealed promising activities of compounds 3g, 5e, 3e, 10, 5f, 3i, and 3f with IC₅₀ equal 1.37 ± 0.15, 1.41 ± 0.17, 1.62 ± 0.20, 1.86 ± 0.20, 1.93 ± 0.08, 2.03 ± 0.25, and 2.09 ± 0.19 μM, respectively.     

Supramolecular Coordination Polymers by Self-assembling of Bis-monodentate Ligands with HgI2

Two supramolecular coordination polymers, [HgI₂(L¹)·0.5H₂O]_∞ (1) and [HgI₂(L²)·0.4CH₃OH]_∞ (2), have been prepared by ligands L¹ (L¹ = bis[4-(4- pyridylmethyleneamino)phenyl] ether) and L² (L² = N,N′-bis(3-pyridylmethyl)-diphthalic diimide) with HgI₂, respectively. 1 formed an interestingly infinite cross-linked double helical structure, whereas 2 formed the one-dimensional zigzag chains, which are parallel with each other.     

Relationship between Antioxidant Activity and Ligand Basicity in the Dipicolinate Series of Oxovanadium(IV) and Dioxovanadium(V) Complexes

Oxidative stress plays an important role in the pathogenesis of many serious diseases, including cancer, atherosclerosis, coronary artery disease, Parkinson’s disease, Alzheimer’s disease, stroke and myocardial infarction. In the body’s natural biochemical processes, harmful free radicals are formed, which can be removed with the help of appropriate enzymes, a balanced diet or the supply of synthetic antioxidant substances such as flavonoids, vitamins or anthocyanins to the body. Due to the growing demand for antioxidant substances, new complex compounds of transition metal ions with potential antioxidant activity are constantly being sought. In this study, four oxovanadium(IV) and dioxovanadium(V) dipicolinate (dipic) complexes with 1,10-phenanthroline (phen), 2,2′-bipyridyl (bipy) and the protonated form of 2-phenylpyridine (2-phephyH): (1) [VO(dipic)(H₂O)₂]·2 H₂O, (2) [VO(dipic)(phen)]·3 H₂O, (3) [VO(dipic)(bipy)]·H₂O and (4) [VOO(dipic)](2-phepyH)·H₂O were synthesized including one new complex, so far unknown and not described in the literature, i.e., [VOO(dipic)](2-phepyH)·H₂O. The oxovanadium(IV) dipicolinate complexes with 1,10-phenanthroline and 2,2′-bipyridyl have been characterized by several physicochemical methods: NMR, MALDI-TOF-MS, IR, but new complex [VOO(dipic)](2-phepyH)·H₂O has been examined by XRD to confirm its structure. The antioxidant activities of four complexes have been examined by the nitrotetrazolium blue (NBT) method towards superoxide anion. All complexes exhibit high reactivity with superoxide anion and [VOO(dipic)](2-phepyH)·H₂O has higher antioxidant activity than L-ascorbic acid. Our studies confirmed that high basicity of the auxiliary ligand increases the reactivity of the complex with the superoxide radical.