The Anti-Adherent Activity of Plant Extracts on Penicillium Commune Spores Causing Cedar Wood Decay: An ESEM Analysis

Decay and deterioration of wood by bacteria and fungi are becoming very serious problems because of the resistance of microorganisms to antimicrobial agents. Thus, this study was aimed at investigating the anti-adhesion effect of Myrtus communis and Thymus vulgaris extracts obtained by classical and ultrasonic extraction, against of Penicillium commune spores isolated from fez Medina cedar wood. According to environmental scanning electron microscopy (ESEM) analysis, the results showed that all extracts tested have proven their ability to inhibit the adhesion of the fungal spores studied. In addition, the extract of each plant obtained by ultrasonication showed a low percentage (47% and 33%) of fungal spores adherent to a wood substrate compared to those recovered by maceration (68%). Furthermore, M. communis extracts have shown outstanding anti-adhesive activity, similar to that demonstrated by those of T. vulgaris. Finally, the treatment of wood by M. communis extracts obtained by ultrasonication showed a very important anti-adhesive activity at a concentration of 20 mg/mL compared to that at 5 mg/mL. Therefore, these extracts can be considered a potential source of bioactive metabolites acting as anti-adhesion molecules in novel formulations for the cedar wood preservation.     

Electrochemical oxidation of terbium(III) in aqueous media: influence of supporting electrolyte on oxidation potential and stability

Journal of Applied Electrochemistry - Apart from the generally dominant trivalent oxidation state, several lanthanides can occur in divalent or tetravalent states as well. Changing the valence...     

Extraction of anthocyanins from Aronia melanocarpa skin waste as a sustainable source of natural colorants

Aronia melanocarpa (Michx.) Elliott (black chokeberry) skin wastes from the production of Aronia fruit juice were extracted using a batch extraction method and a novel integrated extraction‐adsorption process. Optimum conditions for batch extraction were as follows: 60 °C, 3 h, acid (0.1% v/v hydrochloric acid), biomass‐to‐solvent ratio of 1:16, and biomass‐to‐solid phase extraction resin ratio of 1:1. The integrated extraction‐adsorption process gave improved anthocyanin yields of higher quality when the process was performed for 3 h without cooling of the circulating liquid, and with a flow rate of 1.3 ml s^?1. Overall, the new method showed better anthocyanin yield and purity compared with the batch method, increasing the extraction yield by ca. 20% (5.25→6.34 mg g^?1 dry weight of pomace) and increasing anthocyanin content by ca. 40% (19.9%→28.4% w/w dry weight of extract). This method also simplified the process as three steps were eliminated saving time and energy. Furthermore, the integrated extraction‐adsorption method is industrially scalable to produce large quantities of anthocyanins. In the batch method, anthocyanins present in A. melanocarpa skins were identified as cyanidin‐3‐O‐galactoside (38.8%), cyanidin‐3‐O‐arabinoside (6.4%), cyanidin‐3‐O‐glucoside (3.6%), cyanidin‐3‐O‐xyloside (0.5%), and the cyanidin aglycon (50.7%); in the continuous method, anthocyanin content was cyanidin‐3‐O‐galactoside (45.7%), cyanidin‐3‐O‐arabinoside (16%), cyanidin‐3‐O‐glucoside (3.6%), cyanidin‐3‐O‐xyloside (2.7%), and the cyanidin aglycon (32%). The integrated extraction‐adsorption method was shown to be substantially less susceptible to acid‐catalysed anthocyanin decomposition processes. All anthocyanins were derived from only one anthocyanidin parent structure (cyanidin), and only monosaccharide glycosides were identified, which is unusual when compared with other berries that typically have more anthocyanidins and/or greater glycosylation diversity.     

8‐Benzyltetrahydropyrazino[2,1‐f]purinediones: Water‐Soluble Tricyclic Xanthine Derivatives as Multitarget Drugs for Neurodegenerative Diseases

8‐Benzyl‐substituted tetrahydropyrazino[2,1‐f]purinediones were designed as tricyclic xanthine derivatives containing a basic nitrogen atom in the tetrahydropyrazine ring to improve water solubility. A library of 69 derivatives was prepared and evaluated in radioligand binding studies at adenosine receptor (AR) subtypes and for their ability to inhibit monoamine oxidases (MAO). Potent dual‐target‐directed A₁/A_2A adenosine receptor antagonists were identified. Several compounds showed triple‐target inhibition; one of the best compounds was 8‐(2,4‐dichloro‐5‐fluorobenzyl)‐1,3‐dimethyl‐6,7,8,9‐tetrahydropyrazino[2,1‐f]purine‐2,4(1H,3H)‐dione ( 72 ) (human AR: K_i A₁ 217 nM , A_2A 233 nM ; IC₅₀ MAO‐B: 508 nM ). Dichlorinated compound 36 [8‐(3,4‐dichlorobenzyl)‐1,3‐dimethyl‐6,7,8,9‐tetrahydropyrazino[2,1‐f]purine‐2,4(1H,3H)‐dione] was found to be the best triple‐target drug in rat (K_i A₁ 351 nM , A_2A 322 nm; IC₅₀ MAO‐B: 260 nM ), and may serve as a useful tool for preclinical proof‐of‐principle studies. Compounds that act at multiple targets relevant for symptomatic as well as disease‐modifying treatment of neurodegenerative diseases are expected to show advantages over single‐target therapeutics.     

2‐Amino[1,2,4]triazolo[1,5‐c]quinazolines and Derived Novel Heterocycles: Syntheses and Structure–Activity Relationships of Potent Adenosine Receptor Antagonists

2‐Amino[1,2,4]triazolo[1,5‐c]quinazolines were identified as potent adenosine receptor (AR) antagonists. Synthetic strategies were devised to gain access to a broad range of derivatives including novel polyheterocyclic compounds. Potent and selective A₃AR antagonists were discovered, including 3,5‐diphenyl[1,2,4]triazolo[4,3‐c]quinazoline ( 17 , K_i human A₃AR 1.16 nm ) and 5′‐phenyl‐1,2‐dihydro‐3′H‐spiro[indole‐3,2′‐[1,2,4]triazolo[1,5‐c]quinazolin]‐2‐one ( 20 , K_i human A₃AR 6.94 nm ). In addition, multitarget antagonists were obtained, such as the dual A₁/A₃ antagonist 2,5‐diphenyl[1,2,4]triazolo[1,5‐c]quinazoline ( 13 b , K_i human A₁AR 51.6 nm , human A₃AR 11.1 nm ), and the balanced pan‐AR antagonists 5‐(2‐thienyl)[1,2,4]triazolo[1,5‐c]quinazolin‐2‐amine ( 11 c , K_i human A₁AR 131 nm , A_2AAR 32.7 nm , A_2BAR 150 nm , A₃AR 47.5 nm ) and 9‐bromo‐5‐phenyl[1,2,4]triazolo[1,5‐c]quinazolin‐2‐amine ( 11 q , K_i human A₁AR 67.7 nm , A_2AAR 13.6 nm , A_2BAR 75.0 nm , A₃AR 703 nm ). In many cases, significantly different affinities for human and rat receptors were observed, which emphasizes the need for caution in extrapolating conclusions between different species.     

Doppler echocardiograph evaluation of pulmonary hypertension in patients undergoing hemodialysis

Pulmonary hypertension (PH) has been reported in hemodialysis (HD) patients, but data regarding its incidence and mechanisms are scarce. The aims of this study was to evaluate the prevalence of unexplained PH in long-term HD patients, and to examine some possible etiologic factors for its occurrence. The prevalence of PH was estimated by Doppler echocardiography in a cohort of 86 stable patients on HD via arteriovenous access for more than 12 months. All the patients underwent full clinical evaluation, chest radiography, and a standard 12-lead echocardiograph. Laboratory investigation included a mean of 12 months (serum calcium, phosphorus, parathormone (PTH), alkaline phosphatase, lipids, and hemoglobin). Pulmonary hypertension was defined as pulmonary artery systolic pressure >35 mmHg as determined by Doppler echocardiography using the modified Bernoulli equation. Pulmonary hypertension was detected in 23 patients (26.74%). Of those with PH, left ventricular hypertrophy was seen in 13 patients (56.52%), and valvular calcifications in 6 patients (26.08%). There were no significant differences between both groups with regard to age, sex, duration of dialysis, shunt location, and all the biological parameters of the study. The presence of PH was not related to the level of PTH, or the severity of other metabolic abnormalities. This study demonstrates a high prevalence of PH among patients with ESRD receiving long-term HD via surgical arteriovenous access. The role of the vascular access, anemia, or secondary hyperparathyroidism as the etiology of PH in HD patients did not hold in this study.     

Mesoporous Silica Nanoparticles: Selective Surface Functionalization for Optimal Relaxometric and Drug Loading Performances

Mesoporous silica nanoparticles (MSNs) have emerged as promising biomaterials for drug delivery and cell tracking applications, for which MRI is the medical imaging modality of choice. In this contribution, MRI contrast agents (DTPA‐Gd) and polyethylene glycol (PEG) are grafted selectively at the surface of MSNs, in order to achieve optimal relaxometric and drug loading performances. In fact, DTPA and PEG grafting procedures reported until now, have resulted in significant pore obstruction, which is detrimental to the drug delivery function of MSNs. This usually induces a dramatic decrease in surface area and pore volume, thus limiting drug loading capacity. Therefore, these molecules must be selectively grafted at the outer surface of MSNs. In this study, 3D pore network MSNs (MCM‐48‐type) are synthesized and functionalized with a straightforward and efficient grafting procedure in which DTPA and PEG are selectively grafted at the outer surface of MSNs. No pore blocking is observed, and more than 90% of surface area, pore volume and pore diameter are retained. The thus‐treated particles are colloidally stable in SBF and cell culture media, they are not cytotoxic and they have high drug loading capacity. Upon labeling with Gd, the nanoparticle suspensions have strong relaxometric properties (r₂/r₁ = 1.47, r₁ = 23.97 mM^?1 s^?1), which confers a remarkable positive contrast enhancement potential to the compound. The particles could serve as efficient drug carriers, as demonstrated with a model of daunorubicin submitted to physiological conditions. The selective nanoparticle surface grafting procedures described in the present article represent a significant advance in the design of high colloidal stability silica‐based vectors with high drug loading capacity, which could provide novel theranostic nanocompounds.     

Preparation and characterization of electrically semi-conductive polyfuran-coated poly(ethylene terephthalate) fibers

One of the most important textile materials, poly(ethylene terephthalate) (PET) fiber, was coated with a semi-conductive polyfuran (PFu) by in situ oxidative polymerization using FeCl₃ oxidant in solvent mixture of acetonitrile–chloroform. The effects of polymerization conditions such as volume ratios of acetonitrile/chloroform, monomer concentration, and oxidant/monomer mol ratio were investigated on PFu content (%) of the composites. It was observed that pretreatment of PET in dichloromethane increased PFu content and its coating continuity before polymerization. The highest PFu content (12.0%) was obtained using FeCl₃/furan mol ratios of 3.5 in acetonitrile/chloroform mixture (5/1). The density values of the composites with different PFu contents were measured. Composite fibers were also subjected to doping processes with HCl and I₂ vapors, separately, and it was observed that the surface resistivity of PFu/PET (10¹² Ω/cm²) reached to 53 Ω/cm² after doping with I₂. The structural, thermal, and morphological characterization was performed with FTIR, XRD, TGA, and SEM, respectively.