Linear polyurethanes with imidazoquinazoline rings: preparation and properties evaluation

Abstract: In this work, research concerning the synthesis and properties of linear polyurethanes (PUs) with the imidazoquinazoline rings was represented. Reaction conditions of 2,6-bis(2-hydroxyethyl)-1-phenylimida-zo[1,5-c]quinazoline-3,5-dione (BHPIQ) with 1,6-hexamethylene diisocyanate were determined and optimized. These conditions are adapted to reaction of BHPIQ with 4,4′-diphenylmethane diisocyanate and 2,4-toluene diisocyanate. New PUs with imidazoquinazoline rings were characterized by spectral methods ( 1 H-NMR and IR spectroscopies), which confirm their structures. Their molar masses and dispersity index were measured by size exclusion chromatography method. The wide-angle X-ray scattering and differential scanning calorimetry (DSC) studies have shown that all PUs based on BHPIQ are amorphous. Moreover, thermal properties of PUs were investigated by thermogravimetry analysis, standard DSC, and temperature-modulated DSC methods. During thermogravimetric measurements, the exhaust gases were analyzed by FTIR method. Incorporation of imidazoquinazoline ring into the PU chains escalates their glass transition temperature; thus, their heat resistance was enhanced. Furthermore, their degradation rate and the amount of released degradation products were reduced. The investigated properties of the obtained PUs with imidazoquinazoline rings were compared with those ones of suitable PUs based on 1,4-butanediol. Graphical abstract: Linear polyurethanes were obtained in reaction of 1-phenyl-2,6-bis(2-hydroxyethylimidazo[1,5-c]quinazoline-3,5-dione with hexamethylene 1,6-diisocyanate, 4,4′-diphenylmethane diisocyanate and toluene 2,4-diisocyanate. Their composition and structure were confirmed. The phase contents and thermal properties were investigated[Figure not available: see fulltext.]. © 2019, The Author(s).DS budge

Solid-State Fermentation Reduces Phytic Acid Level, Improves the Profile of Myo-Inositol Phosphates and Enhances the Availability of Selected Minerals in Flaxseed Oil Cake

U radu su ispitani in vitro sljedeći parametri: udjel fitata (InsP6), svojstva mioinozitol fosfata i iskoristivost esencijalnih mineralnih tvari iz lanene pogače fermentirane s pomoću gljivice Rhizopus oligosporus (DSM 1964 i ATCC 64063). Maseni udjel fitata u lanenoj pogači bio je 13,9 mg/g, nakon 96 sati fermentacije s pomoću R. oligosporus DSM 1964 smanjen je za 48 %, a s pomoću R. oligosporus ATCC 64063 za 33 %. Fermentacijom s pomoću soja DSM 1964 postignuti su bolji rezultati, jer je dobiven dominantni mioinozitol InsP3-5, dok je fermentacijom s pomoću soja ATCC 64603 dobiven uglavnom InsP5-6. Fermentacijom na čvrstoj podlozi od lanene pogače poboljšana je in vitro iskoristivost kalcija za 14 %, magnezija za 3,3 % i fosfora za 2-4 %.Flaxseed oil cake was subjected to fermentation with Rhizopus oligosporus (DSM 1964 a nd ATCC 64063), and the phytate (InsP6) content, myo-inositol phosphate profile and in vitro bioavailability of essential minerals were studied. Flaxseed oil cake had a phytate mass fraction of 13.9 mg/g. A 96-hour fermentation of flaxseed oil cake by R. oligo sporus DSM 1964 and R. oligosporus ATCC 64063 decreased the InsP6 content by 48 and 33 %, respectively. The strains had different phytate-degrading activities: fermentation of flaxseed oil cake with R. oligosporus DSM 1964 was more advantageous, yielding InsP3-5 as a predominating myo-inositol compound, while fermentation with R. oligosporus ATCC 64603 produced predominantly InsP5-6. Solid-state fermentation of flaxseed oil cake enhanced in vitro bioavailability of calcium by 14, magnesium by 3.3 and phosphorus by 2–4 %

Enzymatically Extracted Apple Pectin Possesses Antioxidant and Antitumor Activity

The biological activity of apple pectin extracted conventionally or enzymatically using endo-xylanase and endo-cellulase, was tested in vitro. The analyses were performerd in tetraplicates and the statistical significance of the differences were assessed using ANOVA, Tukey post hoc and LSD (the least significant difference) tests. Multivariate regression analysis was applied to determine the structural components that have a crucial importance for antioxidant and antitumor properties of pectins. The pectins extracted by enzymes contained up to four times more ferulic acid and showed twice as great ability to neutralize free radicals and Fe(III) reduction. The antiradical potential positively correlated with phenols, fucose and rhamnose content. In the assays performed on HT-29 human adenocarcinoma and B16F10 melanoma cell cultures, the “green” pectins, contrary to acid isolated ones, exhibited remarkable anti-neoplastic potential while being nontoxic to nontransformed L929 cell line. The pectins in the dose of 1 mg/mL were capable of inhibiting adhesion (max 23.1%), proliferation (max 40.4%), invasion (max 76.9%) and anchorage-independent growth (max 90%) of HT-29 cells (significance level p < 0.001). These pectin preparations were slightly less active towards B16F10 cells. The enzyme-isolated apple pectins may be useful as a functional food additive and an ingredient of the ointment formulas for post-surgical melanoma treatment

Enzymatically Extracted Apple Pectin Possesses Antioxidant and Antitumor Activity

The biological activity of apple pectin extracted conventionally or enzymatically using endo-xylanase and endo-cellulase, was tested in vitro. The analyses were performerd in tetraplicates and the statistical significance of the differences were assessed using ANOVA, Tukey post hoc and LSD (the least significant difference) tests. Multivariate regression analysis was applied to determine the structural components that have a crucial importance for antioxidant and antitumor properties of pectins. The pectins extracted by enzymes contained up to four times more ferulic acid and showed twice as great ability to neutralize free radicals and Fe(III) reduction. The antiradical potential positively correlated with phenols, fucose and rhamnose content. In the assays performed on HT-29 human adenocarcinoma and B16F10 melanoma cell cultures, the “green” pectins, contrary to acid isolated ones, exhibited remarkable anti-neoplastic potential while being nontoxic to nontransformed L929 cell line. The pectins in the dose of 1 mg/mL were capable of inhibiting adhesion (max 23.1%), proliferation (max 40.4%), invasion (max 76.9%) and anchorage-independent growth (max 90%) of HT-29 cells (significance level p &lt; 0.001). These pectin preparations were slightly less active towards B16F10 cells. The enzyme-isolated apple pectins may be useful as a functional food additive and an ingredient of the ointment formulas for post-surgical melanoma treatment

Impact of phenolic compounds and vitamins C and E on antioxidant activity of sea buckthorn (Hippophaë rhamnoides L.) berries and leaves of diverse ripening times

Bioactive compounds demonstrating antioxidant activity were analyzed in berries and leaves of nine cultivars of sea buckthorn (Hippophaë rhamnoides L.) of various ripening times. Total polyphenols were ranging between 0.70–3.62 g GAE.kg−1 (berries) and 1.88–3.72 g GAE.kg−1 (leaves). Leaves were significantly richer source of total flavonoids (14.40–49.44 mg RE.kg−1) in comparison with berries (0.55–4.11 mg RE.kg−1). Phenolic compounds, carotenoids and vitamins were determined using high-performance liquid chromatography with a diode array detection. The content of vitamin C was 0.98–3.65 g.kg−1 in berries and 22.81–46.32 g.kg−1 in leaves, vitamin E content was 6.98–29.91 g.kg−1 in berries and 71.54–153.99 g.kg−1 in leaves. Distribution of individual phenolic compounds varied, their total content in berries was considerably lower (76.1–205.2 mg.kg−1) than in leaves (1477.7–8709.0 mg.kg−1). Regarding antioxidant activity, Raisa and Slovan (berries) and Bojan and Maslicnaja (leaves) were evaluated as the best cultivars. © 2019 Elsevier LtdInternal Grant Agency of Tomas Bata University in Zlin [IGA/FT/2019/004

Hybrid nanobiocomposites based on poly(3-hydroxybutyrate) - characterization, thermal and mechanical properties

Poly(3-hydroxybutyrate) is a biopolymer which is used to production of implants in the human body. On the other hand, the physical and mechanical properties of poly(3-hydroxybutyrate) are compared to the properties of isotactic polypropylene what makes poly(3-hydroxybutyrate) possible substitute for polypropylene. Unfortunately, the melting point of poly(3-hydroxybutyrate) is almost equal to its degradation temperature what gives very narrow window of its processing conditions. Therefore, numerous attempts are being made to improve the poly(3-hydroxybutyrate) properties. In the present work, hybrid nanobiocomposites based on poly(3-hydroxybutyrate) as a matrix with the use of organic nanoclay-Cloisite 30B and linear polyurethane as a second filler have been manufactured. The linear polyurethane was based on diphenylmethane 4,4'-diisocyanate and diol with imidazoquinazoline rings. The obtained nanobiocomposites were characterized by X-ray diffraction, scanning and transmission electron microscopies, thermogravimetry, differential scanning calorimetry and their selected mechanical properties were tested. The resulting hybrid nanobiocomposites have intercalated/exfoliated structure. The nanobiocomposites characterize a higher thermal stability and a wider range of processing temperatures compared to the unfilled matrix. The plasticizing influence of nanofillers was also observed. In addition, the mechanical properties of the discussed nanobiocomposites were examined and compared with those ones of the unfilled poly(3-hydroxybutyrate). The new-obtained nanobiocomposites based on poly(3-hydroxybutyrate) containing 1% Cloisite 30B and 5% by mass of the linear of polyurethane characterized the highest improvement of processing conditions. They have the biggest difference between the temperature of degradation and the onset melting temperature, about 100°C. © 2020, Institute of Machine Design and Operation. All rights reserved

Synteza i charakterystyka jednoskładnikowych klejów poliuretanowych na osnowie polieterodiolu Rokopol® D2002

One-part, moisture curing polyurethane (PUR) adhesives based on poly(oxypropylene)diol Rokopol® and 4,4’-diphenylmethylene diisocyanate (MDI) modified with di-isononyl phthalate and a number of inorganic fillers and additives such as carbon black, thixotropic agent, dispersants and dibutyltin dilaurate as curing catalyst were developed. Adhesive curing was followed using dynamic oscillation rheometry and effect of some components on viscoelastic properties of curing materials was discussed. The cured materials were characterized by means of differential scanning calorimetry (DSC) and water contact angle measurements. The adhesive performance of obtained materials in bonding aluminum was evaluated by tensile shear bond strength tests.Opracowano jednoskładnikowe kleje na osnowie diizocyjanianu 4,4’-metylenodifenylu (MDI) i polioksypropylenodiolu z środkami pomocniczymi (ftalanem diizononylu jako plastyfikatorem, napełniaczami: talkiem, haloizytem, modyfikowanym bentonitem; dyspergatorami, sadzą pigmentową i katalizatorem utwardzania – dilaurynianem dibutylocyny). Proces sieciowania analizowano za pomocą reometru z dynamiczną oscylacją. Metodą różnicowej kalorymetrii skaningowej wyznaczano temperaturę zeszklenia, ponadto określano kąt zwilżania i właściwości adhezyjne otrzymanych materiałów przeznaczonych do łączenia spoin Al/Al