Synthesis,characterization and aggregation and fluorescence properties of novel highly soluble zinc phthalocyanines bearing tetrakis-4-(3-(piperidin-1-yl)phenoxy) with tetra and dodecachloro substituents

The synthesis of two new phthalocyanine precursors 4-(3-(piperidin-1-yl)phenoxy) with mono (2) and trichloro (3) substituents were carried out in this work. Cyclotetramerization of these precursors with zinc acetate gave novel tetrakis-4-(3-(piperidin-1-yl)phenoxy) with tetra (4) and dodecachloro (5) substituted zinc phthalocyanines. The synthesized new compounds were characterized using FT-IR, ¹H NMR, electronic absorption spectroscopy, mass spectra and elemental analysis. The aggregation behavior of zinc phthalocyanines 4 and 5 was investigated in different concentrations of dichloromethane (DCM). Zinc phthalocyanines 4 and 5 showed good solubility in different organic solvents such as DCM, CHCl₃, THF, benzene and toluene. Further, the aggregation behavior of zinc phthalocyanines 4 and 5 was studied before and after the addition of Triton X100. Further, the fluorescence quantum yields of zinc phthalocyanines 4 and 5 were calculated in the presence and absence of Triton X100.     

Synthesis and properties of alkali-clearable azo disperse dyes containing a carboxylic ethyl ester group

Three alkali-clearable azo disperse dyes containing a carboxylic ethyl ester group (D1-D3) were readily synthesized using three different synthetic strategies. D1 was prepared from a carboxylic acid-containing dye by esterification with ethanol. D2 was prepared from a carboxylic ester-containing dye by transesterification with ethanol. D3 was prepared from a cyano group-containing dye by alcoholysis with ethanol and water. The molecular structures of the dyes were characterized by FTIR, mass spectrometry, ¹H NMR, ¹³C NMR, and elemental analysis. The synthesized dyes and the control dyes were used to dye poly(ethylene terephthalate) fabric, and their washing and rubbing fastness properties following different after-treatment methods (reduction clearing and alkali clearing) were examined and compared. The carboxylic ethyl ester-containing disperse dyes show good alkali clearing ability on poly(ethylene terephthalate) fabric and cause fewer environmental issues due to the absence of reductants, no production of aromatic amines with high toxicity and carcinogenicity, as well as the low toxicity of the dye hydrolysate ethanol.     

Synthesis,Characterization, and Dyeing Performance of Thiadiazole Derivatives

N⁴-(5-methyl-1,3,4-thiadiazol-2-yl)thiazole-2,4-diamine derivatives have been synthesized by the reaction of 2-amino-5-methyl-1,3,4-thiadiazole and chloroaecetylchloride with suitable solvent, then cyclized with thiourea at reflux temperature in methanol to yield N⁴-(5-methyl-1,3,4-thiadiazol-2-yl)thiazole-2,4-diamine which was diazotized and coupled with various naphthalene acid couplers to give new series of acid dyes (AD₁-AD₁₃). All the compounds were characterized by their percentage yield, melting point, elemental analysis, UV spectra, IR spectra, and NMR spectra and dyeing performance on nylon fabric has been assessed.     

Delineation of Inheritance Pattern of Aleurone Layer Colour Through Chemical Tests in Rice

Background

Rice aleurone layer develops different colours with various chemical tests that may help to develop some rapid tests for identification/grouping of rice varieties. Understanding the colour inheritance pattern could enable to develop chemical clues that may help for genetic purity analysis along with grow-out-test.

Results

In this study, inheritance pattern of aleurone layer colour was studied in parents, F₁ and F₂ progenies derived from the crosses IR 36 × Acc. No. 2693 and IR 64 × Acc. No. 2693. The parent IR 36 showed light yellow (NaOH/KOH) and brown (phenol/modified phenol test) colour; whereas, Acc. No. 2693 revealed wine red/dark wine red (NaOH/KOH) and light brown colour/no reaction (phenol/modified phenol test). In contrary, another parent IR 64 exhibited light yellow (KOH/NaOH) and dark brown (phenol, modified phenol) colour. Both the F₁ showed an intermediate light wine red colour (NaOH/KOH) and dark brown (phenol and modified phenol) colour, which is dominant over their one of the parents. The colour pattern with standard phenol/modified phenol, NaOH and KOH tests in F₂ progenies of both the crosses showed 9:7 (complementary gene interaction) and 11:5 ratios (reciprocal dominance modification of recessive alleles), respectively.

Conclusions

Our findings clearly elucidate the colour inheritance pattern in rice that may facilitate to develop rapid chemical tests to identify/ group the varieties for genetic purity analysis.

     

Quantitative analyses of individual γ-Oryzanol (Steryl Ferulates) in conventional and organic brown rice (Oryza sativa L.)

γ-Oryzanol (steryl ferulates; SF) has been shown to be a major bioactive compound in rice. To determine the content of individual γ-oryzanols in brown rice by high performance liquid chromatography (HPLC), purification of individual SF for use as an external standard is required. Four main SF were isolated from a commercial γ-oryzanol mixture and identified as cycloartenyl ferulate (1), 24-methylenecycloartanyl ferulate (2), campesteryl ferulate (3), and sitosteryl ferulate (4) based on mass spectrometry and nuclear magnetic resonance spectroscopic data. The SF contents between conventional and organic brown rice were qualitatively determined by HPLC using SF isolated from a commercial γ-oryzanol mixture as the external standard. The total γ-oryzanol content (mg/100 g) in organic brown rice (65.6 ± 2.7) was slightly higher (P < 0.05) than that found in conventional brown rice (60.2 ± 1.8). The content (mg/100 g) of 1 (21.2 ± 0.9) and 4 (9.8 ± 0.4) in organic brown rice was higher (P < 0.05) than that observed in conventional brown rice (1, 18.2 ± 1.1; 4, 8.5 ± 0.3). However, the content of 2 and 3 in the conventional and organic brown rice samples did not differ significantly. These results indicate that the cultivation methods do significantly alter the γ-oryzanol content for conventional and organic brown rice.     

Antioxidant Properties of Extracts Obtained from Raw,Dry-roasted,and Oil-roasted US Peanuts of Commercial Importance

Raw, skinless peanut kernels from US commercial production lines were dry- and oil-roasted according to standard industrial practices. Eighty percent (v/v) methanolic extracts from the peanut cultivars were prepared and characterized by RP-HPLC: five predominant compounds were found comprising free p-coumaric acid and potential p-coumaric acid derivatives, as elucidated by DAD-UV spectra with comparisons to those of commercial standards. A Spanish high-oleic peanut possessed the greatest naturally-occurring level of p-coumaric acid and its derivatives, followed by a high-oleic Runner, a normal Runner, and a Virginia peanut. Upon thermal processing, p-coumaric acid was liberated at the expense of its derivatives according to the relationship: oil roasting > dry roasting > raw. A high-oleic Runner exhibited the greatest increase (～785%) in free p-coumaric acid levels after oil roasting. For many of the samples from the 2007 crop, processing increased the TPC and antioxidant capacities in the order of raw < dry roast < oil roast, but results were cultivar dependent. Oil-roasted peanuts were more effective at scavenging O₂ ^●- than their dry-roasted counterparts, as determined by a photochemiluminescence assay. Overall findings indicate that although thermal processing altered the composition of peanut kernel antioxidants, TPC values and radical-scavenging activities are preserved. Depending on peanut type, cultivar, and harvest date, enhanced antioxidant capacities can result.     

Major components of Spanish cultivated Artemisia absinthium populations: Antifeedant, antiparasitic, and antioxidant effects

The objective of this study was the valorization of Spanish Artemisia absinthium populations from Teruel (Aragón) and Sierra Nevada (Granada). These populations were experimentally cultivated in the field and under controlled conditions. Three major components were isolated from a two year-old population obtained from the Teruel population cultivated in Ejea-Zaragoza in 2003, and identified by NMR experiments as the sequiterpene lactone hydroxypelenolide (I) and the flavones artemetin (II) and casticin (III). The I-III content of the plant extracts was analyzed by HPLC-DAD. The insect antifeedant properties of plant extracts from different years and crops were tested against Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi. Additionally we studied their antioxidant, phytotoxic and antiparasitic effects.     

Phytotoxicity of Salvia spp. exudates

A study on thirteen Salvia species about the phytotoxicity of their aerial part exudates is reported. The selected species were: Salvia namaensis Schinz (1), Salvia fallax Fernald (2), Salvia disermas L. (3), Salvia chamaedryoides Cav. (4), Salvia confertiflora Pohl. (5), S. x jamensis J.Compton (6), Salvia buchananii Hedge (7), S. wagneriana Polak (8), Salvia scabra Linn.fil. (9), Salvia miniata Fernald (10), Salvia cacaliaefolia Benth.(11), Salvia adenophora Fernald (12), Salvia rutilans Carrière (13). For each species the inhibitory potential against Papaver rhoeas L. and Avena sativa L. was evidenced by dose-response studies and growth experiments performed both in Petri dish and in pot and also evaluated by means of germination indices and growth parameters. New indices useful for describing the phytotoxic response by a reduced number of testing solutions are proposed. Principal Component Analysis (PCA) of the germination data revealed that the exudate concentrations most significant in explaining the data variability were 1 and 2 μg/mL in Petri dish and 10 and 20 μg/mL in pot experiments. Root length and seedling weight were more important with respect to the other growth parameters.     

Synthesis of a novel flame retardant containing phosphorus-nitrogen and its comparison for cotton fabric

A new charring agent, a derivative of cyanuric chloride, mono-substituted, dimethyl (4,6-dichloro-1,3,5-triazin-2-yloxy)methylphosphonate (CN), was synthesized in good yield and characterized. Its flame retardant and thermogravimetric properties were compared to those of the di-substituted compound, tetramethyl (6-chloro-1,3,5-triazine-2,4-diyl)bis(oxy)bis (methylene)diphosphonate (CN-1), which was prepared in previous work. All untreated fabric showed limiting oxygen index (LOI) values of about 18 vol% oxygen in nitrogen. Fabrics treated with CN at 5?C21 wt% add-ons had high LOI values of 30?C40 vol%, while fabrics treated with CN-1 at 5?C19 wt% add-ons had low to high LOI value of 20?C36 vol%. In 45° angle flammability tests, all treated fabrics with CN and CN-1 were passed and some fabrics were not igniting at all. Thermal degradation revealed that onset of degradation and the char yield of CN compound is higher than that of CN-1. Treated fabric with CN, 21 wt% add-on, had an onset of degradation of 240 °C, while fabric treated with CN-1, 19 wt% add-on displayed an onset of degradation of 230 °C. Despite the differences in onset temperature, the two samples provided almost the same char yield at 600 °C, 35 and 36 %. With Fourier transform infrared (FTIR), samples of treated/unburned and treated/burned of CN and CN-1 showed the same functional groups and revealed the disappearance of triazine group and P-O-methyl after burning. Additionally, scanning electron microscopy (SEM) showed that both CN and CN-1 acted as flame retardants by the same mechanism and characterized the surface morphology of the flame retardant treated twill fabrics.     

Thermo-Mechanical Characterization of a Thermoplastic Copolyetherester (TPC): Experimental Investigation

In this article, the thermo-mechanical characterization of poly(butylene terephthalate)/poly(tetramethylene oxide) (PBT/PTMO) is studied by thermal analysis, dynamic mechanical analysis, and uniaxial tensile tests. The results of poly(ether esters) show that the melting temperature is equal to T _m =193 °C, which is 31 °C, lower than that of the melting temperature of poly(butylene terephthalate) (PBT). Its glass transition temperature, T _g is equal to -61 °C, determined by DMA. The melting and cooling temperatures (T _m , T _c ) after aging at T₀+48 h and T₀+week are virtually unchanged. Moreover, the results of the tensile tests show that the effect of the low deformation rate reduces the friction resulting from the sliding mechanisms between the amorphous and crystalline parts.     

Bacterial wilt resistance in the progenies of the fusion hybrids between haploid of potato andSolanum commersonii

Bacterial wilt of potatoes, which used to be a widespread disease in tropics and subtropics, has become a threat to potato production in temperate region. The diploid species Solanum commersonii has several desirable characteristics including cold tolerance and resistance to several diseases. Selected somatic hybrids between S. tuberosum dihaploid and bacterial-wilt-resistant S. commersonii clones were cross pollinated with S. tuberosum cultivars for further selection of bacterial wilt resistance. The chromosome numbers of the fusion parents were confirmed as 24, and the three fusion hybrids crossed were all tetraploids. The chromosome number of 11 backcross 1 progenies (BC1) was 48 and that of the other six was close to the tetraploid number. Backcross 2 progenies (BC2) were obtained from only three of the 44 BC1 clones crossed. The S. commersonii parent clone, LZ3.2, was the most resistant to bacterial wilt among wild species clones tested. The first sexual progenies segregated for resistance, with one clone highly susceptible and four clones highly resistant. Three highly resistant BC1 clones, CT02-4, CT08-4, and CT10b-4, were backcrossed to cultivars. Two cross combinations produced mostly susceptible BC2 progenies; however seven clones were resistant or highly resistant for both race 1 and race 3. The highly resistant three clones, CT204-3, CT206-9 and CT206-10, were selected for the further testing as cultivars or breeding materials.     

Study on oil adsorption/desorption kinetics and polymer network parameters of poly(lauryl methacrylate-<Emphasis Type="Italic">co</Emphasis>-hydroxyethyl methacrylate)

In the present work, oil adsorption, desorption, and resorption of poly(lauryl methacrylate-co-hydroxyethyl methacrylate) P(LMA-co-HEMA) were evaluated with different oils by a gravimetric method. Adsorption kinetics were modeled using pseudo-first-order and pseudo-second-order equations. Polymer network parameters of P(LMA-co-HEMA) regarding average molecular weight (Mc) between two crosslink piontss can be calculated by oil absorbency at equilibrium (Q _e ), the solubility parameter (δ) and polymer-solvent interaction parameter (χ) with Flory-Huggins relation. The results showed pseudo-second-order model has a better fit to the oil adsorption kinetic data The desorption can be analyzed by fitting a prediction of exponential-like decay to the deswelling curves. A typical oil desorption exhibited two stages: a burst release driven by concentration gradient, and a slow release controlled by diffusion and the elastic recovery of polymer networks. For reusability, the resorption behavior of P(LMA-co-HEMA) was also investigated. It was worth noting that oil resorption was faster than the first adsorption due to potential passages. Moreover, the adsorption capacity was not significantly changed after regeneration.     

Accounting for geographic heterogeneity of multifunctional rice policy in Taiwan

Through empirical simulations of the Taiwanese rice market, we estimate the effects of agricultural policies designed to ensure optimal levels of two multifunctional outputs, groundwater recharge, and methane emissions. Optimal policy instruments differ by region to reflect land quality and the conditions of the aquifers in major rice production regions. The effects on rice production, resource allocation, and returns to farm assets differ as well.

Thermal degradation behaviors and fire retardant properties of poly(1,3,4-oxadiazole)s (POD) and poly(m-phenylene isophthalamide) (PMIA) fibers

Thermal degradation behaviors and fire retardant properties of poly(1,3,4-oxadiazole)s (POD) and poly(m-phenylene isophthalamide) (PMIA) fibers were investigated. The thermal gravimetric analysis (TGA) demonstrated that POD exhibited higher onset thermal degradation temperature (T_onset) than PMIA, exceeding nearly 80 °C. The thermal degradation kinetics, evaluated by the modified Coats-Redfern method, displayed that the apparent activation energy (E_a) of POD and PMIA fibers was similar when the conversion rate (α) ranges from 0.2 to 0.5, while with the α from 0.6 to 0.8, the E_a of POD was significantly lower than that of PMIA. The fire retardant performance of POD and PMIA fibers were evaluated by cone calorimeter under heat fluxes of 35, 50 and 75 kW/m², during which the temperature of the fibers were monitored by a thermocouple. Surprisingly, POD fibers showed inferior fire retardant performance in comparison with PMIA, with lower time to ignition (TTI) and higher peak heat release rate (PHRR). The origin of the different fire retardant properties of both fibers was revealed by analyzing the residual chars and gaseous products during thermal pyrolysis. The morphology confirmed that stable and compact chars can be formed in PMIA. In addition, the Fourier Transform Infrared Spectroscopy (FTIR) characterization of the residual char revealed that POD can form carbonaceous chars at the heat flux of 50 kW/m², while the heat flux of PMIA was 75 kW/m². The pyrolysis products characterized by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) indicated that POD can be pyrolyzed completely at 600 °C, while the temperature of PMIA was 700 °C.     

Manufacture and performance of O-carboxymethyl chitosan sodium salt/cellulose fibers in N-methylmorpholine-N-oxide system

A series of O-carboxymethyl chitosan sodium salt (NaCMCh) with different degree of substitution (DS) of -CH₂COONa agent were successfully prepared by altering the reaction temperature and time. Both fourier transform infrared spectroscopy (FTIR) and ¹³C-Nuclear Magnetic Resonance (¹³C-NMR) were used to study the structure of NaCMCh. And the impact of DS on the antibacterial activity of NaCMCh was investigated. Then, the NaCMCh with optimal antibacterial activity was selected to prepare NaCMCh/cellulose fibers in N-methylmorpholine-N-oxide (NMMO) system. The structure, crystallization behavior, thermal property and morphology of obtained fibers were carefully studied with FTIR, Wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), thermal gravimetric (TG) and scanning electron microscope (SEM), respectively. Meanwhile, the antibacterial activity as well as mechanical properties of resultant fibers was also investigated. The results demonstrated that the fibers had strong antibacterial activity against Escherichia coli (E. coli), acceptable mechanical properties and good water retention.     

Quantification of fructan concentration in grasses using NIR spectroscopy and PLSR

Near-infrared reflectance (NIR) spectroscopy combined with chemometrics was used to quantify fructan concentration in samples from seven grass species. Savitzky–Golay first derivative with filter width 7 and polynomial order 2 with mean centering was applied as a spectral pre-treatment method to remove unimportant baseline signals. In order to model the NIR spectroscopy data the partial least squares regression (PLSR) approach was used on the full spectra. Variable selection based on PLSR by jack-knifing within a cross-model validation (CMV) framework was applied in order to remove non-relevant spectral regions. PLSR was also used to model fructan concentrations from an augmented matrix [X|G], where X is spectra and G is correlation matrix of band specific information and X, in order to integrate the chemical band information in regression models. The present analysis showed that rapid quantification of fructans by NIR spectroscopy is possible and that jack-knifing PLSR within a CMV framework is an effective way to eliminate the wavelengths of no interest. Jack-knifing PLSR did not improve the predictive ability because the root mean square error of prediction (RMSEP) increased (1.37) compared to the full model (1.26). This was possibly due to signals from carbohydrates, which could act as cofactor in the prediction of fructans. However, jack-knifing PLSR within a CMV framework simplified the interpretation of the regression model with r² = 0.90 and RMSEP = 1.37.     

Synthesis and cyanide anion recognition of a new displacement fluorescence chemosensor based on two-branched aurone

A new fluorescence turn-on chemosensor based on two dipyridylamine groups substituted aurone moiety, 4’-2,2’-dipyridylamine-3-2,2’-dipyridylamine aurone (1), was synthesized. The recognition properties of the compound for cyanide anions and copper ions were investigated. Yellow fluorescence of the compound is almost quenched completely because of the complexation between the compound and copper ions. After the subsequent addition of cyanide anions, fluorescence spectrum is recovered to the original status of the compound owing to the strong bonding ability between cyanide anions and copper ions and the removal of copper ions from the complexes. The recognition also can be observed by naked eye. The compound exhibits a good reversibility and can be used repeatedly to recognize cyanide anions for several times.     

Synthesis and characterization of new polyamides containing symmetrical and unsymmetrical thiadiazole rings

Diamino derivatives of thiadiazole namely, 2,5-diamino-1,3,4-thiadiazole and 3,5-diamino-1,2,4-thiadiazole were synthesized and characterized. Polyamides were synthesized by condensation of the two diamino derivatives with diacide chlorides. The structures of polyamides were verified by elemental analysis, FTIR, ¹H-NMR, ¹³C-NMR and mass spectroscopy. The polyamides possess good solubility in aprotic organic solvents such as DMF, DMAC, DMSO and NMP at room temperature. Intrinsic viscosity measurements indicate that the polyamides synthesized have moderate molecular weights. The thermal stability of these polyamides in nitrogen atmosphere is relatively good, especially for those polyamides containing phenylene ring in the backbone. Compared to the structurally related Kevlar aramide, using 2,5-diamino-1,3,4-thiadiazole and 3,5-diamino-1,2,4-thiadiazole instead of p-phenylene diamine results in reducing the melting points of polyamides to below 350 °C.     

Colorimetric detection of transition metal ions with azopyridine-based probing molecule in aqueous solution and in PMMA film

We report on an azopyridine derivative for probing transition metal ions and fabrication of its films. The probe, AP, showed a sensitive absorption change toward transition metal ions, especially cobalt ion, even at the concentration of ppm range, accompanied by yellow-to-red color transition with noticeable isosbestic point. In addition, the AP-containing PMMA film with high transparency can be fabricated by spin-casting without any aggregation of AP. The film with PMMA matrix shows good sensitivity toward cobalt ion similar to the case in the solution with a feature of metallochromic transition.     

Antibacterial Bilayered Skin Patches Made of HPMA and Quaternary Poly(4-vinyl pyridine)

This study aimed to produce poly(4-vinyl pyridine) and hydroxypropyl methacrylamide (HPMA)-based bilayer wound dressings materials enhancing healing mechanism for the wounds which have self-healing problem and high infection risk. These materials were designed to protect wound from secondary traumas caused microorganism invasion and do not have toxic substance release problem. Synthesis of quaternary poly(4-vinyl pyridine) (poly(Q4-VP)) which is the antibacterial layer of wound dressing material was carried out in two stages. At first stage, poly(4-vinyl pyridine) polymer was synthesized from 4-vinyl pyridine monomer by free radical polymerization. Then, poly(Q4-VP) was synthesized from poly(4-VP) by alkylation reaction with 6-bromocaproic acid. Resulted polymer was structurally characterized by FT-IR. The macroporous spongy structure, as the lower layer of wound dressing material, was prepared by cryogelation of HPMA. Then, the antibacterial polymer was electrospun onto the cryogel structure and bilayered material was obtained. Cryogel structure, fiber morphology and layer integration was examined by SEM. In order to enhance wound healing process, ascorbic acid (vitamin C) was loaded to cryogel layer and release was followed by spectrophotometrically. The antimicrobial properties of the materials were examined against Escherichia coli, Staphylococcus aureus and Candida albicans, respectively. According to the results, bilayered, antibacterial and antifungal against Staphylococcus aureus and Candida albicans, temporary wound dressings which can stimulate wound healing and have high swelling capacity were obtained successfully.