Fractionated Lignosulfonates for Laccase-Catalyzed Oxygen-Scavenging Films and Coatings

Lignin derivatives have potential as antioxidants in advanced packaging materials through their ability to scavenge oxygen in reactions catalyzed by phenol-oxidizing enzymes, such as laccase. The effects of size fractionation of lignosulfonates on laccase-catalyzed reactions were investigated in experiments with aqueous solutions, films, and coated paperboard. Four industrial lignosulfonate preparations were compared: Feed (unfractionated), Prod (5–60 kDa enriched), Conc (≥60 kDa enriched), and Perm (≤60 kDa enriched). Extraction of lignosulfonates from films showed that the enzymic reaction increased the average molecular weight from <10,000 to up to 66,000. The enzymatic reaction resulted in an increase in the water contact angle of the films from the range 25–49° to 56–81°. The four preparations showed relatively small differences with regard to their ability to scavenge oxygen in aqueous solution and in experiments with coated paperboards in sealed chambers. Coatings with lignosulfonates where the contents of low-molecular weight material had been reduced (i.e., Prod and Conc) showed improved water resistance after the enzymic reaction. Thus, in both aqueous and solid media, fractionation of lignosulfonates had little effect on oxygen scavenging, but fractionation was beneficial for other reasons, such as improved cross-linking resulting in higher molecular weight and superior water resistance.     

Impact of Metallic Nanoparticles on In Vitro Culture,Phenolic Profile and Biological Activity of Two Mediterranean Lamiaceae Species: Lavandula viridis L’Hér and Thymus lotocephalus G. López and R. Morales

Nanoparticles (NPs) recently emerged as new chemical elicitors acting as signaling agents affecting several processes in plant metabolism. The aim of this work was to investigate the impact of the addition of copper oxide (CuO), zinc oxide (ZnO) and iron oxide (Fe₃O₄) NPs (<100 nm) at different concentrations (1, 5 and 10 mg/L) to the culture media on several morphological, physiological and -biochemical parameters of in vitro shoot cultures of Lavandula viridis L’Hér and Thymus lotocephalus G. López and R. Morales (Lamiaceae), as well as on phenolic profile and bioactivity (antioxidant and enzyme inhibition capacities). Although some decreases in shoot number and length were observed in response to NPs, biomass production was not affected or was improved in both species. Most NPs treatments decreased total chlorophyll and carotenoid contents and increased malondialdehyde levels, an indicator of lipid peroxidation, in both species. HPLC-HR-MS analysis led to the identification of thirteen and twelve phenolic compounds, respectively, in L. viridis and T. lotocephalus extracts, being rosmarinic acid the major compound found in all the extracts. ZnO and Fe₃O₄ NPs induced an increase in total phenolic and rosmarinic acid contents in T. lotocephalus extracts. Additionally, some NPs treatments also increased antioxidant activity in extracts from this species and the opposite was observed for L. viridis. The capacity of the extracts to inhibit tyrosinase, acetylcholinesterase and butyrylcholinesterase enzymes was not considerably affected. Overall, NPs had a significant impact on different parameters of L. viridis and T. lotocephalus in vitro shoot cultures, although the results varied with the species and NPs type.     

Structure and Photochemical Behavior of the Cyclodextrin Inclusion Complexes of the Benzoylthiophene‐Derived Drugs Tiaprofenic Acid (=5‐Benzoyl‐α‐methylthiophene‐2‐acetic Acid) and Suprofen (=α‐Methyl‐4‐(2‐thienylcarbonyl)benzeneacetic Acid)

The effect of β‐cyclodextrin (β‐CD) on the excited‐state reactivity of the two benzoylthiophene derivatives, tiaprofenic acid (TPA; 2 ) and suprofen (SPF; 3 ) in their carboxylate forms is studied. The presence of β‐cyclodextrin does not affect the nature of the photoproduced transients and the photoproducts, but increases the photodegradation quantum yields of both drugs. The efficiency of the photodecarboxylation process is enhanced. This effect is rationalized in the light of the inclusion of 2 and 3 in the β‐CD cavity, affecting the energy of the lowest excited states of the drugs. The structure of the complexes is determined by induced circular dichroism, and molecular‐mechanics and dynamic Monte Carlo calculations. The photoreactivity of the decarboxylated photoproduct 7 of tiaprofenic acid ( 2 ) in presence of β‐CD is also examined.     

Headspace Sorptive Extraction (HSSE) in the Headspace Analysis of Aromatic and Medicinal Plants

A new sampling technique, Headspace Sorptive Extraction (HSSE), is here applied for the first time to the headspace sampling of medicinal and aromatic plants. The analyte partition coefficient between HSSE‐PDMS stir bar and sample headspace (K₁), the concentration factor (CF), the reproducibility, and the minimum recoverable amount were determined by analyzing standard solution of high volatility C₅–C₇ compounds with different polarities and structures (cyclohexane, propyl acetate, hexanal, 1‐hexen‐3‐ol, isoamyl acetate, and 2‐heptanol). Four aromatic and medicinal plants, viz. rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.), thyme (Thymus vulgaris L.), and valerian (Valeriana officinalis L.) were analyzed by HSSE‐GC with PDMS stir bars, and their concentration capacity was compared with those of S‐HS and HS‐SPME with different fibers. HSSE showed very high concentration capability with both standard and real sample components.     

Syntheses,Structures, and Properties of New Quaternary Gold-Chalcogenides: K2Au2Ge2S6, K2Au2Sn2Se6, and Cs2Au2SnS4

The new compounds K₂Au₂Ge₂S₆ ( 1 ), K₂Au₂Sn₂Se₆ ( 2 ), and Cs₂Au₂SnS₄ ( 3 ) have been synthesized through direct reaction of the elements with a molten polyalkalithiogermanate(stannate) flux at 650, 550, and 400 °C, respectively. Their crystal structures have been determined by single crystal X-ray diffraction techniques. 1 crystallizes in the monoclinic space group P2₁/n with a = 10.633(2) Å, b = 11.127(2) Å, c = 11.303(2) Å, β = 115,37(3)°, V = 1208,2(3) ų and Z = 4, final R(Rw) = 0.045(0.106). 2 crystallizes in the tetragonal space group P4/mcc with a = 8.251(1) Å, c = 19.961(4) Å, V = 1358,9(4) ų and Z = 4, final R(Rw) = 0.040(0.076). 3 crystallizes in the orthorhombic space group Fddd with a = 6.143(1) Å, b = 14.296(3) Å, c = 24.578(5) Å, V = 2158.4(7) ų and Z = 4, final R(Rw) = 0.039(0.095). The structures of 1 , 2 , and 3 consist of infinite, one-dimensional anionic chains containing X₂Q₆^4– units linked by Au⁺ ions and charge balancing K⁺/Cs⁺ ions situated between the chains. All compounds were investigated with differential thermal analysis, FT-IR, and solid state UV/VIS diffuse reflectance spectroscopy.     

Capillary GC Determination of Amines in Aqueous Samples Using Sorptive Preconcentration on Polydimethylsiloxane and Polyacrylate Phases

The use of sorptive extraction/thermal desorption (SE/TD) for the enrichment of amines from aqueous samples was investigated. The amines were derivatized in situ in the water sample by pentafluorobenzoyl chloride and subsequently enriched onto the SE cartridge. Two SE/TD cartridges were used, a commercially available polydimethylsiloxane (PDMS) packed cartridge and a similar cartridge prepared with newly synthesized poly(butyl acrylate) (PBA). Blank profiles of PBA were not as good as those obtained from the PDMS phase. A complex chromatogram was obtained using mass spectrometric detection. Fortunately, the use of a nitrogen-phosphorus detector (NPD) resulted in clean blanks. The PBA phase showed superior performance for the enrichment of the polar amine derivatives from water samples compared to the PDMS material. Using a CGC-NPD set-up and only 1 mL samples, detection limits are in the sub-ppb range.     

Analysis of the Triglycerides and the Free and Derivatized Fatty Acids in Fish Oil by Capillary Electrochromatography

Capillary ElectroChromatography (CEC) on a fused silica capillary column (40 cm L × 100 μm i.d.) packed with 3 μm octadecylsilica (ODS) was evaluated for the analysis of the triglycerides and their fatty acids in fish oils, and more especially in the oil of Moroccan Sardinia pilchardus. The very high complexity of the lipids in fish oil is well illustrated by CEC with a nonaqueous mobile phase consisting of acetonitrile/isopropanol/n-hexane in the ratio 57/38/5 to which 50 mM ammonium acetate has been added. In order to unravel the complexity, the oil was hydrolyzed and the free fatty acids (FFAs), the methyl esters (FAMEs), and the phenacyl esters (FAPEs) were analyzed by CEC on the same column used for the analysis of the triglycerides. Isocratic elution was achieved with the mobile phase acetonitrile/50 mM MES pH 6 in ratio 9/1. The migration characteristics of FFAs, FAMEs, and FAPEs are compared. The analysis of FAPE derivatives has the advantage that quantification applying UV detection is possible and moreover that the number of double bonds in the fatty acid chains can be elucidated by measuring the UV abundance ratio 240/210 nm.