Behavior of (–)-α-Bisabolol and (–)-α-Bisabololoxides A and B in Camomile Flower Extraction with Supercritical Carbon Dioxide

Abstract

A systematic study of the extraction behavior of selected components of camomile flowers in extraction with supercritical carbon dioxide was carried out. (–)-α-Bisabolol and its A and B oxides, which have a wide importance in pharmacology and standardization of camomile flower products, were selected. The dependence of the yield of selected components on the pressure and/or temperature of supercritical extraction was investigated. The results obtained were correlated.     

Unique bioactive molecule composition of sea buckthorn (Hippophae rhamnoides L.) oils obtained from the peel,pulp, and seeds via physical “solvent-free” approaches

Sea buckthorn (Hippophae rhamnoides L.) is a highly valuable plant with bioactive compounds widely used in food, medicinal, and pharmaceutical industry. During sea buckthorn berry processing into juice, byproducts from the juice, peels, and seeds are generated. Hence, in this study three types of oils (pulp, seed, and peel oil) were obtained via the use of physical “green” technologies. The pulp oil was obtained by a milk separator, while seed and peel oils were extracted by a cold-press. The extracted oils were then subjected to assays that determined their detailed profiles of triacylglycerols, fatty acids, tocopherols, tocotrienols, carotenoids, sterols, and phenolic compounds. The peel oil was a significantly richer source of bioactive compounds compared to both the pulp and seed oils. With respect to the lipid profile, the peel oil was similar compared to the pulp oil. The peel oil also had a slightly lower content of sterols in comparison to seed oil and was the only oil fraction that had considerable levels of squalene present. The concentration ranges of the minor molecules detected are as follows: 100.0–273.6, 427.4–575.0, 0–402.4, 0.9–72.0, 0.9–15.6 mg/100 g oil of tocochromanols, sterols, squalene, carotenoids, and flavonols, respectively.     

Palmitoleic Acid Enrichment of Seabuckthorn (Hippophaë rhamnoides L.) Pulp Oil by Crystallization Process

Abstract

Seabuckthorn pulp oil was fractionated using a crystallization process with acetone under controlled cooling rate of 0.25°C/min without agitation at different crystallization temperatures ranging from ? 15 to 15°C. The obtained liquid (LF) and solid (SF) fractions were analyzed for their fatty acid and triacylglycerol compositions and their melting profiles were characterized. Fractionation at ? 15°C yielded about 20% of LF where palmitoleic acid represented 53% of total lipids. The SF fraction was mainly rich in palmitic acid. LF were richer in triacylglycerol with acyl carbon numbers of 50 and 52 (C50 and C52) than SF, which contained a higher amount of C48. The melting curves of LF and SF showed multiple endothermic transitions.     

Supercritical fluid extraction of volatile oil from Lippia alba (Mill.) cultivated in Aragón (Spain)

The objective of this study is the supercritical extraction of the volatile oil from Lippia alba (Mill.) cultivated in Aragón. The influence of extraction pressure and temperature and cosolvent percentage on overall yield and volatile oil composition was studied. The supercritical extraction conditions were optimized using the 2007 crop; operating at 35.0 MPa, 40 °C and 5% of ethanol as cosolvent, 2009 and 2011 crops were also tested. Supercritical fluid extract compositions and overall yields were compared with the extracts obtained by conventional extraction techniques such as hydrodistillation (HD) and organic solvent extraction (OSE). Four terpenoids (linalool, 1,8-cineole, β-caryophyllene and β-caryophyllene oxide) were selected as target compounds and their content in the different extracts was monitored by gas chromatography. Linalool was selected as indicator of the plant adaptation to the commercial purposes. HD is the technique that provides the highest percentage of linalool in all the extracts, but showed always the lowest overall yields; whereas, SFE extracts provides a good balance between the overall yield and presence of the four target compounds.     

Crystallisation of Wild-Type and Variant Forms of a Recombinant Plant Enzyme ��-d-Glucan Glucohydrolase from Barley (Hordeum vulgare L.) and Preliminary X-ray Analysis

Wild-type and variant crystals of a recombinant enzyme β-d-glucan glucohydrolase from barley (Hordeum vulgare L.) were obtained by macroseeding and cross-seeding with microcrystals obtained from native plant protein. Crystals grew to dimensions of up to 500 × 250 × 375 μm at 277 K in the hanging-drops by vapour-diffusion. Further, the conditions are described that yielded the wild-type crystals with dimensions of 80 × 40 × 60 μm by self-nucleation vapour-diffusion in sitting-drops at 281 K. The wild-type and recombinant crystals prepared by seeding techniques achived full size within 5–14 days, while the wild-type crystals grown by self-nucleation appeared after 30 days and reached their maximum size after another two months. Both the wild-type and recombinant variant crystals, the latter altered in the key catalytic and substrate-binding residues Glu220, Trp434 and Arg158/Glu161 belonged to the P4₃2₁2 tetragonal space group, i.e., the space group of the native microcrystals was retained in the newly grown recombinant crystals. The crystals diffracted beyond 1.57–1.95 Å and the cell dimensions were between a = b = 99.2–100.8 Å and c = 183.2–183.6 Å. With one molecule in the asymmetric unit, the calculated Matthews coefficients were between 3.4–3.5 ų·Da⁻¹ and the solvent contents varied between 63.4% and 64.5%. The macroseeding and cross-seeding techniques are advantageous, where a limited amount of variant proteins precludes screening of crystallisation conditions, or where variant proteins could not be crystallized.     

Extraction of Lanthanides(III) from Aqueous Nitrate Media with Tetra‐(p‐tolyl)[(o‐Phenylene)Oxymethylene] Diphosphine Dioxide

A novel tridentate neutral organophosphorus compound, tetra‐(p‐tolyl)[(o‐phenylene)oxymethylene] diphosphine dioxide (I) has been synthesized and its extracting ability for microquantities of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y from HNO₃ and NH₄NO₃ aqueous solutions has been studied. The effect of HNO₃ concentration in the aqueous phase and that of the extractant concentration in the organic phase on the extraction of metal ions is considered. The stoichiometry of the extracted complexes and conditional extraction constants of Ln(III) have been determined. The extraction behavior of compound I is compared with that of the diglycolamide ligand TODGA. The potentialities of polymeric resin impregnated with compound I for the preconcentration of lanthanides(III) from nitric acid solutions are demonstrated.     

Carbon Dioxide Solubility Enhancement through Silicone Functionalization: “CO2-philic” Oligo(dimethylsiloxane)-substituted Diphosphonates∗

Abstract

Carbon dioxide has received significant attention as a potential environmentally benign medium to replace hazardous organic compounds, but is a relatively poor solvent. The addition of siloxane substituents provides an attractive and inexpensive means to solubilize a wide variety of compounds in CO₂. By synthesizing and testing a family of gem-diphosphonate ligands that have been rendered CO₂-philic by incorporation of a number of related, discrete dimethylsiloxane oligomers, we show that small variations in substituents have a significant effect on the CO₂-philicity of the ligand. To our knowledge, this is the first systematic study of the effect of siloxane substituent size, branching, and position on the affinity of a ligand for CO₂. In addition, we present a general approach to the preparation of novel gem-diphosphonate ligands.     

Preparation of High-Purity (–)-Borneol and Xanthoxylin from Leaves of Blumea balsamifera (L.) DC.

A novel and simple process for the preparative extraction, separation, and purification of high-purity (–)-borneol and xanthoxylin, synchronously, from the leaves of Blumea balsamifera (L.) DC was developed. Simultaneous distillation and extraction, silica gel column chromatography, and recrystallization were applied to the preparation. Two objective compounds with the purity of 98% were obtained, and the losses were minimal during the whole procedure. It is the first time that the preparation of high-purity (–)-borneol and xanthoxylin at the same time were achieved.     

Papain from papaya (Carica papaya L.) fruit and latex: Preliminary characterization in alcoholic–acidic buffer for wine application

Papain from ripe fruit and from papaya latex was characterised, in comparison with stem bromelain, under wine-like conditions, with the aim to evaluate their applicability for white wine stabilization.Papains proteolytic activity was investigated, in McIlvaine buffer toward different synthetic peptide substrates and Bz-Phe-Val-Arg-pNA appeared the most suitable one for detecting proteolytic effect at wine average minimum pH (3.2). Kinetic parameters estimated in McIlvaine (as reference) and in tartaric buffer (mimicking wine medium), indicated a good hydrolytic activity toward selected substrate, at wine average minimum pH value (3.2) in spite of ethanol presence, in both mediums. Papain from latex showed a significantly higher and stable catalytic activity respect to fruit papain and stem bromelain, retaining after 7 days, about 50% of its initial activity.     

Camelina (Camelina sativa L.) oil as a biofuels feedstock: Golden opportunity or false hope?

Camelina (Camelina sativa L.) is a promising sustainable alternative energy crop belonging to the Brassicaceae (mustard) family. Camelina has several favorable agronomic characteristics which give it potential to significantly enhance domestic biofuels production. With high seed oil content as well as high yield of oil per hectare, camelina can be efficiently processed into high quality renewable fuels such as biodiesel (fatty acid methyl esters) as well as renewable diesel and jet fuels using existing technologies. This review summarizes the attributes of camelina along with conversion of the lipid fraction into advanced renewable biofuels.     

In Situ Observation and Physical–Chemical Characteristics of Rambutan (Nephelium lappaceum L.) Kernel Olein Crystals Obtained from Acetone Fractionation

Hard fat stocks containing highly saturated fats are a necessary ingredient for fabrication of trans-free plastic fats. Crystal fractions obtained from the fractionation of fats naturally containing saturated fatty acids (SFA) may be a promising approach to produce the desired hard fat stocks. Influences of cooling rate (0.4, 2.0 and 10.0 °C·min⁻¹) and fractionation temperature (15 and 20 °C) on the formation of solid fat crystals of rambutan (Nephelium lappaceum L.) kernel olein (RKOle) during acetone fractionation were examined using in situ observation with polarized light microscopy (PLM). The resulting stable crystals were then separated and characterized by their iodine values, fatty acid compositions, crystal polymorphism, solid fat index, and melting behavior. PLM results showed that cooling rate affected crystal formation. Entrained oil on the surface and number of small crystals increased at higher cooling rates of RKOle. Stable crystals were obtained at a cooling rate of 2.0 °C·min⁻¹ and 6 hours, which had lower iodine value and contained more SFA with a higher amount of solid fat than incipient RKOle. Crystals fractionated at 20 °C were larger in size, fewer in number, and had less entrained oil compared to those fractionated at 15 °C. Their main polymorph was the β' form with a melting range comparable to common fully hydrogenated oils. Results suggested that RKOle crystals have potential for use as hard fat stocks for various purposes.     

2,2′-oxo-1,1′-azobenzene: microbial transformation of rye (Secale cereale L.) allelochemical in field soils byAcinetobacter calcoaceticus: III

Acinetobacter calcoaceticus, a gram-negative bacterium isolated from field soil, was found to be responsible for the biotransformation of 2(3H)-benzoxazolinone (BOA) to 2,2-oxo-1,1-azobenzene (AZOB). Experiments were conducted to evaluate the transformation of BOA to AZOB by this microbe in sterile and nonsterile soil. Transformation studies with soils inoculated withA. calcoaceticus indicated that the production of AZOB increased linearly with the concentration of BOA in sterile soil and showed a quadratic trend in nonsterile soils. This also indicated that all soil types studied for the transformation experiments might containA. calcoaceticus capable of the conversion of benzoxazolinones.     

2,2′-OXO-1,1′-azobenzene: Selective toxicity of rye (Secale cereale L.) allelochemicals to weed and crop species: II

Three allelochemicals from rye or its breakdown products were evaluated for activity on garden cress (Lepidum sativum L.), barnyardgrass [Echinochloa crus-galli (L.) Beauv.], cucumber (Cucumis sativus L.), and snap bean (Phaseolus vulgaris L.). 2,4-Dihydroxy-1,4(2H)-benzoxazin-3-one (DIBOA), 2(3H)-benzoxazolinone (BOA), and 2,2-oxo-1,1-azobenzene (AZOB) were all applied singly at 50, 100, and 200 ppm and in two- and three-way combinations each at 50 and 100 ppm. AZOB at 100 and 200 ppm produced 38–49% more inhibition than DIBOA, while combinations of BOA/ DIBOA, which contained AZOB at 100 ppm had 54–90% more inhibition when compared to DIBOA/BOA combinations. All combinations were slightly antagonistic to barnyardgrass, while several combinations caused a synergistic response to garden cress germination and growth. Cucumbers and snap beans exhibited both types of responses, depending on the allelochemical combination and application rate. The plant-produced benzoxazinones were more inhibitory to crops than weeds. Therefore, improved herbicidal selectivity would be expected if there were rapid transformation of the benzoxazinones to the microbially produced AZOB.     

Subcritical water extraction of phenolic compounds from pomegranate (Punica granatum L.) seed residues and investigation into their antioxidant activities with HPLC–ABTS+ assay

Subcritical water extraction (SWE) of phenolic compounds from pomegranate seed residues (PSR) was performed. Total phenolic content (TPC) and antioxidant capacities of the extracts obtained at different temperatures were determined, and the individual antioxidant capacities were evaluated by coupling high performance liquid chromatography with ABTS radical reaction system (HPLC–ABTS⁺). The results showed that the optimum extraction time was 30 min, solid to water ratio was 1:40, and the highest TPC was obtained at 220 °C. The effect of extraction temperature on TPC was significant (p < 0.05), and TPC ranged from 651.7 to 4854.7 (mg/100 g DW) between 100 °C and 220 °C. HPLC–ABTS⁺ profiles revealed that nine compounds had antioxidant activity. Furthermore, the formation of Maillard reaction products during SWE was investigated, and the content of 5-hydroxymethylfurfural (5-HMF) was determined. The comparative study indicated that SWE was a promising technique for preparation of PSR phenolics.     

Apparent Molar Volumes of N,N – Disubstituted Monoamides: A Convenient Tool to Interpret Iron(Iii) Extraction Profiles from Hydrochloric Acid Solutions

New iron(III) extraction data involving two N,N-disubstituted monoamides, N-ethyl-N-phenyloctanamide (EPHOA) and N-ethyl-N-cyclohexyloctanamide (ECHOA), from hydrochloric acid media, are presented and discussed. These, and earlier results obtained with other similar N,N-disubstituted monoamides, are interpreted in this work through their apparent molar volumes in 1,2-dichloroethane, and all the information is being used to screen for solute-solute and solute-diluent interactions. The results collected help to understand why N-cyclohexyl monoamides are generally more efficient than their N-phenyl analogues as liquid-liquid extractants for iron(III) from 3 to 5 M hydrochloric acid solutions, and clearly denote that N-phenyl monoamides are essentially monomeric whereas N-cyclohexyl monoamide derivatives have a tendency to aggregate in the organic solution.     

Combining osmotic–steam blanching with infrared–microwave–hot air drying: Production of dried lemon (Citrus limon L.) slices and enzyme inactivation

The different pretreatments were given to lemon slices to inactivate pectinesterase and peroxidase enzymes and to dry the product rapidly using infrared–microwave hot air combination. Osmotic pretreatment followed by 1-min steam blanching was found to reduce moisture in the product, increase solid content, and inactivate enzymes in lemon slices while maintaining negligible dry matter and juice sac loss. The infrared hot air was found effective in partial drying of pretreated lemon slices up to 1 hour without entering in drastic falling-rate period. Therefore, after 1?h microwave hot air was used to complete the drying process. The optimum infrared drying condition was found at 3000?W/m² radiation intensity, 90°C air temperature, 100?mm distance between lamp and product, and 1.5?m?s^?1 air velocity. In microwave finish drying, the power density of 0.30?W?g^?1, 89.9°C air temperature, and 0.5?m?s^?1 air velocity were found to result in the best product. The hybridization of osmotic–steam blanching and the two drying methods overcame the problems of browning, extended falling-rate periods, improper power distribution, and quality deterioration. Also, the higher values of moisture diffusivities were observed during hybrid drying.     

Highly unsaturated fatty acid synthesis in marine fish: Cloning, functional characterization, and nutritional regulation of fatty acyl Δ6 desaturase of Atlantic cod (Gadus morhua L.)

This study reports the cloning, functional characterization, tissue expression, and nutritional regulation of a Δ6 fatty acyl desaturase of Atlantic cod (Gadus morhua). PCR primers were designed based on the sequences of conserved motifs in available fish desaturases and used to isolate a cDNA fragment from cod liver, with full-length cDNA obtained by rapid amplification of cDNA ends. The cDNA for the putative desaturase was shown to comprise 1980 bp, including a 261-bp 5′-UTR, a 375-bp 3′-UTR, and an ORF of 1344 bp that specified a protein of 447 amino acids. The protein sequence included three histidine boxes, two transmembrane regions, and an N-terminal cytochrome b₅ domain containing the heme-binding motif HPGG, all characteristic of microsomal fatty acyl desaturases. The cDNA displayed Δ6 desaturase activity in a yeast expression system. Quantitative real-time PCR assay of gene expression in cod showed that the Δ6 desaturase gene was expressed highly in brain, to a slightly lesser extent in liver, kidney, intestine, red muscle, and gill, and at much lower levels in white muscle, spleen, and heart. The expression of the Δ6 desaturase gene did not appear to be under significant nutritional regulation, with levels in liver and intestine being barely altered in fish fed a vegetable oil blend, in comparison with levels in fish fed fish oil. This was reflected in enzyme activity, as hepatocytes or enterocytes showed very little highly unsaturated FA biosynthesis activity irrespective of diet. Further studies are required to determine why the Δ6 desaturase appears to be barely functional in cod under the conditions tested.     

Calcium phosphate and calcium carbonate mineralization of bioinspired hydrogels based on β-chitin isolated from biomineral of the common cuttlefish (<Emphasis Type="Italic">Sepia officinalis</Emphasis>, L.)

Chitin, a bioactive, antibacterial and biodegradable polymer is commonly utilized by diverse marine organisms as the main scaffold material during biomineralization. Due to its properties, chitin is also of interest as a component of organo-inorganic composites for diverse biomedical applications. In this study, chitinous fibers isolated from the cuttlebone of the common cuttlefish (Sepia officinalis, L.) are characterized and evaluated for use as an integral part of mineralized hydrogels for biomedical applications. Since marine organisms use calcium carbonates (CaCO₃), while vertebrates use calcium phosphates (CaP) as the main inorganic hard tissue components, and both minerals are used in hard tissue engineering, they were compared to determine which composite is potentially a better biomaterial. Hydrogel mineralization was conducted by subsequent dipping into cationic and anionic reactant solutions, resulting in the formation of a CaCO₃ or CaP coating that penetrated into the hydrogel. Obtained composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), rheology, swelling tests and simple compression. The results indicate that β-chitin can be used for the preparation of moldable hydrogels that are easily mineralized. Mineralized hydrogels have higher elasticity than non-mineralized ones while swelling is better if the extent of mineralization is lower. Further optimization of the hydrogels composition could improve their stress response and Young’s modulus, where the current hydrogel with a higher extent of CaP mineralization excels in comparison to all other investigated composites.