查看更多>>摘要：? 2022The effect of steam explosion treatment (SE) on the appearance and water permeability of solid beech, poplar, and spruce wood was investigated. Wooden test specimens were steam blasted after water or acid impregnation at 10 ~ 16 bar for 5 ~ 15 min, and their chemical composition was determined by chromatographic analysis after hydrolysis and infrared spectroscopy. Macro/micro cracks with shrinkage and reduced sphericity after drying were observed by scanning electron microscopy. Darker color and more severe changes in colorimetric parameters were measured spectrophotometrically for SE treated samples, especially under acidic conditions or higher severity factors (SF). To some extent, the physicochemical and permeability properties of SE treated wood samples could be simulated by considering the correlations of the different factors. No significant deterioration in chemical content, longitudinal compressive modulus of elasticity (MOE//) and modulus of rupture (MOR//) was observed in SE specimens treated with water. Higher permeability was obtained under a mild condition of 180 °C-5 min for poplar and a higher SF condition for beech and spruce. Therefore, SE could be an efficient method for modifying solid wood to improve its permeability and functionality.
查看更多>>摘要：? 2022Genetic progress as the mean yield increase within self (S1), and open-pollinated (OP) plants from eight bitter fennel populations were studied using the best nine full-sib (S1) and their corresponding nine half-sib (OP) plants from each population for agro-morphological traits and essential oil characteristics during two years. The average of S1 populations showed depression for all studied characteristics particularly the number of effective umbels per plant (NEUP) as the main yield component. However, some of the best S1 progenies performed well with stable and comparable yield to OP progenies. In addition, self-pollination interestingly increased the percentage of four major compounds including α-pinene, limonene, fenchone, and estragole in the essential oil (EO). In most populations, α-pinene, limonene, and fenchone were 2–4 times higher in selected S1 genotypes compared to OP counterparts. An inbred plant with more than 10-fold higher estragole content than the normal range was also identified among the selected genotypes. Conversely, the percentage of (E)-anethole decreased due to self-pollination in all selected plants in both years. Therefore, it may be concluded that although self-pollination has deleterious effects on the population's general fitness, it may lead to improvement in the composition of EO in high-performing selected genotypes of bitter fennel for specific purposes and further utilization in pharmaceutical industries.
查看更多>>摘要：? 2022 Elsevier B.V.The main aim of the research was to evaluate changes in contents of essential oils and pigments in Norway spruce needles as affected by short-term storage under different conditions as well as to assess the potential resources of winter-harvested foliage obtainable from by-products of forest felling as a natural source of these bioactives. One- and two-year-old needles were taken for the analyses fresh (control) and after five-week storage at three different conditions: at 4 °C in fridge, at ?24 °C in freezer and in the forest of their origin. Essential oils were isolated from needles by hydrodistillation and analysed by gas chromatography-mass spectrometry. Analyses of chlorophylls and carotenoids were performed spectrophotometrically. The study showed that none of the tested storage conditions of P. abies needles had significant influence on the total amounts of essential oils in them varying from 0.16% to 0.20% per dry matter (v/w) in two- and one-year-old needles, respectively. Bornyl acetate was the main compound identified in the essential oils amounting to 14.47–40.04%. The mean total contents of chlorophylls amounted to 1.10 mg/g in one-year-old needles and to 1.28 mg/g in two-year-old ones measured in fresh weight. Statistically significant differences were established in the levels of all the pigments analysed between fresh material, and stored under controlled, ?24 °C and 4 °C, conditions both of 1-year-old and 2-year-old needles. The highest contents of the pigments were obtained after the storage at 4 °C as well as under the natural forest condition. Based on the above data and the national forestry statistics, potential yields of essential oils (6.45 kg), total chlorophylls (9.27 kg) and total carotenoids (1.32 kg) were assessed per hectare of a mature sprucewood stand in Lithuania.
查看更多>>摘要：? 2022 Elsevier B.V.Silybum marianum (L.) Gaertn. has been recently valorised as oilseed crop for its productivity and for the chemical composition of its oil. However, a high oleic acid oil (HO) line, which would be useful for cooking but also for biodiesel production and other industrial applications, was not found in its natural germplasm. To address this issue, an ethyl methanesulfonate-induced mutagenesis programme was implemented, and the screening of the mutagenized population led to the identification of a HO mutant line with a much higher oleic acid oil content with respect to the wild type (WT). Since Fatty Acid Desaturase 2 (FAD2) genes are responsible for the determination of oleic acid levels in vegetable oils of other species, the present research focused on the characterization of this gene family as the possible target of mutagenesis. An extremely large multigene family consisting of twenty-one unique and complete FAD2 orthologous sequences was identified in S. marianum. Sequence comparison of all the SmFAD2 genes between the WT and HO genotypes revealed a single nucleotide polymorphism (SNP) in SmFAD2–1, the only fruit-specific gene, resulting in a non-synonymous substitution in the predicted protein in the high oleic genotype. The SNP and the HO phenotype were found to perfectly cosegregate in the F2 progeny derived from the HO x WT crosses, suggesting the direct implication of this gene in the determination of oleic and linoleic acid fruit content in S. marianum fruits.
查看更多>>摘要：? 2022 Elsevier B.V.This study aimed at investigating the insecticidal, repellent, genotoxic, and cytotoxic effects of Colocasia esculenta leaf extract (CELE). The crude extract obtained by maceration followed by fractionation was screened for the presence of phytochemicals.Insecticidal and repellent testings against colonies of Sitophilus zeamais maintained on Tropical zea Nigerian population B (TZB) Gusau POOL16 insect-free maize variety using a residual exposure method were evaluated. Brine shrimp lethality and genotoxicity assays were carried out against Artemia salina and Allium cepa respectively. Phytoconstituents were identified using GC-MS. Qualitative analyses revealed the presence of various phytochemicals. Highest total phenolic (30.16 ± 0.34 mg GAE/g), tannin (4.37 ± 0.04 mg GAE/g), flavonoid (5.10 ± 0.18 mg QUE/g) and alkaloid (11.37 ± 0.26 APE/g) contents were obtained in the ethyl acetate fraction (EAF) followed by an insecticidal LC50 value of 6.20 ± 0.57 μg/ml and a repellency rating of 6.6 ± 0.50 after 24 h exposure period making it the most biotoxic. The repellency rating was 5.5 ± 0.1, whereas the mitotic index was 16.37 with a significant (p < 0.05) chromosomal aberration value of 6.42%. The GC-MS of the EAF identified 25 compounds such as bicycle (3.1.1)heptane-2,6,6-trimethyl (17.23%), octadecanoic acid (15.10%), hexadecenoic acid ethylester (15.10%), 9,12,15-Octadecatrienoic acid- (Z,Z,Z)- (14.09%) and ethyl-9,12,15-octadecatrienoate (14.09%). The study concluded that the potent fraction of CELE possessed bioactive phytoconstituents suggesting its use as natural alternative control agents in the integrated pest management of staple.
查看更多>>摘要：? 2022 The AuthorsGuayule (Parthenium argentatum, A. Gray) is a promising alternative source to natural rubber from Hevea brasiliensis L. Recently, another important fraction of its composition, the resin, has been the focus of many studies due to its promising commercial applicability. In the resin extract there are guayulins (A, B, C and D), belonging to the sesquiterpene family, which are usually analyzed by HPLC-DAD and, lately, with other labor-intensive analytical techniques. Near infrared spectroscopy (NIR) has been successfully used in fresh guayule and dry biomass to assess moisture, and total rubber and resin content. The purpose of the present study is to estimate, for the first time ever, the detailed guayulin content in guayule dry stems using NIR spectroscopy. So, a set of 144 samples were analyzed by a Perkin Elmer Spectrum One FT-NIR equipment coupled with a near infrared reflectance accessory (NIRA). In addition, guayulins A and B standards, isolated in the lab, were scanned to generate the best partial least squares regression (PLSR) model. The best correlative PLSR models for resin, rubber and guayulins were developed within the range of 1100–2500 nm, showing an excellent calibration correlation (r2c = 0.92–1.00) and cross validation (r2cv = 0.87–0.92). The residual predicative deviation (RPD) was above 3 in the case of resin, rubber and guayulins A, B and D; while in guayulin C was 2.8. These high RPD values demonstrated a good prediction power of the model. In conclusion, the use of NIR spectroscopy for the estimation of resin and guayulin content in ground guayule stems is an excellent option for the routine analysis instead of time-consuming and labor-intensive traditional techniques.
查看更多>>摘要：? 2022 Elsevier B.V.Wood vinegar is a complex mixture of organic compounds. QAMS is a relatively simple and cost-effective method which is used widely in recent years. In this study, quantitative analysis of multi-components by single-marker (QAMS) was applied to quantify the main volatile chemical components in wood vinegar for the first time. Using acetic acid as an internal reference compound, the relative correction factors of a further 19 chemical volatile components were obtained. 20 wood vinegar prepared from different lignocellulosic biomass, and at different pyrolysis temperatures, were analyzed by QAMS and the data compared with those obtained using an internal standard (phenethyl acetate) method. The results showed that the precision and repeatability of the QAMS method were good, and the responses obtained for each compound using GC/MS were linear over the corresponding concentration range (R2 ≥ 0.999). The average spike recoveries of 20 volatile compounds from wood vinegar ranged from 92.65% to 105.93% (RSD ＜ 7%, n = 6). There were no significant differences (P > 0.05) in the results obtained from the analysis of three batches of wood vinegar samples (RSD < 2%) using both methods. The volatile composition of samples obtained from wood vinegar prepared from the pyrolysis of different materials and at different temperatures were significantly different. The successful application of QAMS to the quantitative analysis of the composition of wood vinegar not only may provide a theoretical reference for further developments in the production, pyrolysis conditions, and modes of action for wood vinegar, but also provides ideas for the application of QAMS in other fields.
查看更多>>摘要：? 2022 Elsevier B.V.Trigonella plants are semiarid crops grown all over the planet where their seeds and leaves are commonly utilized in cosmetic, medical and therapeutic purposes. Despite substantial research on the seeds, comprehensive study of Trigonella leaves extracts has not been documented. In this work, chemical profiling of T. foenum-graecum, T. maritima, T. hamosa and T. stellata leaves extracts using UHPLC-QqQ-MS, where the relationship between the bioactive elements of the leaves and their in-vitro α-amylase and α-glycosidase inhibitory potential was investigated through employment of integrated metabolomics and chemometric analyses. 50 compounds were identified with saponins, flavonoids and pterocarpans being the most abundant classes in all extracts while amino acids accumulated exclusively in T. foenum-graecum. Orthogonal projection to latent structure discriminant analysis models coefficients plots revealed hamoside B, sarsaponin, and trigocoumarin were correlated positively to T. hamosa leaves while, quercetin, quercetin hexoside, and isoschaftoside, were correlated to T. stellata. Oxovaleric acid, trigraecum, and trigoneoside were correlated positively to T. maritima class. Further, the amino acids hyroxyisoleucine and ketoleucine, and the alkaloid trigonelline correlated strongly to T. foenum-graecum. The recognition of inhibitory α-amylase and α-glycosidase discriminatory metabolites was investigated through OPLS discriminatory model construction along with correlation coefficients analysis which depicted that 4-hydroxyisoleucine, trigonelline and hamoside B were the main constituents positively correlated to α-amylase inhibitory acivity while quecetin, quercetin hexoside and isoschaftoside possessed the highest positive correlation to α-glycosidase inhibitory effect. This research lays the groundwork for future research into the antidiabetic potential of the leaves of different Trigonella species which were revealed to be valuable sources of bioactive chemical compounds.
查看更多>>摘要：? 2022 Elsevier B.V.The continuous cropping of poplar plantations will accumulate allelochemicals such as para-hydroxybenzoic acid (pHBA) in the soil, which restricts the growth and biomass of poplar. Mitogen-activated protein kinase (MAPK) cascades are widely involved in environmental stress responses in plants. However, little is known about the role of MAPK cascade genes in the response to pHBA stress until now. Here, a novel group C MAPK gene, PeMPK7, from Populus × euramericana was characterized. The PeMPK7 transcript was induced by exogenous pHBA and H2O2, and its induced transcription by pHBA was blocked by the reactive oxygen species (ROS) manipulators. Overexpression of PeMPK7 in poplar alleviated the phenotypic injury induced by pHBA stress, reduced H2O2 accumulation and alleviated the oxidative injury in leaf cells. The expression of the encoding genes and enzyme activity of the antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) were upregulated in transgenic poplars under pHBA conditions, which will help to remove excessive ROS. In addition, the enhanced soluble sugar and free proline in transgenic poplar seedlings may contribute to maintaining osmotic homeostasis under pHBA stress. Furthermore, the interaction between PeMPKK3 and PeMPK7 was confirmed. A schematic model was proposed to show the regulatory mechanism of PeMPK7 in response to pHBA stress.
查看更多>>摘要：? 2022 Elsevier B.V.Lignin is the second most abundant component of lignocellulosic biomass after cellulose. This aromatic polymer has an immense potential for applications in composite materials, organic synthesis and pharmaceutical industries. In this study, different types of lignin (Kraft and three organosolv lignins from different processes) were characterized and incorporated into a pressure sensitive adhesive (PSA) aqueous formulation based on polycarboxylate polyether (PCE), which was selected for its low ecotoxicity. All lignin samples were evaluated and compared using various characterization methods, such as GPC, 13C NMR and 31P NMR spectroscopy. Thermal properties were investigated using TGA and DSC techniques. Based on these analyses, organosolv lignin samples presented lower molecular weight (Mw), lower polydispersity and higher amounts of phenolic OH groups. Optimizing molecular weight and hydroxyl contents were found to be the main factors affecting PSA properties. One of our formulations (5-OL-B2), which incorporated the organosolv lignin of lowest molecular weight (Mw ≈ 1270 g/mol) and highest OH content (~7.08 mmolOH/glignin), leads to an adhesive performance similar to that the commercial PSA, such as low peel-off losses and lower distance traveled by the ball (higher tackiness).
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