RESUMEN
To investigate the longitudinal variation patterns of sapwood, heartwood, bark and stem moisture content along the trunk of artificial Larix olgensis, we constructed mixed effect models of moisture content based on beta regression by combining the effects of sampling plot and sample trees. We used two sampling schemes to calibrate the model, without limiting the relative height (Scheme â ) and with a limiting height of less than 2 m (Scheme II). The results showed that sapwood and stem moisture content increased gradually along the trunk, heartwood moisture content decreased slightly and then increased along the trunk, and bark moisture content increased along the trunk and then levelled off before increasing. Relative height, height to crown base, stand area at breast height per hectare, age, and stand dominant height were main factors driving moisture content of L. olgensis. Scheme â showed the stable prediction accuracy when randomly sampling moisture content measurements from 2-3 discs to calibrate the model, with the mean absolute percentage error (MAPE) of up to 7.2% for stem moisture content (randomly selected 2 discs), and the MAPE of up to 7.4%, 10.5% and 10.5% for sapwood, heartwood and bark moisture content (randomly selected 3 discs), respectively. Scheme â ¡ was appropriate when sampling moisture content measurements from discs of 1.3 and 2 m height and the MAPE of sapwood, heartwood, bark and stem moisture content reached 7.8%, 11.0%, 10.4% and 7.1%, respectively. The prediction accuracies of all mixed effect beta regression models were better than the base model. The two-level mixed effect beta regression models, considering both plot effect and tree effect, would be suitable for predicting moisture content of each part of L. olgensis well.
Asunto(s)
Larix , Tallos de la Planta , Agua , Larix/crecimiento & desarrollo , Larix/química , Tallos de la Planta/química , Tallos de la Planta/crecimiento & desarrollo , Agua/análisis , Agua/química , Análisis de Regresión , Madera/química , Modelos Teóricos , PredicciónRESUMEN
Local plants can save natural resources and be used as a source of biologically active compounds, which can be high-quality, effective, and safe ingredients for pharmacological or chemical industries. Therefore, this study aimed to investigate the properties of two medicinal plants - the fine-scaled larch (Lárix Kaémpferi) and Siberian larch (Lárix Sibirica), which are growing in the Republic of Kazakhstan. We compared the two types of larches according to botanical affiliation and species description. We studied the alcoholic extracts from Lárix Kaémpferi and Lárix Sibirica to determine their physical and chemical properties. The data on the chemical composition of extractive compounds were generalized and systematized. The authenticity of Lárix Kaémpferi and Lárix Sibirica was established by external, anatomical, and diagnostic signs in microscopic examination and qualitative reactions. Specific indicators and their norms for raw materials were identified. This is the standard for both types of larch and determines their quality. We experimented with grinding fineness for studied materials and tested the impurities and moisture content of raw materials, total ash, and ash insoluble in a 10% hydrochloric acid solution. Determination of heavy metals and radionuclides was also considered. The quality specifications were developed based on the standardization of fine-scaled larch and Siberian larch.
Asunto(s)
Larix , Metales Pesados , Humanos , Ácido Clorhídrico , Kazajstán , Larix/química , Medicamentos sin Prescripción , Extractos VegetalesRESUMEN
The process of sulfation of arabinogalactan-a natural polysaccharide from Larix sibirica Ledeb.-with sulfamic acid in 1,4-dioxane using different activators has been studied for the first time. The dynamics of the molecular weight of sulfated arabinogalactan upon variation in the temperature and time of sulfation of arabinogalactan with sulfamic acid in 1,4-dioxane has been investigated. It has been found that, as the sulfation time increases from 10 to 90 min, the molecular weights of the reaction products grow due to the introduction of sulfate groups without significant destruction of the initial polymer and sulfation products. Sulfation at 95 °C for 20 min yields the products with a higher molecular weight than in the case of sulfation at 85 °C, which is related to an increase in the sulfation rate; however, during the further process occurring under these conditions, sulfation is accompanied by the destruction and the molecular weight of the sulfated polymer decreases. The numerical optimization of arabinogalactan sulfation process has been performed. It has been shown that the optimal parameters for obtaining a product with a high sulfur content are a sulfamic acid amount of 20 mmol per 1 g of arabinogalactan, a process temperature of 85 °C, and a process time of 2.5 h.
Asunto(s)
Galactanos/aislamiento & purificación , Larix/química , Sulfatos/química , Conformación de Carbohidratos , Galactanos/química , Modelos Moleculares , Peso Molecular , TemperaturaRESUMEN
BACKGROUND AND OBJECTIVES: Dietary fibers have beneficial effects on human health through the interaction with gut microbiota. Larch wood arabinogalactan (LA-AG) is one kind of complex soluble dietary fibers that may be utilized by human gut microbiota. METHODS AND RESULTS: In this study, the LA-AG degradation by gut microbiota were characterized by investigating the change of LA-AG, microbiota composition, and the production of short-chain fatty acids (SCFAs), lactic acid, succinic acid, as well as volatile organic metabolites. During the fermentation, pH decreased continuously, along with the organic acids (especially acetic acid and lactic acid) accumulating. LA-AG was degraded by gut microbiota then some beneficial metabolites were produced. In addition, LA-AG inhibited the proliferation of some gut microbiota (Unclassified_Enterobacteriaceae and Citrobacter) and the accumulation of some metabolites (Sulfide and indole) released by gut microbiota. CONCLUSION: LA-AG was partly fermentable fibers with prebiotic potential for human gut health.
Asunto(s)
Galactanos/metabolismo , Microbioma Gastrointestinal/fisiología , Prebióticos , Bacterias/clasificación , Bacterias/metabolismo , Fibras de la Dieta , Heces/microbiología , Fermentación , Galactanos/química , Humanos , Larix/químicaRESUMEN
The present study explored the use of chitosan films functionalized with antioxidants extracted from Larix decidua Mill. bark for active packaging. The pristine chitosan and extract-incorporated chitosan films were evaluated for their structural, physico-mechanical, thermal, viscoelastic and antioxidant properties using advanced characterization techniques. The infrared spectroscopy revealed hydrogen bonding between the extract polyphenolic antioxidants and chitosan, whereas the surface microscopy studies indicated good compatibility between them. The addition of bark extract caused a significant increase in color parameters and solubility with reduction in swelling and elongation at break of the films. The thermal analysis indicated a drop in thermal stability of chitosan films modified with the extract. The dynamic mechanical analysis confirmed the extract-polymer interactions and the viscoelastic nature of the films. The incorporation of bark extract caused remarkable enhancement in the antioxidant activity of chitosan films. Overall, larch bark extract-functionalized chitosan films demonstrated promising potential for food packaging.
Asunto(s)
Quitosano/química , Embalaje de Alimentos , Depuradores de Radicales Libres/química , Larix/química , Corteza de la Planta/química , Extractos Vegetales/química , Color , Ensayo de Materiales , Permeabilidad , Solubilidad , Resistencia a la TracciónRESUMEN
In this study, lignin-carbohydrate complexes (LCCs) were isolated from biomass (raw and pretreated) to investigate the structural changes in biomass pretreated by Fenton oxidation and hydrothermal treatment, and their effect on enzymatic hydrolysis. The composition and structure of the LCCs fractions were investigated via carbohydrate analysis, XRD, FT-IR, and 2D HSQC NMR. The biomass degradation rate of yellow poplar and larch during Fenton oxidation and hydrothermal treatment was approximately 30%. Most of the hemicellulose was degraded during pretreatment, while xylan remained in the yellow poplar, and galactan, mannan, and xylan remained in the larch. The fractional yield of glucan-rich LCC (LCC1) in the yellow poplar (raw and pretreated biomass) was high, while that of glucomannan-rich LCC (LCC3) in larch was higher than the yield yellow poplar. Phenyl glycoside, γ-ester, and benzyl ether linkages were observed in the LCCs of yellow poplar, while phenyl glycoside and γ-ester were detected in those of larch. Following pretreatment, the frequencies of ß-ß', ß-5, and γ-ester in the LCCs of larch were found to be higher than in those of yellow poplar. The efficiencies of enzymatic hydrolysis for the pretreated yellow poplar and larch were 93.53% and 26.23%, respectively. These finding indicated that the ß-ß', ß-5, and γ-ester linkages included in the pretreated biomass affected the efficiency of enzymatic hydrolysis.
Asunto(s)
Biomasa , Carbohidratos/química , Peróxido de Hidrógeno/química , Hierro/química , Lignina/química , Hidrólisis , Larix/química , Larix/enzimología , Liriodendron/química , Liriodendron/enzimología , Espectroscopía de Resonancia Magnética/métodos , Mananos/química , Oxidación-Reducción , Polisacáridos/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Temperatura , Difracción de Rayos X/métodos , Xilanos/químicaRESUMEN
PURPOSE: Taxifolin is a kind of dihydroflavone and is usually used as a food additive and health food for its antioxidant, anti-inflammatory, and anti-tumor activities. The purpose of this research is to probe into the hepatoprotective activity and the molecular mechanism of taxifolin. MATERIALS AND METHODS: The liver fibrosis model was established by intraperitoneal injection of 5 mL/kg body weight of CCl4 (20% CCl4 peanut oil solution), and taxifolin was dissolved with 0.9% physiological saline and administered intragastrically to mice. RESULTS: The results indicated that CCl4-induced significantly increased the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in mice. Histopathological examination showed severe hepatocyte necrosis and hepatic tissue lesion. Immunohistochemical staining and rt-PCR analysis demonstrated that the expressions of inducible nitric oxide synthetase (iNOS), cyclooxygenase-2 (COX-2), IL-1ß, IL-6, and TNF-α were increased. These changes were significantly reversed when treated with taxifolin. In addition, TUNEL staining and Bcl-2/Bax pathway confirmed that taxifolin significantly inhibited hepatocyte apoptosis. Besides, the research confirmed that taxifolin also inhibited the activation of hepatic stellate cells and the production of extracellular matrix (ECM) by regulating PI3K/AKT/mTOR and TGF-ß1/Smads pathways. CONCLUSION: Taxifolin inhibited inflammation, and attenuated CCl4-induced oxidative stress and cell apoptosis by regulating PI3K/AKT/mTOR and TGF-ß1/Smads pathways, which might in part contributed to taxifolin anti-hepatic fibrosis, further demonstrating that taxifolin may be an efficient hepatoprotective agent.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Tetracloruro de Carbono/antagonistas & inhibidores , Larix/química , Cirrosis Hepática/tratamiento farmacológico , Quercetina/análogos & derivados , Animales , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/aislamiento & purificación , Apoptosis/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Hepatocitos/efectos de los fármacos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Inflamación/patología , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/patología , Masculino , Ratones , Ratones Endogámicos ICR , Conformación Molecular , Estrés Oxidativo/efectos de los fármacos , Fosfatidilinositol 3-Quinasas/metabolismo , Raíces de Plantas/química , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/metabolismo , Quercetina/química , Quercetina/aislamiento & purificación , Quercetina/farmacología , Transducción de Señal/efectos de los fármacos , Proteínas Smad/antagonistas & inhibidores , Proteínas Smad/metabolismo , Relación Estructura-Actividad , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/metabolismo , Factor de Crecimiento Transformador beta1/antagonistas & inhibidores , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
Larch arabinogalactan (AG), extracted from Larix gmelinii sawdust, was depolymerized by H2O2 oxidation and purified by gel column to yield a novel degraded fraction (AGD2). The structural analysis indicated AGD2 had lower arabinose content and molecular weight compared with AG, in which the ratio of galactose and arabinose was changed from 7:3 to 16:1, the molecular weight was decreased from 50.2 kDa to 3.7 kDa, and the chain conformation spread from highly branched structure to flexible strand. It was one kind of ß-D-(1 â 3)-galactan with fewer ß-D-(1 â 6)-Galp side branches at O-6 position. Further, the results of the Gal-3 binding and immunomodulatory assay suggested that the unbinding force of AGD2 onto Gal-3 was as twice as AG to be 76 ± 11 pN at the loading rate of 0.15 µm/s. It could better promote the secretion of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1ß) than AG in a dose-dependent manner.
Asunto(s)
Galactanos/aislamiento & purificación , Larix/química , Madera/química , Animales , Arabinosa/análisis , Proteínas Sanguíneas/antagonistas & inhibidores , Conformación de Carbohidratos , Relación Dosis-Respuesta a Droga , Galactanos/química , Galactanos/farmacología , Galactosa/análisis , Galectinas/antagonistas & inhibidores , Factores Inmunológicos/química , Factores Inmunológicos/aislamiento & purificación , Factores Inmunológicos/farmacología , Interleucina-1beta/biosíntesis , Interleucina-6/biosíntesis , Metilación , Ratones , Microscopía de Fuerza Atómica , Resonancia Magnética Nuclear Biomolecular , Células RAW 264.7 , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
The effects of sulfated organosolv lignins derived from fir (Abies sibirica) and larch (Larix sibirica) (SLf and SLl; 4-3-7.5% sulfur, median-weight molecular mass 2960-4888 Da), on human blood/plasma clotting, platelet aggregation, and erythrocyte hemolysis were studied in vitro. Antithrombin activities of the samples were below 2 U/mg. Specimens of SLf (sulfur content 6.5, 6.6, and 7.5%, molecular weights 3503, 3487, and 3580 Da, respectively) and SLl (4.3 and 6.3%, 2960 and 3497 Da) in a concentration of 0.01 mg/ml did not prolong the blood clotting time, did not provoke human platelet aggregation, did not destroy erythrocyte membranes, and could be used for construction of drug delivery systems. The SLf sample (6.5%, sulfur, 3503 Da) in concentrations from 0.09 to 1.82 mg/ml did not stimulate platelet aggregation, reduced ADP-induced platelet aggregation, and 2-fold prolonged the blood/plasma clotting time 2-fold in comparison with control and could be used for creation of biomaterial with clot-resistant surface.
Asunto(s)
Abies/química , Materiales Biocompatibles/farmacología , Coagulación Sanguínea/efectos de los fármacos , Larix/química , Lignina/farmacología , Adenosina Difosfato/farmacología , Antitrombinas/análisis , Materiales Biocompatibles/química , Materiales Biocompatibles/aislamiento & purificación , Plaquetas/citología , Plaquetas/efectos de los fármacos , Células Cultivadas , Sistemas de Liberación de Medicamentos/métodos , Eritrocitos/citología , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Humanos , Lignina/química , Lignina/aislamiento & purificación , Ensayo de Materiales , Peso Molecular , Agregación Plaquetaria/efectos de los fármacos , Sulfatos/química , Madera/químicaRESUMEN
Probiotics possibly affect local and systemic immune reactions and maintain the intestinal immune homeostasis in healthy individuals and patients with diseases such as irritable bowel syndrome (IBS). In this single-center, blinded trial, we enrolled 40 individuals (20 patients with IBS and 20 healthy individuals) whose blood and fecal samples were collected before and after a 21-day administration of a product comprising Lactobacillus spp., larch arabinogalactan, and colostrum. The percentage of HLA-DR+ natural killer (NK) cells was higher in healthy individuals (p = 0.03) than in patients with IBS after product supplementation. In the fecal samples of patients with IBS, we observed a decline in IL-6, IFN-γ, TNF-α, and secretory IgA levels and, simultaneously, an increase in IL-10 and IL-17A levels after supplementation, although non-significant, whereas, in healthy individuals, we observed a significant decline in IL-6 and IFN-γ levels after supplementation (p < 0.001). Nevertheless, we observed a clinical improvement of symptoms in 65-75% of patients with IBS and the complete resolution of the initial symptoms in five of the 20 patients. We also observed a possible prophylactic effect by the inducing system antiviral impact accompanied by a trend for local immune tolerance in the gut in healthy individuals, where it is the desirable state.
Asunto(s)
Calostro/fisiología , Suplementos Dietéticos , Galactanos/administración & dosificación , Tolerancia Inmunológica , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Síndrome del Colon Irritable/dietoterapia , Síndrome del Colon Irritable/inmunología , Células Asesinas Naturales/inmunología , Lactobacillus , Larix/química , Activación de Linfocitos/inmunología , Adulto , Citocinas/metabolismo , Femenino , Galactanos/aislamiento & purificación , Voluntarios Sanos , Homeostasis , Humanos , Inmunoglobulina A Secretora/metabolismo , Síndrome del Colon Irritable/prevención & control , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Adulto JovenRESUMEN
The naturally occurring quercetin flavonoid, dihydroquercetin, is widely distributed in plant tissues and has a variety of biological activities. Herein, a magnetic molecularly imprinted solid-phase extraction was tailor made for selective determination of dihydroquercetin in Larix griffithiana using high-performance liquid chromatography. Amino-functionalized core-shell magnetic nanoparticles were prepared and characterized using scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, and infrared spectroscopy. The polymer had an average diameter of 250 ± 2.56 nm and exhibited good stability and adsorption for template molecule, which is enriched by hydrogen bonding interaction. Multiple factors for extraction, including loading, washing, elution solvents, and extraction time, were optimized. The limit of detection was 1.23 µg/g. The precision determined at various concentration of dihydroquercetin was less than 4% and the mean recovery was between 74.64 and 101.80%. It has therefore been shown that this protocol can be used as an alternative extraction to quantify dihydroquercetin in L. griffithiana and purify quercetin flavonoid from other complex matrices.
Asunto(s)
Larix/química , Impresión Molecular , Quercetina/análogos & derivados , Extracción en Fase Sólida , Cromatografía Líquida de Alta Presión , Fenómenos Magnéticos , Quercetina/análisisRESUMEN
Heat treatment is a green, environmentally friendly and mild pyrolysis process that improves the dimensional stability and durability of wood. In this study, Larix spp. Samples were heated at 180 °C and 210 °C for 6 h with nitrogen, air or oil as heat-conducting media. The influence of high-temperature heat treatment on the microstructure, chemical components, and micromechanical properties was investigated. The mass loss rate increased with increasing temperature, and the degradation of wood components resulted in cracks in the cell walls. Samples treated with air showed more cracks in cell walls than were observed in the cells walls of wood treated with the other heat-conducting media. The hardness of the cell walls increased after all heat treatments. In addition, the results showed that heat treatment reduced creep behavior compared to that of untreated wood.
Asunto(s)
Fenómenos Químicos , Calor , Larix/química , Madera/química , Pared Celular , Dureza , Pirólisis , Espectroscopía Infrarroja por Transformada de Fourier , Madera/ultraestructuraRESUMEN
Ecofriendly wood-based materials are required by consumers at present. Decorative panels are part of a large group of wood-composite materials, and their environmental properties must not be neglected. More environmentally friendly decorative panels can be achieved by various methods. This paper describes a method of production from larch bark. Tree bark, as a byproduct of the wood industry, is one of the research topics that have gained interest in the last decade, especially for its applications in biobased lignocomposites, with regard to the shrinkage of wood resources. In the present work, the formaldehyde content of decorative boards based on larch bark (0.6 g/cm³) was analyzed when bonded with five different types of adhesive systems: urea-formaldehyde, polyvinyl acetate, the mixture of 70% urea-formaldehyde + 30% polyvinyl acetate, polyurethane, and tannin-based adhesive. A self-agglomerated board was also analyzed. The formaldehyde content of the larch-bark samples was determined with the perforator method (EN 120:2011), and findings showed that all tested samples reached the E1 classification (≤8 mg/100 oven dry). Moreover, 75% of the values of the corrected formaldehyde content were included in the super-E0 class (≤1.5 mg/100 oven dry). In the case of boards bonded with tannin-based adhesive, this natural polymer acted as a formaldehyde scavenger.
Asunto(s)
Adhesivos/química , Materiales de Construcción/análisis , Formaldehído/análisis , Residuos Industriales/análisis , Larix/química , Corteza de la Planta/química , Madera/químicaRESUMEN
Conifer resins are used as chemical raw materials for daily necessities. There have been many reports on the aroma components of turpentine oil from rosin, but there has been no reports on fluctuations in the aroma components through spring to late autumn. We speculated that the aroma components in the essential oils of deciduous coniferous larches might fluctuate during maturation of the foliage. In this study, we focused on the aroma components of larch essential oils and we clarified by multivariate analysis how the aroma components fluctuate during leaf maturation. The results of analysis showed that there was a drastic seasonal fluctuation of the chemical components in larch essential oils, especially in senescent leaves in late autumn. Cryptone and linalool were identified as the characteristic aroma components in essential oil from senescent larch leaves.
Asunto(s)
Larix/química , Odorantes/análisis , Aceites Volátiles/química , Hojas de la Planta/química , Estaciones del Año , Trementina/química , Monoterpenos Acíclicos , Monoterpenos/aislamiento & purificación , Aceites Volátiles/aislamiento & purificación , Hojas de la Planta/crecimiento & desarrollo , Resinas de PlantasRESUMEN
Active urbanization processes exacerbate environmental problems associated with industrial pollution in cities. Urban greening helps reduce level of air pollution and improve microclimate. Selection sensitive plant species (indicators of pollution), and the resistant species (decrease the level pollution) is acute in many countries. The aim of the present work was to establish concentrations of heavy metals (Fe, Mn, Zn, Cu, Ni, Cr, Pb, Co and Cd) in the Siberian larch needles grown in various urban land-use (functional) zones of Ulan-Ude (Russia), as well as to determinate and compare the levels of some biochemical compounds. Based on index of soil contamination, the highest heavy metal pollution was found in the highway and industrial zones. The index of biogeochemical transformation of the needle elements composition ranged from 5.1 (minimal level) to 32.2 (strong level). The most polluted sites were along highways, where Fe, Zn, Cu, Cr, Ni, Pb, and Cd concentration in the needles were up to 2.5-7.7 times than background values. An important role in the protective system of larch is played by pigments, especially Chl b and carotenoids. Their content in the needles is increased by 1.3-2.2 times. Ratio Chl a/b and ∑Chl/carotenoids decrease as compared to background level; in the first case-due to increase of Chl b content, in the second case-increase of carotenoids level. Highest concentrations of proline, condensed tannins and peroxidase activity were found in needles from urban zones connected with high traffic and industrial emission. Based on the Air Pollution Tolerance Index Siberian larch should be considered sensitive species to air pollution and can be recommended as bioindicator.
Asunto(s)
Monitoreo del Ambiente , Larix/metabolismo , Metales Pesados/metabolismo , Contaminantes del Suelo/metabolismo , Contaminantes Atmosféricos/metabolismo , Larix/química , Hojas de la Planta/química , Hojas de la Planta/metabolismo , Federación de RusiaRESUMEN
Flavonoid-mediated materials are promising substances for the design of new functional materials because of their bioactivity, eco-friendliness, and cost-effectiveness. Dihydroquercetin (DHQ) is the major flavonoid in the wood of Larix dahurica Turcz. Previously some new modifications were created on the basis of DHQ, they were characterized by different morphological, physico-chemical and biopharmaceutical properties. This study was performed to research the influence of the solvent on the formation of the solid phase in DHQ microtubes and crystal form as commercially available active pharmaceutical ingredient (API). The choice of the models for the computational simulation was based on the data of differential scanning calorimetry. All calculations were performed using Materials Science Suite. In silico analysis demonstrated that the molecules of solvent are a key player in the formation of the solid phase of the flavonoid-mediated material. Also the comparative analysis of physical characteristics between DHQ microtubes and crystal form was performed. These data give an opportunity to suggest, that DHQ microtubes may have a grate application as the dressing material and in the drug delivering. The results of this study could be helpful for the design of the new flavonoid-mediated materials by crystal engineering.
Asunto(s)
Larix/química , Quercetina/análogos & derivados , Simulación por Computador , Modelos Químicos , Quercetina/químicaRESUMEN
A highly branched arabinogalactan isolated from Larix principis-rupprechtii and subjected to sulfation derivatization to promote their antitumor bioactivity. Several structural features of the sulfated arabinogalactans (S-LAG) were investigated: molecular weight, monosaccharide constitution, and chemical structures. Spectral analysis indicated that sulfate groups were successfully introduced on arabinogalactan. Sulfated products showed different degrees of substitution (DS) ranging from 0.61 to 0.80, and different Mw ranging from 19.24 to 22.03 kDa. Monosaccharide composition before and after sulfation indicated some level of derivatization selectivity. In vitro cancer cell tests demonstrated that S-LAGs were effective inhibitors to cancer cell growth depending on their dosage. The toxicity mechanisms were further investigated, and assay results revealed that S-LAGs mainly induced cancer cellular apoptosis to promote atrophy and inhibit cell proliferation. The results obtained in this work offer strong demonstration of modified arabinogalactans as a potential medical substance for treating different forms of cancer.
Asunto(s)
Antineoplásicos , Galactanos , Larix/química , Antineoplásicos/química , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Galactanos/química , Galactanos/farmacología , Humanos , Sulfatos/química , Ácidos Sulfónicos/químicaRESUMEN
Arabinogalactans are a source of dietary fiber with health benefits. In this work, two arabinogalactans assigned as AGW and AGS were isolated from Larix principis-rupprechtii, and characterized by gel permeation chromatography (GPC), monosaccharide analysis, methylation analysis and NMR spectroscopy analysis. The average molecular weights of AGW and AGS were 1.53 × 104 and 1.84 × 104 Da, respectively. Methylation analysis and NMR spectra suggested that AGW and AGS have a 1,3-linked Galp backbone, branched at C-6 with 1,6-linked Galp side residues. The Ara residues were substituted at C-6 of 1,6-linked Galp consisting of α-L-Araf-(1â3)-α-L-Araf-(1â6)-ß-D-Galp-(1â and ß-L-Arap-(1â6)-ß-D-Galp-(1â. Significantly, AGS (0.74%) was shown to contain 25 times more uronic acid than AGW (0.03%), which demonstrated a polyelectrolyte effect. Application of these two polysaccharides to macrophage RAW 264.7 cells was shown to increase nitric oxide (NO) production. These results provide a basis for studying the relationship between the structure and biological activity of arabinogalactans.
Asunto(s)
Galactanos/química , Galactanos/farmacología , Larix/química , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Óxido Nítrico/biosíntesis , Animales , Secuencia de Carbohidratos , Ratones , Peso Molecular , Monosacáridos/análisis , Células RAW 264.7RESUMEN
In order to prepare functional materials for antioxidant and ultraviolet (UV)-protective green food packaging, condensed tannin, previously extracted from larch bark, was mixed with polyvinyl alcohol (PVA), and then the mixture was used to cast composite membranes. An antioxidative assay using 1,1-diphenyl-2-picrylhydrazyl (DPPH)-a free radical scavenger-and starchâ»potassium iodide oxidationâ»discoloration analyses showed that the composite membranes have good antioxidative activities. The low UV transmission and protective effect of the composite films on vitamin E indicated the UV protection ability of the composite membranes. Both larch bark tannin and PVA are rich in hydroxyl groups; scanning electron microscopy analysis demonstrated their compatibility. Also, the mechanical and crystallization properties of the composite membranes did not significantly decrease with the addition of larch bark tannin.
Asunto(s)
Antioxidantes/química , Antioxidantes/farmacología , Larix/química , Corteza de la Planta/química , Alcohol Polivinílico/química , Taninos/química , Taninos/farmacología , Fenoles/química , Fitoquímicos/química , Espectroscopía Infrarroja por Transformada de Fourier , Protectores Solares/química , Protectores Solares/farmacología , Resistencia a la Tracción , Difracción de Rayos XRESUMEN
The treatment of wood wastes of Castanea sativa L., Quercus frainetto, Larix decidua, and Paulownia tomentosa S. in autoclave in the presence of micrometric crystals of H3PMo12O40 showed an impressive increase of the amount of extractives. The extractives were mainly constituted of insoluble compounds that were analyzed by using gas chromatography-mass spectrometry (GC-MS) after acetylation. The GC-MS analysis of the chloroform soluble fraction of the extractives obtained from sativa showed the presence of methyl hexadecanoate and octadecanoic acid, that of the extractives of frainetto showed the presence of octadecanal and some long chain hydrocarbons. decidua extracts showed the presence of large amounts of sesamin, while the extractives of P tomentosa revealed the presence of 4-hydroxy-3,5-dimethoxybenzaldehyde, 4-hydroxy-3,5-dimethoxycimmanaldehyde, and relevant amounts of long chain hydrocarbons. The insoluble fraction showed the presence of relevant amounts of several carbohydrates and, in the case of C. sativa, of inositol.