High Reduction Ability Research Articles

A novel Z-type multidimensional FeSe2/CuSe heterojunction photocatalyst with high photocatalytic and photoelectrochemical performance

A novel Z-type multidimensional FeSe2/CuSe heterojunction photocatalyst was synthesized by a hydrothermal progress. In the reaction, 1D FeSe2 nanorods will load on the surface of 2D CuSe nanosheets to construct heterojunction. This Z-type heterojunction can improve the carriers separated efficiency and reduce internal resistance (as low as 0.31 kΩ). More importantly, the catalysts display both high oxidation and reduction ability confirmed by photocatalytic and photoelectrochemical test. Under the optimum concentration, the catalyst showed 7.4 times of degradation tetracycline hydrochloride rate, and 4 times of photocurrent density than pure CuSe. Active specie O2−• was detected by the electron spin resonance tool during photocatalytic degradation progress which could confirm that a Z-type heterojunction was constructed between CuSe and FeSe2. In this Z-type heterojunction, photoinduced electrons in the conduction band of FeSe2 can directly inject the valence band of CuSe while photoinduced electrons in the conduction band position of CuSe and photoinduced holes in the valence band position of FeSe2 will remain. The remained photoinduced electrons in the conduction band of CuSe can generate O2−• to oxide tetracycline hydrochloride as well as photoinduced electrons to produce hydrogen. This work highlights a simple strategy of Z-tpye selenides heterostructure for oxidation and reduction application.

Assessment of Permeability Windbreak Forests with Different Porosities Based on Laser Scanning and Computational Fluid Dynamics

Accurate modeling of windbreaks is essential for the precise assessment of wind protection performance. However, in most windbreak studies, the models used the approximate shape of the simulated trees, resulting in significant differences between the simulated results and the actual situation. In this study, terrestrial laser scanning (TLS) was used to extract tree parameters, which were used in a quantitative structural model (AdQSM) to recreate the tree structure and restore the wind field environment using the computational fluid dynamics software PHOENICS. In addition, we compared the bias, precision, and accuracy of porosity of Ginkgo biloba (with elliptical crown) and Populus alba (with conical crown), which have been commonly used in previous windbreak studies. The results showed that AdQSM has a high reduction rate and ability to reproduce the field conditions of the study area. After wind field simulation, the wind speed root mean square errors of the point cloud model at three heights (3, 6, and 9 m) were 0.272, 0.377, and 0.437 m/s, respectively, and the wind speed correlation coefficients r were 0.967, 0.965, and 0.937, respectively, which were significantly more accurate than those of the remaining two structures. Finally, the porosity of the windbreak forest obtained using the modeled sample plot showed a higher correlation with the wind permeability coefficient than that obtained using the existing approach. Windbreak models with three different porosities under the same conditions had different effects on the wind environment, particularly the location of the maximum wind speed reduction, variation of wind speed with porosity, and recovery rate of leeward wind speed. TLS can accurately extract windbreak factors and calculate the porosity, thus greatly improving the reliability of windbreak effect research in windbreak forests. This study provides a promising direction for future research related to the simulation of windbreak effects in windbreak forests.

Role of human gut bacteria in arsenic biosorption and biotransformation.

There is growing evidence that human gut microbiota can metabolize arsenic (As); however, which bacteria play roles in this metabolism is unclear. In this study, we measured the abilities of 21 human gut bacteria strains from diverse clades to adsorb and transform As using in vitro method with the aim of determining which bacteria play a role in As metabolism. Seven strains showed high biosorption of As, ranging from 20.1 to 29.8%, which was attributed to functional groups on the bacterial surfaces, such as hydroxyl, amino, and carboxyl groups. Moreover, six of these seven strains were versatile, as they also had roles in reducing As(V) to As(III), which is mainly regulated by the arsC gene. Escherichia coli had the strongest tolerance to As and the highest reducing ability, with a value of 71.04-73.13µM As/h. This study reveals that gut bacteria play essential roles in As biosorption and biotransformation, and provides a better understanding of which strains are involved, which has implications for the regulation of As toxicity-based gut bacteria and provides basic data for regulating arsenic to human health.

Hemicellulosic Polysaccharides From Bamboo Leaves Promoted by Phosphotungstic Acids and Its Attenuation of Oxidative Stress in HepG2 Cells.

In this work, we exploited an efficient method to release hemicellulosic polysaccharides (BLHP) from bamboo (Phyllostachys pubescens Mazel) leaves assisted by a small amount of phosphotungstic acid. Structural unit analysis proved that BLHP-A1 and BLHP-B1 samples possessed abundant low-branch chains in →4)-β-D-Xylp-(1→ skeleton mainly consisting of Xylp, Manp, Glcp, Galp, and Araf residues. According to the results of the antioxidant activity assays in vitro, both of the two fractions demonstrated the activity for scavenging DPPH⋅ and ABTS+ radicals and exhibited relatively a high reducing ability compared to the recently reported polysaccharides. Moreover, the antioxidant activities of purified polysaccharides were evaluated against H2O2-induced oxidative stress damage in HepG2 cells. BLHP-B1 showed more activity for preventing damages from H2O2 in HepG2 cells by improving the enzyme activities of SOD, CAT, and GSH-Px and decreasing the production of MDA as well as suppressing reactive oxygen species (ROS) formation. This study implied that BLHP could demonstrate its attenuation ability for oxidative stress in HepG2 cells.

Physicochemical properties, molecular structure, antioxidant activity, and biological function of extracellular melanin from Ascosphaera apis.

Ascosphaera apis spores containing a dark-colored pigment infect honeybee larvae, resulting in a large-scale collapse of the bee colony due to chalkbrood disease. However, little is known about the pigment or whether it plays a role in bee infection caused by A. apis. In this study, the pigment was isolated by alkali extraction, acid hydrolysis, and repeated precipitation. Ultraviolet (UV) analysis revealed that the pigment had a color value of 273, a maximum absorption peak at 195 nm, and a high alkaline solubility (7.67%) and acid precipitability. Further chemical structure analysis of the pigment, including elemental composition, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, mass spectrometry, and nuclear magnetic resonance (NMR), proved that it was a eumelanin with a typical indole structure. The molecular formula of melanin is C10H6O4N2, and its molecular weight is 409 Da. Melanin has hydroxyl, carboxyl, amino, and phenolic groups that can potentially chelate to metal ions. Antioxidant function analyses showed that A. apis melanin had a high scavenging activity against superoxide, hydroxyl, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, and a high reducing ability to Fe3+. Indirect immunofluorescence assay (IFA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses showed that A. apis melanin was located on the spore wall. The spore wall localization, antioxidant activity, and metal ion chelating properties of fungal melanin have been suggested to contribute to spore pathogenicity. However, further infection experiments showed that melanin-deficient spores did not reduce the mortality of bee larvae, indicating that melanin does not increase the virulence of A. apis spores. This study is the first report on melanin produced by A. apis, providing an important background reference for further study on its role in A. apis.

Protein-Protein Interactions Followed by in-Situ Synthesis of Gold Nanoparticles

Protein-protein interaction (PPI) plays an important role in various biochemical processes. Various binary mixtures of industrially important zein have been blended with rice and wheat proteins to expand their biological applicability. Zein-rice, zein-hard wheat, and zein-soft wheat mixtures show different behavior toward in vitro synthesis of Au NPs. This can also be explained by the TEM, FESEM, and DLS studies of PPI-Au NPs mixtures. Zein-rice-Au NPs mixture showed their mutual favorable interaction with high colloidal stability and high reduction ability towards nucleating Au NPs. This may be due to both hydrophobic and hydrophilic interaction of zein-rice PPI, which resulted in regular and shape-controlled Au NPs. In the case of zein-wheat PPI interaction, lesser hydrophobic interaction resulted in the incomplete unfolding of wheat protein and demixing of wheat protein with zein protein to anisotropic and irregular Au NPs. The study of these interactions will lead to the development of therapeutic centers toward different diseases and their environmental applications.

Nitrogen-stabilized oxygen vacancies in TiO2 for site-selective loading of Pt and CoOx cocatalysts toward enhanced photoreduction of CO2 to CH4

Photocatalysis provides an attractive approach to convert CO2 into valuable fuels, which yet highly relies on a well-designed photocatalyst with good selectivity and high CO2 reduction ability. Herein, we report a mild synthesis of mesoporous spherical N-doped TiO2 photocatalyst with site-selective deposition of redox cocatalysts. Theoretical calculations prove that nitrogen doping favors the formation of oxygen vacancies (VO) in TiO2 and stabilizes them as well. The combination of ESR characterization, theoretical calculation and photocatalytic tests confirms VO-induced site-selective loading of the redox cocatalysts (Pt, CoOx). The designed composite shows a maximal CH4-yielding rate of 409.17 μmol g−1, which is 180 times higher than that of pure TiO2. Photoelectrochemical and optical measurements indicate that Pt is the key active center for CO2 adsorption and activation, while CoOx is responsible for H2O oxidization and proton transfer. The separation of reaction site and accelerated mass transfer on the catalyst surface largely enhance the conversion efficiency of CO2. This work provides a strategy to selectively deposit dual cocatalysts on semiconductor surface through introduction of oxygen vacancies for substantially improved photocatalytic reduction of CO2.

In-situ construction of direct Z-scheme sea-urchin-like ZnS/SnO2 heterojunctions for boosted photocatalytic hydrogen production

Constructing direct Z-scheme heterostructure is an effective way to promote the separation of photogenerated carriers and optimize the redox ability of the photocatalytic system. This work reports the in-situ synthesis of sea-urchin-like ZnS/SnO2 Z-scheme heterojunctions via a one-step hydrothermal method. Both experimental results and density functional theory (DFT) calculations indicate that the tight interfaces derived from in-situ precursor dissociation can ensure a fast transfer for photogenerated carriers, meanwhile, the Z-scheme type of heterojunctions can increase the carrier separation efficiency and maintain the high reduction ability of photogenerated electrons. As expected, the photocatalytic hydrogen evolution rate of the as-optimized ZnS/SnO2 sample can reach 2.17 mmol g−1 h−1, which is 15.5 times higher than that of the commercial ZnS. This work can offer a novel strategy for designing Z-scheme heterojunction as well as controlling the contact interface for boosted photocatalytic activity.

Cholesterol-lowering effect of bile salt hydrolase from a Lactobacillus johnsonii strain mediated by FXR pathway regulation.

Hypercholesterolemia is a major risk factor for cardiovascular diseases worldwide. Healthy intestinal microbiota can contribute to reducing the high cholesterol symptoms by producing bile salt hydrolase (BSH). In this study, recombinant BSH from the strain L. johnsonii 334 with high cholesterol reduction ability was selected to study the cholesterol-lowering mechanism mediated by farnesoid X receptor (FXR) regulation in mice. In the presence of recombinant BSH, mice had a larger bile acid pool. Analysis of individual bile acids revealed that bile acid composition was affected not only by recombinant BSH but also by the modulated gut microbiota. We confirmed a marked reduction in the transcription of FXR and its molecular targets in the ileum and a significant increase in the transcription of cholesterol 7a-hydroxylase (CYP7A1), which resulted in the increased bile acid synthesis and cholesterol-lowering effects. Notably, our work reveals the importance of BSH substrate specificity.

Phytochemical Profile and Biological Activities of the Extracts from Two Oenanthe Species (O. aquatica and O. silaifolia).

This study presents the evaluation of biological activities and chemical profiling of Oenanthe aquatica (L.) Poir. and Oenanthe silaifolia M. Bieb. The phytochemical profile, antioxidant, enzyme inhibitory, cytotoxic and antiviral activities of the methanolic and aqueous extracts were investigated. The aqueous extract of O. aquatica possessing the highest content of phenolics (60.85 mg gallic acid equivalent/g extract), also exhibited the strongest radical scavenging potential against 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (79.46 and 148.66 mg Trolox equivalent/g extract, respectively), the highest reducing ability (207.59 and 107.27 mg Trolox equivalent/g extract, for cupric reducing antioxidant capacity and ferric reducing antioxidant activity, respectively), metal chelating potential (33.91 mg ethylenediaminetetraacetic acid equivalent/g extract) and total antioxidant ability (1.60 mmol Trolox equivalent/g extract). Liquid chromatography-electrospray ionization-quadrupole time-of-flight-mass spectrometry (LC-ESI-QTOF-MS/MS) permitted tentative identification of compounds from simple organic acids, phenolic acids, coumarins, flavonoids and their glycosides in O. aquatica and O. silaifolia extracts. The methanolic extract of O. aquatica substantially depressed acetylcholinesterase (3.67 mg galantamine equivalent/g extract), tyrosinase (126.66 mg kojic acid equivalent/g extract), and α-amylase (0.83 mmol acarbose equivalent/g extract) enzymes. The methanolic extract of O. silaifolia showed highest enzymatic inhibitory property against butyrylcholinesterase, and its aqueous extract depressed α-glucosidase activity (0.26 mmol acarbose equivalent/g extract). All tested extracts exerted selective toxicity towards cancer cell lines, and the highest anticancer potential was found for O. aquatica aqueous extract on FaDu and HeLa cells with CC50 of 57.36 and 47.16 µg/mL, respectively. Significant antiviral activity against HSV-1 (HHV-1) was found for both aqueous extracts in concentrations of 1000 µg/mL, which inhibited the HSV-1 cytopathic effect (CPE) in virus infected VERO cells and reduced the virus infective titer by more than 3 log (logCCID50/mL). This study has produced critical scientific data on O. aquatica and O. silaifolia, which are potential contenders for the development of novel phyto-pharmaceuticals.

Mesoporous tellurium oxide incorporated g-C3N4 for boosted photoinduced – visible-light reduction of Hg(II)

Two-dimensional (2D) tellurium oxide (TeO2) nanoparticles were homogenously incorporated porous graphitic carbon nitride (g-C3N4) utilizing a simple synthesis sol–gel approach in the occurrence of soft and hard templates. The photocatalytic performance of TeO2/g-C3N4 photocatalysts was performed to reduce Hg(II) ions during visible light illumination. α-TeO2 NPs as tetragonal phases are uniformly scattered with small particle size (15 nm) onto layer structure of g-C3N4. The highest photocatalytic performance (100%) within 40 min is 3 %TeO2/g-C3N4 photocatalyst, and it was enhanced 6.66 and 3.7 folds larger than bare g-C3N4 and TeO2. The rate constant of 3 %TeO2/g-C3N4 photocatalyst is fostered nearly 7.6 and 14.3 times larger than the bare TeO2 NPs and g-C3N4. TeO2 with a nanoscale diameter size (∼15 nm) exhibited a higher photoreduction rate and faster kinetics. Such high reduction ability over TeO2/g-C3N4 photocatalyst was ascribed to the advantageous construction of TeO2/g-C3N4 heterojunction, the synergistic effects of TeO2 and g-C3N4 and the enhancement in electron mobility and efficient electrons and holes separation rate. Owing to such advantageous properties, the 2D- TeO2/g-C3N4 photocatalyst presents promising application potentials as a high-performance photoreduction process.

Contribution of Microorganisms to Biogenic Amine Accumulation during Fish Sauce Fermentation and Screening of Novel Starters.

In this study, high-throughput sequencing and culture-dependent and HPLC methods were used to investigate the contribution and regulation of biogenic amines (BAs) by dominant microorganisms during fish sauce fermentation. The results showed that the microbial composition constantly changed with the fermentation of fish sauce. Tetragenococcus (40.65%), Lentibacillus (9.23%), Vagococcus (2.20%), Psychrobacter (1.80%), Pseudomonas (0.98%), Halomonas (0.94%) and Staphylococcus (0.16%) were the dominant microflora in fish sauce. The content of BAs gradually increased as the fermentation progressed. After 12 months of fermentation, the histamine content (55.59 mg/kg) exceeded the toxic dose recommended by the Food and Drug Administration (FDA). Correlation analysis showed that dominant microorganisms have a great contribution to the accumulation of BAs. By analyzing the BA production capacity of dominant isolates, the accumulation of BAs in fish sauce might be promoted by Tetragenococcus and Halomonas. Moreover, four strains with high BA reduction ability were screened out of 44 low BA-producing dominant strains, and their influence on BA accumulation in fermented foods was determined. Results demonstrated that Staphylococcus nepalensis 5-5 and Staphylococcus xylosus JCM 2418 might be the potential starters for BA control. The present study provided a new idea for the control of BAs in fermented foods.

Boosting graphene electrocatalytic efficiency in oxygen reduction reaction by mechanochemically induced low-temperature nitrogen doping

Mechanochemically induced low-temperature preparation of nitrogen-doped few-layer graphenes (N-Gr) and their application as electrocatalysts of oxygen reduction reaction (ORR) in alkaline medium was shown. The proposed approach allowed achieving a high proportion of graphitic nitrogen atoms. Such doping of N-Gr caused healing of vacancies in its structure, and also lead to the increased charge carrier density and high reduction ability that support advanced electrocatalytic characteristics in ORR (the onset and half-wave potentials equal to 0.98 and 0.77 V vs RHE, the average electron transfer number close to four, the Tafel slope about 60 mV/dec), the absolute values of which are close to those of the platinum-based catalyst. A model of N-Gr-based zinc-oxygen cell could provide a discharge current density of ∼40 mA/cm2 at a potential of 1 V and peak power density about 100 mW/cm2, as well as high cathode stability during cycling.

Evaluation of Cr(VI) Reduction Using Indigenous Bacterial Consortium Isolated from a Municipal Wastewater Sludge: Batch and Kinetic Studies

Hexavalent Chromium (Cr(VI)) has long been known to be highly mobile and toxic when compared with the other stable oxidation state, Cr(III). Cr(VI)-soluble environmental pollutants have been detected in soils and water bodies receiving industrial and agricultural waste. The reduction of Cr(VI) by microbial organisms is considered to be an environmentally compatible, less expensive and sustainable remediation alternative when compared to conventional treatment methods, such as chemical neutralization and chemical precipitation of Cr. This study aims to isolate and identify the composition of the microbial consortium culture isolated from waste activated sludge and digested sludge from a local wastewater treatment plant receiving high loads of Cr(VI) from an abandoned chrome foundry in Brits (North Waste Province, South Africa). Furthermore, the Cr(VI) reduction capability and efficiency by the isolated bacteria were investigated under a range of operational conditions, i.e., pH, temperature and Cr(VI) loading. The culture showed great efficiency in reduction capability, with 100% removal in less than 4 h at a nominal loading concentration of 50 mg Cr(VI)/L. The culture showed resilience by achieving total removal at concentrations as high as 400 mg Cr(VI)/L. The consortia exhibited considerable Cr(VI) removal efficiency in the pH range from 2 to 11, with 100% removal being achieved at a pH value of 7 at a 37 ± 1 °C incubation temperature. The time course reduction data fitted well on both first and second-order exponential rate equation yielding first-order rate constants in the range 0.615 to 0.011 h−1 and second order rate constants 0.0532 to 5 × 10−5 L·mg−1·h−1 for Cr(VI) concentration of 50–400 mg/L. This study demonstrated the bacterial consortium from municipal wastewater sludge has a high tolerance and reduction ability over a wide range of experimental conditions. Thus, show promise that bacteria could be used for hexavalent chromium remediate in contaminated sites.

Polydopamine-assisted polyethylenimine grafting melamine foam and the application in wastewater purification

Melamine foam (MF) is a widely used commercial product and exhibits wide applications in many fields ranging from building, transportation to daily chemical product. Recent researches confirm that the special three-dimensional (3D) framework structure of MF can be an ideal substrate to prepare functional materials. In this work, the water-soluble polyethylenimine (PEI) was grafted onto the framework of MF to develop the water purification material toward heavy metal ions removal. The grafting of PEI on MF was achieved with the aids of polydopamine (PDA) coating and epoxy chloropropane (ECH) cross-linking successively. The 3D framework of MF could be well reserved and PEI was homogeneously grafted onto the framework surface. The adsorption capacity of the adsorbent was dependent upon the molecular wight of PEI. Lower PEI molecular weight endowed the adsorbent with better adsorption ability. The maximum adsorption capacity reached 328.95 mg/g, and the adsorbent exhibited extremely high adsorption stability with increasing cycling measurement numbers. Further results showed that the adsorbent also exhibited high reduction ability and induced about 62.5% toxic Cr(VI) to be reduced. This work confirms that the PEI-modified MF sample is a promising adsorbent in the removal of heavy metal ions and it can be used in wastewater treatment.

0D/3D ZnIn2S4/Ag6Si2O7 nanocomposite with direct Z-scheme heterojunction for efficient photocatalytic H2 evolution under visible light

Constructing heterojunction structure is a feasible way to realize an efficient and durable photocatalysts. Herein, a novel Z-scheme zero/three dimensional (0D/3D) ZnIn2S4/Ag6Si2O7 (ZIS/ASO) composite was rationally designed, synthesized and analyzed. ZIS/ASO composite possesses a layer structure for increasing light response, a special 0D/3D structure for reducing the photo-induce carriers migration path, and numerous active sites for absorbing H2O and producing H2. This composite retains the high oxidation and reduction ability by facilitating separation and migration as well as limiting recombination of photo-induced carriers via the intimate interface between ZIS and ASO. Undoubtedly, the synthesized ZIS/ASO photocatalyst achieved a high photocatalytic H2 activity, and the optimum sample shows a satisfactory H2 evolution rate of 590.56 μmol g−1 h−1, distinctly better than that of pure ZIS. More importantly, this composite exhibits high stability and recyclability and is expected to be applied in practical application. Based on the H2 evolution experimental results and electrochemical tests, the Z-scheme heterostructure construction of the composite was confirmed. This work expects to inspire a unique protocol for synthesizing Z-scheme photocatalysts for water splitting under visible light irradiation.

Tandem photoelectrochemical and photoredox catalysis for efficient and selective aryl halides functionalization by solar energy

Tandem photoelectrochemical and photoredox catalysis for efficient and selective aryl halides functionalization by solar energy

Purification and Structural Characterization of Dendrobium officinale Polysaccharides and Its Activities.

In this study, Dendrobium officinale polysaccharide (named DOPS-1) was isolated from the stems of Dendrobium officinale by hot-water extraction and purified by using Sephadex G-150 column chromatography. The structural characterization, antioxidant and cytotoxic activity were carried out. Based on the results of HPLC, GC, Congo red experiment, together with periodate oxidation, Smith degradation, SEM, FT-IR, and NMR spectral analysis, it expressed that DOPS-1 was largely composed of mannose, glucose and galacturonic acid in a molar ratio of 3.2 : 1.3 : 1. The molecular weight of DOPS-1 was 1530 kDa and the main chain was composed of (1→4)-β-D-Glcp, (1→4)-β-D-Manp and 2-O-acetyl-(1→4)-β-D-Manp. The measurement results of antioxidant activity showed that DOPS-1 had the strong scavenging activities on hydroxyl radicals, DPPH radicals and superoxide radicals and the high reducing ability in vitro. Moreover, DOPS-1 was cytotoxic to all three human cancer cells of MDA-MB-231, A549 and HepG2.

A DFT study on carbon dioxide reduction of low-valent diuranium complex supported by a polypyrrolic macrocycle

To mitigate carbon emission and satisfy the ever-increasing energy demands, a flourishing area of research is to design and develop innovating actinide-containing catalysts, which enables CO2 reduction at modest condition. In this regard, a polypyrrolic diuranium(III) complex (1) was examined using relativistic DFT. The reaction of 1 with CO2 is exothermic. The onwards 1-OCO → 1-OOC transformation was found kinetically feasible. Furthermore, the hydrogenation and CO elimination reactions were also calculated. The proposed mechanism indicates that both U(III) centers having high reducing ability provide two electrons with the assistance of the U-U bonding and cooperatively catalyze the CO2 cleavage.

Phytochemical characterization of phloem in maritime pine and stone pine in three sites in Portugal

This study analyzes the content and chemical profile of extractives present in the young phloem of mature trees of maritime pine (Pinus pinaster) and stone pine (P. pinea) in three sites in Portugal located in different climatic environments.The cross-sites average of extractives was similar in both pines with 38.5% in P. pinea and 37.7% in P. pinaster phloem. The hydrophilic fraction represented 82% and 70% of P. pinea and P. pinaster total extractives respectively, with large contents of phenolic compounds, flavonoids and tannins, and showed very high oxygen scavenging and reducing ability. Lipophilic extractives were present in higher proportion in P. pinaster phloem than in P. pinea phloem, and showed a large content of resin acids, with the predominance of abietic acid in P. pinaster, and dehydroabietic acid in P. pinea phloems, and of alkanoic acids.P. pinaster and P. pinea have specific defences related to phloem production of resin and phenolic compounds with the ratio phenolic-to-oleoresin compounds higher for P. pinea (4.7 vs 2.3 for P. pinaster) and constant in the three sites. The phytochemical content and composition of the young phloem of P. pinaster and P. pinea showed site differences highlighting the relationship between environment and metabolic production.