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Artificial coastal protection forests are difficult to manage because of nutrient stress in harsh environment. To explore the effects of salt and phosphorus stress on the seed germination and seedling growth of Casuarina equisetifolia and Acacia confusa, we respectively watered the seeds and seedlings of the two kinds of plants with the solutions of NaCl (salt) and KH2PO4 (phosphorus) in different concentrations, and then determined their growth indicators, respectively. The results were as follows: (1) High salt concentration solutions significantly inhibited seed germination and had a certain effect on the growth of seedlings, however, the effects of salt stress on seed gemination and growth were different. The salt tolerance of Acacia confusa seed germination was higher than that of Casuarina equisetifolia. The biggest relative salt damage rate of Acacia confusa was 23.03% and that of Casuarina equisetifolia was 89.15%. As the concentration of NaCl increased, the germination rate, germination potential, germination index and vitality index of Casuarina equisetifolia and Acacia confusa seeds decreased. And the maximums of the four germination indexes of Casuarina equisetifolia seed were 38.70%, 34.67%, 18.70 and 0.055, and of Acacia confusa seeds were 76.67%, 62.22%, 48.46 and 6.11, respectively. (2) The height and root length of the plants decreased with the increase of salt concentration. The plant heights of Casuarina equisetifolia and Acacia confusa were 12.29 to 6.01 mm and 48.27 to 17.33 mm, and the root lengths were 8.57 to 1.45 mm and 33.41 to 5.88 mm, respectively. The biomass of root, stem and leaf as well as root shoot ratio of Acacia confusa gradually decreased with the increase of salt concentration, but the differences between the treatments of Casuarina equisetifolia were not obvious. 0.6% and 0.4% salt stress were the thresholds for seed germination and seedling growth of the two plants, respectively. (3)The seed and seedling of Acacia confusa were more tolerant to low-phosphorus environment than Casuarina equisetifolia, and there was a difference in the optimum phosphorus concentration between the two. When the phosphorus concentration was 0.1 mmol·L-1, the seed germination rate(49.33%), germination index (23.12%) and vitality index(0.093) of Casuarina equisetifolia, as well as the biomass of root, stem and leaf, all reached the maximum. In the 5 mmol·L-1 treatment, the maximums of germination rate(81.11%), germination potential(62.22%), gemination index(38.23), vitality index(5.07), plant height (54.48 mm) and root length (37.16 mm) of Acacia confusa seeds all appeared, while their germination was inhibited in the treatment of 10 mmol·L-1. Therefore, when sowing the seed of coastal defense forest or planting its seedling, the sowing or planting mode must be selected according to the soil salt and phosphorus contents.

Tyrosinase inhibitors are capable of preventing unfavorable enzymatic browning of fruits and vegetables. In this study, the capacity of Acacia confusa stem bark proanthocyanidins (ASBPs) to inhibit tyrosinase activity was evaluated. ASBPs were shown to be a high-potential inhibitor of tyrosinase with IC50 values of 92.49 ± 4.70 and 61.74 ± 8.93 μg/mL when using L-tyrosine and L-DOPA as the substrate, respectively. The structural elucidation performed with UV-vis, FT-IR spectroscopy, ESI-MS and thiolysis coupled to HPLC-ESI-MS suggested that ASBPs had structural heterogeneity in monomer units and interflavan linkages and consisted mainly of procyanidins dominant with B-type linkages. To gain insights into the inhibitory mechanisms of ASBPs against tyrosinase, different spectroscopic and molecular docking methods were further conducted. Results validated that ASBPs possessed the ability to chelate copper ions and could prevent the oxidation process of substrates by tyrosinase. The hydrogen bond formed with Lys-376 residue played a key role in the binding force of ASBPs with tyrosinase that induced a certain alteration in the microenvironment and secondary structure of tyrosinase, resulting in the enzymatic activity being ultimately restricted. It was also observed that ASBPs treatment effectively inhibited the activities of PPO and POD to retard the surface browning of fresh-cut asparagus lettuce and thus extended their shelf-life. The results provided preliminary evidence supporting the exploitation of ASBPs into potential antibrowning agents for the fresh-cut food industry. [ABSTRACT FROM AUTHOR]

Artificial coastal protection forests are difficult to manage because of nutrient stress in harsh environment. To explore the effects of salt and phosphorus stress on the seed germination and seedling growth of Casuarina equisetifolia and Acacia confusa, we respectively watered the seeds and seedlings of the two kinds of plants with the solutions of NaCl(salt)and KH2PO4(phosphorus)in different concentrations, and then determined their growth indicators, respectively. The results were as follows:(1)High salt concentration solutions significantly inhibited seed germination and had a certain effect on the growth of seedlings, however, the effects of salt stress on seed gemination and growth were different. The salt tolerance of Acacia confusa seed germination was higher than that of Casuarina equisetifolia. The biggest relative salt damage rate of Acacia confusa was 23.03% and that of Casuarina equisetifolia was 89.15%. As the concentration of NaCl increased, the germination rate, germination potential, germination index and vitality index of Casuarina equisetifolia and Acacia confusa seeds decreased. And the maximums of the four germination indexes of Casuarina equisetifolia seed were 38.70%, 34.67%, 18.70 and 0.055, and of Acacia confusa seeds were 76.67%, 62.22%, 48.46 and 6.11, respectively.(2)The height and root length of the plants decreased with the increase of salt concentration. The plant heights of Casuarina equisetifolia and Acacia confusa were 12.29 to 6.01 mm and 48.27 to 17.33 mm, and the root lengths were 8.57 to 1.45 mm and 33.41 to 5.88 mm, respectively. The biomass of root, stem and leaf as well as root shoot ratio of Acacia confusa gradually decreased with the increase of salt concentration, but the differences between the treatments of Casuarina equisetifolia were not obvious. 0.6% and 0.4% salt stress were the thresholds for seed germination and seedling growth of the two plants, respectively.(3)The seed and seedling of Acacia confusa were more tolerant to low-phosphorus environment than Casuarina equisetifolia, and there was a difference in the optimum phosphorus concentration between the two. When the phosphorus concentration was 0.1 mmol·L-1, the seed germination rate(49.33%), germination index(23.12%)and vitality index(0.093)of Casuarina equisetifolia, as well as the biomass of root, stem and leaf, all reached the maximum. In the 5 mmol·L-1 treatment, the maximums of germination rate(81.11%), germination potential(62.22%), gemination index(38.23), vitality index(5.07), plant height(54.48 mm)and root length(37.16 mm)of Acacia confusa seeds all appeared, while their germination was inhibited in the treatment of 10 mmol·L-1. Therefore, when sowing the seed of coastal defense forest or planting its seedling, the sowing or planting mode must be selected according to the soil salt and phosphorus contents. [ABSTRACT FROM AUTHOR]

Tyrosinase inhibitors are capable of preventing unfavorable enzymatic browning of fruits and vegetables. In this study, the capacity of Acacia confusa stem bark proanthocyanidins (ASBPs) to inhibit tyrosinase activity was evaluated. ASBPs were shown to be a high-potential inhibitor of tyrosinase with IC50 values of 92.49 ± 4.70 and 61.74 ± 8.93 μg/mL when using L-tyrosine and L-DOPA as the substrate, respectively. The structural elucidation performed with UV-vis, FT-IR spectroscopy, ESI-MS and thiolysis coupled to HPLC-ESI-MS suggested that ASBPs had structural heterogeneity in monomer units and interflavan linkages and consisted mainly of procyanidins dominant with B-type linkages. To gain insights into the inhibitory mechanisms of ASBPs against tyrosinase, different spectroscopic and molecular docking methods were further conducted. Results validated that ASBPs possessed the ability to chelate copper ions and could prevent the oxidation process of substrates by tyrosinase. The hydrogen bond formed with Lys-376 residue played a key role in the binding force of ASBPs with tyrosinase that induced a certain alteration in the microenvironment and secondary structure of tyrosinase, resulting in the enzymatic activity being ultimately restricted. It was also observed that ASBPs treatment effectively inhibited the activities of PPO and POD to retard the surface browning of fresh-cut asparagus lettuce and thus extended their shelf-life. The results provided preliminary evidence supporting the exploitation of ASBPs into potential antibrowning agents for the fresh-cut food industry.

The micropropagation system described is a commercially viable method for asexual propagation of a mature 'elite' tree of Acacia confusa. The main stem of a mature tree was hardly pruned to induce new shoots for the explants. This study showed that PPM™ (Plant Preservative Mixture) was an effective agent for controlling the contamination of nodal explants and was added to the initial culture medium. This medium consisted of Murashige and Skoog (MS) basal salts and vitamins, supplemented with 4.0 mg L−1 BA, 0.1 mg L−1 IBA, 10 mg L−1 GA, 12 mg L−1 AS, 3.2 g L−1 PVP, and 2.0 mL L−1 PPM™, and was adequate for the establishment of in vitro mother stock for proliferation. The excellent growth response of nodal explants, obtained from May to July in 2019 to 2020, had shoot formation rate ranging from 15.8 to 18.5%. The optimal shoot multiplication was derived on MS medium supplemented with 1.0 mg L−1 BA, 0.5 mg L−1 TDZ, 12 mg L−1 AS, and 500 mg L−1 glutamine which could support feasible 23.7 ± 3.4 shoot proliferation per explant. Shoots generated in vitro with a length of 3 to 5 cm were excised and cultured on MS with 1.0 mg L−1 IBA for rooting. The rooting frequency could be increased to 72.2% within 6 wk. Rooted plantlets in vitro were acclimatized for 4 wk before transplanting to the pots in a greenhouse. [ABSTRACT FROM AUTHOR]

In this study, oriented bamboo scrimber board (OBSB) was manufactured with a synthesized formaldehyde-free tannin adhesive. The chemical properties of the tannin adhesive were analyzed with 13C nuclear magnetic resonance spectroscopy (13C-NMR) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). Results revealed that 70% aqueous acetone extractives of Acacia confusa bark (AcBAE) contained abundant phenolic compounds and condensed tannins comprising mainly B-type flavonoid bonds. Moreover, cross polarization magic angle spinning (CP/MAS) 13C-NMR mapping of cured Acacia confusa bark tannin glue (AcBTanGlu) revealed that condensed tannin reacted with hexamethylenetetramine to form a polymer with a cross-link structure through a polymerization mechanism. According to the results obtained from gas chromatography-flame ionization detector (GC-FID) analysis, no formaldehyde was emitted from AcBTanGlu-glued OBSB. Thermogravimetric analysis indicated that AcBTanGlu significantly improved the thermal stability of AcBAE after the curing reaction. Comparison of the DRIFT spectra of bamboos before and after AcBTanGlu-glued treatment indicated AcBTanGlu did not impact the chemical functional properties of the bamboo. Compared to phenol formaldehyde (PF) and urea formaldehyde (UF)-glued OBSBs, AcBTanGlu-glued OBSBs statistically had lower modulus of elasticity (MOE) and modulus of rupture (MOR). As for the nail withdraw resistance, AcBTanGlu-glued OBSBs are statistically comparable to PF-glued OBSBs and higher than UF-glued OBSBs. [ABSTRACT FROM AUTHOR]

Previous studies have clearly demonstrated that the polyphenols of the ethyl acetate (EtOAc) fraction in the heartwood extract from Acacia confusa (AcHWE) had good photostabilities to prevent photodegradation of wood. The wood photostabilizing actions of condensed tannins and flavonoids from the EtOAc fraction in AcHWE have been individually established, but the effects of these polyphenols on photo-induced discoloration are unknown and merit investigation. The results of this study showed that the six sub-fractions (EA1–EA6), which were fractionated from the EtOAc fraction in AcHWE and contained various condensed tannins and flavonoids, caused different photo-induced discoloration of treated wood. Treating the wood with abundant condensed tannins with little or no flavones and flavonols gave a dramatic dark reddish discoloration after irradiation. Treating the wood with abundant flavones and flavonols with/without condensed tannins produced a moderate dark reddish discoloration with faded yellow tone after irradiation. However, if there are abundant flavanones in the treated wood, their flavanones could transform to chalcones, which increased the yellow tone of treated wood surfaces after initial irradiation. These results illustrated explicit discoloration tendencies for polyphenols in the photodegradation processes for wood and can be the references for further applications. [ABSTRACT FROM AUTHOR]

Lignin, one of the three major components in wood, can absorb UV light and react with 1O2, leading to wood photodegradation. Previous studies demonstrated the ethyl acetate (EtOAc) fraction of the heartwood extract in Acacia confusa (AcHW) has good photostabilities to prevent photodegradation of the wood. However, these effective constituents have different structural characteristics and may affect their photostabilities and protection efficacies on wood which need to be clarified. This study analyzed the polyphenolic contents, chemical constituents and photostabilities of the six subfractions (EA1-EA6) which successively fractioned from the EtOAc fraction in AcHW by the colorimetric methods, UV/Vis spectrophotometry and high-performance liquid chromatography and evaluated the wood photoprotection abilities of these treatments. The results showed the more flavones and flavonols contained in the subfractions, the better the UVA absorptivity was. Besides, the catecholic-condensed tannins and flavonoids in these subfractions also provide good 1O2 quenching abilities and phenoxyl radical scavenging abilities. Advanced results also established in these subfractions, melanoxetin, transilitin, 7,3′,4′-trihydroxy-3-methoxyflavone, 7,8,3′-trihydroxy-3,4′-dimethoxyflavone (flavonols), 7,8,3′,4′-tetrahydroxyflavone, 7,3′,4′-trihydroxyflavone, 7,3′,4′-trihydroxy-5-methoxyflavone (flavones) and okanin (chalcone) can absorb the energy of UVA light; the condensed tannins, 3,4-dihydroxybenzoic acid (phenolic acid), melacacidin-based oligomers, melacacidin, 4-O-methylmelacacidin, 4′-O-methylmelacacidin (melacacidin-based flavanols), 3,7,8,3′,4′-pentahydroxyflavanone (flavanonol), 7,8,3′,4′-tetrahydroxyflavanone (flavanone), the flavones, flavonols and chalcone can suppress the phenoxyl radicals; the condensed tannins, melacacidin-based oligomers and the flavonoids can quench 1O2. Hence, the photostability of extract-free wood slices treated with these effective constituents was consequently enhanced. In summary, these results clearly demonstrated the multiple wood photoprotection actions of these effective constituents and their potential as natural wood photostabilizers. [ABSTRACT FROM AUTHOR]

Compared to toxic and carcinogenic synthetic photostabilizers, application of plant phenolics as natural photostabilizers is more environmentally friendly. Previous works demonstrated the heartwood extract (HWE) of Acacia confusa has the potential to be a natural wood photostabilizer. However, its exact photostabilities and wood photoprotection abilities are not fully understood. This study aimed to illustrate the photostabilities of the HWE on wood and to recognize the effective components in HWE. The results obtained from the wood photoprotection test and photostability analyses revealed that HWE and its fractions possessed wood photoprotection abilities to retard lignin photodegradation, especially HWE and its EtOAc fraction, due to the abundant catecholic flavonoids endowing the multiple photostabilities, including UVA absorptivity, singlet oxygen quenching ability and phenoxyl radical scavenging efficacy. In addition, the photostability-guided isolation method was successively established for investigating the multiple photostabilization actions of HWE. Accordingly, this method can be applied as the standard procedure for isolating photostabilizers from plant secondary metabolites. [ABSTRACT FROM AUTHOR]

One limiting for factor the production of oyster mushrooms was difficult to obtain the raw material of sengon wood sawdust, meanwhile, the production of oyster mushroom necessary need the nutrients in the form of bran or cornmeal. The purpose of this study was to study planting medium, the concentration of corn cob flour, and to find the effective interaction of these two factors on growth and yield of oyster mushroom. This study used a completely randomized design (CRD) with two factors, concentration of media and corn cob flour. The media used in this study are sengon sawdust, glugu sawdust, acacia wood sawdust, rice straw and bagasse, while the concentration of corn cob flour was 0% per baglog, 1% per baglog, 2% per baglog, 3% per baglog and 4% per baglog. Data analysis was using F test level 5% and continued with Duncan test. The results of this study showed that sawdvst sengon media generally give better effect to the growth and yield of oyster mushroom, while corn cob flour treatment concentration was not known exactly in enhancing the growth and yield of oyster mushroom. Treatment of media accelerate the deployment of mycelium old, when appearing pin head, increasing the number of fruiting bodies in a single clump and increasing the mushroom fruit body weight. Extra flour treatment corncob accelerate as emerging pin head, increasing the number of fruiting bodies in a clump and increase total body weight of mushrooms.

The structures of the condensed tannins from leaf, stem bark and root bark of Acacia confusa were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, and their antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing/antioxidant power (FRAP) assays. The results showed that the condensed tannins from stem bark and root bark include propelargonidin and procyanidin, and the leaf condensed tannins include propelargonidin, procyanidin and prodelphinidin, all with the procyanidin dominating. The condensed tannins had different polymer chain lengths, varying from trimers to undecamers for leaf and root bark and to dodecamers for stem bark. The condensed tannins extracted from the leaf, stem bark and root bark all showed a very good DPPH radical scavenging activity and ferric reducing power.

Natural dyes are environment friendly in nature and cannot cause any harmful effects as is the case with most of the synthetic dyes. Nevertheless, most of the natural dyes exhibited weak interaction between fabric and natural dye, which resulted in poor shade depth and durability problems for cotton fabric. This research work is an endeavor to apply natural dyes in combination with eco-friendly cross-linker to enhance the durability and performance of natural dyes. Moreover, pH of the dyeing solution imparted significant effect on color characteristics of fabrics dyed with acacia dye. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the spatial distribution of root forces in root-permeated soils that are subject to shear. In-situ large shear tests, 1.0 m × 1.0 m × 0.5 m, on plant root systems are carried out. The root system of Leucaena leucocephala (Lam.) (white popinac) and Acacia confusa (Formosa acacia) are used in this study. The axial forces developed in plant roots in soil that is subject to shear rely on the root location and orientation with respect to the shear direction. The majority of the roots in front of the tree stem, with respect to the shear direction, develop compressive forces during the shearing process, as the root orientation is low. Roots on the side of the tree stem tend to develop tensile forces during the shearing process. Most of the measured root forces at the back of the tree stem with respect to the shear direction are in tensile modes. Post-peak root forces continue to develop with increasing shear displacements. The percentage of the maximum mobilized root force in tensile modes during shear in this study reaches to approximately 68% of its ultimate tensile resistance at a shear displacement of 10–25 cm, whereas most of the instrumented data are less than approximately 45%. The maximum mobilized stress level for roots in front of the tree stem during the shearing process is low with respect to the ultimate tensile resistance of the root, and the maximum mobilized stress level for roots on the side and at the back of the tree stem is moderate. This study provides an in-depth look at the root forces developed in a plant root system subjected to shear. [ABSTRACT FROM AUTHOR]

The antioxidant, anti-inflammatory, antivirus, uric acid decreasing, and hepatoprotective activities of Acacia confusa extracts were demonstrated in previous studies. However, there is no scientific evidence concerning the immune-regulatory activity of the heartwood extract of A. confusa. In this study, the effect of a methanolic heartwood extract (MHE) from A. confusa on dendritic cell (DC) activation and function was examined. A. confusa MHE significantly reduced the production of pro-inflammatory cytokine interleukin-6 (IL-6) in lipopolysaccharide (LPS)-stimulated DCs, and the effective concentration (25 μg ml-1) of A. confusa MHE did not affect cell viability. Additionally, the bioactive phytochemical from A. confusa MHE, melanoxetin, was isolated and purified by HPLC. This substance inhibited the production of pro-inflammatory cytokines (tumor necrosis factor-α, IL-6, and IL-12) in LPS-stimulated DC at a concentration of 12.5 μM. Moreover, the expression levels of co-stimulatory molecules such as CD40, CD80, and CD86 also remarkably decreased after treatment with melanoxetin at the same dose. These findings indicate that A. confusa MHE and melanoxetin have excellent immune-suppressive activity and may be potential candidates for further development of natural health supplements. [ABSTRACT FROM AUTHOR]

Heartwood extracts of Acacia confusa (HEAc) were proven to have the capability of ameliorating wood photostability. However, the efficacy of photostability compared with that of commercial photostabilizers was unknown. The aim of this study was to examine whether HEAc can be used as commercial photostabilizers. Comparison was made among commercially available photostabilizers, UV absorber (Eversorb 80, EV80) and hindered amine light stabilizer (Eversorb 93, EV93). Photostability of wood slices soaked in 1, 5 and 10 % HEAc or 1 % commercial photostabilizers (EV80 or EV93) solutions was evaluated. The discoloration of 5 and 10 % HEAc-treated specimens was significantly reduced after UV irradiation. Furthermore, lignin degradation and carbonyl formation were concurrently inhibited by 5 and 10 % HEAc treatments after UV irradiation. Interestingly, 1 % HEAc treatment showed similar effectiveness compared with EV80 treatment, while 5 and 10 % HEAc treatments showed better effectiveness than EV80 treatment. HEAc can absorb UV light and quench radicals; hence, wood photodegradation was consequently prevented. These results revealed that HEAc has great potential to be developed as a natural photostabilizer. [ABSTRACT FROM AUTHOR]

Purpose: Large areas of land have been impacted by acidic mine drainage. These sites could potentially be re-vegetated for growing energy plants. Conventional phytoremediation method may fail because the pH of some mine drainage and contaminated soils can reach 2.0. Thus, it is necessary to screen acid-tolerant plants as pioneers to rehabilitate those severely acidified areas. Materials and methods: In the first phase of this study, seven levels of low pH media were used to estimate the acid-tolerant ranges of three plant species for 1 month. In the second phase, 50 commonly cultured plant species from 17 families, native in Guangdong Province of China or introduced from Australia, were evaluated for acid tolerance at three pH levels which were chosen based on results in the first phase. Results and discussion: We found that Acacia auriculiformis could survive and nodulate at pH ≥2.0, Acacia confusa and Melaleuca armillaris could survive at pH ≥2.5 but A. confusa nodulate at pH >3.5. In the second phase, 12 plant species, in addition to A. auriculiformis, can survive in pH 2.0 media. Conclusions: No family or genus commonality in acid tolerance was found. Two of these tolerant species, i.e., A. auriculiformis and Jatropha carcas, could potentially be planted as an economically and ecologically viable option for acid mine remediation due to their potential function as biofuel feedstock. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to investigate the inhibition mechanisms of light-induced wood radicals by Acacia confusa heartwood extracts (AcE). Wood radical scavenging analysis was determined by ESR spectroscopy. The results obtained demonstrated that wood radicals could be inhibited through UV absorption of AcE. According to results of AcE photooxidation derivative analyses detected by HPLC–DAD, HPLC–MS/MS and FTIR spectroscopy, o-quinones, peroxides and other oxidation derivatives were yielded from flavonols (such as melanoxetin and transilitin) in AcE; okanin (chalcone) might be formed from 7,8,3′,4′-tetrahydroxyflavanone (flavanone); 7,8,3′,4′-tetrahydroxyflavone and 7,3′,4′-trihydroxyflavone (flavones) would transform to flavanone. On the basis of GPC analysis results, proanthocyanidins and derivatives of higher molecular weight might be polymerized from melacacidin (flavan-3,4-diol). Taken together, these results clearly demonstrated that A. confusa heartwood extract can absorb UV light and form photooxidation derivatives. Accordingly, wood radicals induced by UV light were inhibited and consequently wood photodegradation was retarded. [Copyright &y& Elsevier]

Acacia confusa is an indigenous plantation species in Taiwan, and its heartwood has excellent decay resistance capability. The aim of this study is to investigate the resistance mechanisms of heartwood extracts from A. confusa against Laetiporus sulphureus (brown-rot). Results from wood block decay resistance tests indicate that aqueous crude extract and its three soluble fractions can significantly decrease the weight loss of wood blocks caused by L. sulphureus. However, none of the extracts can inhibit the growth of L. sulphureus on agar plate test. The performance of decay resistance from three soluble fractions is consistent with their antioxidant activities (DPPH free radical scavenging activity, reducing power and ferrous ion chelating ability). 3,4-Dihydroxybenzoic acid (3,4-DHBA), the compound present in three soluble fractions, exhibited excellent antioxidant activities and was proven to have excellent decay resistance ability against L. sulphureus. These findings suggest that 3,4-DHBA may be responsible for the inhibition of hydroxyl radical formation from Fenton reaction caused by L. sulphureus. Thus, 3,4-DHBA has good potential to be used as a novel and environmentally benign wood preservative. [ABSTRACT FROM AUTHOR]

Highlights: [•] Antioxidant potency of Acacia confusa root extract was studied for the first time. [•] Nine antioxidant phenolic compounds, including eight flavonoids were isolated. [•] Okanin exhibited the best antioxidant activities. [•] Melacacidin was the most abundant antioxidant. [•] Structure–activity relationships of these antioxidant flavonoids were discussed. [ABSTRACT FROM AUTHOR]

Flavonoids are abundant in the leaves, flowers, branches, bark, and heartwood of Acacia confusa Merr. (Leguminosae), and the extracts have been found to have strong antioxidant activities. Flavonols are the major class of flavonoids found in A. confusa. The full-length gene (designated as AcFLS) contains an open reading frame of 996 nucleotides encoding 331 amino acid residues with a predicted molecular weight of 38 kDa and pI of 5.7. AcFLS mRNAs were abundant in the seedlings leaves and the flowers. Wounding by cutting leaves induced maximum AcFLS mRNA accumulation 6-12 h after treatment. AcFLS could enzymatically transform dihydromyricetin, dihydroquercetin, and naringenin into the flavonols myricetin, quercetin, and kaempferol, respectively. AcFLS could bind these three substrates with similar affinity. [ABSTRACT FROM AUTHOR]

Arabidopsis AtGH9C1 is an endo-b-1,4-glucanase possessing a carbohydrate-binding domain (CBM49). Analysis of AtGH9C1 expression by promoter-reporter GUS, RT-PCR, public transcriptome databases and GFP protein tagging demonstrated a high and selective expression of AtGH9C1 in root hairs and in the endosperm. Expression in root hair cells started prior to bulge formation and continued during hair elongation. AtGH9C1 expression increased with treatments that increase density (ACC) or length (sucrose) of root hairs. Expression in the endosperm extended sequentially to the micropylar, peripheral and chalazal compartments. A mutant with reduced AtGH9C1 expression had a delay in germination and a marked reduction in root hair presence. Complementation of the mutant partially improved both germination and root hair density. Experiments with ectopically expressed AtGH9C1-GFP with and without the CBM49, demonstrated that both forms of the protein are secreted and that CBM49 targets the protein to specific regions of the cell wall, but what makes these regions special is still unknown. The amino acid alignment of angiosperm GH9 genes with C-terminal extensions illustrate that AtGH9C1 belongs to a different clade than its tomato homolog, S1GH9C1. The latter has a CBM49 that was shown to bind crystalline cellulose. We suggest that AtGH9C1 is associated with the weakening of the cell wall during formation and growth of the root hair as well as with the sequential anterior-posterior breakdown of the endosperm cell wall that provides space for the growing embryo. Thus, is likely that the CBM49 of AtGH9C1 recognizes a form of cellulose or glucan polymer that is prevalent in the wall of these specialized tissues and that is different than the one recognized by S1GH9C1. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA), an important chemical signal from roots, causes physiological changes in leaves, including stomata closure and photoprotection. Furthermore, endogenous ABA concentration in leaves and stomatal behavior vary with the species adapted to different water regimes. In this study, Ficus microcarpa, a hemiepiphyte, Salix warburgii, a hygrophyte, and Acacia confusa, a mesophyte, were used to elucidate the effects of leaf detachment on photosystem II (PSII) efficiency under osmotic- and high-light stresses. Results indicate that, under osmotic- and high-light stresses, PSII efficiency of the detached leaves was lower than that of the attached leaves for all three tree species, when compared at the same levels of stomatal resistance and leaf water potential. Exogenous ABA could mitigate the PSII efficiency decrease of detached F. microcarpa leaves under osmotic- and high-light stresses. Yet, the osmotic stress could raise endogenous ABA concentration in the attached, but not in the detached F. microcarpa leaves. In addition, partial root-zone drying exerted a significant effect on stomatal behavior but not on the water status of F. microcarpa leaves. These observations imply that the stronger ability of PSII in the attached leaves of F. microcarpa under osmoticand high-light stresses was probably due to the protective action of ABA from roots. On the contrary, endogenous ABA level of S. warburgii leaves was very low. In addition, partial root-zone drying produced no significant effect on its stomatal behavior. Therefore, PSII in attached S. warburgii leaves was possibly protected from the damaging effects of excess absorbed energy by signals other than ABA, which were transported from the roots. [ABSTRACT FROM AUTHOR]

The polymeric procyanidins extracted from Acacia confusa stem bark were fractionated with a step gradient of water, methanol and acetone on a Sephadex LH-20 column. The antioxidant activity of the collected fractions was investigated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing/antioxidant power (FRAP) assays. All fractions possessed potent antioxidant activity with the highest activity observed for fraction F9. The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and reversed-phase high performance liquid chromatography (RP-HPLC) analyses suggested that the collected fractions consisted primarily of oligomeric and polymeric procyanidins, with different polymer ranges and most abundant polymer size. For each fraction, catechin and epicatechin were present as both terminal and extension units, and epicatechin was the major component in the extended chain. The mean degree of polymerization (mDP) of each fraction differed, ranging from 1.68 (fraction F2) to 17.31 (fraction F11). There was a relationship between antioxidant activity (IC50/DPPH and FRAP) and mDP (R2 DPPH = 0.861, P = 0.006 and R2 FRAP = 0.608, P = 0.038), respectively. However, the highest antioxidant activity of fraction (F9) was not coincident with the maximum mDP of fraction (F11). [ABSTRACT FROM AUTHOR]

Abstract: Chronic hepatitis C virus (HCV) infection continues to be an important cause of morbidity and mortality by chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC) throughout the world. It is of tremendous importance to discover more effective and safer agents to improve the clinical treatment on HCV carriers. Here we report that the n-butanol–methanol extract obtained from Acacia confusa plant, referred as ACSB-M4, exhibited the inhibition of HCV RNA replication in the HCV replicon assay system, with an EC50 value and CC50/EC50 selective index (SI) of 5±0.3μg/ml and >100, respectively. Besides, ACSB-M4 showed antiviral synergy in combination with IFN-α and as HCV protease inhibitor (Telaprevir; VX-950) and polymerase inhibitor (2′-C-methylcytidine; NM-107) by a multiple linear logistic model and isobologram analysis. A complementary approach involving the overexpression of COX-2 protein in ACSB-M4-treated HCV replicon cells was used to evaluate the antiviral action at the molecular level. ACSB-M4 significantly suppressed COX-2 expression in HCV replicon cells. Viral replication was gradually restored if COX-2 was added simultaneously with ACSB-M4, suggesting that the anti-HCV activity of ACSB-M4 was associated with down-regulation of COX-2, which was correlated with the suppression of nuclear factor-kappaB (NF-κB) activation. ACSB-M4 may serve as a potential protective agent for use in the management of patients with chronic HCV infection. [ABSTRACT FROM AUTHOR]

Abstract: This study shows the photo-stabilizing effect of extractives on wood. XPS and FTIR techniques were used to analyze the variations in chemical characteristics on the surfaces of non-extracted and extracted Acacia confusa heartwood after lightfastness test. XPS survey analyses reveal that non-extracted heartwood exhibits a higher O/C ratio than the extracted wood. Furthermore, results from the detailed analysis of C1s indicated that the photo-oxidative derivatives increased in both extracted and non-extracted specimens after lightfastness test. On extracted wood, the derivatives are mainly derived from lignin, whereas extractives are the major component responsible for the generation of derivatives on non-extracted wood surface. After leaching test of UV-irradiated specimens, it was noted that the degradation products were readily removed by water. More water-soluble derivatives were leached out from the extracted wood, although higher lignin content was observed on the non-extracted wood surface. In conclusion, it is shown that photodegradation of A. confusa wood can be retarded by extractives oxidation. [ABSTRACT FROM AUTHOR]

Abstract: A dimeric 70-kDa chymotrypsin inhibitor with substantial N-terminal sequence homology to serine protease inhibitors was isolated from Acacia confusa seeds. The chymotrypsin inhibitor was purified using a protocol that entailed ion exchange chromatography on Q-Sepharose, SP-Sepharose and fast protein liquid chromatography-gel filtration on Superdex 75. The chymotrypsin inhibitor was unadsorbed on both Q-Sepharose and SP-Sepharose. Its chymotrypsin inhibitory activity was stable from pH 3 to 10 and from 0 to 50°C. It exerted antiproliferative activity toward breast cancer MCF-7 cells with an IC50 of 10.7±4.2μM. It inhibited HIV-1 reverse transcriptase with an IC50 of 8±1.5μM. It was devoid of antifungal activity toward a variety of fungal species. The distinctive features of the chymotrypsin inhibitor included dimeric nature, a high molecular mass, lack of trypsin inhibitory activity, highly potent HIV-1 reverse transcriptase inhibitory activity, specific antitumor activity and relatively high pH-stability. [Copyright &y& Elsevier]

Abstract: Acacia confusa Merr. (Leguminosae), a species native to Taiwan, is widely distributed on the hills and lowlands of Taiwan, and has been traditionally used as a medicine. In this study, phytochemicals and antioxidant activities of hot water extracts from A. confusa leaves were investigated for the first time. Among all the fractions from hot water extracts of leaves, the EtOAc-soluble fraction exhibits the best DPPH radical-scavenging activity, superoxide radical-scavenging activity, and reducing power. In addition, a rapid screening method, on-line RP-HPLC-DPPH system, for individual antioxidants in the EtOAc-soluble fraction was developed. Furthermore, following solid phase extraction (SPE) and reverse-phase high-performance liquid chromatography 12 pure phenolic compounds, including five major compounds (gallic acid, (+)-catechin, (−)-epicatechin, myricetin 3-glucopyranoside, and myricetin 3-rhamnopyranoside) were detected using the developed screening method. These results demonstrated that hot water extracts of A. confusa leaves have excellent antioxidant activities and thus have great potential as a source for natural health products. [Copyright &y& Elsevier]

Abstract: Acacia confusa Merr. (Leguminosae), a species native to Taiwan, is widely distributed on the hills and lowlands of Taiwan, and has been traditionally used as a medicine. The hepatoprotective effects of A. confusa bark extract (ACBE) and its active constituent gallic acid were evaluated against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. CCl4-induced hepatic pathological damage and significantly increased the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and malondialdehyde (MDA) in plasma, and cytochrome P4502E1 (CYP2E1) protein expression in hepatic samples, and decreased the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) in erythrocytes. Treatment with ACBE, gallic acid or silymarin could decrease significantly the AST, ALT, and MDA levels in plasma, and CYP2E1 expression in liver tissues, and increase the activities of SOD and GPX in erythrocyte when compared with CCl4-treated group. Liver histopathology also showed that ACBE, gallic acid or silymarin could significantly reduce the incidence of liver lesions induced by CCl4. These results suggested that the ACBE and gallic acid exhibit potent hepatoprotection against CCl4-induced liver damages in rats, and the hepatoprotective effects of ACBE and gallic acid may be due to the modulation of antioxidant enzymes activities and inhibition of lipid peroxidation and CYP2E1 activation. [Copyright &y& Elsevier]

The present study was carried out to evaluate the antioxidant activities of bark extract of Acacia confusa and some of the isolated constituents from its ethyl acetate (EtOAc) fraction in various in vitro systems to gain mechanistic insights. Results from antioxidant assays together with authentic antioxidant standards revealed that EtOAc fraction showed strong superoxide radical scavenging activity, reducing power, and ferrous ion-chelating ability. Following an in vitro antioxidant activity-guided fractionation procedure, 16 constituents including 12 benzoic acids, three cinnamic acids and one lignans were isolated and identified from the EtOAc fraction. We also evaluated the structure–activity relationships of benzoic and cinnamic acid derivatives. Results obtained indicated that the bark extracts and the derived phytochemicals from A. confusa have a great potential to prevent disease caused by the overproduction of radicals and also it might be used as a potential source of natural antioxidant agent. [Copyright &y& Elsevier]

Abstract: The present study showed that the ethanolic extracts from the bark of Acacia confusa exhibited a strong antioxidant activity. Among all the fractions from ethanolic extracts of bark, the EtOAc soluble fraction exhibited the best antioxidant performance. Furthermore, following by CC and HPLC, 11 pure phenolic compounds were isolated and identified from the ethanolic extracts. [Copyright &y& Elsevier]

The article focuses on the scions of the plant Acacia koa Gray. The plant is grafted from the rootstocks of Acacia koa, Acacia mangium, and Acacia confusa with the method of cleft or splice grafts application to every young seedling. Wherein, Acacia koa scion plants at the second true leaf stage of development were joined with the Acacia rootstocks of similar phenology just below the cotyledons.

Two tropical woody species, Acacia confusa Merrill and Litsea glutinosa (Lour.) C.B. Robinson, were grown under controlled conditions in PVC pipes filled with John Innes No. 2 soil. To investigate root distribution, physiological characteristics and hydraulic conductivity, four soil treatments were imposed—well-watered and noncompacted (control), well-watered and compacted; unwatered and noncompacted, and unwatered and compacted. In L. glutinosa, rooting depth and root elongation were severely restricted when soil bulk density increased from around 1.12 to 1.62 g cm−3, whereas soil compaction had little effect on these parameters in A. confusa. As soil drying progressed, root water potential and osmotic potential declined more slowly in L. glutinosa than in A. confusa. Both the soil drying and compaction treatments significantly stimulated the accumulation of root abscisic acid (ABA) in both species. Soil drying damaged the root cell membrane of A. confusa, but had little influence on the root cell membrane of L. glutinosa. Soil drying had a greater effect on root hydraulic conductivity (Lp) in L. glutinosa than in A. confusa, whereas the effect of soil compaction on Lp was less in L. glutinosa than in A. confusa. Soil drying enhanced the effects of soil compaction on root Lp. We conclude that soil drying and compaction have large species-specific effects on the distribution, growth and physiology of roots. The relationships of these root properties to the species' ability to tolerate unfavorable soil conditions were examined. [ABSTRACT FROM AUTHOR]