• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.861-868
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• 2020

The use of polyphenol extracts from radiata pine (Pinus radiata) bark as raw materials for bio-foams was investigated along with the optimal NaOH extraction conditions. The targeted yield of alkaline extracts was 60%, and the targeted pH was 11 to 12. The radiata pine bark was composed of 70% of a 1% NaOH extract, which contained mainly polyphenols, such as proanthocyanidin (PA). As the particle size of the bark decreased, the yield of the 1% NaOH extracts increased from 57 to 87%. A range of NaOH concentrations, liquor ratios, and extraction times were explored to establish an economic polyphenol extraction method. More than 60% of the alkaline extract was extracted, and the pH of the extract was approximately 12 when the optimum extraction conditions were employed, i.e., a liquor to bark ratio of 5:1, a NaOH dosage of 17 to 18% based on the bark weight, and a 1 h extraction time. Following neutralization of the alkaline extract, structural analysis indicated severe structural changes in the PA during the alkaline extraction. Because the alkaline extract was barely soluble in the solvent used for the structural analyses, it is assumed that chemical modification is required to increase the solubility of the alkaline extract for the production of bio-foams.

• Journal of the Korean Wood Science and Technology
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• v.47 no.4
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• pp.498-508
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• 2019

This study was carried out to investigate the potential of Korean red pine (Pinus densiflora) inner bark extracts as an antidiabetic agent. The ethyl acetate soluble fraction of the bark extracts was chromatographed on a Sephadex LH-20 column to yield five compounds, which structures were elucidated by NMR spectroscopy. The isolated compounds were (+)-catehin, (-)-epicatechin, taxifolin, taxifolin-3'-O-${\beta}$-D-(+)-glucose and $\tilde{n}$-courmaric acid. The antidiabetic activity of the different fractions, including the crude extracts and isolated compounds, was evaluated by ${\beta}$-cells insulin secretion and glucose uptake in skeletal muscle cells. The insulin secretion was 128% for taxifolin at $25{\mu}g/mL$. However, the other samples had no effect on this test. For the glucose uptake activity assay, $1{\mu}M$ insulin and 2 mM metformin were used as controls. Both the crude extract and taxifolin showed relatively low activity values, but the other samples yielded glucose uptake values over 260%. ${\rho}$-courmaric acid showed the highest uptake (270%). The results confirmed that Korean red pine extracts may be used as a hypoglycemic agent.

• Journal of the Korean Wood Science and Technology
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• v.24 no.4
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• pp.1-6
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• 1996

Extracts from bark have been studied with a view to producing water-proof wood adhesives. Lately many softwoods, such as radiata pine from New Zealand and larch from Siberia, Russia, have been imported and utilized, and their residual barks would be expecting as potential raw materials for something useful chemicals. The great effort toward utilization of bark extractives as a chemical feedstock has been made on a worldwide level. However few report has been done for the utilization of tree bark extractives in Korea. Hot-water extracts were prepared from barks of Japanese larch(Larix leptolepis). Siberian larch(Larix gmelinii) and Radiata pine(Pinus radiata). The effect of various factors, such as particle size, liquor ratio, extraction temperature, and reaction time, on the extractive yields was discussed. Particle sizes affected the hot-water extractives: the finer the particle size, the higher extractives and extract efficiency. Higher temperature and higher liquor ratio were more effective. Extractives from Japanese larch were relatively less than those from Siberian larch and Radiata pine barks. Formaldehyde precipitates was the highest in extractives of Radiata pine barks. It could be concluded that Siberian larch bark was the best raw material for tannin adhesives, because its extractive yield was higher than those of the other barks.

• Journal of the Korean Wood Science and Technology
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• v.47 no.1
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• pp.80-89
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• 2019

Pine barks are important biomass resources because they are utilised in the production of pine wood and rosins. However, no chemical study has been conducted on the hydrophilic status of pine barks in Indonesia. This aim of this study is to explore the hydrophilic extracts of the barks from six Pinus species (P. elliotii, P. caribeae, P. oocarpa, P. merkusii P. montezumae, and P. insularis). The hydrophilics of pine barks were analysed using gas chromatography-mass spectrometry. The presence of polyphenol contents in the ethanol extracts obtained from the barks of six Pinus species was determined using the tannin-formaldehyde method, Folin-Cioucalteu assay, and vanillin-HCl assay. The ethanol and hot water soluble extractives derived from inner barks were higher in quantity when compared to those derived from the outer bark samples. The polyphenol measurement showed that the highest value of total phenol content was derived from the outer bark of P. montezumae whereas those of the total phenol and tannin- formaldehyde contents were derived from the inner and outer barks of P. oocarpa. GC-MS analysis revealed that nitrogenous compounds are dominant constituents in the inner and outer barks of the six species, followed by sugars and monophenolics, respectively.

• Journal of Life Science
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• v.20 no.7
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• pp.1047-1053
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• 2010

This study was conducted to evaluate the effects of dietary Korean red pine bark extract as an antibiotic replacement on cecum microflora, immune functions, blood lipids, carcass characteristics, and growth performance in broiler chickens. There were four treatment groups: a control group, an antibiotic group, and two treatment groups receiving 65 and 80 ppm Korean red pine bark extract. Growth performance, carcass weight, dressing percentage, and breast and thigh muscle weight of the broiler chickens fed 80 ppm of red pine bark extract was higher than the broilers of the control group and the antibiotic group. Abdominal fat was lower in both groups of broiler chickens fed red pine bark extract, but the growth of immune organs such as the thymus, spleen, and bursa of Fabricius was significantly higher in the group that received a diet supplemented with 80 ppm red pine bark extract than in the control group and antibiotic group. Concentrations of triacylglyceride and total cholesterol were significantly lower in both groups that received red pine bark extract when compared to the control group and the antibiotic group. The concentration of serum IgG was significantly higher in the 80 ppm red pine bark extract group than in the control group and the antibiotic group. The numbers of Bifidobacterium and Lactobacillus in the cecum digesta were significantly increased, while the numbers of Escherichia coli and Salmonella were significantly reduced in the group that received 80 ppm red pine bark extract when compared to the control group and the antibiotic group. These results suggest that the a diet with 80 ppm Korean red pine bark extract as a replacement for antibiotics improve the cecum microflora, immune functions, blood lipids, carcass characteristics and growth performance of broiler chickens.

• Journal of the Korean Wood Science and Technology
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• v.25 no.1
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• pp.23-27
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• 1997

Alkali-soluble extracts were prepared from barks of Japanese larch(Larix leptolepis). Siberian larch(Larix gmelineii) and Radiata pine(Pinus radiata) The effect of various factors, such as particle size, liquor ratio, extraction temperature, and reaction time, on the extracts yield was investigated. Particle sizes affected the alkali-soluble extracts; the finer the particle size, the higher extracts and extract efficiency. High temperature and high liquor ratio were more effective. In the range of 0.25% to 1% NaOH concentration, alkali extracts were increased with the increasing alkali concentration. However, extract yields were leveled off above 0.5% alkali concentration. Extractions with NaHCO3 were almost equivalent to those of NaOH extraction. 1% NaOH and 1% NaHCO3 resulted in the highest yields of alkaline extracts. Extracts from Japanese larch were lower than those from Siberian larch and Radiata pine barks. Siberian larch bark was the best raw material for tannin adhesives, because its extractive yield was higher than those of the other barks. Concerning pH of alkaline media during extraction, small increases of the extract yields were resulted at range of pH 7 to pH 9, while a large increases from pH 9.0 to pH 12. This phenomenon is attributed to higher alkalinity.

• Asian Journal of Turfgrass Science
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• v.12 no.4
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• pp.203-210
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• 1998

Environmental concerns arising from synthetic herbicides in plant management systems have led to an interest in plant-derived compounds as natural herbicides. Inhibitory effects of compounds extracted with 50% methanol from corn (Zea mays L.) and pine (Pinus densiflora L.) were evaluated on large crabgrass (Digitaria sanguinalis (L.) Scop.), annual bluegrass Poa annua L.), radish (Raphanus sativus L.), and perennial ryegrass (Lolium perenne L.) The aqueous extracts inhibited seed germination and had postemergence activity on the four species. The stability of biological activity of corn grain, stover, and root extracts was not affected by heating to $135^{\circ}C$ or freezing/thawing treatments when applied at levels above 0.25kg m(sup)-2 based on dry weights of powders before extraction. Heating reduced the activity of pine litter and bark extracts at all levels except the highest application level but had little effect on pine needle extracts.

• Journal of Pharmaceutical Investigation
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• v.37 no.6
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• pp.359-364
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• 2007

Pine bark extract is well-known as a very powerful antioxidant, anti-inflammatory, and antibiotic material. French maritime pine bark extract ($Pycnogenol^{(R)}$) of Horphag Research has monopolized the world market over 30 years. Korean red pine bark extract ($Pinexol^{(R)}$) was first manufactured by the patent technology of NutraPharm in Korea in 2006. Feasibility of topical gel and patch formulations of Pinexol was systematically investigated by evaluating the skin absorption of catechin as a reference compound. In vitro hairless mouse skin absorption of catechin from gel formulation was higher than that from patches. However, significant amount of catechin was also deposited inside the skin from patch formulations, which were dependent on the types of pressure sensitive adhesives. Thus, it seems to be feasible to control the topical delivery of Pinexol by using both gel and patch formulations, and be necessary to conduct further systematic investigation.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.424-430
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• 2006

Low molecular weight polyphenols were isolated from hot water extracts of radiata pine (Pinus radiata) bark using a Sephadex LH-20 column and characterized by $^1H$ and $^{13}C$ NMR, UV, FT-IR, and GC-MS analyses. Major compounds isolated and identified were protocatechuic acid, trans-taxifolin, and quercetin. Trans-taxifolin, an important intermediate in biosynthetic route of proanthocyanidin (PA), was isolated in large quantities and indicates that PA is a major component of radiata pine bark. Small amounts of polyphenols were identified by GC-MS analysis. The presence of p-hydroxybenzoic acid, vanillic acid, protocatechuic acid, cis- and trans-feruic acid, p-coumaric acid, trans-caffeic acid, (-)-epicatechin, (+)-catechin, trans- and cis-taxifolin, (+)-gallocatechin, and quercetin was confirmed by comparison of mass fragmentation patterns and retention times (RT) with authentic samples. In addition, the presence of astringenin, astringenin glycoside, trans- and cis-leucodelphinidin was strongly assumed from characteristic mass fragment ions due to their conjugated structure and retro Diels-Alder reaction, and also from biosynthetic route of PA. GC-MS analysis allowed us to detect small amounts of phenolic acids and flavonoids and eventually discriminate trans- and cis-configuration in the identified polyphenols.

• Journal of the Korean Wood Science and Technology
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• v.26 no.1
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• pp.29-37
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• 1998

Alkali-soluble extracts were prepared from medium-sized barks of Radiata pine(Pinus radiata). There are difficulties in the production of extracts with uniform quality and in the preparation of adhesives with suitable viscosity. Ultrafiltration using an Amicon cell was subjected to fractionate extracts according to molecular sizes in order to overcome the above problem. The filtration efficiency was studied by using thin channel filtration systems. Adhesive manufacturing was also examined. Removal of particles greater than 0.45m from the extracts increased both filtration speed (flux) and yields of solids in the filtrates. Ultrafiltration with PM 10 membrane was very effective to fractionate and concentrate the extracts. Stiasny precipitates from the filtrates obtained by PM 10 membrane were very lower than that(83%) of the retentates. This ultrafiltration method was efficient for obtaining high yield purified phenolic compounds(mainly polyflavanoids) and thus important for preparing wood adhesives from barks. The extracts were shown excessive high viscosities at the concentrations required for adhesive formulation, but this high viscosity and short gelation time was reduced by lowering pH of the extracts and addition of urea. The highest bonding strength of plywoods(340g/$m^2$ of adhesive spreads) was achieved with adhesive formulated by 100parts of mixed alkali extracts and urea(70/30,w/w), 10parts of p-formaldehyde and 3.5parts of wheat flour at pH 6, and by hot pressing at the conditions of 12kg/$cm^2$ at $120^{\circ}C$ for 10 minutes.