• Journal of the Korean Wood Science and Technology
• /
• v.48 no.3
• /
• pp.303-314
• /
• 2020

Gambir is a non-wood forest product with a potential of being used as wood adhesive, due to about 33% catechin in it. Meanwhile, catechins and sucrose have not been studied as adhesives. Therefore, basic characteristics of gambir-sucrose adhesives were investigated. In this research, adhesives were prepared by dissolving gambir and sucrose in distilled water, at different blending ratios of the gambir/sucrose such as 100/0, 75/25, 50/50, and 25/75 wt%. Furthermore, gas chromatography-mass spectrometry (GC-MS) was employed to determine the gambir chemical compositions, and Fourier transform-infrared (FTIR) spectroscopy was carried out to identify chemical bonds. Particleboards with a target density of 0.8 g/㎤ were then manufactured by hot-pressing for 10 min at 200℃. The internal bond (IB) strength of particleboard was subsequently measured. Based on the GC-MS analysis, 31.11% of catechin was identified. In addition, the viscosity, density, solid content, and gelation time of the adhesives, and insoluble matter content (IMC) in boiling water were 7.30~33.24 mPa.s, 1.2~1.3 g/㎤, 25.56~28.44%, 73~420 min, and 29.75~62.10%, respectively. Adding sucrose to the adhesive was observed to raise the IMC from 49.05 to 62.10%, at 180℃ and 200℃. FT-IR analysis showed that the gambir absorption peaks occurred at approximately 1620 cm^-1, assigned to the C=O stretching of 5-hydroxymethylfurfural, which tended to increase with the addition of sucrose. The reaction between gambir and sucrose was observed in the form of the dimethylene ether bridge. The 25/75 wt% gambir-sucrose adhesives and 200℃ hot-pressed temperature resulted in the highest IB strength (0.89 MPa), and met the requirement of JIS A5908-2003 type 18. Consequently, the gambir-sucrose adhesive could be used as a particleboard adhesive.

• Journal of the Korean Wood Science and Technology
• /
• v.51 no.3
• /
• pp.183-196
• /
• 2023

Recently, the morphological and molecular features of five stain fungi infecting rubberwood (Hevea brasiliensis), namely Paecilomyces maximus, Paecilomyces formosus, Penicillium crustosum, Paecilomyces lecythidis and Aspergillus chevalieri, have been studied. Prior to this study, the authors revealed that catechin from gambir (Uncaria gambir) could inhibit the growth of the white-rot fungus Schizophyllum commune, and it was important to determine the bioactivity of the aforementioned agent against A. chevalieri. The efficacy of the biocidal agent was examined using a laboratory wooden block test. Rubberwood blocks, 8 mm in thickness, 20 mm in width, and 30 mm in length, were impregnated with catechin solution at concentrations of 6%, 9%, 12%, and 15% (w/v) using the vacuum-pressure method, and their bioactivity was monitored over three weeks through visual and scanning electron microscope assessment of fungal growth as well as the discoloration intensity of the wood samples. The results showed that catechin treatment increased the resistance of wood samples to A. chevalieri. Overall, the higher the catechin concentration, the lower the fungal growth. The lowest fungal growth was observed in the wood samples treated with 12% and 15% catechin (score of 0), demonstrating no discoloration. In contrast, the fungal growth score of the untreated wood samples reached 4, indicating severe discoloration. Catechins appear to be adequate biofungicides against stain fungi in rubberwood.

• Food Science and Preservation
• /
• v.24 no.1
• /
• pp.93-99
• /
• 2017

Collagen synthesis is decreased and matrix metalloproteinase-1 (MMP-1) levels are increased in naturally aged human skin, and these alterations cause changes such as skin wrinkling and decreased elasticity. As a part of our ongoing search for bioactive ingredients, MMP-1 inhibitory and type-1 procollagen synthesis inducing activities of aqueous methanolic extract of manufactured gambir product from Uncaria gambir were investigated in in vitro bioassay systems. In addition, total phenolic contents were quantified using a spectrophotometric method. Among tested samples, 40% MeOH eluate from 80% methanolic extract of manufactured U. gambir using open column chromatography packed with Diaion HP-20 resin showed significant MMP-1 inhibitory activities with an $IC_{50}$ value of $15.6{\pm}1.3{\mu}g/mL$. Furthermore, type-1 procollagen synthesis promoting property of 40% MeOH eluate ($IC_{50}$ value; $6.9{\pm}0.7{\mu}g/mL$) from 80% methanolic extract of manufactured gambir was higher than other eluates. Additionally, the present investigation revealed that 40% MeOH eluate of manufactured gambir product contained a high level of total phenolic compounds. The result suggests a distinct relationship between anti-wrinkle activity and total phenolic contents, and manufactured gambir product could be considered a new effective source of natural bioactive ingredients. Systematic investigation of manufactured gambir product will be performed for further development of its biological properties.

• Food Science and Preservation
• /
• v.23 no.3
• /
• pp.387-392
• /
• 2016

The antioxidant activities of brownish natural dyeing agents, extracted from seven kinds of plants, were tested. Total polyphenol content, DPPH and ABTS radical scavenging activities, and singlet oxygen quenching effect were determined for hot water extracts and floral waters of plants. DPPH and ABTS radical scavenging activites increased with increasing amounts of the extracts from Uncaria gambir R. and Terminalia chebula R. displayed remarkable scavenging effects at concentrations below 0.1 mg/mL, in comparison with the positive control, ascorbic acid. However, antioxidant effects of the floral water, obtained from steam distillation of tested plants, were inefficient at concentration below 0.2 mg/mL. In particular, the natural dyeing agent effectively suppressed singlet oxygen induced by photosensitizer in in vitro assay systems. The concentrations ($IC_{50}$) required to exert 50% of singlet oxygen were 120 and $190{\mu}g/mL$ for hot water extracts from Uncaria gambir R. and Phellinus linteus, respectively. Among all the tested samples, the Uncaria gambir R. and Phellinus linteus extracts contained higher amount of total phenolic contents. The results suggest that naturally occurring dyeing agents are beneficial as natural antioxidants, encouraging further extensive studies.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.7
• /
• pp.966-976
• /
• 2019

Objective: The methane mitigating potential of various plant-based polyphenol sources is known, but effects of combinations have rarely been tested. The aim of the present study was to determine whether binary and 3-way combinations of such phenol sources affect ruminal fermentation less, similar or more intensively than separate applications. Methods: The extracts used were from Acacia mearnsii bark (acacia), Vitis vinifera (grape) seed, Camellia sinensis leaves (green tea), Uncaria gambir leaves (gambier), Vaccinium macrocarpon berries (cranberry), Fagopyrum esculentum seed (buckwheat), and Ginkgo biloba leaves (ginkgo). All extracts were tested using the Hohenheim gas test. This was done alone at 5% of dry matter (DM). Acacia was also combined with all other single extracts at 5% of DM each, and with two other phenol sources (all possible combinations) at 2.5%+2.5% of DM. Results: Methane formation was reduced by 7% to 9% by acacia, grape seed and green tea and, in addition, by most extract combinations with acacia. Grape seed and green tea alone and in combination with acacia also reduced methane proportion of total gas to the same degree. The extracts of buckwheat and gingko were poor in phenols and promoted ruminal fermentation. All treatments except green tea alone lowered ammonia concentration by up to 23%, and the binary combinations were more effective as acacia alone. With three extracts, linear effects were found with total gas and methane formation, while with ammonia and other traits linear effects were rare. Conclusion: The study identified methane and ammonia mitigating potential of various phenolic plant extracts and showed a number of additive and some non-linear effects of combinations of extracts. Further studies, especially in live animals, should concentrate on combinations of extracts from grape seed, green tea leaves Land acacia bark and determine the ideal dosages of such combinations for the purpose of methane mitigation.

• Korean Journal of Food Science and Technology
• /
• v.32 no.4
• /
• pp.949-958
• /
• 2000

Antimicrobial effects of 150 kinds of Korean and 82 kinds of Indonesian plants were investigated to develope natural food preservatives. Extracts of the plants with 70% ethanol were tested their antimicrobial effects against several food spoilage microorganisms, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. Seventeen kinds of Korean and eighteen kinds of Indonesian plants were found relatively effective, of which Myristica fragrans and Melaleuca leucadendra were the most effective, respectively. The major fractions of the two plant extracts showing antimicrobial activity were further purified by solvent fractionation, silicagel column chromatography and preparative HPLC. The purified substances were identified as limonene and caprylic acid in M. fragrans, and ${\alpha}-terpineol$ in M. leucadendra, respectively.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.20 no.1
• /
• pp.187-192
• /
• 2006

Herbal medicines have been utilized to treat a variety of diseases, including cancer. Several species of the family rubiaceae have been reported to have antitumor activity. In this study, we report the cytotoxicity and antitumor activity exhibited dy the methanol extracts prepared from Rubia radix (RRME), Uncaria gambir (UGME) and Oldenlandia diffusa (ODME) (family: Rubiaceae) against human promyleloid leukemia cell line, HL-60. The cytotoxicity of RRME (2~20 ${\mu}g/ml$), UGME (20~200 ${\mu}g/ml$) and ODME (20~200 ${\mu}g/ml$) were assessed dy the MTT reduction assay. IC50 values for RRME, UGME and ODME were 11.0, 99.5 and 106.1 ${\mu}g/ml$, respectively. When the HL-60 cells were treated with RRME (10 ${\mu}g/ml$), UGME (120 ${\mu}g/ml$) and ODME (140 ${\mu}g/ml$) for 24 h, several apoptotic characteristics such as DNA fragmentation and morphologic changes were observed. Furthermore, flow cytometric analysis was peformed to determine the percent of apoptotic cells. The poupulation of sub-G1 hypodiploid cells was increased 37.49% in RRME treatment, 12.49% in UGME treatment and 7.21% in ODME treatment compared with untreated control cells (2.64%). To further confirm apoptotic cell death, we assayed caspase-3, -8 and -9 activities in RRME, UGME and ODME-treated cells. After treatment of RRME, UGME and ODME for 12 h, caspase-3, -8 and -9 activities significantly increased.compared to untreated control cells. These results show that RRME, UGME and ODME induced apoptotic cell death in HL-60 cells and may have a possibility of potential antitumor activities.