Antifungal and antitermitic activities of wood vinegar from Vitex pubescens Vahl

Antifungal and antitermitic activities of wood vinegar produced from Vitex pubescens were evaluated. Three kinds of wood vinegar were produced at three different pyrolysis temperatures, i.e. at 350, 400 and 450 °C. A PDA dilution method was employed to assay antifungal activity of the vinegars with a white-rot fungus Trametes versicolor and a brown-rot fungus Fomitopsis palustris. Termiticidal activity and repellent effect were evaluated by a no-choice test and a choice test with Reticulitermes speratus and Coptotermes formosanus. All wood vinegars exhibited antifungal activity against both fungi. Wood vinegar of 450 °C had the higher activity than those of 400 and 350 °C. It was assumed that acid component contributed to the increase in controlling the growth of fungal. The wood vinegar exhibited antitermite activity to both R. speratus and C. formosanus workers in the no-choice experiment. However, it needed relatively high concentration to obtain the perfect mortality. For instance, the wood vinegar of 10 % concentration was needed to achieve 100 % mortality against C. formosanus, whereas for R. speratus only 3 % of wood vinegar was required. In the direct-choice experiment, wood vinegar had a significantly repellent effect to both termites at the lowest treating concentration of 10 %.     

Development of boards made from oil palm frond II: properties of binderless boards from steam-exploded fibers of oil palm frond

Binderless boards were prepared from steam-exploded fiber of oil palm(Elaeis guineensis Jacq.) frond at six levels of explosion conditions. Their properties were investigated and evaluated. The mechanical properties (i.e., modulus of rupture, modulus of elasticity, and internal bonding strength) of the boards increased linearly with increasing board density as the usual hardboard. The boards made from fibers treated under a steam explosion condition of 25 kgf/cm² (steam pressure) and 5 min (digestion period) exhibited the maximum strength. These boards at a density of 1.2 g/cm³ met the requirement of S-20 grade of JIS A 5905 — 1994 (fiberboard). Thickness swelling of the boards ranged from 6% to 14% under the JIS A 5908 — 1994 (particleboard) test condition and showed no significant changes with increasing board density. The main bonding strength of the board is believed to be due to a ligninfurfural linkage. Considering the chemical components of oil palm frond, which is rich in hemicellulose, there seems to be a good possibility for producing binderless boards using steam-exploded fibers of oil palm frond.This study was presented in part at the 2nd International Wood Science Seminar, Serpong, Indonesia, November 1998     

对棕榈油生产贸易现状及产业发展的思考

自进入21世纪以来,我国已经成为最大的棕榈油进口国,棕榈油的消费量的快速增长使得其已经成为我国植物油供给的重要组成部分.我国不少企业认识到油棕榈产业的良好大战前景,积极投入其中.现结合油棕榈产业规划的相关经验,对全球棕榈油发展现状进行总结,并提出我国油棕榈产业发展的基本思路.     

Isolation and characterization of proline/betaine transporter gene from oil palm

Oil production from oil palm is adversely affected by drought and salt. Under drought and salt stress, proline content increases in oil palm; the mechanism for this is unknown. Here, an 8319-nucleotide sequence including cDNA, genomic DNA and the promoter region of proline transporter gene from oil palm Elaeis guineensis was determined. The transporter gene exhibited high similarity to Bet/ProT genes from several plants, but the highest homology was found with rice ProT1. The exon-intron structure of genomic DNA was unique, and numerous stress-response cis-elements were found in the promoter region. Expression of cDNA EgProT1 in Escherichia coli mutant exhibited uptake activities for glycinebetaine and choline as well as proline. Under salt-stressed conditions, exogenously applied glycinebetaine was taken up into the root more rapidly than the control. These data indicate that oil palm has a unique Pro/T1 gene. Nucleotide sequence data for the cDNA and genomic DNA of proline transporter gene from Elaeis guineensis are available in the DDJB database under accession numbers AB597035 and AB597036, respectively.     

Antifungal activity of essential oils isolated from Egyptian plants against wood decay fungi

The essential oils of eighteen Egyptian plants were extracted by hydrodistillation and their chemical compositions were analyzed by GC-MS. The antifungal activity of the isolated oils was evaluated against two wood decay fungi Hexagonia apiaria and Ganoderma lucidum in vitro. The essential oil of Artemisia monosperma showed the highest inhibitory effect against H. apiaria (EC₅₀ = 31 mg L^?1) and G. lucidum (EC₅₀ = 53 mg L^?1). The results of in vitro tests indicated that the essential oils of Cupressus sempervirens, Citrus limon, Thuja occidentalis, Schinus molle, A. monosperma and Pelargonium graveolens were the most potent inhibitors against both fungi. These six oils caused significant reduction of wood mass loss of Scots pine sapwood after 6 weeks of fungal exposure. The oil of C. limon revealed the highest reduction of wood mass loss caused by H. apiaria, while A. monosperma oil displayed the highest reduction of wood loss caused by G. lucidum. These results support the potential use of essential oils for wood protection against decay fungi.     

Termiticidal activity of wood vinegar, its components and their homologues

The termiticidal activity of wood vinegar, its components, and their homologues have been studied. Three kinds of wood vinegar made from the mixed chips ofCryptomeria japonlca andPseudotsga menziesii (wood vinegar A),Quercus serrata (wood vinegar B), andPinus densiflora (wood vinegar C) exhibited high termiticidal activities againstReticulitermes speratus. Acetic acid, which is the largest content of wood vinegar, exhibited high termiticidal acitivity. The contents of organic fraction of wood vinegars and acetic acid might be responsible for the differences in termiticidal activities among these wood vinegars. The structure and termiticidal activity relations of phenols were studied. Phenol with some substituents revealed higher termiticidal activity than benzene derivatives, which have no hydroxyl group; an ortho substituent of phenol plays an important role in termiticidal activity. It has become apparent that high termiticidal activity cannot be obtained by a phenolic hydroxyl group alone; it can be obtained, however, by some substituents, especially an ortho substituent in addition to a phenolic hydroxyl group. The bulkiness of the substituent at the ortho position participates in termiticidal activity; activity decreases as the size of an ortho substituent increases. It is thought that the interaction at the receptor site of termites is affected by the increased size of the ortho substituent.     

Environment-friendly short-term protection of palm wood against mould and rot fungi

Felled palm trunks are susceptible to fungi as long as their moisture content is above fibre saturation. During this period, palm wood has to be protected against mould and rot fungi. The study was aimed at testing environment-friendly organic acids for their protecting efficiency. Small samples of date palm (Phoenix dactylifera) and oil palm (Elaeis guineensis) wood were treated with weak organic acids and subsequently infected by moulds and wood-decay fungi. Short dipping of the samples in solutions of 5% acetic acid and propionic acid, respectively, protected all samples for two months from colonization by Aspergillus niger, Penicillium sp., Cladosporium sp. and by a natural infection. Boric acid (4%) used in practice for protection was ineffective. Decay tests with the white-rot fungus Pleurotus ostreatus, the brown-rot species Coniophora puteana and the soft-rot fungus Chaetomium globosum showed that both acids prevented most samples from fungal colonization for three weeks and reduced the decay considerably during two months.     

Immunomodulatory activities of fractions from hot aqueous extract of wood from Clausena excavata

The effects of fractions from hot aqueous extract, acetone extract and the folklore preparation of Clausena excavata were studied on mouse splenocyte proliferation. The fractions of hot aqueous and acetone extracts were found to be the most active. On the contrary, the fractions from the crude folklore preparation resulted less active. This result could partly explain the popularity of this plant in folk medicine as a remedy for cancer and HIV patients in the eastern part of Thailand.     

Headspace solid‐phase microextraction gas chromatography–mass spectrometry for the detection of volatile organic compounds released from Ganoderma boninense and oil palm wood

Basal stem rot disease caused by the white‐rot fungus Ganoderma boninense is a major threat to the oil palm industry, and hence, the ability to detect infections at an early stage of development is desired. In this study, a headspace solid‐phase microextraction (HS‐SPME) method coupled with gas chromatography–mass spectrometry (GC‐MS) was employed to analyse the volatile organic compounds (VOCs) released from G. boninense cultures and infected oil palm wood. We examined VOCs released from three types of samples: G. boninense mycelium, oil palm wood and oil palm wood colonized by G. boninense. This preliminary study led to the tentative identification of 57 VOCs, including alcohols, alkanes, volatile acids, ketones, aldehydes, esters, sesquiterpenes and polycyclic aromatic hydrocarbon groups. Aliphatic compounds with eight‐carbon atoms, such as 1‐octen‐3‐ol, 3‐octanone, 1‐octanol and (E)‐2‐octenal, were the most abundant constituents of the Ganoderma samples, whereas furfural and hexanal were the major compounds detected in the oil palm wood samples. Chemometric analyses using cluster heat maps and principal component analyses were used to discriminate between the VOC profiles. The results indicated that the novel method described here could be used to detect Ganoderma disease and, more generally, for chemoecological studies of plant–pathogen interactions.     

Manufacture and properties of oil palm frond cement-bonded board

This study was designed to reveal the role of the cement/wood ratio in a hydration test of wood-cement mixtures. The compatibility of oil palm (Elaeis guineensis Jacq) fronds-cement mixtures was tested in the hydration test, with the addition of magnesium chloride as an accelerator at different water/cement ratios. To prove the findings on the hydration behavior of components, the cement-bonded boards were manufactured using a conventional cold-pressing method at different cement/wood ratios. Results indicated that the optimum weight ration of cement/wood increased with decreasing wood powder size based on the equal specific surface area ratio of cement/wood in the hydration test and board manufacturing. The addition of magnesium chloride improved the compatibility of oil palm fronds with cement; the compatibility factor (C _A) increased by more than 90% with the addition of 5% magnesium chloride. TheC _A factor increased proportionally with a higher magnesium chloride content and a higher water/ cement ratio. The addition of magnesium chloride also enhanced the cement hydration and ultimate board strength properties. However, the addition of 5% magnesium chloride did not improve the properties of boards sufficiently at a cement/wood ratio of 2.21.0.     

植物精油对木材霉变菌的抑菌效力研究

【目的】植物精油是一类安全环保且具有抑菌特性的天然产物,在木材霉变防治领域的应用潜力很大。开展植物精油对我国常见木材霉菌及变色菌的综合抑菌效力的研究,可为天然环保型木材霉变防治剂的开发提供重要依据。【方法】配制经植物精油修正的马铃薯葡萄糖琼脂培养基,通过评价霉变菌在培养基中的生长状况,对比分析19种植物精油对6种木材霉变菌的抑菌效力。【结果】在体积分数为0.05%的条件下,19种植物精油对黑曲霉Aspergillus niger、桔青霉Penicillam citrinum、绿色木霉Trichoderma viride、可可球二孢Botryodiplodia theobromae、串珠镰刀菌Fusarium moniliforme和链格孢霉Alternaria alternata的抑菌效力分别为0~100%、0~100%、0~100%、0~100%、11%~100%和20%~100%。聚类分析表明,肉桂、丁香花和百里香精油的综合抑菌效力最高,在体积分数0.05%的条件下对6种霉变菌的抑菌效力均达到100%,而尤加利、甜橙和松树精油的综合抑菌效力最低。相关分析表明,植物精油对6种霉变菌的抑菌效力之间均表现出显著相关性(P=0.01),其Pearson相关系数为0.777~0.959。【结论】不同植物精油的抑菌效力之间表现出较大差异,肉桂、丁香花和百里香精油是可以用于木材霉变防治的较优品种。     

Property gradients in oil palm trunk (<Emphasis Type="Italic">Elaeis guineensis</Emphasis>)

Since the structure of oil palm wood varies dramatically, the property gradients of oil palm wood within a trunk are of great interest. In this study, the physical (density, water uptake and swelling in the radial direction) and mechanical properties (bending modulus of elasticity and strength, compressive modulus of elasticity and strength in the direction parallel to the fiber, compressive strength in the direction perpendicular to the fiber and shear strength in the direction parallel to the fiber) of oil palm wood for a whole trunk were examined. The water uptake, compressive strength in the direction perpendicular to the fiber, shear strength in the direction parallel to the fiber, bending modulus of elasticity and strength and compressive modulus of elasticity and strength in the direction parallel to the fiber appeared to be independent of trunk height but tended to be related to the relative distance from surface or density by a single master curve. However, the swelling in the radial direction of the oil palm wood was not correlated with the relative distance from the surface, trunk height or density. Finally, property map of oil palm wood for a cross section at any height was prepared for practical use.     

Evaluation of biological activities of extracts from 22 African tropical wood species

Heartwoods of 22 African tropical wood species were extracted with methanol and the contents of total phenolic compounds in these extracts were measured. Three bioassays were conducted to evaluate the antioxidant activity, tyrosinase inhibitory activity, and antifungal activity of the methanol extracts. The results indicated that the extracts from 13 species exhibited high antioxidant potential, and their inhibitory concentrations that caused 50% scavenging of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (IC₅₀) were less than 10 μg/ml. The crude extract from Cylicodiscus gabunensis showed the highest antioxidant activity, and was even higher than that of (+)-catechin, which is known as a potent antioxidant. There was a good correlation between the antioxidant activity and the content of total phenolic compounds, indicating that phenolic compounds played a predominant role in the antioxidant property of the wood extracts. Among all 22 species, only 1 species, Milicia excelsa, contained extractives that showed very high tyrosinase inhibitory activity. The extracts from 9 species showed high antifungal activity. No consistent relationship was observed between the tyrosinase inhibitory activity or antifungal activity and the content of total phenolics in the extracts. Part of this article was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, August 2006     

Antimicrobial activities of essential oil from Artemisiae argyi leaves

Introduction Artemisia species, widespread throughout the world, are important medicinal plants, which are receiving phytochemical attention due to the biological and chemical diversities (Tan et al. 1998). Artemisias (Compositae) are one of the most popu…     

Tradeoffs between hydraulic and mechanical stress responses of mature Norway spruce trunk wood

We tested the effects of growth characteristics and basic density on hydraulic and mechanical properties of mature Norway spruce (Picea abies (L.) Karst.) wood from six 24-year-old clones, grown on two sites in southern Sweden differing in water availability. Hydraulic parameters assessed were specific hydraulic conductivity at full saturation (ks100) and vulnerability to cavitation (Psi50), mechanical parameters included bending strength (sigma b), modulus of elasticity (MOE), compression strength (sigma a) and Young's modulus (E). Basic density, diameter at breast height, tree height, and hydraulic and mechanical parameters varied considerably among clones. Clonal means of hydraulic and mechanical properties were strongly related to basic density and to growth parameters across sites, especially to diameter at breast height. Compared with stem wood of slower growing clones, stem wood of rapidly growing clones had significantly lower basic density, lower sigma b, MOE, sigma a and E, was more vulnerable to cavitation, but had higher ks100. Basic density was negatively correlated to Psi50 and ks100. We therefore found a tradeoff between Psi50 and ks100. Clones with high basic density had significantly lower hydraulic vulnerability, but also lower hydraulic conductivity at full saturation and thus less rapid growth than clones with low basic density. This tradeoff involved a negative relationship between Psi50 and sigma b as well as MOE, and between ks100 and sigma b, MOE and sigma a. Basic density and Psi50 showed no site-specific differences, but tree height, diameter at breast height, ks100 and mechanical strength and stiffness were significantly lower at the drier site. Basic density had no influence on the site-dependent differences in hydraulic and mechanical properties, but was strongly negatively related to diameter at breast height. Selecting for growth may thus lead not only to a reduction in mechanical strength and stiffness but also to a reduction in hydraulic safety.     

Hygroscopicity of wood impregnated with linseed oil

Summary The reduction in hygroscopicity as spruce wood is impregnated with linseed oil may be accounted for using a molecular exclusion model. On the basis of the model, each linseed oil molecule appears to displace 90 water molecules and occupy 6 hydrogen bonding sites in the wood.Dr. Allen R. Sharp, Associate Professor of Physics at the University of New Brunswick and Dr. Christen Skaar, Professor of Wood Physics at Virginia Polytechnic Institute and State University freely gave essential advice and encouragement during this work. Graphical depiction of the molecular displacement model (Fig. 1) was suggested by Dr. Skaar. Much of the experimental work was carried out by Mr. Wu-Rong Perng, Scientific Technician in Wood Science and Mrs. Monica Snow, Instructor in Wood Science at the University of New Brunswick     

Antifungal activity of the volatile oil of Eucalyptus citriodora

The volatile oil extracted from the leaves of Eucalyptus citriodora showed a wide spectrum of antifungal activity.     

Neuropharmacological activities of fruit essential oil from Litsea cubeba Persoon

Litsea cubeba (Lauraceae) is woody plant endemic to Taiwan that is traditionally used as a spice. In the current study, several behavioral analyses were performed to evaluate the neuropharmacological activity of the essential fruit oil of L. cubeba in ICR mice. Oral administration of 100, 300 and 500?mg/kg of L. cubeba fruit oil significantly prolonged pentobarbitone-induced mouse sleeping time by 20.0, 110.8, and 159.6?%, respectively. In addition, after administration of L. cubeba oil, mice significantly increased the time spent in the open arms and number of entries into the open arms of an elevated plus maze compared to saline-treated mice suggesting that L. cubeba oil has anxiolytic activity. A tail-flick test conducted after treatment of mice with 500?mg/kg L. cubeba fruit oil also suggested that this oil has potent analgetic activity. According to GC/MS analyses, the essential fruit oil of L. cubeba oil consists of 23 compounds. The main components are geranial (37.16?%), neral (28.29?%), and d-limonene (22.90?%). We conclude that L. cubeba oil has a potent effect on the central nervous system of mice.     

木醋对几种小浆果扦插繁殖的影响

为了解决小浆果扦插繁殖中生根率及成活率低等问题,将木醋应用于小浆果的嫩枝扦插与硬枝扦插中,研究其对小浆果扦插的影响。采用不同浓度的木醋浸泡及扦插后定期喷施的方法,对5种不同的插穗进行了试验研究。结果表明:木醋能够缩短各种插穗的生根时间,对嫩枝扦插的效果优于硬枝扦插。嫩枝扦插中能缩短生根最长时间分别为蓝莓7 d,树莓和黑加仑5 d,蓝靛果6 d,枸杞4 d。而硬枝扦插中能缩短生根最长时间分别为蓝莓和蓝靛果1 d、树莓和枸杞2 d,黑加仑4 d。嫩枝扦插中,蓝莓木醋100倍液处理、树莓和枸杞木醋200和300倍液处理,蓝靛果木醋300倍液处理、黑加仑木醋200倍液处理在缩短生根时间上效果最显著。硬枝扦插中,蓝莓、黑加仑和枸杞的木醋300倍液处理效果最好,树莓木醋200和300倍液处理表现相同,为最好,蓝靛果木醋200倍液处理最好。从生根综合质量来看,木醋的喷施改变了扦插的生根情况,只是不同插穗种类,不同扦插方式,最适宜的木醋浓度不同。从插穗染菌情况看,无论是嫩枝扦插还是硬枝扦插,木醋均能降低插穗的染菌率。木醋100倍液处理抑菌效果最好,其次是木醋200和300倍液处理。基本是浓度越大,抑菌效果越好。综上所述,木醋对试验中的几种小浆果的扦插具有一定的促进作用。无论是在缩短生根时间,还是对插穗生根综合质量的提高及降低染菌率等方面木醋均有明显的促进作用。可以将木醋应用于小浆果的扦插中,只是在应用时要注意浓度的选择。