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The isolation of actinomycetes from wood in ground contact and the sea
1980 - IRG/WP 1110
M S Cavalcante, R A Eaton


Environmentally more acceptable solvents
1979 - IRG/WP 3131
The subject of this paper is hydrocarbon solvents with particular reference to the cyclo-aliphatic or naphthene-rich, grades which are now available. The specialised low aromatic high boiling petroleum fractions are also discussed.
A M Cumbers


The mechanism of leaching of copper-chrome-arsenic preservatives from treated timber in saline waters
1976 - IRG/WP 374
A mechanism for the leaching of copper-chrome-arsenic preservatives is proposed on the basis of theoretical calculations and experimental studies using timber subjected to a range of water types of different ionic compositions. Complex formation by copper (II) and chromium (III) with chloride and hydroxide ions is shown to affect the leaching rate. Of even greater importance is the salt effect on the activity coefficients. The various complexes formed at different pH values are discussed. Two minima are observed in the plot of copper leaching versus water salinity; these are attributed to the presence of the copper fixation compounds Cu2(OH)AsO4 and Cu3(AsO4)2. At low salinities NaCl is shown to have a coagulating effect on the copper fixation compounds, reducing their solubility, whereas at higher salinities complex formation dominates. With chromium the coagulation effect is not observed and leaching increases with increasing salinity. Loss of arsenic is shown to lag behind that of copper and chromium and is related to the chromium excess in the preservative formula: the greater the excess, the longer the delay in arsenic loss. The suggested mechanism adequately explains the experimental results.
J Irvine, S-E Dahlgren


Effect of Cinnamomum kanehirae Extractives on the Compositions of the Fermentation Broth of Antrodia cinnamomea
2007 - IRG/WP 07-10632
The fruiting body of Antrodia cinnamomea, called niu-chang-chih, is well known and highly prized in Taiwan as a folk medicine. This fungus is endemic to Taiwan and the growth of which is restricted to the inner heartwood cavities of another endemic tree species, Cinnamomum kanehirae. The fungal basidiomes have been used for treating food and drug poisoning, diarrhea, abdominal pain, hypertension, itchy skin and cancer. The purpose of this study was to investigate the effect of C. kanekirae extractives on the fungal mycelium production and the spore germination. The heartwood was extracted using 70% ethanol, and then liquid-liquid partitions using n-hexane, ethyl acetate, n-butanol and distilled water were carried out respectively. The effects of treating the fermentation broths with C. kanehirae extractives on the fungal biomass, antioxidant scavenging activity using 1, 1-diphyenyl-2-picrylhydrazyl (DPPH) were examined, and the compositions of the fermentation broth were monitored using high-performance liquid chromatography analysis. The results indicate that C. kanehirae extractives treated fungal broths had higher growth promotional effect on their biomass then that of the control (0.0313 g). The n-hexane soluable fraction treated mycelia showed the greatest dry mass (0.0480 g), followed by ethyl acetate soluable fraction (0.0333 g). The addition of crude extract increased the spore germination activity from 8.1 x 106 cfu/ml to 1.1 x 107 cfu/ml. The n-butanol soluble fraction showed the best spore germination activity of 1.3 x 107 cfu/ml. The active fungal ingredient, dehydroeburicoic acid, was found to increase with the addition of C. kanehirae extractive fractions according to the HPLC analysis. The C. kanehirae extractives were effective DPPH free radical scavengers which masked the antioxidant effect of the fungal broth.
Ruo-Yun Yeh, Yuan-Min Shen , Shang-Tzen Chang


Chemical compositions and anti-termite activities of essential oils from Gabonese Canarium schweinfurthii Engl, Dacryodes buettneri Engl and Aucoumea klaineana Pierre wood resins.
2017 - IRG/WP 17-10895
Essential oil extract from resins of Canarium schweinfurthii, Dacryodes buettneri and Aucoumea klaineana woods from Cap Esterias and Oyem areas, Gabon, were prepared by Clevenger - steam distillation. The chemical compositions of these respective essential oils were analyzed by a Gas Chromatography coupled with Mass Spectrometry (GC-MS). Although monoterpenes were the main constituents of the three essential oils, each wood resins had a various essential oil yield after steam distillation process [6,92% (A. klaineana), 4,20% (C. schweinfurthii) and 13,19% (D. buettneri)] and their respective chemical compositions were slightly different. It results that monoterpenes, as α –pinene, o-cymene, alpha-phellandrene and D-limonene form the major constituents of terpenoides and phenylpropanoïdes compounds which are the most active substances against termite activity. The anti-termite activities of the three essential oils were evaluated, performing no-choice tests. 70 μL of each essential oil diluted in acetone with mass ratios of 50:50 and 25:75 [essential oil: acetone] were impregnated on Whatman papers and exposed to termite (Reticulitermes flavipes). Essential oil from Canarium schweinfurthii resin showed the strongest inhibitory activity against the termite with 100% mortality after 1 day at 50:50 and 25:75 concentrations followed by Aucoumea klaineana resin with the 100% mortality after 3 days at 50:50 and 25:75 concentrations. Finally, essential oil from Dacryodes buettneri resin showed the lowest termite resistance with 48.34 % and 58.34% mortalities after 14 days at 50:50 and 25:75 concentrations, respectively. The number of chemical components from each essential oil and their respective quantity, determined by GC-MS, are related to their anti-termite activity level.
Chemical compositions and anti-termite activities of essential oils from Gabonese Canarium schweinfurthii Engl, Dacryodes buettneri Engl and Aucoumea klaineana Pierre wood resins.


Natural durability of four Tunisian Eucalyptus wood species and their respective compositions in extractives
2019 - IRG/WP 19-10942
In the 50’s, Tunisia government introduced more than 11 Eucalyptus wood species. Eucalyptus species were planted in Tunisia in different arboreta throughout the country for close observation and adaptation to climate and soil. These fast-growing wood species were mainly used as fire wood, for the production of mine wood and to fight against the erosion. These tree species were adapted themselves very well to the Tunisian climate. Now, they tend to become invasive wood species which need to be economically valued. Past study showed that these Tunisian Eucalyptus have great technological properties allowing us to be used as wooden material. However, there is wide variation in heartwood natural durability between eucalypt species. The evaluation of wood durability enables the definition of reliable parameters to predict the service life of wood-based products.This study aimed to evaluate the wood deterioration of four North Tunisian fast-growing eucalypts species (Eucalyptus maidenii, Eucalyptus saligna, Eucalyptus camaldulensis and Eucalyptus gomphocephala) exposed to basidiomycetes (Coniophora puteana and Trametes versicolor) and termites (Reticulitermes flavipes) attacks. Among the four Eucalyptus woods, Eucalyptus gomphocephala presents the highest decay and termite resistance. In addition, it results that the four Eucalyptus wood species are classified as very durable against fungi degradation (Durability class 1) and durable against termite attacks (Visual rating 1), expect for the Eucalyptus saligna which is classified as sensible against termites (Visual rating 3). These natural durability variations according to the wood species have been explained by extractives GC-MS analyses. The natural durability of Eucalyptus seems to be mainly caused by extractives, and a wide range of compounds are involved. But, it appears that it is mostly governed by gallic acid, fatty acid glycerides, fatty acid esters, phenolic compounds, sitosterol, catechin and quercetin.To conclude, Eucalyptus maidenii, Eucalyptus saligna, Eucalyptus camaldulensis and Eucalyptus gomphocephala woods could be used as material sources to improve the economy of the wood sector in Tunisia
S Ben Ayed, M T Elaieb, S Dumarçay, B De Freitas Homen De Faria, M-F Thévenon, P Gerardin, K Candelier