Variability in the Natural Termite Resistance of Plantation Teak Wood and Its Relations with Wood Extractive Content and Color Properties

Property of natural termite resistance of teak (Tectona grandis)wood signifies one of its most important characteristics. With the purpose of understanding the variation in such resistance, four teak trees in the form of trunk (stem) from Randublatung , Central Java were randomly selected, and each wood portion sampled in radial and axial direction. Extractive content and color properties of the teak wood were also measured and correlated with properties of its natural termite resistance. Bioassay test was conducted by no-choice feeding method using Reticulitermes speratus Kolbe termites. The extractive contents were determined by successive extraction using n-hexane, ethyl acetate, and methanol, respectively. Color properties were measured with the CIELAB system. Results showed that antitermitic activity of the teak wood was affected by radial and axial position in the corresponding tree. The wood from middle part of the trees in axial direction exhibited the most resistant to termites (mean mass loss = 1- 4 mg ), while in radial direction the sapwood exhibited the least resistance ( greatest mass loss), and moving inward to the near-pith heartwood the resistance tended to decrease somewhat (slight increase of mass loss). Heartwood and sapwood part differed significantly in ethyl acetate and methanol- soluble extractive contents. Apparently, the greater the ethyl-acetate-soluble extractives (EEC) then the higher the termite resistant (lower mass loss), and conversely the greater the methanol- soluble extractive (MEC) then the lower the termite resistant ( greater mass loss). The brightness index (L*) and redness index (a*) varied significantly in radial direction, however, no significant variation was found in color properties within the heartwood. No strong degree correlation was measured between the mass loss due to termite activity and extractive content parameters. In both heartwood and sapwood, a significant negative correlation (r = -0.50) was found between the mass loss and redness (a*), while correspondingly a significant positive correlation (r = +0.54) occurred between brightness and mass loss. These occurring phenomena strongly suggested that the red colored teak wood was brought about by the moderately polar EEC (e.g. tannin, quinone, and other polyphenol) that inflicted teak-wood resistance against termite (lower mass loss), while the bright-colored teak wood was due to the highly polar MEC (e.g sugar and other soluble carbohydrate) which were conversely responsible for lowering termite resistance ( greater mass loss)

Chemical variation of five natural extracts by non-polar solvent

Chemical compounds of wood preservation from plants vary and are not known specific to the species. Chemical analysis of plants is responsible to ensure active compound in natural extracts wood treatment. There are many sources of natural extracts found in Indonesia that were explored for wood preservatives chemicals. They are bark of acacia and alstonia, leaves of orthosiphon and azardirachta and Dioscorea tubers. The present study was aimed at investigating the variation of the chemical constituent of natural extracts material of wood preservative through GC-MS analysis. Five natural extract sources were acacia bark (Acacia spp.), pulai bark (Alstonia scholaris), kumis kucing leaves (Orthosiphon spp.), mimba leaves (Azardirachta indica), and gadung tubers (Dioscorea spp.). Two non-polar solvents, i.e., n-hexane and petroleum ether were used for five natural source extractions following ASTM soxhlet extraction. The research showed that triterpene and fatty acid derivatives were the major compounds present in five natural extracts. They were lupeol; 7,22-Ergostadienone; Lup-20(29)-en-3-one; Lup-20(29)-en-3-ol, acetate, (3.beta.)-; urs-12-en-3-one; ethanol,2,2-diethoxy-; stigmasta-5,22-dien-3-ol, acetate,(3.beta.)-; 5H-3,5a-Epoxynaphth(2,1-c)oxepin, dodecahydro-3,8,8,11a-tetramethyl-; linoleic acid; naphthalene, 1-methyl-. These compounds have been assigned as the possibly responsible to against termites or fungi

Reduction in Toxicity of Tectoquinone Against Reticulitermes Speratus Kolbe Termites

The cause of low toxicity against Reticulitermes speratus Kolbe termite species of teakwood under natural condition was investigated. Anti-termite test was conducted to evaluate the effectivity of four major components (tectoquinone, deoxylapachol, tecomaquinone, and squalene) of ethanol-benzene extracts in the teak heartwood. Tectoquinone exhibited both strong toxicity and antifeedancy as well as it was far superior to other components. The strength reduction of tectoquinone bioactivity is assumed due to interaction with other major components. As squalene was found in considerable amounts or 1.8 to 13.1 times as high as the tectoquinone concentration in woods, termite feeding was set to the mixtures of tectoquinone and squalene in various ratios (1:1, 1:5, 1:10, and 1:20). It was revealed that squalene addition could decrease the termite mortality 15% to 44% from its initial value (tectoquinone only). On the other hand, the mixtures reduced mass loss due to termite attacks only to a small degree

Properties of Included Phloem in Teakwood

In some areas of Indonesia, the heartwood of teak tree (Tectona grandis L.f.) contains included phloem, which is categorized as defects. This paper characterized the colour and chemical properties of such abnormal wood. Three selected trees from Perhutani plantation, Randublatung region, were assessed. The heartwood colour properties were measured by CIELAB system. Result showed that the included phloem-containing heartwood (IPHW) was darker (L*), but less red (a*) and yellow (b*) compared to the adjacent normal heartwood (NHW). The lignin and ash contents were not significantly different in the wood radial direction. In contrast, the level of extractive contents were significantly different between sapwood and heartwood. The amount of ethanol-benzene extractive and solubility in 1% NaOH in the IPHW region were significantly higher than that in normal tissues. The analysis of extractive components using gas chromatography-mass spectrometry showed that the deoxylapachol and lapachol was highly marked in the IPWH region. The obtained results suggest that napthaquinone compounds were related to the protection against wood-destroying organisme attack

Quinone Contents in Teak Heartwood Isolated by Cold Extraction

Sampling by increment borer along with wood extraction by cold soaking would be useful for large sample size and if the destructive sampling is undesirable. This work aimed to evaluate the reliability of cold extraction by methanol and acetone to extract the quinone compounds of teak heartwood compared to the conventional soxhlet extraction by ethanol-benzene. Another purpose of this work was to find out the intra-tree variability of quinone compound around the outer heartwood parts (8 angles, 16 points). On the basis of the yield of ethanol-benzene extracts in 6 trees, cold extraction could remove the extracts of 37-66% by methanol and 23-61% by acetone. By correlaton analysis, considerable degree of correlations (r>0.9) were calculated between soxhlet and cold extraction in the contents of deoxylapachol, lapachol, tectoquinone. With regard to intra-tree variation quinones, wide level ranges were observed in all compounds by judging the coefficient of variation, except for tectol. Therefore, it is suggested that the sampling in the tangential direction in a single tree should be taken at 3 points separated by at least 90 degrees to avoid the bias in the individual components. The variation of quinone total amounts, however, showed comparatively low (18%) of coefficient of variation

Antifungal Activities of Certain Components of Teak Wood Extractives

The present research was aimed to evaluate the antifungal activities of teak (Tectona grandis) extracts and their components against Trametes versicolor, Fomitopsis palustris, Rhizopus oryzae, Cladosporium cladosporioides, and Chaetomium globosum. In this study, wood meal of 72 years old teak heartwood was successively refluxed with n-hexane, ethyl acetate and methanol. Bioassay-guided investigation by measuring the growth rate of each fungus on potato dextrose agar (PDA) medium led to the fractionation of n-hexane soluble extract. Column chromatographic fractionations resulted in the isolation of tectoquinone, deoxylapachol, squalene and an unknown compound (C1). The n-hexane and EtOAc extracts were potent mycelial growth inhibitors for R. oryzae (76-78%) and C. cladosporioides (65-73%), while MeOH extract had higher antifungal activities against both T. versicolor (80.2%) and C. globosum (83.3%). In the compound levels, the results were varied, in which deoxylapachol could inhibit all fungi species except for the C. globosum, while tecquinone merely deterred the growth of R. oryzae (58.9%). Squalene and C1 were growth inhibitors to C. cladosporioides (50-63%)

The Natural Termite Resistance of Teak Wood Grown in Community Forest

The objective of this study was to evaluate the antitermitic activities of young teak wood through wood extracts and wood blocks samples method. Correlation between extractive content and its antitermitic properties was also studied. The disc samples from the bottom part of the five 8 years old and four 22 years old trees were sawn and samples from outer sapwood, inner sapwood, outer heartwood, and inner heartwood were prepared. Extractive contents were determined through secluded cold extraction of the wood meal using n-hexane, ethyl acetate (EtOAc) and methanol (MeOH). Force-feeding method using Reticultermes speratus Kolbe termites was used for termite resistance test. A significant interaction between tree age and radial direction factors existed with regards to the n-hexane and EtOAc extractive content. The tree age factor did not affect the mass loss levels in the extract samples. The most susceptible to termites was the sapwood of the 8 years old trees. The n-hexane and ethyl acetate extracts of the inner and outer heartwood significantly influenced the mortality rate, but in contrary to that of tree age. The EtOAc extracts of the outer heartwood was the most active antitermite. The extractive content of heartwood did not correlate to antitermite properties