Short notes: A Chemotaxonomic Study of the Resins from Three Dipterocarp Species (Shorea macrophylla, Shorea pinanga, and Shorea hopeifolia)

A chemotaxonomic study on the resins of Shorea macrophylla, Shorea pinanga, and Shorea hopeifolia was conducted. The dichloromethane extracts were separated into neutral and acidic fractions and then analyzed using GC-MS. The neutral fraction analysis revealed that spathulenol, caryophyllene oxide, aromadendrene oxide, and isoaromadendrene epoxide were the major constituents in all three species. Furthermore, the main compound in the neutral fraction of Shorea hopeifolia was isocaryophyllene which was undetected in the other two species. The major constituent of the acidic fraction of the three species was hexadecanoic acid, while pentadecanoic acid was the major constituent in the acidic fraction of Shorea pinanga and Shorea hopeifolia. Therefore, the presence of sesquiterpenes as well as fatty acids in S. macrophylla, S. pinanga, and S. hopeifolia was discovered to be a marker for identifying the genus Shorea.

Extractive contents of the juvenile stemwood and bark of teak

Teak wood is used at the juvenile stage due to short-rotation, therefore, this study aims to describe the extractive content of stem, bark, branch, and twig parts of the wood as value-added chemicals from secondary metabolites. Moreover, the main stems comprise of sapwood, heartwood, and bark while the branch and twig are made of sapwood together with bark. In this study, the sample trees were 6 and 8 years old with three replications from clonal superior teak wood and were extracted using n-hexane, methanol, and hot water as the solvents. The average of n-hexane, methanol, hot water, and total extractives ranged from 0.49 to 2.77%, 2.27 to 17.76%, 0.65 to 7.47%, and 5.96 to 25.40%, respectively. Furthermore, the total phenolic content from soluble n-hexane and methanol extracts ranged from 162.16 to 295.24 mg GAE/g, while the total soluble polysaccharides ranged from 166.28 to 423.97 mg GluE/g. The results showed that the 8-year-samples had higher values in methanol extractive content (MEC) and lower in hot-water extractive content (HWEC) than the 6-year-old trees. In addition, the bark together with sapwood in branch and twig parts had higher concentrations of MEC and total extractive content (TEC) compared to the main stems. For radial direction, MEC, HWEC, and TEC levels were greater in bark than in other parts. The branch and twig parts also had higher phenolic concentrations compared to the main stem at the base part. Meanwhile, the sapwood at the branch and twig parts have higher total soluble polysaccharide concentration compared to the main stem.

Bonding ability of sengon wood treated with natural extracts

Wood preservation technology has been using a lot of synthetic preservatives for a long time. However, some disadvantages have been recorded such as environment quality degradation and killing more untargeted wood destroying organism than targeted one. Recently environment quality maintenance has been required causing a significant change in general wood processing technology and wood preservation paradigm. In terms of wood preservatives has changed from synthetic to natural wood preservatives application. Sengon is the fast growing wood species chosen in Indonesia to fulfill national and international wood demand. Unfortunately this wood species is class V of wood durability and has to be treated with preservatives. Glued wood products such as plywood, lamination, particleboard and fiberboard use low durability wood such as sengon. The objective of this research is to know the adhesion strength of sengon wood after treatment with the natural preservatives. This research was conducted by wood adhesion block method. The fast growing sengon plantation wood was chosen since this type of sengon wood was classified as low grade of wood quality (Class V). This type of wood had high portion of sapwood which was susceptible to wood destroying organism and absence of natural preservatives. The sources of natural wood preservative chosen were gadung tubers, pulai bark and kumis kucing leaves, while the extraction methods were hot water and alcohol toluene. The wood adhesive used was bio-industrial PVAc. Extraction procedure of natural wood preservatives followed ASTM D1110-1984 and D-1107-1996-2013. The procured naturally extracts was processed to obtain extract concentration 1 gram per liter. Wood preservative application used padding method on the wood surface by 0; 1; 2 and 3 application times. Each padding method was processed was applied after the former one was air dried. Wood adhesion test followed block type with with glue spread and cold press system. Compression shear test of block samples followed British Standard (1957). The research results showed that adhesion strength was highly significantly affected by single factor of padding application. Padding application exerted a negative correlation to adhesion strength. Increased natural preservatives treatment (padding application) on the wood surface resulted lower adhesion strength. The average sengon wood adhesion strength of control, 1; 2 and 3 padding application were 5.10; 3.00; 2.22 and 1.05 MPa respectively. The average wood failure were 69.20; 66.71; 62.12 and 45.83% respectively.

Chemical characteristics of Eucalyptus pellita with heart rot

Eucalyptus pellita has been posited as a primary raw material in Indonesia due to its fast growth. In some areas, however, trees with heart rot were found. Thus, the wood with heart rot was analysed chemically both in sound (sapwood, outer heartwood, inner heartwood) and degraded parts (heart rot-affected wood/HRAW). The results revealed that there was a different trend in the wood chemical composition between bottom and centre parts. In bottom parts, wood with bigger diameter of heart rot, the slight changes in polysaccharides and lignin amounts was observed in HRAW compared to sound wood parts. On the contrary, comparatively high lignin and low polysaccharide levels in HRAW were measured in centre parts. HRAW was also characterized with high content of inorganic materials and high pH values but low in extractive content, mostly ethanol soluble extractives or its polar fraction. Increasing of phenolic contents was more pronounced in HRAW of lower part than that of upper of the stem. The difference trend of chemical composition between bottom and centre parts suggesting the cause of heart rot could be several wood degraders.

The contents of phenolics and cell wall component of Eucalyptus pellita F. Muell stemwood and bark

Eucalyptus pellita is the fast-growing species which is being developed for a raw material of pulp and paper in Indonesia. The aim of this research was to evaluate the total phenolics (TPC) and flavanols contents (TFC) in the stemwood and bark parts from four individual trees. Another purpose was to determine its cell wall contents. Wood and bark materials in two vertical positions (bottom and top) were successively extracted using dichloromethane, ethanol and hot water as the solvents. Axial factor affected significantly in the values of hot water extract, TPC, and TFC but no significantly affected the cell wall component contents. The ethanol extract levels in the heartwood part was the significantly highest. It is noticed that the heartwood part had high levels of the TPC and TFC and low level in lignin content. From this experiment, the comparatively high levels of TPC and TFC in the heartwood indicate the potential antioxidative properties that should be explored in the future. Further, the low content of Klason lignin in the heartwood part would be an advantage for pulp production.

Antioxidant activity of Swietenia macrophylla king bark extracts

This study investigated the antioxidant activity from the methanol (MeOH) soluble extract of the inner and outer bark of Swietenia macrophylla. The MeOH soluble extracts were fractionated into ethyl acetate (EtOAc) soluble and insoluble. The antioxidant activity was conducted by DPPH (1,1-diphenyl-2-picrylhydrazyl) method and the phenolic compounds were detected by GC-MS. The levels of total phenolic content of soluble and insoluble fraction of EtOAc of outer bark were higher than in inner bark, while total flavonoid content showed opposite results. The crude methanol extract and its EtOAc soluble fraction of outer bark showed a higher level of antioxidant activity. The GC-MS analysis detected higher levels of fatty acids and alcohols of 87.12% than phenolic compounds of 12.17% in the inner bark, while the outer bark showed the opposite pattern with phenolic compounds of 82.65% than fatty acids of 8.43%. A strong correlation was demonstrated between total phenolic content and antioxidant activity.