Heart Wood Research Articles

Characterization of water states and pore size distribution in Beijing poplar using nuclear magnetic resonance techniques

ABSTRACT This study employs nuclear magnetic resonance (NMR) techniques to elucidate the water states and pore size distribution within Beijing poplar (Populus beijingensis W. Y. Hsu) across various temperatures. By analyzing the variation in moisture content (MC) at different freezing temperatures, the proportion and distribution of cell wall pores were determined using the NMR Cryoporometry (NMR-C) method. The results show approximately 60% of the pores in both the heartwood (HW) and sapwood (SW) of Beijing poplar have diameters were 1.5 nm, while the proportion of pores with diameters greater than 4.6 nm was less than 10%. Moreover, the MC of both more freely bound water (C-water) and OH bound water (B-water) is observed to decrease exponentially with decreasing temperature. B-water in Beijing poplar is found to maintain a higher MC than C-water across the temperature range from −3 to −60°C, indicating greater resistance to freezing. The findings of this study contribute to a comprehensive understanding of water states in Beijing poplar. Also the pore size distribution of Beijing poplar provides reference data for the selection of wood chemical modification groups.

Diabetes Warriors from Heart Wood: Unveiling Dalbergin and Isoliquiritigenin from Dalbergia latifolia as Potential Antidiabetic Agents in-vitro and in-vivo.

Diabetes mellitus is a serious and complex metabolic disorder characterized by hyperglycemia. In recent years natural products has gained much more interest by researchers as alternative sources for diabetes treatment. Though many potential agents are identified so far but their clinical utility is limited because of their adverse effects. Therefore, there is a keen interest in discovering natural compounds to treat diabetes efficiently with less side effects. Dalbergia latifolia is well explored because of its diverse pharmacological activities including diabetes. Therefore, the present research work aimed to identify and isolate the potential antidiabetic agents from the heart wood of Dalbergia latifolia. We successfully extracted DGN and ISG from the heartwood and evaluated their antidiabetic potential both in-vivo and in-vitro. Alpha amylase activity inhibition of ISG and DGN was found to be 99.05 ± 8.54% (IC50 = 0.6025 µg/mL) and 84.68 ± 5.2% (IC50 = 0.0216 µg/mL) respectively. Glucose uptake assay revealed DGN (158%) promoted maximum uptake than ISG (77%) over control. In vivo anti diabetic activity was evaluated by inducing diabetes in SD rats with the help of HFD and STZ (35 mg/kg body weight). After the continuous administration of DGN (5 mg/kg, 10 mg/kg) and ISG (5 mg/kg, 10 mg/kg) for 14 days, we observed the reduction in the blood glucose levels, body weight, total cholesterol, low density lipoprotein, very low-density lipoprotein, blood urea, serum creatinine, serum glutamate oxaloacetic transaminase, serum glutamate pyruvate transaminase and alkaline phosphatase levels than vehicle group indicates the potency of ISG and DGN against diabetes.

Physiological, Biochemical, and Molecular Analyses Reveal Dark Heartwood Formation Mechanism in Acacia melanoxylon.

Acacia melanoxylon is highly valued for its commercial applications, with the heartwood exhibiting a range of colors from dark to light among its various clones. The underlying mechanisms contributing to this color variation, however, have not been fully elucidated. In an effort to understand the factors that influence the development of dark heartwood, a comparative analysis was conducted on the microstructure, substance composition, differential gene expression, and metabolite profiles in the sapwood (SW), transition zone (TZ), and heartwood (HW) of two distinct clones, SR14 and SR25. A microscopic examination revealed that heartwood color variations are associated with an increased substance content within the ray parenchyma cells. A substance analysis indicated that the levels of starches, sugars, and lignin were more abundant in SP compared to HW, while the concentrations of phenols, flavonoids, and terpenoids were found to be higher in HW than in SP. Notably, the dark heartwood of the SR25 clone exhibited greater quantities of phenols and flavonoids compared to the SR14 clone, suggesting that these compounds are pivotal to the color distinction of the heartwood. An integrated analysis of transcriptome and metabolomics data uncovered a significant accumulation of sinapyl alcohol, sinapoyl aldehyde, hesperetin, 2', 3, 4, 4', 6'-peptahydroxychalcone 4'-O-glucoside, homoeriodictyol, and (2S)-liquiritigenin in the heartwood of SR25, which correlates with the up-regulated expression of CCRs (evm.TU.Chr3.1751, evm.TU.Chr4.654_667, evm.TU.Chr4.675, evm.TU.Chr4.699, and evm.TU.Chr4.704), COMTs (evm.TU.Chr13.3082, evm.TU.Chr13.3086, and evm.TU.Chr7.1411), CADs (evm.TU.Chr10.2175, evm.TU.Chr1.3453, and evm.TU.Chr8.1600), and HCTs (evm.TU.Chr4.1122, evm.TU.Chr4.1123, evm.TU.Chr8.1758, and evm.TU.Chr9.2960) in the TZ of A. melanoxylon. Furthermore, a marked differential expression of transcription factors (TFs), including MYBs, AP2/ERFs, bHLHs, bZIPs, C2H2s, and WRKYs, were observed to be closely linked to the phenols and flavonoids metabolites, highlighting the potential role of multiple TFs in regulating the biosynthesis of these metabolites and, consequently, influencing the color variation in the heartwood. This study facilitates molecular breeding for the accumulation of metabolites influencing the heartwood color in A. melanoxylon, and offers new insights into the molecular mechanisms underlying heartwood formation in woody plants.

A review on ecology, distribution, phytochemistry, and pharmacological properties of the medicinally important plant Pterocarpus santalinus L. (Red sanders)

Pterocarpus santalinus L., commonly known as Red sanders, belongs to the family Fabaceae. The plant is well-known for its distinctive wood, which has a stunning color, a delicate appearance, and exceptional technical features. The natural dye santalin, which is produced by the red wood, is used to color foodstuffs and pharmaceutical formulations. The decoction made from the heartwood is given numerous therapeutic characteristics in the ancient system of medicine. It has been used to induce vomiting as well as treat ulcers, mental disorders, and eye illnesses. It is known that the heartwood of Red sander trees has diaphoretic, aphrodisiac, anti-pyretic, anti-inflammatory, anti-helminthic, hemorrhage, and dysentery-preventing properties. Additionally, it has served as a cooling agent. It has been claimed that an ethanol extract of stem bark has anti-hyperglycemic properties. Various studies on the phytochemistry of stem bark extracts in ethanol extracts showed the presence of tannins, phenols, alkaloids, glycosides, flavonoids, and triterpenoids, as well as saponins. Isoflavone glucosides and two anti-tumor lignans, savinin, and calocedrin, are found in the heart wood. However, despite numerous claims of pharmacological activity, the species has not been thoroughly investigated. The current article emphasizes the phytochemistry, pharmacological potential, and applications of P. santalinus.

A Comparative Analysis of Phytochemicals, Metal Ions, Volatile Metabolites in Heart Wood, Stem Bark and Leaves of Salix alba L. along with in Vitro Antioxidant, Antacid, Antimicrobial Activities for Sake of Environment Conservation by Substitution of Stem Bark With Leaf.

The genus of Salix is used in food, medicine and nutraceuticals, and standardized by using the single marker compound Salicin only. Stem bark is the official part used for the preparation of various drugs, nutraceuticals and food products, which may lead to overexploitation and damage of tree. There is need to search substitution of the stem bark with leaf of Salix alba L. (SA), which is yet not reported. Comparative phytochemicals viz. Salicin, Procyanidin B1 and Catechin were quantified in the various parts of SA viz. heart wood (SA-HW), stem bark (SA-SB) and leaves (SA-L) of Salix alba L.by using newly developed HPLC method. It was observed that SA-HW and SA-L contained far better amount of Salicin, Procyanidin B and Catechin as compared to SA-SB (SA-HW~SA-L≫SA-SB). Essential and toxic metal ions of all three parts were analysed using newly developed ICP-OES method, where SA-L were founded as a rich source of micronutrients and essential metal ions as compared to SA-SB and SA-HW. GC-MS analysis has shown the presence of fatty acids and volatile compounds. The observed TPC and TFC values for all three parts were ranged from 2.69 to 32.30 mg GAE/g of wt. and 37.57 to 220.76 mg QCE/g of wt. respectively. In DPPH assay the IC50 values of SA-SB, SA-HW, and SA-L were 1.09 (±0.02), 5.42 (±0.08), and 8.82 (±0.10) mg/mL, respectively. The order of antibacterial activities against E. coli, S. aureus, P. aeruginosa, and B. subtilis strains was SA-L>SA-HW>SA-SB with strong antibacterial activities against S. aureus, and B. subtilis strains. The antacid activities order was SA-L>SA-SB>SA-HW. The leaves of SA have shown significant source of nutrients, phytochemicals and medicinal properties than SA-HW and SA-SB. The leaves of SA may be considered as substitute of stem bark to save the environment or to avoid over exploitation, but after the complete pharmacological and toxicological studies.

Age of heartwood initiation in trunks of young Pinus sylvestris L. trees in the taiga zone

Summary This work is part of a project investigating the heartwood formation process in Scots pine. Despite the economic and ecological importance of pine heartwood (HW), the process of its formation in many respects remains poorly understood. Scientists believe that HW formation in Scots pine begins at 9–20 years, however, systematic studies of HW initiation age in this species have not previously been conducted. Samples were collected from 105 P. sylvestris trees aged 10 to 25 years, growing in the middle and northern taiga subzones, as well as on the border of the northern taiga subzone with the tundra. Samples were taken at the trunk base according to a single technique and processed using two biochemical (peroxidase activity, pinosylvin presence) and two anatomical markers (presence of extractives on the tracheid pit membranes, nuclei disappearance) characterizing different events during HW formation. Biochemical markers showed an overestimation in the number of HW annual rings compared with HW determination based on anatomical criteria by 1–3 years, on average. Attempts to detect peroxidase activity showed a negative result in the inner sapwood annual ring, while detectable pinosylvin accumulation occurred in the transition zone (TZ). We have detected for the first time true HW (without living cells) in Scots pine samples with a cambial age (CA) of 15–17 years. The number of growth rings in TZ and HW in young trees depended on growth conditions. These results are important for understanding the mechanisms of HW formation and developing realistic models of this process, including changing climate conditions.

Acute Toxicity, Sub-Chronic Toxicity and Identification of Anti-Inflammatory Compounds in Pterocarpus osun Heart Wood

Acute Toxicity, Sub-Chronic Toxicity and Identification of Anti-Inflammatory Compounds in Pterocarpus osun Heart Wood

Effects of succinic acid impregnation on physical properties of sapwood and heartwood from plantation-grown short-rotation teak

The aim of this study was to improve the properties of 15-year-old short rotation teak wood using a succinic acid (SA) treatment without excessively increasing the weight gain. The samples were classified as sapwood (SW) and heartwood (HW). Samples were immersed in 10% concentration SA solutions (w/w), followed by vacuuming at -50 kPa for 30 minutes, and applying 7 M Pa of pressure for 2 hours. They were then analysed for specific gravity (SGs), dimensional stability, including tangential/radial ratio (T/R Ratio) and water absorption (WA), weight percent gain (WPG), chemical uptake (CU) and void volume filled (WF). Our results showed that SGs increased in treated SW and HW by 2.33% and 1.23%, respectively, as compared to the untreated wood (0.60 and 0.66). The increase in SGs was the result of SA penetration into wood cell walls. The WPG and CU values increased slightly to 5.54% and 0.87 g cm−3 for SW and 3.46% and 0.62 g cm−3 for HW, respectively. The greater increase of SGs in treated SW is due to a greater ease of treatability in SW than HW. The T/R ratio of treated HW decreased by 29.34% from the initial T/R ratio, whereas SW remained unchanged. The WA of treated SW and HW decreased by 42.67% and 55.46%, respectively compared to untreated wood. Treated wood performed better on dimensional stability, especially in terms of T/R ratio and WA values for HW. Our results show that the impregnation of short rotation teak wood with SA provides a significant increase on dimensional stability with a negligible increase in weight gain.

Inorganic component in oak waterlogged archaeological wood and volcanic lake compartments

Abstract. Waterlogged archaeological wood (WAW) is a rare and precious organic material that can hold outstanding cultural values. In order to protect WAW for the next generations, this material must be accurately characterised to set its proper conservation, storage and exhibition conditions in museum environments. In this study, the mineral content found in WAW retrieved in a volcanic lake was investigated by analysing wood ash through scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (SEM-EDS). This micro-destructive approach was coupled with morphological studies carried out through optical microscopy. SEM-EDS was also performed on the WAW and surrounding sediment to study the possible relationship between the mineral composition and the wood degradation state. The analysis revealed that calcium was the most abundant element in all poles, with weight percentages ranging between 24 % and 42 %. This element was more represented in heartwood (HW) than sapwood (SW). In sapwood the second most abundant element was arsenic. Sulfur, iron and potassium were present in all the analysed samples as well. Arsenic was also detected in the sediments; it was particularly concentrated in the samples taken near archaeological wood. The presence of this element can be linked to the volcanic origin of the lake, and its high concentration points to bioaccumulation processes induced by bacteria (erosion bacteria and sulfate-reducing bacteria) and biogeochemical processes favouring precipitation of insoluble compounds. The present work is the first investigation of the mineral content in archaeological wood establishing a contingent relationship with the surrounding volcanic lake sediments.

Effect of the Fungus Neoscylitiadium dimidiatum Penz. Reduction of Dry Weight and Specific Weight of Sapwood and Heartwood of the Trunks of Populus and Eucalyptus Trees

The study was carried out in the Forest Diseases Laboratory, Department of Forest Sciences, College of Agriculture and Forestry, University of Al Mosul. During the academic year 2021-2022, the Sakla wood is available in the wood stores in the city of Mosul. The study aimed at the effect of decay fungi on some local commercial woods, including populus and Eucalyptus The results of the field survey of wood stores in the city of Mosul showed that most of the wood was infected with brown rot fungus. As the severity of the infection varied in different proportions, the percentage of infection of populus wood columns was 75%, and the percentage of infection of Eucalyptus wood columns was 40%. The fungus Neoscylitiadium dimidiatum penz. caused a decrease in the dry weight of populus wood and Eucalyptus columns from the first month of incubation and continued gradually until the fifth month As the percentage of loss in the fifth month was 4.41% for the populus poles, and the percentage of loss was 3.33% for the Eucalyptus poles. The increase in the losses in the weight of the sap wood continued during the incubation stages and to a greater degree than the increase in the loss percentages in the heart wood.

Pharmacological, Phytochemistry and Ethnomedicinal profiles of Osyris quadripartita Salz. Ex Decne.: A Critical Review

Osyris quadripartita Salz. ex Decne. (Santalaceae), prominently known as African sandalwood, is one of the most seasoned and most valuable sources of natural fragrance with immense medicinal and commercial significance. O quadripartita has been grown in Africa and Indian sub- continents from the ancient times and esteemed all over the world for its tonic, and the aromatic oils are used in different products for manufacturing expensive perfumes, rare soaps, quality lotions, and sweet-smelling candles. Leaf stem bark and African shoe heart wood the essential oil derived from African sandalwood has been used in various traditional and tribal systems of medicine, like Ayurveda, Siddha, Folk and Unani medicine, in the treatment and counteraction of a great many sicknesses. It is utilized to treat different illnesses, including helminth contaminations, leishmaniases like infection, irregularities, kidney sickness, scavenge, sterile/perfuming, eye torment, cool, anaphylactic shock, epilepsy, circumcision wounds, toothache, tonsillitis, stomach agony, and pee issues. The flexible restorative and medical services significance of sandalwood is ascribed to its rich essential oil of phytochemicals, especially sesquiterpenes. African sandalwood, recently utilized for its ancestral modern purposes, is presently acquiring consideration for its helpful as well as food and nutraceutical utilizes. An intensive bibliographic examination was done by dissecting overall acknowledged logical data sets such as Google scholar, Publons, Sci-Finder, Pub Med, Scopus, Web of Science, Research Gate, perceived reference books, and UGC Care listed as well as non-listed international journals. Current pharmacological examinations have shown a great many pharmacological activities, going from antimicrobial to anti-cancer. No huge poisonousness has been demonstrated by African sandalwood essential oil and its singular constituents; in any case, further concentrate on compound constituents and their components in showing specific natural exercises is expected to comprehend the full phytochemical profile and the complex pharmacological impacts of this plant. The expanded business abuse of African sandalwood and low efficiency of this huge restorative plant have raised worries over its preservation and efficiency upgrade through current instruments and procedures. The complete survey examines conventional purposes, ancestral purposes, ethnopharmacology, phytochemistry, and biological activities of African sandalwood to unveil its restorative and modern worth and distinguish holes requiring future exploration.

High-Quality RNA Extraction and Evaluation of Reference Genes for qPCR Assay of <i>Pinus sylvestris</i> L. Trunk Tissues

Scots pine (Pinus sylvestris L.) is a species of tree with heartwood (HW), which is forming during aging of sapwood (SW). Due to clear-cut border between SW and HW P. sylvestris should be used as a model woody plant for studying patterns of HW formation. Currently, molecular genetic methods are used to study the processes of trunk tissues formation in woody plants often. A feature of trunk tissues of coniferous trees is a high content of secondary metabolites, a low content of nucleic acids, and potential partial degradation of RNA. In this work we discuss the choice of most successful method for extraction a high-quality RNA for real-time PCR (RT-PCR) in P. sylvestris trunk tissues along the radial vector “conductive phloem/cambial zone – differentiating xylem – exterior part of SW (1–2 annual rings) – interior part of SW (1–2 annual rings afore transition zone (TZ)) – TZ (2 annual rings afore HW)” for reproducible RT-PCR data. The expression stability of six potential reference genes (Actin1, α-Tubulin, β-Tubulin, Ef1a, GAPDH, UBQ) was assessed in all describe tissues. Differences in expression levels of target genes are shown by data normalization using reference genes with different stability of expression.

Integrated Transcriptomic, Metabolomic, and Physiological Analyses Reveal New Insights into Fragrance Formation in the Heartwood of Phoebe hui.

Phoebe hui is an extremely valuable tree that is the main source of the fragrant golden-thread nanmu wood. Although the fragrance of wood has been investigated in several trees, the potential substances and gene regulation mechanisms that are involved in fragrance formation are poorly understood. Here, three radial tissues, sapwood (SW), heartwood (HW), and the transition zone (TZ) in between them, were compared via integrative physiological, volatile-metabolomic, and transcriptomic analyses to identify the key metabolites and regulatory mechanisms involved in fragrance formation. During heartwood formation, gradual starch grain loss was accompanied by the deposition of lipids and extractives in the cell lumen. Extracts of terpenoids were synthesized and accumulated in the heartwood, including monoterpenoids (limonene and p-cymene) and sesquiterpenes (cubebene and guaiadiene); these were identified as being closely related to the special fragrance of the wood. Additionally, the expression of transcripts showed that the genes related to primary metabolism were specifically upregulated in the SW, whereas genes annotated in terpenoid biosynthesis were specifically upregulated in the HW. Therefore, we speculated that terpenoid biosynthesis occurs in situ in the HW via the HW formation model of Type-III (Santalum) using the precursors that were produced by primary metabolism in the SW. The expression levels of transcription factors (e.g., MYB, WRKY, and C2H2) acted as the major regulatory factors in the synthesis of terpenoids. Our results explain the special fragrance in P. hui and broaden the current knowledge of the regulatory mechanisms of fragrance formation. This work provides a framework for future research that is focused on improving wood quality and value.

Variation of wood color and chemical composition in the stem cross-section of oak (Quercus spp.) trees, with special attention to the sapwood-heartwood transition zone

The transformation of sapwood (SW) into heartwood (HW) during ageing of wood tissues is the result of physiological and biochemical changes initiated in the transition zone (TZ). These changes contribute to the evolution of active (living) wood cells in SW into less/non-active (dead) wood cells in HW. Previous studies established that the biosynthesis of extractive contents is the most prominent process that occurs in the TZ. To improve our understanding of the extent and characteristics of the TZ in oak wood, the present study reports the results of color parameters (using CIELab color space) and molecular structure and composition of polysaccharide and lignin compounds (using FTIR-ATR and Py-GC–MS). For that purpose, six wood cores from individual living oak (Quercus spp.) trees were collected from two forests with similar environmental conditions, located in the Basque Country (Northern Spain). The color data indicated significant differences between SW, TZ and HW by showing that SW samples were characterized by higher hue (h°) and lower redness (a*) values than the HW, and intermediate values for the TZ. They also suggested that the variations of wood color from SW to HW occur gradually, along a wide TZ counting 4–10 measurement points in a row, depending on the tree. Furthermore, FTIR and Py-GC–MS data gave evidence of the variation trends of polysaccharide and lignin contents in the radial direction, through various FTIR ratios (1735/1325, 1590/1735, 1590/1230, and 1230/1325 cm−1) and one pyrolysis ratio (acetic acid/total polysaccharide: Ps01/Tot_Ps). The observed variations in this present study suggest that the cross-sectional transition patterns can be related to the continuous lignification process of xylem parenchyma cells, as well as the storage of polysaccharide compounds. These results contribute to our fundamental knowledge on the TZ, which may be valuable in research and industrial applications where a clear delimitation of sapwood and/or heartwood is required.

Compressive Strength of Aged Timber Members in Traditional Building: Considering Differences in Heartwood and Sapwood

This paper compares the parallel-to-grain compressive strengths of wood sample specimens with defects with those of the associated timber log samples. The Chinese fir (Cunninghamia lanceolata) was examined using the static test method. We analyzed the effects of sampling position along the radial direction of the log sample and the age of timber on the parallel-to-grain compressive strength. We then developed time-dependent strength models of the heartwood (HW) and sapwood (SW). These models can be used to evaluate the strength of an aged timber member, using only the service duration, without taking material samples. The degradation of compressive strength over time was then analyzed using an existing multivariate time-dependent model that includes the stress level. The failure strength of the HW was found to be close to that of the SW when at low stress levels. The estimates of the compressive strength of timber members based on these models were better than those recommended by the Chinese National Standard.

Changes in the intensity of heartwood formation in Scots pine (Pinus sylvestris L.) ontogenesis

Summary An essential stage in woody plant ontogeny (heartwood (HW) formation) determines tree resistance to weather conditions, wood quality (moisture, colour, resistance to biodegradation), and regulates the proportion of functionally active sapwood (SW) in the total trunk biomass. In this study, the patterns of HW formation depending on tree age and cambial age within the same tree were studied in the North-West of Russia in Scots pine in a lingonberry pine forest. It is shown that HW either repeats the trunk profile or shows a maximum proportion on average at the height of 1.5 m. Models using the square root transformation and logarithm transformation have been proposed to predict the number of annual rings in HW depending on the cambial age. Multiple regression is proposed to predict the radial width in HW. Validation of the developed models on random trees gave a good result. HW formation begins at the age of 17–18 years and continues at the rate of 0.3 rings per year for 20–30-year-old trees, 0.4–0.5 rings per year for 70–80-year-old trees, and about 0.7 rings per year for 180-year-old trees. The lifespan of xylem parenchyma cells ranged from 10–15 years in 20-year-old trees to 70 years in 180-year-old trees. At the age of the previous felling (70–80 years) the HW area in the trunk biomass is about 20%, and in 180-year-old pine forests, it increases to 50%. These data can be used to assess the role of old-growth forests in carbon sequestration.

Presence of tyloses in 6 Korean oak species for production of liquor barrels and correlation of retention of large vessel lumen

This study was conducted to devise ways of promoting the use of deciduous trees that have increased in number with climate change. For six oak species commonly utilized to produce liquor barrels, normal wood and tension wood were classified by part. Then, both large vessel lumen area and tyloses were quantitatively assessed. The findings showed that in both normal and tension woods, large vessel lumen area was largest in sapwood, followed by heartwood and juvenile wood. Tyloses were found in both normal and tension woods of all the six species, but the number of tyloses varied according to species. It was heart wood that contained the highest amount in both normal and tension woods. It was also revealed that the number of tyloses decreased with the growing area of large vessel lumen. This study will provide fundamental data to decide oak tree species for the production of liquor barrels.

COMPARATIVE GC-MS ANALYSIS OF RAKTACHANDANA ( Pterocarpus santalinus L.f. ) HEARTWOOD AND ITS SUBSTITUTE USHIRA( Chrysopogon zizanioides( L.) Roberty ) ROOTS

Ayurvedic literature suggests use of readily available substitute drugs (Abhava Pratinidhi Dravya) with similar properties for genuine drugs in its scarcity or absence ( Abhava Dravya). This concept of drug substitution is validated in very few pairs. Hence the present work aims to identify and compare the chemical composition of crude methanolic extract of heart wood of Raktachandana ( Pterocarpus santalinus L.f. ) an Abhava Dravya and roots of Usira (Chrysopogon zizanioides ( L.) Roberty ) an Abhava Pratinidhi Dravya using GC- MS. 14 compounds were identified in Raktachandana while 41 compounds were identified in Usira. In both the extracts sesquiterpenes were the major compounds identified followed by monoterpenes. The presence of sesquiterpene, beta eudesmol was identified in both the plants with a peak area of 14.72% and 1.05% in Raktachandana and Usira respectively. Compounds showing similar pharmacological actions were detected in both the extracts. The study supports the legitimacy behind the logic of suggesting Usira as a substitute for Raktachandana.

Corrective Interventions to End-Splitting and Surface Cracking in Kenya Grown <i>Eucalyptus grandis</i> Poles

This study determined the effect of three pole pre-drying handling techniques, on end-splitting and surface checking in Eucalyptus grandis poles from highland and low land areas in Kenya. A total of 144 Eucalyptus grandis trees were sampled from two sites; Kericho, representing the wet highlands and Londiani representing the drier lowlands regions of Kenya. Pole samples from both sites were subjected to the three pre-drying handling techniques for the first 30 days after felling and allowed to dry to the required moisture level under observations. The number of end splits and surface checks on each sample pole were counted and the length of the worst ones was measured in millimeters after every 15 days until all the poles reached 25% MC. The sap wood and heart wood ratios were determined from selected samples. Results showed that on the overall, poles from high land areas had the highest sapwood proportions and similarly had the highest number and the longest end splitting and surface checks. On the other hand, pre-drying techniques that allowed felled trees to dry slowly with their foliage intact for the first 30 days of felling produced the best quality poles, with fewer and shallower end splits and surface checks. The study recommended that felling and leaving poles to dry slowly with foliage intact be considered in reducing losses incurred as a result of wood stresses during drying of poles.

Compatibility of preservative with adhesive in Eucalyptus grandis laminates

ABSTRACT The fundamental factors responsible for the complexities in adhesive bonding of preservative-treated wood are predominantly wood species, preservative composition, and adhesive system. It is post-effect of these factors that process variables such as assembly times and bonding pressure exert secondary influences on adhesive-bond development in preservative-treated laminates. Hence, this study investigated the effect of copper azole (CA) and disodium octaborate tetrahydrate (DOT) impregnations on E. grandis heartwood (HW) and sapwood (SW) bonding with melamine–urea–formaldehyde and polyurethane adhesives. Based on the adhesives and bonding conditions investigated, the CA and DOT-treated E. grandis laminates do not satisfy at least one of the shear strength and delamination requirements according to EN 14080:2013. Contrary to delamination, shear strength was significantly affected by the HW–SW difference. This study established the basis for further considerations on adapting bonding conditions for improved adhesive-bond performance in CA and DOT-treated E. grandis laminates towards manufacturing durable hardwood composite for tropical and subtropical environments.