Topochemical investigation on phenolic deposits in the vessels of afzelia (Afzelia spp.) and merbau (Intsia spp.) heartwood

Koch, Gerald; Richter, Hans; Schmitt, Uwe

doi:10.1515/hf.2006.099

Cited by 33 publications

(22 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This spectral behaviour can be explained by the presence of chromophoric groups, for example, conjugated double bonds. The higher degree of conjugation stabilises p-p* transitions resulting in absorbance bands shifted to higher wavelengths (Goldschmid 1971) that can be detected by UV microspectrophotometry (Koch et al 2006). Against this, the spectra of extractives in the tissue of NMM-treated B. insigne were characterised by additional maxima in the range of 244-248 nm (Fig.…”

Section: Detection Of Nmm With Cellular Uv Microspectrophotometrymentioning

confidence: 96%

“…Note the higher deposition of NMM in cell lumens of B. ceiba; Tissues of axial parenchyma in B. ceiba (c) and B. insigne (f) treated with 20 % ML with extractives (tannins) deposited in cell lumens characterised by high absorbance intensities of 0.68-1.00. Size of UV pictures: a 57.50 9 39.00 lm = 36,267 pixels or measuring points; b 39.50 9 30.25 lm = 19,398 pixels or measuring points; c 60.75 9 55.00 lm = 53,924 pixels or measuring points; d 51.00 9 45.50 lm = 37,515 pixels or measuring points; e 43.50 9 42.00 lm = 29,575 pixels or measuring points; f 63.00 9 35.25 lm = 35,926 pixels or measuring points conglomerations of high absorbance values (abs 280nm 0.68-1.00) compared with the surrounding cell wall tissue (Koch et al 2006). The impregnation of NMM into the different morphological regions of B. ceiba and B. insigne wood tissue was (basically) confirmed by the analyses of point measurement absorbance spectra, which are shown in Figs.…”

Section: Detection Of Nmm With Cellular Uv Microspectrophotometrymentioning

confidence: 99%

See 1 more Smart Citation

Impregnation of Bombax ceiba and Bombax insigne wood with a N-methylol melamine compound

et al. 2012

Self Cite

View full text Add to dashboard Cite

Methylated N-methylol melamine (NMM) is known for its ability to enhance physico-mechanical properties, anti-fungal ability, and hydrophobicity and was therefore used to impregnate two less used and non-durable wood species from Myanmar, Bombax ceiba and Bombax insigne. Solution uptake, weight percent gain and nitrogen content were increased by increasing melamine concentrations with B. ceiba always achieving higher values compared with B. insigne. According to the leaching results, a higher degree of condensation after curing as well as a better crosslinking of NMM could be obtained at higher temperatures. However, both curing temperatures used (90 and 120°C) resulted in almost the same amount of nitrogen fixed in the cell wall. UV microspectrophotometry confirmed the penetration of the NMM into different morphological regions of wood tissues, which was again supported by the analysis of point measurement spectra of treated and untreated specimens.

show abstract

Section: Detection Of Nmm With Cellular Uv Microspectrophotometrymentioning

confidence: 96%

Section: Detection Of Nmm With Cellular Uv Microspectrophotometrymentioning

confidence: 99%

Impregnation of Bombax ceiba and Bombax insigne wood with a N-methylol melamine compound

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…Koch et al (2006) found pure Robinetin in heartwood vessels of Intsia spp. Differing from observation, the absorbance spectra indicate that, in the heartwood of Robinia, these flavonoids are not present in their pure form (Fig.…”

Section: Juvenile Woodmentioning

confidence: 94%

Chemical composition and natural durability of juvenile and mature heartwood of Robinia pseudoacacia L.

Latorraca

Dünisch²,

Koch

2011

An. Acad. Bras. Ciênc.

Self Cite

View full text Add to dashboard Cite

The aim of this study was to characterize the properties of juvenile and mature heartwood of Robinia pseudoacacia L. (black locust). The content, the composition, and subcellular localization of heartwood extractives were studied in 14 old-grown trees from forest sites in Germany and Hungary, as well as in 16 younger trees of four clone types. Heartwood extractives (methanol and acetone extraction) were analysed by HPLC-chromatography. UV microspectrophotometry was used to localize the extractives in the wood cell walls. The natural durability of juvenile and mature heartwood was analysed according to the European standard EN 350-1. Growth analyses, as well as the chemical analyses, showed that in Robinia the formation of juvenile wood is restricted to the first 10-15 years of cambial growth. In the heartwood high contents of phenolic compounds and flavonoids were present, which were in high concentrations in the cell walls of the axial parenchyma and of the vessels. In the juvenile heartwood, the content of these extractives is significantly lower than in the mature heartwood. In agree, the juvenile heartwood had a lower resistance to decay by Coniophora puteana (brown rot fungus) and Coriolus versicolor (white rot fungus) compared to the mature.

show abstract

“…Extractions were carried out with acetone/water (9:1) and methanol/-water (3:1) at 60 °C under constant pressure at 100 atm and a static equilibration treatment of 5 min. according to Koch et al (2006).…”

Section: Chemical Analysis Of Heartwood Extractivesmentioning

confidence: 99%

The Assimilate Partitioning Importance for Heartwood Extractives Formation in Robinia Pseudoacacia l. of Different Ages

Dünisch¹,

Latorraca

2015

Floresta Ambient.

View full text Add to dashboard Cite

This study aimed to investigate the influence of tree age on the assimilates partitioning and its significance for the formation of heartwood extractives in Robinia pseudoacacia L. (black locust). Assimilate translocation in 6-and 15-year-old plants was measured in May and August 2006 using the 14 CO 2 feeding method. The heartwood extractives content in the sapwood-heartwood transition zone and in individual tree rings of the pure heartwood were analysed by HPLC-chromatography. All plants, buds and young leaves showed the strongest 14C specific activity compared to other plant parts in May and August( 14 C specific activity in buds/leaves of 6-years old plants: 35.2-37.0%, 15-years old plants: 31.4-32.2%). However, in plants labelled in August 2006 at the sapwood-heartwood transition zone also showed a strong assimilates sink, while only small amounts of assimilates were translocated to the sapwood-heartwood transition zone in the plants labelled in May 2006. The amount of assimilates transported to the sapwood-heartwood transition zone was significantly higher in the 15-year-old plants compared to the 6-year-old plants. This was monitored by a higher content of extractives in the heartwood formed by the older plants compared to heartwood formed by the younger plants. The results indicate that uneven assimilate partitioning in younger and older black locust plants affects the heartwood extractives formation, which might lead to a lower natural durability of the heartwood formed by younger trees compared to heartwood formed by older trees. Keywords

show abstract

Topochemical investigation on phenolic deposits in the vessels of afzelia (Afzelia spp.) and merbau (Intsia spp.) heartwood

Cited by 33 publications

References 20 publications

Impregnation of Bombax ceiba and Bombax insigne wood with a N-methylol melamine compound

Impregnation of Bombax ceiba and Bombax insigne wood with a N-methylol melamine compound

Chemical composition and natural durability of juvenile and mature heartwood of Robinia pseudoacacia L.

The Assimilate Partitioning Importance for Heartwood Extractives Formation in Robinia Pseudoacacia l. of Different Ages

Contact Info

Product

Resources

About