Abstract:

Objective: This study focused on the extract content and chemical composition of different parts of oak, with the aim to provide scientific guidance for the processing and utilization of oak wood. Method: This study used the oak from Henan Province as the research object, using the Chinese wood chemical analysis standard, combined with Fourier transform infrared(FTIR) and gas chromatography mass spectrometry(GC-MS) method. The content and composition of the cold/hot water extract, 1% sodium hydroxide extract and phenyl alcohol extract from the bark, sapwood and heartwood with different heights in the trunk of Quercus variabilis and Quercus acutissima were analyzed in detail. Result: The results showed that the contents of cold/hot water and 1% NaOH extractives of Q. variabilis bark, sapwood and heartwood at different heights were significantly higher than those of Q. acutissima. Among them, the bark extractive had the highest content, the sapwood was the second, and the heartwood had the lowest content. The extract content had a tendency to be high at both ends and low in the middle with the height of the trunk. For the content of phenyl alcohol extract, the oak bark was much higher than the sapwood and heartwood, but the difference between two oaks was small and did not change with the height for the sap/hearwood. The FTIR spectra showed that the bark and sap/heartwood of Q. variabilis and Q. acutissima were obviously different. According to the absorption peak intensity, the bark might contain more alcohols, fatty acids, aromatics and alkane structural compounds, and there should be more acids, alcohols and unsaturated hydrocarbons in the sap/heartwood. The Result: s of GC-MS analysis showed that both the bark and sap/heartwood contained a small amount of alkane alcohols, esters and unsaturated alkenes. The bark contained abundant friedelin and its isomers. The sap/heartwood included γ-sitosterol et al. Conclusion: The main chemical components of the extracts of Q. variabilis and Q. acutissima in bark and sap/heartwood have a large difference, and there also have a certain difference in component contents. The height of the trunk also has a certain influence on the extract content of these two oaks. The middle trunk accumulated more cold/hot water and 1% NaOH extractives, but no significant compositional differences were found. In the actual processing and production of wood, the differences in the content and bark, sap/heartwood extractives of the two kinds of oak wood should be fully considered to provide a reasonable, comprehensive and high-value utilization processing plan.

Key words: Quercus variabilis, Quercus acutissima, extract content, GC-MS(gas chromatography mass spectrometry), chemical composition