Study On The Effect Of Larix Olgensis Extract On Wood Preservation

In this paper, heartwood, sapwood and bark of Larch were used as raw material to obtain 15 kinds of extractions by refuxing with Et₂O, CHCl₃, (CH₃)₂O, MeOH and H₂O respectively. Antibacterial activities of 15 kinds of extractions obtained on four wood-inhabiting fungi such as Coriolus versicolor, Gloeophyllum trabeum, Chaetomium globosum and Paecilomyces variot Bainier were investigated by use filter paper method. It was found that MeOH extraction of heartwood has better inhibition effect on Coriolus versicolor and Chaetomium globosum;H₂O extraction of bark has also better inhibition effect on Coriolus versicolor, Gloeophyllum trabeum and Chaetomium globosum, and Et₂O extraction of bark has the similar effect on Paecilomyces variot Bainier, but Et₂Oand CHCl₃ extraction of sapwood has little inhibition effect Coriolus versicolor, Chaetomium globosum and Paecilomyces variot Bainier.Polar wood preservation test was carried on by use extractions with better inhibition effect and typic ACC wood preservative. At the same time, the growths of wood-inhabiting fungi in samples were observed by use SEM. The results showed that minimum consistency of MeOH extraction of heartwood is close to that of ACC when Coriolus versicolor was inhibited to standard I , which indicate the extraction and ACC have no obvious differences in antibacterial activities. Et₂O, CHCl₃, (CH₃)₂O and MeOH extractions of heartwood and bark were analyzed by GC-MS. Analysis results show that there are 29 kinds of substances in heartwood and 18 kinds of substances in bark which match degree is more than 90. And the main components in heartwood conclude phenolic compounds, derivatives of oxygenated phenolic, terpenoids, saturated and un saturated fatty acid and their esters and those in bark are phenolic compounds, derivatives of oxygenated phenolic, alkyl derivatives of benzene, terpenoids and long chain carbon alkene.It was found by freshwater fish acute toxicity experiment that zebrafish LC50 of H₂O extraction of bark with 72h is 18.75mg/L but that of ACC is 2.00mg/L, which show acute toxicity of the extraction is lower than ACC.