Antifungal activities of acetone-soluble Eusideroxylon zwageri and Potoxylon melagangai crude extracts against white rot
I Jusoh, A Tida Henry, Z Assim, F Badruddin Ahmad, S Ujang
The development of natural wood extracts as a wood preservative is a potentially attractive prospect for the wood preservation industry. This study attempts to evaluate the toxicity of Eusideroxylon zwageri and Potoxylon melagangai extractives as potential wood preservatives. These two species are well-known as among the heaviest and very durable timbers. It has been established that natural durability of timbers are associated by their extractives contain. In this study acetone was used to remove extractives from both wood samples and later was purified by using rotoevaporation process. The toxicity of various extract concentrations against two white rot fungi, Pycnoporus cocinneus and Schizophyllum commune was evaluated on MEA agar for seven days period. Results showed that the mean growth rate of fungi decreased with increased in level of concentrations. Toxicity test indicated that in 1000 ppm concentration, the extractives of E. zwageri reduced the growth rate of P. cocinneus and S .commune by 26% and by 36% while P. melagangai extractives reduced P. cocinneus and S. commune growth rate by 36% and 41%, respectively. Various extract concentrations were used to treat Hevea brasiliensis wood blocks. Following exposure to the white rot fungi for eight weeks it was observed that the weight loss reduced significantly when treated with 15% acetone-soluble extractives. This suggests that transferred extractives have the potential to control decay. However, further studies are required before any concrete inferences can be made on extractives for natural wood preservatives.