Antioxidant Properties derived from Stromata of Xylaria species collected from Tropical Forest in Thailand

作者：Krittapong Orachaipunlap^*; Nuttika Suwannasai; Sutee Chutipaijit; Anthony Whalley J S; Prakitsin Sihanonth

来源：Research Journal of Biotechnology, 2015, 10(3): 13-19.

• Xylaria sp.
• stromata
• fungi
• antioxidant
• tropical forest

Fungi in the genus Xylaria are common wood decay fungi. They have been shown to be potential sources of novel natural products for utilization in medicine, agriculture and industry. In this study, stromata of Xylaria spp. were collected from Trat Agroforestry Research and Training Station. Fresh specimens of Xylaria spp. were cultured on Potato Dextrose Agar (PDA) for 14 days and then transferred to Malt Extract Broth (MEB). All isolates were cultured under static condition for 6 weeks and extracted with ethyl acetate. Antioxidant properties of stromatic Xylaria spp. were determined in vitro by ABTS and DPPH assays. Free radical scavenging was recorded by Trolox equivalent antioxidant capacity (TEAC) in ABTS assay and EC50 in DPPH assay.
The ethyl acetate extracts of four stromatic Xylaria spp. (TR25, TR34, TR46 and TR51) showed strong activities against both ABTS (TEAC 20.7 +/- 0.08, 15.16 +/- 0.03, 11 +/- 0.03 and 19.66 +/- 0.11 mu M Trolox respectively) and DPPH assay (EC50 36.92 +/- 0.96, 70.53 +/- 1.04, 102 +/- 2.67 and 49.08 +/- 1.74 mu L respectively). The correlation coefficients from regression analysis showed a positive correlation between total phenolic/flavonoid contents and TEAC for ABTS assay of all crudes extracted and showed a negative correlation between total phenolic/flavonoid contents and the EC50 for DPPH radical scavenging. Moreover, GC/MS results are indicated the various phenolic compounds in selected crude extracts. In conclusion, cultures obtained from stromata of Xylaria spp. may have potential as natural antioxidant products.

• 出版日期2015-3