Comparative analysis of modern and ancient buried Phoebe zhennan wood: surface color, chemical components, infrared spectroscopy, and essential oil composition

We compared the chemical components and essential oils of ancient buried Zhennan (Phoebe zhennan) wood with those in samples from living trees. After removal of the carbon layer the recovered Zhennan exhibited a dark green color, which differed from the yellow color of the living samples. Low molecular weight components (including hot-water and toluene-alcohol extractives), hemicellulose, and 1 % NaOH solubility in the recovered wood were greatly degraded. Degradation of cellulose was minor. Moreover, the ancient wood had somewhat more klason lignin than the modern wood. Fourier transform infrared (FTIR) analysis gave further evidence on the differences in chemical components. According to the GC–MS results, naphthalene derivatives were detected in the essential oils from both the modern and recovered wood. The delicate fragrance of the modern and recovered wood may be attributed to the aromatic constituents as identified by GC–MS.