Barry K M, Davies N W, Mohammed C L
CRC for Sustainable Production Forestry, GPO Box 252-12, Hobart, Tasmania 7001, Australia.
Phytochem Anal. 2001 Mar-Apr;12(2):120-7. doi: 10.1002/pca.548.
The first detailed analysis of the phenolic constituents of the reaction zones (tissue of antimicrobial defence) from the sapwood of a Eucalyptus spp. is presented. Plantation-grown Eucalyptus nitens trees with stem decay resulting from pruning wounds were sampled and extracts were prepared from healthy sapwood and from reaction zone tissue. Analysis by HPLC with ESI-MS revealed that a diverse range of hydrolysable tannins are present in both healthy sapwood and in reaction zone extracts, including over 30 gallotannins, ellagitannins and phenols. Eight tannins were unequivocally identified, including the gallotannins tri-O-galloyl-beta-D-glucose, tetra-O-galloyl-beta-D-glucose and penta-O-galloyl-beta-D-glucose, and the ellagitannins pedunculagin, tellimagrandin I, casuarinin, casuarictin and tellimagrandin II. The phenols gallic acid, ellagic acid and catechin were also identified. The ellagitannins (particularly pedunculagin) are considerably more abundant in the reaction zone than in the healthy sapwood and may contribute to the effectiveness of the reaction zone as an antimicrobial barrier.
本文首次对桉属植物边材反应区（抗菌防御组织）的酚类成分进行了详细分析。对因修剪伤口导致茎干腐烂的人工种植尼氏桉树木进行采样，并从健康边材和反应区组织中制备提取物。采用电喷雾电离质谱联用高效液相色谱法分析表明，健康边材和反应区提取物中均存在多种可水解单宁，包括30多种没食子单宁、鞣花单宁和酚类。明确鉴定出8种单宁，包括没食子单宁三 - O - 没食子酰基 - β - D - 葡萄糖、四 - O - 没食子酰基 - β - D - 葡萄糖和五 - O - 没食子酰基 - β - D - 葡萄糖，以及鞣花单宁栓皮素、tellimagrandin I、苏木精、casuarictin和tellimagrandin II。还鉴定出了酚类物质没食子酸、鞣花酸和儿茶素。鞣花单宁（尤其是栓皮素）在反应区中的含量比健康边材中高得多，可能有助于反应区作为抗菌屏障发挥作用。
