不同生長階段靈芝子實體水溶性多醣特性

Abstract

本研究針對三種影響靈芝中多醣及(1,3;1,6)-β-D-葡萄聚醣特性之因素進行探討，包含（一）菌種及菌株之影響、（二）培養方式之影響、（三）子實體生長過程之影響，係以松杉靈芝、赤芝子實體（各兩種菌株），松杉靈芝、赤芝菌絲體及不同生長時期之松杉靈芝子實體為材料，分析其熱水可溶性多醣特性，包含多醣萃取率、不可消化多醣組成分析、(1,3;1,6)-β-D-葡聚醣含量及分 支度、分子量（膠體層析）。八種靈芝子實體（包含赤芝FBGL02、FBGL08 及松杉靈芝FBGT01、FBGT07）及菌絲體（包含赤芝MGL08 及松杉靈芝MGT01-1、MGT01-2、MGT01-3）(1,3;1,6)-β-D-葡萄聚醣含量及分支度結果顯示，四種菌絲體樣品(1,3;1,6)-β-D-葡萄聚醣含量皆顯著高於四種子實體樣品，而在四種子實體樣品中，赤芝含量又高於松杉靈芝。膠體層析結果顯示，四種子實體熱水萃多醣均以低分子量區段（107K > Mw Da）為主，且比例皆高達82.2%以上，四種菌絲體以中分子量區段（708K > Mw > 107K Da）與低分子量區段為主；熱水萃 (1,3)-β-D-葡萄聚醣分子量區段比例在不論在子實體或菌絲體中皆以中分子量區段與低分子量區段為主。不同生長時期松杉靈芝子實體熱水萃總固形物、總醣及粗多醣皆隨生長期增加而有減少之趨勢，但(1,3;1,6)-β-D-葡萄聚醣含量及分支度均隨生長期增加 而增加，從第一期佔多醣中比例3.9% 至第五期25.2% 提升21.3%，且分支度也從0.16（第一期）提升至0.22（第五期），而鹼萃方法能夠增加(1,3;1,6)-β-D-葡萄聚醣萃取量，但會使其平均分支度大幅下降，此現象尤以二至四期子實體最為嚴重，平均分支度降低至0.06－0.09 間。而膠體層析結果顯示，無論在任何時期，水萃多醣以中分子量區段及低分子量區段為主，且隨生長期增加，高分子量區段（Mw > 708K Da）之比例有遞減之趨勢；水萃(1,3)-β-D-葡萄聚醣則隨生長期增加，高分子量區段比例上升且伴隨低分子量比例下降之趨勢。不可消化多醣組成分析結果顯示，各時期熱水萃粗多醣中含有38－51% 之α-葡萄聚醣，且β-葡萄聚醣在熱水可萃多醣中含量比例則隨生長期增加而有上升之趨勢，由第一期5.32%至第五期26.05%，提升20.73%，與前述酵素法結果相近。

The present study investigated the characteristics of hot water extractable polysaccharides and (1,3;1,6)-β-D-glucans from, (1) fruiting bodies of Ganoderma lucidum and G. tsugae with two different strains respectively (FBGL02, FBGL08 and FBGT01, FBGT07), (2) mycelium of G.lucidum (MGL08) and G.tsugae (MGT01-1, MGT01-2, and MGT01-3), and (3) fruiting bodies of G. tsugae in different growing stages. Results showed that the amount of (1,3;1,6)-β-D-glucans in hot water extractable polysaccharides is significantly higher in mycelium culture than fruiting bodies and in fruiting bodies of G. lucidum than G.tsugae. The content of (1,3;1,6)-β-D-glucans, DB (degree of branching), and the ratio in polysaccharides increased as growing stages increased. Alkaline extraction would increased the amount of (1,3;1,6)-β-D-glucans by 154－357% in each growing stage though DB would dramatically drop to 0.06－0.09 in stage 2－5. The results of gel-filtration chromatography showed that the molecular weight distribution of hot water extractable polysaccharides of fruiting bodies in different growing stages were all mainly in MMF (medium molecular weight fraction) and LMF (low molecular weight fraction). The results of composition analysis of indigestible polysaccharides of fruiting bodies in different growing stages showed that the ratio of α-glucans in polysaccharides was up to 51.3% in stage 1 and 38－40% in stage 2 to 5, and the ratio of β-glucans in polysaccharides was proportional to the growing stages (from 5.32 to 26.05%).