人工培养菌种茯苓菌丝体多糖的分离、组成和分子量

由人工培育的茯苓菌种 (5·78号 )在含麸皮的培养液中于 2 5℃培养 1 8天得到茯苓菌丝体 .分别用9g LNaCl水溶液、热水、0 .5mol LNaOH和 88%甲酸从菌丝体中提取 7种多糖依次为 :ab PCM1、ab PCM2 I、ab PCM2 II、ab PCM3 I、ab PCM3 II、ab PCM4 I、ab PCM4 II,并从培养液中提取一种多糖ab PCM0 .红外光谱 (IR)、气相色谱 (GC)和1 3C NMR分析结果表明ab PCM0至ab PCM3 I多糖主要由α (1→ 3 ) D 葡萄糖、α D 甘露糖、β D 半乳糖和乙酰葡萄糖胺组成 ,而且随提取过程进行 ,葡萄糖含量逐渐增加 ,即从杂多糖到α 葡聚糖 .ab PCM3 II、ab PCM4 I和ab PCM4 II则主要是 β (1→ 3 ) D葡聚糖 .有趣的是 ,α 葡聚糖和 β 葡聚糖共存在该菌丝体的碱水提取液中 .由粘度法和光散射法测定了多糖的特性粘数 η]和重均分子量Mw .ab PCM0、ab PCM1、ab PCM2 I、ab PCM2 II、ab PCM3 I和ab PCM4 II多糖的Mw 值分别为 7 7× 1 0 4、5 2× 1 0 4、5 0× 1 0 4、2 4 3× 1 0 4、65 2×1 0 4和 2 5 5× 1 0 4.

ISOLATION,CHEMICAL COMPONENTS AND MOLECULAR WEIGHTS OF POLYSACCHARIDES FORM PROIA COCOS MYCELIA WITH CULTIVATED STRAIN

Poria cocos mycelia were cultivated from artificial strain No.5·78 in medium containing bran at 25℃ for eighteen days.Seven polysaccharides coded as ab-PCM1,ab-PCM2-I,ab-PCM2-II,ab-PCM3-I,ab-PCM3-II,ab-PCM4-I and ab-PCM4-II were isolated from the poria cocos mycelia by using 9 g/L NaCl aqueous solution,hot water,0 5 mol/L NaOH aqueous solution and 88% formic acid,respectively,and an exo-polysaccharide coded as ab-PCM0 was isolated from the medium.The components of the polysaccharides were analyzed by using infrared spectroscopy(IR),gas chromatography (GC) and 13C-NMR.The results indicated that the polysaccharides from ab-PCM0 to ab-PCM3-I consist of α-(1→3)-D -glucose, α-D -mannose, β-D -galactose,and N -acetyl glucosamine,and with the isolation progress the glucose content in the polysaccharides increased,namely from heteropolysaccharide to α -glucan.The ab-PCM3-II,ab-PCM4-I and ab-PCM4-II mainly consist of β -(1→3)- D -glucan.Interestingly, α -glucan and β -glucan coexist in the alkali extracted solution of the mycelia.The intrinsic viscosities η] and weight average molecular weights M w were determined by viscometry and light scattering.The values of M w for samples of ab-PCM0,ab-PCM1,ab-PCM2-I,ab-PCM2-II,ab-PCM3-I and ab-PCM4-II are 7.7×10 4,5.2×10 4,5.0×10 4,24 3×10 4,65 2×10 4 and 25 5×10 4, respectively.