人工培养菌种茯苓菌丝体多糖的分离、组成和分子量

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

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.

Poria cocos mycelia were cultivated from artificial strain No. 5 . 78 in medium containing bran at 25 degreesC for eighteen days. Seven polysaccharides coded as ab-PCM1, ab-PCM2-I, ab-PCM2-II, ab-PCM3-I, ab-PCM3-II, abPCM4-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 chroma. tography (GC) and C-13-NMR. The results indicated that the polysaccharides from ab-PCMO to ab-PCM3-I consist of alpha-(1-->3)-D-glucose, alpha-D-mannose, P-D-galactose, and N-acetyl glucosamine, and with the isolation progress the glucose content in the polysaccharides increased, namely from heteropolysaccharide to alpha-glucan. The ab-PCM3-II, ab-PCM4-I and ab-PCM4-II mainly consist of beta-(1-->3)-D-glucan. Interestingly, alpha-glucan and beta-glucan coexist in the alkali extracted solution of the mycelia. The intrinsic viscosities and weight average molecular weights M. were determined by viscometry and light scattering. The values of M. for samples of ab-PCMO, ab-PCM1, ab-PCM2-I, ab-PCM2-II, ab-PCM3-I and ab-PCM4-II are 7.7 x 10(4), 5.2 x 10(4), 5.0 x 10(4), 24.3 x 10(4), 65.2 x 10(4) and 25.5 x 10(4), respectively.