The structures of polysaccharides obtained from hot water extract of Mycobacterium tuberculosis strain Aoyama B were investigated. The polysaccharides fractionated by moleculer sieve-, ion exchange- and affinity-chromatographies and ethanol precipitation were analysed. Main polysaccharides clarified from the results are ; 1) arabinomannan in which arabinan core and mannan core coupled alternately, having average molecular weight of about 12000, 2) mannan with many side chains and average molecular weight of about 5000, 3) a mixture of lipoarabinomannan and lipomannan with fatty acid ester of about 18%, 4) acidic lipoglucan consisting of 6-O-methyl-D-glucose, glucose, 3-O-methyl-D-glucose, glyceric acid, and 6-9 moles of lower fatty acid esters, 5) glycogen-like highmolecular glucan, 6) low-molecular mannan and glucan.
