Rhodotorula glutinis mannan

An apparently similar type of mannan is formed exocellularly by a certain Rhodotorula species. Rhodotorula glutinis mannan has a specific rotation of —78°, and consists of a linear chain of at least 90 units, which is overoxidized somewhat with periodate, consuming 0.61 mole of oxidant with formation of 0.07 mole of acid per mole of mannose residue after two days. Partial hydrolysis gives 4-0-)3-D-mannopyranosyl-D-mannose and 0-j8-D-mannopyranosyl-(1 3)-0-/8-D-mannopyranosyl-(1 4)-D-mannose, but a)8-D-(l- 4)-linked manno-triose is not detectable. Since 2-0-j8-D-mannopyranosyl-D-erythritol is obtained from the mannan by a Smith degradation, an alternating ar-... 

The mannan from Rhodotorula glutinis contains87 alternating (l- 3)- and (1— 4)-Iinked /3-D-mannopyranosyl residues (repeating structure 8). The absence of consecutive, (1— 3) and (1—>4) linkages... 

The synthesis of an alternating antigenic jS-(l—>3)-jS-(l—>4)-mannan common to Rhodotorula glutinis, Rhodotorula mucilaginosa, and Leptospira biflexa provided the occasion for the comparison of linear and block approaches. A linear synthesis was first undertaken and provided a relatively straightforward access to the hexaose 313 (Scheme 51).134,146 The most noteworthy feature of this synthesis was the protection of the /1-donor 305 destined to become the - 4)-D-mannopyranosyl-/i-(l unit in the polymer as the 4-methoxybenzylidene acetal rather than as the simple benzylidene acetal employed in the /1-donor 301 precursor to the ultimate 3) - D- m an n opy rano -... 

D. Crich, W. Li, and H. Li, Direct chemical synthesis of the /J-mannans Linear and block synthesis of the alternating /1-(1—>3)-/ -(l—>4)-mannan common to Rhodotorula glutinis, Rhodotorula mucilagi-nosa, and Leptospira biflexa, J. Am. Chem. Soc., 126 (2004) 15081-15086. 

Figure 10. NMR spectra of mannans of Rhodotorula glutinis obtained from deuterium-labelled glucose precursors (6- H2, 5- H, and 3- H derivatives)...

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