Ozonolytic cleavage of authentic and pancreatic dolichyl mannopyranosyl phosphates: determination of sugar configuration in the fragments with alpha- and beta-mannosidases.

Exposure of authentic dolichyl α-D-¹⁴C]mannopyranosyl phosphate ($\text{I}$) or calf pancreas dolichyl ¹⁴C]mannopyranosyl phosphate ($\text{II}$) to ozone at ?70° in pentane followed by treatment with triphenylphosphine gave water-soluble fragments in 65–95% yield. The radioactive products obtained were similar; the major fragment had a mobility on tlc greater than that of mannose but lower than that of citronellyl β-D-mannopyranosyl phosphate. The electrophoretic behavior of the fragments indicated that they possessed intact phosphodiester linkages. α-Mannosidase released ¹⁴C]mannose from the fragments of $\text{I}$ but not from the fragments of $\text{II}$; however, the latter were susceptible to β-mannosidase indicating that the pancreatic mannolipid contains a β-linked mannosyl residue.