LAUSR

A mild methylation method is detailed in this work. It uses 1N NaOH to deprotonate primary and secondary hydroxyl groups for short time. Excess 1N NH4OH (1.00 ml, pH 11.4) is added, followed by NaHCO3 to make the carbonate esters by nucleophilic substitution of the deprotonated primary and secondary OH groups. The reaction conditions include; ambient temperature and for an appropriate time. Then NaBH4 is added and the reaction conditions are; standing at ambient temperature for at least 4 hours. This converts the carbonate esters to the methyl ethers. Work-up includes transferring the methylated switchgrass leaf section to a vial containing 1N HCl (1.00 ml). The leaf needs to be submerged in the acid. The reaction conditions include; heating the reaction vessel at 72°C, for 4 days. The contents of the vial are reduced in volume to syrup with a stream of air. The mixture dissolves completely in methanol. Mass spectrometry is done on a methanol solution in the negative ion ESI mode. The mass spectral interpretation reveals the presence of methylated glucan amimo acids and glucan dipeptides. The molecules identified were per-O-methylated glucans linked to either serine or asparagine through a di-(hydrido) di-phospho di-hydratephe moeity. It is possible that one ion is derived from a phosphorylated tyrosine linked to either the serine or asparagine linked to an originally di-phospho cellulo-glucan.