Studies on the Lignin of Eucalyptus regnans F. Muell. V. Ethanol Lignin

Abstract

Lignin has been isolated from Eucalyptus regnans F. Muell. by refluxing with ethanolic hydrogen chloride, and the product separated into an ether-insoluble ethanol lignin-A and an ether-soluble ethanol lignin-B. Ethanol lignin-A has an equivalent weight of 1400 and, on the assumption that the molecular weight is of this order, contains two ethoxyl and nine methoxyl groups. Acetic anhydride and benzoyl chloride in pyridine yield respectively a hepta-acetate and heptabenzoate, while benzoyl chloride in aqueous alkali yields a pentabenzoate. Diazomethane yields a dimethyl derivative which gives a penta-acetate on acetylation. Schotten-Baumann benzoylation of this dimethyl derivative yields a dibenzoate. Two carbonyl groups are present, as shorn by the formation of a bisphenylhydrazone and a bis-p-nitrophenylhydrazone. The data are consistent with the formula C₅₉H₃₈O₁₀(OC₂H₅)₂(OCH₃)₉(OH)₇.