Hydrocarbons, sterols and hydroxy acids in Antarctic mosses

Abstract

Hydrocarbons, sterols and hydroxy acids were studied in Antarctic mosses, Pottia heimii, Sarconeurum glaciale and Bryum pseudotriquetrum, to characterize their composition and to find their biogeochemical markers, collected from the Miers Valley of southern Victoria Land, Hut Point Peninsula of Ross Island and Vestfold Hills of Queen Elizabeth Land. Hydrocarbons ranging from C_ to C_, including n-alkanes, alkenes and a triterpene (C_H_) were found in the mosses. Four stenols and 3 stanols were identified. The major sterols were 24-methyl- and 24-ethylcholest-5-en-3β-ols, constituting more than 85% of the total sterols in all the mosses. 2-, 3-, ω-1-, ω-hydroxy and 9,16- and 10,16-dihydroxy acids were identified or suggested to be present. The most prominent hydroxy acid was 9,16- or 10,16-dihydroxyhexadecanoic acid. The sterol composition of P. heimii was similar to those of S. glaciale and B. pseudotriquetrum. However, those of hydrocarbons and hydroxy acids differ considerably in the moss samples, suggesting the influences of environmental conditions and microorganisms contained as impurities. On the other hand, high abundances of 24-methyl- and 24-ethylcholest-5-en-3β-ols, along with the dominance of 9,16- or 10,16-dihydroxyhexadecanoic acid, may be useful indicators of mosses in soil, water and sedimentary environments of Antarctica.