Hydroxy and ketonic androstanes: a new class of sterol diagenetic product in peat

3β-Hydroxy-5α-androstan-17-one (epiandrosterone), 5α-androstan-3,17-dione, 3α-hydroxy-5α-androstan-17-one (androsterone), 5α-androstan-3β,17β-diol and 5α-androstan-3α,17β-diol have been identified in the solvent soluble fraction of peat from Bolton Fell Moss (Cumbria, U.K.). The structures and δ13C values of these androstane derivatives indicate a diagenetic origin in sterols also present in the peat and provide the first evidence that cleavage of the C-17 side-chain can occur during early diagenesis, microbial oxidation being the most likely mechanism.