<jats:p>Apart from a mixture of bacteriohopanetetrols already found in other <jats:italic>Acetobacter</jats:italic> species, four new 3β‐methylhopanoids have been isolated from <jats:italic>Acetobacter europaeus.</jats:italic> All of them present an ether linkage between a bacteriohopanetetrol or a bacteriohopanepentol and a carbapseudopentose moiety often found in bacterial hopanoids. Three of these ethers were shown by comparison with synthetic reference hopanoids to posess a supplementary methyl group at C31. This novel series of methylhopanoids may be the precursor of yet unidentified molecular fossils found in sediments. [<jats:italic>methyl</jats:italic> ‐<jats:sup>2</jats:sup>H<jats:sub>3</jats:sub>]Methionine was efficiently incorporated into the 31‐methylhopanoids with retention of all three deuterium atoms in the transferred methyl group. This labelling pattern might be consistent with a rather rarely found methylation reaction of an enol.