A novel C35 terpene and its monounsaturated analogue were isolated from cultures of Acetobacter xylinum, together with traces of their C36 homologues. These substances were found to be hopane derivatives substituted by a five-carbon chain bearing four vicinal hydroxyl groups. For the parent hydrocarbon the term bacteriohopane is proposed. The elucidation of the structures utilized high-resolution mass spectrometry of the terpenes, degradation to C32 hydrocarbons and detailed mass-spectrometric comparison of these with C32 hydrocarbons synthesized from known pentacyclic triterpenes. High-resolution mass-spectral data of the terpenes are presented. N.m.r. data are in agreement with the proposed structures, which are further supported by the isolation from the same organism of 22-hydroxyhopane and derivative hopene(s).
The high-resolution mass
spectra of benzo[b]thiophen, some alkyl and aryl derivatives, and the sulphone
and 2,3-dihydrosulphone have been obtained; compositions of all significant
ions in the spectra have been determined. Fragmentations of the unoxidized compounds
are dominated by losses of C2H2 and CS units, while the
sulphones undergo initial isomerization to cyclic sulphinates followed by
expulsion of SO and fragments containing a C-O bond. Structures have been
suggested for most of the ions observed.
Algorithm for comprehensive analysis of datasets from hyphenated high resolution mass spectrometric techniques using single ion profiles and cluster analysis