Straight Chain Hydrocarbons A Race

The first structural study was concerned with the hydrocarbons of a strain from the culture center at Cambridge. C27, C29 and C31 dienic compounds, series (1), were thus shown (75) to account for more than 90 percent of the hydrocarbons extracted from B. braunii biomass with acetone (it was observed in subsequent studies (27) that only external hydrocarbons are recovered using this solvent). Ozonolysis of the hydrocarbon mixture and analysis of the resulting aldehydes by GCMS 

In addition to this cis series, a second dienic series (2) was first identified in a French strain originating from Lake Grosbois (16). Freezing an hexane solution of the external hydrocarbons of this strain led to the separation of a solid mixture comprising the major compounds of the second dienic series. Oxidative and spectroscopic investigations indicated the same general structure as in series (1), but with trans stereochemistry (IR stretch at 970 cmof the C(co9)-C(colO) double bond in the compounds of series (2). 

The mono-unsaturated odd carbon numbered C23-C27 hydrocarbons which occur as minor constituents in a very limited number of 

The synthesis of only one alkadiene of B. braunii has been performed electrochemical coupling of undecen-ll-oic acid with oleic acid via a Kolbe reaction afforded the heptacosa-l,18(Z) diene (1) (26). 

In relation of their biosynthesis, it is interesting to note that all the hydrocarbons from the A race possess an odd carbon number and a terminal double bond moreover all the dienes and the two trienes identified up to date exhibit C((o9)-C(a)10) unsaturation. 

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